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 416916 : void ClearSecretData(uint8_t (&buf)[N])
243 : {
244 416916 : ClearSecretData(buf, N);
245 416916 : }
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 15633 : ECPKey() = default;
267 : ECPKey(const ECPKey &) = default;
268 1668 : ECPKey & operator=(const ECPKey &) = default;
269 :
270 : public:
271 15633 : 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 :
281 834 : virtual bool Matches(const ECPKey<Sig> & other) const
282 : {
283 1668 : return (this->Length() == other.Length()) &&
284 1668 : 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 5964 : ~SensitiveDataBuffer()
303 : {
304 : // Sanitize after use
305 5964 : ClearSecretData(mBytes);
306 5964 : }
307 5962 : 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 : 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 4557 : CHIP_ERROR SetLength(size_t length)
326 : {
327 4557 : VerifyOrReturnError(length <= kCapacity, CHIP_ERROR_INVALID_ARGUMENT);
328 4556 : mLength = length;
329 4556 : return CHIP_NO_ERROR;
330 : }
331 :
332 : /**
333 : * @brief Returns current length of the buffer
334 : */
335 5264 : size_t Length() const { return mLength; }
336 :
337 : /**
338 : * @brief Returns non-const pointer to start of the underlying buffer
339 : */
340 6270 : uint8_t * Bytes() { return &mBytes[0]; }
341 :
342 : /**
343 : * @brief Returns const pointer to start of the underlying buffer
344 : */
345 7966 : const uint8_t * ConstBytes() const { return &mBytes[0]; }
346 :
347 : /**
348 : * @brief Constructs span from the underlying buffer
349 : */
350 23 : ByteSpan Span() const { return ByteSpan(ConstBytes(), Length()); }
351 :
352 : /**
353 : * @brief Returns capacity of the buffer
354 : */
355 2683 : 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 1 : constexpr explicit SensitiveDataFixedBuffer(const FixedByteSpan<kCapacity> & value)
380 : {
381 1 : memcpy(&mBytes[0], value.data(), kCapacity);
382 1 : }
383 :
384 135414 : ~SensitiveDataFixedBuffer()
385 : {
386 : // Sanitize after use
387 135414 : ClearSecretData(mBytes);
388 135414 : }
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 1617 : 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 2 : FixedByteSpan<kCapacity> Span() const { return FixedByteSpan<kCapacity>(mBytes); }
409 :
410 : /**
411 : * @brief Returns capacity of the buffer
412 : */
413 1622 : 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 14783 : 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>
441 845 : constexpr P256PublicKey(const FixedByteSpan<N> & value)
442 845 : {
443 : static_assert(N == kP256_PublicKey_Length, "Can only initialize from proper sized byte span");
444 845 : memcpy(&bytes[0], value.data(), N);
445 845 : }
446 :
447 : template <size_t N>
448 966 : P256PublicKey & operator=(const FixedByteSpan<N> & value)
449 : {
450 : static_assert(N == kP256_PublicKey_Length, "Can only initialize from proper sized byte span");
451 966 : memcpy(&bytes[0], value.data(), N);
452 966 : return *this;
453 : }
454 :
455 4361 : SupportedECPKeyTypes Type() const override { return SupportedECPKeyTypes::ECP256R1; }
456 16960 : size_t Length() const override { return kP256_PublicKey_Length; }
457 6517 : operator uint8_t *() override { return bytes; }
458 2717 : operator const uint8_t *() const override { return bytes; }
459 3395 : const uint8_t * ConstBytes() const override { return &bytes[0]; }
460 32 : uint8_t * Bytes() override { return &bytes[0]; }
461 834 : bool IsUncompressed() const override
462 : {
463 834 : 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.
466 834 : 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 1816 : ECPKeypair() = default;
485 : ECPKeypair(const ECPKeypair &) = default;
486 : ECPKeypair & operator=(const ECPKeypair &) = default;
487 :
488 : public:
489 1816 : 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 : class P256KeypairBase : public ECPKeypair<P256PublicKey, P256ECDHDerivedSecret, P256ECDSASignature>
532 : {
533 : protected:
534 : // This base type can't be copied / assigned directly.
535 : // Sub-types should be either uncopyable or final.
536 1816 : P256KeypairBase() = default;
537 : P256KeypairBase(const P256KeypairBase &) = default;
538 : P256KeypairBase & operator=(const P256KeypairBase &) = default;
539 :
540 : public:
541 : /**
542 : * @brief Initialize the keypair.
543 : * @return Returns a CHIP_ERROR on error, CHIP_NO_ERROR otherwise
544 : **/
545 : virtual CHIP_ERROR Initialize(ECPKeyTarget key_target) = 0;
546 :
547 : /**
548 : * @brief Serialize the keypair.
549 : * @return Returns a CHIP_ERROR on error, CHIP_NO_ERROR otherwise
550 : **/
551 : virtual CHIP_ERROR Serialize(P256SerializedKeypair & output) const = 0;
552 :
553 : /**
554 : * @brief Deserialize the keypair.
555 : * @return Returns a CHIP_ERROR on error, CHIP_NO_ERROR otherwise
556 : **/
557 : virtual CHIP_ERROR Deserialize(P256SerializedKeypair & input) = 0;
558 : };
559 :
560 : class P256Keypair : public P256KeypairBase
561 : {
562 : public:
563 1816 : P256Keypair() = default;
564 : ~P256Keypair() override;
565 :
566 : // P256Keypair can't be copied / assigned.
567 : P256Keypair(const P256Keypair &) = delete;
568 : P256Keypair & operator=(const P256Keypair &) = delete;
569 :
570 : /**
571 : * @brief Initialize the keypair.
572 : * @return Returns a CHIP_ERROR on error, CHIP_NO_ERROR otherwise
573 : **/
574 : CHIP_ERROR Initialize(ECPKeyTarget key_target) override;
575 :
576 : /**
577 : * @brief Serialize the keypair.
578 : * @return Returns a CHIP_ERROR on error, CHIP_NO_ERROR otherwise
579 : **/
580 : CHIP_ERROR Serialize(P256SerializedKeypair & output) const override;
581 :
582 : /**
583 : * @brief Deserialize the keypair.
584 : * @return Returns a CHIP_ERROR on error, CHIP_NO_ERROR otherwise
585 : **/
586 : CHIP_ERROR Deserialize(P256SerializedKeypair & input) override;
587 :
588 : /**
589 : * @brief Generate a new Certificate Signing Request (CSR).
590 : * @param csr Newly generated CSR in DER format
591 : * @param csr_length The caller provides the length of input buffer (csr). The function returns the actual length of generated
592 : *CSR.
593 : * @return Returns a CHIP_ERROR on error, CHIP_NO_ERROR otherwise
594 : **/
595 : CHIP_ERROR NewCertificateSigningRequest(uint8_t * csr, size_t & csr_length) const override;
596 :
597 : /**
598 : * @brief A function to sign a msg using ECDSA
599 : * @param msg Message that needs to be signed
600 : * @param msg_length Length of message
601 : * @param out_signature Buffer that will hold the output signature. The signature consists of: 2 EC elements (r and s),
602 : * in raw <r,s> point form (see SEC1).
603 : * @return Returns a CHIP_ERROR on error, CHIP_NO_ERROR otherwise
604 : **/
605 : CHIP_ERROR ECDSA_sign_msg(const uint8_t * msg, size_t msg_length, P256ECDSASignature & out_signature) const override;
606 :
607 : /**
608 : * @brief A function to derive a shared secret using ECDH
609 : *
610 : * This implements the CHIP_Crypto_ECDH(PrivateKey myPrivateKey, PublicKey theirPublicKey) cryptographic primitive
611 : * from the specification, using this class's private key from `mKeypair` as `myPrivateKey` and the remote
612 : * public key from `remote_public_key` as `theirPublicKey`.
613 : *
614 : * @param remote_public_key Public key of remote peer with which we are trying to establish secure channel. remote_public_key is
615 : * ASN.1 DER encoded as padded big-endian field elements as described in SEC 1: Elliptic Curve Cryptography
616 : * [https://www.secg.org/sec1-v2.pdf]
617 : * @param out_secret Buffer to write out secret into. This is a byte array representing the x coordinate of the shared secret.
618 : * @return Returns a CHIP_ERROR on error, CHIP_NO_ERROR otherwise
619 : **/
620 : CHIP_ERROR ECDH_derive_secret(const P256PublicKey & remote_public_key, P256ECDHDerivedSecret & out_secret) const override;
621 :
622 : /**
623 : * @brief Loads a P256 keypair from raw private and public key byte spans.
624 : *
625 : * !!!!!! IMPORTANT !!!!!!!
626 : * Raw private keys SHOULD NOT be loaded directly without extreme care about ensuring they do not get retained in
627 : * memory (e.g. stack or heap) and have the shortest possible lifecycle. Please consider replacing basic example
628 : * usage of private key loading with delegation of signing to another part of the system that preferably has key
629 : * material isolation or protection.
630 : *
631 : * Combines the public and private key data into a serialized keypair format,
632 : * then deserializes it into this keypair object.
633 : *
634 : * @param private_key ByteSpan containing the raw private key bytes.
635 : * @param public_key ByteSpan containing the raw public key bytes.
636 : * @return CHIP_ERROR indicating success or failure of the operation.
637 : */
638 : CHIP_ERROR HazardousOperationLoadKeypairFromRaw(ByteSpan private_key, ByteSpan public_key);
639 :
640 : /** @brief Return public key for the keypair.
641 : **/
642 1220 : const P256PublicKey & Pubkey() const override { return mPublicKey; }
643 :
644 : #if CHIP_WITH_NLFAULTINJECTION
645 0 : P256PublicKey & TestOnlyMutablePubkey() { return mPublicKey; }
646 : #endif
647 :
648 : /** Release resources associated with this key pair */
649 : void Clear();
650 :
651 : protected:
652 : #if CHIP_WITH_NLFAULTINJECTION
653 : mutable P256PublicKey mPublicKey;
654 : #else
655 : P256PublicKey mPublicKey;
656 : #endif
657 : // P256PublicKey mPublicKey;
658 : mutable P256KeypairContext mKeypair;
659 : bool mInitialized = false;
660 : };
661 :
662 : /**
663 : * @brief Platform-specific symmetric key handle
664 : *
665 : * The class represents a key used by the Matter stack either in the form of raw key material or key
666 : * reference, depending on the platform. To achieve that, it contains an opaque context that can be
667 : * cast to a concrete representation used by the given platform.
668 : *
669 : * @note SymmetricKeyHandle is an abstract class to force child classes for each key handle type.
670 : * SymmetricKeyHandle class implements all the necessary components for handles.
671 : */
672 : template <size_t ContextSize>
673 : class SymmetricKeyHandle
674 : {
675 : public:
676 : SymmetricKeyHandle(const SymmetricKeyHandle &) = delete;
677 : SymmetricKeyHandle(SymmetricKeyHandle &&) = delete;
678 : void operator=(const SymmetricKeyHandle &) = delete;
679 : void operator=(SymmetricKeyHandle &&) = delete;
680 :
681 : /**
682 : * @brief Get internal context cast to the desired key representation
683 : */
684 : template <class T>
685 30639 : const T & As() const
686 : {
687 30639 : return *SafePointerCast<const T *>(&mContext);
688 : }
689 :
690 : /**
691 : * @brief Get internal context cast to the desired, mutable key representation
692 : */
693 : template <class T>
694 7864 : T & AsMutable()
695 : {
696 7864 : return *SafePointerCast<T *>(&mContext);
697 : }
698 :
699 : protected:
700 271529 : SymmetricKeyHandle() = default;
701 271693 : ~SymmetricKeyHandle() { ClearSecretData(mContext.mOpaque); }
702 :
703 : private:
704 : struct alignas(uintptr_t) OpaqueContext
705 : {
706 : uint8_t mOpaque[ContextSize] = {};
707 : } mContext;
708 : };
709 :
710 : using Symmetric128BitsKeyByteArray = uint8_t[CHIP_CRYPTO_SYMMETRIC_KEY_LENGTH_BYTES];
711 :
712 : /**
713 : * @brief Platform-specific 128-bit symmetric key handle
714 : */
715 : class Symmetric128BitsKeyHandle : public SymmetricKeyHandle<CHIP_CRYPTO_SYMMETRIC_KEY_LENGTH_BYTES>
716 : {
717 : };
718 :
719 : /**
720 : * @brief Platform-specific 128-bit AES key handle
721 : */
722 : class Aes128KeyHandle final : public Symmetric128BitsKeyHandle
723 : {
724 : };
725 :
726 : /**
727 : * @brief Platform-specific 128-bit HMAC key handle
728 : */
729 : class Hmac128KeyHandle final : public Symmetric128BitsKeyHandle
730 : {
731 : };
732 :
733 : /**
734 : * @brief Platform-specific HKDF key handle
735 : */
736 : class HkdfKeyHandle final : public SymmetricKeyHandle<CHIP_CONFIG_HKDF_KEY_HANDLE_CONTEXT_SIZE>
737 : {
738 : };
739 :
740 : /**
741 : * @brief Convert a raw ECDSA signature to ASN.1 signature (per X9.62) as used by TLS libraries.
742 : *
743 : * Errors are:
744 : * - CHIP_ERROR_INVALID_ARGUMENT on any argument being invalid (e.g. nullptr), wrong sizes,
745 : * wrong or unsupported format,
746 : * - CHIP_ERROR_BUFFER_TOO_SMALL on running out of space at runtime.
747 : * - CHIP_ERROR_INTERNAL on any unexpected processing error.
748 : *
749 : * @param[in] fe_length_bytes Field Element length in bytes (e.g. 32 for P256 curve)
750 : * @param[in] raw_sig Raw signature of <r,s> concatenated
751 : * @param[out] out_asn1_sig ASN.1 DER signature format output buffer. Size must have space for at least
752 : * kMax_ECDSA_X9Dot62_Asn1_Overhead. On CHIP_NO_ERROR, the out_asn1_sig buffer will be re-assigned
753 : * to have the correct size based on variable-length output.
754 : * @return Returns a CHIP_ERROR on error, CHIP_NO_ERROR otherwise
755 : */
756 : CHIP_ERROR EcdsaRawSignatureToAsn1(size_t fe_length_bytes, const ByteSpan & raw_sig, MutableByteSpan & out_asn1_sig);
757 :
758 : /**
759 : * @brief Convert an ASN.1 DER signature (per X9.62) as used by TLS libraries to SEC1 raw format
760 : *
761 : * Errors are:
762 : * - CHIP_ERROR_INVALID_ARGUMENT on any argument being invalid (e.g. nullptr), wrong sizes,
763 : * wrong or unsupported format,
764 : * - CHIP_ERROR_BUFFER_TOO_SMALL on running out of space at runtime.
765 : * - CHIP_ERROR_INTERNAL on any unexpected processing error.
766 : *
767 : * @param[in] fe_length_bytes Field Element length in bytes (e.g. 32 for P256 curve)
768 : * @param[in] asn1_sig ASN.1 DER signature input
769 : * @param[out] out_raw_sig Raw signature of <r,s> concatenated format output buffer. Size must be at
770 : * least >= `2 * fe_length_bytes`. On CHIP_NO_ERROR, the out_raw_sig buffer will be re-assigned
771 : * to have the correct size (2 * fe_length_bytes).
772 : * @return Returns a CHIP_ERROR on error, CHIP_NO_ERROR otherwise
773 : */
774 : CHIP_ERROR EcdsaAsn1SignatureToRaw(size_t fe_length_bytes, const ByteSpan & asn1_sig, MutableByteSpan & out_raw_sig);
775 :
776 : /**
777 : * @brief Utility to read a length field after a tag in a DER-encoded stream.
778 : * @param[in] reader Reader instance from which the input will be read
779 : * @param[out] length Length of the following element read from the stream
780 : * @return CHIP_ERROR_INVALID_ARGUMENT or CHIP_ERROR_BUFFER_TOO_SMALL on error, CHIP_NO_ERROR otherwise
781 : */
782 : CHIP_ERROR ReadDerLength(chip::Encoding::LittleEndian::Reader & reader, size_t & length);
783 :
784 : /**
785 : * @brief Utility to emit a DER-encoded INTEGER given a raw unsigned large integer
786 : * in big-endian order. The `out_der_integer` span is updated to reflect the final
787 : * variable length, including tag and length, and must have at least `kEmitDerIntegerOverhead`
788 : * extra space in addition to the `raw_integer.size()`.
789 : * @param[in] raw_integer Bytes of a large unsigned integer in big-endian, possibly including leading zeroes
790 : * @param[out] out_der_integer Buffer to receive the DER-encoded integer
791 : * @return Returns CHIP_ERROR_INVALID_ARGUMENT or CHIP_ERROR_BUFFER_TOO_SMALL on error, CHIP_NO_ERROR otherwise.
792 : */
793 : CHIP_ERROR ConvertIntegerRawToDer(const ByteSpan & raw_integer, MutableByteSpan & out_der_integer);
794 :
795 : /**
796 : * @brief Utility to emit a DER-encoded INTEGER given a raw unsigned large integer
797 : * in big-endian order. The `out_der_integer` span is updated to reflect the final
798 : * variable length, excluding tag and length, and must have at least `kEmitDerIntegerWithoutTagOverhead`
799 : * extra space in addition to the `raw_integer.size()`.
800 : * @param[in] raw_integer Bytes of a large unsigned integer in big-endian, possibly including leading zeroes
801 : * @param[out] out_der_integer Buffer to receive the DER-encoded integer
802 : * @return Returns CHIP_ERROR_INVALID_ARGUMENT or CHIP_ERROR_BUFFER_TOO_SMALL on error, CHIP_NO_ERROR otherwise.
803 : */
804 : CHIP_ERROR ConvertIntegerRawToDerWithoutTag(const ByteSpan & raw_integer, MutableByteSpan & out_der_integer);
805 :
806 : /**
807 : * @brief A function that implements AES-CCM encryption
808 : *
809 : * This implements the CHIP_Crypto_AEAD_GenerateEncrypt() cryptographic primitive
810 : * from the specification. For an empty plaintext, the user of the API can provide
811 : * an empty string, or a nullptr, and provide plaintext_length as 0. The output buffer,
812 : * ciphertext can also be an empty string, or a nullptr for this case.
813 : *
814 : * @param plaintext Plaintext to encrypt
815 : * @param plaintext_length Length of plain_text
816 : * @param aad Additional authentication data
817 : * @param aad_length Length of additional authentication data
818 : * @param key Encryption key
819 : * @param nonce Encryption nonce
820 : * @param nonce_length Length of encryption nonce
821 : * @param ciphertext Buffer to write ciphertext into. Caller must ensure this is large enough to hold the ciphertext
822 : * @param tag Buffer to write tag into. Caller must ensure this is large enough to hold the tag
823 : * @param tag_length Expected length of tag
824 : * @return Returns a CHIP_ERROR on error, CHIP_NO_ERROR otherwise
825 : * */
826 : CHIP_ERROR AES_CCM_encrypt(const uint8_t * plaintext, size_t plaintext_length, const uint8_t * aad, size_t aad_length,
827 : const Aes128KeyHandle & key, const uint8_t * nonce, size_t nonce_length, uint8_t * ciphertext,
828 : uint8_t * tag, size_t tag_length);
829 :
830 : /**
831 : * @brief A function that implements AES-CCM decryption
832 : *
833 : * This implements the CHIP_Crypto_AEAD_DecryptVerify() cryptographic primitive
834 : * from the specification. For an empty ciphertext, the user of the API can provide
835 : * an empty string, or a nullptr, and provide ciphertext_length as 0. The output buffer,
836 : * plaintext can also be an empty string, or a nullptr for this case.
837 : *
838 : * @param ciphertext Ciphertext to decrypt
839 : * @param ciphertext_length Length of ciphertext
840 : * @param aad Additional authentical data.
841 : * @param aad_length Length of additional authentication data
842 : * @param tag Tag to use to decrypt
843 : * @param tag_length Length of tag
844 : * @param key Decryption key
845 : * @param nonce Encryption nonce
846 : * @param nonce_length Length of encryption nonce
847 : * @param plaintext Buffer to write plaintext into
848 : * @return Returns a CHIP_ERROR on error, CHIP_NO_ERROR otherwise
849 : **/
850 : CHIP_ERROR AES_CCM_decrypt(const uint8_t * ciphertext, size_t ciphertext_length, const uint8_t * aad, size_t aad_length,
851 : const uint8_t * tag, size_t tag_length, const Aes128KeyHandle & key, const uint8_t * nonce,
852 : size_t nonce_length, uint8_t * plaintext);
853 :
854 : /**
855 : * @brief A function that implements AES-CTR encryption/decryption
856 : *
857 : * This implements the AES-CTR-Encrypt/Decrypt() cryptographic primitives per sections
858 : * 3.7.1 and 3.7.2 of the specification. For an empty input, the user of the API
859 : * can provide an empty string, or a nullptr, and provide input as 0.
860 : * The output buffer can also be an empty string, or a nullptr for this case.
861 : *
862 : * @param input Input text to encrypt/decrypt
863 : * @param input_length Length of ciphertext
864 : * @param key Decryption key
865 : * @param nonce Encryption nonce
866 : * @param nonce_length Length of encryption nonce
867 : * @param output Buffer to write output into
868 : * @return Returns a CHIP_ERROR on error, CHIP_NO_ERROR otherwise
869 : **/
870 : CHIP_ERROR AES_CTR_crypt(const uint8_t * input, size_t input_length, const Aes128KeyHandle & key, const uint8_t * nonce,
871 : size_t nonce_length, uint8_t * output);
872 :
873 : /**
874 : * @brief Generate a PKCS#10 CSR, usable for Matter, from a P256Keypair.
875 : *
876 : * This uses first principles ASN.1 encoding to avoid relying on the CHIPCryptoPAL backend
877 : * itself, other than to provide an implementation of a P256Keypair * that supports
878 : * at least `::Pubkey()` and `::ECDSA_sign_msg`. This allows using it with
879 : * OS/Platform-bridged private key handling, without requiring a specific
880 : * implementation of other bits like ASN.1.
881 : *
882 : * The CSR will have subject OU set to `CSA`. This is needed since omiting
883 : * subject altogether often trips CSR parsing code. The profile at the CA can
884 : * be configured to ignore CSR requested subject.
885 : *
886 : * @param keypair The key pair for which a CSR should be generated. Must not be null.
887 : * @param csr_span Span to hold the resulting CSR. Must have size at least kMIN_CSR_Buffer_Size.
888 : * Otherwise returns CHIP_ERROR_BUFFER_TOO_SMALL. It will get resized to
889 : * actual size needed on success.
890 :
891 : * @return Returns a CHIP_ERROR from P256Keypair or ASN.1 backend on error, CHIP_NO_ERROR otherwise
892 : **/
893 : CHIP_ERROR GenerateCertificateSigningRequest(const P256Keypair * keypair, MutableByteSpan & csr_span);
894 :
895 : /**
896 : * @brief Common code to validate ASN.1 format/size of a CSR, used by VerifyCertificateSigningRequest.
897 : *
898 : * Ensures it's not obviously malformed and doesn't have trailing garbage.
899 : *
900 : * @param csr CSR in DER format
901 : * @param csr_length The length of the CSR buffer
902 : * @return CHIP_ERROR_UNSUPPORTED_CERT_FORMAT on invalid format, CHIP_NO_ERROR otherwise.
903 : */
904 : CHIP_ERROR VerifyCertificateSigningRequestFormat(const uint8_t * csr, size_t csr_length);
905 :
906 : /**
907 : * @brief Verify the Certificate Signing Request (CSR). If successfully verified, it outputs the public key from the CSR.
908 : *
909 : * The CSR is valid if the format is correct, the signature validates with the embedded public
910 : * key, and there is no trailing garbage data.
911 : *
912 : * @param csr CSR in DER format
913 : * @param csr_length The length of the CSR
914 : * @param pubkey The public key from the verified CSR
915 : * @return Returns a CHIP_ERROR on error, CHIP_NO_ERROR otherwise
916 : **/
917 : CHIP_ERROR VerifyCertificateSigningRequest(const uint8_t * csr, size_t csr_length, P256PublicKey & pubkey);
918 :
919 : /**
920 : * @brief A function that implements SHA-256 hash
921 : *
922 : * This implements the CHIP_Crypto_Hash() cryptographic primitive
923 : * in the the specification.
924 : *
925 : * @param data The data to hash
926 : * @param data_length Length of the data
927 : * @param out_buffer Pointer to buffer to write output into
928 : * @return Returns a CHIP_ERROR on error, CHIP_NO_ERROR otherwise
929 : **/
930 :
931 : CHIP_ERROR Hash_SHA256(const uint8_t * data, size_t data_length, uint8_t * out_buffer);
932 :
933 : /**
934 : * @brief A function that implements SHA-1 hash
935 : * @param data The data to hash
936 : * @param data_length Length of the data
937 : * @param out_buffer Pointer to buffer to write output into
938 : * @return Returns a CHIP_ERROR on error, CHIP_NO_ERROR otherwise
939 : **/
940 :
941 : CHIP_ERROR Hash_SHA1(const uint8_t * data, size_t data_length, uint8_t * out_buffer);
942 :
943 : /**
944 : * @brief A class that defines stream based implementation of SHA-256 hash
945 : * It's expected that the object of this class can be safely copied.
946 : * All implementations must check for std::is_trivially_copyable.
947 : **/
948 :
949 : struct alignas(CHIP_CONFIG_SHA256_CONTEXT_ALIGN) HashSHA256OpaqueContext
950 : {
951 : uint8_t mOpaque[kMAX_Hash_SHA256_Context_Size];
952 : };
953 :
954 : class Hash_SHA256_stream
955 : {
956 : public:
957 : Hash_SHA256_stream();
958 : ~Hash_SHA256_stream();
959 :
960 : /**
961 : * @brief Re-initialize digest computation to an empty context.
962 : *
963 : * @return CHIP_ERROR_INTERNAL on failure to initialize the context,
964 : * CHIP_NO_ERROR otherwise.
965 : */
966 : CHIP_ERROR Begin();
967 :
968 : /**
969 : * @brief Add some data to the digest computation, updating internal state.
970 : *
971 : * @param[in] data The span of bytes to include in the digest update process.
972 : *
973 : * @return CHIP_ERROR_INTERNAL on failure to ingest the data, CHIP_NO_ERROR otherwise.
974 : */
975 : CHIP_ERROR AddData(const ByteSpan data);
976 :
977 : /**
978 : * @brief Get the intermediate padded digest for the current state of the stream.
979 : *
980 : * More data can be added before finish is called.
981 : *
982 : * @param[in,out] out_buffer Output buffer to receive the digest. `out_buffer` must
983 : * be at least `kSHA256_Hash_Length` bytes long. The `out_buffer` size
984 : * will be set to `kSHA256_Hash_Length` on success.
985 : *
986 : * @return CHIP_ERROR_INTERNAL on failure to compute the digest, CHIP_ERROR_BUFFER_TOO_SMALL
987 : * if out_buffer is too small, CHIP_NO_ERROR otherwise.
988 : */
989 : CHIP_ERROR GetDigest(MutableByteSpan & out_buffer);
990 :
991 : /**
992 : * @brief Finalize the stream digest computation, getting the final digest.
993 : *
994 : * @param[in,out] out_buffer Output buffer to receive the digest. `out_buffer` must
995 : * be at least `kSHA256_Hash_Length` bytes long. The `out_buffer` size
996 : * will be set to `kSHA256_Hash_Length` on success.
997 : *
998 : * @return CHIP_ERROR_INTERNAL on failure to compute the digest, CHIP_ERROR_BUFFER_TOO_SMALL
999 : * if out_buffer is too small, CHIP_NO_ERROR otherwise.
1000 : */
1001 : CHIP_ERROR Finish(MutableByteSpan & out_buffer);
1002 :
1003 : /**
1004 : * @brief Clear-out internal digest data to avoid lingering the state.
1005 : */
1006 : void Clear();
1007 :
1008 : private:
1009 : // Check if the digest computation has been initialized; implement this if your backend needs it.
1010 : bool IsInitialized();
1011 :
1012 : HashSHA256OpaqueContext mContext;
1013 : };
1014 :
1015 : class HKDF_sha
1016 : {
1017 : public:
1018 : HKDF_sha() = default;
1019 3991 : virtual ~HKDF_sha() = default;
1020 :
1021 : /**
1022 : * @brief A function that implements SHA-256 based HKDF
1023 : *
1024 : * This implements the CHIP_Crypto_KDF() cryptographic primitive
1025 : * in the the specification.
1026 : *
1027 : * Error values are:
1028 : * - CHIP_ERROR_INVALID_ARGUMENT: for any bad arguments or nullptr input on
1029 : * any pointer.
1030 : * - CHIP_ERROR_INTERNAL: for any unexpected error arising in the underlying
1031 : * cryptographic layers.
1032 : *
1033 : * @param secret The secret to use as the key to the HKDF
1034 : * @param secret_length Length of the secret
1035 : * @param salt Optional salt to use as input to the HKDF
1036 : * @param salt_length Length of the salt
1037 : * @param info Optional info to use as input to the HKDF
1038 : * @param info_length Length of the info
1039 : * @param out_buffer Pointer to buffer to write output into.
1040 : * @param out_length Size of the underlying out_buffer. That length of output key material will be generated in out_buffer.
1041 : * @return Returns a CHIP_ERROR on error, CHIP_NO_ERROR otherwise
1042 : **/
1043 :
1044 : virtual CHIP_ERROR HKDF_SHA256(const uint8_t * secret, size_t secret_length, const uint8_t * salt, size_t salt_length,
1045 : const uint8_t * info, size_t info_length, uint8_t * out_buffer, size_t out_length);
1046 : };
1047 :
1048 : class HMAC_sha
1049 : {
1050 : public:
1051 : HMAC_sha() = default;
1052 124 : virtual ~HMAC_sha() = default;
1053 :
1054 : /**
1055 : * @brief A function that implements SHA-256 based HMAC per FIPS1981.
1056 : *
1057 : * This implements the CHIP_Crypto_HMAC() cryptographic primitive
1058 : * in the the specification.
1059 : *
1060 : * The `out_length` must be at least kSHA256_Hash_Length, and only
1061 : * kSHA256_Hash_Length bytes are written to out_buffer.
1062 : *
1063 : * Error values are:
1064 : * - CHIP_ERROR_INVALID_ARGUMENT: for any bad arguments or nullptr input on
1065 : * any pointer.
1066 : * - CHIP_ERROR_INTERNAL: for any unexpected error arising in the underlying
1067 : * cryptographic layers.
1068 : *
1069 : * @param key The key to use for the HMAC operation
1070 : * @param key_length Length of the key
1071 : * @param message Message over which to compute the HMAC
1072 : * @param message_length Length of the message over which to compute the HMAC
1073 : * @param out_buffer Pointer to buffer into which to write the output.
1074 : * @param out_length Underlying size of the `out_buffer`.
1075 : * @return Returns a CHIP_ERROR on error, CHIP_NO_ERROR otherwise
1076 : **/
1077 :
1078 : virtual CHIP_ERROR HMAC_SHA256(const uint8_t * key, size_t key_length, const uint8_t * message, size_t message_length,
1079 : uint8_t * out_buffer, size_t out_length);
1080 :
1081 : /**
1082 : * @brief A function that implements SHA-256 based HMAC per FIPS1981.
1083 : *
1084 : * This implements the CHIP_Crypto_HMAC() cryptographic primitive
1085 : * in the the specification.
1086 : *
1087 : * The `out_length` must be at least kSHA256_Hash_Length, and only
1088 : * kSHA256_Hash_Length bytes are written to out_buffer.
1089 : *
1090 : * Error values are:
1091 : * - CHIP_ERROR_INVALID_ARGUMENT: for any bad arguments or nullptr input on
1092 : * any pointer.
1093 : * - CHIP_ERROR_INTERNAL: for any unexpected error arising in the underlying
1094 : * cryptographic layers.
1095 : *
1096 : * @param key The HMAC Key handle to use for the HMAC operation
1097 : * @param message Message over which to compute the HMAC
1098 : * @param message_length Length of the message over which to compute the HMAC
1099 : * @param out_buffer Pointer to buffer into which to write the output.
1100 : * @param out_length Underlying size of the `out_buffer`.
1101 : * @return Returns a CHIP_ERROR on error, CHIP_NO_ERROR otherwise
1102 : **/
1103 : virtual CHIP_ERROR HMAC_SHA256(const Hmac128KeyHandle & key, const uint8_t * message, size_t message_length,
1104 : uint8_t * out_buffer, size_t out_length);
1105 : };
1106 :
1107 : /**
1108 : * @brief A cryptographically secure random number generator based on NIST SP800-90A
1109 : * @param out_buffer Buffer into which to write random bytes
1110 : * @param out_length Number of random bytes to generate
1111 : * @return Returns a CHIP_ERROR on error, CHIP_NO_ERROR otherwise
1112 : **/
1113 : CHIP_ERROR DRBG_get_bytes(uint8_t * out_buffer, size_t out_length);
1114 :
1115 : /** @brief Entropy callback function
1116 : * @param data Callback-specific data pointer
1117 : * @param output Output data to fill
1118 : * @param len Length of output buffer
1119 : * @param olen The actual amount of data that was written to output buffer
1120 : * @return 0 if success
1121 : */
1122 : typedef int (*entropy_source)(void * data, uint8_t * output, size_t len, size_t * olen);
1123 :
1124 : /** @brief A function to add entropy sources to crypto library
1125 : *
1126 : * This function can be called multiple times to add multiple entropy sources. However,
1127 : * once the entropy source is added, it cannot be removed. Please make sure that the
1128 : * entropy source is valid for the lifetime of the application. Also, make sure that the
1129 : * same entropy source is not added multiple times, e.g.: by calling this function
1130 : * in class constructor or initialization function.
1131 : *
1132 : * @param fn_source Function pointer to the entropy source
1133 : * @param p_source Data that should be provided when fn_source is called
1134 : * @param threshold Minimum required from source before entropy is released
1135 : * @return Returns a CHIP_ERROR on error, CHIP_NO_ERROR otherwise
1136 : **/
1137 : CHIP_ERROR add_entropy_source(entropy_source fn_source, void * p_source, size_t threshold);
1138 :
1139 : class PBKDF2_sha256
1140 : {
1141 : public:
1142 : PBKDF2_sha256() = default;
1143 10 : virtual ~PBKDF2_sha256() = default;
1144 :
1145 : /** @brief Function to derive key using password. SHA256 hashing algorithm is used for calculating hmac.
1146 : * @param password password used for key derivation
1147 : * @param plen length of buffer containing password
1148 : * @param salt salt to use as input to the KDF
1149 : * @param slen length of salt
1150 : * @param iteration_count number of iterations to run
1151 : * @param key_length length of output key
1152 : * @param output output buffer where the key will be written
1153 : * @return Returns a CHIP_ERROR on error, CHIP_NO_ERROR otherwise
1154 : **/
1155 : virtual CHIP_ERROR pbkdf2_sha256(const uint8_t * password, size_t plen, const uint8_t * salt, size_t slen,
1156 : unsigned int iteration_count, uint32_t key_length, uint8_t * output);
1157 : };
1158 :
1159 : // TODO: Extract Spake2p to a separate header and replace the forward declaration with #include SessionKeystore.h
1160 : class SessionKeystore;
1161 :
1162 : /**
1163 : * The below class implements the draft 01 version of the Spake2+ protocol as
1164 : * defined in https://www.ietf.org/id/draft-bar-cfrg-spake2plus-01.html.
1165 : *
1166 : * The following describes the protocol flows:
1167 : *
1168 : * Commissioner Accessory
1169 : * ------------ ---------
1170 : *
1171 : * Init
1172 : * BeginProver
1173 : * ComputeRoundOne ------------->
1174 : * Init
1175 : * BeginVerifier
1176 : * /- ComputeRoundOne
1177 : * <------------- ComputeRoundTwo
1178 : * ComputeRoundTwo ------------->
1179 : * KeyConfirm KeyConfirm
1180 : * GetKeys GetKeys
1181 : *
1182 : **/
1183 : class Spake2p
1184 : {
1185 : public:
1186 : Spake2p(size_t fe_size, size_t point_size, size_t hash_size);
1187 158 : virtual ~Spake2p() = default;
1188 :
1189 : /**
1190 : * @brief Initialize Spake2+ with some context specific information.
1191 : *
1192 : * @param context The context is arbitrary but should include information about the
1193 : * protocol being run, contain the transcript for negotiation, include
1194 : * the PKBDF parameters, etc.
1195 : * @param context_len The length of the context.
1196 : *
1197 : * @return Returns a CHIP_ERROR on error, CHIP_NO_ERROR otherwise
1198 : **/
1199 : virtual CHIP_ERROR Init(const uint8_t * context, size_t context_len);
1200 :
1201 : /**
1202 : * @brief Free Spake2+ underlying objects.
1203 : **/
1204 : virtual void Clear() = 0;
1205 :
1206 : /**
1207 : * @brief Start the Spake2+ process as a verifier (i.e. an accessory being provisioned).
1208 : *
1209 : * @param my_identity The verifier identity. May be NULL if identities are not established.
1210 : * @param my_identity_len The verifier identity length.
1211 : * @param peer_identity The peer identity. May be NULL if identities are not established.
1212 : * @param peer_identity_len The peer identity length.
1213 : * @param w0in The input w0 (a parameter baked into the device or computed with ComputeW0).
1214 : * @param w0in_len The input w0 length.
1215 : * @param Lin The input L (a parameter baked into the device or computed with ComputeL).
1216 : * @param Lin_len The input L length.
1217 : *
1218 : * @return Returns a CHIP_ERROR on error, CHIP_NO_ERROR otherwise
1219 : **/
1220 : virtual CHIP_ERROR BeginVerifier(const uint8_t * my_identity, size_t my_identity_len, const uint8_t * peer_identity,
1221 : size_t peer_identity_len, const uint8_t * w0in, size_t w0in_len, const uint8_t * Lin,
1222 : size_t Lin_len);
1223 :
1224 : /**
1225 : * @brief Start the Spake2+ process as a prover (i.e. a commissioner).
1226 : *
1227 : * @param my_identity The prover identity. May be NULL if identities are not established.
1228 : * @param my_identity_len The prover identity length.
1229 : * @param peer_identity The peer identity. May be NULL if identities are not established.
1230 : * @param peer_identity_len The peer identity length.
1231 : * @param w0sin The input w0s (an output from the PBKDF).
1232 : * @param w0sin_len The input w0s length.
1233 : * @param w1sin The input w1s (an output from the PBKDF).
1234 : * @param w1sin_len The input w1s length.
1235 : *
1236 : * @return Returns a CHIP_ERROR on error, CHIP_NO_ERROR otherwise
1237 : **/
1238 : virtual CHIP_ERROR BeginProver(const uint8_t * my_identity, size_t my_identity_len, const uint8_t * peer_identity,
1239 : size_t peer_identity_len, const uint8_t * w0sin, size_t w0sin_len, const uint8_t * w1sin,
1240 : size_t w1sin_len);
1241 :
1242 : /**
1243 : * @brief Compute the first round of the protocol.
1244 : *
1245 : * @param pab X value from commissioner.
1246 : * @param pab_len X length.
1247 : * @param out The output first round Spake2+ contribution.
1248 : * @param out_len The output first round Spake2+ contribution length.
1249 : *
1250 : * @return Returns a CHIP_ERROR on error, CHIP_NO_ERROR otherwise
1251 : **/
1252 : virtual CHIP_ERROR ComputeRoundOne(const uint8_t * pab, size_t pab_len, uint8_t * out, size_t * out_len);
1253 :
1254 : /**
1255 : * @brief Compute the second round of the protocol.
1256 : *
1257 : * @param in The peer first round Spake2+ contribution.
1258 : * @param in_len The peer first round Spake2+ contribution length.
1259 : * @param out The output second round Spake2+ contribution.
1260 : * @param out_len The output second round Spake2+ contribution length.
1261 : *
1262 : * @return Returns a CHIP_ERROR on error, CHIP_NO_ERROR otherwise
1263 : **/
1264 : virtual CHIP_ERROR ComputeRoundTwo(const uint8_t * in, size_t in_len, uint8_t * out, size_t * out_len);
1265 :
1266 : /**
1267 : * @brief Confirm that each party computed the same keys.
1268 : *
1269 : * @param in The peer second round Spake2+ contribution.
1270 : * @param in_len The peer second round Spake2+ contribution length.
1271 : *
1272 : * @return Returns a CHIP_ERROR on error, CHIP_NO_ERROR otherwise
1273 : **/
1274 : virtual CHIP_ERROR KeyConfirm(const uint8_t * in, size_t in_len);
1275 :
1276 : /**
1277 : * @brief Return the shared HKDF key.
1278 : *
1279 : * Returns the shared key established during the Spake2+ process, which can be used
1280 : * to derive application-specific keys using HKDF.
1281 : *
1282 : * @param keystore The session keystore for managing the HKDF key lifetime.
1283 : * @param key The output HKDF key.
1284 : *
1285 : * @return Returns a CHIP_ERROR on error, CHIP_NO_ERROR otherwise
1286 : **/
1287 : CHIP_ERROR GetKeys(SessionKeystore & keystore, HkdfKeyHandle & key);
1288 :
1289 : CHIP_ERROR InternalHash(const uint8_t * in, size_t in_len);
1290 : CHIP_ERROR WriteMN();
1291 : CHIP_ERROR GenerateKeys();
1292 :
1293 : /**
1294 : * @brief Load a field element.
1295 : *
1296 : * @param in The input big endian field element.
1297 : * @param in_len The size of the input buffer in bytes.
1298 : * @param fe A pointer to an initialized implementation dependant field element.
1299 : *
1300 : * @return Returns a CHIP_ERROR on error, CHIP_NO_ERROR otherwise
1301 : **/
1302 : virtual CHIP_ERROR FELoad(const uint8_t * in, size_t in_len, void * fe) = 0;
1303 :
1304 : /**
1305 : * @brief Write a field element in big-endian format.
1306 : *
1307 : * @param fe The field element to write.
1308 : * @param out The output buffer.
1309 : * @param out_len The length of the output buffer.
1310 : *
1311 : * @return Returns a CHIP_ERROR on error, CHIP_NO_ERROR otherwise
1312 : **/
1313 : virtual CHIP_ERROR FEWrite(const void * fe, uint8_t * out, size_t out_len) = 0;
1314 :
1315 : /**
1316 : * @brief Generate a field element.
1317 : *
1318 : * @param fe A pointer to an initialized implementation dependant field element.
1319 : *
1320 : * @note The implementation must generate a random element from [0, q) where q is the curve order.
1321 : *
1322 : * @return Returns a CHIP_ERROR on error, CHIP_NO_ERROR otherwise
1323 : **/
1324 : virtual CHIP_ERROR FEGenerate(void * fe) = 0;
1325 :
1326 : /**
1327 : * @brief Multiply two field elements, fer = fe1 * fe2.
1328 : *
1329 : * @param fer A pointer to an initialized implementation dependant field element.
1330 : * @param fe1 A pointer to an initialized implementation dependant field element.
1331 : * @param fe2 A pointer to an initialized implementation dependant field element.
1332 : *
1333 : * @note The result must be a field element (i.e. reduced by the curve order).
1334 : *
1335 : * @return Returns a CHIP_ERROR on error, CHIP_NO_ERROR otherwise
1336 : **/
1337 : virtual CHIP_ERROR FEMul(void * fer, const void * fe1, const void * fe2) = 0;
1338 :
1339 : /**
1340 : * @brief Load a point from 0x04 || X || Y format
1341 : *
1342 : * @param in Input buffer
1343 : * @param in_len Input buffer length
1344 : * @param R A pointer to an initialized implementation dependant point.
1345 : *
1346 : * @return Returns a CHIP_ERROR on error, CHIP_NO_ERROR otherwise
1347 : **/
1348 : virtual CHIP_ERROR PointLoad(const uint8_t * in, size_t in_len, void * R) = 0;
1349 :
1350 : /**
1351 : * @brief Write a point in 0x04 || X || Y format
1352 : *
1353 : * @param R A pointer to an initialized implementation dependant point.
1354 : * @param out Output buffer
1355 : * @param out_len Length of the output buffer
1356 : *
1357 : * @return Returns a CHIP_ERROR on error, CHIP_NO_ERROR otherwise
1358 : **/
1359 : virtual CHIP_ERROR PointWrite(const void * R, uint8_t * out, size_t out_len) = 0;
1360 :
1361 : /**
1362 : * @brief Scalar multiplication, R = fe1 * P1.
1363 : *
1364 : * @param R Resultant point
1365 : * @param P1 Input point
1366 : * @param fe1 Input field element.
1367 : *
1368 : * @return Returns a CHIP_ERROR on error, CHIP_NO_ERROR otherwise
1369 : **/
1370 : virtual CHIP_ERROR PointMul(void * R, const void * P1, const void * fe1) = 0;
1371 :
1372 : /**
1373 : * @brief Scalar multiplication with addition, R = fe1 * P1 + fe2 * P2.
1374 : *
1375 : * @param R Resultant point
1376 : * @param P1 Input point
1377 : * @param fe1 Input field element.
1378 : * @param P2 Input point
1379 : * @param fe2 Input field element.
1380 : *
1381 : * @return Returns a CHIP_ERROR on error, CHIP_NO_ERROR otherwise
1382 : **/
1383 : virtual CHIP_ERROR PointAddMul(void * R, const void * P1, const void * fe1, const void * P2, const void * fe2) = 0;
1384 :
1385 : /**
1386 : * @brief Point inversion.
1387 : *
1388 : * @param R Input/Output point to point_invert
1389 : *
1390 : * @return Returns a CHIP_ERROR on error, CHIP_NO_ERROR otherwise
1391 : **/
1392 : virtual CHIP_ERROR PointInvert(void * R) = 0;
1393 :
1394 : /**
1395 : * @brief Multiply a point by the curve cofactor.
1396 : *
1397 : * @param R Input/Output point to point_invert
1398 : *
1399 : * @return Returns a CHIP_ERROR on error, CHIP_NO_ERROR otherwise
1400 : **/
1401 : virtual CHIP_ERROR PointCofactorMul(void * R) = 0;
1402 :
1403 : /*
1404 : * @synopsis Check if a point is on the curve.
1405 : *
1406 : * @param R Input point to check.
1407 : *
1408 : * @return CHIP_NO_ERROR if the point is valid, CHIP_ERROR otherwise.
1409 : */
1410 : virtual CHIP_ERROR PointIsValid(void * R) = 0;
1411 :
1412 : /*
1413 : * @synopsis Compute w0sin mod p
1414 : *
1415 : * @param w0out Output field element w0
1416 : * @param w0_len Output field element length
1417 : * @param w0sin Input field element
1418 : * @param w0sin_len Input field element length
1419 : *
1420 : * @return Returns a CHIP_ERROR on error, CHIP_NO_ERROR otherwise
1421 : **/
1422 : virtual CHIP_ERROR ComputeW0(uint8_t * w0out, size_t * w0_len, const uint8_t * w0sin, size_t w0sin_len) = 0;
1423 :
1424 : /*
1425 : * @synopsis Compute w1in*G where w1in is w1sin mod p
1426 : *
1427 : * @param Lout Output point in 0x04 || X || Y format.
1428 : * @param L_len Output point length
1429 : * @param w1sin Input field element
1430 : * @param w1sin_len Input field element size
1431 : *
1432 : * @return Returns a CHIP_ERROR on error, CHIP_NO_ERROR otherwise
1433 : **/
1434 : virtual CHIP_ERROR ComputeL(uint8_t * Lout, size_t * L_len, const uint8_t * w1sin, size_t w1sin_len) = 0;
1435 :
1436 : void * M;
1437 : void * N;
1438 : const void * G;
1439 : void * X;
1440 : void * Y;
1441 : void * L;
1442 : void * Z;
1443 : void * V;
1444 : void * w0;
1445 : void * w1;
1446 : void * xy;
1447 : void * order;
1448 : void * tempbn;
1449 :
1450 : protected:
1451 : /**
1452 : * @brief Initialize underlying implementation curve, points, field elements, etc.
1453 : *
1454 : * @details The implementation needs to:
1455 : * 1. Initialize each of the points below and set the relevant pointers on the class:
1456 : * a. M
1457 : * b. N
1458 : * c. G
1459 : * d. X
1460 : * e. Y
1461 : * f. L
1462 : * g. Z
1463 : * h. V
1464 : *
1465 : * As an example:
1466 : * this.M = implementation_alloc_point();
1467 : * 2. Initialize each of the field elements below and set the relevant pointers on the class:
1468 : * a. w0
1469 : * b. w1
1470 : * c. xy
1471 : * d. tempbn
1472 : * 3. The hashing context should be initialized
1473 : *
1474 : * @return Returns a CHIP_ERROR on error, CHIP_NO_ERROR otherwise
1475 : **/
1476 : virtual CHIP_ERROR InitImpl() = 0;
1477 :
1478 : /**
1479 : * @brief Hash in_len bytes of in into the internal hash context.
1480 : *
1481 : * @param in The input buffer.
1482 : * @param in_len Size of the input buffer in bytes.
1483 : *
1484 : * @return Returns a CHIP_ERROR on error, CHIP_NO_ERROR otherwise
1485 : **/
1486 : virtual CHIP_ERROR Hash(const uint8_t * in, size_t in_len) = 0;
1487 :
1488 : /**
1489 : * @brief Return the hash.
1490 : *
1491 : * @param out_span Output buffer. The size available must be >= the hash size. It gets resized
1492 : * to hash size on success.
1493 : *
1494 : * @return Returns a CHIP_ERROR on error, CHIP_NO_ERROR otherwise
1495 : **/
1496 : virtual CHIP_ERROR HashFinalize(MutableByteSpan & out_span) = 0;
1497 :
1498 : /**
1499 : * @brief Generate a message authentication code.
1500 : *
1501 : * @param key The MAC key buffer.
1502 : * @param key_len The size of the MAC key in bytes.
1503 : * @param in The input buffer.
1504 : * @param in_len The size of the input data to MAC in bytes.
1505 : * @param out_span The output MAC buffer span. Size must be >= the hash_size. Output size is updated to fit on success.
1506 : *
1507 : * @return Returns a CHIP_ERROR on error, CHIP_NO_ERROR otherwise
1508 : **/
1509 : virtual CHIP_ERROR Mac(const uint8_t * key, size_t key_len, const uint8_t * in, size_t in_len, MutableByteSpan & out_span) = 0;
1510 :
1511 : /**
1512 : * @brief Verify a message authentication code.
1513 : *
1514 : * @param key The MAC key buffer.
1515 : * @param key_len The size of the MAC key in bytes.
1516 : * @param mac The input MAC buffer.
1517 : * @param mac_len The size of the MAC in bytes.
1518 : * @param in The input buffer to verify.
1519 : * @param in_len The size of the input data to verify in bytes.
1520 : *
1521 : * @return Returns a CHIP_ERROR when the MAC doesn't validate, CHIP_NO_ERROR otherwise.
1522 : **/
1523 : virtual CHIP_ERROR MacVerify(const uint8_t * key, size_t key_len, const uint8_t * mac, size_t mac_len, const uint8_t * in,
1524 : size_t in_len) = 0;
1525 :
1526 : /**
1527 : * @brief Derive an key of length out_len.
1528 : *
1529 : * @param ikm The input key material buffer.
1530 : * @param ikm_len The input key material length.
1531 : * @param salt The optional salt. This may be NULL.
1532 : * @param salt_len The size of the salt in bytes.
1533 : * @param info The info.
1534 : * @param info_len The size of the info in bytes.
1535 : * @param out The output key
1536 : * @param out_len The output key length
1537 : *
1538 : * @return Returns a CHIP_ERROR when the MAC doesn't validate, CHIP_NO_ERROR otherwise.
1539 : **/
1540 : virtual CHIP_ERROR KDF(const uint8_t * ikm, size_t ikm_len, const uint8_t * salt, size_t salt_len, const uint8_t * info,
1541 : size_t info_len, uint8_t * out, size_t out_len) = 0;
1542 :
1543 : CHIP_SPAKE2P_ROLE role;
1544 : CHIP_SPAKE2P_STATE state = CHIP_SPAKE2P_STATE::PREINIT;
1545 : size_t fe_size;
1546 : size_t hash_size;
1547 : size_t point_size;
1548 : uint8_t Kcab[kMAX_Hash_Length];
1549 : uint8_t Kae[kMAX_Hash_Length];
1550 : uint8_t * Kca;
1551 : uint8_t * Kcb;
1552 : uint8_t * Ka;
1553 : uint8_t * Ke;
1554 : };
1555 :
1556 : struct alignas(size_t) Spake2pOpaqueContext
1557 : {
1558 : uint8_t mOpaque[kMAX_Spake2p_Context_Size];
1559 : };
1560 :
1561 : class Spake2p_P256_SHA256_HKDF_HMAC : public Spake2p
1562 : {
1563 : public:
1564 158 : Spake2p_P256_SHA256_HKDF_HMAC() : Spake2p(kP256_FE_Length, kP256_Point_Length, kSHA256_Hash_Length)
1565 : {
1566 158 : memset(&mSpake2pContext, 0, sizeof(mSpake2pContext));
1567 158 : }
1568 :
1569 158 : ~Spake2p_P256_SHA256_HKDF_HMAC() override { Spake2p_P256_SHA256_HKDF_HMAC::Clear(); }
1570 :
1571 : void Clear() override;
1572 : CHIP_ERROR Mac(const uint8_t * key, size_t key_len, const uint8_t * in, size_t in_len, MutableByteSpan & out_span) override;
1573 : CHIP_ERROR MacVerify(const uint8_t * key, size_t key_len, const uint8_t * mac, size_t mac_len, const uint8_t * in,
1574 : size_t in_len) override;
1575 : CHIP_ERROR FELoad(const uint8_t * in, size_t in_len, void * fe) override;
1576 : CHIP_ERROR FEWrite(const void * fe, uint8_t * out, size_t out_len) override;
1577 : CHIP_ERROR FEGenerate(void * fe) override;
1578 : CHIP_ERROR FEMul(void * fer, const void * fe1, const void * fe2) override;
1579 :
1580 : CHIP_ERROR PointLoad(const uint8_t * in, size_t in_len, void * R) override;
1581 : CHIP_ERROR PointWrite(const void * R, uint8_t * out, size_t out_len) override;
1582 : CHIP_ERROR PointMul(void * R, const void * P1, const void * fe1) override;
1583 : CHIP_ERROR PointAddMul(void * R, const void * P1, const void * fe1, const void * P2, const void * fe2) override;
1584 : CHIP_ERROR PointInvert(void * R) override;
1585 : CHIP_ERROR PointCofactorMul(void * R) override;
1586 : CHIP_ERROR PointIsValid(void * R) override;
1587 :
1588 : CHIP_ERROR ComputeW0(uint8_t * w0out, size_t * w0_len, const uint8_t * w0sin, size_t w0sin_len) override;
1589 : CHIP_ERROR ComputeL(uint8_t * Lout, size_t * L_len, const uint8_t * w1sin, size_t w1sin_len) override;
1590 :
1591 : protected:
1592 : CHIP_ERROR InitImpl() override;
1593 : CHIP_ERROR Hash(const uint8_t * in, size_t in_len) override;
1594 : CHIP_ERROR HashFinalize(MutableByteSpan & out_span) override;
1595 : CHIP_ERROR KDF(const uint8_t * secret, size_t secret_length, const uint8_t * salt, size_t salt_length, const uint8_t * info,
1596 : size_t info_length, uint8_t * out, size_t out_length) override;
1597 :
1598 : private:
1599 : CHIP_ERROR InitInternal();
1600 : Hash_SHA256_stream sha256_hash_ctx;
1601 :
1602 : Spake2pOpaqueContext mSpake2pContext;
1603 : };
1604 :
1605 : /**
1606 : * @brief Class used for verifying PASE secure sessions.
1607 : **/
1608 : class Spake2pVerifier
1609 : {
1610 : public:
1611 : uint8_t mW0[kP256_FE_Length];
1612 : uint8_t mL[kP256_Point_Length];
1613 :
1614 : CHIP_ERROR Serialize(MutableByteSpan & outSerialized) const;
1615 : CHIP_ERROR Deserialize(const ByteSpan & inSerialized);
1616 :
1617 : /**
1618 : * @brief Generate the Spake2+ verifier.
1619 : *
1620 : * @param pbkdf2IterCount Iteration count for PBKDF2 function
1621 : * @param salt Salt to be used for Spake2+ operation
1622 : * @param setupPin Provided setup PIN (passcode)
1623 : *
1624 : * @return CHIP_ERROR The result of Spake2+ verifier generation
1625 : */
1626 : CHIP_ERROR Generate(uint32_t pbkdf2IterCount, const ByteSpan & salt, uint32_t setupPin);
1627 :
1628 : /**
1629 : * @brief Compute the initiator values (w0s, w1s) used for PAKE input.
1630 : *
1631 : * @param pbkdf2IterCount Iteration count for PBKDF2 function
1632 : * @param salt Salt to be used for Spake2+ operation
1633 : * @param setupPin Provided setup PIN (passcode)
1634 : * @param ws The output pair (w0s, w1s) stored sequentially
1635 : * @param ws_len The output length
1636 : *
1637 : * @return CHIP_ERROR The result from running PBKDF2
1638 : */
1639 : static CHIP_ERROR ComputeWS(uint32_t pbkdf2IterCount, const ByteSpan & salt, uint32_t setupPin, uint8_t * ws, uint32_t ws_len);
1640 : };
1641 :
1642 : /**
1643 : * @brief Serialized format of the Spake2+ Verifier components.
1644 : *
1645 : * This is used when the Verifier should be presented in a serialized form.
1646 : * For example, when it is generated using PBKDF function, when stored in the
1647 : * memory or when sent over the wire.
1648 : * The serialized format is concatentation of 'W0' and 'L' verifier components:
1649 : * { Spake2pVerifier.mW0[kP256_FE_Length], Spake2pVerifier.mL[kP256_Point_Length] }
1650 : **/
1651 : typedef uint8_t Spake2pVerifierSerialized[kSpake2p_VerifierSerialized_Length];
1652 :
1653 : /**
1654 : * @brief Compute the compressed fabric identifier used for operational discovery service
1655 : * records from a Node's root public key and Fabric ID. On success, out_compressed_fabric_id
1656 : * will have a size of exactly kCompressedFabricIdentifierSize.
1657 : *
1658 : * Errors are:
1659 : * - CHIP_ERROR_INVALID_ARGUMENT if root_public_key is invalid
1660 : * - CHIP_ERROR_BUFFER_TOO_SMALL if out_compressed_fabric_id is too small for serialization
1661 : * - CHIP_ERROR_INTERNAL on any unexpected crypto or data conversion errors.
1662 : *
1663 : * @param[in] root_public_key The root public key associated with the node's fabric
1664 : * @param[in] fabric_id The fabric ID associated with the node's fabric
1665 : * @param[out] out_compressed_fabric_id Span where output will be written. Its size must be >= kCompressedFabricIdentifierSize.
1666 : * @returns a CHIP_ERROR (see above) on failure or CHIP_NO_ERROR otherwise.
1667 : */
1668 : CHIP_ERROR GenerateCompressedFabricId(const Crypto::P256PublicKey & root_public_key, uint64_t fabric_id,
1669 : MutableByteSpan & out_compressed_fabric_id);
1670 :
1671 : /**
1672 : * @brief Compute the compressed fabric identifier used for operational discovery service
1673 : * records from a Node's root public key and Fabric ID. This is a conveniance
1674 : * overload that writes to a uint64_t (CompressedFabricId) type.
1675 : *
1676 : * @param[in] rootPublicKey The root public key associated with the node's fabric
1677 : * @param[in] fabricId The fabric ID associated with the node's fabric
1678 : * @param[out] compressedFabricId output location for compressed fabric ID
1679 : * @returns a CHIP_ERROR on failure or CHIP_NO_ERROR otherwise.
1680 : */
1681 : CHIP_ERROR GenerateCompressedFabricId(const Crypto::P256PublicKey & rootPublicKey, uint64_t fabricId,
1682 : uint64_t & compressedFabricId);
1683 :
1684 : enum class CertificateChainValidationResult
1685 : {
1686 : kSuccess = 0,
1687 :
1688 : kRootFormatInvalid = 100,
1689 : kRootArgumentInvalid = 101,
1690 :
1691 : kICAFormatInvalid = 200,
1692 : kICAArgumentInvalid = 201,
1693 :
1694 : kLeafFormatInvalid = 300,
1695 : kLeafArgumentInvalid = 301,
1696 :
1697 : kChainInvalid = 400,
1698 :
1699 : kNoMemory = 500,
1700 :
1701 : kInternalFrameworkError = 600,
1702 : };
1703 :
1704 : CHIP_ERROR ValidateCertificateChain(const uint8_t * rootCertificate, size_t rootCertificateLen, const uint8_t * caCertificate,
1705 : size_t caCertificateLen, const uint8_t * leafCertificate, size_t leafCertificateLen,
1706 : CertificateChainValidationResult & result);
1707 :
1708 : enum class AttestationCertType
1709 : {
1710 : kPAA = 0,
1711 : kPAI = 1,
1712 : kDAC = 2,
1713 : };
1714 :
1715 : CHIP_ERROR VerifyAttestationCertificateFormat(const ByteSpan & cert, AttestationCertType certType);
1716 :
1717 : /**
1718 : * @brief Generate a VendorFabricBindingMessage as used by the Fabric Table Vendor ID Verification Procedure.
1719 : *
1720 : * @param[in] fabricBindingVersion - Version of binding payload to generate. outputSpan size requirements are based on this.
1721 : * @param[in] rootPublicKey - Root public key for the fabric in question
1722 : * @param[in] fabricId - Fabric ID for the fabric in question
1723 : * @param[in] vendorId - Vendor ID for the fabric in question
1724 : * @param[inout] outputSpan - Span that will receive the binding message. Must be large enough for the
1725 : * payload (otherwise CHIP_ERROR_BUFFER_TOO_SMALL) and will be resized to fit.
1726 : * @return CHIP_NO_ERROR on success, otherwise another CHIP_ERROR value representative of the failure.
1727 : */
1728 : CHIP_ERROR GenerateVendorFabricBindingMessage(FabricBindingVersion fabricBindingVersion, const P256PublicKey & rootPublicKey,
1729 : FabricId fabricId, uint16_t vendorId, MutableByteSpan & outputSpan);
1730 :
1731 : /**
1732 : * @brief Generate the message to be signed for the Fabric Table Vendor ID Verification Procedure.
1733 : *
1734 : * The Fabric Binding Version value will be recovered from the vendorFabricBindingMessage.
1735 : *
1736 : * @param fabricIndex - Fabric Index for the fabric in question
1737 : * @param clientChallenge - Client challenge to use
1738 : * @param attestationChallenge - Attestation challenge to use
1739 : * @param vendorFabricBindingMessage - The VendorFabricBindingMessage previously computed for the fabric
1740 : * @param vidVerificationStatement - The VID Verification Statement to include in signature (may be empty)
1741 : * @param outputSpan - Span that will receive the to-be-signed message. Must be large enough for the
1742 : * payload (otherwise CHIP_ERROR_BUFFER_TOO_SMALL) and will be resized to fit.
1743 : * @return CHIP_NO_ERROR on success, otherwise another CHIP_ERROR value representative of the failure.
1744 : */
1745 : CHIP_ERROR GenerateVendorIdVerificationToBeSigned(FabricIndex fabricIndex, const ByteSpan & clientChallenge,
1746 : const ByteSpan & attestationChallenge,
1747 : const ByteSpan & vendorFabricBindingMessage,
1748 : const ByteSpan & vidVerificationStatement, MutableByteSpan & outputSpan);
1749 :
1750 : /**
1751 : * @brief Validate notBefore timestamp of a certificate (candidateCertificate) against validity period of the
1752 : * issuer certificate (issuerCertificate).
1753 : *
1754 : * Errors are:
1755 : * - CHIP_ERROR_CERT_EXPIRED if the candidateCertificate timestamp does not satisfy the issuerCertificate's timestamp.
1756 : * - CHIP_ERROR_INVALID_ARGUMENT when passing an invalid argument.
1757 : * - CHIP_ERROR_INTERNAL on any unexpected crypto or data conversion errors.
1758 : *
1759 : * @param candidateCertificate A DER Certificate ByteSpan those notBefore timestamp to be evaluated.
1760 : * @param issuerCertificate A DER Certificate ByteSpan used to evaluate validity timestamp of the candidateCertificate.
1761 : *
1762 : * @returns a CHIP_ERROR (see above) on failure or CHIP_NO_ERROR otherwise.
1763 : **/
1764 : CHIP_ERROR IsCertificateValidAtIssuance(const ByteSpan & candidateCertificate, const ByteSpan & issuerCertificate);
1765 :
1766 : /**
1767 : * @brief Validate a certificate's validity date against current time.
1768 : *
1769 : * Errors are:
1770 : * - CHIP_ERROR_CERT_EXPIRED if the certificate has expired.
1771 : * - CHIP_ERROR_INVALID_ARGUMENT when passing an invalid argument.
1772 : * - CHIP_ERROR_INTERNAL on any unexpected crypto or data conversion errors.
1773 : *
1774 : * @param certificate A DER Certificate ByteSpan used as the validity reference to be checked against current time.
1775 : *
1776 : * @returns a CHIP_ERROR (see above) on failure or CHIP_NO_ERROR otherwise.
1777 : **/
1778 : CHIP_ERROR IsCertificateValidAtCurrentTime(const ByteSpan & certificate);
1779 :
1780 : CHIP_ERROR ExtractPubkeyFromX509Cert(const ByteSpan & certificate, Crypto::P256PublicKey & pubkey);
1781 :
1782 : /**
1783 : * @brief Extracts the Subject Key Identifier from an X509 Certificate.
1784 : **/
1785 : CHIP_ERROR ExtractSKIDFromX509Cert(const ByteSpan & certificate, MutableByteSpan & skid);
1786 :
1787 : /**
1788 : * @brief Extracts the Authority Key Identifier from an X509 Certificate.
1789 : **/
1790 : CHIP_ERROR ExtractAKIDFromX509Cert(const ByteSpan & certificate, MutableByteSpan & akid);
1791 :
1792 : /**
1793 : * @brief Extracts the CRL Distribution Point (CDP) extension from an X509 ASN.1 Encoded Certificate.
1794 : * The returned value only covers the URI of the CDP. Only a single URI distribution point
1795 : * GeneralName is supported, and only those that start with "http://" and "https://".
1796 : *
1797 : * @returns CHIP_ERROR_NOT_FOUND if not found or wrong format.
1798 : * CHIP_NO_ERROR otherwise.
1799 : **/
1800 : CHIP_ERROR ExtractCRLDistributionPointURIFromX509Cert(const ByteSpan & certificate, MutableCharSpan & cdpurl);
1801 :
1802 : /**
1803 : * @brief Extracts the CRL Distribution Point (CDP) extension's cRLIssuer Name from an X509 ASN.1 Encoded Certificate.
1804 : * The value is copied into buffer in a raw ASN.1 X.509 format. This format should be directly comparable
1805 : * with the result of ExtractSubjectFromX509Cert().
1806 : *
1807 : * @returns CHIP_ERROR_NOT_FOUND if not found or wrong format.
1808 : * CHIP_NO_ERROR otherwise.
1809 : **/
1810 : CHIP_ERROR ExtractCDPExtensionCRLIssuerFromX509Cert(const ByteSpan & certificate, MutableByteSpan & crlIssuer);
1811 :
1812 : /**
1813 : * @brief Extracts Serial Number from X509 Certificate.
1814 : **/
1815 : CHIP_ERROR ExtractSerialNumberFromX509Cert(const ByteSpan & certificate, MutableByteSpan & serialNumber);
1816 :
1817 : /**
1818 : * @brief Extracts Subject Distinguished Name from X509 Certificate. The value is copied into buffer in a raw ASN.1 X.509 format.
1819 : **/
1820 : CHIP_ERROR ExtractSubjectFromX509Cert(const ByteSpan & certificate, MutableByteSpan & subject);
1821 :
1822 : /**
1823 : * @brief Extracts Issuer Distinguished Name from X509 Certificate. The value is copied into buffer in a raw ASN.1 X.509 format.
1824 : **/
1825 : CHIP_ERROR ExtractIssuerFromX509Cert(const ByteSpan & certificate, MutableByteSpan & issuer);
1826 :
1827 : class PemEncoder
1828 : {
1829 : public:
1830 : /**
1831 : * @brief Construct a PEM encoder for element type `encodedElement` whose DER data is in `derBytes` span.
1832 : *
1833 : * LIFETIME: both encodedElement and derBytes lifetime must be >= PemEncoder lifetime.
1834 : * PemEncoder references these while processing `NextLine()` calls.
1835 : *
1836 : * @param encodedElement - Element type string to include in header/footer (e.g. "CERTIFICATE"). Caller must provide correct
1837 : * uppercase.
1838 : * @param derBytes - Byte span containing data to encode. May be empty.
1839 : */
1840 8 : explicit PemEncoder(const char * encodedElement, ByteSpan derBytes) : mEncodedElement(encodedElement), mDerBytes(derBytes) {}
1841 :
1842 : // No copies.
1843 : PemEncoder(const PemEncoder &) = delete;
1844 : PemEncoder & operator=(const PemEncoder &) = delete;
1845 :
1846 : /**
1847 : * @brief Returns the pointer to the next null-terminated line of the encoding, or nullptr if done.
1848 : *
1849 : * The returned pointer has the lifetime of this class and during that lifetime will always point
1850 : * to valid memory.
1851 : *
1852 : * When header/footer are written, the heading type (`encodedElement` value) such as
1853 : * `CERTIFICATE` is clamped so that the entire header line with `-----BEGIN ${encodedElement}-----`
1854 : * and footer line with `-----END ${encodedElement}-----` are not wider than 64 bytes. This
1855 : * will not happen in practice with the types of things this is meant to encode.
1856 : *
1857 : * Usage should be in a loop, for example:
1858 : *
1859 : * std::vector<std::string> pemLines;
1860 : *
1861 : * PemEncoder encoder("CERTIFICATE", TestCerts::sTestCert_PAA_FFF1_Cert);
1862 : *
1863 : * const char* line = encoder.NextLine();
1864 : * while (line)
1865 : * {
1866 : * pemLines.push_back(std::string{ line });
1867 : * line = encoder.NextLine();
1868 : * }
1869 : *
1870 : * @return a pointer to the internal line buffer for next line or nullptr when done.
1871 : */
1872 : const char * NextLine();
1873 :
1874 : private:
1875 : static constexpr size_t kNumBytesPerLine = 48u;
1876 : static constexpr size_t kLineBufferSize = 64u + 1u; // PEM expects 64 characters wide and a null terminator at least.
1877 : static_assert(kLineBufferSize == (BASE64_ENCODED_LEN(kNumBytesPerLine) + 1), "Internal incoherence of library configuration!");
1878 :
1879 : enum State : int
1880 : {
1881 : kPrintHeader = 0,
1882 : kPrintBody = 1,
1883 : kPrintFooter = 2,
1884 : kDone = 3,
1885 : };
1886 :
1887 : const char * mEncodedElement; // "CERTIFICATE", "EC PUBLIC KEY", etc. Must be capitalized by caller.
1888 : ByteSpan mDerBytes;
1889 : State mState = State::kPrintHeader;
1890 : size_t mProcessedBytes = 0;
1891 : StringBuilder<kLineBufferSize> mStringBuilder{};
1892 : };
1893 :
1894 : // Utility class to take subject Key IDs (AKID/SKID) and convert them to DCL format ("A5:FF:00.....:DE:AD").
1895 : class KeyIdStringifier
1896 : {
1897 : public:
1898 10 : KeyIdStringifier() = default;
1899 :
1900 : /**
1901 : * @brief Returns the null-terminated string buffer owned by the class containing converted KeyID.
1902 : *
1903 : * LIFETIME NOTE: The last returned value from KeyIdToHex is valid until the next call.
1904 : *
1905 : * This is optimized for standard 20-byte AKID/SKID but works for any length, truncating very long ones.
1906 : *
1907 : * @param keyIdBuffer - buffer of bytes of the key ID.
1908 : * @return pointer to class-owned storage of a null-terminated string in DCL format.
1909 : */
1910 14 : const char * KeyIdToHex(ByteSpan keyIdBuffer)
1911 : {
1912 14 : mStringBuilder.Reset();
1913 14 : if (keyIdBuffer.empty())
1914 : {
1915 1 : mStringBuilder.Add("<EMPTY KEY ID>");
1916 1 : return mStringBuilder.c_str();
1917 : }
1918 :
1919 13 : mStringBuilder.AddFormat("%02X", keyIdBuffer[0]);
1920 228 : for (size_t i = 1; i < keyIdBuffer.size(); ++i)
1921 : {
1922 215 : mStringBuilder.Add(":");
1923 215 : mStringBuilder.AddFormat("%02X", keyIdBuffer[i]);
1924 : }
1925 :
1926 13 : return mStringBuilder.AddMarkerIfOverflow().c_str();
1927 : }
1928 :
1929 : private:
1930 : StringBuilder<(Crypto::kAuthorityKeyIdentifierLength * 3) + 1> mStringBuilder;
1931 : };
1932 :
1933 : /**
1934 : * @brief Checks for resigned version of the certificate in the list and returns it.
1935 : *
1936 : * The following conditions SHOULD be satisfied for the certificate to qualify as
1937 : * a resigned version of a reference certificate:
1938 : * - SKID of the candidate and the reference certificate should match.
1939 : * - SubjectDN of the candidate and the reference certificate should match.
1940 : *
1941 : * If no resigned version is found then reference certificate itself is returned.
1942 : *
1943 : * @param referenceCertificate A DER certificate.
1944 : * @param candidateCertificates A pointer to the list of DER Certificates, which should be searched
1945 : * for the resigned version of `referenceCertificate`.
1946 : * @param candidateCertificatesCount Number of certificates in the `candidateCertificates` list.
1947 : * @param outCertificate A reference to the certificate or it's resigned version if found.
1948 : * Note that it points to either `referenceCertificate` or one of
1949 : * `candidateCertificates`, but it doesn't copy data.
1950 : *
1951 : * @returns error if there is certificate parsing/format issue or CHIP_NO_ERROR otherwise.
1952 : **/
1953 : CHIP_ERROR ReplaceCertIfResignedCertFound(const ByteSpan & referenceCertificate, const ByteSpan * candidateCertificates,
1954 : size_t candidateCertificatesCount, ByteSpan & outCertificate);
1955 :
1956 : /**
1957 : * Defines DN attribute types that can include endocing of VID/PID parameters.
1958 : */
1959 : enum class DNAttrType
1960 : {
1961 : kUnspecified = 0,
1962 : kCommonName = 1,
1963 : kMatterVID = 2,
1964 : kMatterPID = 3,
1965 : };
1966 :
1967 : /**
1968 : * @struct AttestationCertVidPid
1969 : *
1970 : * @brief
1971 : * A data structure representing Attestation Certificate VID and PID attributes.
1972 : */
1973 : struct AttestationCertVidPid
1974 : {
1975 : Optional<VendorId> mVendorId;
1976 : Optional<uint16_t> mProductId;
1977 :
1978 693 : bool Initialized() const { return (mVendorId.HasValue() || mProductId.HasValue()); }
1979 : };
1980 :
1981 : /**
1982 : * @brief Extracts VID and PID attributes from the DN Attribute string.
1983 : * If attribute is not present the corresponding output value stays uninitialized.
1984 : *
1985 : * @return CHIP_ERROR_INVALID_ARGUMENT if wrong input is provided.
1986 : * CHIP_ERROR_WRONG_CERT_DN if encoding of kMatterVID and kMatterPID attributes is wrong.
1987 : * CHIP_NO_ERROR otherwise.
1988 : **/
1989 : CHIP_ERROR ExtractVIDPIDFromAttributeString(DNAttrType attrType, const ByteSpan & attr,
1990 : AttestationCertVidPid & vidpidFromMatterAttr, AttestationCertVidPid & vidpidFromCNAttr);
1991 :
1992 : /**
1993 : * @brief Extracts VID and PID attributes from the Subject DN of an X509 Certificate.
1994 : * If attribute is not present the corresponding output value stays uninitialized.
1995 : **/
1996 : CHIP_ERROR ExtractVIDPIDFromX509Cert(const ByteSpan & x509Cert, AttestationCertVidPid & vidpid);
1997 :
1998 : /**
1999 : * @brief The set of credentials needed to operate group message security with symmetric keys.
2000 : */
2001 : typedef struct GroupOperationalCredentials
2002 : {
2003 : /// Validity start time in microseconds since 2000-01-01T00:00:00 UTC ("the Epoch")
2004 : uint64_t start_time;
2005 : /// Session Id
2006 : uint16_t hash;
2007 : /// Operational group key
2008 : uint8_t encryption_key[Crypto::CHIP_CRYPTO_SYMMETRIC_KEY_LENGTH_BYTES];
2009 : /// Privacy key
2010 : uint8_t privacy_key[Crypto::CHIP_CRYPTO_SYMMETRIC_KEY_LENGTH_BYTES];
2011 : } GroupOperationalCredentials;
2012 :
2013 : /**
2014 : * @brief Opaque context used to protect a symmetric key. The key operations must
2015 : * be performed without exposing the protected key value.
2016 : */
2017 : class SymmetricKeyContext
2018 : {
2019 : public:
2020 : /**
2021 : * @brief Returns the symmetric key hash
2022 : *
2023 : * TODO: Replace GetKeyHash() with DeriveGroupSessionId(SymmetricKeyContext &, uint16_t & session_id)
2024 : *
2025 : * @return Group Key Hash
2026 : */
2027 : virtual uint16_t GetKeyHash() = 0;
2028 :
2029 11 : virtual ~SymmetricKeyContext() = default;
2030 : /**
2031 : * @brief Perform the message encryption as described in 4.7.2. (Security Processing of Outgoing Messages)
2032 : * @param[in] plaintext Outgoing message payload.
2033 : * @param[in] aad Additional data (message header contents)
2034 : * @param[in] nonce Nonce (Security Flags | Message Counter | Source Node ID)
2035 : * @param[out] mic Outgoing Message Integrity Check
2036 : * @param[out] ciphertext Outgoing encrypted payload. Must be at least as big as plaintext. The same buffer may be used both
2037 : * for ciphertext, and plaintext.
2038 : * @return CHIP_ERROR
2039 : */
2040 : virtual CHIP_ERROR MessageEncrypt(const ByteSpan & plaintext, const ByteSpan & aad, const ByteSpan & nonce,
2041 : MutableByteSpan & mic, MutableByteSpan & ciphertext) const = 0;
2042 : /**
2043 : * @brief Perform the message decryption as described in 4.7.3.(Security Processing of Incoming Messages)
2044 : * @param[in] ciphertext Incoming encrypted payload
2045 : * @param[in] aad Additional data (message header contents)
2046 : * @param[in] nonce Nonce (Security Flags | Message Counter | Source Node ID)
2047 : * @param[in] mic Incoming Message Integrity Check
2048 : * @param[out] plaintext Incoming message payload. Must be at least as big as ciphertext. The same buffer may be used both
2049 : * for plaintext, and ciphertext.
2050 : * @return CHIP_ERROR
2051 : */
2052 : virtual CHIP_ERROR MessageDecrypt(const ByteSpan & ciphertext, const ByteSpan & aad, const ByteSpan & nonce,
2053 : const ByteSpan & mic, MutableByteSpan & plaintext) const = 0;
2054 :
2055 : /**
2056 : * @brief Perform privacy encoding as described in 4.8.2. (Privacy Processing of Outgoing Messages)
2057 : * @param[in] input Message header to privacy encrypt
2058 : * @param[in] nonce Privacy Nonce = session_id | mic
2059 : * @param[out] output Message header obfuscated
2060 : * @return CHIP_ERROR
2061 : */
2062 : virtual CHIP_ERROR PrivacyEncrypt(const ByteSpan & input, const ByteSpan & nonce, MutableByteSpan & output) const = 0;
2063 :
2064 : /**
2065 : * @brief Perform privacy decoding as described in 4.8.3. (Privacy Processing of Incoming Messages)
2066 : * @param[in] input Message header to privacy decrypt
2067 : * @param[in] nonce Privacy Nonce = session_id | mic
2068 : * @param[out] output Message header deobfuscated
2069 : * @return CHIP_ERROR
2070 : */
2071 : virtual CHIP_ERROR PrivacyDecrypt(const ByteSpan & input, const ByteSpan & nonce, MutableByteSpan & output) const = 0;
2072 :
2073 : /**
2074 : * @brief Release resources such as dynamic memory used to allocate this instance of the SymmetricKeyContext
2075 : */
2076 : virtual void Release() = 0;
2077 : };
2078 :
2079 : /**
2080 : * @brief Derives the Operational Group Key using the Key Derivation Function (KDF) from the given epoch key.
2081 : * @param[in] epoch_key The epoch key. Must be CHIP_CRYPTO_SYMMETRIC_KEY_LENGTH_BYTES bytes length.
2082 : * @param[in] compressed_fabric_id The compressed fabric ID for the fabric (big endian byte string)
2083 : * @param[out] out_key Symmetric key used as the encryption key during message processing for group communication.
2084 : The buffer size must be at least CHIP_CRYPTO_SYMMETRIC_KEY_LENGTH_BYTES bytes length.
2085 : * @return Returns a CHIP_NO_ERROR on succcess, or CHIP_ERROR_INTERNAL if the provided key is invalid.
2086 : **/
2087 : CHIP_ERROR DeriveGroupOperationalKey(const ByteSpan & epoch_key, const ByteSpan & compressed_fabric_id, MutableByteSpan & out_key);
2088 :
2089 : /**
2090 : * @brief Derives the Group Session ID from a given operational group key using
2091 : * the Key Derivation Function (Group Key Hash)
2092 : * @param[in] operational_key The operational group key. Must be CHIP_CRYPTO_SYMMETRIC_KEY_LENGTH_BYTES bytes length.
2093 : * @param[out] session_id Output of the Group Key Hash
2094 : * @return Returns a CHIP_NO_ERROR on succcess, or CHIP_ERROR_INVALID_ARGUMENT if the provided key is invalid.
2095 : **/
2096 : CHIP_ERROR DeriveGroupSessionId(const ByteSpan & operational_key, uint16_t & session_id);
2097 :
2098 : /**
2099 : * @brief Derives the Privacy Group Key using the Key Derivation Function (KDF) from the given epoch key.
2100 : * @param[in] epoch_key The epoch key. Must be CHIP_CRYPTO_SYMMETRIC_KEY_LENGTH_BYTES bytes length.
2101 : * @param[out] out_key Symmetric key used as the privacy key during message processing for group communication.
2102 : * The buffer size must be at least CHIP_CRYPTO_SYMMETRIC_KEY_LENGTH_BYTES bytes length.
2103 : * @return Returns a CHIP_NO_ERROR on succcess, or CHIP_ERROR_INTERNAL if the provided key is invalid.
2104 : **/
2105 : CHIP_ERROR DeriveGroupPrivacyKey(const ByteSpan & epoch_key, MutableByteSpan & out_key);
2106 :
2107 : /**
2108 : * @brief Derives the complete set of credentials needed for group security.
2109 : *
2110 : * This function will derive the Encryption Key, Group Key Hash (Session Id), and Privacy Key
2111 : * for the given Epoch Key and Compressed Fabric Id.
2112 : * @param[in] epoch_key The epoch key. Must be CHIP_CRYPTO_SYMMETRIC_KEY_LENGTH_BYTES bytes length.
2113 : * @param[in] compressed_fabric_id The compressed fabric ID for the fabric (big endian byte string)
2114 : * @param[out] operational_credentials The set of Symmetric keys used during message processing for group communication.
2115 : * @return Returns a CHIP_NO_ERROR on succcess, or CHIP_ERROR_INTERNAL if the provided key is invalid.
2116 : **/
2117 : CHIP_ERROR DeriveGroupOperationalCredentials(const ByteSpan & epoch_key, const ByteSpan & compressed_fabric_id,
2118 : GroupOperationalCredentials & operational_credentials);
2119 : } // namespace Crypto
2120 : } // namespace chip
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