| /* |
| * |
| * 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 "CHIPCryptoPAL.h" |
| |
| #include <type_traits> |
| |
| #include <mbedtls/bignum.h> |
| #include <mbedtls/ccm.h> |
| #include <mbedtls/ctr_drbg.h> |
| #include <mbedtls/ecdh.h> |
| #include <mbedtls/ecdsa.h> |
| #include <mbedtls/ecp.h> |
| #include <mbedtls/entropy.h> |
| #include <mbedtls/error.h> |
| #include <mbedtls/hkdf.h> |
| #include <mbedtls/md.h> |
| #include <mbedtls/pkcs5.h> |
| #include <mbedtls/sha1.h> |
| #include <mbedtls/sha256.h> |
| #if defined(MBEDTLS_X509_CRT_PARSE_C) |
| #include <mbedtls/x509_crt.h> |
| #endif // defined(MBEDTLS_X509_CRT_PARSE_C) |
| #include <mbedtls/oid.h> |
| #include <mbedtls/x509.h> |
| #include <mbedtls/x509_csr.h> |
| |
| #include <lib/core/CHIPSafeCasts.h> |
| #include <lib/support/BufferWriter.h> |
| #include <lib/support/BytesToHex.h> |
| #include <lib/support/CHIPArgParser.hpp> |
| #include <lib/support/CodeUtils.h> |
| #include <lib/support/SafeInt.h> |
| #include <lib/support/SafePointerCast.h> |
| #include <lib/support/logging/CHIPLogging.h> |
| |
| #include <string.h> |
| |
| 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) |
| { |
| #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<uint16_t>(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); |
| } |
| |
| // Size of key is expressed in bits, hence the multiplication by 8. |
| result = mbedtls_ccm_setkey(&context, MBEDTLS_CIPHER_ID_AES, key.As<Symmetric128BitsKeyByteArray>(), |
| sizeof(Symmetric128BitsKeyByteArray) * 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); |
| } |
| |
| // Size of key is expressed in bits, hence the multiplication by 8. |
| result = mbedtls_ccm_setkey(&context, MBEDTLS_CIPHER_ID_AES, key.As<Symmetric128BitsKeyByteArray>(), |
| sizeof(Symmetric128BitsKeyByteArray) * 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<mbedtls_sha256_context *>(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)); |
| } |
| |
| static EntropyContext * get_entropy_context() |
| { |
| if (!gsEntropyContext.mInitialized) |
| { |
| mbedtls_entropy_init(&gsEntropyContext.mEntropy); |
| mbedtls_ctr_drbg_init(&gsEntropyContext.mDRBGCtxt); |
| |
| gsEntropyContext.mInitialized = true; |
| } |
| |
| return &gsEntropyContext; |
| } |
| |
| 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; |
| } |
| |
| 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_ecp_keypair * to_keypair(P256KeypairContext * context) |
| { |
| return SafePointerCast<mbedtls_ecp_keypair *>(context); |
| } |
| |
| static inline const mbedtls_ecp_keypair * to_const_keypair(const P256KeypairContext * context) |
| { |
| return SafePointerCast<const mbedtls_ecp_keypair *>(context); |
| } |
| |
| // 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; |
| } |
| |
| void P256Keypair::Clear() |
| { |
| if (mInitialized) |
| { |
| mbedtls_ecp_keypair * keypair = to_keypair(&mKeypair); |
| mbedtls_ecp_keypair_free(keypair); |
| mInitialized = false; |
| } |
| } |
| |
| 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 |
| { |
| mbedtls_ecp_group curve; |
| mbedtls_ecp_point M; |
| mbedtls_ecp_point N; |
| mbedtls_ecp_point X; |
| mbedtls_ecp_point Y; |
| mbedtls_ecp_point L; |
| mbedtls_ecp_point Z; |
| mbedtls_ecp_point V; |
| |
| mbedtls_mpi w0; |
| mbedtls_mpi w1; |
| mbedtls_mpi xy; |
| mbedtls_mpi tempbn; |
| } Spake2p_Context; |
| |
| static inline Spake2p_Context * to_inner_spake2p_context(Spake2pOpaqueContext * context) |
| { |
| return SafePointerCast<Spake2p_Context *>(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)); |
| |
| mbedtls_ecp_group_init(&context->curve); |
| result = mbedtls_ecp_group_load(&context->curve, MBEDTLS_ECP_DP_SECP256R1); |
| VerifyOrExit(result == 0, error = CHIP_ERROR_INTERNAL); |
| |
| VerifyOrExit(mbedtls_md_info_from_type(MBEDTLS_MD_SHA256) != nullptr, error = CHIP_ERROR_INTERNAL); |
| |
| mbedtls_ecp_point_init(&context->M); |
| mbedtls_ecp_point_init(&context->N); |
| mbedtls_ecp_point_init(&context->X); |
| mbedtls_ecp_point_init(&context->Y); |
| mbedtls_ecp_point_init(&context->L); |
| mbedtls_ecp_point_init(&context->V); |
| mbedtls_ecp_point_init(&context->Z); |
| M = &context->M; |
| N = &context->N; |
| X = &context->X; |
| Y = &context->Y; |
| L = &context->L; |
| V = &context->V; |
| Z = &context->Z; |
| |
| mbedtls_mpi_init(&context->w0); |
| mbedtls_mpi_init(&context->w1); |
| mbedtls_mpi_init(&context->xy); |
| mbedtls_mpi_init(&context->tempbn); |
| w0 = &context->w0; |
| w1 = &context->w1; |
| xy = &context->xy; |
| tempbn = &context->tempbn; |
| |
| G = &context->curve.G; |
| order = &context->curve.N; |
| |
| 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); |
| mbedtls_ecp_point_free(&context->M); |
| mbedtls_ecp_point_free(&context->N); |
| mbedtls_ecp_point_free(&context->X); |
| mbedtls_ecp_point_free(&context->Y); |
| mbedtls_ecp_point_free(&context->L); |
| mbedtls_ecp_point_free(&context->Z); |
| mbedtls_ecp_point_free(&context->V); |
| |
| mbedtls_mpi_free(&context->w0); |
| mbedtls_mpi_free(&context->w1); |
| mbedtls_mpi_free(&context->xy); |
| mbedtls_mpi_free(&context->tempbn); |
| |
| mbedtls_ecp_group_free(&context->curve); |
| 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; |
| |
| result = mbedtls_mpi_read_binary((mbedtls_mpi *) fe, Uint8::to_const_uchar(in), in_len); |
| VerifyOrExit(result == 0, error = CHIP_ERROR_INTERNAL); |
| |
| result = mbedtls_mpi_mod_mpi((mbedtls_mpi *) fe, (mbedtls_mpi *) fe, (const mbedtls_mpi *) order); |
| VerifyOrExit(result == 0, error = CHIP_ERROR_INTERNAL); |
| |
| 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) |
| { |
| if (mbedtls_mpi_write_binary((const mbedtls_mpi *) fe, Uint8::to_uchar(out), out_len) != 0) |
| { |
| return CHIP_ERROR_INTERNAL; |
| } |
| return CHIP_NO_ERROR; |
| } |
| |
| CHIP_ERROR Spake2p_P256_SHA256_HKDF_HMAC::FEGenerate(void * fe) |
| { |
| CHIP_ERROR error = CHIP_NO_ERROR; |
| int result = 0; |
| |
| Spake2p_Context * context = to_inner_spake2p_context(&mSpake2pContext); |
| |
| result = mbedtls_ecp_gen_privkey(&context->curve, (mbedtls_mpi *) fe, CryptoRNG, nullptr); |
| VerifyOrExit(result == 0, error = CHIP_ERROR_INTERNAL); |
| |
| 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; |
| |
| result = mbedtls_mpi_mul_mpi((mbedtls_mpi *) fer, (const mbedtls_mpi *) fe1, (const mbedtls_mpi *) fe2); |
| VerifyOrExit(result == 0, error = CHIP_ERROR_INTERNAL); |
| |
| result = mbedtls_mpi_mod_mpi((mbedtls_mpi *) fer, (mbedtls_mpi *) fer, (const mbedtls_mpi *) order); |
| VerifyOrExit(result == 0, error = CHIP_ERROR_INTERNAL); |
| |
| 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) |
| { |
| Spake2p_Context * context = to_inner_spake2p_context(&mSpake2pContext); |
| |
| if (mbedtls_ecp_point_read_binary(&context->curve, (mbedtls_ecp_point *) R, Uint8::to_const_uchar(in), in_len) != 0) |
| { |
| return CHIP_ERROR_INTERNAL; |
| } |
| |
| 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); |
| |
| size_t mbedtls_out_len = out_len; |
| |
| Spake2p_Context * context = to_inner_spake2p_context(&mSpake2pContext); |
| |
| if (mbedtls_ecp_point_write_binary(&context->curve, (const mbedtls_ecp_point *) R, MBEDTLS_ECP_PF_UNCOMPRESSED, |
| &mbedtls_out_len, Uint8::to_uchar(out), out_len) != 0) |
| { |
| return CHIP_ERROR_INTERNAL; |
| } |
| |
| return CHIP_NO_ERROR; |
| } |
| |
| CHIP_ERROR Spake2p_P256_SHA256_HKDF_HMAC::PointMul(void * R, const void * P1, const void * fe1) |
| { |
| Spake2p_Context * context = to_inner_spake2p_context(&mSpake2pContext); |
| |
| if (mbedtls_ecp_mul(&context->curve, (mbedtls_ecp_point *) R, (const mbedtls_mpi *) fe1, (const mbedtls_ecp_point *) P1, |
| CryptoRNG, nullptr) != 0) |
| { |
| 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) |
| { |
| Spake2p_Context * context = to_inner_spake2p_context(&mSpake2pContext); |
| |
| if (mbedtls_ecp_muladd(&context->curve, (mbedtls_ecp_point *) R, (const mbedtls_mpi *) fe1, (const mbedtls_ecp_point *) P1, |
| (const mbedtls_mpi *) fe2, (const mbedtls_ecp_point *) P2) != 0) |
| { |
| return CHIP_ERROR_INTERNAL; |
| } |
| |
| return CHIP_NO_ERROR; |
| } |
| |
| CHIP_ERROR Spake2p_P256_SHA256_HKDF_HMAC::PointInvert(void * R) |
| { |
| mbedtls_ecp_point * Rp = (mbedtls_ecp_point *) R; |
| Spake2p_Context * context = to_inner_spake2p_context(&mSpake2pContext); |
| |
| if (mbedtls_mpi_sub_mpi(&Rp->CHIP_CRYPTO_PAL_PRIVATE(Y), &context->curve.P, &Rp->CHIP_CRYPTO_PAL_PRIVATE(Y)) != 0) |
| { |
| return CHIP_ERROR_INTERNAL; |
| } |
| |
| 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; |
| |
| mbedtls_ecp_group curve; |
| mbedtls_mpi w1_bn; |
| mbedtls_ecp_point Ltemp; |
| |
| mbedtls_ecp_group_init(&curve); |
| mbedtls_mpi_init(&w1_bn); |
| mbedtls_ecp_point_init(&Ltemp); |
| |
| result = mbedtls_ecp_group_load(&curve, MBEDTLS_ECP_DP_SECP256R1); |
| VerifyOrExit(result == 0, error = CHIP_ERROR_INTERNAL); |
| |
| result = mbedtls_mpi_read_binary(&w1_bn, Uint8::to_const_uchar(w1in), w1in_len); |
| VerifyOrExit(result == 0, error = CHIP_ERROR_INTERNAL); |
| |
| result = mbedtls_mpi_mod_mpi(&w1_bn, &w1_bn, &curve.N); |
| VerifyOrExit(result == 0, error = CHIP_ERROR_INTERNAL); |
| |
| result = mbedtls_ecp_mul(&curve, &Ltemp, &w1_bn, &curve.G, CryptoRNG, nullptr); |
| VerifyOrExit(result == 0, error = CHIP_ERROR_INTERNAL); |
| |
| memset(Lout, 0, *L_len); |
| |
| result = mbedtls_ecp_point_write_binary(&curve, &Ltemp, MBEDTLS_ECP_PF_UNCOMPRESSED, L_len, Uint8::to_uchar(Lout), *L_len); |
| VerifyOrExit(result == 0, error = CHIP_ERROR_INTERNAL); |
| |
| exit: |
| _log_mbedTLS_error(result); |
| mbedtls_ecp_point_free(&Ltemp); |
| mbedtls_mpi_free(&w1_bn); |
| mbedtls_ecp_group_free(&curve); |
| |
| return error; |
| } |
| |
| CHIP_ERROR Spake2p_P256_SHA256_HKDF_HMAC::PointIsValid(void * R) |
| { |
| Spake2p_Context * context = to_inner_spake2p_context(&mSpake2pContext); |
| |
| if (mbedtls_ecp_check_pubkey(&context->curve, (mbedtls_ecp_point *) 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<mbedtls_x509_crt *>(data); |
| mbedtls_x509_crt * issuerCert = crt; |
| |
| // Ignore any time validy error performed by the standard mbedTLS code. |
| *flags &= ~(static_cast<uint32_t>(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<unsigned int>(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: |
| result = CertificateChainValidationResult::kInternalFrameworkError; |
| error = CHIP_ERROR_INTERNAL; |
| break; |
| } |
| |
| 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_ecp_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_ec(mbed_cert.CHIP_CRYPTO_PAL_PRIVATE_X509(pk)); |
| VerifyOrExit(keypair->CHIP_CRYPTO_PAL_PRIVATE(grp).id == MapECPGroupId(pubkey.Type()), error = CHIP_ERROR_INVALID_ARGUMENT); |
| // Copy the public key from the cert in raw point format |
| 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.Bytes()), pubkey.Length()); |
| |
| VerifyOrExit(result == 0, error = CHIP_ERROR_INTERNAL); |
| VerifyOrExit(pubkey_size == pubkey.Length(), 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 Crypto |
| } // namespace chip |