| // Copyright 2014 The Chromium Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| #include <stddef.h> |
| |
| #include "base/numerics/safe_math.h" |
| #include "components/webcrypto/algorithms/rsa_sign.h" |
| #include "components/webcrypto/algorithms/util.h" |
| #include "components/webcrypto/blink_key_handle.h" |
| #include "components/webcrypto/crypto_data.h" |
| #include "components/webcrypto/status.h" |
| #include "crypto/openssl_util.h" |
| #include "third_party/blink/public/platform/web_crypto_key_algorithm.h" |
| #include "third_party/boringssl/src/include/openssl/digest.h" |
| #include "third_party/boringssl/src/include/openssl/evp.h" |
| #include "third_party/boringssl/src/include/openssl/rsa.h" |
| |
| namespace webcrypto { |
| |
| namespace { |
| |
| // Extracts the OpenSSL key and digest from a WebCrypto key. The returned |
| // pointers will remain valid as long as |key| is alive. |
| Status GetPKeyAndDigest(const blink::WebCryptoKey& key, |
| EVP_PKEY** pkey, |
| const EVP_MD** digest) { |
| *pkey = GetEVP_PKEY(key); |
| |
| *digest = GetDigest(key.Algorithm().RsaHashedParams()->GetHash()); |
| if (!*digest) |
| return Status::ErrorUnsupported(); |
| |
| return Status::Success(); |
| } |
| |
| // Sets the PSS parameters on |pctx| if the key is for RSA-PSS. |
| // |
| // Otherwise returns Success without doing anything. |
| Status ApplyRsaPssOptions(const blink::WebCryptoKey& key, |
| const EVP_MD* const mgf_digest, |
| unsigned int salt_length_bytes, |
| EVP_PKEY_CTX* pctx) { |
| // Only apply RSA-PSS options if the key is for RSA-PSS. |
| if (key.Algorithm().Id() != blink::kWebCryptoAlgorithmIdRsaPss) { |
| DCHECK_EQ(0u, salt_length_bytes); |
| DCHECK_EQ(blink::kWebCryptoAlgorithmIdRsaSsaPkcs1v1_5, |
| key.Algorithm().Id()); |
| return Status::Success(); |
| } |
| |
| // BoringSSL takes a signed int for the salt length, and interprets |
| // negative values in a special manner. Make sure not to silently underflow. |
| base::CheckedNumeric<int> salt_length_bytes_int(salt_length_bytes); |
| if (!salt_length_bytes_int.IsValid()) { |
| // TODO(eroman): Give a better error message. |
| return Status::OperationError(); |
| } |
| |
| if (1 != EVP_PKEY_CTX_set_rsa_padding(pctx, RSA_PKCS1_PSS_PADDING) || |
| 1 != EVP_PKEY_CTX_set_rsa_mgf1_md(pctx, mgf_digest) || |
| 1 != EVP_PKEY_CTX_set_rsa_pss_saltlen( |
| pctx, salt_length_bytes_int.ValueOrDie())) { |
| return Status::OperationError(); |
| } |
| |
| return Status::Success(); |
| } |
| |
| } // namespace |
| |
| Status RsaSign(const blink::WebCryptoKey& key, |
| unsigned int pss_salt_length_bytes, |
| const CryptoData& data, |
| std::vector<uint8_t>* buffer) { |
| if (key.GetType() != blink::kWebCryptoKeyTypePrivate) |
| return Status::ErrorUnexpectedKeyType(); |
| |
| crypto::OpenSSLErrStackTracer err_tracer(FROM_HERE); |
| bssl::ScopedEVP_MD_CTX ctx; |
| EVP_PKEY_CTX* pctx = nullptr; // Owned by |ctx|. |
| |
| EVP_PKEY* private_key = nullptr; |
| const EVP_MD* digest = nullptr; |
| Status status = GetPKeyAndDigest(key, &private_key, &digest); |
| if (status.IsError()) |
| return status; |
| |
| // NOTE: A call to EVP_DigestSignFinal() with a NULL second parameter |
| // returns a maximum allocation size, while the call without a NULL returns |
| // the real one, which may be smaller. |
| size_t sig_len = 0; |
| if (!EVP_DigestSignInit(ctx.get(), &pctx, digest, nullptr, private_key)) { |
| return Status::OperationError(); |
| } |
| |
| // Set PSS-specific options (if applicable). |
| status = ApplyRsaPssOptions(key, digest, pss_salt_length_bytes, pctx); |
| if (status.IsError()) |
| return status; |
| |
| if (!EVP_DigestSignUpdate(ctx.get(), data.bytes(), data.byte_length()) || |
| !EVP_DigestSignFinal(ctx.get(), nullptr, &sig_len)) { |
| return Status::OperationError(); |
| } |
| |
| buffer->resize(sig_len); |
| if (!EVP_DigestSignFinal(ctx.get(), buffer->data(), &sig_len)) |
| return Status::OperationError(); |
| |
| buffer->resize(sig_len); |
| return Status::Success(); |
| } |
| |
| Status RsaVerify(const blink::WebCryptoKey& key, |
| unsigned int pss_salt_length_bytes, |
| const CryptoData& signature, |
| const CryptoData& data, |
| bool* signature_match) { |
| if (key.GetType() != blink::kWebCryptoKeyTypePublic) |
| return Status::ErrorUnexpectedKeyType(); |
| |
| crypto::OpenSSLErrStackTracer err_tracer(FROM_HERE); |
| bssl::ScopedEVP_MD_CTX ctx; |
| EVP_PKEY_CTX* pctx = nullptr; // Owned by |ctx|. |
| |
| EVP_PKEY* public_key = nullptr; |
| const EVP_MD* digest = nullptr; |
| Status status = GetPKeyAndDigest(key, &public_key, &digest); |
| if (status.IsError()) |
| return status; |
| |
| if (!EVP_DigestVerifyInit(ctx.get(), &pctx, digest, nullptr, public_key)) |
| return Status::OperationError(); |
| |
| // Set PSS-specific options (if applicable). |
| status = ApplyRsaPssOptions(key, digest, pss_salt_length_bytes, pctx); |
| if (status.IsError()) |
| return status; |
| |
| if (!EVP_DigestVerifyUpdate(ctx.get(), data.bytes(), data.byte_length())) |
| return Status::OperationError(); |
| |
| *signature_match = 1 == EVP_DigestVerifyFinal(ctx.get(), signature.bytes(), |
| signature.byte_length()); |
| return Status::Success(); |
| } |
| |
| } // namespace webcrypto |