Line data Source code
1 : /*
2 : *
3 : * Copyright (c) 2020-2023 Project CHIP Authors
4 : *
5 : * Licensed under the Apache License, Version 2.0 (the "License");
6 : * you may not use this file except in compliance with the License.
7 : * You may obtain a copy of the License at
8 : *
9 : * http://www.apache.org/licenses/LICENSE-2.0
10 : *
11 : * Unless required by applicable law or agreed to in writing, software
12 : * distributed under the License is distributed on an "AS IS" BASIS,
13 : * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 : * See the License for the specific language governing permissions and
15 : * limitations under the License.
16 : */
17 :
18 : /**
19 : * @file
20 : * Header that exposes the platform agnostic CHIP crypto primitives
21 : */
22 :
23 : #pragma once
24 :
25 : #if CHIP_HAVE_CONFIG_H
26 : #include <crypto/CryptoBuildConfig.h>
27 : #endif // CHIP_HAVE_CONFIG_H
28 :
29 : #include <system/SystemConfig.h>
30 :
31 : #include <lib/core/CHIPError.h>
32 : #include <lib/core/CHIPVendorIdentifiers.hpp>
33 : #include <lib/core/DataModelTypes.h>
34 : #include <lib/core/Optional.h>
35 : #include <lib/support/Base64.h>
36 : #include <lib/support/BufferReader.h>
37 : #include <lib/support/CodeUtils.h>
38 : #include <lib/support/SafePointerCast.h>
39 : #include <lib/support/Span.h>
40 : #include <lib/support/StringBuilder.h>
41 :
42 : #include <stddef.h>
43 : #include <string.h>
44 :
45 : namespace chip {
46 : namespace Crypto {
47 :
48 : inline constexpr size_t kMax_x509_Certificate_Length = 600;
49 :
50 : inline constexpr size_t kP256_FE_Length = 32;
51 : inline constexpr size_t kP256_ECDSA_Signature_Length_Raw = (2 * kP256_FE_Length);
52 : inline constexpr size_t kP256_Point_Length = (2 * kP256_FE_Length + 1);
53 : inline constexpr size_t kSHA256_Hash_Length = 32;
54 : inline constexpr size_t kSHA1_Hash_Length = 20;
55 : inline constexpr size_t kSubjectKeyIdentifierLength = kSHA1_Hash_Length;
56 : inline constexpr size_t kAuthorityKeyIdentifierLength = kSHA1_Hash_Length;
57 : inline constexpr size_t kMaxCertificateSerialNumberLength = 20;
58 : inline constexpr size_t kMaxCertificateDistinguishedNameLength = 200;
59 : inline constexpr size_t kMaxCRLDistributionPointURLLength = 100;
60 :
61 : inline constexpr char kValidCDPURIHttpPrefix[] = "http://";
62 : inline constexpr char kValidCDPURIHttpsPrefix[] = "https://";
63 :
64 : inline constexpr size_t CHIP_CRYPTO_GROUP_SIZE_BYTES = kP256_FE_Length;
65 : inline constexpr size_t CHIP_CRYPTO_PUBLIC_KEY_SIZE_BYTES = kP256_Point_Length;
66 :
67 : inline constexpr size_t CHIP_CRYPTO_AEAD_MIC_LENGTH_BYTES = 16;
68 : inline constexpr size_t CHIP_CRYPTO_SYMMETRIC_KEY_LENGTH_BYTES = 16;
69 :
70 : inline constexpr size_t kMax_ECDH_Secret_Length = kP256_FE_Length;
71 : inline constexpr size_t kMax_ECDSA_Signature_Length = kP256_ECDSA_Signature_Length_Raw;
72 : inline constexpr size_t kMAX_FE_Length = kP256_FE_Length;
73 : inline constexpr size_t kMAX_Point_Length = kP256_Point_Length;
74 : inline constexpr size_t kMAX_Hash_Length = kSHA256_Hash_Length;
75 :
76 : // Minimum required CSR length buffer length is relatively small since it's a single
77 : // P256 key and no metadata/extensions are expected to be honored by the CA.
78 : inline constexpr size_t kMIN_CSR_Buffer_Size = 255;
79 :
80 : [[deprecated("This constant is no longer used by common code and should be replaced by kMIN_CSR_Buffer_Size. Checks that a CSR is "
81 : "<= kMAX_CSR_Buffer_size must be updated. This remains to keep valid buffers working from previous public API "
82 : "usage.")]] constexpr size_t kMAX_CSR_Buffer_Size = 255;
83 :
84 : inline constexpr size_t CHIP_CRYPTO_HASH_LEN_BYTES = kSHA256_Hash_Length;
85 :
86 : inline constexpr size_t kSpake2p_Min_PBKDF_Salt_Length = 16;
87 : inline constexpr size_t kSpake2p_Max_PBKDF_Salt_Length = 32;
88 : inline constexpr uint32_t kSpake2p_Min_PBKDF_Iterations = 1000;
89 : inline constexpr uint32_t kSpake2p_Max_PBKDF_Iterations = 100000;
90 :
91 : inline constexpr size_t kP256_PrivateKey_Length = CHIP_CRYPTO_GROUP_SIZE_BYTES;
92 : inline constexpr size_t kP256_PublicKey_Length = CHIP_CRYPTO_PUBLIC_KEY_SIZE_BYTES;
93 :
94 : inline constexpr size_t kAES_CCM128_Key_Length = 128u / 8u;
95 : inline constexpr size_t kAES_CCM128_Block_Length = kAES_CCM128_Key_Length;
96 : inline constexpr size_t kAES_CCM128_Nonce_Length = 13;
97 : inline constexpr size_t kAES_CCM128_Tag_Length = 16;
98 : inline constexpr size_t kHMAC_CCM128_Key_Length = 128u / 8u;
99 :
100 : inline constexpr size_t CHIP_CRYPTO_AEAD_NONCE_LENGTH_BYTES = kAES_CCM128_Nonce_Length;
101 :
102 : /* These sizes are hardcoded here to remove header dependency on underlying crypto library
103 : * in a public interface file. The validity of these sizes is verified by static_assert in
104 : * the implementation files.
105 : */
106 : inline constexpr size_t kMAX_Spake2p_Context_Size = 1024;
107 : inline constexpr size_t kMAX_P256Keypair_Context_Size = 512;
108 :
109 : inline constexpr size_t kEmitDerIntegerWithoutTagOverhead = 1; // 1 sign stuffer
110 : inline constexpr size_t kEmitDerIntegerOverhead = 3; // Tag + Length byte + 1 sign stuffer
111 :
112 : inline constexpr size_t kMAX_Hash_SHA256_Context_Size = CHIP_CONFIG_SHA256_CONTEXT_SIZE;
113 :
114 : inline constexpr size_t kSpake2p_WS_Length = kP256_FE_Length + 8;
115 : inline constexpr size_t kSpake2p_VerifierSerialized_Length = kP256_FE_Length + kP256_Point_Length;
116 :
117 : inline constexpr char kVIDPrefixForCNEncoding[] = "Mvid:";
118 : inline constexpr char kPIDPrefixForCNEncoding[] = "Mpid:";
119 : inline constexpr size_t kVIDandPIDHexLength = sizeof(uint16_t) * 2;
120 : inline constexpr size_t kMax_CommonNameAttr_Length = 64;
121 :
122 : enum class FabricBindingVersion : uint8_t
123 : {
124 : kVersion1 = 0x01 // Initial version using version 1.0 of the Matter Cryptographic Primitives.
125 : };
126 :
127 : // VidVerificationStatementVersion is on purpose different and non-overlapping with FabricBindingVersion.
128 : enum class VidVerificationStatementVersion : uint8_t
129 : {
130 : kVersion1 = 0x21 // Initial version using version 1.0 of the Matter Cryptographic Primitives.
131 : };
132 :
133 : inline constexpr uint8_t kFabricBindingVersionV1 = 1u;
134 :
135 : inline constexpr size_t kVendorIdVerificationClientChallengeSize = 32u;
136 :
137 : // VIDVerificationStatement := statement_version || vid_verification_signer_skid || vid_verification_statement_signature
138 : inline constexpr size_t kVendorIdVerificationStatementV1Size =
139 : sizeof(uint8_t) + kSubjectKeyIdentifierLength + kP256_ECDSA_Signature_Length_Raw;
140 : static_assert(
141 : kVendorIdVerificationStatementV1Size == 85,
142 : "Expected size of VendorIdVerificationStatement version 1 was computed incorrectly due to changes of fundamental constants");
143 :
144 : // vendor_fabric_binding_message := fabric_binding_version (1 byte) || root_public_key || fabric_id || vendor_id
145 : inline constexpr size_t kVendorFabricBindingMessageV1Size =
146 : sizeof(uint8_t) + CHIP_CRYPTO_PUBLIC_KEY_SIZE_BYTES + sizeof(uint64_t) + sizeof(uint16_t);
147 : static_assert(
148 : kVendorFabricBindingMessageV1Size == 76,
149 : "Expected size of VendorFabricBindingMessage version 1 was computed incorrectly due to changes of fundamental constants");
150 :
151 : // vendor_id_verification_tbs := fabric_binding_version || client_challenge || attestation_challenge || fabric_index ||
152 : // vendor_fabric_binding_message || <vid_verification_statement>
153 : inline constexpr size_t kVendorIdVerificationTbsV1MaxSize = sizeof(uint8_t) + kVendorIdVerificationClientChallengeSize +
154 : CHIP_CRYPTO_SYMMETRIC_KEY_LENGTH_BYTES + sizeof(uint8_t) + kVendorFabricBindingMessageV1Size +
155 : kVendorIdVerificationStatementV1Size;
156 :
157 : /*
158 : * Overhead to encode a raw ECDSA signature in X9.62 format in ASN.1 DER
159 : *
160 : * Ecdsa-Sig-Value ::= SEQUENCE {
161 : * r INTEGER,
162 : * s INTEGER
163 : * }
164 : *
165 : * --> SEQUENCE, universal constructed tag (0x30), length over 2 bytes, up to 255 (to support future larger sizes up to 512 bits)
166 : * -> SEQ_OVERHEAD = 3 bytes
167 : * --> INTEGER, universal primitive tag (0x02), length over 1 byte, one extra byte worst case
168 : * over max for 0x00 when MSB is set.
169 : * -> INT_OVERHEAD = 3 bytes
170 : *
171 : * There is 1 sequence of 2 integers. Overhead is SEQ_OVERHEAD + (2 * INT_OVERHEAD) = 3 + (2 * 3) = 9.
172 : */
173 : inline constexpr size_t kMax_ECDSA_X9Dot62_Asn1_Overhead = 9;
174 : inline constexpr size_t kMax_ECDSA_Signature_Length_Der = kMax_ECDSA_Signature_Length + kMax_ECDSA_X9Dot62_Asn1_Overhead;
175 :
176 : static_assert(kMax_ECDH_Secret_Length >= kP256_FE_Length, "ECDH shared secret is too short for crypto suite");
177 : static_assert(kMax_ECDSA_Signature_Length >= kP256_ECDSA_Signature_Length_Raw,
178 : "ECDSA signature buffer length is too short for crypto suite");
179 :
180 : inline constexpr size_t kCompressedFabricIdentifierSize = 8;
181 :
182 : /**
183 : * Spake2+ parameters for P256
184 : * Defined in https://www.ietf.org/id/draft-bar-cfrg-spake2plus-01.html#name-ciphersuites
185 : */
186 : const uint8_t spake2p_M_p256[] = {
187 : 0x04, 0x88, 0x6e, 0x2f, 0x97, 0xac, 0xe4, 0x6e, 0x55, 0xba, 0x9d, 0xd7, 0x24, 0x25, 0x79, 0xf2, 0x99,
188 : 0x3b, 0x64, 0xe1, 0x6e, 0xf3, 0xdc, 0xab, 0x95, 0xaf, 0xd4, 0x97, 0x33, 0x3d, 0x8f, 0xa1, 0x2f, 0x5f,
189 : 0xf3, 0x55, 0x16, 0x3e, 0x43, 0xce, 0x22, 0x4e, 0x0b, 0x0e, 0x65, 0xff, 0x02, 0xac, 0x8e, 0x5c, 0x7b,
190 : 0xe0, 0x94, 0x19, 0xc7, 0x85, 0xe0, 0xca, 0x54, 0x7d, 0x55, 0xa1, 0x2e, 0x2d, 0x20,
191 : };
192 : const uint8_t spake2p_N_p256[] = {
193 : 0x04, 0xd8, 0xbb, 0xd6, 0xc6, 0x39, 0xc6, 0x29, 0x37, 0xb0, 0x4d, 0x99, 0x7f, 0x38, 0xc3, 0x77, 0x07,
194 : 0x19, 0xc6, 0x29, 0xd7, 0x01, 0x4d, 0x49, 0xa2, 0x4b, 0x4f, 0x98, 0xba, 0xa1, 0x29, 0x2b, 0x49, 0x07,
195 : 0xd6, 0x0a, 0xa6, 0xbf, 0xad, 0xe4, 0x50, 0x08, 0xa6, 0x36, 0x33, 0x7f, 0x51, 0x68, 0xc6, 0x4d, 0x9b,
196 : 0xd3, 0x60, 0x34, 0x80, 0x8c, 0xd5, 0x64, 0x49, 0x0b, 0x1e, 0x65, 0x6e, 0xdb, 0xe7,
197 : };
198 :
199 : /**
200 : * Spake2+ state machine to ensure proper execution of the protocol.
201 : */
202 : enum class CHIP_SPAKE2P_STATE : uint8_t
203 : {
204 : PREINIT = 0, // Before any initialization
205 : INIT, // First initialization
206 : STARTED, // Prover & Verifier starts
207 : R1, // Round one complete
208 : R2, // Round two complete
209 : KC, // Key confirmation complete
210 : };
211 :
212 : /**
213 : * Spake2+ role.
214 : */
215 : enum class CHIP_SPAKE2P_ROLE : uint8_t
216 : {
217 : VERIFIER = 0, // Accessory
218 : PROVER = 1, // Commissioner
219 : };
220 :
221 : enum class SupportedECPKeyTypes : uint8_t
222 : {
223 : ECP256R1 = 0,
224 : };
225 :
226 : enum class ECPKeyTarget : uint8_t
227 : {
228 : ECDH = 0,
229 : ECDSA = 1,
230 : };
231 :
232 : /** @brief Safely clears the first `len` bytes of memory area `buf`.
233 : * @param buf Pointer to a memory buffer holding secret data that must be cleared.
234 : * @param len Specifies secret data size in bytes.
235 : **/
236 : void ClearSecretData(uint8_t * buf, size_t len);
237 :
238 : /**
239 : * Helper for clearing a C array which auto-deduces the size.
240 : */
241 : template <size_t N>
242 419338 : void ClearSecretData(uint8_t (&buf)[N])
243 : {
244 419338 : ClearSecretData(buf, N);
245 419338 : }
246 :
247 : /**
248 : * @brief Constant-time buffer comparison
249 : *
250 : * This function implements constant time memcmp. It's good practice
251 : * to use constant time functions for cryptographic functions.
252 : *
253 : * @param a Pointer to first buffer
254 : * @param b Pointer to Second buffer
255 : * @param n Number of bytes to compare
256 : * @return true if `n` first bytes of both buffers are equal, false otherwise
257 : */
258 : bool IsBufferContentEqualConstantTime(const void * a, const void * b, size_t n);
259 :
260 : template <typename Sig>
261 : class ECPKey
262 : {
263 : protected:
264 : // This base type can't be copied / assigned directly.
265 : // Sub-types should be either uncopyable or final.
266 19999 : ECPKey() = default;
267 1 : ECPKey(const ECPKey &) = default;
268 1910 : ECPKey & operator=(const ECPKey &) = default;
269 :
270 : public:
271 20000 : virtual ~ECPKey() = default;
272 :
273 : virtual SupportedECPKeyTypes Type() const = 0;
274 : virtual size_t Length() const = 0;
275 : virtual bool IsUncompressed() const = 0;
276 : virtual operator const uint8_t *() const = 0;
277 : virtual operator uint8_t *() = 0;
278 : virtual const uint8_t * ConstBytes() const = 0;
279 : virtual uint8_t * Bytes() = 0;
280 :
281 954 : virtual bool Matches(const ECPKey<Sig> & other) const
282 : {
283 1908 : return (this->Length() == other.Length()) &&
284 1908 : IsBufferContentEqualConstantTime(this->ConstBytes(), other.ConstBytes(), this->Length());
285 : }
286 :
287 : virtual CHIP_ERROR ECDSA_validate_msg_signature(const uint8_t * msg, const size_t msg_length, const Sig & signature) const = 0;
288 : virtual CHIP_ERROR ECDSA_validate_hash_signature(const uint8_t * hash, const size_t hash_length,
289 : const Sig & signature) const = 0;
290 : };
291 :
292 : /**
293 : * @brief Helper class for holding sensitive data that should be erased from memory after use.
294 : *
295 : * The sensitive data buffer is a variable-length, fixed-capacity buffer class that securely erases
296 : * the contents of a buffer when the buffer is destroyed.
297 : */
298 : template <size_t kCapacity>
299 : class SensitiveDataBuffer
300 : {
301 : public:
302 7345 : ~SensitiveDataBuffer()
303 : {
304 : // Sanitize after use
305 7345 : ClearSecretData(mBytes);
306 7345 : }
307 7347 : SensitiveDataBuffer() {}
308 1 : SensitiveDataBuffer(const SensitiveDataBuffer & other) { *this = other; }
309 1 : SensitiveDataBuffer & operator=(const SensitiveDataBuffer & other)
310 : {
311 : // Guard self assignment
312 1 : if (this == &other)
313 0 : return *this;
314 :
315 1 : ClearSecretData(mBytes);
316 1 : TEMPORARY_RETURN_IGNORED SetLength(other.Length());
317 1 : ::memcpy(Bytes(), other.ConstBytes(), other.Length());
318 1 : return *this;
319 : }
320 :
321 : /**
322 : * @brief Set current length of the buffer
323 : * @return Error if new length is exceeds capacity of the buffer
324 : */
325 5601 : CHIP_ERROR SetLength(size_t length)
326 : {
327 5601 : VerifyOrReturnError(length <= kCapacity, CHIP_ERROR_INVALID_ARGUMENT);
328 5600 : mLength = length;
329 5600 : return CHIP_NO_ERROR;
330 : }
331 :
332 : /**
333 : * @brief Returns current length of the buffer
334 : */
335 6314 : size_t Length() const { return mLength; }
336 :
337 : /**
338 : * @brief Returns non-const pointer to start of the underlying buffer
339 : */
340 7997 : uint8_t * Bytes() { return &mBytes[0]; }
341 :
342 : /**
343 : * @brief Returns const pointer to start of the underlying buffer
344 : */
345 9615 : const uint8_t * ConstBytes() const { return &mBytes[0]; }
346 :
347 : /**
348 : * @brief Constructs span from the underlying buffer
349 : */
350 33 : ByteSpan Span() const { return ByteSpan(ConstBytes(), Length()); }
351 :
352 : /**
353 : * @brief Returns capacity of the buffer
354 : */
355 3195 : static constexpr size_t Capacity() { return kCapacity; }
356 :
357 : private:
358 : uint8_t mBytes[kCapacity];
359 : size_t mLength = 0;
360 : };
361 :
362 : /**
363 : * @brief Helper class for holding fixed-sized sensitive data that should be erased from memory after use.
364 : *
365 : * The sensitive data buffer is a fixed-length, fixed-capacity buffer class that securely erases
366 : * the contents of a buffer when the buffer is destroyed.
367 : */
368 : template <size_t kCapacity>
369 : class SensitiveDataFixedBuffer
370 : {
371 : public:
372 : SensitiveDataFixedBuffer() = default;
373 :
374 1 : constexpr explicit SensitiveDataFixedBuffer(const uint8_t (&rawValue)[kCapacity])
375 : {
376 1 : memcpy(&mBytes[0], &rawValue[0], kCapacity);
377 1 : }
378 :
379 2 : constexpr explicit SensitiveDataFixedBuffer(const FixedByteSpan<kCapacity> & value)
380 : {
381 2 : memcpy(&mBytes[0], value.data(), kCapacity);
382 2 : }
383 :
384 135593 : ~SensitiveDataFixedBuffer()
385 : {
386 : // Sanitize after use
387 135593 : ClearSecretData(mBytes);
388 135593 : }
389 :
390 : /**
391 : * @brief Returns fixed length of the buffer
392 : */
393 : constexpr size_t Length() const { return kCapacity; }
394 :
395 : /**
396 : * @brief Returns non-const pointer to start of the underlying buffer
397 : */
398 1791 : uint8_t * Bytes() { return &mBytes[0]; }
399 :
400 : /**
401 : * @brief Returns const pointer to start of the underlying buffer
402 : */
403 23 : const uint8_t * ConstBytes() const { return &mBytes[0]; }
404 :
405 : /**
406 : * @brief Constructs fixed span from the underlying buffer
407 : */
408 23 : FixedByteSpan<kCapacity> Span() const { return FixedByteSpan<kCapacity>(mBytes); }
409 :
410 : /**
411 : * @brief Returns capacity of the buffer
412 : */
413 1796 : static constexpr size_t Capacity() { return kCapacity; }
414 :
415 : private:
416 : uint8_t mBytes[kCapacity];
417 : };
418 :
419 : using P256ECDSASignature = SensitiveDataBuffer<kMax_ECDSA_Signature_Length>;
420 : using P256ECDHDerivedSecret = SensitiveDataBuffer<kMax_ECDH_Secret_Length>;
421 :
422 : using IdentityProtectionKey = SensitiveDataFixedBuffer<CHIP_CRYPTO_SYMMETRIC_KEY_LENGTH_BYTES>;
423 : using IdentityProtectionKeySpan = FixedByteSpan<Crypto::CHIP_CRYPTO_SYMMETRIC_KEY_LENGTH_BYTES>;
424 :
425 : using AttestationChallenge = SensitiveDataFixedBuffer<CHIP_CRYPTO_SYMMETRIC_KEY_LENGTH_BYTES>;
426 :
427 : class P256PublicKey final // final due to being copyable
428 : : public ECPKey<P256ECDSASignature>
429 : {
430 : public:
431 19004 : P256PublicKey() = default;
432 :
433 : template <size_t N>
434 5 : constexpr P256PublicKey(const uint8_t (&raw_value)[N])
435 5 : {
436 : static_assert(N == kP256_PublicKey_Length, "Can only array-initialize from proper bounds");
437 5 : memcpy(&bytes[0], &raw_value[0], N);
438 5 : }
439 :
440 : template <size_t N>
441 990 : constexpr P256PublicKey(const FixedByteSpan<N> & value)
442 990 : {
443 : static_assert(N == kP256_PublicKey_Length, "Can only initialize from proper sized byte span");
444 990 : memcpy(&bytes[0], value.data(), N);
445 990 : }
446 :
447 : template <size_t N>
448 1181 : P256PublicKey & operator=(const FixedByteSpan<N> & value)
449 : {
450 : static_assert(N == kP256_PublicKey_Length, "Can only initialize from proper sized byte span");
451 1181 : memcpy(&bytes[0], value.data(), N);
452 1181 : return *this;
453 : }
454 :
455 5367 : SupportedECPKeyTypes Type() const override { return SupportedECPKeyTypes::ECP256R1; }
456 20641 : size_t Length() const override { return kP256_PublicKey_Length; }
457 8096 : operator uint8_t *() override { return bytes; }
458 3218 : operator const uint8_t *() const override { return bytes; }
459 3893 : const uint8_t * ConstBytes() const override { return &bytes[0]; }
460 34 : uint8_t * Bytes() override { return &bytes[0]; }
461 949 : bool IsUncompressed() const override
462 : {
463 949 : constexpr uint8_t kUncompressedPointMarker = 0x04;
464 : // SEC1 definition of an uncompressed point is (0x04 || X || Y) where X and Y are
465 : // raw zero-padded big-endian large integers of the group size.
466 949 : return (Length() == ((kP256_FE_Length * 2) + 1)) && (ConstBytes()[0] == kUncompressedPointMarker);
467 : }
468 :
469 : CHIP_ERROR ECDSA_validate_msg_signature(const uint8_t * msg, size_t msg_length,
470 : const P256ECDSASignature & signature) const override;
471 : CHIP_ERROR ECDSA_validate_hash_signature(const uint8_t * hash, size_t hash_length,
472 : const P256ECDSASignature & signature) const override;
473 :
474 : private:
475 : uint8_t bytes[kP256_PublicKey_Length];
476 : };
477 :
478 : template <typename PK, typename Secret, typename Sig>
479 : class ECPKeypair
480 : {
481 : protected:
482 : // This base type can't be copied / assigned directly.
483 : // Sub-types should be either uncopyable or final.
484 2240 : ECPKeypair() = default;
485 : ECPKeypair(const ECPKeypair &) = default;
486 : ECPKeypair & operator=(const ECPKeypair &) = default;
487 :
488 : public:
489 2240 : virtual ~ECPKeypair() = default;
490 :
491 : /** @brief Generate a new Certificate Signing Request (CSR).
492 : * @param csr Newly generated CSR in DER format
493 : * @param csr_length The caller provides the length of input buffer (csr). The function returns the actual length of generated
494 : *CSR.
495 : * @return Returns a CHIP_ERROR on error, CHIP_NO_ERROR otherwise
496 : **/
497 : virtual CHIP_ERROR NewCertificateSigningRequest(uint8_t * csr, size_t & csr_length) const = 0;
498 :
499 : /**
500 : * @brief A function to sign a msg using ECDSA
501 : * @param msg Message that needs to be signed
502 : * @param msg_length Length of message
503 : * @param out_signature Buffer that will hold the output signature. The signature consists of: 2 EC elements (r and s),
504 : * in raw <r,s> point form (see SEC1).
505 : * @return Returns a CHIP_ERROR on error, CHIP_NO_ERROR otherwise
506 : **/
507 : virtual CHIP_ERROR ECDSA_sign_msg(const uint8_t * msg, size_t msg_length, Sig & out_signature) const = 0;
508 :
509 : /** @brief A function to derive a shared secret using ECDH
510 : * @param remote_public_key Public key of remote peer with which we are trying to establish secure channel. remote_public_key is
511 : * ASN.1 DER encoded as padded big-endian field elements as described in SEC 1: Elliptic Curve Cryptography
512 : * [https://www.secg.org/sec1-v2.pdf]
513 : * @param out_secret Buffer to write out secret into. This is a byte array representing the x coordinate of the shared secret.
514 : * @return Returns a CHIP_ERROR on error, CHIP_NO_ERROR otherwise
515 : **/
516 : virtual CHIP_ERROR ECDH_derive_secret(const PK & remote_public_key, Secret & out_secret) const = 0;
517 :
518 : virtual const PK & Pubkey() const = 0;
519 : };
520 :
521 : struct alignas(size_t) P256KeypairContext
522 : {
523 : uint8_t mBytes[kMAX_P256Keypair_Context_Size];
524 : };
525 :
526 : /**
527 : * A serialized P256 key pair is the concatenation of the public and private keys, in that order.
528 : */
529 : using P256SerializedKeypair = SensitiveDataBuffer<kP256_PublicKey_Length + kP256_PrivateKey_Length>;
530 :
531 : // Base class of P256Keypair. Do not use directly.
532 : class P256KeypairBase : public ECPKeypair<P256PublicKey, P256ECDHDerivedSecret, P256ECDSASignature>
533 : {
534 : protected:
535 : // This base type can't be copied / assigned directly.
536 : // Sub-types should be either uncopyable or final.
537 2240 : P256KeypairBase() = default;
538 : P256KeypairBase(const P256KeypairBase &) = default;
539 : P256KeypairBase & operator=(const P256KeypairBase &) = default;
540 :
541 : public:
542 : virtual CHIP_ERROR Initialize(ECPKeyTarget key_target) = 0;
543 : virtual CHIP_ERROR Serialize(P256SerializedKeypair & output) const = 0;
544 : virtual CHIP_ERROR Deserialize(P256SerializedKeypair & input) = 0;
545 : };
546 :
547 : /**
548 : * A platform-specific P256 keypair implementation.
549 : *
550 : * WARNING: This class does not currently define the behavior of certain sequences of operations;
551 : * depending on the platform and/or crypto backend, these sequences may work, return errors, or
552 : * have undefined behavior. Such sequences include:
553 : * - Calling any method that uses the keypair before calling a method that initializes it.
554 : * - Calling any method that uses the keypair after calling Clear()
555 : * - Calling any method that initializes, deserializes, or loads the key pair on a
556 : * keypair that has already been initialized, without an intervening call to Clear().
557 : */
558 : class P256Keypair : public P256KeypairBase
559 : {
560 : public:
561 2240 : P256Keypair() = default;
562 : ~P256Keypair() override;
563 :
564 : // P256Keypair can't be copied / assigned.
565 : P256Keypair(const P256Keypair &) = delete;
566 : P256Keypair & operator=(const P256Keypair &) = delete;
567 :
568 : /**
569 : * @brief Initializes this object by generating a new keypair.
570 : * @return Returns a CHIP_ERROR on error, CHIP_NO_ERROR otherwise
571 : **/
572 : CHIP_ERROR Initialize(ECPKeyTarget key_target) override;
573 :
574 : /**
575 : * @brief Exports the keypair as a P256SerializedKeypair containing raw public and private key bytes.
576 : * @return Returns a CHIP_ERROR on error, CHIP_NO_ERROR otherwise
577 : **/
578 : CHIP_ERROR Serialize(P256SerializedKeypair & output) const override;
579 :
580 : /**
581 : * @brief Initializes this object by importing from a P256SerializedKeypair containing raw public and private key bytes.
582 : * @return Returns a CHIP_ERROR on error, CHIP_NO_ERROR otherwise
583 : **/
584 : CHIP_ERROR Deserialize(/* const */ P256SerializedKeypair & input) override;
585 :
586 : /**
587 : * @brief Generates a new Certificate Signing Request (CSR).
588 : * @param csr Newly generated CSR in DER format
589 : * @param csr_length The caller provides the length of input buffer (csr). The function returns the actual length of generated
590 : *CSR.
591 : * @return Returns a CHIP_ERROR on error, CHIP_NO_ERROR otherwise
592 : **/
593 : CHIP_ERROR NewCertificateSigningRequest(uint8_t * csr, size_t & csr_length) const override;
594 :
595 : /**
596 : * @brief Signs a message using ECDSA
597 : * @param msg Message that needs to be signed
598 : * @param msg_length Length of message
599 : * @param out_signature Buffer that will hold the output signature. The signature consists of: 2 EC elements (r and s),
600 : * in raw <r,s> point form (see SEC1).
601 : * @return Returns a CHIP_ERROR on error, CHIP_NO_ERROR otherwise
602 : **/
603 : CHIP_ERROR ECDSA_sign_msg(const uint8_t * msg, size_t msg_length, P256ECDSASignature & out_signature) const override;
604 :
605 : /**
606 : * @brief Derives a shared secret using ECDH
607 : *
608 : * This implements the CHIP_Crypto_ECDH(PrivateKey myPrivateKey, PublicKey theirPublicKey) cryptographic primitive
609 : * from the specification, using this class's private key from `mKeypair` as `myPrivateKey` and the remote
610 : * public key from `remote_public_key` as `theirPublicKey`.
611 : *
612 : * @param remote_public_key Public key of remote peer with which we are trying to establish secure channel. remote_public_key is
613 : * ASN.1 DER encoded as padded big-endian field elements as described in SEC 1: Elliptic Curve Cryptography
614 : * [https://www.secg.org/sec1-v2.pdf]
615 : * @param out_secret Buffer to write out secret into. This is a byte array representing the x coordinate of the shared secret.
616 : * @return Returns a CHIP_ERROR on error, CHIP_NO_ERROR otherwise
617 : **/
618 : CHIP_ERROR ECDH_derive_secret(const P256PublicKey & remote_public_key, P256ECDHDerivedSecret & out_secret) const override;
619 :
620 : /**
621 : * @brief Loads a P256 keypair from raw private and public key byte spans.
622 : *
623 : * !!!!!! IMPORTANT !!!!!!!
624 : * Raw private keys SHOULD NOT be loaded directly without extreme care about ensuring they do not get retained in
625 : * memory (e.g. stack or heap) and have the shortest possible lifecycle. Please consider replacing basic example
626 : * usage of private key loading with delegation of signing to another part of the system that preferably has key
627 : * material isolation or protection.
628 : *
629 : * Combines the public and private key data into a serialized keypair format,
630 : * then deserializes it into this keypair object.
631 : *
632 : * @param private_key ByteSpan containing the raw private key bytes.
633 : * @param public_key ByteSpan containing the raw public key bytes.
634 : * @return CHIP_ERROR indicating success or failure of the operation.
635 : */
636 : CHIP_ERROR HazardousOperationLoadKeypairFromRaw(ByteSpan private_key, ByteSpan public_key);
637 :
638 : /** @brief Returns the public key for the keypair.
639 : **/
640 1413 : const P256PublicKey & Pubkey() const override { return mPublicKey; }
641 :
642 : #if CHIP_WITH_NLFAULTINJECTION
643 0 : P256PublicKey & TestOnlyMutablePubkey() { return mPublicKey; }
644 : #endif
645 :
646 : /** Release resources associated with this key pair */
647 : void Clear();
648 :
649 : protected:
650 : #if CHIP_WITH_NLFAULTINJECTION
651 : mutable P256PublicKey mPublicKey;
652 : #else
653 : P256PublicKey mPublicKey;
654 : #endif
655 : // P256PublicKey mPublicKey;
656 : mutable P256KeypairContext mKeypair;
657 : bool mInitialized = false;
658 : };
659 :
660 : /**
661 : * @brief Platform-specific symmetric key handle
662 : *
663 : * The class represents a key used by the Matter stack either in the form of raw key material or key
664 : * reference, depending on the platform. To achieve that, it contains an opaque context that can be
665 : * cast to a concrete representation used by the given platform.
666 : *
667 : * @note SymmetricKeyHandle is an abstract class to force child classes for each key handle type.
668 : * SymmetricKeyHandle class implements all the necessary components for handles.
669 : */
670 : template <size_t ContextSize>
671 : class SymmetricKeyHandle
672 : {
673 : public:
674 : SymmetricKeyHandle(const SymmetricKeyHandle &) = delete;
675 : SymmetricKeyHandle(SymmetricKeyHandle &&) = delete;
676 : void operator=(const SymmetricKeyHandle &) = delete;
677 : void operator=(SymmetricKeyHandle &&) = delete;
678 :
679 : /**
680 : * @brief Get internal context cast to the desired key representation
681 : */
682 : template <class T>
683 30718 : const T & As() const
684 : {
685 30718 : return *SafePointerCast<const T *>(&mContext);
686 : }
687 :
688 : /**
689 : * @brief Get internal context cast to the desired, mutable key representation
690 : */
691 : template <class T>
692 8588 : T & AsMutable()
693 : {
694 8588 : return *SafePointerCast<T *>(&mContext);
695 : }
696 :
697 : protected:
698 271895 : SymmetricKeyHandle() = default;
699 272060 : ~SymmetricKeyHandle() { ClearSecretData(mContext.mOpaque); }
700 :
701 : private:
702 : struct alignas(uintptr_t) OpaqueContext
703 : {
704 : uint8_t mOpaque[ContextSize] = {};
705 : } mContext;
706 : };
707 :
708 : using Symmetric128BitsKeyByteArray = uint8_t[CHIP_CRYPTO_SYMMETRIC_KEY_LENGTH_BYTES];
709 :
710 : /**
711 : * @brief Platform-specific 128-bit symmetric key handle
712 : */
713 : class Symmetric128BitsKeyHandle : public SymmetricKeyHandle<CHIP_CRYPTO_SYMMETRIC_KEY_LENGTH_BYTES>
714 : {
715 : };
716 :
717 : /**
718 : * @brief Platform-specific 128-bit AES key handle
719 : */
720 : class Aes128KeyHandle final : public Symmetric128BitsKeyHandle
721 : {
722 : };
723 :
724 : /**
725 : * @brief Platform-specific 128-bit HMAC key handle
726 : */
727 : class Hmac128KeyHandle final : public Symmetric128BitsKeyHandle
728 : {
729 : };
730 :
731 : /**
732 : * @brief Platform-specific HKDF key handle
733 : */
734 : class HkdfKeyHandle final : public SymmetricKeyHandle<CHIP_CONFIG_HKDF_KEY_HANDLE_CONTEXT_SIZE>
735 : {
736 : };
737 :
738 : /**
739 : * @brief Convert a raw ECDSA signature to ASN.1 signature (per X9.62) as used by TLS libraries.
740 : *
741 : * Errors are:
742 : * - CHIP_ERROR_INVALID_ARGUMENT on any argument being invalid (e.g. nullptr), wrong sizes,
743 : * wrong or unsupported format,
744 : * - CHIP_ERROR_BUFFER_TOO_SMALL on running out of space at runtime.
745 : * - CHIP_ERROR_INTERNAL on any unexpected processing error.
746 : *
747 : * @param[in] fe_length_bytes Field Element length in bytes (e.g. 32 for P256 curve)
748 : * @param[in] raw_sig Raw signature of <r,s> concatenated
749 : * @param[out] out_asn1_sig ASN.1 DER signature format output buffer. Size must have space for at least
750 : * kMax_ECDSA_X9Dot62_Asn1_Overhead. On CHIP_NO_ERROR, the out_asn1_sig buffer will be re-assigned
751 : * to have the correct size based on variable-length output.
752 : * @return Returns a CHIP_ERROR on error, CHIP_NO_ERROR otherwise
753 : */
754 : CHIP_ERROR EcdsaRawSignatureToAsn1(size_t fe_length_bytes, const ByteSpan & raw_sig, MutableByteSpan & out_asn1_sig);
755 :
756 : /**
757 : * @brief Convert an ASN.1 DER signature (per X9.62) as used by TLS libraries to SEC1 raw format
758 : *
759 : * Errors are:
760 : * - CHIP_ERROR_INVALID_ARGUMENT on any argument being invalid (e.g. nullptr), wrong sizes,
761 : * wrong or unsupported format,
762 : * - CHIP_ERROR_BUFFER_TOO_SMALL on running out of space at runtime.
763 : * - CHIP_ERROR_INTERNAL on any unexpected processing error.
764 : *
765 : * @param[in] fe_length_bytes Field Element length in bytes (e.g. 32 for P256 curve)
766 : * @param[in] asn1_sig ASN.1 DER signature input
767 : * @param[out] out_raw_sig Raw signature of <r,s> concatenated format output buffer. Size must be at
768 : * least >= `2 * fe_length_bytes`. On CHIP_NO_ERROR, the out_raw_sig buffer will be re-assigned
769 : * to have the correct size (2 * fe_length_bytes).
770 : * @return Returns a CHIP_ERROR on error, CHIP_NO_ERROR otherwise
771 : */
772 : CHIP_ERROR EcdsaAsn1SignatureToRaw(size_t fe_length_bytes, const ByteSpan & asn1_sig, MutableByteSpan & out_raw_sig);
773 :
774 : /**
775 : * @brief Utility to read a length field after a tag in a DER-encoded stream.
776 : * @param[in] reader Reader instance from which the input will be read
777 : * @param[out] length Length of the following element read from the stream
778 : * @return CHIP_ERROR_INVALID_ARGUMENT or CHIP_ERROR_BUFFER_TOO_SMALL on error, CHIP_NO_ERROR otherwise
779 : */
780 : CHIP_ERROR ReadDerLength(chip::Encoding::LittleEndian::Reader & reader, size_t & length);
781 :
782 : /**
783 : * @brief Utility to emit a DER-encoded INTEGER given a raw unsigned large integer
784 : * in big-endian order. The `out_der_integer` span is updated to reflect the final
785 : * variable length, including tag and length, and must have at least `kEmitDerIntegerOverhead`
786 : * extra space in addition to the `raw_integer.size()`.
787 : * @param[in] raw_integer Bytes of a large unsigned integer in big-endian, possibly including leading zeroes
788 : * @param[out] out_der_integer Buffer to receive the DER-encoded integer
789 : * @return Returns CHIP_ERROR_INVALID_ARGUMENT or CHIP_ERROR_BUFFER_TOO_SMALL on error, CHIP_NO_ERROR otherwise.
790 : */
791 : CHIP_ERROR ConvertIntegerRawToDer(const ByteSpan & raw_integer, MutableByteSpan & out_der_integer);
792 :
793 : /**
794 : * @brief Utility to emit a DER-encoded INTEGER given a raw unsigned large integer
795 : * in big-endian order. The `out_der_integer` span is updated to reflect the final
796 : * variable length, excluding tag and length, and must have at least `kEmitDerIntegerWithoutTagOverhead`
797 : * extra space in addition to the `raw_integer.size()`.
798 : * @param[in] raw_integer Bytes of a large unsigned integer in big-endian, possibly including leading zeroes
799 : * @param[out] out_der_integer Buffer to receive the DER-encoded integer
800 : * @return Returns CHIP_ERROR_INVALID_ARGUMENT or CHIP_ERROR_BUFFER_TOO_SMALL on error, CHIP_NO_ERROR otherwise.
801 : */
802 : CHIP_ERROR ConvertIntegerRawToDerWithoutTag(const ByteSpan & raw_integer, MutableByteSpan & out_der_integer);
803 :
804 : /**
805 : * @brief A function that implements AES-CCM encryption
806 : *
807 : * This implements the CHIP_Crypto_AEAD_GenerateEncrypt() cryptographic primitive
808 : * from the specification. For an empty plaintext, the user of the API can provide
809 : * an empty string, or a nullptr, and provide plaintext_length as 0. The output buffer,
810 : * ciphertext can also be an empty string, or a nullptr for this case.
811 : *
812 : * @param plaintext Plaintext to encrypt
813 : * @param plaintext_length Length of plain_text
814 : * @param aad Additional authentication data
815 : * @param aad_length Length of additional authentication data
816 : * @param key Encryption key
817 : * @param nonce Encryption nonce
818 : * @param nonce_length Length of encryption nonce
819 : * @param ciphertext Buffer to write ciphertext into. Caller must ensure this is large enough to hold the ciphertext
820 : * @param tag Buffer to write tag into. Caller must ensure this is large enough to hold the tag
821 : * @param tag_length Expected length of tag
822 : * @return Returns a CHIP_ERROR on error, CHIP_NO_ERROR otherwise
823 : * */
824 : CHIP_ERROR AES_CCM_encrypt(const uint8_t * plaintext, size_t plaintext_length, const uint8_t * aad, size_t aad_length,
825 : const Aes128KeyHandle & key, const uint8_t * nonce, size_t nonce_length, uint8_t * ciphertext,
826 : uint8_t * tag, size_t tag_length);
827 :
828 : /**
829 : * @brief A function that implements AES-CCM decryption
830 : *
831 : * This implements the CHIP_Crypto_AEAD_DecryptVerify() cryptographic primitive
832 : * from the specification. For an empty ciphertext, the user of the API can provide
833 : * an empty string, or a nullptr, and provide ciphertext_length as 0. The output buffer,
834 : * plaintext can also be an empty string, or a nullptr for this case.
835 : *
836 : * @param ciphertext Ciphertext to decrypt
837 : * @param ciphertext_length Length of ciphertext
838 : * @param aad Additional authentical data.
839 : * @param aad_length Length of additional authentication data
840 : * @param tag Tag to use to decrypt
841 : * @param tag_length Length of tag
842 : * @param key Decryption key
843 : * @param nonce Encryption nonce
844 : * @param nonce_length Length of encryption nonce
845 : * @param plaintext Buffer to write plaintext into
846 : * @return Returns a CHIP_ERROR on error, CHIP_NO_ERROR otherwise
847 : **/
848 : CHIP_ERROR AES_CCM_decrypt(const uint8_t * ciphertext, size_t ciphertext_length, const uint8_t * aad, size_t aad_length,
849 : const uint8_t * tag, size_t tag_length, const Aes128KeyHandle & key, const uint8_t * nonce,
850 : size_t nonce_length, uint8_t * plaintext);
851 :
852 : /**
853 : * @brief A function that implements AES-CTR encryption/decryption
854 : *
855 : * This implements the AES-CTR-Encrypt/Decrypt() cryptographic primitives per sections
856 : * 3.7.1 and 3.7.2 of the specification. For an empty input, the user of the API
857 : * can provide an empty string, or a nullptr, and provide input as 0.
858 : * The output buffer can also be an empty string, or a nullptr for this case.
859 : *
860 : * @param input Input text to encrypt/decrypt
861 : * @param input_length Length of ciphertext
862 : * @param key Decryption key
863 : * @param nonce Encryption nonce
864 : * @param nonce_length Length of encryption nonce
865 : * @param output Buffer to write output into
866 : * @return Returns a CHIP_ERROR on error, CHIP_NO_ERROR otherwise
867 : **/
868 : CHIP_ERROR AES_CTR_crypt(const uint8_t * input, size_t input_length, const Aes128KeyHandle & key, const uint8_t * nonce,
869 : size_t nonce_length, uint8_t * output);
870 :
871 : /**
872 : * @brief Generate a PKCS#10 CSR, usable for Matter, from a P256Keypair.
873 : *
874 : * This uses first principles ASN.1 encoding to avoid relying on the CHIPCryptoPAL backend
875 : * itself, other than to provide an implementation of a P256Keypair * that supports
876 : * at least `::Pubkey()` and `::ECDSA_sign_msg`. This allows using it with
877 : * OS/Platform-bridged private key handling, without requiring a specific
878 : * implementation of other bits like ASN.1.
879 : *
880 : * The CSR will have subject OU set to `CSA`. This is needed since omiting
881 : * subject altogether often trips CSR parsing code. The profile at the CA can
882 : * be configured to ignore CSR requested subject.
883 : *
884 : * @param keypair The key pair for which a CSR should be generated. Must not be null.
885 : * @param csr_span Span to hold the resulting CSR. Must have size at least kMIN_CSR_Buffer_Size.
886 : * Otherwise returns CHIP_ERROR_BUFFER_TOO_SMALL. It will get resized to
887 : * actual size needed on success.
888 :
889 : * @return Returns a CHIP_ERROR from P256Keypair or ASN.1 backend on error, CHIP_NO_ERROR otherwise
890 : **/
891 : CHIP_ERROR GenerateCertificateSigningRequest(const P256Keypair * keypair, MutableByteSpan & csr_span);
892 :
893 : /**
894 : * @brief Common code to validate ASN.1 format/size of a CSR, used by VerifyCertificateSigningRequest.
895 : *
896 : * Ensures it's not obviously malformed and doesn't have trailing garbage.
897 : *
898 : * @param csr CSR in DER format
899 : * @param csr_length The length of the CSR buffer
900 : * @return CHIP_ERROR_UNSUPPORTED_CERT_FORMAT on invalid format, CHIP_NO_ERROR otherwise.
901 : */
902 : CHIP_ERROR VerifyCertificateSigningRequestFormat(const uint8_t * csr, size_t csr_length);
903 :
904 : /**
905 : * @brief Verify the Certificate Signing Request (CSR). If successfully verified, it outputs the public key from the CSR.
906 : *
907 : * The CSR is valid if the format is correct, the signature validates with the embedded public
908 : * key, and there is no trailing garbage data.
909 : *
910 : * @param csr CSR in DER format
911 : * @param csr_length The length of the CSR
912 : * @param pubkey The public key from the verified CSR
913 : * @return Returns a CHIP_ERROR on error, CHIP_NO_ERROR otherwise
914 : **/
915 : CHIP_ERROR VerifyCertificateSigningRequest(const uint8_t * csr, size_t csr_length, P256PublicKey & pubkey);
916 :
917 : /**
918 : * @brief A function that implements SHA-256 hash
919 : *
920 : * This implements the CHIP_Crypto_Hash() cryptographic primitive
921 : * in the the specification.
922 : *
923 : * @param data The data to hash
924 : * @param data_length Length of the data
925 : * @param out_buffer Pointer to buffer to write output into
926 : * @return Returns a CHIP_ERROR on error, CHIP_NO_ERROR otherwise
927 : **/
928 :
929 : CHIP_ERROR Hash_SHA256(const uint8_t * data, size_t data_length, uint8_t * out_buffer);
930 :
931 : /**
932 : * @brief A function that implements SHA-1 hash
933 : * @param data The data to hash
934 : * @param data_length Length of the data
935 : * @param out_buffer Pointer to buffer to write output into
936 : * @return Returns a CHIP_ERROR on error, CHIP_NO_ERROR otherwise
937 : **/
938 :
939 : CHIP_ERROR Hash_SHA1(const uint8_t * data, size_t data_length, uint8_t * out_buffer);
940 :
941 : /**
942 : * @brief A class that defines stream based implementation of SHA-256 hash
943 : * It's expected that the object of this class can be safely copied.
944 : * All implementations must check for std::is_trivially_copyable.
945 : **/
946 :
947 : struct alignas(CHIP_CONFIG_SHA256_CONTEXT_ALIGN) HashSHA256OpaqueContext
948 : {
949 : uint8_t mOpaque[kMAX_Hash_SHA256_Context_Size];
950 : };
951 :
952 : class Hash_SHA256_stream
953 : {
954 : public:
955 : Hash_SHA256_stream();
956 : ~Hash_SHA256_stream();
957 :
958 : /**
959 : * @brief Re-initialize digest computation to an empty context.
960 : *
961 : * @return CHIP_ERROR_INTERNAL on failure to initialize the context,
962 : * CHIP_NO_ERROR otherwise.
963 : */
964 : CHIP_ERROR Begin();
965 :
966 : /**
967 : * @brief Add some data to the digest computation, updating internal state.
968 : *
969 : * @param[in] data The span of bytes to include in the digest update process.
970 : *
971 : * @return CHIP_ERROR_INTERNAL on failure to ingest the data, CHIP_NO_ERROR otherwise.
972 : */
973 : CHIP_ERROR AddData(const ByteSpan data);
974 :
975 : /**
976 : * @brief Get the intermediate padded digest for the current state of the stream.
977 : *
978 : * More data can be added before finish is called.
979 : *
980 : * @param[in,out] out_buffer Output buffer to receive the digest. `out_buffer` must
981 : * be at least `kSHA256_Hash_Length` bytes long. The `out_buffer` size
982 : * will be set to `kSHA256_Hash_Length` on success.
983 : *
984 : * @return CHIP_ERROR_INTERNAL on failure to compute the digest, CHIP_ERROR_BUFFER_TOO_SMALL
985 : * if out_buffer is too small, CHIP_NO_ERROR otherwise.
986 : */
987 : CHIP_ERROR GetDigest(MutableByteSpan & out_buffer);
988 :
989 : /**
990 : * @brief Finalize the stream digest computation, getting the final digest.
991 : *
992 : * @param[in,out] out_buffer Output buffer to receive the digest. `out_buffer` must
993 : * be at least `kSHA256_Hash_Length` bytes long. The `out_buffer` size
994 : * will be set to `kSHA256_Hash_Length` on success.
995 : *
996 : * @return CHIP_ERROR_INTERNAL on failure to compute the digest, CHIP_ERROR_BUFFER_TOO_SMALL
997 : * if out_buffer is too small, CHIP_NO_ERROR otherwise.
998 : */
999 : CHIP_ERROR Finish(MutableByteSpan & out_buffer);
1000 :
1001 : /**
1002 : * @brief Clear-out internal digest data to avoid lingering the state.
1003 : */
1004 : void Clear();
1005 :
1006 : private:
1007 : // Check if the digest computation has been initialized; implement this if your backend needs it.
1008 : bool IsInitialized();
1009 :
1010 : HashSHA256OpaqueContext mContext;
1011 : };
1012 :
1013 : class HKDF_sha
1014 : {
1015 : public:
1016 : HKDF_sha() = default;
1017 5988 : virtual ~HKDF_sha() = default;
1018 :
1019 : /**
1020 : * @brief A function that implements SHA-256 based HKDF
1021 : *
1022 : * This implements the CHIP_Crypto_KDF() cryptographic primitive
1023 : * in the the specification.
1024 : *
1025 : * Error values are:
1026 : * - CHIP_ERROR_INVALID_ARGUMENT: for any bad arguments or nullptr input on
1027 : * any pointer.
1028 : * - CHIP_ERROR_INTERNAL: for any unexpected error arising in the underlying
1029 : * cryptographic layers.
1030 : *
1031 : * @param secret The secret to use as the key to the HKDF
1032 : * @param secret_length Length of the secret
1033 : * @param salt Optional salt to use as input to the HKDF
1034 : * @param salt_length Length of the salt
1035 : * @param info Optional info to use as input to the HKDF
1036 : * @param info_length Length of the info
1037 : * @param out_buffer Pointer to buffer to write output into.
1038 : * @param out_length Size of the underlying out_buffer. That length of output key material will be generated in out_buffer.
1039 : * @return Returns a CHIP_ERROR on error, CHIP_NO_ERROR otherwise
1040 : **/
1041 :
1042 : virtual CHIP_ERROR HKDF_SHA256(const uint8_t * secret, size_t secret_length, const uint8_t * salt, size_t salt_length,
1043 : const uint8_t * info, size_t info_length, uint8_t * out_buffer, size_t out_length);
1044 : };
1045 :
1046 : class HMAC_sha
1047 : {
1048 : public:
1049 : HMAC_sha() = default;
1050 132 : virtual ~HMAC_sha() = default;
1051 :
1052 : /**
1053 : * @brief A function that implements SHA-256 based HMAC per FIPS1981.
1054 : *
1055 : * This implements the CHIP_Crypto_HMAC() cryptographic primitive
1056 : * in the the specification.
1057 : *
1058 : * The `out_length` must be at least kSHA256_Hash_Length, and only
1059 : * kSHA256_Hash_Length bytes are written to out_buffer.
1060 : *
1061 : * Error values are:
1062 : * - CHIP_ERROR_INVALID_ARGUMENT: for any bad arguments or nullptr input on
1063 : * any pointer.
1064 : * - CHIP_ERROR_INTERNAL: for any unexpected error arising in the underlying
1065 : * cryptographic layers.
1066 : *
1067 : * @param key The key to use for the HMAC operation
1068 : * @param key_length Length of the key
1069 : * @param message Message over which to compute the HMAC
1070 : * @param message_length Length of the message over which to compute the HMAC
1071 : * @param out_buffer Pointer to buffer into which to write the output.
1072 : * @param out_length Underlying size of the `out_buffer`.
1073 : * @return Returns a CHIP_ERROR on error, CHIP_NO_ERROR otherwise
1074 : **/
1075 :
1076 : virtual CHIP_ERROR HMAC_SHA256(const uint8_t * key, size_t key_length, const uint8_t * message, size_t message_length,
1077 : uint8_t * out_buffer, size_t out_length);
1078 :
1079 : /**
1080 : * @brief A function that implements SHA-256 based HMAC per FIPS1981.
1081 : *
1082 : * This implements the CHIP_Crypto_HMAC() cryptographic primitive
1083 : * in the the specification.
1084 : *
1085 : * The `out_length` must be at least kSHA256_Hash_Length, and only
1086 : * kSHA256_Hash_Length bytes are written to out_buffer.
1087 : *
1088 : * Error values are:
1089 : * - CHIP_ERROR_INVALID_ARGUMENT: for any bad arguments or nullptr input on
1090 : * any pointer.
1091 : * - CHIP_ERROR_INTERNAL: for any unexpected error arising in the underlying
1092 : * cryptographic layers.
1093 : *
1094 : * @param key The HMAC Key handle to use for the HMAC operation
1095 : * @param message Message over which to compute the HMAC
1096 : * @param message_length Length of the message over which to compute the HMAC
1097 : * @param out_buffer Pointer to buffer into which to write the output.
1098 : * @param out_length Underlying size of the `out_buffer`.
1099 : * @return Returns a CHIP_ERROR on error, CHIP_NO_ERROR otherwise
1100 : **/
1101 : virtual CHIP_ERROR HMAC_SHA256(const Hmac128KeyHandle & key, const uint8_t * message, size_t message_length,
1102 : uint8_t * out_buffer, size_t out_length);
1103 : };
1104 :
1105 : /**
1106 : * @brief A cryptographically secure random number generator based on NIST SP800-90A
1107 : * @param out_buffer Buffer into which to write random bytes
1108 : * @param out_length Number of random bytes to generate
1109 : * @return Returns a CHIP_ERROR on error, CHIP_NO_ERROR otherwise
1110 : **/
1111 : CHIP_ERROR DRBG_get_bytes(uint8_t * out_buffer, size_t out_length);
1112 :
1113 : /** @brief Entropy callback function
1114 : * @param data Callback-specific data pointer
1115 : * @param output Output data to fill
1116 : * @param len Length of output buffer
1117 : * @param olen The actual amount of data that was written to output buffer
1118 : * @return 0 if success
1119 : */
1120 : typedef int (*entropy_source)(void * data, uint8_t * output, size_t len, size_t * olen);
1121 :
1122 : /** @brief A function to add entropy sources to crypto library
1123 : *
1124 : * This function can be called multiple times to add multiple entropy sources. However,
1125 : * once the entropy source is added, it cannot be removed. Please make sure that the
1126 : * entropy source is valid for the lifetime of the application. Also, make sure that the
1127 : * same entropy source is not added multiple times, e.g.: by calling this function
1128 : * in class constructor or initialization function.
1129 : *
1130 : * @param fn_source Function pointer to the entropy source
1131 : * @param p_source Data that should be provided when fn_source is called
1132 : * @param threshold Minimum required from source before entropy is released
1133 : * @return Returns a CHIP_ERROR on error, CHIP_NO_ERROR otherwise
1134 : **/
1135 : CHIP_ERROR add_entropy_source(entropy_source fn_source, void * p_source, size_t threshold);
1136 :
1137 : class PBKDF2_sha256
1138 : {
1139 : public:
1140 : PBKDF2_sha256() = default;
1141 12 : virtual ~PBKDF2_sha256() = default;
1142 :
1143 : /** @brief Function to derive key using password. SHA256 hashing algorithm is used for calculating hmac.
1144 : * @param password password used for key derivation
1145 : * @param plen length of buffer containing password
1146 : * @param salt salt to use as input to the KDF
1147 : * @param slen length of salt
1148 : * @param iteration_count number of iterations to run
1149 : * @param key_length length of output key
1150 : * @param output output buffer where the key will be written
1151 : * @return Returns a CHIP_ERROR on error, CHIP_NO_ERROR otherwise
1152 : **/
1153 : virtual CHIP_ERROR pbkdf2_sha256(const uint8_t * password, size_t plen, const uint8_t * salt, size_t slen,
1154 : unsigned int iteration_count, uint32_t key_length, uint8_t * output);
1155 : };
1156 :
1157 : // TODO: Extract Spake2p to a separate header and replace the forward declaration with #include SessionKeystore.h
1158 : class SessionKeystore;
1159 :
1160 : /**
1161 : * The below class implements the draft 01 version of the Spake2+ protocol as
1162 : * defined in https://www.ietf.org/id/draft-bar-cfrg-spake2plus-01.html.
1163 : *
1164 : * The following describes the protocol flows:
1165 : *
1166 : * Commissioner Accessory
1167 : * ------------ ---------
1168 : *
1169 : * Init
1170 : * BeginProver
1171 : * ComputeRoundOne ------------->
1172 : * Init
1173 : * BeginVerifier
1174 : * /- ComputeRoundOne
1175 : * <------------- ComputeRoundTwo
1176 : * ComputeRoundTwo ------------->
1177 : * KeyConfirm KeyConfirm
1178 : * GetKeys GetKeys
1179 : *
1180 : **/
1181 : class Spake2p
1182 : {
1183 : public:
1184 : Spake2p(size_t fe_size, size_t point_size, size_t hash_size);
1185 226 : virtual ~Spake2p() = default;
1186 :
1187 : /**
1188 : * @brief Initialize Spake2+ with some context specific information.
1189 : *
1190 : * @param context The context is arbitrary but should include information about the
1191 : * protocol being run, contain the transcript for negotiation, include
1192 : * the PKBDF parameters, etc.
1193 : * @param context_len The length of the context.
1194 : *
1195 : * @return Returns a CHIP_ERROR on error, CHIP_NO_ERROR otherwise
1196 : **/
1197 : virtual CHIP_ERROR Init(const uint8_t * context, size_t context_len);
1198 :
1199 : /**
1200 : * @brief Free Spake2+ underlying objects.
1201 : **/
1202 : virtual void Clear() = 0;
1203 :
1204 : /**
1205 : * @brief Start the Spake2+ process as a verifier (i.e. an accessory being provisioned).
1206 : *
1207 : * @param my_identity The verifier identity. May be NULL if identities are not established.
1208 : * @param my_identity_len The verifier identity length.
1209 : * @param peer_identity The peer identity. May be NULL if identities are not established.
1210 : * @param peer_identity_len The peer identity length.
1211 : * @param w0in The input w0 (a parameter baked into the device or computed with ComputeW0).
1212 : * @param w0in_len The input w0 length.
1213 : * @param Lin The input L (a parameter baked into the device or computed with ComputeL).
1214 : * @param Lin_len The input L length.
1215 : *
1216 : * @return Returns a CHIP_ERROR on error, CHIP_NO_ERROR otherwise
1217 : **/
1218 : virtual CHIP_ERROR BeginVerifier(const uint8_t * my_identity, size_t my_identity_len, const uint8_t * peer_identity,
1219 : size_t peer_identity_len, const uint8_t * w0in, size_t w0in_len, const uint8_t * Lin,
1220 : size_t Lin_len);
1221 :
1222 : /**
1223 : * @brief Start the Spake2+ process as a prover (i.e. a commissioner).
1224 : *
1225 : * @param my_identity The prover identity. May be NULL if identities are not established.
1226 : * @param my_identity_len The prover identity length.
1227 : * @param peer_identity The peer identity. May be NULL if identities are not established.
1228 : * @param peer_identity_len The peer identity length.
1229 : * @param w0sin The input w0s (an output from the PBKDF).
1230 : * @param w0sin_len The input w0s length.
1231 : * @param w1sin The input w1s (an output from the PBKDF).
1232 : * @param w1sin_len The input w1s length.
1233 : *
1234 : * @return Returns a CHIP_ERROR on error, CHIP_NO_ERROR otherwise
1235 : **/
1236 : virtual CHIP_ERROR BeginProver(const uint8_t * my_identity, size_t my_identity_len, const uint8_t * peer_identity,
1237 : size_t peer_identity_len, const uint8_t * w0sin, size_t w0sin_len, const uint8_t * w1sin,
1238 : size_t w1sin_len);
1239 :
1240 : /**
1241 : * @brief Compute the first round of the protocol.
1242 : *
1243 : * @param pab X value from commissioner.
1244 : * @param pab_len X length.
1245 : * @param out The output first round Spake2+ contribution.
1246 : * @param out_len The output first round Spake2+ contribution length.
1247 : *
1248 : * @return Returns a CHIP_ERROR on error, CHIP_NO_ERROR otherwise
1249 : **/
1250 : virtual CHIP_ERROR ComputeRoundOne(const uint8_t * pab, size_t pab_len, uint8_t * out, size_t * out_len);
1251 :
1252 : /**
1253 : * @brief Compute the second round of the protocol.
1254 : *
1255 : * @param in The peer first round Spake2+ contribution.
1256 : * @param in_len The peer first round Spake2+ contribution length.
1257 : * @param out The output second round Spake2+ contribution.
1258 : * @param out_len The output second round Spake2+ contribution length.
1259 : *
1260 : * @return Returns a CHIP_ERROR on error, CHIP_NO_ERROR otherwise
1261 : **/
1262 : virtual CHIP_ERROR ComputeRoundTwo(const uint8_t * in, size_t in_len, uint8_t * out, size_t * out_len);
1263 :
1264 : /**
1265 : * @brief Confirm that each party computed the same keys.
1266 : *
1267 : * @param in The peer second round Spake2+ contribution.
1268 : * @param in_len The peer second round Spake2+ contribution length.
1269 : *
1270 : * @return Returns a CHIP_ERROR on error, CHIP_NO_ERROR otherwise
1271 : **/
1272 : virtual CHIP_ERROR KeyConfirm(const uint8_t * in, size_t in_len);
1273 :
1274 : /**
1275 : * @brief Return the shared HKDF key.
1276 : *
1277 : * Returns the shared key established during the Spake2+ process, which can be used
1278 : * to derive application-specific keys using HKDF.
1279 : *
1280 : * @param keystore The session keystore for managing the HKDF key lifetime.
1281 : * @param key The output HKDF key.
1282 : *
1283 : * @return Returns a CHIP_ERROR on error, CHIP_NO_ERROR otherwise
1284 : **/
1285 : CHIP_ERROR GetKeys(SessionKeystore & keystore, HkdfKeyHandle & key);
1286 :
1287 : CHIP_ERROR InternalHash(const uint8_t * in, size_t in_len);
1288 : CHIP_ERROR WriteMN();
1289 : CHIP_ERROR GenerateKeys();
1290 :
1291 : /**
1292 : * @brief Load a field element.
1293 : *
1294 : * @param in The input big endian field element.
1295 : * @param in_len The size of the input buffer in bytes.
1296 : * @param fe A pointer to an initialized implementation dependant field element.
1297 : *
1298 : * @return Returns a CHIP_ERROR on error, CHIP_NO_ERROR otherwise
1299 : **/
1300 : virtual CHIP_ERROR FELoad(const uint8_t * in, size_t in_len, void * fe) = 0;
1301 :
1302 : /**
1303 : * @brief Write a field element in big-endian format.
1304 : *
1305 : * @param fe The field element to write.
1306 : * @param out The output buffer.
1307 : * @param out_len The length of the output buffer.
1308 : *
1309 : * @return Returns a CHIP_ERROR on error, CHIP_NO_ERROR otherwise
1310 : **/
1311 : virtual CHIP_ERROR FEWrite(const void * fe, uint8_t * out, size_t out_len) = 0;
1312 :
1313 : /**
1314 : * @brief Generate a field element.
1315 : *
1316 : * @param fe A pointer to an initialized implementation dependant field element.
1317 : *
1318 : * @note The implementation must generate a random element from [0, q) where q is the curve order.
1319 : *
1320 : * @return Returns a CHIP_ERROR on error, CHIP_NO_ERROR otherwise
1321 : **/
1322 : virtual CHIP_ERROR FEGenerate(void * fe) = 0;
1323 :
1324 : /**
1325 : * @brief Multiply two field elements, fer = fe1 * fe2.
1326 : *
1327 : * @param fer A pointer to an initialized implementation dependant field element.
1328 : * @param fe1 A pointer to an initialized implementation dependant field element.
1329 : * @param fe2 A pointer to an initialized implementation dependant field element.
1330 : *
1331 : * @note The result must be a field element (i.e. reduced by the curve order).
1332 : *
1333 : * @return Returns a CHIP_ERROR on error, CHIP_NO_ERROR otherwise
1334 : **/
1335 : virtual CHIP_ERROR FEMul(void * fer, const void * fe1, const void * fe2) = 0;
1336 :
1337 : /**
1338 : * @brief Load a point from 0x04 || X || Y format
1339 : *
1340 : * @param in Input buffer
1341 : * @param in_len Input buffer length
1342 : * @param R A pointer to an initialized implementation dependant point.
1343 : *
1344 : * @return Returns a CHIP_ERROR on error, CHIP_NO_ERROR otherwise
1345 : **/
1346 : virtual CHIP_ERROR PointLoad(const uint8_t * in, size_t in_len, void * R) = 0;
1347 :
1348 : /**
1349 : * @brief Write a point in 0x04 || X || Y format
1350 : *
1351 : * @param R A pointer to an initialized implementation dependant point.
1352 : * @param out Output buffer
1353 : * @param out_len Length of the output buffer
1354 : *
1355 : * @return Returns a CHIP_ERROR on error, CHIP_NO_ERROR otherwise
1356 : **/
1357 : virtual CHIP_ERROR PointWrite(const void * R, uint8_t * out, size_t out_len) = 0;
1358 :
1359 : /**
1360 : * @brief Scalar multiplication, R = fe1 * P1.
1361 : *
1362 : * @param R Resultant point
1363 : * @param P1 Input point
1364 : * @param fe1 Input field element.
1365 : *
1366 : * @return Returns a CHIP_ERROR on error, CHIP_NO_ERROR otherwise
1367 : **/
1368 : virtual CHIP_ERROR PointMul(void * R, const void * P1, const void * fe1) = 0;
1369 :
1370 : /**
1371 : * @brief Scalar multiplication with addition, R = fe1 * P1 + fe2 * P2.
1372 : *
1373 : * @param R Resultant point
1374 : * @param P1 Input point
1375 : * @param fe1 Input field element.
1376 : * @param P2 Input point
1377 : * @param fe2 Input field element.
1378 : *
1379 : * @return Returns a CHIP_ERROR on error, CHIP_NO_ERROR otherwise
1380 : **/
1381 : virtual CHIP_ERROR PointAddMul(void * R, const void * P1, const void * fe1, const void * P2, const void * fe2) = 0;
1382 :
1383 : /**
1384 : * @brief Point inversion.
1385 : *
1386 : * @param R Input/Output point to point_invert
1387 : *
1388 : * @return Returns a CHIP_ERROR on error, CHIP_NO_ERROR otherwise
1389 : **/
1390 : virtual CHIP_ERROR PointInvert(void * R) = 0;
1391 :
1392 : /**
1393 : * @brief Multiply a point by the curve cofactor.
1394 : *
1395 : * @param R Input/Output point to point_invert
1396 : *
1397 : * @return Returns a CHIP_ERROR on error, CHIP_NO_ERROR otherwise
1398 : **/
1399 : virtual CHIP_ERROR PointCofactorMul(void * R) = 0;
1400 :
1401 : /*
1402 : * @synopsis Check if a point is on the curve.
1403 : *
1404 : * @param R Input point to check.
1405 : *
1406 : * @return CHIP_NO_ERROR if the point is valid, CHIP_ERROR otherwise.
1407 : */
1408 : virtual CHIP_ERROR PointIsValid(void * R) = 0;
1409 :
1410 : /*
1411 : * @synopsis Compute w0sin mod p
1412 : *
1413 : * @param w0out Output field element w0
1414 : * @param w0_len Output field element length
1415 : * @param w0sin Input field element
1416 : * @param w0sin_len Input field element length
1417 : *
1418 : * @return Returns a CHIP_ERROR on error, CHIP_NO_ERROR otherwise
1419 : **/
1420 : virtual CHIP_ERROR ComputeW0(uint8_t * w0out, size_t * w0_len, const uint8_t * w0sin, size_t w0sin_len) = 0;
1421 :
1422 : /*
1423 : * @synopsis Compute w1in*G where w1in is w1sin mod p
1424 : *
1425 : * @param Lout Output point in 0x04 || X || Y format.
1426 : * @param L_len Output point length
1427 : * @param w1sin Input field element
1428 : * @param w1sin_len Input field element size
1429 : *
1430 : * @return Returns a CHIP_ERROR on error, CHIP_NO_ERROR otherwise
1431 : **/
1432 : virtual CHIP_ERROR ComputeL(uint8_t * Lout, size_t * L_len, const uint8_t * w1sin, size_t w1sin_len) = 0;
1433 :
1434 : void * M;
1435 : void * N;
1436 : const void * G;
1437 : void * X;
1438 : void * Y;
1439 : void * L;
1440 : void * Z;
1441 : void * V;
1442 : void * w0;
1443 : void * w1;
1444 : void * xy;
1445 : void * order;
1446 : void * tempbn;
1447 :
1448 : protected:
1449 : /**
1450 : * @brief Initialize underlying implementation curve, points, field elements, etc.
1451 : *
1452 : * @details The implementation needs to:
1453 : * 1. Initialize each of the points below and set the relevant pointers on the class:
1454 : * a. M
1455 : * b. N
1456 : * c. G
1457 : * d. X
1458 : * e. Y
1459 : * f. L
1460 : * g. Z
1461 : * h. V
1462 : *
1463 : * As an example:
1464 : * this.M = implementation_alloc_point();
1465 : * 2. Initialize each of the field elements below and set the relevant pointers on the class:
1466 : * a. w0
1467 : * b. w1
1468 : * c. xy
1469 : * d. tempbn
1470 : * 3. The hashing context should be initialized
1471 : *
1472 : * @return Returns a CHIP_ERROR on error, CHIP_NO_ERROR otherwise
1473 : **/
1474 : virtual CHIP_ERROR InitImpl() = 0;
1475 :
1476 : /**
1477 : * @brief Hash in_len bytes of in into the internal hash context.
1478 : *
1479 : * @param in The input buffer.
1480 : * @param in_len Size of the input buffer in bytes.
1481 : *
1482 : * @return Returns a CHIP_ERROR on error, CHIP_NO_ERROR otherwise
1483 : **/
1484 : virtual CHIP_ERROR Hash(const uint8_t * in, size_t in_len) = 0;
1485 :
1486 : /**
1487 : * @brief Return the hash.
1488 : *
1489 : * @param out_span Output buffer. The size available must be >= the hash size. It gets resized
1490 : * to hash size on success.
1491 : *
1492 : * @return Returns a CHIP_ERROR on error, CHIP_NO_ERROR otherwise
1493 : **/
1494 : virtual CHIP_ERROR HashFinalize(MutableByteSpan & out_span) = 0;
1495 :
1496 : /**
1497 : * @brief Generate a message authentication code.
1498 : *
1499 : * @param key The MAC key buffer.
1500 : * @param key_len The size of the MAC key in bytes.
1501 : * @param in The input buffer.
1502 : * @param in_len The size of the input data to MAC in bytes.
1503 : * @param out_span The output MAC buffer span. Size must be >= the hash_size. Output size is updated to fit on success.
1504 : *
1505 : * @return Returns a CHIP_ERROR on error, CHIP_NO_ERROR otherwise
1506 : **/
1507 : virtual CHIP_ERROR Mac(const uint8_t * key, size_t key_len, const uint8_t * in, size_t in_len, MutableByteSpan & out_span) = 0;
1508 :
1509 : /**
1510 : * @brief Verify a message authentication code.
1511 : *
1512 : * @param key The MAC key buffer.
1513 : * @param key_len The size of the MAC key in bytes.
1514 : * @param mac The input MAC buffer.
1515 : * @param mac_len The size of the MAC in bytes.
1516 : * @param in The input buffer to verify.
1517 : * @param in_len The size of the input data to verify in bytes.
1518 : *
1519 : * @return Returns a CHIP_ERROR when the MAC doesn't validate, CHIP_NO_ERROR otherwise.
1520 : **/
1521 : virtual CHIP_ERROR MacVerify(const uint8_t * key, size_t key_len, const uint8_t * mac, size_t mac_len, const uint8_t * in,
1522 : size_t in_len) = 0;
1523 :
1524 : /**
1525 : * @brief Derive an key of length out_len.
1526 : *
1527 : * @param ikm The input key material buffer.
1528 : * @param ikm_len The input key material length.
1529 : * @param salt The optional salt. This may be NULL.
1530 : * @param salt_len The size of the salt in bytes.
1531 : * @param info The info.
1532 : * @param info_len The size of the info in bytes.
1533 : * @param out The output key
1534 : * @param out_len The output key length
1535 : *
1536 : * @return Returns a CHIP_ERROR when the MAC doesn't validate, CHIP_NO_ERROR otherwise.
1537 : **/
1538 : virtual CHIP_ERROR KDF(const uint8_t * ikm, size_t ikm_len, const uint8_t * salt, size_t salt_len, const uint8_t * info,
1539 : size_t info_len, uint8_t * out, size_t out_len) = 0;
1540 :
1541 : CHIP_SPAKE2P_ROLE role;
1542 : CHIP_SPAKE2P_STATE state = CHIP_SPAKE2P_STATE::PREINIT;
1543 : size_t fe_size;
1544 : size_t hash_size;
1545 : size_t point_size;
1546 : uint8_t Kcab[kMAX_Hash_Length];
1547 : uint8_t Kae[kMAX_Hash_Length];
1548 : uint8_t * Kca;
1549 : uint8_t * Kcb;
1550 : uint8_t * Ka;
1551 : uint8_t * Ke;
1552 : };
1553 :
1554 : struct alignas(size_t) Spake2pOpaqueContext
1555 : {
1556 : uint8_t mOpaque[kMAX_Spake2p_Context_Size];
1557 : };
1558 :
1559 : class Spake2p_P256_SHA256_HKDF_HMAC : public Spake2p
1560 : {
1561 : public:
1562 226 : Spake2p_P256_SHA256_HKDF_HMAC() : Spake2p(kP256_FE_Length, kP256_Point_Length, kSHA256_Hash_Length)
1563 : {
1564 226 : memset(&mSpake2pContext, 0, sizeof(mSpake2pContext));
1565 226 : }
1566 :
1567 226 : ~Spake2p_P256_SHA256_HKDF_HMAC() override { Spake2p_P256_SHA256_HKDF_HMAC::Clear(); }
1568 :
1569 : void Clear() override;
1570 : CHIP_ERROR Mac(const uint8_t * key, size_t key_len, const uint8_t * in, size_t in_len, MutableByteSpan & out_span) override;
1571 : CHIP_ERROR MacVerify(const uint8_t * key, size_t key_len, const uint8_t * mac, size_t mac_len, const uint8_t * in,
1572 : size_t in_len) override;
1573 : CHIP_ERROR FELoad(const uint8_t * in, size_t in_len, void * fe) override;
1574 : CHIP_ERROR FEWrite(const void * fe, uint8_t * out, size_t out_len) override;
1575 : CHIP_ERROR FEGenerate(void * fe) override;
1576 : CHIP_ERROR FEMul(void * fer, const void * fe1, const void * fe2) override;
1577 :
1578 : CHIP_ERROR PointLoad(const uint8_t * in, size_t in_len, void * R) override;
1579 : CHIP_ERROR PointWrite(const void * R, uint8_t * out, size_t out_len) override;
1580 : CHIP_ERROR PointMul(void * R, const void * P1, const void * fe1) override;
1581 : CHIP_ERROR PointAddMul(void * R, const void * P1, const void * fe1, const void * P2, const void * fe2) override;
1582 : CHIP_ERROR PointInvert(void * R) override;
1583 : CHIP_ERROR PointCofactorMul(void * R) override;
1584 : CHIP_ERROR PointIsValid(void * R) override;
1585 :
1586 : CHIP_ERROR ComputeW0(uint8_t * w0out, size_t * w0_len, const uint8_t * w0sin, size_t w0sin_len) override;
1587 : CHIP_ERROR ComputeL(uint8_t * Lout, size_t * L_len, const uint8_t * w1sin, size_t w1sin_len) override;
1588 :
1589 : protected:
1590 : CHIP_ERROR InitImpl() override;
1591 : CHIP_ERROR Hash(const uint8_t * in, size_t in_len) override;
1592 : CHIP_ERROR HashFinalize(MutableByteSpan & out_span) override;
1593 : CHIP_ERROR KDF(const uint8_t * secret, size_t secret_length, const uint8_t * salt, size_t salt_length, const uint8_t * info,
1594 : size_t info_length, uint8_t * out, size_t out_length) override;
1595 :
1596 : private:
1597 : CHIP_ERROR InitInternal();
1598 : Hash_SHA256_stream sha256_hash_ctx;
1599 :
1600 : Spake2pOpaqueContext mSpake2pContext;
1601 : };
1602 :
1603 : /**
1604 : * @brief Class used for verifying PASE secure sessions.
1605 : **/
1606 : class Spake2pVerifier
1607 : {
1608 : public:
1609 : uint8_t mW0[kP256_FE_Length];
1610 : uint8_t mL[kP256_Point_Length];
1611 :
1612 : CHIP_ERROR Serialize(MutableByteSpan & outSerialized) const;
1613 : CHIP_ERROR Deserialize(const ByteSpan & inSerialized);
1614 :
1615 : /**
1616 : * @brief Generate the Spake2+ verifier.
1617 : *
1618 : * @param pbkdf2IterCount Iteration count for PBKDF2 function
1619 : * @param salt Salt to be used for Spake2+ operation
1620 : * @param setupPin Provided setup PIN (passcode)
1621 : *
1622 : * @return CHIP_ERROR The result of Spake2+ verifier generation
1623 : */
1624 : CHIP_ERROR Generate(uint32_t pbkdf2IterCount, const ByteSpan & salt, uint32_t setupPin);
1625 :
1626 : /**
1627 : * @brief Compute the initiator values (w0s, w1s) used for PAKE input.
1628 : *
1629 : * @param pbkdf2IterCount Iteration count for PBKDF2 function
1630 : * @param salt Salt to be used for Spake2+ operation
1631 : * @param setupPin Provided setup PIN (passcode)
1632 : * @param ws The output pair (w0s, w1s) stored sequentially
1633 : * @param ws_len The output length
1634 : *
1635 : * @return CHIP_ERROR The result from running PBKDF2
1636 : */
1637 : static CHIP_ERROR ComputeWS(uint32_t pbkdf2IterCount, const ByteSpan & salt, uint32_t setupPin, uint8_t * ws, uint32_t ws_len);
1638 : };
1639 :
1640 : /**
1641 : * @brief Serialized format of the Spake2+ Verifier components.
1642 : *
1643 : * This is used when the Verifier should be presented in a serialized form.
1644 : * For example, when it is generated using PBKDF function, when stored in the
1645 : * memory or when sent over the wire.
1646 : * The serialized format is concatentation of 'W0' and 'L' verifier components:
1647 : * { Spake2pVerifier.mW0[kP256_FE_Length], Spake2pVerifier.mL[kP256_Point_Length] }
1648 : **/
1649 : typedef uint8_t Spake2pVerifierSerialized[kSpake2p_VerifierSerialized_Length];
1650 :
1651 : /**
1652 : * @brief Compute the compressed fabric identifier used for operational discovery service
1653 : * records from a Node's root public key and Fabric ID. On success, out_compressed_fabric_id
1654 : * will have a size of exactly kCompressedFabricIdentifierSize.
1655 : *
1656 : * Errors are:
1657 : * - CHIP_ERROR_INVALID_ARGUMENT if root_public_key is invalid
1658 : * - CHIP_ERROR_BUFFER_TOO_SMALL if out_compressed_fabric_id is too small for serialization
1659 : * - CHIP_ERROR_INTERNAL on any unexpected crypto or data conversion errors.
1660 : *
1661 : * @param[in] root_public_key The root public key associated with the node's fabric
1662 : * @param[in] fabric_id The fabric ID associated with the node's fabric
1663 : * @param[out] out_compressed_fabric_id Span where output will be written. Its size must be >= kCompressedFabricIdentifierSize.
1664 : * @returns a CHIP_ERROR (see above) on failure or CHIP_NO_ERROR otherwise.
1665 : */
1666 : CHIP_ERROR GenerateCompressedFabricId(const Crypto::P256PublicKey & root_public_key, uint64_t fabric_id,
1667 : MutableByteSpan & out_compressed_fabric_id);
1668 :
1669 : /**
1670 : * @brief Compute the compressed fabric identifier used for operational discovery service
1671 : * records from a Node's root public key and Fabric ID. This is a conveniance
1672 : * overload that writes to a uint64_t (CompressedFabricId) type.
1673 : *
1674 : * @param[in] rootPublicKey The root public key associated with the node's fabric
1675 : * @param[in] fabricId The fabric ID associated with the node's fabric
1676 : * @param[out] compressedFabricId output location for compressed fabric ID
1677 : * @returns a CHIP_ERROR on failure or CHIP_NO_ERROR otherwise.
1678 : */
1679 : CHIP_ERROR GenerateCompressedFabricId(const Crypto::P256PublicKey & rootPublicKey, uint64_t fabricId,
1680 : uint64_t & compressedFabricId);
1681 :
1682 : enum class CertificateChainValidationResult
1683 : {
1684 : kSuccess = 0,
1685 :
1686 : kRootFormatInvalid = 100,
1687 : kRootArgumentInvalid = 101,
1688 :
1689 : kICAFormatInvalid = 200,
1690 : kICAArgumentInvalid = 201,
1691 :
1692 : kLeafFormatInvalid = 300,
1693 : kLeafArgumentInvalid = 301,
1694 :
1695 : kChainInvalid = 400,
1696 :
1697 : kNoMemory = 500,
1698 :
1699 : kInternalFrameworkError = 600,
1700 : };
1701 :
1702 : CHIP_ERROR ValidateCertificateChain(const uint8_t * rootCertificate, size_t rootCertificateLen, const uint8_t * caCertificate,
1703 : size_t caCertificateLen, const uint8_t * leafCertificate, size_t leafCertificateLen,
1704 : CertificateChainValidationResult & result);
1705 :
1706 : enum class AttestationCertType
1707 : {
1708 : kPAA = 0,
1709 : kPAI = 1,
1710 : kDAC = 2,
1711 : };
1712 :
1713 : CHIP_ERROR VerifyAttestationCertificateFormat(const ByteSpan & cert, AttestationCertType certType);
1714 :
1715 : /**
1716 : * @brief Generate a VendorFabricBindingMessage as used by the Fabric Table Vendor ID Verification Procedure.
1717 : *
1718 : * @param[in] fabricBindingVersion - Version of binding payload to generate. outputSpan size requirements are based on this.
1719 : * @param[in] rootPublicKey - Root public key for the fabric in question
1720 : * @param[in] fabricId - Fabric ID for the fabric in question
1721 : * @param[in] vendorId - Vendor ID for the fabric in question
1722 : * @param[inout] outputSpan - Span that will receive the binding message. Must be large enough for the
1723 : * payload (otherwise CHIP_ERROR_BUFFER_TOO_SMALL) and will be resized to fit.
1724 : * @return CHIP_NO_ERROR on success, otherwise another CHIP_ERROR value representative of the failure.
1725 : */
1726 : CHIP_ERROR GenerateVendorFabricBindingMessage(FabricBindingVersion fabricBindingVersion, const P256PublicKey & rootPublicKey,
1727 : FabricId fabricId, uint16_t vendorId, MutableByteSpan & outputSpan);
1728 :
1729 : /**
1730 : * @brief Generate the message to be signed for the Fabric Table Vendor ID Verification Procedure.
1731 : *
1732 : * The Fabric Binding Version value will be recovered from the vendorFabricBindingMessage.
1733 : *
1734 : * @param fabricIndex - Fabric Index for the fabric in question
1735 : * @param clientChallenge - Client challenge to use
1736 : * @param attestationChallenge - Attestation challenge to use
1737 : * @param vendorFabricBindingMessage - The VendorFabricBindingMessage previously computed for the fabric
1738 : * @param vidVerificationStatement - The VID Verification Statement to include in signature (may be empty)
1739 : * @param outputSpan - Span that will receive the to-be-signed message. Must be large enough for the
1740 : * payload (otherwise CHIP_ERROR_BUFFER_TOO_SMALL) and will be resized to fit.
1741 : * @return CHIP_NO_ERROR on success, otherwise another CHIP_ERROR value representative of the failure.
1742 : */
1743 : CHIP_ERROR GenerateVendorIdVerificationToBeSigned(FabricIndex fabricIndex, const ByteSpan & clientChallenge,
1744 : const ByteSpan & attestationChallenge,
1745 : const ByteSpan & vendorFabricBindingMessage,
1746 : const ByteSpan & vidVerificationStatement, MutableByteSpan & outputSpan);
1747 :
1748 : /**
1749 : * @brief Validate notBefore timestamp of a certificate (candidateCertificate) against validity period of the
1750 : * issuer certificate (issuerCertificate).
1751 : *
1752 : * Errors are:
1753 : * - CHIP_ERROR_CERT_EXPIRED if the candidateCertificate timestamp does not satisfy the issuerCertificate's timestamp.
1754 : * - CHIP_ERROR_INVALID_ARGUMENT when passing an invalid argument.
1755 : * - CHIP_ERROR_INTERNAL on any unexpected crypto or data conversion errors.
1756 : *
1757 : * @param candidateCertificate A DER Certificate ByteSpan those notBefore timestamp to be evaluated.
1758 : * @param issuerCertificate A DER Certificate ByteSpan used to evaluate validity timestamp of the candidateCertificate.
1759 : *
1760 : * @returns a CHIP_ERROR (see above) on failure or CHIP_NO_ERROR otherwise.
1761 : **/
1762 : CHIP_ERROR IsCertificateValidAtIssuance(const ByteSpan & candidateCertificate, const ByteSpan & issuerCertificate);
1763 :
1764 : /**
1765 : * @brief Validate a certificate's validity date against current time.
1766 : *
1767 : * Errors are:
1768 : * - CHIP_ERROR_CERT_EXPIRED if the certificate has expired.
1769 : * - CHIP_ERROR_INVALID_ARGUMENT when passing an invalid argument.
1770 : * - CHIP_ERROR_INTERNAL on any unexpected crypto or data conversion errors.
1771 : *
1772 : * @param certificate A DER Certificate ByteSpan used as the validity reference to be checked against current time.
1773 : *
1774 : * @returns a CHIP_ERROR (see above) on failure or CHIP_NO_ERROR otherwise.
1775 : **/
1776 : CHIP_ERROR IsCertificateValidAtCurrentTime(const ByteSpan & certificate);
1777 :
1778 : CHIP_ERROR ExtractPubkeyFromX509Cert(const ByteSpan & certificate, Crypto::P256PublicKey & pubkey);
1779 :
1780 : /**
1781 : * @brief Extracts the Subject Key Identifier from an X509 Certificate.
1782 : **/
1783 : CHIP_ERROR ExtractSKIDFromX509Cert(const ByteSpan & certificate, MutableByteSpan & skid);
1784 :
1785 : /**
1786 : * @brief Extracts the Authority Key Identifier from an X509 Certificate.
1787 : **/
1788 : CHIP_ERROR ExtractAKIDFromX509Cert(const ByteSpan & certificate, MutableByteSpan & akid);
1789 :
1790 : /**
1791 : * @brief Extracts the CRL Distribution Point (CDP) extension from an X509 ASN.1 Encoded Certificate.
1792 : * The returned value only covers the URI of the CDP. Only a single URI distribution point
1793 : * GeneralName is supported, and only those that start with "http://" and "https://".
1794 : *
1795 : * @returns CHIP_ERROR_NOT_FOUND if not found or wrong format.
1796 : * CHIP_NO_ERROR otherwise.
1797 : **/
1798 : CHIP_ERROR ExtractCRLDistributionPointURIFromX509Cert(const ByteSpan & certificate, MutableCharSpan & cdpurl);
1799 :
1800 : /**
1801 : * @brief Extracts the CRL Distribution Point (CDP) extension's cRLIssuer Name from an X509 ASN.1 Encoded Certificate.
1802 : * The value is copied into buffer in a raw ASN.1 X.509 format. This format should be directly comparable
1803 : * with the result of ExtractSubjectFromX509Cert().
1804 : *
1805 : * @returns CHIP_ERROR_NOT_FOUND if not found or wrong format.
1806 : * CHIP_NO_ERROR otherwise.
1807 : **/
1808 : CHIP_ERROR ExtractCDPExtensionCRLIssuerFromX509Cert(const ByteSpan & certificate, MutableByteSpan & crlIssuer);
1809 :
1810 : /**
1811 : * @brief Extracts Serial Number from X509 Certificate.
1812 : **/
1813 : CHIP_ERROR ExtractSerialNumberFromX509Cert(const ByteSpan & certificate, MutableByteSpan & serialNumber);
1814 :
1815 : /**
1816 : * @brief Extracts Subject Distinguished Name from X509 Certificate. The value is copied into buffer in a raw ASN.1 X.509 format.
1817 : **/
1818 : CHIP_ERROR ExtractSubjectFromX509Cert(const ByteSpan & certificate, MutableByteSpan & subject);
1819 :
1820 : /**
1821 : * @brief Extracts Issuer Distinguished Name from X509 Certificate. The value is copied into buffer in a raw ASN.1 X.509 format.
1822 : **/
1823 : CHIP_ERROR ExtractIssuerFromX509Cert(const ByteSpan & certificate, MutableByteSpan & issuer);
1824 :
1825 : class PemEncoder
1826 : {
1827 : public:
1828 : /**
1829 : * @brief Construct a PEM encoder for element type `encodedElement` whose DER data is in `derBytes` span.
1830 : *
1831 : * LIFETIME: both encodedElement and derBytes lifetime must be >= PemEncoder lifetime.
1832 : * PemEncoder references these while processing `NextLine()` calls.
1833 : *
1834 : * @param encodedElement - Element type string to include in header/footer (e.g. "CERTIFICATE"). Caller must provide correct
1835 : * uppercase.
1836 : * @param derBytes - Byte span containing data to encode. May be empty.
1837 : */
1838 8 : explicit PemEncoder(const char * encodedElement, ByteSpan derBytes) : mEncodedElement(encodedElement), mDerBytes(derBytes) {}
1839 :
1840 : // No copies.
1841 : PemEncoder(const PemEncoder &) = delete;
1842 : PemEncoder & operator=(const PemEncoder &) = delete;
1843 :
1844 : /**
1845 : * @brief Returns the pointer to the next null-terminated line of the encoding, or nullptr if done.
1846 : *
1847 : * The returned pointer has the lifetime of this class and during that lifetime will always point
1848 : * to valid memory.
1849 : *
1850 : * When header/footer are written, the heading type (`encodedElement` value) such as
1851 : * `CERTIFICATE` is clamped so that the entire header line with `-----BEGIN ${encodedElement}-----`
1852 : * and footer line with `-----END ${encodedElement}-----` are not wider than 64 bytes. This
1853 : * will not happen in practice with the types of things this is meant to encode.
1854 : *
1855 : * Usage should be in a loop, for example:
1856 : *
1857 : * std::vector<std::string> pemLines;
1858 : *
1859 : * PemEncoder encoder("CERTIFICATE", TestCerts::sTestCert_PAA_FFF1_Cert);
1860 : *
1861 : * const char* line = encoder.NextLine();
1862 : * while (line)
1863 : * {
1864 : * pemLines.push_back(std::string{ line });
1865 : * line = encoder.NextLine();
1866 : * }
1867 : *
1868 : * @return a pointer to the internal line buffer for next line or nullptr when done.
1869 : */
1870 : const char * NextLine();
1871 :
1872 : private:
1873 : static constexpr size_t kNumBytesPerLine = 48u;
1874 : static constexpr size_t kLineBufferSize = 64u + 1u; // PEM expects 64 characters wide and a null terminator at least.
1875 : static_assert(kLineBufferSize == (BASE64_ENCODED_LEN(kNumBytesPerLine) + 1), "Internal incoherence of library configuration!");
1876 :
1877 : enum State : int
1878 : {
1879 : kPrintHeader = 0,
1880 : kPrintBody = 1,
1881 : kPrintFooter = 2,
1882 : kDone = 3,
1883 : };
1884 :
1885 : const char * mEncodedElement; // "CERTIFICATE", "EC PUBLIC KEY", etc. Must be capitalized by caller.
1886 : ByteSpan mDerBytes;
1887 : State mState = State::kPrintHeader;
1888 : size_t mProcessedBytes = 0;
1889 : StringBuilder<kLineBufferSize> mStringBuilder{};
1890 : };
1891 :
1892 : // Utility class to take subject Key IDs (AKID/SKID) and convert them to DCL format ("A5:FF:00.....:DE:AD").
1893 : class KeyIdStringifier
1894 : {
1895 : public:
1896 11 : KeyIdStringifier() = default;
1897 :
1898 : /**
1899 : * @brief Returns the null-terminated string buffer owned by the class containing converted KeyID.
1900 : *
1901 : * LIFETIME NOTE: The last returned value from KeyIdToHex is valid until the next call.
1902 : *
1903 : * This is optimized for standard 20-byte AKID/SKID but works for any length, truncating very long ones.
1904 : *
1905 : * @param keyIdBuffer - buffer of bytes of the key ID.
1906 : * @return pointer to class-owned storage of a null-terminated string in DCL format.
1907 : */
1908 15 : const char * KeyIdToHex(ByteSpan keyIdBuffer)
1909 : {
1910 15 : mStringBuilder.Reset();
1911 15 : if (keyIdBuffer.empty())
1912 : {
1913 1 : mStringBuilder.Add("<EMPTY KEY ID>");
1914 1 : return mStringBuilder.c_str();
1915 : }
1916 :
1917 14 : mStringBuilder.AddFormat("%02X", keyIdBuffer[0]);
1918 248 : for (size_t i = 1; i < keyIdBuffer.size(); ++i)
1919 : {
1920 234 : mStringBuilder.Add(":");
1921 234 : mStringBuilder.AddFormat("%02X", keyIdBuffer[i]);
1922 : }
1923 :
1924 14 : return mStringBuilder.AddMarkerIfOverflow().c_str();
1925 : }
1926 :
1927 : private:
1928 : StringBuilder<(Crypto::kAuthorityKeyIdentifierLength * 3) + 1> mStringBuilder;
1929 : };
1930 :
1931 : /**
1932 : * @brief Checks for resigned version of the certificate in the list and returns it.
1933 : *
1934 : * The following conditions SHOULD be satisfied for the certificate to qualify as
1935 : * a resigned version of a reference certificate:
1936 : * - SKID of the candidate and the reference certificate should match.
1937 : * - SubjectDN of the candidate and the reference certificate should match.
1938 : *
1939 : * If no resigned version is found then reference certificate itself is returned.
1940 : *
1941 : * @param referenceCertificate A DER certificate.
1942 : * @param candidateCertificates A pointer to the list of DER Certificates, which should be searched
1943 : * for the resigned version of `referenceCertificate`.
1944 : * @param candidateCertificatesCount Number of certificates in the `candidateCertificates` list.
1945 : * @param outCertificate A reference to the certificate or it's resigned version if found.
1946 : * Note that it points to either `referenceCertificate` or one of
1947 : * `candidateCertificates`, but it doesn't copy data.
1948 : *
1949 : * @returns error if there is certificate parsing/format issue or CHIP_NO_ERROR otherwise.
1950 : **/
1951 : CHIP_ERROR ReplaceCertIfResignedCertFound(const ByteSpan & referenceCertificate, const ByteSpan * candidateCertificates,
1952 : size_t candidateCertificatesCount, ByteSpan & outCertificate);
1953 :
1954 : /**
1955 : * Defines DN attribute types that can include endocing of VID/PID parameters.
1956 : */
1957 : enum class DNAttrType
1958 : {
1959 : kUnspecified = 0,
1960 : kCommonName = 1,
1961 : kMatterVID = 2,
1962 : kMatterPID = 3,
1963 : };
1964 :
1965 : /**
1966 : * @struct AttestationCertVidPid
1967 : *
1968 : * @brief
1969 : * A data structure representing Attestation Certificate VID and PID attributes.
1970 : */
1971 : struct AttestationCertVidPid
1972 : {
1973 : Optional<VendorId> mVendorId;
1974 : Optional<uint16_t> mProductId;
1975 :
1976 1351 : bool Initialized() const { return (mVendorId.HasValue() || mProductId.HasValue()); }
1977 : };
1978 :
1979 : /**
1980 : * @brief Extracts VID and PID attributes from the DN Attribute string.
1981 : * If attribute is not present the corresponding output value stays uninitialized.
1982 : *
1983 : * @return CHIP_ERROR_INVALID_ARGUMENT if wrong input is provided.
1984 : * CHIP_ERROR_WRONG_CERT_DN if encoding of kMatterVID and kMatterPID attributes is wrong.
1985 : * CHIP_NO_ERROR otherwise.
1986 : **/
1987 : CHIP_ERROR ExtractVIDPIDFromAttributeString(DNAttrType attrType, const ByteSpan & attr,
1988 : AttestationCertVidPid & vidpidFromMatterAttr, AttestationCertVidPid & vidpidFromCNAttr);
1989 :
1990 : /**
1991 : * @brief Extracts VID and PID attributes from the Subject DN of an X509 Certificate.
1992 : * If attribute is not present the corresponding output value stays uninitialized.
1993 : **/
1994 : CHIP_ERROR ExtractVIDPIDFromX509Cert(const ByteSpan & x509Cert, AttestationCertVidPid & vidpid);
1995 :
1996 : /**
1997 : * @brief The set of credentials needed to operate group message security with symmetric keys.
1998 : */
1999 : typedef struct GroupOperationalCredentials
2000 : {
2001 : /// Validity start time in microseconds since 2000-01-01T00:00:00 UTC ("the Epoch")
2002 : uint64_t start_time;
2003 : /// Session Id
2004 : uint16_t hash;
2005 : /// Operational group key
2006 : uint8_t encryption_key[Crypto::CHIP_CRYPTO_SYMMETRIC_KEY_LENGTH_BYTES];
2007 : /// Privacy key
2008 : uint8_t privacy_key[Crypto::CHIP_CRYPTO_SYMMETRIC_KEY_LENGTH_BYTES];
2009 : } GroupOperationalCredentials;
2010 :
2011 : /**
2012 : * @brief Opaque context used to protect a symmetric key. The key operations must
2013 : * be performed without exposing the protected key value.
2014 : */
2015 : class SymmetricKeyContext
2016 : {
2017 : public:
2018 : /**
2019 : * @brief Returns the symmetric key hash
2020 : *
2021 : * TODO: Replace GetKeyHash() with DeriveGroupSessionId(SymmetricKeyContext &, uint16_t & session_id)
2022 : *
2023 : * @return Group Key Hash
2024 : */
2025 : virtual uint16_t GetKeyHash() = 0;
2026 :
2027 13 : virtual ~SymmetricKeyContext() = default;
2028 : /**
2029 : * @brief Perform the message encryption as described in 4.7.2. (Security Processing of Outgoing Messages)
2030 : * @param[in] plaintext Outgoing message payload.
2031 : * @param[in] aad Additional data (message header contents)
2032 : * @param[in] nonce Nonce (Security Flags | Message Counter | Source Node ID)
2033 : * @param[out] mic Outgoing Message Integrity Check
2034 : * @param[out] ciphertext Outgoing encrypted payload. Must be at least as big as plaintext. The same buffer may be used both
2035 : * for ciphertext, and plaintext.
2036 : * @return CHIP_ERROR
2037 : */
2038 : virtual CHIP_ERROR MessageEncrypt(const ByteSpan & plaintext, const ByteSpan & aad, const ByteSpan & nonce,
2039 : MutableByteSpan & mic, MutableByteSpan & ciphertext) const = 0;
2040 : /**
2041 : * @brief Perform the message decryption as described in 4.7.3.(Security Processing of Incoming Messages)
2042 : * @param[in] ciphertext Incoming encrypted payload
2043 : * @param[in] aad Additional data (message header contents)
2044 : * @param[in] nonce Nonce (Security Flags | Message Counter | Source Node ID)
2045 : * @param[in] mic Incoming Message Integrity Check
2046 : * @param[out] plaintext Incoming message payload. Must be at least as big as ciphertext. The same buffer may be used both
2047 : * for plaintext, and ciphertext.
2048 : * @return CHIP_ERROR
2049 : */
2050 : virtual CHIP_ERROR MessageDecrypt(const ByteSpan & ciphertext, const ByteSpan & aad, const ByteSpan & nonce,
2051 : const ByteSpan & mic, MutableByteSpan & plaintext) const = 0;
2052 :
2053 : /**
2054 : * @brief Perform privacy encoding as described in 4.8.2. (Privacy Processing of Outgoing Messages)
2055 : * @param[in] input Message header to privacy encrypt
2056 : * @param[in] nonce Privacy Nonce = session_id | mic
2057 : * @param[out] output Message header obfuscated
2058 : * @return CHIP_ERROR
2059 : */
2060 : virtual CHIP_ERROR PrivacyEncrypt(const ByteSpan & input, const ByteSpan & nonce, MutableByteSpan & output) const = 0;
2061 :
2062 : /**
2063 : * @brief Perform privacy decoding as described in 4.8.3. (Privacy Processing of Incoming Messages)
2064 : * @param[in] input Message header to privacy decrypt
2065 : * @param[in] nonce Privacy Nonce = session_id | mic
2066 : * @param[out] output Message header deobfuscated
2067 : * @return CHIP_ERROR
2068 : */
2069 : virtual CHIP_ERROR PrivacyDecrypt(const ByteSpan & input, const ByteSpan & nonce, MutableByteSpan & output) const = 0;
2070 :
2071 : /**
2072 : * @brief Release resources such as dynamic memory used to allocate this instance of the SymmetricKeyContext
2073 : */
2074 : virtual void Release() = 0;
2075 : };
2076 :
2077 : /**
2078 : * @brief Derives the Operational Group Key using the Key Derivation Function (KDF) from the given epoch key.
2079 : * @param[in] epoch_key The epoch key. Must be CHIP_CRYPTO_SYMMETRIC_KEY_LENGTH_BYTES bytes length.
2080 : * @param[in] compressed_fabric_id The compressed fabric ID for the fabric (big endian byte string)
2081 : * @param[out] out_key Symmetric key used as the encryption key during message processing for group communication.
2082 : The buffer size must be at least CHIP_CRYPTO_SYMMETRIC_KEY_LENGTH_BYTES bytes length.
2083 : * @return Returns a CHIP_NO_ERROR on succcess, or CHIP_ERROR_INTERNAL if the provided key is invalid.
2084 : **/
2085 : CHIP_ERROR DeriveGroupOperationalKey(const ByteSpan & epoch_key, const ByteSpan & compressed_fabric_id, MutableByteSpan & out_key);
2086 :
2087 : /**
2088 : * @brief Derives the Group Session ID from a given operational group key using
2089 : * the Key Derivation Function (Group Key Hash)
2090 : * @param[in] operational_key The operational group key. Must be CHIP_CRYPTO_SYMMETRIC_KEY_LENGTH_BYTES bytes length.
2091 : * @param[out] session_id Output of the Group Key Hash
2092 : * @return Returns a CHIP_NO_ERROR on succcess, or CHIP_ERROR_INVALID_ARGUMENT if the provided key is invalid.
2093 : **/
2094 : CHIP_ERROR DeriveGroupSessionId(const ByteSpan & operational_key, uint16_t & session_id);
2095 :
2096 : /**
2097 : * @brief Derives the Privacy Group Key using the Key Derivation Function (KDF) from the given epoch key.
2098 : * @param[in] epoch_key The epoch key. Must be CHIP_CRYPTO_SYMMETRIC_KEY_LENGTH_BYTES bytes length.
2099 : * @param[out] out_key Symmetric key used as the privacy key during message processing for group communication.
2100 : * The buffer size must be at least CHIP_CRYPTO_SYMMETRIC_KEY_LENGTH_BYTES bytes length.
2101 : * @return Returns a CHIP_NO_ERROR on succcess, or CHIP_ERROR_INTERNAL if the provided key is invalid.
2102 : **/
2103 : CHIP_ERROR DeriveGroupPrivacyKey(const ByteSpan & epoch_key, MutableByteSpan & out_key);
2104 :
2105 : /**
2106 : * @brief Derives the complete set of credentials needed for group security.
2107 : *
2108 : * This function will derive the Encryption Key, Group Key Hash (Session Id), and Privacy Key
2109 : * for the given Epoch Key and Compressed Fabric Id.
2110 : * @param[in] epoch_key The epoch key. Must be CHIP_CRYPTO_SYMMETRIC_KEY_LENGTH_BYTES bytes length.
2111 : * @param[in] compressed_fabric_id The compressed fabric ID for the fabric (big endian byte string)
2112 : * @param[out] operational_credentials The set of Symmetric keys used during message processing for group communication.
2113 : * @return Returns a CHIP_NO_ERROR on succcess, or CHIP_ERROR_INTERNAL if the provided key is invalid.
2114 : **/
2115 : CHIP_ERROR DeriveGroupOperationalCredentials(const ByteSpan & epoch_key, const ByteSpan & compressed_fabric_id,
2116 : GroupOperationalCredentials & operational_credentials);
2117 : } // namespace Crypto
2118 : } // namespace chip
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