diff --git a/src/platform/silabs/SiWx917/BUILD.gn b/src/platform/silabs/SiWx917/BUILD.gn index 7f361f313cd771..d53d04894869ce 100644 --- a/src/platform/silabs/SiWx917/BUILD.gn +++ b/src/platform/silabs/SiWx917/BUILD.gn @@ -27,6 +27,9 @@ if (chip_enable_openthread) { import("//build_overrides/openthread.gni") } +if (chip_crypto == "platform") { + import("//build_overrides/mbedtls.gni") +} static_library("SiWx917") { sources = [ "${silabs_platform_dir}/BLEManagerImpl.h", @@ -67,6 +70,15 @@ static_library("SiWx917") { public_deps = [ "${chip_root}/src/platform:platform_base" ] + # Add platform crypto implementation + if (chip_crypto == "platform") { + sources += [ "CHIPCryptoPALTinyCrypt.cpp" ] + public_deps += [ + "${chip_root}/src/crypto", + "${mbedtls_root}:mbedtls", + ] + } + if (chip_enable_wifi) { sources += [ "${silabs_platform_dir}/ConnectivityManagerImpl_WIFI.cpp", diff --git a/src/platform/silabs/SiWx917/CHIPCryptoPALTinyCrypt.cpp b/src/platform/silabs/SiWx917/CHIPCryptoPALTinyCrypt.cpp new file mode 100644 index 00000000000000..9f88a1937f8eb7 --- /dev/null +++ b/src/platform/silabs/SiWx917/CHIPCryptoPALTinyCrypt.cpp @@ -0,0 +1,1754 @@ +/* + * + * Copyright (c) 2020-2022 Project CHIP Authors + * + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +/** + * @file + * mbedTLS based implementation of CHIP crypto primitives + */ + +#include + +#include + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#if defined(MBEDTLS_X509_CRT_PARSE_C) +#include +#endif // defined(MBEDTLS_X509_CRT_PARSE_C) +#include +#include +#include + +#include +#include +#include +#include + +#include +#include +#include +#include +#include +#include +#include +#include + +#include + +namespace chip { +namespace Crypto { + +#define MAX_ERROR_STR_LEN 128 +#define NUM_BYTES_IN_SHA256_HASH 32 + +// In mbedTLS 3.0.0 direct access to structure fields was replaced with using MBEDTLS_PRIVATE macro. +#if (MBEDTLS_VERSION_NUMBER >= 0x03000000) +#define CHIP_CRYPTO_PAL_PRIVATE(x) MBEDTLS_PRIVATE(x) +#else +#define CHIP_CRYPTO_PAL_PRIVATE(x) x +#endif + +#if (MBEDTLS_VERSION_NUMBER >= 0x03000000 && MBEDTLS_VERSION_NUMBER < 0x03010000) +#define CHIP_CRYPTO_PAL_PRIVATE_X509(x) MBEDTLS_PRIVATE(x) +#else +#define CHIP_CRYPTO_PAL_PRIVATE_X509(x) x +#endif + +typedef struct +{ + bool mInitialized; + bool mDRBGSeeded; + mbedtls_ctr_drbg_context mDRBGCtxt; + mbedtls_entropy_context mEntropy; +} EntropyContext; + +static EntropyContext gsEntropyContext; + +static void _log_mbedTLS_error(int error_code) +{ + if (error_code != 0 && error_code != UECC_SUCCESS) + { +#if defined(MBEDTLS_ERROR_C) + char error_str[MAX_ERROR_STR_LEN]; + mbedtls_strerror(error_code, error_str, sizeof(error_str)); + ChipLogError(Crypto, "mbedTLS error: %s", error_str); +#else + // Error codes defined in 16-bit negative hex numbers. Ease lookup by printing likewise + ChipLogError(Crypto, "mbedTLS error: -0x%04X", -static_cast(error_code)); +#endif + } +} + +static bool _isValidTagLength(size_t tag_length) +{ + if (tag_length == 8 || tag_length == 12 || tag_length == 16) + { + return true; + } + return false; +} + +CHIP_ERROR AES_CCM_encrypt(const uint8_t * plaintext, size_t plaintext_length, const uint8_t * aad, size_t aad_length, + const Aes128KeyHandle & key, const uint8_t * nonce, size_t nonce_length, uint8_t * ciphertext, + uint8_t * tag, size_t tag_length) +{ + CHIP_ERROR error = CHIP_NO_ERROR; + int result = 1; + + mbedtls_ccm_context context; + mbedtls_ccm_init(&context); + + VerifyOrExit(plaintext != nullptr || plaintext_length == 0, error = CHIP_ERROR_INVALID_ARGUMENT); + VerifyOrExit(ciphertext != nullptr || plaintext_length == 0, error = CHIP_ERROR_INVALID_ARGUMENT); + VerifyOrExit(nonce != nullptr, error = CHIP_ERROR_INVALID_ARGUMENT); + VerifyOrExit(nonce_length > 0, error = CHIP_ERROR_INVALID_ARGUMENT); + VerifyOrExit(tag != nullptr, error = CHIP_ERROR_INVALID_ARGUMENT); + VerifyOrExit(_isValidTagLength(tag_length), error = CHIP_ERROR_INVALID_ARGUMENT); + if (aad_length > 0) + { + VerifyOrExit(aad != nullptr, error = CHIP_ERROR_INVALID_ARGUMENT); + } + + // multiplying by 8 to convert key from bits to byte + result = mbedtls_ccm_setkey(&context, MBEDTLS_CIPHER_ID_AES, key.As(), sizeof(Aes128KeyByteArray) * 8); + VerifyOrExit(result == 0, error = CHIP_ERROR_INTERNAL); + + // Encrypt + result = mbedtls_ccm_encrypt_and_tag(&context, plaintext_length, Uint8::to_const_uchar(nonce), nonce_length, + Uint8::to_const_uchar(aad), aad_length, Uint8::to_const_uchar(plaintext), + Uint8::to_uchar(ciphertext), Uint8::to_uchar(tag), tag_length); + _log_mbedTLS_error(result); + VerifyOrExit(result == 0, error = CHIP_ERROR_INTERNAL); + +exit: + mbedtls_ccm_free(&context); + return error; +} + +CHIP_ERROR AES_CCM_decrypt(const uint8_t * ciphertext, size_t ciphertext_len, const uint8_t * aad, size_t aad_len, + const uint8_t * tag, size_t tag_length, const Aes128KeyHandle & key, const uint8_t * nonce, + size_t nonce_length, uint8_t * plaintext) +{ + CHIP_ERROR error = CHIP_NO_ERROR; + int result = 1; + + mbedtls_ccm_context context; + mbedtls_ccm_init(&context); + + VerifyOrExit(plaintext != nullptr || ciphertext_len == 0, error = CHIP_ERROR_INVALID_ARGUMENT); + VerifyOrExit(ciphertext != nullptr || ciphertext_len == 0, error = CHIP_ERROR_INVALID_ARGUMENT); + VerifyOrExit(tag != nullptr, error = CHIP_ERROR_INVALID_ARGUMENT); + VerifyOrExit(_isValidTagLength(tag_length), error = CHIP_ERROR_INVALID_ARGUMENT); + VerifyOrExit(nonce != nullptr, error = CHIP_ERROR_INVALID_ARGUMENT); + VerifyOrExit(nonce_length > 0, error = CHIP_ERROR_INVALID_ARGUMENT); + if (aad_len > 0) + { + VerifyOrExit(aad != nullptr, error = CHIP_ERROR_INVALID_ARGUMENT); + } + + // multiplying by 8 to convert key from bits to byte + result = mbedtls_ccm_setkey(&context, MBEDTLS_CIPHER_ID_AES, key.As(), sizeof(Aes128KeyByteArray) * 8); + VerifyOrExit(result == 0, error = CHIP_ERROR_INTERNAL); + + // Decrypt + result = mbedtls_ccm_auth_decrypt(&context, ciphertext_len, Uint8::to_const_uchar(nonce), nonce_length, + Uint8::to_const_uchar(aad), aad_len, Uint8::to_const_uchar(ciphertext), + Uint8::to_uchar(plaintext), Uint8::to_const_uchar(tag), tag_length); + _log_mbedTLS_error(result); + VerifyOrExit(result == 0, error = CHIP_ERROR_INTERNAL); + +exit: + mbedtls_ccm_free(&context); + return error; +} + +CHIP_ERROR Hash_SHA256(const uint8_t * data, const size_t data_length, uint8_t * out_buffer) +{ + // zero data length hash is supported. + VerifyOrReturnError(data != nullptr, CHIP_ERROR_INVALID_ARGUMENT); + VerifyOrReturnError(out_buffer != nullptr, CHIP_ERROR_INVALID_ARGUMENT); + +#if (MBEDTLS_VERSION_NUMBER >= 0x03000000) + const int result = mbedtls_sha256(Uint8::to_const_uchar(data), data_length, Uint8::to_uchar(out_buffer), 0); +#else + const int result = mbedtls_sha256_ret(Uint8::to_const_uchar(data), data_length, Uint8::to_uchar(out_buffer), 0); +#endif + + VerifyOrReturnError(result == 0, CHIP_ERROR_INTERNAL); + + return CHIP_NO_ERROR; +} + +CHIP_ERROR Hash_SHA1(const uint8_t * data, const size_t data_length, uint8_t * out_buffer) +{ + // zero data length hash is supported. + VerifyOrReturnError(out_buffer != nullptr, CHIP_ERROR_INVALID_ARGUMENT); + +#if (MBEDTLS_VERSION_NUMBER >= 0x03000000) + const int result = mbedtls_sha1(Uint8::to_const_uchar(data), data_length, Uint8::to_uchar(out_buffer)); +#else + const int result = mbedtls_sha1_ret(Uint8::to_const_uchar(data), data_length, Uint8::to_uchar(out_buffer)); +#endif + + VerifyOrReturnError(result == 0, CHIP_ERROR_INTERNAL); + + return CHIP_NO_ERROR; +} + +static_assert(kMAX_Hash_SHA256_Context_Size >= sizeof(mbedtls_sha256_context), + "kMAX_Hash_SHA256_Context_Size is too small for the size of underlying mbedtls_sha256_context"); + +static inline mbedtls_sha256_context * to_inner_hash_sha256_context(HashSHA256OpaqueContext * context) +{ + return SafePointerCast(context); +} + +Hash_SHA256_stream::Hash_SHA256_stream(void) +{ + mbedtls_sha256_context * context = to_inner_hash_sha256_context(&mContext); + mbedtls_sha256_init(context); +} + +Hash_SHA256_stream::~Hash_SHA256_stream(void) +{ + mbedtls_sha256_context * context = to_inner_hash_sha256_context(&mContext); + mbedtls_sha256_free(context); + Clear(); +} + +CHIP_ERROR Hash_SHA256_stream::Begin(void) +{ + mbedtls_sha256_context * const context = to_inner_hash_sha256_context(&mContext); + +#if (MBEDTLS_VERSION_NUMBER >= 0x03000000) + const int result = mbedtls_sha256_starts(context, 0); +#else + const int result = mbedtls_sha256_starts_ret(context, 0); +#endif + + VerifyOrReturnError(result == 0, CHIP_ERROR_INTERNAL); + + return CHIP_NO_ERROR; +} + +CHIP_ERROR Hash_SHA256_stream::AddData(const ByteSpan data) +{ + mbedtls_sha256_context * const context = to_inner_hash_sha256_context(&mContext); + +#if (MBEDTLS_VERSION_NUMBER >= 0x03000000) + const int result = mbedtls_sha256_update(context, Uint8::to_const_uchar(data.data()), data.size()); +#else + const int result = mbedtls_sha256_update_ret(context, Uint8::to_const_uchar(data.data()), data.size()); +#endif + + VerifyOrReturnError(result == 0, CHIP_ERROR_INTERNAL); + + return CHIP_NO_ERROR; +} + +CHIP_ERROR Hash_SHA256_stream::GetDigest(MutableByteSpan & out_buffer) +{ + mbedtls_sha256_context * context = to_inner_hash_sha256_context(&mContext); + + // Back-up context as we are about to finalize the hash to extract digest. + mbedtls_sha256_context previous_ctx; + mbedtls_sha256_init(&previous_ctx); + mbedtls_sha256_clone(&previous_ctx, context); + + // Pad + compute digest, then finalize context. It is restored next line to continue. + CHIP_ERROR result = Finish(out_buffer); + + // Restore context prior to finalization. + mbedtls_sha256_clone(context, &previous_ctx); + mbedtls_sha256_free(&previous_ctx); + + return result; +} + +CHIP_ERROR Hash_SHA256_stream::Finish(MutableByteSpan & out_buffer) +{ + VerifyOrReturnError(out_buffer.size() >= kSHA256_Hash_Length, CHIP_ERROR_BUFFER_TOO_SMALL); + mbedtls_sha256_context * const context = to_inner_hash_sha256_context(&mContext); + +#if (MBEDTLS_VERSION_NUMBER >= 0x03000000) + const int result = mbedtls_sha256_finish(context, Uint8::to_uchar(out_buffer.data())); +#else + const int result = mbedtls_sha256_finish_ret(context, Uint8::to_uchar(out_buffer.data())); +#endif + + VerifyOrReturnError(result == 0, CHIP_ERROR_INTERNAL); + out_buffer = out_buffer.SubSpan(0, kSHA256_Hash_Length); + + return CHIP_NO_ERROR; +} + +void Hash_SHA256_stream::Clear(void) +{ + mbedtls_platform_zeroize(this, sizeof(*this)); +} + +CHIP_ERROR HKDF_sha::HKDF_SHA256(const uint8_t * secret, const size_t secret_length, const uint8_t * salt, const size_t salt_length, + const uint8_t * info, const size_t info_length, uint8_t * out_buffer, size_t out_length) +{ + VerifyOrReturnError(secret != nullptr, CHIP_ERROR_INVALID_ARGUMENT); + VerifyOrReturnError(secret_length > 0, CHIP_ERROR_INVALID_ARGUMENT); + + // Salt is optional + if (salt_length > 0) + { + VerifyOrReturnError(salt != nullptr, CHIP_ERROR_INVALID_ARGUMENT); + } + + VerifyOrReturnError(info_length > 0, CHIP_ERROR_INVALID_ARGUMENT); + VerifyOrReturnError(info != nullptr, CHIP_ERROR_INVALID_ARGUMENT); + VerifyOrReturnError(out_length > 0, CHIP_ERROR_INVALID_ARGUMENT); + VerifyOrReturnError(out_buffer != nullptr, CHIP_ERROR_INVALID_ARGUMENT); + + const mbedtls_md_info_t * const md = mbedtls_md_info_from_type(MBEDTLS_MD_SHA256); + VerifyOrReturnError(md != nullptr, CHIP_ERROR_INTERNAL); + + const int result = mbedtls_hkdf(md, Uint8::to_const_uchar(salt), salt_length, Uint8::to_const_uchar(secret), secret_length, + Uint8::to_const_uchar(info), info_length, Uint8::to_uchar(out_buffer), out_length); + _log_mbedTLS_error(result); + VerifyOrReturnError(result == 0, CHIP_ERROR_INTERNAL); + + return CHIP_NO_ERROR; +} + +CHIP_ERROR HMAC_sha::HMAC_SHA256(const uint8_t * key, size_t key_length, const uint8_t * message, size_t message_length, + uint8_t * out_buffer, size_t out_length) +{ + VerifyOrReturnError(key != nullptr, CHIP_ERROR_INVALID_ARGUMENT); + VerifyOrReturnError(key_length > 0, CHIP_ERROR_INVALID_ARGUMENT); + VerifyOrReturnError(message != nullptr, CHIP_ERROR_INVALID_ARGUMENT); + VerifyOrReturnError(message_length > 0, CHIP_ERROR_INVALID_ARGUMENT); + VerifyOrReturnError(out_length >= kSHA256_Hash_Length, CHIP_ERROR_INVALID_ARGUMENT); + VerifyOrReturnError(out_buffer != nullptr, CHIP_ERROR_INVALID_ARGUMENT); + + const mbedtls_md_info_t * const md = mbedtls_md_info_from_type(MBEDTLS_MD_SHA256); + VerifyOrReturnError(md != nullptr, CHIP_ERROR_INTERNAL); + + const int result = + mbedtls_md_hmac(md, Uint8::to_const_uchar(key), key_length, Uint8::to_const_uchar(message), message_length, out_buffer); + + _log_mbedTLS_error(result); + VerifyOrReturnError(result == 0, CHIP_ERROR_INTERNAL); + + return CHIP_NO_ERROR; +} + +CHIP_ERROR PBKDF2_sha256::pbkdf2_sha256(const uint8_t * password, size_t plen, const uint8_t * salt, size_t slen, + unsigned int iteration_count, uint32_t key_length, uint8_t * output) +{ + CHIP_ERROR error = CHIP_NO_ERROR; + int result = 0; + const mbedtls_md_info_t * md_info; + mbedtls_md_context_t md_ctxt; + constexpr int use_hmac = 1; + + bool free_md_ctxt = false; + + VerifyOrExit(password != nullptr, error = CHIP_ERROR_INVALID_ARGUMENT); + VerifyOrExit(plen > 0, error = CHIP_ERROR_INVALID_ARGUMENT); + VerifyOrExit(salt != nullptr, error = CHIP_ERROR_INVALID_ARGUMENT); + VerifyOrExit(slen >= kSpake2p_Min_PBKDF_Salt_Length, error = CHIP_ERROR_INVALID_ARGUMENT); + VerifyOrExit(slen <= kSpake2p_Max_PBKDF_Salt_Length, error = CHIP_ERROR_INVALID_ARGUMENT); + VerifyOrExit(key_length > 0, error = CHIP_ERROR_INVALID_ARGUMENT); + VerifyOrExit(output != nullptr, error = CHIP_ERROR_INVALID_ARGUMENT); + + md_info = mbedtls_md_info_from_type(MBEDTLS_MD_SHA256); + VerifyOrExit(md_info != nullptr, error = CHIP_ERROR_INTERNAL); + + mbedtls_md_init(&md_ctxt); + free_md_ctxt = true; + + result = mbedtls_md_setup(&md_ctxt, md_info, use_hmac); + VerifyOrExit(result == 0, error = CHIP_ERROR_INTERNAL); + + result = mbedtls_pkcs5_pbkdf2_hmac(&md_ctxt, Uint8::to_const_uchar(password), plen, Uint8::to_const_uchar(salt), slen, + iteration_count, key_length, Uint8::to_uchar(output)); + + VerifyOrExit(result == 0, error = CHIP_ERROR_INTERNAL); + +exit: + _log_mbedTLS_error(result); + + if (free_md_ctxt) + { + mbedtls_md_free(&md_ctxt); + } + + return error; +} + +static EntropyContext * get_entropy_context() +{ + if (!gsEntropyContext.mInitialized) + { + mbedtls_entropy_init(&gsEntropyContext.mEntropy); + mbedtls_ctr_drbg_init(&gsEntropyContext.mDRBGCtxt); + + gsEntropyContext.mInitialized = true; + } + + return &gsEntropyContext; +} + +static mbedtls_ctr_drbg_context * get_drbg_context() +{ + EntropyContext * const context = get_entropy_context(); + + mbedtls_ctr_drbg_context * const drbgCtxt = &context->mDRBGCtxt; + + if (!context->mDRBGSeeded) + { + const int status = mbedtls_ctr_drbg_seed(drbgCtxt, mbedtls_entropy_func, &context->mEntropy, nullptr, 0); + if (status != 0) + { + _log_mbedTLS_error(status); + return nullptr; + } + + context->mDRBGSeeded = true; + } + + return drbgCtxt; +} + +CHIP_ERROR add_entropy_source(entropy_source fn_source, void * p_source, size_t threshold) +{ + VerifyOrReturnError(fn_source != nullptr, CHIP_ERROR_INVALID_ARGUMENT); + + EntropyContext * const entropy_ctxt = get_entropy_context(); + VerifyOrReturnError(entropy_ctxt != nullptr, CHIP_ERROR_INTERNAL); + + const int result = + mbedtls_entropy_add_source(&entropy_ctxt->mEntropy, fn_source, p_source, threshold, MBEDTLS_ENTROPY_SOURCE_STRONG); + VerifyOrReturnError(result == 0, CHIP_ERROR_INTERNAL); + return CHIP_NO_ERROR; +} + +CHIP_ERROR DRBG_get_bytes(uint8_t * out_buffer, const size_t out_length) +{ + VerifyOrReturnError(out_buffer != nullptr, CHIP_ERROR_INVALID_ARGUMENT); + VerifyOrReturnError(out_length > 0, CHIP_ERROR_INVALID_ARGUMENT); + + mbedtls_ctr_drbg_context * const drbg_ctxt = get_drbg_context(); + VerifyOrReturnError(drbg_ctxt != nullptr, CHIP_ERROR_INTERNAL); + + const int result = mbedtls_ctr_drbg_random(drbg_ctxt, Uint8::to_uchar(out_buffer), out_length); + VerifyOrReturnError(result == 0, CHIP_ERROR_INTERNAL); + + return CHIP_NO_ERROR; +} + +static int CryptoRNG(void * ctxt, uint8_t * out_buffer, size_t out_length) +{ + return (chip::Crypto::DRBG_get_bytes(out_buffer, out_length) == CHIP_NO_ERROR) ? 0 : 1; +} + +mbedtls_ecp_group_id MapECPGroupId(SupportedECPKeyTypes keyType) +{ + switch (keyType) + { + case SupportedECPKeyTypes::ECP256R1: + return MBEDTLS_ECP_DP_SECP256R1; + default: + return MBEDTLS_ECP_DP_NONE; + } +} + +static inline mbedtls_uecc_keypair * to_keypair(P256KeypairContext * context) +{ + return SafePointerCast(context); +} + +static inline const mbedtls_uecc_keypair * to_const_keypair(const P256KeypairContext * context) +{ + return SafePointerCast(context); +} + +CHIP_ERROR P256Keypair::ECDSA_sign_msg(const uint8_t * msg, const size_t msg_length, P256ECDSASignature & out_signature) const +{ + VerifyOrReturnError(mInitialized, CHIP_ERROR_WELL_UNINITIALIZED); + VerifyOrReturnError((msg != nullptr) && (msg_length > 0), CHIP_ERROR_INVALID_ARGUMENT); + + uint8_t digest[kSHA256_Hash_Length]; + memset(&digest[0], 0, sizeof(digest)); + ReturnErrorOnFailure(Hash_SHA256(msg, msg_length, &digest[0])); + + CHIP_ERROR error = CHIP_NO_ERROR; + int result = UECC_FAILURE; + + const mbedtls_uecc_keypair * keypair = to_const_keypair(&mKeypair); + + result = uECC_sign(keypair->private_key, digest, sizeof(digest), out_signature.Bytes()); + + VerifyOrExit(result == UECC_SUCCESS, error = CHIP_ERROR_INTERNAL); + VerifyOrExit(out_signature.SetLength(kP256_ECDSA_Signature_Length_Raw) == CHIP_NO_ERROR, error = CHIP_ERROR_INTERNAL); + + keypair = nullptr; + +exit: + return error; +} + +CHIP_ERROR P256PublicKey::ECDSA_validate_msg_signature(const uint8_t * msg, const size_t msg_length, + const P256ECDSASignature & signature) const +{ +#if defined(MBEDTLS_ECDSA_C) + VerifyOrReturnError((msg != nullptr) && (msg_length > 0), CHIP_ERROR_INVALID_ARGUMENT); + + uint8_t digest[kSHA256_Hash_Length]; + memset(&digest[0], 0, sizeof(digest)); + ReturnErrorOnFailure(Hash_SHA256(msg, msg_length, &digest[0])); + + return ECDSA_validate_hash_signature(&digest[0], sizeof(digest), signature); +#else + return CHIP_ERROR_NOT_IMPLEMENTED; +#endif +} + +CHIP_ERROR P256PublicKey::ECDSA_validate_hash_signature(const uint8_t * hash, const size_t hash_length, + const P256ECDSASignature & signature) const +{ + VerifyOrReturnError(hash != nullptr, CHIP_ERROR_INVALID_ARGUMENT); + VerifyOrReturnError(hash_length == kSHA256_Hash_Length, CHIP_ERROR_INVALID_ARGUMENT); + VerifyOrReturnError(signature.Length() == kP256_ECDSA_Signature_Length_Raw, CHIP_ERROR_INVALID_ARGUMENT); + + CHIP_ERROR error = CHIP_NO_ERROR; + int result = UECC_FAILURE; + + const uint8_t * public_key = *this; + + // Fully padded raw uncompressed points expected, first byte is always 0x04 i.e uncompressed + result = uECC_verify(public_key + 1, hash, hash_length, Uint8::to_const_uchar(signature.ConstBytes())); + VerifyOrExit(result == UECC_SUCCESS, error = CHIP_ERROR_INVALID_SIGNATURE); + +exit: + return error; +} + +CHIP_ERROR P256Keypair::ECDH_derive_secret(const P256PublicKey & remote_public_key, P256ECDHDerivedSecret & out_secret) const +{ +#if defined(MBEDTLS_ECDH_C) + CHIP_ERROR error = CHIP_NO_ERROR; + int result = 0; + size_t secret_length = (out_secret.Length() == 0) ? out_secret.Capacity() : out_secret.Length(); + + const mbedtls_uecc_keypair * keypair = to_const_keypair(&mKeypair); + + VerifyOrExit(mInitialized, error = CHIP_ERROR_WELL_UNINITIALIZED); + + // Fully padded raw uncompressed points expected, first byte is always 0x04 i.e uncompressed + result = uECC_shared_secret(remote_public_key.ConstBytes() + 1, keypair->private_key, out_secret.Bytes()); + VerifyOrExit(result == UECC_SUCCESS, error = CHIP_ERROR_INTERNAL); + + SuccessOrExit(out_secret.SetLength(secret_length)); + +exit: + keypair = nullptr; + _log_mbedTLS_error(result); + return error; +#else + return CHIP_ERROR_NOT_IMPLEMENTED; +#endif +} + +void ClearSecretData(uint8_t * buf, size_t len) +{ + mbedtls_platform_zeroize(buf, len); +} + +// THE BELOW IS FROM `third_party/openthread/repo/third_party/mbedtls/repo/library/constant_time.c` since +// mbedtls_ct_memcmp is not available on Linux somehow :( +int mbedtls_ct_memcmp_copy(const void * a, const void * b, size_t n) +{ + size_t i; + volatile const unsigned char * A = (volatile const unsigned char *) a; + volatile const unsigned char * B = (volatile const unsigned char *) b; + volatile unsigned char diff = 0; + + for (i = 0; i < n; i++) + { + /* Read volatile data in order before computing diff. + * This avoids IAR compiler warning: + * 'the order of volatile accesses is undefined ..' */ + unsigned char x = A[i], y = B[i]; + diff |= x ^ y; + } + + return ((int) diff); +} + +bool IsBufferContentEqualConstantTime(const void * a, const void * b, size_t n) +{ + return mbedtls_ct_memcmp_copy(a, b, n) == 0; +} + +CHIP_ERROR P256Keypair::Initialize(ECPKeyTarget key_target) +{ + CHIP_ERROR error = CHIP_NO_ERROR; + int result = UECC_FAILURE; + + Clear(); + + mbedtls_uecc_keypair * keypair = to_keypair(&mKeypair); + + result = uECC_make_key(keypair->public_key, keypair->private_key); + VerifyOrExit(result == UECC_SUCCESS, error = CHIP_ERROR_INTERNAL); + + // Fully padded raw uncompressed points expected, first byte is always 0x04 i.e uncompressed + Uint8::to_uchar(mPublicKey)[0] = 0x04; + memcpy(Uint8::to_uchar(mPublicKey) + 1, keypair->public_key, 2 * NUM_ECC_BYTES); + + keypair = nullptr; + mInitialized = true; + +exit: + _log_mbedTLS_error(result); + return error; +} + +CHIP_ERROR P256Keypair::Serialize(P256SerializedKeypair & output) const +{ + const mbedtls_uecc_keypair * keypair = to_const_keypair(&mKeypair); + size_t len = output.Length() == 0 ? output.Capacity() : output.Length(); + Encoding::BufferWriter bbuf(output.Bytes(), len); + uint8_t privkey[kP256_PrivateKey_Length]; + CHIP_ERROR error = CHIP_NO_ERROR; + int result = 0; + + bbuf.Put(mPublicKey, mPublicKey.Length()); + + VerifyOrExit(bbuf.Available() == sizeof(privkey), error = CHIP_ERROR_INTERNAL); + VerifyOrExit(sizeof(keypair->private_key) <= bbuf.Available(), error = CHIP_ERROR_INTERNAL); + + memcpy(privkey, keypair->private_key, sizeof(privkey)); + + bbuf.Put(privkey, sizeof(privkey)); + VerifyOrExit(bbuf.Fit(), error = CHIP_ERROR_BUFFER_TOO_SMALL); + + output.SetLength(bbuf.Needed()); + +exit: + memset(privkey, 0, sizeof(privkey)); + _log_mbedTLS_error(result); + return error; +} + +CHIP_ERROR P256Keypair::Deserialize(P256SerializedKeypair & input) +{ + int result = 0; + CHIP_ERROR error = CHIP_NO_ERROR; + Encoding::BufferWriter bbuf(mPublicKey, mPublicKey.Length()); + + Clear(); + + mbedtls_uecc_keypair * keypair = to_keypair(&mKeypair); + + // Fully padded raw uncompressed points expected, first byte is always 0x04 i.e uncompressed + memcpy(keypair->public_key, input.ConstBytes() + 1, 2 * NUM_ECC_BYTES); + memcpy(keypair->private_key, input.ConstBytes() + mPublicKey.Length(), NUM_ECC_BYTES); + + keypair = nullptr; + + VerifyOrExit(input.Length() == mPublicKey.Length() + kP256_PrivateKey_Length, error = CHIP_ERROR_INVALID_ARGUMENT); + bbuf.Put(input.ConstBytes(), mPublicKey.Length()); + VerifyOrExit(bbuf.Fit(), error = CHIP_ERROR_NO_MEMORY); + + mInitialized = true; + + _log_mbedTLS_error(result); + +exit: + return error; +} + +void P256Keypair::Clear() +{ + if (mInitialized) + { + mbedtls_uecc_keypair * keypair = to_keypair(&mKeypair); + memset(keypair, 0, sizeof(mbedtls_uecc_keypair)); + mInitialized = false; + } +} + +P256Keypair::~P256Keypair() +{ + Clear(); +} + +CHIP_ERROR P256Keypair::NewCertificateSigningRequest(uint8_t * out_csr, size_t & csr_length) const +{ + CHIP_ERROR error = CHIP_NO_ERROR; + int result = 0; + size_t out_length; + + mbedtls_x509write_csr csr; + mbedtls_x509write_csr_init(&csr); + + mbedtls_pk_context pk; + pk.CHIP_CRYPTO_PAL_PRIVATE(pk_info) = mbedtls_pk_info_from_type(MBEDTLS_PK_ECKEY); + pk.CHIP_CRYPTO_PAL_PRIVATE(pk_ctx) = to_keypair(&mKeypair); + VerifyOrExit(pk.CHIP_CRYPTO_PAL_PRIVATE(pk_info) != nullptr, error = CHIP_ERROR_INTERNAL); + + VerifyOrExit(mInitialized, error = CHIP_ERROR_WELL_UNINITIALIZED); + + mbedtls_x509write_csr_set_key(&csr, &pk); + + mbedtls_x509write_csr_set_md_alg(&csr, MBEDTLS_MD_SHA256); + + // TODO: mbedTLS CSR parser fails if the subject name is not set (or if empty). + // CHIP Spec doesn't specify the subject name that can be used. + // Figure out the correct value and update this code. + result = mbedtls_x509write_csr_set_subject_name(&csr, "O=CSR"); + VerifyOrExit(result == 0, error = CHIP_ERROR_INTERNAL); + + result = mbedtls_x509write_csr_der(&csr, out_csr, csr_length, CryptoRNG, nullptr); + VerifyOrExit(result > 0, error = CHIP_ERROR_INTERNAL); + VerifyOrExit(CanCastTo(result), error = CHIP_ERROR_INTERNAL); + + out_length = static_cast(result); + result = 0; + VerifyOrExit(out_length <= csr_length, error = CHIP_ERROR_INTERNAL); + + if (csr_length != out_length) + { + // mbedTLS API writes the CSR at the end of the provided buffer. + // Let's move it to the start of the buffer. + size_t offset = csr_length - out_length; + memmove(out_csr, &out_csr[offset], out_length); + } + + csr_length = out_length; + +exit: + mbedtls_x509write_csr_free(&csr); + + _log_mbedTLS_error(result); + return error; +} + +CHIP_ERROR VerifyCertificateSigningRequest(const uint8_t * csr_buf, size_t csr_length, P256PublicKey & pubkey) +{ +#if defined(MBEDTLS_X509_CSR_PARSE_C) + ReturnErrorOnFailure(VerifyCertificateSigningRequestFormat(csr_buf, csr_length)); + + // TODO: For some embedded targets, mbedTLS library doesn't have mbedtls_x509_csr_parse_der, and mbedtls_x509_csr_parse_free. + // Taking a step back, embedded targets likely will not process CSR requests. Adding this action item to reevaluate + // this if there's a need for this processing for embedded targets. + CHIP_ERROR error = CHIP_NO_ERROR; + size_t pubkey_size = 0; + + mbedtls_ecp_keypair * keypair = nullptr; + + P256ECDSASignature signature; + MutableByteSpan out_raw_sig_span(signature.Bytes(), signature.Capacity()); + + mbedtls_x509_csr csr; + mbedtls_x509_csr_init(&csr); + + int result = mbedtls_x509_csr_parse_der(&csr, csr_buf, csr_length); + VerifyOrExit(result == 0, error = CHIP_ERROR_INTERNAL); + + // Verify the signature algorithm and public key type + VerifyOrExit(csr.CHIP_CRYPTO_PAL_PRIVATE(sig_md) == MBEDTLS_MD_SHA256, error = CHIP_ERROR_UNSUPPORTED_SIGNATURE_TYPE); + VerifyOrExit(csr.CHIP_CRYPTO_PAL_PRIVATE(sig_pk) == MBEDTLS_PK_ECDSA, error = CHIP_ERROR_WRONG_KEY_TYPE); + + keypair = mbedtls_pk_ec(csr.CHIP_CRYPTO_PAL_PRIVATE_X509(pk)); + + // Copy the public key from the CSR + result = mbedtls_ecp_point_write_binary(&keypair->CHIP_CRYPTO_PAL_PRIVATE(grp), &keypair->CHIP_CRYPTO_PAL_PRIVATE(Q), + MBEDTLS_ECP_PF_UNCOMPRESSED, &pubkey_size, Uint8::to_uchar(pubkey), pubkey.Length()); + + VerifyOrExit(result == 0, error = CHIP_ERROR_INTERNAL); + VerifyOrExit(pubkey_size == pubkey.Length(), error = CHIP_ERROR_INTERNAL); + + // Convert DER signature to raw signature + error = EcdsaAsn1SignatureToRaw(kP256_FE_Length, + ByteSpan{ csr.CHIP_CRYPTO_PAL_PRIVATE(sig).CHIP_CRYPTO_PAL_PRIVATE_X509(p), + csr.CHIP_CRYPTO_PAL_PRIVATE(sig).CHIP_CRYPTO_PAL_PRIVATE_X509(len) }, + out_raw_sig_span); + + VerifyOrExit(error == CHIP_NO_ERROR, error = CHIP_ERROR_INVALID_ARGUMENT); + VerifyOrExit(out_raw_sig_span.size() == (kP256_FE_Length * 2), error = CHIP_ERROR_INTERNAL); + signature.SetLength(out_raw_sig_span.size()); + + // Verify the signature using the public key + error = pubkey.ECDSA_validate_msg_signature(csr.CHIP_CRYPTO_PAL_PRIVATE_X509(cri).CHIP_CRYPTO_PAL_PRIVATE_X509(p), + csr.CHIP_CRYPTO_PAL_PRIVATE_X509(cri).CHIP_CRYPTO_PAL_PRIVATE_X509(len), signature); + + SuccessOrExit(error); + +exit: + mbedtls_x509_csr_free(&csr); + _log_mbedTLS_error(result); + return error; +#else + ChipLogError(Crypto, "MBEDTLS_X509_CSR_PARSE_C is not enabled. CSR cannot be parsed"); + return CHIP_ERROR_UNSUPPORTED_CHIP_FEATURE; +#endif +} + +typedef struct Spake2p_Context +{ + const mbedtls_md_info_t * md_info; + uECC_word_t M[2 * NUM_ECC_WORDS]; + uECC_word_t N[2 * NUM_ECC_WORDS]; + uECC_word_t X[2 * NUM_ECC_WORDS]; + uECC_word_t Y[2 * NUM_ECC_WORDS]; + uECC_word_t L[2 * NUM_ECC_WORDS]; + uECC_word_t Z[2 * NUM_ECC_WORDS]; + uECC_word_t V[2 * NUM_ECC_WORDS]; + + uECC_word_t w0[NUM_ECC_WORDS]; + uECC_word_t w1[NUM_ECC_WORDS]; + uECC_word_t xy[NUM_ECC_WORDS]; + uECC_word_t tempbn[NUM_ECC_WORDS]; +} Spake2p_Context; + +static inline Spake2p_Context * to_inner_spake2p_context(Spake2pOpaqueContext * context) +{ + return SafePointerCast(context); +} + +CHIP_ERROR Spake2p_P256_SHA256_HKDF_HMAC::InitInternal(void) +{ + CHIP_ERROR error = CHIP_NO_ERROR; + int result = 0; + + Spake2p_Context * context = to_inner_spake2p_context(&mSpake2pContext); + + memset(context, 0, sizeof(Spake2p_Context)); + + M = context->M; + N = context->N; + X = context->X; + Y = context->Y; + L = context->L; + V = context->V; + Z = context->Z; + + w0 = context->w0; + w1 = context->w1; + xy = context->xy; + tempbn = context->tempbn; + + G = curve_G; + + return error; + +exit: + _log_mbedTLS_error(result); + Clear(); + return error; +} + +void Spake2p_P256_SHA256_HKDF_HMAC::Clear() +{ + VerifyOrReturn(state != CHIP_SPAKE2P_STATE::PREINIT); + + Spake2p_Context * context = to_inner_spake2p_context(&mSpake2pContext); + memset(&context->M, 0, 2 * NUM_ECC_WORDS * sizeof(uECC_word_t)); + memset(&context->N, 0, 2 * NUM_ECC_WORDS * sizeof(uECC_word_t)); + memset(&context->X, 0, 2 * NUM_ECC_WORDS * sizeof(uECC_word_t)); + memset(&context->Y, 0, 2 * NUM_ECC_WORDS * sizeof(uECC_word_t)); + memset(&context->L, 0, 2 * NUM_ECC_WORDS * sizeof(uECC_word_t)); + memset(&context->Z, 0, 2 * NUM_ECC_WORDS * sizeof(uECC_word_t)); + memset(&context->V, 0, 2 * NUM_ECC_WORDS * sizeof(uECC_word_t)); + + memset(&context->w0, 0, NUM_ECC_WORDS * sizeof(uECC_word_t)); + memset(&context->w1, 0, NUM_ECC_WORDS * sizeof(uECC_word_t)); + memset(&context->xy, 0, NUM_ECC_WORDS * sizeof(uECC_word_t)); + memset(&context->tempbn, 0, NUM_ECC_WORDS * sizeof(uECC_word_t)); + + G = NULL; + state = CHIP_SPAKE2P_STATE::PREINIT; +} + +CHIP_ERROR Spake2p_P256_SHA256_HKDF_HMAC::Mac(const uint8_t * key, size_t key_len, const uint8_t * in, size_t in_len, + MutableByteSpan & out_span) +{ + HMAC_sha hmac; + VerifyOrReturnError(out_span.size() >= kSHA256_Hash_Length, CHIP_ERROR_BUFFER_TOO_SMALL); + ReturnErrorOnFailure(hmac.HMAC_SHA256(key, key_len, in, in_len, out_span.data(), kSHA256_Hash_Length)); + out_span = out_span.SubSpan(0, kSHA256_Hash_Length); + return CHIP_NO_ERROR; +} + +CHIP_ERROR Spake2p_P256_SHA256_HKDF_HMAC::MacVerify(const uint8_t * key, size_t key_len, const uint8_t * mac, size_t mac_len, + const uint8_t * in, size_t in_len) +{ + CHIP_ERROR error = CHIP_NO_ERROR; + int result = 0; + + uint8_t computed_mac[kSHA256_Hash_Length]; + MutableByteSpan computed_mac_span{ computed_mac }; + VerifyOrExit(mac_len == kSHA256_Hash_Length, error = CHIP_ERROR_INVALID_ARGUMENT); + + SuccessOrExit(error = Mac(key, key_len, in, in_len, computed_mac_span)); + VerifyOrExit(computed_mac_span.size() == mac_len, error = CHIP_ERROR_INTERNAL); + + VerifyOrExit(IsBufferContentEqualConstantTime(mac, computed_mac, kSHA256_Hash_Length), error = CHIP_ERROR_INTERNAL); + +exit: + _log_mbedTLS_error(result); + return error; +} + +CHIP_ERROR Spake2p_P256_SHA256_HKDF_HMAC::FELoad(const uint8_t * in, size_t in_len, void * fe) +{ + CHIP_ERROR error = CHIP_NO_ERROR; + int result = 0; + + uECC_word_t tmp[2 * NUM_ECC_WORDS] = { 0 }; + uECC_vli_bytesToNative(tmp, in, NUM_ECC_BYTES); + + uECC_vli_mmod((uECC_word_t *) fe, tmp, curve_n); + +exit: + _log_mbedTLS_error(result); + return error; +} + +CHIP_ERROR Spake2p_P256_SHA256_HKDF_HMAC::FEWrite(const void * fe, uint8_t * out, size_t out_len) +{ + uECC_vli_nativeToBytes(out, NUM_ECC_BYTES, (const unsigned int *) fe); + + return CHIP_NO_ERROR; +} + +CHIP_ERROR Spake2p_P256_SHA256_HKDF_HMAC::FEGenerate(void * fe) +{ + CHIP_ERROR error = CHIP_NO_ERROR; + int result = 0; + + mbedtls_uecc_keypair keypair; + + result = UECC_FAILURE; + + result = uECC_make_key(keypair.public_key, keypair.private_key); + VerifyOrExit(result == UECC_SUCCESS, error = CHIP_ERROR_INTERNAL); + + uECC_vli_bytesToNative((uECC_word_t *) fe, keypair.private_key, NUM_ECC_BYTES); + +exit: + _log_mbedTLS_error(result); + return error; +} + +CHIP_ERROR Spake2p_P256_SHA256_HKDF_HMAC::FEMul(void * fer, const void * fe1, const void * fe2) +{ + CHIP_ERROR error = CHIP_NO_ERROR; + int result = 0; + + uECC_vli_modMult((uECC_word_t *) fer, (const uECC_word_t *) fe1, (const uECC_word_t *) fe2, (const uECC_word_t *) curve_n); + +exit: + _log_mbedTLS_error(result); + return error; +} + +CHIP_ERROR Spake2p_P256_SHA256_HKDF_HMAC::PointLoad(const uint8_t * in, size_t in_len, void * R) +{ + uint8_t tmp[2 * NUM_ECC_BYTES]; + + // Fully padded raw uncompressed points expected, first byte is always 0x04 i.e uncompressed + memcpy(tmp, in + 1, 2 * NUM_ECC_BYTES); + + uECC_vli_bytesToNative((uECC_word_t *) R, tmp, NUM_ECC_BYTES); + uECC_vli_bytesToNative((uECC_word_t *) R + NUM_ECC_WORDS, tmp + NUM_ECC_BYTES, NUM_ECC_BYTES); + + return CHIP_NO_ERROR; +} + +CHIP_ERROR Spake2p_P256_SHA256_HKDF_HMAC::PointWrite(const void * R, uint8_t * out, size_t out_len) +{ + memset(out, 0, out_len); + + // Fully padded raw uncompressed points expected, first byte is always 0x04 i.e uncompressed + out[0] = 0x04; + uECC_vli_nativeToBytes(out + 1, NUM_ECC_BYTES, (uECC_word_t *) R); + uECC_vli_nativeToBytes(out + NUM_ECC_BYTES + 1, NUM_ECC_BYTES, (uECC_word_t *) R + NUM_ECC_WORDS); + + return CHIP_NO_ERROR; +} + +CHIP_ERROR Spake2p_P256_SHA256_HKDF_HMAC::PointMul(void * R, const void * P1, const void * fe1) +{ + + if (EccPoint_mult_safer((uECC_word_t *) R, (const uECC_word_t *) P1, (const uECC_word_t *) fe1) != UECC_SUCCESS) + { + return CHIP_ERROR_INTERNAL; + } + + return CHIP_NO_ERROR; +} + +CHIP_ERROR Spake2p_P256_SHA256_HKDF_HMAC::PointAddMul(void * R, const void * P1, const void * fe1, const void * P2, + const void * fe2) +{ + uECC_word_t R1[2 * NUM_ECC_WORDS]; + uECC_word_t R2[2 * NUM_ECC_WORDS]; + uECC_word_t z[NUM_ECC_WORDS]; + uint8_t ret = UECC_SUCCESS; + + if (EccPoint_mult_safer(R1, (const uECC_word_t *) P1, (const uECC_word_t *) fe1) != UECC_SUCCESS) + { + return CHIP_ERROR_INTERNAL; + } + + if (EccPoint_mult_safer(R2, (const uECC_word_t *) P2, (const uECC_word_t *) fe2) != UECC_SUCCESS) + { + return CHIP_ERROR_INTERNAL; + } + + uECC_vli_modSub(z, R2, R1, curve_p); + XYcZ_add(R1, R1 + NUM_ECC_WORDS, R2, R2 + NUM_ECC_WORDS); + uECC_vli_modInv(z, z, curve_p); + apply_z(R2, R2 + NUM_ECC_WORDS, z); + + memcpy((uECC_word_t *) R, R2, 2 * NUM_ECC_BYTES); + + return CHIP_NO_ERROR; +} + +CHIP_ERROR Spake2p_P256_SHA256_HKDF_HMAC::PointInvert(void * R) +{ + uECC_word_t tmp[NUM_ECC_WORDS] = { 0 }; + + uECC_vli_sub(tmp, curve_p, (uECC_word_t *) R + NUM_ECC_WORDS); + memcpy((uECC_word_t *) R + NUM_ECC_WORDS, tmp, NUM_ECC_BYTES); + + return CHIP_NO_ERROR; +} + +CHIP_ERROR Spake2p_P256_SHA256_HKDF_HMAC::PointCofactorMul(void * R) +{ + return CHIP_NO_ERROR; +} + +CHIP_ERROR Spake2p_P256_SHA256_HKDF_HMAC::ComputeL(uint8_t * Lout, size_t * L_len, const uint8_t * w1in, size_t w1in_len) +{ + CHIP_ERROR error = CHIP_NO_ERROR; + int result = 0; + + result = UECC_SUCCESS; + uECC_word_t tmp[2 * NUM_ECC_WORDS]; + uECC_word_t w1_bn[NUM_ECC_WORDS]; + uECC_word_t L_tmp[2 * NUM_ECC_WORDS]; + + uECC_vli_bytesToNative(tmp, w1in, NUM_ECC_BYTES); + + uECC_vli_mmod(w1_bn, tmp, curve_n); + + result = EccPoint_mult_safer(L_tmp, curve_G, w1_bn); + VerifyOrExit(result == UECC_SUCCESS, error = CHIP_ERROR_INTERNAL); + + // Fully padded raw uncompressed points expected, first byte is always 0x04 i.e uncompressed + Lout[0] = 0x04; + uECC_vli_nativeToBytes(Lout + 1, NUM_ECC_BYTES, L_tmp); + uECC_vli_nativeToBytes(Lout + NUM_ECC_BYTES + 1, NUM_ECC_BYTES, L_tmp + NUM_ECC_WORDS); + +exit: + _log_mbedTLS_error(result); + + return error; +} + +CHIP_ERROR Spake2p_P256_SHA256_HKDF_HMAC::PointIsValid(void * R) +{ + if (uECC_valid_point((const uECC_word_t *) R) != 0) + { + return CHIP_ERROR_INTERNAL; + } + + return CHIP_NO_ERROR; +} + +namespace { + +#if defined(MBEDTLS_X509_CRT_PARSE_C) +bool IsTimeGreaterThanEqual(const mbedtls_x509_time * const timeA, const mbedtls_x509_time * const timeB) +{ + + // checks if two values are different and if yes, then returns first > second. +#define RETURN_STRICTLY_GREATER_IF_DIFFERENT(component) \ + { \ + auto valueA = timeA->CHIP_CRYPTO_PAL_PRIVATE_X509(component); \ + auto valueB = timeB->CHIP_CRYPTO_PAL_PRIVATE_X509(component); \ + \ + if (valueA != valueB) \ + { \ + return valueA > valueB; \ + } \ + } + + RETURN_STRICTLY_GREATER_IF_DIFFERENT(year); + RETURN_STRICTLY_GREATER_IF_DIFFERENT(mon); + RETURN_STRICTLY_GREATER_IF_DIFFERENT(day); + RETURN_STRICTLY_GREATER_IF_DIFFERENT(hour); + RETURN_STRICTLY_GREATER_IF_DIFFERENT(min); + RETURN_STRICTLY_GREATER_IF_DIFFERENT(sec); + + // all above are equal + return true; +} + +CHIP_ERROR IsCertificateValidAtIssuance(const mbedtls_x509_crt * candidateCertificate, const mbedtls_x509_crt * issuerCertificate) +{ + mbedtls_x509_time candidateNotBeforeTime = candidateCertificate->CHIP_CRYPTO_PAL_PRIVATE_X509(valid_from); + mbedtls_x509_time issuerNotBeforeTime = issuerCertificate->CHIP_CRYPTO_PAL_PRIVATE_X509(valid_from); + mbedtls_x509_time issuerNotAfterTime = issuerCertificate->CHIP_CRYPTO_PAL_PRIVATE_X509(valid_to); + + // check if candidateCertificate is issued at or after issuerCertificate's notBefore timestamp + VerifyOrReturnError(IsTimeGreaterThanEqual(&candidateNotBeforeTime, &issuerNotBeforeTime), CHIP_ERROR_CERT_EXPIRED); + + // check if candidateCertificate is issued at or before issuerCertificate's notAfter timestamp + VerifyOrReturnError(IsTimeGreaterThanEqual(&issuerNotAfterTime, &candidateNotBeforeTime), CHIP_ERROR_CERT_EXPIRED); + + return CHIP_NO_ERROR; +} + +int CallbackForCustomValidityCheck(void * data, mbedtls_x509_crt * crt, int depth, uint32_t * flags) +{ + mbedtls_x509_crt * leafCert = reinterpret_cast(data); + mbedtls_x509_crt * issuerCert = crt; + + // Ignore any time validy error performed by the standard mbedTLS code. + *flags &= ~(static_cast(MBEDTLS_X509_BADCERT_EXPIRED | MBEDTLS_X509_BADCERT_FUTURE)); + + // Verify that the leaf certificate has a notBefore time valid within the validity period of the issuerCertificate. + // Note that this callback is invoked for each certificate in the chain. + if (IsCertificateValidAtIssuance(leafCert, issuerCert) != CHIP_NO_ERROR) + { + return MBEDTLS_ERR_X509_INVALID_DATE; + } + + return 0; +} + +constexpr uint8_t sOID_AttributeType_CommonName[] = { 0x55, 0x04, 0x03 }; +constexpr uint8_t sOID_AttributeType_MatterVendorId[] = { 0x2B, 0x06, 0x01, 0x04, 0x01, 0x82, 0xA2, 0x7C, 0x02, 0x01 }; +constexpr uint8_t sOID_AttributeType_MatterProductId[] = { 0x2B, 0x06, 0x01, 0x04, 0x01, 0x82, 0xA2, 0x7C, 0x02, 0x02 }; +constexpr uint8_t sOID_SigAlgo_ECDSAWithSHA256[] = { 0x2A, 0x86, 0x48, 0xCE, 0x3D, 0x04, 0x03, 0x02 }; +constexpr uint8_t sOID_Extension_BasicConstraints[] = { 0x55, 0x1D, 0x13 }; +constexpr uint8_t sOID_Extension_KeyUsage[] = { 0x55, 0x1D, 0x0F }; +constexpr uint8_t sOID_Extension_SubjectKeyIdentifier[] = { 0x55, 0x1D, 0x0E }; +constexpr uint8_t sOID_Extension_AuthorityKeyIdentifier[] = { 0x55, 0x1D, 0x23 }; + +/** + * Compares an mbedtls_asn1_buf structure (oidBuf) to a reference OID represented as uint8_t array (oid). + */ +#define OID_CMP(oid, oidBuf) \ + ((MBEDTLS_ASN1_OID == (oidBuf).CHIP_CRYPTO_PAL_PRIVATE_X509(tag)) && \ + (sizeof(oid) == (oidBuf).CHIP_CRYPTO_PAL_PRIVATE_X509(len)) && \ + (memcmp((oid), (oidBuf).CHIP_CRYPTO_PAL_PRIVATE_X509(p), (oidBuf).CHIP_CRYPTO_PAL_PRIVATE_X509(len)) == 0)) + +#endif // defined(MBEDTLS_X509_CRT_PARSE_C) + +} // anonymous namespace + +CHIP_ERROR VerifyAttestationCertificateFormat(const ByteSpan & cert, AttestationCertType certType) +{ +#if defined(MBEDTLS_X509_CRT_PARSE_C) + CHIP_ERROR error = CHIP_NO_ERROR; + int result = 0; + mbedtls_x509_crt mbed_cert; + unsigned char * p = nullptr; + const unsigned char * end = nullptr; + size_t len = 0; + bool extBasicPresent = false; + bool extKeyUsagePresent = false; + + VerifyOrReturnError(!cert.empty(), CHIP_ERROR_INVALID_ARGUMENT); + + mbedtls_x509_crt_init(&mbed_cert); + + result = mbedtls_x509_crt_parse(&mbed_cert, Uint8::to_const_uchar(cert.data()), cert.size()); + VerifyOrExit(result == 0, error = CHIP_ERROR_INTERNAL); + + // "version" value is 1 higher than the actual encoded value. + VerifyOrExit(mbed_cert.CHIP_CRYPTO_PAL_PRIVATE_X509(version) - 1 == 2, error = CHIP_ERROR_INTERNAL); + + // Verify signature algorithms is ECDSA with SHA256. + VerifyOrExit(OID_CMP(sOID_SigAlgo_ECDSAWithSHA256, mbed_cert.CHIP_CRYPTO_PAL_PRIVATE_X509(sig_oid)), + error = CHIP_ERROR_INTERNAL); + + // Verify public key presence and format. + { + Crypto::P256PublicKey pubkey; + SuccessOrExit(error = ExtractPubkeyFromX509Cert(cert, pubkey)); + } + + p = mbed_cert.CHIP_CRYPTO_PAL_PRIVATE_X509(v3_ext).CHIP_CRYPTO_PAL_PRIVATE_X509(p); + end = p + mbed_cert.CHIP_CRYPTO_PAL_PRIVATE_X509(v3_ext).CHIP_CRYPTO_PAL_PRIVATE_X509(len); + result = mbedtls_asn1_get_tag(&p, end, &len, MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE); + VerifyOrExit(result == 0, error = CHIP_ERROR_INTERNAL); + + while (p < end) + { + mbedtls_x509_buf extOID = { 0, 0, nullptr }; + int extCritical = 0; + + result = mbedtls_asn1_get_tag(&p, end, &len, MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE); + VerifyOrExit(result == 0, error = CHIP_ERROR_INTERNAL); + + /* Get extension ID */ + result = mbedtls_asn1_get_tag(&p, end, &len, MBEDTLS_ASN1_OID); + VerifyOrExit(result == 0, error = CHIP_ERROR_INTERNAL); + + extOID.CHIP_CRYPTO_PAL_PRIVATE_X509(tag) = MBEDTLS_ASN1_OID; + extOID.CHIP_CRYPTO_PAL_PRIVATE_X509(len) = len; + extOID.CHIP_CRYPTO_PAL_PRIVATE_X509(p) = p; + p += len; + + /* Get optional critical */ + result = mbedtls_asn1_get_bool(&p, end, &extCritical); + VerifyOrExit(result == 0 || result == MBEDTLS_ERR_ASN1_UNEXPECTED_TAG, error = CHIP_ERROR_INTERNAL); + + /* Data should be octet string type */ + result = mbedtls_asn1_get_tag(&p, end, &len, MBEDTLS_ASN1_OCTET_STRING); + VerifyOrExit(result == 0, error = CHIP_ERROR_INTERNAL); + + if (OID_CMP(sOID_Extension_BasicConstraints, extOID)) + { + int isCA = 0; + int pathLen = -1; + unsigned char * seqStart = p; + + VerifyOrExit(extCritical, error = CHIP_ERROR_INTERNAL); + extBasicPresent = true; + + result = mbedtls_asn1_get_tag(&p, end, &len, MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE); + VerifyOrExit(result == 0, error = CHIP_ERROR_INTERNAL); + if (len > 0) + { + result = mbedtls_asn1_get_bool(&p, end, &isCA); + VerifyOrExit(result == 0 || result == MBEDTLS_ERR_ASN1_UNEXPECTED_TAG, error = CHIP_ERROR_INTERNAL); + + if (p != seqStart + len) + { + result = mbedtls_asn1_get_int(&p, end, &pathLen); + VerifyOrExit(result == 0, error = CHIP_ERROR_INTERNAL); + } + } + + if (certType == AttestationCertType::kDAC) + { + VerifyOrExit(!isCA && pathLen == -1, error = CHIP_ERROR_INTERNAL); + } + else if (certType == AttestationCertType::kPAI) + { + VerifyOrExit(isCA && pathLen == 0, error = CHIP_ERROR_INTERNAL); + } + else + { + VerifyOrExit(isCA && (pathLen == -1 || pathLen == 0 || pathLen == 1), error = CHIP_ERROR_INTERNAL); + } + } + else if (OID_CMP(sOID_Extension_KeyUsage, extOID)) + { + mbedtls_x509_bitstring bs = { 0, 0, nullptr }; + unsigned int keyUsage = 0; + + VerifyOrExit(extCritical, error = CHIP_ERROR_INTERNAL); + extKeyUsagePresent = true; + + result = mbedtls_asn1_get_bitstring(&p, p + len, &bs); + VerifyOrExit(result == 0, error = CHIP_ERROR_INTERNAL); + + for (size_t i = 0; i < bs.CHIP_CRYPTO_PAL_PRIVATE_X509(len) && i < sizeof(unsigned int); i++) + { + keyUsage |= static_cast(bs.CHIP_CRYPTO_PAL_PRIVATE_X509(p)[i]) << (8 * i); + } + + if (certType == AttestationCertType::kDAC) + { + // SHALL only have the digitalSignature bit set. + VerifyOrExit(keyUsage == MBEDTLS_X509_KU_DIGITAL_SIGNATURE, error = CHIP_ERROR_INTERNAL); + } + else + { + bool keyCertSignFlag = keyUsage & MBEDTLS_X509_KU_KEY_CERT_SIGN; + bool crlSignFlag = keyUsage & MBEDTLS_X509_KU_CRL_SIGN; + bool otherFlags = + keyUsage & ~(MBEDTLS_X509_KU_CRL_SIGN | MBEDTLS_X509_KU_KEY_CERT_SIGN | MBEDTLS_X509_KU_DIGITAL_SIGNATURE); + VerifyOrExit(keyCertSignFlag && crlSignFlag && !otherFlags, error = CHIP_ERROR_INTERNAL); + } + } + else + { + p += len; + } + } + + // Verify basic and key usage extensions are present. + VerifyOrExit(extBasicPresent && extKeyUsagePresent, error = CHIP_ERROR_INTERNAL); + + // Verify that SKID and AKID extensions are present. + { + uint8_t kidBuf[kSubjectKeyIdentifierLength]; + MutableByteSpan kid(kidBuf); + SuccessOrExit(error = ExtractSKIDFromX509Cert(cert, kid)); + if (certType == AttestationCertType::kDAC || certType == AttestationCertType::kPAI) + { + // Mandatory extension for DAC and PAI certs. + SuccessOrExit(error = ExtractAKIDFromX509Cert(cert, kid)); + } + } + +exit: + _log_mbedTLS_error(result); + mbedtls_x509_crt_free(&mbed_cert); + +#else + (void) cert; + (void) certType; + CHIP_ERROR error = CHIP_ERROR_NOT_IMPLEMENTED; +#endif // defined(MBEDTLS_X509_CRT_PARSE_C) + + return error; +} + +CHIP_ERROR ValidateCertificateChain(const uint8_t * rootCertificate, size_t rootCertificateLen, const uint8_t * caCertificate, + size_t caCertificateLen, const uint8_t * leafCertificate, size_t leafCertificateLen, + CertificateChainValidationResult & result) +{ +#if defined(MBEDTLS_X509_CRT_PARSE_C) + CHIP_ERROR error = CHIP_NO_ERROR; + mbedtls_x509_crt certChain; + mbedtls_x509_crt rootCert; + int mbedResult; + uint32_t flags = 0; + + result = CertificateChainValidationResult::kInternalFrameworkError; + + VerifyOrReturnError(rootCertificate != nullptr && rootCertificateLen != 0, + (result = CertificateChainValidationResult::kRootArgumentInvalid, CHIP_ERROR_INVALID_ARGUMENT)); + VerifyOrReturnError(leafCertificate != nullptr && leafCertificateLen != 0, + (result = CertificateChainValidationResult::kLeafArgumentInvalid, CHIP_ERROR_INVALID_ARGUMENT)); + + mbedtls_x509_crt_init(&certChain); + mbedtls_x509_crt_init(&rootCert); + + /* Start of chain */ + mbedResult = mbedtls_x509_crt_parse(&certChain, Uint8::to_const_uchar(leafCertificate), leafCertificateLen); + VerifyOrExit(mbedResult == 0, (result = CertificateChainValidationResult::kLeafFormatInvalid, error = CHIP_ERROR_INTERNAL)); + + /* Add the intermediate to the chain, if present */ + if (caCertificate != nullptr && caCertificateLen > 0) + { + mbedResult = mbedtls_x509_crt_parse(&certChain, Uint8::to_const_uchar(caCertificate), caCertificateLen); + VerifyOrExit(mbedResult == 0, (result = CertificateChainValidationResult::kICAFormatInvalid, error = CHIP_ERROR_INTERNAL)); + } + + /* Parse the root cert */ + mbedResult = mbedtls_x509_crt_parse(&rootCert, Uint8::to_const_uchar(rootCertificate), rootCertificateLen); + VerifyOrExit(mbedResult == 0, (result = CertificateChainValidationResult::kRootFormatInvalid, error = CHIP_ERROR_INTERNAL)); + + /* Verify the chain against the root */ + mbedResult = + mbedtls_x509_crt_verify(&certChain, &rootCert, nullptr, nullptr, &flags, CallbackForCustomValidityCheck, &certChain); + + switch (mbedResult) + { + case 0: + VerifyOrExit(flags == 0, (result = CertificateChainValidationResult::kInternalFrameworkError, error = CHIP_ERROR_INTERNAL)); + result = CertificateChainValidationResult::kSuccess; + break; + case MBEDTLS_ERR_X509_INVALID_DATE: + case MBEDTLS_ERR_X509_CERT_VERIFY_FAILED: + result = CertificateChainValidationResult::kChainInvalid; + error = CHIP_ERROR_CERT_NOT_TRUSTED; + break; + default: + SuccessOrExit((result = CertificateChainValidationResult::kInternalFrameworkError, error = CHIP_ERROR_INTERNAL)); + } + +exit: + _log_mbedTLS_error(mbedResult); + mbedtls_x509_crt_free(&certChain); + mbedtls_x509_crt_free(&rootCert); + +#else + (void) rootCertificate; + (void) rootCertificateLen; + (void) caCertificate; + (void) caCertificateLen; + (void) leafCertificate; + (void) leafCertificateLen; + (void) result; + CHIP_ERROR error = CHIP_ERROR_NOT_IMPLEMENTED; +#endif // defined(MBEDTLS_X509_CRT_PARSE_C) + + return error; +} + +CHIP_ERROR IsCertificateValidAtIssuance(const ByteSpan & candidateCertificate, const ByteSpan & issuerCertificate) +{ +#if defined(MBEDTLS_X509_CRT_PARSE_C) + CHIP_ERROR error = CHIP_NO_ERROR; + mbedtls_x509_crt mbedCandidateCertificate; + mbedtls_x509_crt mbedIssuerCertificate; + int result; + + VerifyOrReturnError(!candidateCertificate.empty() && !issuerCertificate.empty(), CHIP_ERROR_INVALID_ARGUMENT); + + mbedtls_x509_crt_init(&mbedCandidateCertificate); + mbedtls_x509_crt_init(&mbedIssuerCertificate); + + result = mbedtls_x509_crt_parse(&mbedCandidateCertificate, Uint8::to_const_uchar(candidateCertificate.data()), + candidateCertificate.size()); + VerifyOrExit(result == 0, error = CHIP_ERROR_INTERNAL); + + result = + mbedtls_x509_crt_parse(&mbedIssuerCertificate, Uint8::to_const_uchar(issuerCertificate.data()), issuerCertificate.size()); + VerifyOrExit(result == 0, error = CHIP_ERROR_INTERNAL); + + // Verify that the candidateCertificate has a notBefore time valid within the validity period of the issuerCertificate. + SuccessOrExit(error = IsCertificateValidAtIssuance(&mbedCandidateCertificate, &mbedIssuerCertificate)); + +exit: + _log_mbedTLS_error(result); + mbedtls_x509_crt_free(&mbedCandidateCertificate); + mbedtls_x509_crt_free(&mbedIssuerCertificate); + +#else + (void) candidateCertificate; + (void) issuerCertificate; + CHIP_ERROR error = CHIP_ERROR_NOT_IMPLEMENTED; +#endif // defined(MBEDTLS_X509_CRT_PARSE_C) + + return error; +} + +CHIP_ERROR IsCertificateValidAtCurrentTime(const ByteSpan & certificate) +{ +#if defined(MBEDTLS_X509_CRT_PARSE_C) + CHIP_ERROR error = CHIP_NO_ERROR; + mbedtls_x509_crt mbedCertificate; + int result; + + VerifyOrReturnError(!certificate.empty(), CHIP_ERROR_INVALID_ARGUMENT); + + mbedtls_x509_crt_init(&mbedCertificate); + + result = mbedtls_x509_crt_parse(&mbedCertificate, Uint8::to_const_uchar(certificate.data()), certificate.size()); + VerifyOrExit(result == 0, error = CHIP_ERROR_INTERNAL); + + // check if certificate's notBefore timestamp is earlier than or equal to current time. + result = mbedtls_x509_time_is_past(&mbedCertificate.CHIP_CRYPTO_PAL_PRIVATE_X509(valid_from)); + VerifyOrExit(result == 1, error = CHIP_ERROR_CERT_EXPIRED); + + // check if certificate's notAfter timestamp is later than current time. + result = mbedtls_x509_time_is_future(&mbedCertificate.CHIP_CRYPTO_PAL_PRIVATE_X509(valid_to)); + VerifyOrExit(result == 1, error = CHIP_ERROR_CERT_EXPIRED); + +exit: + _log_mbedTLS_error(result); + mbedtls_x509_crt_free(&mbedCertificate); + +#else + (void) certificate; + CHIP_ERROR error = CHIP_ERROR_NOT_IMPLEMENTED; +#endif // defined(MBEDTLS_X509_CRT_PARSE_C) + + return error; +} + +CHIP_ERROR ExtractPubkeyFromX509Cert(const ByteSpan & certificate, Crypto::P256PublicKey & pubkey) +{ +#if defined(MBEDTLS_X509_CRT_PARSE_C) + CHIP_ERROR error = CHIP_NO_ERROR; + mbedtls_x509_crt mbed_cert; + mbedtls_uecc_keypair * keypair = nullptr; + size_t pubkey_size = 0; + + mbedtls_x509_crt_init(&mbed_cert); + + int result = mbedtls_x509_crt_parse(&mbed_cert, Uint8::to_const_uchar(certificate.data()), certificate.size()); + VerifyOrExit(result == 0, error = CHIP_ERROR_INTERNAL); + + VerifyOrExit(mbedtls_pk_get_type(&(mbed_cert.CHIP_CRYPTO_PAL_PRIVATE_X509(pk))) == MBEDTLS_PK_ECKEY, + error = CHIP_ERROR_INVALID_ARGUMENT); + + keypair = mbedtls_pk_uecc(mbed_cert.CHIP_CRYPTO_PAL_PRIVATE_X509(pk)); + Uint8::to_uchar(pubkey)[0] = 0x04; // uncompressed type + memcpy(Uint8::to_uchar(pubkey) + 1, keypair->public_key, 2 * NUM_ECC_BYTES); + + VerifyOrExit(result == 0, error = CHIP_ERROR_INTERNAL); + +exit: + _log_mbedTLS_error(result); + mbedtls_x509_crt_free(&mbed_cert); + +#else + (void) certificate; + (void) pubkey; + CHIP_ERROR error = CHIP_ERROR_NOT_IMPLEMENTED; +#endif // defined(MBEDTLS_X509_CRT_PARSE_C) + + return error; +} + +namespace { + +CHIP_ERROR ExtractKIDFromX509Cert(bool extractSKID, const ByteSpan & certificate, MutableByteSpan & kid) +{ +#if defined(MBEDTLS_X509_CRT_PARSE_C) + CHIP_ERROR error = CHIP_ERROR_NOT_FOUND; + mbedtls_x509_crt mbed_cert; + unsigned char * p = nullptr; + const unsigned char * end = nullptr; + size_t len = 0; + + mbedtls_x509_crt_init(&mbed_cert); + + int result = mbedtls_x509_crt_parse(&mbed_cert, Uint8::to_const_uchar(certificate.data()), certificate.size()); + VerifyOrExit(result == 0, error = CHIP_ERROR_INTERNAL); + + // TODO: The mbedTLS team is working on supporting SKID and AKID extensions processing. + // Once it is supported, this code should be updated. + + p = mbed_cert.CHIP_CRYPTO_PAL_PRIVATE_X509(v3_ext).CHIP_CRYPTO_PAL_PRIVATE_X509(p); + end = mbed_cert.CHIP_CRYPTO_PAL_PRIVATE_X509(v3_ext).CHIP_CRYPTO_PAL_PRIVATE_X509(p) + + mbed_cert.CHIP_CRYPTO_PAL_PRIVATE_X509(v3_ext).CHIP_CRYPTO_PAL_PRIVATE_X509(len); + result = mbedtls_asn1_get_tag(&p, end, &len, MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE); + VerifyOrExit(result == 0, error = CHIP_ERROR_WRONG_CERT_TYPE); + + while (p < end) + { + result = mbedtls_asn1_get_tag(&p, end, &len, MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE); + VerifyOrExit(result == 0, error = CHIP_ERROR_WRONG_CERT_TYPE); + result = mbedtls_asn1_get_tag(&p, end, &len, MBEDTLS_ASN1_OID); + VerifyOrExit(result == 0, error = CHIP_ERROR_WRONG_CERT_TYPE); + + mbedtls_x509_buf extOID = { MBEDTLS_ASN1_OID, len, p }; + bool extractCurrentExtSKID = extractSKID && OID_CMP(sOID_Extension_SubjectKeyIdentifier, extOID); + bool extractCurrentExtAKID = !extractSKID && OID_CMP(sOID_Extension_AuthorityKeyIdentifier, extOID); + p += len; + + int is_critical = 0; + result = mbedtls_asn1_get_bool(&p, end, &is_critical); + VerifyOrExit(result == 0 || result == MBEDTLS_ERR_ASN1_UNEXPECTED_TAG, error = CHIP_ERROR_WRONG_CERT_TYPE); + + result = mbedtls_asn1_get_tag(&p, end, &len, MBEDTLS_ASN1_OCTET_STRING); + VerifyOrExit(result == 0, error = CHIP_ERROR_WRONG_CERT_TYPE); + + if (extractCurrentExtSKID || extractCurrentExtAKID) + { + if (extractCurrentExtSKID) + { + result = mbedtls_asn1_get_tag(&p, end, &len, MBEDTLS_ASN1_OCTET_STRING); + VerifyOrExit(result == 0, error = CHIP_ERROR_WRONG_CERT_TYPE); + } + else + { + result = mbedtls_asn1_get_tag(&p, end, &len, MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE); + VerifyOrExit(result == 0, error = CHIP_ERROR_WRONG_CERT_TYPE); + result = mbedtls_asn1_get_tag(&p, end, &len, MBEDTLS_ASN1_CONTEXT_SPECIFIC); + VerifyOrExit(result == 0, error = CHIP_ERROR_WRONG_CERT_TYPE); + // Other optional fields, authorityCertIssuer and authorityCertSerialNumber, + // will be skipped if present. + } + VerifyOrExit(len == kSubjectKeyIdentifierLength, error = CHIP_ERROR_WRONG_CERT_TYPE); + VerifyOrExit(len <= kid.size(), error = CHIP_ERROR_BUFFER_TOO_SMALL); + memcpy(kid.data(), p, len); + if (kid.size() > len) + { + kid.reduce_size(len); + } + ExitNow(error = CHIP_NO_ERROR); + break; + } + p += len; + } + +exit: + _log_mbedTLS_error(result); + mbedtls_x509_crt_free(&mbed_cert); + +#else + (void) certificate; + (void) kid; + CHIP_ERROR error = CHIP_ERROR_NOT_IMPLEMENTED; +#endif // defined(MBEDTLS_X509_CRT_PARSE_C) + + return error; +} + +} // namespace + +CHIP_ERROR ExtractSKIDFromX509Cert(const ByteSpan & certificate, MutableByteSpan & skid) +{ + return ExtractKIDFromX509Cert(true, certificate, skid); +} + +CHIP_ERROR ExtractAKIDFromX509Cert(const ByteSpan & certificate, MutableByteSpan & akid) +{ + return ExtractKIDFromX509Cert(false, certificate, akid); +} + +CHIP_ERROR ExtractVIDPIDFromX509Cert(const ByteSpan & certificate, AttestationCertVidPid & vidpid) +{ +#if defined(MBEDTLS_X509_CRT_PARSE_C) + CHIP_ERROR error = CHIP_NO_ERROR; + mbedtls_x509_crt mbed_cert; + mbedtls_asn1_named_data * dnIterator = nullptr; + AttestationCertVidPid vidpidFromCN; + + mbedtls_x509_crt_init(&mbed_cert); + + int result = mbedtls_x509_crt_parse(&mbed_cert, Uint8::to_const_uchar(certificate.data()), certificate.size()); + VerifyOrExit(result == 0, error = CHIP_ERROR_INTERNAL); + + for (dnIterator = &mbed_cert.CHIP_CRYPTO_PAL_PRIVATE_X509(subject); dnIterator != nullptr; + dnIterator = dnIterator->CHIP_CRYPTO_PAL_PRIVATE_X509(next)) + { + DNAttrType attrType = DNAttrType::kUnspecified; + if (OID_CMP(sOID_AttributeType_CommonName, dnIterator->CHIP_CRYPTO_PAL_PRIVATE_X509(oid))) + { + attrType = DNAttrType::kCommonName; + } + else if (OID_CMP(sOID_AttributeType_MatterVendorId, dnIterator->CHIP_CRYPTO_PAL_PRIVATE_X509(oid))) + { + attrType = DNAttrType::kMatterVID; + } + else if (OID_CMP(sOID_AttributeType_MatterProductId, dnIterator->CHIP_CRYPTO_PAL_PRIVATE_X509(oid))) + { + attrType = DNAttrType::kMatterPID; + } + + size_t val_len = dnIterator->CHIP_CRYPTO_PAL_PRIVATE_X509(val).CHIP_CRYPTO_PAL_PRIVATE_X509(len); + uint8_t * val_p = dnIterator->CHIP_CRYPTO_PAL_PRIVATE_X509(val).CHIP_CRYPTO_PAL_PRIVATE_X509(p); + error = ExtractVIDPIDFromAttributeString(attrType, ByteSpan(val_p, val_len), vidpid, vidpidFromCN); + SuccessOrExit(error); + } + + // If Matter Attributes were not found use values extracted from the CN Attribute, + // which might be uninitialized as well. + if (!vidpid.Initialized()) + { + vidpid = vidpidFromCN; + } + +exit: + _log_mbedTLS_error(result); + mbedtls_x509_crt_free(&mbed_cert); + +#else + (void) certificate; + (void) vidpid; + CHIP_ERROR error = CHIP_ERROR_NOT_IMPLEMENTED; +#endif // defined(MBEDTLS_X509_CRT_PARSE_C) + + return error; +} + +namespace { +#if defined(MBEDTLS_X509_CRT_PARSE_C) +CHIP_ERROR ExtractRawSubjectFromX509Cert(const ByteSpan & certificate, MutableByteSpan & subject) +{ + CHIP_ERROR error = CHIP_NO_ERROR; + int result = 0; + uint8_t * p = nullptr; + size_t len = 0; + mbedtls_x509_crt mbedCertificate; + + ReturnErrorCodeIf(certificate.empty(), CHIP_ERROR_INVALID_ARGUMENT); + + mbedtls_x509_crt_init(&mbedCertificate); + result = mbedtls_x509_crt_parse(&mbedCertificate, Uint8::to_const_uchar(certificate.data()), certificate.size()); + VerifyOrExit(result == 0, error = CHIP_ERROR_INTERNAL); + + len = mbedCertificate.CHIP_CRYPTO_PAL_PRIVATE_X509(subject_raw).CHIP_CRYPTO_PAL_PRIVATE_X509(len); + p = mbedCertificate.CHIP_CRYPTO_PAL_PRIVATE_X509(subject_raw).CHIP_CRYPTO_PAL_PRIVATE_X509(p); + + VerifyOrExit(len <= subject.size(), error = CHIP_ERROR_BUFFER_TOO_SMALL); + memcpy(subject.data(), p, len); + subject.reduce_size(len); + +exit: + _log_mbedTLS_error(result); + mbedtls_x509_crt_free(&mbedCertificate); + + return error; +} +#endif // defined(MBEDTLS_X509_CRT_PARSE_C) +} // namespace + +CHIP_ERROR ReplaceCertIfResignedCertFound(const ByteSpan & referenceCertificate, const ByteSpan * candidateCertificates, + size_t candidateCertificatesCount, ByteSpan & outCertificate) +{ +#if defined(MBEDTLS_X509_CRT_PARSE_C) + constexpr size_t kMaxCertificateSubjectLength = 150; + uint8_t referenceSubjectBuf[kMaxCertificateSubjectLength]; + uint8_t referenceSKIDBuf[kSubjectKeyIdentifierLength]; + MutableByteSpan referenceSubject(referenceSubjectBuf); + MutableByteSpan referenceSKID(referenceSKIDBuf); + + outCertificate = referenceCertificate; + + ReturnErrorCodeIf(candidateCertificates == nullptr || candidateCertificatesCount == 0, CHIP_NO_ERROR); + + ReturnErrorOnFailure(ExtractRawSubjectFromX509Cert(referenceCertificate, referenceSubject)); + ReturnErrorOnFailure(ExtractSKIDFromX509Cert(referenceCertificate, referenceSKID)); + + for (size_t i = 0; i < candidateCertificatesCount; i++) + { + const ByteSpan candidateCertificate = candidateCertificates[i]; + uint8_t candidateSubjectBuf[kMaxCertificateSubjectLength]; + uint8_t candidateSKIDBuf[kSubjectKeyIdentifierLength]; + MutableByteSpan candidateSubject(candidateSubjectBuf); + MutableByteSpan candidateSKID(candidateSKIDBuf); + + ReturnErrorOnFailure(ExtractRawSubjectFromX509Cert(candidateCertificate, candidateSubject)); + ReturnErrorOnFailure(ExtractSKIDFromX509Cert(candidateCertificate, candidateSKID)); + + if (referenceSKID.data_equal(candidateSKID) && referenceSubject.data_equal(candidateSubject)) + { + outCertificate = candidateCertificate; + return CHIP_NO_ERROR; + } + } + + return CHIP_NO_ERROR; +#else + (void) referenceCertificate; + (void) candidateCertificates; + (void) candidateCertificatesCount; + (void) outCertificate; + return CHIP_ERROR_NOT_IMPLEMENTED; +#endif // defined(MBEDTLS_X509_CRT_PARSE_C) +} + +} // namespace Crypto +} // namespace chip diff --git a/src/platform/silabs/SiWx917/wifi_args.gni b/src/platform/silabs/SiWx917/wifi_args.gni index 44f07f37985d88..d63fb5e1d89a2c 100644 --- a/src/platform/silabs/SiWx917/wifi_args.gni +++ b/src/platform/silabs/SiWx917/wifi_args.gni @@ -25,7 +25,7 @@ arm_platform_config = "${efr32_sdk_build_root}/efr32_arm.gni" mbedtls_target = "${efr32_sdk_build_root}:efr32_sdk" -chip_crypto = "tinycrypt" +chip_crypto = "platform" # Transitional CommissionableDataProvider not used anymore # examples/platform/efr32/EFR32DeviceDataProvider is now used.