content/child/webcrypto/openssl/rsa_ssa_openssl.cc

   1 // Copyright 2014 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "content/child/webcrypto/crypto_data.h"
   6 #include "content/child/webcrypto/openssl/key_openssl.h"
   7 #include "content/child/webcrypto/openssl/rsa_key_openssl.h"
   8 #include "content/child/webcrypto/openssl/util_openssl.h"
   9 #include "content/child/webcrypto/status.h"
  10 #include "crypto/openssl_util.h"
  11 #include "crypto/scoped_openssl_types.h"
  12 #include "third_party/WebKit/public/platform/WebCryptoKeyAlgorithm.h"
  13
  14 namespace content {
  15
  16 namespace webcrypto {
  17
  18 namespace {
  19
  20 // Extracts the OpenSSL key and digest from a WebCrypto key. The returned
  21 // pointers will remain valid as long as |key| is alive.
  22 Status GetPKeyAndDigest(const blink::WebCryptoKey& key,
  23                         EVP_PKEY** pkey,
  24                         const EVP_MD** digest) {
  25   *pkey = AsymKeyOpenSsl::Cast(key)->key();
  26
  27   *digest = GetDigest(key.algorithm().rsaHashedParams()->hash().id());
  28   if (!*digest)
  29     return Status::ErrorUnsupported();
  30
  31   return Status::Success();
  32 }
  33
  34 class RsaSsaImplementation : public RsaHashedAlgorithm {
  35  public:
  36   RsaSsaImplementation()
  37       : RsaHashedAlgorithm(blink::WebCryptoKeyUsageVerify,
  38                            blink::WebCryptoKeyUsageSign) {}
  39
  40   virtual const char* GetJwkAlgorithm(
  41       const blink::WebCryptoAlgorithmId hash) const OVERRIDE {
  42     switch (hash) {
  43       case blink::WebCryptoAlgorithmIdSha1:
  44         return "RS1";
  45       case blink::WebCryptoAlgorithmIdSha256:
  46         return "RS256";
  47       case blink::WebCryptoAlgorithmIdSha384:
  48         return "RS384";
  49       case blink::WebCryptoAlgorithmIdSha512:
  50         return "RS512";
  51       default:
  52         return NULL;
  53     }
  54   }
  55
  56   virtual Status Sign(const blink::WebCryptoAlgorithm& algorithm,
  57                       const blink::WebCryptoKey& key,
  58                       const CryptoData& data,
  59                       std::vector<uint8_t>* buffer) const OVERRIDE {
  60     if (key.type() != blink::WebCryptoKeyTypePrivate)
  61       return Status::ErrorUnexpectedKeyType();
  62
  63     crypto::OpenSSLErrStackTracer err_tracer(FROM_HERE);
  64     crypto::ScopedEVP_MD_CTX ctx(EVP_MD_CTX_create());
  65
  66     EVP_PKEY* private_key = NULL;
  67     const EVP_MD* digest = NULL;
  68     Status status = GetPKeyAndDigest(key, &private_key, &digest);
  69     if (status.IsError())
  70       return status;
  71
  72     // NOTE: A call to EVP_DigestSignFinal() with a NULL second parameter
  73     // returns a maximum allocation size, while the call without a NULL returns
  74     // the real one, which may be smaller.
  75     size_t sig_len = 0;
  76     if (!ctx.get() ||
  77         !EVP_DigestSignInit(ctx.get(), NULL, digest, NULL, private_key) ||
  78         !EVP_DigestSignUpdate(ctx.get(), data.bytes(), data.byte_length()) ||
  79         !EVP_DigestSignFinal(ctx.get(), NULL, &sig_len)) {
  80       return Status::OperationError();
  81     }
  82
  83     buffer->resize(sig_len);
  84     if (!EVP_DigestSignFinal(ctx.get(), &buffer->front(), &sig_len))
  85       return Status::OperationError();
  86
  87     buffer->resize(sig_len);
  88     return Status::Success();
  89   }
  90
  91   virtual Status Verify(const blink::WebCryptoAlgorithm& algorithm,
  92                         const blink::WebCryptoKey& key,
  93                         const CryptoData& signature,
  94                         const CryptoData& data,
  95                         bool* signature_match) const OVERRIDE {
  96     if (key.type() != blink::WebCryptoKeyTypePublic)
  97       return Status::ErrorUnexpectedKeyType();
  98
  99     crypto::OpenSSLErrStackTracer err_tracer(FROM_HERE);
 100     crypto::ScopedEVP_MD_CTX ctx(EVP_MD_CTX_create());
 101
 102     EVP_PKEY* public_key = NULL;
 103     const EVP_MD* digest = NULL;
 104     Status status = GetPKeyAndDigest(key, &public_key, &digest);
 105     if (status.IsError())
 106       return status;
 107
 108     if (!EVP_DigestVerifyInit(ctx.get(), NULL, digest, NULL, public_key))
 109       return Status::OperationError();
 110
 111     if (!EVP_DigestVerifyUpdate(ctx.get(), data.bytes(), data.byte_length())) {
 112       return Status::OperationError();
 113     }
 114
 115     // Note that the return value can be:
 116     //   1 --> Success
 117     //   0 --> Verification failed
 118     //  <0 --> Operation error
 119     int rv = EVP_DigestVerifyFinal(
 120         ctx.get(), signature.bytes(), signature.byte_length());
 121     *signature_match = rv == 1;
 122     return rv >= 0 ? Status::Success() : Status::OperationError();
 123   }
 124 };
 125
 126 }  // namespace
 127
 128 AlgorithmImplementation* CreatePlatformRsaSsaImplementation() {
 129   return new RsaSsaImplementation;
 130 }
 131
 132 }  // namespace webcrypto
 133
 134 }  // namespace content