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/BufferReader.h>
36 : #include <lib/support/CodeUtils.h>
37 : #include <lib/support/SafePointerCast.h>
38 : #include <lib/support/Span.h>
39 :
40 : #include <stddef.h>
41 : #include <string.h>
42 :
43 : namespace chip {
44 : namespace Crypto {
45 :
46 : inline constexpr size_t kMax_x509_Certificate_Length = 600;
47 :
48 : inline constexpr size_t kP256_FE_Length = 32;
49 : inline constexpr size_t kP256_ECDSA_Signature_Length_Raw = (2 * kP256_FE_Length);
50 : inline constexpr size_t kP256_Point_Length = (2 * kP256_FE_Length + 1);
51 : inline constexpr size_t kSHA256_Hash_Length = 32;
52 : inline constexpr size_t kSHA1_Hash_Length = 20;
53 : inline constexpr size_t kSubjectKeyIdentifierLength = kSHA1_Hash_Length;
54 : inline constexpr size_t kAuthorityKeyIdentifierLength = kSHA1_Hash_Length;
55 : inline constexpr size_t kMaxCertificateSerialNumberLength = 20;
56 : inline constexpr size_t kMaxCertificateDistinguishedNameLength = 200;
57 : inline constexpr size_t kMaxCRLDistributionPointURLLength = 100;
58 :
59 : inline constexpr char kValidCDPURIHttpPrefix[] = "http://";
60 : inline constexpr char kValidCDPURIHttpsPrefix[] = "https://";
61 :
62 : inline constexpr size_t CHIP_CRYPTO_GROUP_SIZE_BYTES = kP256_FE_Length;
63 : inline constexpr size_t CHIP_CRYPTO_PUBLIC_KEY_SIZE_BYTES = kP256_Point_Length;
64 :
65 : inline constexpr size_t CHIP_CRYPTO_AEAD_MIC_LENGTH_BYTES = 16;
66 : inline constexpr size_t CHIP_CRYPTO_SYMMETRIC_KEY_LENGTH_BYTES = 16;
67 :
68 : inline constexpr size_t kMax_ECDH_Secret_Length = kP256_FE_Length;
69 : inline constexpr size_t kMax_ECDSA_Signature_Length = kP256_ECDSA_Signature_Length_Raw;
70 : inline constexpr size_t kMAX_FE_Length = kP256_FE_Length;
71 : inline constexpr size_t kMAX_Point_Length = kP256_Point_Length;
72 : inline constexpr size_t kMAX_Hash_Length = kSHA256_Hash_Length;
73 :
74 : // Minimum required CSR length buffer length is relatively small since it's a single
75 : // P256 key and no metadata/extensions are expected to be honored by the CA.
76 : inline constexpr size_t kMIN_CSR_Buffer_Size = 255;
77 :
78 : [[deprecated("This constant is no longer used by common code and should be replaced by kMIN_CSR_Buffer_Size. Checks that a CSR is "
79 : "<= kMAX_CSR_Buffer_size must be updated. This remains to keep valid buffers working from previous public API "
80 : "usage.")]] constexpr size_t kMAX_CSR_Buffer_Size = 255;
81 :
82 : inline constexpr size_t CHIP_CRYPTO_HASH_LEN_BYTES = kSHA256_Hash_Length;
83 :
84 : inline constexpr size_t kSpake2p_Min_PBKDF_Salt_Length = 16;
85 : inline constexpr size_t kSpake2p_Max_PBKDF_Salt_Length = 32;
86 : inline constexpr uint32_t kSpake2p_Min_PBKDF_Iterations = 1000;
87 : inline constexpr uint32_t kSpake2p_Max_PBKDF_Iterations = 100000;
88 :
89 : inline constexpr size_t kP256_PrivateKey_Length = CHIP_CRYPTO_GROUP_SIZE_BYTES;
90 : inline constexpr size_t kP256_PublicKey_Length = CHIP_CRYPTO_PUBLIC_KEY_SIZE_BYTES;
91 :
92 : inline constexpr size_t kAES_CCM128_Key_Length = 128u / 8u;
93 : inline constexpr size_t kAES_CCM128_Block_Length = kAES_CCM128_Key_Length;
94 : inline constexpr size_t kAES_CCM128_Nonce_Length = 13;
95 : inline constexpr size_t kAES_CCM128_Tag_Length = 16;
96 : inline constexpr size_t kHMAC_CCM128_Key_Length = 128u / 8u;
97 :
98 : inline constexpr size_t CHIP_CRYPTO_AEAD_NONCE_LENGTH_BYTES = kAES_CCM128_Nonce_Length;
99 :
100 : /* These sizes are hardcoded here to remove header dependency on underlying crypto library
101 : * in a public interface file. The validity of these sizes is verified by static_assert in
102 : * the implementation files.
103 : */
104 : inline constexpr size_t kMAX_Spake2p_Context_Size = 1024;
105 : inline constexpr size_t kMAX_P256Keypair_Context_Size = 512;
106 :
107 : inline constexpr size_t kEmitDerIntegerWithoutTagOverhead = 1; // 1 sign stuffer
108 : inline constexpr size_t kEmitDerIntegerOverhead = 3; // Tag + Length byte + 1 sign stuffer
109 :
110 : inline constexpr size_t kMAX_Hash_SHA256_Context_Size = CHIP_CONFIG_SHA256_CONTEXT_SIZE;
111 :
112 : inline constexpr size_t kSpake2p_WS_Length = kP256_FE_Length + 8;
113 : inline constexpr size_t kSpake2p_VerifierSerialized_Length = kP256_FE_Length + kP256_Point_Length;
114 :
115 : inline constexpr char kVIDPrefixForCNEncoding[] = "Mvid:";
116 : inline constexpr char kPIDPrefixForCNEncoding[] = "Mpid:";
117 : inline constexpr size_t kVIDandPIDHexLength = sizeof(uint16_t) * 2;
118 : inline constexpr size_t kMax_CommonNameAttr_Length = 64;
119 :
120 : enum class FabricBindingVersion : uint8_t
121 : {
122 : kVersion1 = 0x01 // Initial version using version 1.0 of the Matter Cryptographic Primitives.
123 : };
124 :
125 : // VidVerificationStatementVersion is on purpose different and non-overlapping with FabricBindingVersion.
126 : enum class VidVerificationStatementVersion : uint8_t
127 : {
128 : kVersion1 = 0x21 // Initial version using version 1.0 of the Matter Cryptographic Primitives.
129 : };
130 :
131 : inline constexpr uint8_t kFabricBindingVersionV1 = 1u;
132 :
133 : inline constexpr size_t kVendorIdVerificationClientChallengeSize = 32u;
134 :
135 : // VIDVerificationStatement := statement_version || vid_verification_signer_skid || vid_verification_statement_signature
136 : inline constexpr size_t kVendorIdVerificationStatementV1Size =
137 : sizeof(uint8_t) + kSubjectKeyIdentifierLength + kP256_ECDSA_Signature_Length_Raw;
138 : static_assert(
139 : kVendorIdVerificationStatementV1Size == 85,
140 : "Expected size of VendorIdVerificationStatement version 1 was computed incorrectly due to changes of fundamental constants");
141 :
142 : // vendor_fabric_binding_message := fabric_binding_version (1 byte) || root_public_key || fabric_id || vendor_id
143 : inline constexpr size_t kVendorFabricBindingMessageV1Size =
144 : sizeof(uint8_t) + CHIP_CRYPTO_PUBLIC_KEY_SIZE_BYTES + sizeof(uint64_t) + sizeof(uint16_t);
145 : static_assert(
146 : kVendorFabricBindingMessageV1Size == 76,
147 : "Expected size of VendorFabricBindingMessage version 1 was computed incorrectly due to changes of fundamental constants");
148 :
149 : // vendor_id_verification_tbs := fabric_binding_version || client_challenge || attestation_challenge || fabric_index ||
150 : // vendor_fabric_binding_message || <vid_verification_statement>
151 : inline constexpr size_t kVendorIdVerificationTbsV1MaxSize = sizeof(uint8_t) + kVendorIdVerificationClientChallengeSize +
152 : CHIP_CRYPTO_SYMMETRIC_KEY_LENGTH_BYTES + sizeof(uint8_t) + kVendorFabricBindingMessageV1Size +
153 : kVendorIdVerificationStatementV1Size;
154 :
155 : /*
156 : * Overhead to encode a raw ECDSA signature in X9.62 format in ASN.1 DER
157 : *
158 : * Ecdsa-Sig-Value ::= SEQUENCE {
159 : * r INTEGER,
160 : * s INTEGER
161 : * }
162 : *
163 : * --> SEQUENCE, universal constructed tag (0x30), length over 2 bytes, up to 255 (to support future larger sizes up to 512 bits)
164 : * -> SEQ_OVERHEAD = 3 bytes
165 : * --> INTEGER, universal primitive tag (0x02), length over 1 byte, one extra byte worst case
166 : * over max for 0x00 when MSB is set.
167 : * -> INT_OVERHEAD = 3 bytes
168 : *
169 : * There is 1 sequence of 2 integers. Overhead is SEQ_OVERHEAD + (2 * INT_OVERHEAD) = 3 + (2 * 3) = 9.
170 : */
171 : inline constexpr size_t kMax_ECDSA_X9Dot62_Asn1_Overhead = 9;
172 : inline constexpr size_t kMax_ECDSA_Signature_Length_Der = kMax_ECDSA_Signature_Length + kMax_ECDSA_X9Dot62_Asn1_Overhead;
173 :
174 : static_assert(kMax_ECDH_Secret_Length >= kP256_FE_Length, "ECDH shared secret is too short for crypto suite");
175 : static_assert(kMax_ECDSA_Signature_Length >= kP256_ECDSA_Signature_Length_Raw,
176 : "ECDSA signature buffer length is too short for crypto suite");
177 :
178 : inline constexpr size_t kCompressedFabricIdentifierSize = 8;
179 :
180 : /**
181 : * Spake2+ parameters for P256
182 : * Defined in https://www.ietf.org/id/draft-bar-cfrg-spake2plus-01.html#name-ciphersuites
183 : */
184 : const uint8_t spake2p_M_p256[] = {
185 : 0x04, 0x88, 0x6e, 0x2f, 0x97, 0xac, 0xe4, 0x6e, 0x55, 0xba, 0x9d, 0xd7, 0x24, 0x25, 0x79, 0xf2, 0x99,
186 : 0x3b, 0x64, 0xe1, 0x6e, 0xf3, 0xdc, 0xab, 0x95, 0xaf, 0xd4, 0x97, 0x33, 0x3d, 0x8f, 0xa1, 0x2f, 0x5f,
187 : 0xf3, 0x55, 0x16, 0x3e, 0x43, 0xce, 0x22, 0x4e, 0x0b, 0x0e, 0x65, 0xff, 0x02, 0xac, 0x8e, 0x5c, 0x7b,
188 : 0xe0, 0x94, 0x19, 0xc7, 0x85, 0xe0, 0xca, 0x54, 0x7d, 0x55, 0xa1, 0x2e, 0x2d, 0x20,
189 : };
190 : const uint8_t spake2p_N_p256[] = {
191 : 0x04, 0xd8, 0xbb, 0xd6, 0xc6, 0x39, 0xc6, 0x29, 0x37, 0xb0, 0x4d, 0x99, 0x7f, 0x38, 0xc3, 0x77, 0x07,
192 : 0x19, 0xc6, 0x29, 0xd7, 0x01, 0x4d, 0x49, 0xa2, 0x4b, 0x4f, 0x98, 0xba, 0xa1, 0x29, 0x2b, 0x49, 0x07,
193 : 0xd6, 0x0a, 0xa6, 0xbf, 0xad, 0xe4, 0x50, 0x08, 0xa6, 0x36, 0x33, 0x7f, 0x51, 0x68, 0xc6, 0x4d, 0x9b,
194 : 0xd3, 0x60, 0x34, 0x80, 0x8c, 0xd5, 0x64, 0x49, 0x0b, 0x1e, 0x65, 0x6e, 0xdb, 0xe7,
195 : };
196 :
197 : /**
198 : * Spake2+ state machine to ensure proper execution of the protocol.
199 : */
200 : enum class CHIP_SPAKE2P_STATE : uint8_t
201 : {
202 : PREINIT = 0, // Before any initialization
203 : INIT, // First initialization
204 : STARTED, // Prover & Verifier starts
205 : R1, // Round one complete
206 : R2, // Round two complete
207 : KC, // Key confirmation complete
208 : };
209 :
210 : /**
211 : * Spake2+ role.
212 : */
213 : enum class CHIP_SPAKE2P_ROLE : uint8_t
214 : {
215 : VERIFIER = 0, // Accessory
216 : PROVER = 1, // Commissioner
217 : };
218 :
219 : enum class SupportedECPKeyTypes : uint8_t
220 : {
221 : ECP256R1 = 0,
222 : };
223 :
224 : enum class ECPKeyTarget : uint8_t
225 : {
226 : ECDH = 0,
227 : ECDSA = 1,
228 : };
229 :
230 : /** @brief Safely clears the first `len` bytes of memory area `buf`.
231 : * @param buf Pointer to a memory buffer holding secret data that must be cleared.
232 : * @param len Specifies secret data size in bytes.
233 : **/
234 : void ClearSecretData(uint8_t * buf, size_t len);
235 :
236 : /**
237 : * Helper for clearing a C array which auto-deduces the size.
238 : */
239 : template <size_t N>
240 413373 : void ClearSecretData(uint8_t (&buf)[N])
241 : {
242 413373 : ClearSecretData(buf, N);
243 413373 : }
244 :
245 : /**
246 : * @brief Constant-time buffer comparison
247 : *
248 : * This function implements constant time memcmp. It's good practice
249 : * to use constant time functions for cryptographic functions.
250 : *
251 : * @param a Pointer to first buffer
252 : * @param b Pointer to Second buffer
253 : * @param n Number of bytes to compare
254 : * @return true if `n` first bytes of both buffers are equal, false otherwise
255 : */
256 : bool IsBufferContentEqualConstantTime(const void * a, const void * b, size_t n);
257 :
258 : template <typename Sig>
259 : class ECPKey
260 : {
261 : protected:
262 : // This base type can't be copied / assigned directly.
263 : // Sub-types should be either uncopyable or final.
264 0 : ECPKey() = default;
265 : ECPKey(const ECPKey &) = default;
266 1596 : ECPKey & operator=(const ECPKey &) = default;
267 :
268 : public:
269 808 : virtual ~ECPKey() = default;
270 :
271 : virtual SupportedECPKeyTypes Type() const = 0;
272 : virtual size_t Length() const = 0;
273 : virtual bool IsUncompressed() const = 0;
274 : virtual operator const uint8_t *() const = 0;
275 : virtual operator uint8_t *() = 0;
276 : virtual const uint8_t * ConstBytes() const = 0;
277 : virtual uint8_t * Bytes() = 0;
278 :
279 0 : virtual bool Matches(const ECPKey<Sig> & other) const
280 : {
281 0 : return (this->Length() == other.Length()) &&
282 0 : IsBufferContentEqualConstantTime(this->ConstBytes(), other.ConstBytes(), this->Length());
283 : }
284 :
285 : virtual CHIP_ERROR ECDSA_validate_msg_signature(const uint8_t * msg, const size_t msg_length, const Sig & signature) const = 0;
286 : virtual CHIP_ERROR ECDSA_validate_hash_signature(const uint8_t * hash, const size_t hash_length,
287 : const Sig & signature) const = 0;
288 : };
289 :
290 : /**
291 : * @brief Helper class for holding sensitive data that should be erased from memory after use.
292 : *
293 : * The sensitive data buffer is a variable-length, fixed-capacity buffer class that securely erases
294 : * the contents of a buffer when the buffer is destroyed.
295 : */
296 : template <size_t kCapacity>
297 : class SensitiveDataBuffer
298 : {
299 : public:
300 3607 : ~SensitiveDataBuffer()
301 : {
302 : // Sanitize after use
303 3607 : ClearSecretData(mBytes);
304 3607 : }
305 3606 : SensitiveDataBuffer() {}
306 1 : SensitiveDataBuffer(const SensitiveDataBuffer & other) { *this = other; }
307 1 : SensitiveDataBuffer & operator=(const SensitiveDataBuffer & other)
308 : {
309 : // Guard self assignment
310 1 : if (this == &other)
311 0 : return *this;
312 :
313 1 : ClearSecretData(mBytes);
314 1 : SetLength(other.Length());
315 1 : ::memcpy(Bytes(), other.ConstBytes(), other.Length());
316 1 : return *this;
317 : }
318 :
319 : /**
320 : * @brief Set current length of the buffer
321 : * @return Error if new length is exceeds capacity of the buffer
322 : */
323 3479 : CHIP_ERROR SetLength(size_t length)
324 : {
325 3479 : VerifyOrReturnError(length <= kCapacity, CHIP_ERROR_INVALID_ARGUMENT);
326 3479 : mLength = length;
327 3479 : return CHIP_NO_ERROR;
328 : }
329 :
330 : /**
331 : * @brief Returns current length of the buffer
332 : */
333 3687 : size_t Length() const { return mLength; }
334 :
335 : /**
336 : * @brief Returns non-const pointer to start of the underlying buffer
337 : */
338 3841 : uint8_t * Bytes() { return &mBytes[0]; }
339 :
340 : /**
341 : * @brief Returns const pointer to start of the underlying buffer
342 : */
343 6165 : const uint8_t * ConstBytes() const { return &mBytes[0]; }
344 :
345 : /**
346 : * @brief Constructs span from the underlying buffer
347 : */
348 21 : ByteSpan Span() const { return ByteSpan(ConstBytes(), Length()); }
349 :
350 : /**
351 : * @brief Returns capacity of the buffer
352 : */
353 1458 : static constexpr size_t Capacity() { return kCapacity; }
354 :
355 : private:
356 : uint8_t mBytes[kCapacity];
357 : size_t mLength = 0;
358 : };
359 :
360 : /**
361 : * @brief Helper class for holding fixed-sized sensitive data that should be erased from memory after use.
362 : *
363 : * The sensitive data buffer is a fixed-length, fixed-capacity buffer class that securely erases
364 : * the contents of a buffer when the buffer is destroyed.
365 : */
366 : template <size_t kCapacity>
367 : class SensitiveDataFixedBuffer
368 : {
369 : public:
370 : SensitiveDataFixedBuffer() = default;
371 :
372 : constexpr explicit SensitiveDataFixedBuffer(const uint8_t (&rawValue)[kCapacity])
373 : {
374 : memcpy(&mBytes[0], &rawValue[0], kCapacity);
375 : }
376 :
377 0 : constexpr explicit SensitiveDataFixedBuffer(const FixedByteSpan<kCapacity> & value)
378 : {
379 0 : memcpy(&mBytes[0], value.data(), kCapacity);
380 0 : }
381 :
382 135320 : ~SensitiveDataFixedBuffer()
383 : {
384 : // Sanitize after use
385 135320 : ClearSecretData(mBytes);
386 135320 : }
387 :
388 : /**
389 : * @brief Returns fixed length of the buffer
390 : */
391 : constexpr size_t Length() const { return kCapacity; }
392 :
393 : /**
394 : * @brief Returns non-const pointer to start of the underlying buffer
395 : */
396 1545 : uint8_t * Bytes() { return &mBytes[0]; }
397 :
398 : /**
399 : * @brief Returns const pointer to start of the underlying buffer
400 : */
401 : const uint8_t * ConstBytes() const { return &mBytes[0]; }
402 :
403 : /**
404 : * @brief Constructs fixed span from the underlying buffer
405 : */
406 0 : FixedByteSpan<kCapacity> Span() const { return FixedByteSpan<kCapacity>(mBytes); }
407 :
408 : /**
409 : * @brief Returns capacity of the buffer
410 : */
411 1530 : static constexpr size_t Capacity() { return kCapacity; }
412 :
413 : private:
414 : uint8_t mBytes[kCapacity];
415 : };
416 :
417 : using P256ECDSASignature = SensitiveDataBuffer<kMax_ECDSA_Signature_Length>;
418 : using P256ECDHDerivedSecret = SensitiveDataBuffer<kMax_ECDH_Secret_Length>;
419 :
420 : using IdentityProtectionKey = SensitiveDataFixedBuffer<CHIP_CRYPTO_SYMMETRIC_KEY_LENGTH_BYTES>;
421 : using IdentityProtectionKeySpan = FixedByteSpan<Crypto::CHIP_CRYPTO_SYMMETRIC_KEY_LENGTH_BYTES>;
422 :
423 : using AttestationChallenge = SensitiveDataFixedBuffer<CHIP_CRYPTO_SYMMETRIC_KEY_LENGTH_BYTES>;
424 :
425 : class P256PublicKey final // final due to being copyable
426 : : public ECPKey<P256ECDSASignature>
427 : {
428 : public:
429 0 : P256PublicKey() = default;
430 :
431 : template <size_t N>
432 : constexpr P256PublicKey(const uint8_t (&raw_value)[N])
433 : {
434 : static_assert(N == kP256_PublicKey_Length, "Can only array-initialize from proper bounds");
435 : memcpy(&bytes[0], &raw_value[0], N);
436 : }
437 :
438 : template <size_t N>
439 727 : constexpr P256PublicKey(const FixedByteSpan<N> & value)
440 727 : {
441 : static_assert(N == kP256_PublicKey_Length, "Can only initialize from proper sized byte span");
442 727 : memcpy(&bytes[0], value.data(), N);
443 727 : }
444 :
445 : template <size_t N>
446 929 : P256PublicKey & operator=(const FixedByteSpan<N> & value)
447 : {
448 : static_assert(N == kP256_PublicKey_Length, "Can only initialize from proper sized byte span");
449 929 : memcpy(&bytes[0], value.data(), N);
450 929 : return *this;
451 : }
452 :
453 4161 : SupportedECPKeyTypes Type() const override { return SupportedECPKeyTypes::ECP256R1; }
454 14214 : size_t Length() const override { return kP256_PublicKey_Length; }
455 5504 : operator uint8_t *() override { return bytes; }
456 3279 : operator const uint8_t *() const override { return bytes; }
457 3154 : const uint8_t * ConstBytes() const override { return &bytes[0]; }
458 16 : uint8_t * Bytes() override { return &bytes[0]; }
459 797 : bool IsUncompressed() const override
460 : {
461 797 : constexpr uint8_t kUncompressedPointMarker = 0x04;
462 : // SEC1 definition of an uncompressed point is (0x04 || X || Y) where X and Y are
463 : // raw zero-padded big-endian large integers of the group size.
464 797 : return (Length() == ((kP256_FE_Length * 2) + 1)) && (ConstBytes()[0] == kUncompressedPointMarker);
465 : }
466 :
467 : CHIP_ERROR ECDSA_validate_msg_signature(const uint8_t * msg, size_t msg_length,
468 : const P256ECDSASignature & signature) const override;
469 : CHIP_ERROR ECDSA_validate_hash_signature(const uint8_t * hash, size_t hash_length,
470 : const P256ECDSASignature & signature) const override;
471 :
472 : private:
473 : uint8_t bytes[kP256_PublicKey_Length];
474 : };
475 :
476 : template <typename PK, typename Secret, typename Sig>
477 : class ECPKeypair
478 : {
479 : protected:
480 : // This base type can't be copied / assigned directly.
481 : // Sub-types should be either uncopyable or final.
482 1401 : ECPKeypair() = default;
483 : ECPKeypair(const ECPKeypair &) = default;
484 : ECPKeypair & operator=(const ECPKeypair &) = default;
485 :
486 : public:
487 1726 : virtual ~ECPKeypair() = default;
488 :
489 : /** @brief Generate a new Certificate Signing Request (CSR).
490 : * @param csr Newly generated CSR in DER format
491 : * @param csr_length The caller provides the length of input buffer (csr). The function returns the actual length of generated
492 : *CSR.
493 : * @return Returns a CHIP_ERROR on error, CHIP_NO_ERROR otherwise
494 : **/
495 : virtual CHIP_ERROR NewCertificateSigningRequest(uint8_t * csr, size_t & csr_length) const = 0;
496 :
497 : /**
498 : * @brief A function to sign a msg using ECDSA
499 : * @param msg Message that needs to be signed
500 : * @param msg_length Length of message
501 : * @param out_signature Buffer that will hold the output signature. The signature consists of: 2 EC elements (r and s),
502 : * in raw <r,s> point form (see SEC1).
503 : * @return Returns a CHIP_ERROR on error, CHIP_NO_ERROR otherwise
504 : **/
505 : virtual CHIP_ERROR ECDSA_sign_msg(const uint8_t * msg, size_t msg_length, Sig & out_signature) const = 0;
506 :
507 : /** @brief A function to derive a shared secret using ECDH
508 : * @param remote_public_key Public key of remote peer with which we are trying to establish secure channel. remote_public_key is
509 : * ASN.1 DER encoded as padded big-endian field elements as described in SEC 1: Elliptic Curve Cryptography
510 : * [https://www.secg.org/sec1-v2.pdf]
511 : * @param out_secret Buffer to write out secret into. This is a byte array representing the x coordinate of the shared secret.
512 : * @return Returns a CHIP_ERROR on error, CHIP_NO_ERROR otherwise
513 : **/
514 : virtual CHIP_ERROR ECDH_derive_secret(const PK & remote_public_key, Secret & out_secret) const = 0;
515 :
516 : virtual const PK & Pubkey() const = 0;
517 : };
518 :
519 : struct alignas(size_t) P256KeypairContext
520 : {
521 : uint8_t mBytes[kMAX_P256Keypair_Context_Size];
522 : };
523 :
524 : /**
525 : * A serialized P256 key pair is the concatenation of the public and private keys, in that order.
526 : */
527 : using P256SerializedKeypair = SensitiveDataBuffer<kP256_PublicKey_Length + kP256_PrivateKey_Length>;
528 :
529 : class P256KeypairBase : public ECPKeypair<P256PublicKey, P256ECDHDerivedSecret, P256ECDSASignature>
530 : {
531 : protected:
532 : // This base type can't be copied / assigned directly.
533 : // Sub-types should be either uncopyable or final.
534 1401 : P256KeypairBase() = default;
535 : P256KeypairBase(const P256KeypairBase &) = default;
536 : P256KeypairBase & operator=(const P256KeypairBase &) = default;
537 :
538 : public:
539 : /**
540 : * @brief Initialize the keypair.
541 : * @return Returns a CHIP_ERROR on error, CHIP_NO_ERROR otherwise
542 : **/
543 : virtual CHIP_ERROR Initialize(ECPKeyTarget key_target) = 0;
544 :
545 : /**
546 : * @brief Serialize the keypair.
547 : * @return Returns a CHIP_ERROR on error, CHIP_NO_ERROR otherwise
548 : **/
549 : virtual CHIP_ERROR Serialize(P256SerializedKeypair & output) const = 0;
550 :
551 : /**
552 : * @brief Deserialize the keypair.
553 : * @return Returns a CHIP_ERROR on error, CHIP_NO_ERROR otherwise
554 : **/
555 : virtual CHIP_ERROR Deserialize(P256SerializedKeypair & input) = 0;
556 : };
557 :
558 : class P256Keypair : public P256KeypairBase
559 : {
560 : public:
561 1401 : P256Keypair() = default;
562 : ~P256Keypair() override;
563 :
564 : // P256Keypair can't be copied / assigned.
565 : P256Keypair(const P256Keypair &) = delete;
566 : P256Keypair & operator=(const P256Keypair &) = delete;
567 :
568 : /**
569 : * @brief Initialize the keypair.
570 : * @return Returns a CHIP_ERROR on error, CHIP_NO_ERROR otherwise
571 : **/
572 : CHIP_ERROR Initialize(ECPKeyTarget key_target) override;
573 :
574 : /**
575 : * @brief Serialize the keypair.
576 : * @return Returns a CHIP_ERROR on error, CHIP_NO_ERROR otherwise
577 : **/
578 : CHIP_ERROR Serialize(P256SerializedKeypair & output) const override;
579 :
580 : /**
581 : * @brief Deserialize the keypair.
582 : * @return Returns a CHIP_ERROR on error, CHIP_NO_ERROR otherwise
583 : **/
584 : CHIP_ERROR Deserialize(P256SerializedKeypair & input) override;
585 :
586 : /**
587 : * @brief Generate a new Certificate Signing Request (CSR).
588 : * @param csr Newly generated CSR in DER format
589 : * @param csr_length The caller provides the length of input buffer (csr). The function returns the actual length of generated
590 : *CSR.
591 : * @return Returns a CHIP_ERROR on error, CHIP_NO_ERROR otherwise
592 : **/
593 : CHIP_ERROR NewCertificateSigningRequest(uint8_t * csr, size_t & csr_length) const override;
594 :
595 : /**
596 : * @brief A function to sign a msg using ECDSA
597 : * @param msg Message that needs to be signed
598 : * @param msg_length Length of message
599 : * @param out_signature Buffer that will hold the output signature. The signature consists of: 2 EC elements (r and s),
600 : * in raw <r,s> point form (see SEC1).
601 : * @return Returns a CHIP_ERROR on error, CHIP_NO_ERROR otherwise
602 : **/
603 : CHIP_ERROR ECDSA_sign_msg(const uint8_t * msg, size_t msg_length, P256ECDSASignature & out_signature) const override;
604 :
605 : /**
606 : * @brief A function to derive a shared secret using ECDH
607 : *
608 : * This implements the CHIP_Crypto_ECDH(PrivateKey myPrivateKey, PublicKey theirPublicKey) cryptographic primitive
609 : * from the specification, using this class's private key from `mKeypair` as `myPrivateKey` and the remote
610 : * public key from `remote_public_key` as `theirPublicKey`.
611 : *
612 : * @param remote_public_key Public key of remote peer with which we are trying to establish secure channel. remote_public_key is
613 : * ASN.1 DER encoded as padded big-endian field elements as described in SEC 1: Elliptic Curve Cryptography
614 : * [https://www.secg.org/sec1-v2.pdf]
615 : * @param out_secret Buffer to write out secret into. This is a byte array representing the x coordinate of the shared secret.
616 : * @return Returns a CHIP_ERROR on error, CHIP_NO_ERROR otherwise
617 : **/
618 : CHIP_ERROR ECDH_derive_secret(const P256PublicKey & remote_public_key, P256ECDHDerivedSecret & out_secret) const override;
619 :
620 : /** @brief Return public key for the keypair.
621 : **/
622 790 : const P256PublicKey & Pubkey() const override { return mPublicKey; }
623 :
624 : /** Release resources associated with this key pair */
625 : void Clear();
626 :
627 : protected:
628 : P256PublicKey mPublicKey;
629 : mutable P256KeypairContext mKeypair;
630 : bool mInitialized = false;
631 : };
632 :
633 : /**
634 : * @brief Platform-specific symmetric key handle
635 : *
636 : * The class represents a key used by the Matter stack either in the form of raw key material or key
637 : * reference, depending on the platform. To achieve that, it contains an opaque context that can be
638 : * cast to a concrete representation used by the given platform.
639 : *
640 : * @note SymmetricKeyHandle is an abstract class to force child classes for each key handle type.
641 : * SymmetricKeyHandle class implements all the necessary components for handles.
642 : */
643 : template <size_t ContextSize>
644 : class SymmetricKeyHandle
645 : {
646 : public:
647 : SymmetricKeyHandle(const SymmetricKeyHandle &) = delete;
648 : SymmetricKeyHandle(SymmetricKeyHandle &&) = delete;
649 : void operator=(const SymmetricKeyHandle &) = delete;
650 : void operator=(SymmetricKeyHandle &&) = delete;
651 :
652 : /**
653 : * @brief Get internal context cast to the desired key representation
654 : */
655 : template <class T>
656 28305 : const T & As() const
657 : {
658 28305 : return *SafePointerCast<const T *>(&mContext);
659 : }
660 :
661 : /**
662 : * @brief Get internal context cast to the desired, mutable key representation
663 : */
664 : template <class T>
665 7330 : T & AsMutable()
666 : {
667 7330 : return *SafePointerCast<T *>(&mContext);
668 : }
669 :
670 : protected:
671 271154 : SymmetricKeyHandle() = default;
672 271154 : ~SymmetricKeyHandle() { ClearSecretData(mContext.mOpaque); }
673 :
674 : private:
675 : struct alignas(uintptr_t) OpaqueContext
676 : {
677 : uint8_t mOpaque[ContextSize] = {};
678 : } mContext;
679 : };
680 :
681 : using Symmetric128BitsKeyByteArray = uint8_t[CHIP_CRYPTO_SYMMETRIC_KEY_LENGTH_BYTES];
682 :
683 : /**
684 : * @brief Platform-specific 128-bit symmetric key handle
685 : */
686 : class Symmetric128BitsKeyHandle : public SymmetricKeyHandle<CHIP_CRYPTO_SYMMETRIC_KEY_LENGTH_BYTES>
687 : {
688 : };
689 :
690 : /**
691 : * @brief Platform-specific 128-bit AES key handle
692 : */
693 : class Aes128KeyHandle final : public Symmetric128BitsKeyHandle
694 : {
695 : };
696 :
697 : /**
698 : * @brief Platform-specific 128-bit HMAC key handle
699 : */
700 : class Hmac128KeyHandle final : public Symmetric128BitsKeyHandle
701 : {
702 : };
703 :
704 : /**
705 : * @brief Platform-specific HKDF key handle
706 : */
707 : class HkdfKeyHandle final : public SymmetricKeyHandle<CHIP_CONFIG_HKDF_KEY_HANDLE_CONTEXT_SIZE>
708 : {
709 : };
710 :
711 : /**
712 : * @brief Convert a raw ECDSA signature to ASN.1 signature (per X9.62) as used by TLS libraries.
713 : *
714 : * Errors are:
715 : * - CHIP_ERROR_INVALID_ARGUMENT on any argument being invalid (e.g. nullptr), wrong sizes,
716 : * wrong or unsupported format,
717 : * - CHIP_ERROR_BUFFER_TOO_SMALL on running out of space at runtime.
718 : * - CHIP_ERROR_INTERNAL on any unexpected processing error.
719 : *
720 : * @param[in] fe_length_bytes Field Element length in bytes (e.g. 32 for P256 curve)
721 : * @param[in] raw_sig Raw signature of <r,s> concatenated
722 : * @param[out] out_asn1_sig ASN.1 DER signature format output buffer. Size must have space for at least
723 : * kMax_ECDSA_X9Dot62_Asn1_Overhead. On CHIP_NO_ERROR, the out_asn1_sig buffer will be re-assigned
724 : * to have the correct size based on variable-length output.
725 : * @return Returns a CHIP_ERROR on error, CHIP_NO_ERROR otherwise
726 : */
727 : CHIP_ERROR EcdsaRawSignatureToAsn1(size_t fe_length_bytes, const ByteSpan & raw_sig, MutableByteSpan & out_asn1_sig);
728 :
729 : /**
730 : * @brief Convert an ASN.1 DER signature (per X9.62) as used by TLS libraries to SEC1 raw format
731 : *
732 : * Errors are:
733 : * - CHIP_ERROR_INVALID_ARGUMENT on any argument being invalid (e.g. nullptr), wrong sizes,
734 : * wrong or unsupported format,
735 : * - CHIP_ERROR_BUFFER_TOO_SMALL on running out of space at runtime.
736 : * - CHIP_ERROR_INTERNAL on any unexpected processing error.
737 : *
738 : * @param[in] fe_length_bytes Field Element length in bytes (e.g. 32 for P256 curve)
739 : * @param[in] asn1_sig ASN.1 DER signature input
740 : * @param[out] out_raw_sig Raw signature of <r,s> concatenated format output buffer. Size must be at
741 : * least >= `2 * fe_length_bytes`. On CHIP_NO_ERROR, the out_raw_sig buffer will be re-assigned
742 : * to have the correct size (2 * fe_length_bytes).
743 : * @return Returns a CHIP_ERROR on error, CHIP_NO_ERROR otherwise
744 : */
745 : CHIP_ERROR EcdsaAsn1SignatureToRaw(size_t fe_length_bytes, const ByteSpan & asn1_sig, MutableByteSpan & out_raw_sig);
746 :
747 : /**
748 : * @brief Utility to read a length field after a tag in a DER-encoded stream.
749 : * @param[in] reader Reader instance from which the input will be read
750 : * @param[out] length Length of the following element read from the stream
751 : * @return CHIP_ERROR_INVALID_ARGUMENT or CHIP_ERROR_BUFFER_TOO_SMALL on error, CHIP_NO_ERROR otherwise
752 : */
753 : CHIP_ERROR ReadDerLength(chip::Encoding::LittleEndian::Reader & reader, size_t & length);
754 :
755 : /**
756 : * @brief Utility to emit a DER-encoded INTEGER given a raw unsigned large integer
757 : * in big-endian order. The `out_der_integer` span is updated to reflect the final
758 : * variable length, including tag and length, and must have at least `kEmitDerIntegerOverhead`
759 : * extra space in addition to the `raw_integer.size()`.
760 : * @param[in] raw_integer Bytes of a large unsigned integer in big-endian, possibly including leading zeroes
761 : * @param[out] out_der_integer Buffer to receive the DER-encoded integer
762 : * @return Returns CHIP_ERROR_INVALID_ARGUMENT or CHIP_ERROR_BUFFER_TOO_SMALL on error, CHIP_NO_ERROR otherwise.
763 : */
764 : CHIP_ERROR ConvertIntegerRawToDer(const ByteSpan & raw_integer, MutableByteSpan & out_der_integer);
765 :
766 : /**
767 : * @brief Utility to emit a DER-encoded INTEGER given a raw unsigned large integer
768 : * in big-endian order. The `out_der_integer` span is updated to reflect the final
769 : * variable length, excluding tag and length, and must have at least `kEmitDerIntegerWithoutTagOverhead`
770 : * extra space in addition to the `raw_integer.size()`.
771 : * @param[in] raw_integer Bytes of a large unsigned integer in big-endian, possibly including leading zeroes
772 : * @param[out] out_der_integer Buffer to receive the DER-encoded integer
773 : * @return Returns CHIP_ERROR_INVALID_ARGUMENT or CHIP_ERROR_BUFFER_TOO_SMALL on error, CHIP_NO_ERROR otherwise.
774 : */
775 : CHIP_ERROR ConvertIntegerRawToDerWithoutTag(const ByteSpan & raw_integer, MutableByteSpan & out_der_integer);
776 :
777 : /**
778 : * @brief A function that implements AES-CCM encryption
779 : *
780 : * This implements the CHIP_Crypto_AEAD_GenerateEncrypt() cryptographic primitive
781 : * from the specification. For an empty plaintext, the user of the API can provide
782 : * an empty string, or a nullptr, and provide plaintext_length as 0. The output buffer,
783 : * ciphertext can also be an empty string, or a nullptr for this case.
784 : *
785 : * @param plaintext Plaintext to encrypt
786 : * @param plaintext_length Length of plain_text
787 : * @param aad Additional authentication data
788 : * @param aad_length Length of additional authentication data
789 : * @param key Encryption key
790 : * @param nonce Encryption nonce
791 : * @param nonce_length Length of encryption nonce
792 : * @param ciphertext Buffer to write ciphertext into. Caller must ensure this is large enough to hold the ciphertext
793 : * @param tag Buffer to write tag into. Caller must ensure this is large enough to hold the tag
794 : * @param tag_length Expected length of tag
795 : * @return Returns a CHIP_ERROR on error, CHIP_NO_ERROR otherwise
796 : * */
797 : CHIP_ERROR AES_CCM_encrypt(const uint8_t * plaintext, size_t plaintext_length, const uint8_t * aad, size_t aad_length,
798 : const Aes128KeyHandle & key, const uint8_t * nonce, size_t nonce_length, uint8_t * ciphertext,
799 : uint8_t * tag, size_t tag_length);
800 :
801 : /**
802 : * @brief A function that implements AES-CCM decryption
803 : *
804 : * This implements the CHIP_Crypto_AEAD_DecryptVerify() cryptographic primitive
805 : * from the specification. For an empty ciphertext, the user of the API can provide
806 : * an empty string, or a nullptr, and provide ciphertext_length as 0. The output buffer,
807 : * plaintext can also be an empty string, or a nullptr for this case.
808 : *
809 : * @param ciphertext Ciphertext to decrypt
810 : * @param ciphertext_length Length of ciphertext
811 : * @param aad Additional authentical data.
812 : * @param aad_length Length of additional authentication data
813 : * @param tag Tag to use to decrypt
814 : * @param tag_length Length of tag
815 : * @param key Decryption key
816 : * @param nonce Encryption nonce
817 : * @param nonce_length Length of encryption nonce
818 : * @param plaintext Buffer to write plaintext into
819 : * @return Returns a CHIP_ERROR on error, CHIP_NO_ERROR otherwise
820 : **/
821 : CHIP_ERROR AES_CCM_decrypt(const uint8_t * ciphertext, size_t ciphertext_length, const uint8_t * aad, size_t aad_length,
822 : const uint8_t * tag, size_t tag_length, const Aes128KeyHandle & key, const uint8_t * nonce,
823 : size_t nonce_length, uint8_t * plaintext);
824 :
825 : /**
826 : * @brief A function that implements AES-CTR encryption/decryption
827 : *
828 : * This implements the AES-CTR-Encrypt/Decrypt() cryptographic primitives per sections
829 : * 3.7.1 and 3.7.2 of the specification. For an empty input, the user of the API
830 : * can provide an empty string, or a nullptr, and provide input as 0.
831 : * The output buffer can also be an empty string, or a nullptr for this case.
832 : *
833 : * @param input Input text to encrypt/decrypt
834 : * @param input_length Length of ciphertext
835 : * @param key Decryption key
836 : * @param nonce Encryption nonce
837 : * @param nonce_length Length of encryption nonce
838 : * @param output Buffer to write output into
839 : * @return Returns a CHIP_ERROR on error, CHIP_NO_ERROR otherwise
840 : **/
841 : CHIP_ERROR AES_CTR_crypt(const uint8_t * input, size_t input_length, const Aes128KeyHandle & key, const uint8_t * nonce,
842 : size_t nonce_length, uint8_t * output);
843 :
844 : /**
845 : * @brief Generate a PKCS#10 CSR, usable for Matter, from a P256Keypair.
846 : *
847 : * This uses first principles ASN.1 encoding to avoid relying on the CHIPCryptoPAL backend
848 : * itself, other than to provide an implementation of a P256Keypair * that supports
849 : * at least `::Pubkey()` and `::ECDSA_sign_msg`. This allows using it with
850 : * OS/Platform-bridged private key handling, without requiring a specific
851 : * implementation of other bits like ASN.1.
852 : *
853 : * The CSR will have subject OU set to `CSA`. This is needed since omiting
854 : * subject altogether often trips CSR parsing code. The profile at the CA can
855 : * be configured to ignore CSR requested subject.
856 : *
857 : * @param keypair The key pair for which a CSR should be generated. Must not be null.
858 : * @param csr_span Span to hold the resulting CSR. Must have size at least kMIN_CSR_Buffer_Size.
859 : * Otherwise returns CHIP_ERROR_BUFFER_TOO_SMALL. It will get resized to
860 : * actual size needed on success.
861 :
862 : * @return Returns a CHIP_ERROR from P256Keypair or ASN.1 backend on error, CHIP_NO_ERROR otherwise
863 : **/
864 : CHIP_ERROR GenerateCertificateSigningRequest(const P256Keypair * keypair, MutableByteSpan & csr_span);
865 :
866 : /**
867 : * @brief Common code to validate ASN.1 format/size of a CSR, used by VerifyCertificateSigningRequest.
868 : *
869 : * Ensures it's not obviously malformed and doesn't have trailing garbage.
870 : *
871 : * @param csr CSR in DER format
872 : * @param csr_length The length of the CSR buffer
873 : * @return CHIP_ERROR_UNSUPPORTED_CERT_FORMAT on invalid format, CHIP_NO_ERROR otherwise.
874 : */
875 : CHIP_ERROR VerifyCertificateSigningRequestFormat(const uint8_t * csr, size_t csr_length);
876 :
877 : /**
878 : * @brief Verify the Certificate Signing Request (CSR). If successfully verified, it outputs the public key from the CSR.
879 : *
880 : * The CSR is valid if the format is correct, the signature validates with the embedded public
881 : * key, and there is no trailing garbage data.
882 : *
883 : * @param csr CSR in DER format
884 : * @param csr_length The length of the CSR
885 : * @param pubkey The public key from the verified CSR
886 : * @return Returns a CHIP_ERROR on error, CHIP_NO_ERROR otherwise
887 : **/
888 : CHIP_ERROR VerifyCertificateSigningRequest(const uint8_t * csr, size_t csr_length, P256PublicKey & pubkey);
889 :
890 : /**
891 : * @brief A function that implements SHA-256 hash
892 : *
893 : * This implements the CHIP_Crypto_Hash() cryptographic primitive
894 : * in the the specification.
895 : *
896 : * @param data The data to hash
897 : * @param data_length Length of the data
898 : * @param out_buffer Pointer to buffer to write output into
899 : * @return Returns a CHIP_ERROR on error, CHIP_NO_ERROR otherwise
900 : **/
901 :
902 : CHIP_ERROR Hash_SHA256(const uint8_t * data, size_t data_length, uint8_t * out_buffer);
903 :
904 : /**
905 : * @brief A function that implements SHA-1 hash
906 : * @param data The data to hash
907 : * @param data_length Length of the data
908 : * @param out_buffer Pointer to buffer to write output into
909 : * @return Returns a CHIP_ERROR on error, CHIP_NO_ERROR otherwise
910 : **/
911 :
912 : CHIP_ERROR Hash_SHA1(const uint8_t * data, size_t data_length, uint8_t * out_buffer);
913 :
914 : /**
915 : * @brief A class that defines stream based implementation of SHA-256 hash
916 : * It's expected that the object of this class can be safely copied.
917 : * All implementations must check for std::is_trivially_copyable.
918 : **/
919 :
920 : struct alignas(CHIP_CONFIG_SHA256_CONTEXT_ALIGN) HashSHA256OpaqueContext
921 : {
922 : uint8_t mOpaque[kMAX_Hash_SHA256_Context_Size];
923 : };
924 :
925 : class Hash_SHA256_stream
926 : {
927 : public:
928 : Hash_SHA256_stream();
929 : ~Hash_SHA256_stream();
930 :
931 : /**
932 : * @brief Re-initialize digest computation to an empty context.
933 : *
934 : * @return CHIP_ERROR_INTERNAL on failure to initialize the context,
935 : * CHIP_NO_ERROR otherwise.
936 : */
937 : CHIP_ERROR Begin();
938 :
939 : /**
940 : * @brief Add some data to the digest computation, updating internal state.
941 : *
942 : * @param[in] data The span of bytes to include in the digest update process.
943 : *
944 : * @return CHIP_ERROR_INTERNAL on failure to ingest the data, CHIP_NO_ERROR otherwise.
945 : */
946 : CHIP_ERROR AddData(const ByteSpan data);
947 :
948 : /**
949 : * @brief Get the intermediate padded digest for the current state of the stream.
950 : *
951 : * More data can be added before finish is called.
952 : *
953 : * @param[in,out] out_buffer Output buffer to receive the digest. `out_buffer` must
954 : * be at least `kSHA256_Hash_Length` bytes long. The `out_buffer` size
955 : * will be set to `kSHA256_Hash_Length` on success.
956 : *
957 : * @return CHIP_ERROR_INTERNAL on failure to compute the digest, CHIP_ERROR_BUFFER_TOO_SMALL
958 : * if out_buffer is too small, CHIP_NO_ERROR otherwise.
959 : */
960 : CHIP_ERROR GetDigest(MutableByteSpan & out_buffer);
961 :
962 : /**
963 : * @brief Finalize the stream digest computation, getting the final digest.
964 : *
965 : * @param[in,out] out_buffer Output buffer to receive the digest. `out_buffer` must
966 : * be at least `kSHA256_Hash_Length` bytes long. The `out_buffer` size
967 : * will be set to `kSHA256_Hash_Length` on success.
968 : *
969 : * @return CHIP_ERROR_INTERNAL on failure to compute the digest, CHIP_ERROR_BUFFER_TOO_SMALL
970 : * if out_buffer is too small, CHIP_NO_ERROR otherwise.
971 : */
972 : CHIP_ERROR Finish(MutableByteSpan & out_buffer);
973 :
974 : /**
975 : * @brief Clear-out internal digest data to avoid lingering the state.
976 : */
977 : void Clear();
978 :
979 : private:
980 : // Check if the digest computation has been initialized; implement this if your backend needs it.
981 : bool IsInitialized();
982 :
983 : HashSHA256OpaqueContext mContext;
984 : };
985 :
986 : class HKDF_sha
987 : {
988 : public:
989 : HKDF_sha() = default;
990 3805 : virtual ~HKDF_sha() = default;
991 :
992 : /**
993 : * @brief A function that implements SHA-256 based HKDF
994 : *
995 : * This implements the CHIP_Crypto_KDF() cryptographic primitive
996 : * in the the specification.
997 : *
998 : * Error values are:
999 : * - CHIP_ERROR_INVALID_ARGUMENT: for any bad arguments or nullptr input on
1000 : * any pointer.
1001 : * - CHIP_ERROR_INTERNAL: for any unexpected error arising in the underlying
1002 : * cryptographic layers.
1003 : *
1004 : * @param secret The secret to use as the key to the HKDF
1005 : * @param secret_length Length of the secret
1006 : * @param salt Optional salt to use as input to the HKDF
1007 : * @param salt_length Length of the salt
1008 : * @param info Optional info to use as input to the HKDF
1009 : * @param info_length Length of the info
1010 : * @param out_buffer Pointer to buffer to write output into.
1011 : * @param out_length Size of the underlying out_buffer. That length of output key material will be generated in out_buffer.
1012 : * @return Returns a CHIP_ERROR on error, CHIP_NO_ERROR otherwise
1013 : **/
1014 :
1015 : virtual CHIP_ERROR HKDF_SHA256(const uint8_t * secret, size_t secret_length, const uint8_t * salt, size_t salt_length,
1016 : const uint8_t * info, size_t info_length, uint8_t * out_buffer, size_t out_length);
1017 : };
1018 :
1019 : class HMAC_sha
1020 : {
1021 : public:
1022 : HMAC_sha() = default;
1023 92 : virtual ~HMAC_sha() = default;
1024 :
1025 : /**
1026 : * @brief A function that implements SHA-256 based HMAC per FIPS1981.
1027 : *
1028 : * This implements the CHIP_Crypto_HMAC() cryptographic primitive
1029 : * in the the specification.
1030 : *
1031 : * The `out_length` must be at least kSHA256_Hash_Length, and only
1032 : * kSHA256_Hash_Length bytes are written to out_buffer.
1033 : *
1034 : * Error values are:
1035 : * - CHIP_ERROR_INVALID_ARGUMENT: for any bad arguments or nullptr input on
1036 : * any pointer.
1037 : * - CHIP_ERROR_INTERNAL: for any unexpected error arising in the underlying
1038 : * cryptographic layers.
1039 : *
1040 : * @param key The key to use for the HMAC operation
1041 : * @param key_length Length of the key
1042 : * @param message Message over which to compute the HMAC
1043 : * @param message_length Length of the message over which to compute the HMAC
1044 : * @param out_buffer Pointer to buffer into which to write the output.
1045 : * @param out_length Underlying size of the `out_buffer`.
1046 : * @return Returns a CHIP_ERROR on error, CHIP_NO_ERROR otherwise
1047 : **/
1048 :
1049 : virtual CHIP_ERROR HMAC_SHA256(const uint8_t * key, size_t key_length, const uint8_t * message, size_t message_length,
1050 : uint8_t * out_buffer, size_t out_length);
1051 :
1052 : /**
1053 : * @brief A function that implements SHA-256 based HMAC per FIPS1981.
1054 : *
1055 : * This implements the CHIP_Crypto_HMAC() cryptographic primitive
1056 : * in the the specification.
1057 : *
1058 : * The `out_length` must be at least kSHA256_Hash_Length, and only
1059 : * kSHA256_Hash_Length bytes are written to out_buffer.
1060 : *
1061 : * Error values are:
1062 : * - CHIP_ERROR_INVALID_ARGUMENT: for any bad arguments or nullptr input on
1063 : * any pointer.
1064 : * - CHIP_ERROR_INTERNAL: for any unexpected error arising in the underlying
1065 : * cryptographic layers.
1066 : *
1067 : * @param key The HMAC Key handle to use for the HMAC operation
1068 : * @param message Message over which to compute the HMAC
1069 : * @param message_length Length of the message over which to compute the HMAC
1070 : * @param out_buffer Pointer to buffer into which to write the output.
1071 : * @param out_length Underlying size of the `out_buffer`.
1072 : * @return Returns a CHIP_ERROR on error, CHIP_NO_ERROR otherwise
1073 : **/
1074 : virtual CHIP_ERROR HMAC_SHA256(const Hmac128KeyHandle & key, const uint8_t * message, size_t message_length,
1075 : uint8_t * out_buffer, size_t out_length);
1076 : };
1077 :
1078 : /**
1079 : * @brief A cryptographically secure random number generator based on NIST SP800-90A
1080 : * @param out_buffer Buffer into which to write random bytes
1081 : * @param out_length Number of random bytes to generate
1082 : * @return Returns a CHIP_ERROR on error, CHIP_NO_ERROR otherwise
1083 : **/
1084 : CHIP_ERROR DRBG_get_bytes(uint8_t * out_buffer, size_t out_length);
1085 :
1086 : /** @brief Entropy callback function
1087 : * @param data Callback-specific data pointer
1088 : * @param output Output data to fill
1089 : * @param len Length of output buffer
1090 : * @param olen The actual amount of data that was written to output buffer
1091 : * @return 0 if success
1092 : */
1093 : typedef int (*entropy_source)(void * data, uint8_t * output, size_t len, size_t * olen);
1094 :
1095 : /** @brief A function to add entropy sources to crypto library
1096 : *
1097 : * This function can be called multiple times to add multiple entropy sources. However,
1098 : * once the entropy source is added, it cannot be removed. Please make sure that the
1099 : * entropy source is valid for the lifetime of the application. Also, make sure that the
1100 : * same entropy source is not added multiple times, e.g.: by calling this function
1101 : * in class constructor or initialization function.
1102 : *
1103 : * @param fn_source Function pointer to the entropy source
1104 : * @param p_source Data that should be provided when fn_source is called
1105 : * @param threshold Minimum required from source before entropy is released
1106 : * @return Returns a CHIP_ERROR on error, CHIP_NO_ERROR otherwise
1107 : **/
1108 : CHIP_ERROR add_entropy_source(entropy_source fn_source, void * p_source, size_t threshold);
1109 :
1110 : class PBKDF2_sha256
1111 : {
1112 : public:
1113 : PBKDF2_sha256() = default;
1114 9 : virtual ~PBKDF2_sha256() = default;
1115 :
1116 : /** @brief Function to derive key using password. SHA256 hashing algorithm is used for calculating hmac.
1117 : * @param password password used for key derivation
1118 : * @param plen length of buffer containing password
1119 : * @param salt salt to use as input to the KDF
1120 : * @param slen length of salt
1121 : * @param iteration_count number of iterations to run
1122 : * @param key_length length of output key
1123 : * @param output output buffer where the key will be written
1124 : * @return Returns a CHIP_ERROR on error, CHIP_NO_ERROR otherwise
1125 : **/
1126 : virtual CHIP_ERROR pbkdf2_sha256(const uint8_t * password, size_t plen, const uint8_t * salt, size_t slen,
1127 : unsigned int iteration_count, uint32_t key_length, uint8_t * output);
1128 : };
1129 :
1130 : // TODO: Extract Spake2p to a separate header and replace the forward declaration with #include SessionKeystore.h
1131 : class SessionKeystore;
1132 :
1133 : /**
1134 : * The below class implements the draft 01 version of the Spake2+ protocol as
1135 : * defined in https://www.ietf.org/id/draft-bar-cfrg-spake2plus-01.html.
1136 : *
1137 : * The following describes the protocol flows:
1138 : *
1139 : * Commissioner Accessory
1140 : * ------------ ---------
1141 : *
1142 : * Init
1143 : * BeginProver
1144 : * ComputeRoundOne ------------->
1145 : * Init
1146 : * BeginVerifier
1147 : * /- ComputeRoundOne
1148 : * <------------- ComputeRoundTwo
1149 : * ComputeRoundTwo ------------->
1150 : * KeyConfirm KeyConfirm
1151 : * GetKeys GetKeys
1152 : *
1153 : **/
1154 : class Spake2p
1155 : {
1156 : public:
1157 : Spake2p(size_t fe_size, size_t point_size, size_t hash_size);
1158 20 : virtual ~Spake2p() = default;
1159 :
1160 : /**
1161 : * @brief Initialize Spake2+ with some context specific information.
1162 : *
1163 : * @param context The context is arbitrary but should include information about the
1164 : * protocol being run, contain the transcript for negotiation, include
1165 : * the PKBDF parameters, etc.
1166 : * @param context_len The length of the context.
1167 : *
1168 : * @return Returns a CHIP_ERROR on error, CHIP_NO_ERROR otherwise
1169 : **/
1170 : virtual CHIP_ERROR Init(const uint8_t * context, size_t context_len);
1171 :
1172 : /**
1173 : * @brief Free Spake2+ underlying objects.
1174 : **/
1175 : virtual void Clear() = 0;
1176 :
1177 : /**
1178 : * @brief Start the Spake2+ process as a verifier (i.e. an accessory being provisioned).
1179 : *
1180 : * @param my_identity The verifier identity. May be NULL if identities are not established.
1181 : * @param my_identity_len The verifier identity length.
1182 : * @param peer_identity The peer identity. May be NULL if identities are not established.
1183 : * @param peer_identity_len The peer identity length.
1184 : * @param w0in The input w0 (a parameter baked into the device or computed with ComputeW0).
1185 : * @param w0in_len The input w0 length.
1186 : * @param Lin The input L (a parameter baked into the device or computed with ComputeL).
1187 : * @param Lin_len The input L length.
1188 : *
1189 : * @return Returns a CHIP_ERROR on error, CHIP_NO_ERROR otherwise
1190 : **/
1191 : virtual CHIP_ERROR BeginVerifier(const uint8_t * my_identity, size_t my_identity_len, const uint8_t * peer_identity,
1192 : size_t peer_identity_len, const uint8_t * w0in, size_t w0in_len, const uint8_t * Lin,
1193 : size_t Lin_len);
1194 :
1195 : /**
1196 : * @brief Start the Spake2+ process as a prover (i.e. a commissioner).
1197 : *
1198 : * @param my_identity The prover identity. May be NULL if identities are not established.
1199 : * @param my_identity_len The prover identity length.
1200 : * @param peer_identity The peer identity. May be NULL if identities are not established.
1201 : * @param peer_identity_len The peer identity length.
1202 : * @param w0sin The input w0s (an output from the PBKDF).
1203 : * @param w0sin_len The input w0s length.
1204 : * @param w1sin The input w1s (an output from the PBKDF).
1205 : * @param w1sin_len The input w1s length.
1206 : *
1207 : * @return Returns a CHIP_ERROR on error, CHIP_NO_ERROR otherwise
1208 : **/
1209 : virtual CHIP_ERROR BeginProver(const uint8_t * my_identity, size_t my_identity_len, const uint8_t * peer_identity,
1210 : size_t peer_identity_len, const uint8_t * w0sin, size_t w0sin_len, const uint8_t * w1sin,
1211 : size_t w1sin_len);
1212 :
1213 : /**
1214 : * @brief Compute the first round of the protocol.
1215 : *
1216 : * @param pab X value from commissioner.
1217 : * @param pab_len X length.
1218 : * @param out The output first round Spake2+ contribution.
1219 : * @param out_len The output first round Spake2+ contribution length.
1220 : *
1221 : * @return Returns a CHIP_ERROR on error, CHIP_NO_ERROR otherwise
1222 : **/
1223 : virtual CHIP_ERROR ComputeRoundOne(const uint8_t * pab, size_t pab_len, uint8_t * out, size_t * out_len);
1224 :
1225 : /**
1226 : * @brief Compute the second round of the protocol.
1227 : *
1228 : * @param in The peer first round Spake2+ contribution.
1229 : * @param in_len The peer first round Spake2+ contribution length.
1230 : * @param out The output second round Spake2+ contribution.
1231 : * @param out_len The output second round Spake2+ contribution length.
1232 : *
1233 : * @return Returns a CHIP_ERROR on error, CHIP_NO_ERROR otherwise
1234 : **/
1235 : virtual CHIP_ERROR ComputeRoundTwo(const uint8_t * in, size_t in_len, uint8_t * out, size_t * out_len);
1236 :
1237 : /**
1238 : * @brief Confirm that each party computed the same keys.
1239 : *
1240 : * @param in The peer second round Spake2+ contribution.
1241 : * @param in_len The peer second round Spake2+ contribution length.
1242 : *
1243 : * @return Returns a CHIP_ERROR on error, CHIP_NO_ERROR otherwise
1244 : **/
1245 : virtual CHIP_ERROR KeyConfirm(const uint8_t * in, size_t in_len);
1246 :
1247 : /**
1248 : * @brief Return the shared HKDF key.
1249 : *
1250 : * Returns the shared key established during the Spake2+ process, which can be used
1251 : * to derive application-specific keys using HKDF.
1252 : *
1253 : * @param keystore The session keystore for managing the HKDF key lifetime.
1254 : * @param key The output HKDF key.
1255 : *
1256 : * @return Returns a CHIP_ERROR on error, CHIP_NO_ERROR otherwise
1257 : **/
1258 : CHIP_ERROR GetKeys(SessionKeystore & keystore, HkdfKeyHandle & key);
1259 :
1260 : CHIP_ERROR InternalHash(const uint8_t * in, size_t in_len);
1261 : CHIP_ERROR WriteMN();
1262 : CHIP_ERROR GenerateKeys();
1263 :
1264 : /**
1265 : * @brief Load a field element.
1266 : *
1267 : * @param in The input big endian field element.
1268 : * @param in_len The size of the input buffer in bytes.
1269 : * @param fe A pointer to an initialized implementation dependant field element.
1270 : *
1271 : * @return Returns a CHIP_ERROR on error, CHIP_NO_ERROR otherwise
1272 : **/
1273 : virtual CHIP_ERROR FELoad(const uint8_t * in, size_t in_len, void * fe) = 0;
1274 :
1275 : /**
1276 : * @brief Write a field element in big-endian format.
1277 : *
1278 : * @param fe The field element to write.
1279 : * @param out The output buffer.
1280 : * @param out_len The length of the output buffer.
1281 : *
1282 : * @return Returns a CHIP_ERROR on error, CHIP_NO_ERROR otherwise
1283 : **/
1284 : virtual CHIP_ERROR FEWrite(const void * fe, uint8_t * out, size_t out_len) = 0;
1285 :
1286 : /**
1287 : * @brief Generate a field element.
1288 : *
1289 : * @param fe A pointer to an initialized implementation dependant field element.
1290 : *
1291 : * @note The implementation must generate a random element from [0, q) where q is the curve order.
1292 : *
1293 : * @return Returns a CHIP_ERROR on error, CHIP_NO_ERROR otherwise
1294 : **/
1295 : virtual CHIP_ERROR FEGenerate(void * fe) = 0;
1296 :
1297 : /**
1298 : * @brief Multiply two field elements, fer = fe1 * fe2.
1299 : *
1300 : * @param fer A pointer to an initialized implementation dependant field element.
1301 : * @param fe1 A pointer to an initialized implementation dependant field element.
1302 : * @param fe2 A pointer to an initialized implementation dependant field element.
1303 : *
1304 : * @note The result must be a field element (i.e. reduced by the curve order).
1305 : *
1306 : * @return Returns a CHIP_ERROR on error, CHIP_NO_ERROR otherwise
1307 : **/
1308 : virtual CHIP_ERROR FEMul(void * fer, const void * fe1, const void * fe2) = 0;
1309 :
1310 : /**
1311 : * @brief Load a point from 0x04 || X || Y format
1312 : *
1313 : * @param in Input buffer
1314 : * @param in_len Input buffer length
1315 : * @param R A pointer to an initialized implementation dependant point.
1316 : *
1317 : * @return Returns a CHIP_ERROR on error, CHIP_NO_ERROR otherwise
1318 : **/
1319 : virtual CHIP_ERROR PointLoad(const uint8_t * in, size_t in_len, void * R) = 0;
1320 :
1321 : /**
1322 : * @brief Write a point in 0x04 || X || Y format
1323 : *
1324 : * @param R A pointer to an initialized implementation dependant point.
1325 : * @param out Output buffer
1326 : * @param out_len Length of the output buffer
1327 : *
1328 : * @return Returns a CHIP_ERROR on error, CHIP_NO_ERROR otherwise
1329 : **/
1330 : virtual CHIP_ERROR PointWrite(const void * R, uint8_t * out, size_t out_len) = 0;
1331 :
1332 : /**
1333 : * @brief Scalar multiplication, R = fe1 * P1.
1334 : *
1335 : * @param R Resultant point
1336 : * @param P1 Input point
1337 : * @param fe1 Input field element.
1338 : *
1339 : * @return Returns a CHIP_ERROR on error, CHIP_NO_ERROR otherwise
1340 : **/
1341 : virtual CHIP_ERROR PointMul(void * R, const void * P1, const void * fe1) = 0;
1342 :
1343 : /**
1344 : * @brief Scalar multiplication with addition, R = fe1 * P1 + fe2 * P2.
1345 : *
1346 : * @param R Resultant point
1347 : * @param P1 Input point
1348 : * @param fe1 Input field element.
1349 : * @param P2 Input point
1350 : * @param fe2 Input field element.
1351 : *
1352 : * @return Returns a CHIP_ERROR on error, CHIP_NO_ERROR otherwise
1353 : **/
1354 : virtual CHIP_ERROR PointAddMul(void * R, const void * P1, const void * fe1, const void * P2, const void * fe2) = 0;
1355 :
1356 : /**
1357 : * @brief Point inversion.
1358 : *
1359 : * @param R Input/Output point to point_invert
1360 : *
1361 : * @return Returns a CHIP_ERROR on error, CHIP_NO_ERROR otherwise
1362 : **/
1363 : virtual CHIP_ERROR PointInvert(void * R) = 0;
1364 :
1365 : /**
1366 : * @brief Multiply a point by the curve cofactor.
1367 : *
1368 : * @param R Input/Output point to point_invert
1369 : *
1370 : * @return Returns a CHIP_ERROR on error, CHIP_NO_ERROR otherwise
1371 : **/
1372 : virtual CHIP_ERROR PointCofactorMul(void * R) = 0;
1373 :
1374 : /*
1375 : * @synopsis Check if a point is on the curve.
1376 : *
1377 : * @param R Input point to check.
1378 : *
1379 : * @return CHIP_NO_ERROR if the point is valid, CHIP_ERROR otherwise.
1380 : */
1381 : virtual CHIP_ERROR PointIsValid(void * R) = 0;
1382 :
1383 : /*
1384 : * @synopsis Compute w0sin mod p
1385 : *
1386 : * @param w0out Output field element w0
1387 : * @param w0_len Output field element length
1388 : * @param w0sin Input field element
1389 : * @param w0sin_len Input field element length
1390 : *
1391 : * @return Returns a CHIP_ERROR on error, CHIP_NO_ERROR otherwise
1392 : **/
1393 : virtual CHIP_ERROR ComputeW0(uint8_t * w0out, size_t * w0_len, const uint8_t * w0sin, size_t w0sin_len) = 0;
1394 :
1395 : /*
1396 : * @synopsis Compute w1in*G where w1in is w1sin mod p
1397 : *
1398 : * @param Lout Output point in 0x04 || X || Y format.
1399 : * @param L_len Output point length
1400 : * @param w1sin Input field element
1401 : * @param w1sin_len Input field element size
1402 : *
1403 : * @return Returns a CHIP_ERROR on error, CHIP_NO_ERROR otherwise
1404 : **/
1405 : virtual CHIP_ERROR ComputeL(uint8_t * Lout, size_t * L_len, const uint8_t * w1sin, size_t w1sin_len) = 0;
1406 :
1407 : void * M;
1408 : void * N;
1409 : const void * G;
1410 : void * X;
1411 : void * Y;
1412 : void * L;
1413 : void * Z;
1414 : void * V;
1415 : void * w0;
1416 : void * w1;
1417 : void * xy;
1418 : void * order;
1419 : void * tempbn;
1420 :
1421 : protected:
1422 : /**
1423 : * @brief Initialize underlying implementation curve, points, field elements, etc.
1424 : *
1425 : * @details The implementation needs to:
1426 : * 1. Initialize each of the points below and set the relevant pointers on the class:
1427 : * a. M
1428 : * b. N
1429 : * c. G
1430 : * d. X
1431 : * e. Y
1432 : * f. L
1433 : * g. Z
1434 : * h. V
1435 : *
1436 : * As an example:
1437 : * this.M = implementation_alloc_point();
1438 : * 2. Initialize each of the field elements below and set the relevant pointers on the class:
1439 : * a. w0
1440 : * b. w1
1441 : * c. xy
1442 : * d. tempbn
1443 : * 3. The hashing context should be initialized
1444 : *
1445 : * @return Returns a CHIP_ERROR on error, CHIP_NO_ERROR otherwise
1446 : **/
1447 : virtual CHIP_ERROR InitImpl() = 0;
1448 :
1449 : /**
1450 : * @brief Hash in_len bytes of in into the internal hash context.
1451 : *
1452 : * @param in The input buffer.
1453 : * @param in_len Size of the input buffer in bytes.
1454 : *
1455 : * @return Returns a CHIP_ERROR on error, CHIP_NO_ERROR otherwise
1456 : **/
1457 : virtual CHIP_ERROR Hash(const uint8_t * in, size_t in_len) = 0;
1458 :
1459 : /**
1460 : * @brief Return the hash.
1461 : *
1462 : * @param out_span Output buffer. The size available must be >= the hash size. It gets resized
1463 : * to hash size on success.
1464 : *
1465 : * @return Returns a CHIP_ERROR on error, CHIP_NO_ERROR otherwise
1466 : **/
1467 : virtual CHIP_ERROR HashFinalize(MutableByteSpan & out_span) = 0;
1468 :
1469 : /**
1470 : * @brief Generate a message authentication code.
1471 : *
1472 : * @param key The MAC key buffer.
1473 : * @param key_len The size of the MAC key in bytes.
1474 : * @param in The input buffer.
1475 : * @param in_len The size of the input data to MAC in bytes.
1476 : * @param out_span The output MAC buffer span. Size must be >= the hash_size. Output size is updated to fit on success.
1477 : *
1478 : * @return Returns a CHIP_ERROR on error, CHIP_NO_ERROR otherwise
1479 : **/
1480 : virtual CHIP_ERROR Mac(const uint8_t * key, size_t key_len, const uint8_t * in, size_t in_len, MutableByteSpan & out_span) = 0;
1481 :
1482 : /**
1483 : * @brief Verify a message authentication code.
1484 : *
1485 : * @param key The MAC key buffer.
1486 : * @param key_len The size of the MAC key in bytes.
1487 : * @param mac The input MAC buffer.
1488 : * @param mac_len The size of the MAC in bytes.
1489 : * @param in The input buffer to verify.
1490 : * @param in_len The size of the input data to verify in bytes.
1491 : *
1492 : * @return Returns a CHIP_ERROR when the MAC doesn't validate, CHIP_NO_ERROR otherwise.
1493 : **/
1494 : virtual CHIP_ERROR MacVerify(const uint8_t * key, size_t key_len, const uint8_t * mac, size_t mac_len, const uint8_t * in,
1495 : size_t in_len) = 0;
1496 :
1497 : /**
1498 : * @brief Derive an key of length out_len.
1499 : *
1500 : * @param ikm The input key material buffer.
1501 : * @param ikm_len The input key material length.
1502 : * @param salt The optional salt. This may be NULL.
1503 : * @param salt_len The size of the salt in bytes.
1504 : * @param info The info.
1505 : * @param info_len The size of the info in bytes.
1506 : * @param out The output key
1507 : * @param out_len The output key length
1508 : *
1509 : * @return Returns a CHIP_ERROR when the MAC doesn't validate, CHIP_NO_ERROR otherwise.
1510 : **/
1511 : virtual CHIP_ERROR KDF(const uint8_t * ikm, size_t ikm_len, const uint8_t * salt, size_t salt_len, const uint8_t * info,
1512 : size_t info_len, uint8_t * out, size_t out_len) = 0;
1513 :
1514 : CHIP_SPAKE2P_ROLE role;
1515 : CHIP_SPAKE2P_STATE state = CHIP_SPAKE2P_STATE::PREINIT;
1516 : size_t fe_size;
1517 : size_t hash_size;
1518 : size_t point_size;
1519 : uint8_t Kcab[kMAX_Hash_Length];
1520 : uint8_t Kae[kMAX_Hash_Length];
1521 : uint8_t * Kca;
1522 : uint8_t * Kcb;
1523 : uint8_t * Ka;
1524 : uint8_t * Ke;
1525 : };
1526 :
1527 : struct alignas(size_t) Spake2pOpaqueContext
1528 : {
1529 : uint8_t mOpaque[kMAX_Spake2p_Context_Size];
1530 : };
1531 :
1532 : class Spake2p_P256_SHA256_HKDF_HMAC : public Spake2p
1533 : {
1534 : public:
1535 5 : Spake2p_P256_SHA256_HKDF_HMAC() : Spake2p(kP256_FE_Length, kP256_Point_Length, kSHA256_Hash_Length)
1536 : {
1537 5 : memset(&mSpake2pContext, 0, sizeof(mSpake2pContext));
1538 5 : }
1539 :
1540 20 : ~Spake2p_P256_SHA256_HKDF_HMAC() override { Spake2p_P256_SHA256_HKDF_HMAC::Clear(); }
1541 :
1542 : void Clear() override;
1543 : CHIP_ERROR Mac(const uint8_t * key, size_t key_len, const uint8_t * in, size_t in_len, MutableByteSpan & out_span) override;
1544 : CHIP_ERROR MacVerify(const uint8_t * key, size_t key_len, const uint8_t * mac, size_t mac_len, const uint8_t * in,
1545 : size_t in_len) override;
1546 : CHIP_ERROR FELoad(const uint8_t * in, size_t in_len, void * fe) override;
1547 : CHIP_ERROR FEWrite(const void * fe, uint8_t * out, size_t out_len) override;
1548 : CHIP_ERROR FEGenerate(void * fe) override;
1549 : CHIP_ERROR FEMul(void * fer, const void * fe1, const void * fe2) override;
1550 :
1551 : CHIP_ERROR PointLoad(const uint8_t * in, size_t in_len, void * R) override;
1552 : CHIP_ERROR PointWrite(const void * R, uint8_t * out, size_t out_len) override;
1553 : CHIP_ERROR PointMul(void * R, const void * P1, const void * fe1) override;
1554 : CHIP_ERROR PointAddMul(void * R, const void * P1, const void * fe1, const void * P2, const void * fe2) override;
1555 : CHIP_ERROR PointInvert(void * R) override;
1556 : CHIP_ERROR PointCofactorMul(void * R) override;
1557 : CHIP_ERROR PointIsValid(void * R) override;
1558 :
1559 : CHIP_ERROR ComputeW0(uint8_t * w0out, size_t * w0_len, const uint8_t * w0sin, size_t w0sin_len) override;
1560 : CHIP_ERROR ComputeL(uint8_t * Lout, size_t * L_len, const uint8_t * w1sin, size_t w1sin_len) override;
1561 :
1562 : protected:
1563 : CHIP_ERROR InitImpl() override;
1564 : CHIP_ERROR Hash(const uint8_t * in, size_t in_len) override;
1565 : CHIP_ERROR HashFinalize(MutableByteSpan & out_span) override;
1566 : CHIP_ERROR KDF(const uint8_t * secret, size_t secret_length, const uint8_t * salt, size_t salt_length, const uint8_t * info,
1567 : size_t info_length, uint8_t * out, size_t out_length) override;
1568 :
1569 : private:
1570 : CHIP_ERROR InitInternal();
1571 : Hash_SHA256_stream sha256_hash_ctx;
1572 :
1573 : Spake2pOpaqueContext mSpake2pContext;
1574 : };
1575 :
1576 : /**
1577 : * @brief Class used for verifying PASE secure sessions.
1578 : **/
1579 : class Spake2pVerifier
1580 : {
1581 : public:
1582 : uint8_t mW0[kP256_FE_Length];
1583 : uint8_t mL[kP256_Point_Length];
1584 :
1585 : CHIP_ERROR Serialize(MutableByteSpan & outSerialized) const;
1586 : CHIP_ERROR Deserialize(const ByteSpan & inSerialized);
1587 :
1588 : /**
1589 : * @brief Generate the Spake2+ verifier.
1590 : *
1591 : * @param pbkdf2IterCount Iteration count for PBKDF2 function
1592 : * @param salt Salt to be used for Spake2+ operation
1593 : * @param setupPin Provided setup PIN (passcode)
1594 : *
1595 : * @return CHIP_ERROR The result of Spake2+ verifier generation
1596 : */
1597 : CHIP_ERROR Generate(uint32_t pbkdf2IterCount, const ByteSpan & salt, uint32_t setupPin);
1598 :
1599 : /**
1600 : * @brief Compute the initiator values (w0s, w1s) used for PAKE input.
1601 : *
1602 : * @param pbkdf2IterCount Iteration count for PBKDF2 function
1603 : * @param salt Salt to be used for Spake2+ operation
1604 : * @param setupPin Provided setup PIN (passcode)
1605 : * @param ws The output pair (w0s, w1s) stored sequentially
1606 : * @param ws_len The output length
1607 : *
1608 : * @return CHIP_ERROR The result from running PBKDF2
1609 : */
1610 : static CHIP_ERROR ComputeWS(uint32_t pbkdf2IterCount, const ByteSpan & salt, uint32_t setupPin, uint8_t * ws, uint32_t ws_len);
1611 : };
1612 :
1613 : /**
1614 : * @brief Serialized format of the Spake2+ Verifier components.
1615 : *
1616 : * This is used when the Verifier should be presented in a serialized form.
1617 : * For example, when it is generated using PBKDF function, when stored in the
1618 : * memory or when sent over the wire.
1619 : * The serialized format is concatentation of 'W0' and 'L' verifier components:
1620 : * { Spake2pVerifier.mW0[kP256_FE_Length], Spake2pVerifier.mL[kP256_Point_Length] }
1621 : **/
1622 : typedef uint8_t Spake2pVerifierSerialized[kSpake2p_VerifierSerialized_Length];
1623 :
1624 : /**
1625 : * @brief Compute the compressed fabric identifier used for operational discovery service
1626 : * records from a Node's root public key and Fabric ID. On success, out_compressed_fabric_id
1627 : * will have a size of exactly kCompressedFabricIdentifierSize.
1628 : *
1629 : * Errors are:
1630 : * - CHIP_ERROR_INVALID_ARGUMENT if root_public_key is invalid
1631 : * - CHIP_ERROR_BUFFER_TOO_SMALL if out_compressed_fabric_id is too small for serialization
1632 : * - CHIP_ERROR_INTERNAL on any unexpected crypto or data conversion errors.
1633 : *
1634 : * @param[in] root_public_key The root public key associated with the node's fabric
1635 : * @param[in] fabric_id The fabric ID associated with the node's fabric
1636 : * @param[out] out_compressed_fabric_id Span where output will be written. Its size must be >= kCompressedFabricIdentifierSize.
1637 : * @returns a CHIP_ERROR (see above) on failure or CHIP_NO_ERROR otherwise.
1638 : */
1639 : CHIP_ERROR GenerateCompressedFabricId(const Crypto::P256PublicKey & root_public_key, uint64_t fabric_id,
1640 : MutableByteSpan & out_compressed_fabric_id);
1641 :
1642 : /**
1643 : * @brief Compute the compressed fabric identifier used for operational discovery service
1644 : * records from a Node's root public key and Fabric ID. This is a conveniance
1645 : * overload that writes to a uint64_t (CompressedFabricId) type.
1646 : *
1647 : * @param[in] rootPublicKey The root public key associated with the node's fabric
1648 : * @param[in] fabricId The fabric ID associated with the node's fabric
1649 : * @param[out] compressedFabricId output location for compressed fabric ID
1650 : * @returns a CHIP_ERROR on failure or CHIP_NO_ERROR otherwise.
1651 : */
1652 : CHIP_ERROR GenerateCompressedFabricId(const Crypto::P256PublicKey & rootPublicKey, uint64_t fabricId,
1653 : uint64_t & compressedFabricId);
1654 :
1655 : enum class CertificateChainValidationResult
1656 : {
1657 : kSuccess = 0,
1658 :
1659 : kRootFormatInvalid = 100,
1660 : kRootArgumentInvalid = 101,
1661 :
1662 : kICAFormatInvalid = 200,
1663 : kICAArgumentInvalid = 201,
1664 :
1665 : kLeafFormatInvalid = 300,
1666 : kLeafArgumentInvalid = 301,
1667 :
1668 : kChainInvalid = 400,
1669 :
1670 : kNoMemory = 500,
1671 :
1672 : kInternalFrameworkError = 600,
1673 : };
1674 :
1675 : CHIP_ERROR ValidateCertificateChain(const uint8_t * rootCertificate, size_t rootCertificateLen, const uint8_t * caCertificate,
1676 : size_t caCertificateLen, const uint8_t * leafCertificate, size_t leafCertificateLen,
1677 : CertificateChainValidationResult & result);
1678 :
1679 : enum class AttestationCertType
1680 : {
1681 : kPAA = 0,
1682 : kPAI = 1,
1683 : kDAC = 2,
1684 : };
1685 :
1686 : CHIP_ERROR VerifyAttestationCertificateFormat(const ByteSpan & cert, AttestationCertType certType);
1687 :
1688 : /**
1689 : * @brief Generate a VendorFabricBindingMessage as used by the Fabric Table Vendor ID Verification Procedure.
1690 : *
1691 : * @param[in] fabricBindingVersion - Version of binding payload to generate. outputSpan size requirements are based on this.
1692 : * @param[in] rootPublicKey - Root public key for the fabric in question
1693 : * @param[in] fabricId - Fabric ID for the fabric in question
1694 : * @param[in] vendorId - Vendor ID for the fabric in question
1695 : * @param[inout] outputSpan - Span that will receive the binding message. Must be large enough for the
1696 : * payload (otherwise CHIP_ERROR_BUFFER_TOO_SMALL) and will be resized to fit.
1697 : * @return CHIP_NO_ERROR on success, otherwise another CHIP_ERROR value representative of the failure.
1698 : */
1699 : CHIP_ERROR GenerateVendorFabricBindingMessage(FabricBindingVersion fabricBindingVersion, const P256PublicKey & rootPublicKey,
1700 : FabricId fabricId, uint16_t vendorId, MutableByteSpan & outputSpan);
1701 :
1702 : /**
1703 : * @brief Generate the message to be signed for the Fabric Table Vendor ID Verification Procedure.
1704 : *
1705 : * The Fabric Binding Version value will be recovered from the vendorFabricBindingMessage.
1706 : *
1707 : * @param fabricIndex - Fabric Index for the fabric in question
1708 : * @param clientChallenge - Client challenge to use
1709 : * @param attestationChallenge - Attestation challenge to use
1710 : * @param vendorFabricBindingMessage - The VendorFabricBindingMessage previously computed for the fabric
1711 : * @param vidVerificationStatement - The VID Verification Statement to include in signature (may be empty)
1712 : * @param outputSpan - Span that will receive the to-be-signed message. Must be large enough for the
1713 : * payload (otherwise CHIP_ERROR_BUFFER_TOO_SMALL) and will be resized to fit.
1714 : * @return CHIP_NO_ERROR on success, otherwise another CHIP_ERROR value representative of the failure.
1715 : */
1716 : CHIP_ERROR GenerateVendorIdVerificationToBeSigned(FabricIndex fabricIndex, const ByteSpan & clientChallenge,
1717 : const ByteSpan & attestationChallenge,
1718 : const ByteSpan & vendorFabricBindingMessage,
1719 : const ByteSpan & vidVerificationStatement, MutableByteSpan & outputSpan);
1720 :
1721 : /**
1722 : * @brief Validate notBefore timestamp of a certificate (candidateCertificate) against validity period of the
1723 : * issuer certificate (issuerCertificate).
1724 : *
1725 : * Errors are:
1726 : * - CHIP_ERROR_CERT_EXPIRED if the candidateCertificate timestamp does not satisfy the issuerCertificate's timestamp.
1727 : * - CHIP_ERROR_INVALID_ARGUMENT when passing an invalid argument.
1728 : * - CHIP_ERROR_INTERNAL on any unexpected crypto or data conversion errors.
1729 : *
1730 : * @param candidateCertificate A DER Certificate ByteSpan those notBefore timestamp to be evaluated.
1731 : * @param issuerCertificate A DER Certificate ByteSpan used to evaluate validity timestamp of the candidateCertificate.
1732 : *
1733 : * @returns a CHIP_ERROR (see above) on failure or CHIP_NO_ERROR otherwise.
1734 : **/
1735 : CHIP_ERROR IsCertificateValidAtIssuance(const ByteSpan & candidateCertificate, const ByteSpan & issuerCertificate);
1736 :
1737 : /**
1738 : * @brief Validate a certificate's validity date against current time.
1739 : *
1740 : * Errors are:
1741 : * - CHIP_ERROR_CERT_EXPIRED if the certificate has expired.
1742 : * - CHIP_ERROR_INVALID_ARGUMENT when passing an invalid argument.
1743 : * - CHIP_ERROR_INTERNAL on any unexpected crypto or data conversion errors.
1744 : *
1745 : * @param certificate A DER Certificate ByteSpan used as the validity reference to be checked against current time.
1746 : *
1747 : * @returns a CHIP_ERROR (see above) on failure or CHIP_NO_ERROR otherwise.
1748 : **/
1749 : CHIP_ERROR IsCertificateValidAtCurrentTime(const ByteSpan & certificate);
1750 :
1751 : CHIP_ERROR ExtractPubkeyFromX509Cert(const ByteSpan & certificate, Crypto::P256PublicKey & pubkey);
1752 :
1753 : /**
1754 : * @brief Extracts the Subject Key Identifier from an X509 Certificate.
1755 : **/
1756 : CHIP_ERROR ExtractSKIDFromX509Cert(const ByteSpan & certificate, MutableByteSpan & skid);
1757 :
1758 : /**
1759 : * @brief Extracts the Authority Key Identifier from an X509 Certificate.
1760 : **/
1761 : CHIP_ERROR ExtractAKIDFromX509Cert(const ByteSpan & certificate, MutableByteSpan & akid);
1762 :
1763 : /**
1764 : * @brief Extracts the CRL Distribution Point (CDP) extension from an X509 ASN.1 Encoded Certificate.
1765 : * The returned value only covers the URI of the CDP. Only a single URI distribution point
1766 : * GeneralName is supported, and only those that start with "http://" and "https://".
1767 : *
1768 : * @returns CHIP_ERROR_NOT_FOUND if not found or wrong format.
1769 : * CHIP_NO_ERROR otherwise.
1770 : **/
1771 : CHIP_ERROR ExtractCRLDistributionPointURIFromX509Cert(const ByteSpan & certificate, MutableCharSpan & cdpurl);
1772 :
1773 : /**
1774 : * @brief Extracts the CRL Distribution Point (CDP) extension's cRLIssuer Name from an X509 ASN.1 Encoded Certificate.
1775 : * The value is copied into buffer in a raw ASN.1 X.509 format. This format should be directly comparable
1776 : * with the result of ExtractSubjectFromX509Cert().
1777 : *
1778 : * @returns CHIP_ERROR_NOT_FOUND if not found or wrong format.
1779 : * CHIP_NO_ERROR otherwise.
1780 : **/
1781 : CHIP_ERROR ExtractCDPExtensionCRLIssuerFromX509Cert(const ByteSpan & certificate, MutableByteSpan & crlIssuer);
1782 :
1783 : /**
1784 : * @brief Extracts Serial Number from X509 Certificate.
1785 : **/
1786 : CHIP_ERROR ExtractSerialNumberFromX509Cert(const ByteSpan & certificate, MutableByteSpan & serialNumber);
1787 :
1788 : /**
1789 : * @brief Extracts Subject Distinguished Name from X509 Certificate. The value is copied into buffer in a raw ASN.1 X.509 format.
1790 : **/
1791 : CHIP_ERROR ExtractSubjectFromX509Cert(const ByteSpan & certificate, MutableByteSpan & subject);
1792 :
1793 : /**
1794 : * @brief Extracts Issuer Distinguished Name from X509 Certificate. The value is copied into buffer in a raw ASN.1 X.509 format.
1795 : **/
1796 : CHIP_ERROR ExtractIssuerFromX509Cert(const ByteSpan & certificate, MutableByteSpan & issuer);
1797 :
1798 : /**
1799 : * @brief Checks for resigned version of the certificate in the list and returns it.
1800 : *
1801 : * The following conditions SHOULD be satisfied for the certificate to qualify as
1802 : * a resigned version of a reference certificate:
1803 : * - SKID of the candidate and the reference certificate should match.
1804 : * - SubjectDN of the candidate and the reference certificate should match.
1805 : *
1806 : * If no resigned version is found then reference certificate itself is returned.
1807 : *
1808 : * @param referenceCertificate A DER certificate.
1809 : * @param candidateCertificates A pointer to the list of DER Certificates, which should be searched
1810 : * for the resigned version of `referenceCertificate`.
1811 : * @param candidateCertificatesCount Number of certificates in the `candidateCertificates` list.
1812 : * @param outCertificate A reference to the certificate or it's resigned version if found.
1813 : * Note that it points to either `referenceCertificate` or one of
1814 : * `candidateCertificates`, but it doesn't copy data.
1815 : *
1816 : * @returns error if there is certificate parsing/format issue or CHIP_NO_ERROR otherwise.
1817 : **/
1818 : CHIP_ERROR ReplaceCertIfResignedCertFound(const ByteSpan & referenceCertificate, const ByteSpan * candidateCertificates,
1819 : size_t candidateCertificatesCount, ByteSpan & outCertificate);
1820 :
1821 : /**
1822 : * Defines DN attribute types that can include endocing of VID/PID parameters.
1823 : */
1824 : enum class DNAttrType
1825 : {
1826 : kUnspecified = 0,
1827 : kCommonName = 1,
1828 : kMatterVID = 2,
1829 : kMatterPID = 3,
1830 : };
1831 :
1832 : /**
1833 : * @struct AttestationCertVidPid
1834 : *
1835 : * @brief
1836 : * A data structure representing Attestation Certificate VID and PID attributes.
1837 : */
1838 : struct AttestationCertVidPid
1839 : {
1840 : Optional<VendorId> mVendorId;
1841 : Optional<uint16_t> mProductId;
1842 :
1843 620 : bool Initialized() const { return (mVendorId.HasValue() || mProductId.HasValue()); }
1844 : };
1845 :
1846 : /**
1847 : * @brief Extracts VID and PID attributes from the DN Attribute string.
1848 : * If attribute is not present the corresponding output value stays uninitialized.
1849 : *
1850 : * @return CHIP_ERROR_INVALID_ARGUMENT if wrong input is provided.
1851 : * CHIP_ERROR_WRONG_CERT_DN if encoding of kMatterVID and kMatterPID attributes is wrong.
1852 : * CHIP_NO_ERROR otherwise.
1853 : **/
1854 : CHIP_ERROR ExtractVIDPIDFromAttributeString(DNAttrType attrType, const ByteSpan & attr,
1855 : AttestationCertVidPid & vidpidFromMatterAttr, AttestationCertVidPid & vidpidFromCNAttr);
1856 :
1857 : /**
1858 : * @brief Extracts VID and PID attributes from the Subject DN of an X509 Certificate.
1859 : * If attribute is not present the corresponding output value stays uninitialized.
1860 : **/
1861 : CHIP_ERROR ExtractVIDPIDFromX509Cert(const ByteSpan & x509Cert, AttestationCertVidPid & vidpid);
1862 :
1863 : /**
1864 : * @brief The set of credentials needed to operate group message security with symmetric keys.
1865 : */
1866 : typedef struct GroupOperationalCredentials
1867 : {
1868 : /// Validity start time in microseconds since 2000-01-01T00:00:00 UTC ("the Epoch")
1869 : uint64_t start_time;
1870 : /// Session Id
1871 : uint16_t hash;
1872 : /// Operational group key
1873 : uint8_t encryption_key[Crypto::CHIP_CRYPTO_SYMMETRIC_KEY_LENGTH_BYTES];
1874 : /// Privacy key
1875 : uint8_t privacy_key[Crypto::CHIP_CRYPTO_SYMMETRIC_KEY_LENGTH_BYTES];
1876 : } GroupOperationalCredentials;
1877 :
1878 : /**
1879 : * @brief Opaque context used to protect a symmetric key. The key operations must
1880 : * be performed without exposing the protected key value.
1881 : */
1882 : class SymmetricKeyContext
1883 : {
1884 : public:
1885 : /**
1886 : * @brief Returns the symmetric key hash
1887 : *
1888 : * TODO: Replace GetKeyHash() with DeriveGroupSessionId(SymmetricKeyContext &, uint16_t & session_id)
1889 : *
1890 : * @return Group Key Hash
1891 : */
1892 : virtual uint16_t GetKeyHash() = 0;
1893 :
1894 9 : virtual ~SymmetricKeyContext() = default;
1895 : /**
1896 : * @brief Perform the message encryption as described in 4.7.2. (Security Processing of Outgoing Messages)
1897 : * @param[in] plaintext Outgoing message payload.
1898 : * @param[in] aad Additional data (message header contents)
1899 : * @param[in] nonce Nonce (Security Flags | Message Counter | Source Node ID)
1900 : * @param[out] mic Outgoing Message Integrity Check
1901 : * @param[out] ciphertext Outgoing encrypted payload. Must be at least as big as plaintext. The same buffer may be used both
1902 : * for ciphertext, and plaintext.
1903 : * @return CHIP_ERROR
1904 : */
1905 : virtual CHIP_ERROR MessageEncrypt(const ByteSpan & plaintext, const ByteSpan & aad, const ByteSpan & nonce,
1906 : MutableByteSpan & mic, MutableByteSpan & ciphertext) const = 0;
1907 : /**
1908 : * @brief Perform the message decryption as described in 4.7.3.(Security Processing of Incoming Messages)
1909 : * @param[in] ciphertext Incoming encrypted payload
1910 : * @param[in] aad Additional data (message header contents)
1911 : * @param[in] nonce Nonce (Security Flags | Message Counter | Source Node ID)
1912 : * @param[in] mic Incoming Message Integrity Check
1913 : * @param[out] plaintext Incoming message payload. Must be at least as big as ciphertext. The same buffer may be used both
1914 : * for plaintext, and ciphertext.
1915 : * @return CHIP_ERROR
1916 : */
1917 : virtual CHIP_ERROR MessageDecrypt(const ByteSpan & ciphertext, const ByteSpan & aad, const ByteSpan & nonce,
1918 : const ByteSpan & mic, MutableByteSpan & plaintext) const = 0;
1919 :
1920 : /**
1921 : * @brief Perform privacy encoding as described in 4.8.2. (Privacy Processing of Outgoing Messages)
1922 : * @param[in] input Message header to privacy encrypt
1923 : * @param[in] nonce Privacy Nonce = session_id | mic
1924 : * @param[out] output Message header obfuscated
1925 : * @return CHIP_ERROR
1926 : */
1927 : virtual CHIP_ERROR PrivacyEncrypt(const ByteSpan & input, const ByteSpan & nonce, MutableByteSpan & output) const = 0;
1928 :
1929 : /**
1930 : * @brief Perform privacy decoding as described in 4.8.3. (Privacy Processing of Incoming Messages)
1931 : * @param[in] input Message header to privacy decrypt
1932 : * @param[in] nonce Privacy Nonce = session_id | mic
1933 : * @param[out] output Message header deobfuscated
1934 : * @return CHIP_ERROR
1935 : */
1936 : virtual CHIP_ERROR PrivacyDecrypt(const ByteSpan & input, const ByteSpan & nonce, MutableByteSpan & output) const = 0;
1937 :
1938 : /**
1939 : * @brief Release resources such as dynamic memory used to allocate this instance of the SymmetricKeyContext
1940 : */
1941 : virtual void Release() = 0;
1942 : };
1943 :
1944 : /**
1945 : * @brief Derives the Operational Group Key using the Key Derivation Function (KDF) from the given epoch key.
1946 : * @param[in] epoch_key The epoch key. Must be CHIP_CRYPTO_SYMMETRIC_KEY_LENGTH_BYTES bytes length.
1947 : * @param[in] compressed_fabric_id The compressed fabric ID for the fabric (big endian byte string)
1948 : * @param[out] out_key Symmetric key used as the encryption key during message processing for group communication.
1949 : The buffer size must be at least CHIP_CRYPTO_SYMMETRIC_KEY_LENGTH_BYTES bytes length.
1950 : * @return Returns a CHIP_NO_ERROR on succcess, or CHIP_ERROR_INTERNAL if the provided key is invalid.
1951 : **/
1952 : CHIP_ERROR DeriveGroupOperationalKey(const ByteSpan & epoch_key, const ByteSpan & compressed_fabric_id, MutableByteSpan & out_key);
1953 :
1954 : /**
1955 : * @brief Derives the Group Session ID from a given operational group key using
1956 : * the Key Derivation Function (Group Key Hash)
1957 : * @param[in] operational_key The operational group key. Must be CHIP_CRYPTO_SYMMETRIC_KEY_LENGTH_BYTES bytes length.
1958 : * @param[out] session_id Output of the Group Key Hash
1959 : * @return Returns a CHIP_NO_ERROR on succcess, or CHIP_ERROR_INVALID_ARGUMENT if the provided key is invalid.
1960 : **/
1961 : CHIP_ERROR DeriveGroupSessionId(const ByteSpan & operational_key, uint16_t & session_id);
1962 :
1963 : /**
1964 : * @brief Derives the Privacy Group Key using the Key Derivation Function (KDF) from the given epoch key.
1965 : * @param[in] epoch_key The epoch key. Must be CHIP_CRYPTO_SYMMETRIC_KEY_LENGTH_BYTES bytes length.
1966 : * @param[out] out_key Symmetric key used as the privacy key during message processing for group communication.
1967 : * The buffer size must be at least CHIP_CRYPTO_SYMMETRIC_KEY_LENGTH_BYTES bytes length.
1968 : * @return Returns a CHIP_NO_ERROR on succcess, or CHIP_ERROR_INTERNAL if the provided key is invalid.
1969 : **/
1970 : CHIP_ERROR DeriveGroupPrivacyKey(const ByteSpan & epoch_key, MutableByteSpan & out_key);
1971 :
1972 : /**
1973 : * @brief Derives the complete set of credentials needed for group security.
1974 : *
1975 : * This function will derive the Encryption Key, Group Key Hash (Session Id), and Privacy Key
1976 : * for the given Epoch Key and Compressed Fabric Id.
1977 : * @param[in] epoch_key The epoch key. Must be CHIP_CRYPTO_SYMMETRIC_KEY_LENGTH_BYTES bytes length.
1978 : * @param[in] compressed_fabric_id The compressed fabric ID for the fabric (big endian byte string)
1979 : * @param[out] operational_credentials The set of Symmetric keys used during message processing for group communication.
1980 : * @return Returns a CHIP_NO_ERROR on succcess, or CHIP_ERROR_INTERNAL if the provided key is invalid.
1981 : **/
1982 : CHIP_ERROR DeriveGroupOperationalCredentials(const ByteSpan & epoch_key, const ByteSpan & compressed_fabric_id,
1983 : GroupOperationalCredentials & operational_credentials);
1984 : } // namespace Crypto
1985 : } // namespace chip
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