Implements Signature Creator & Verifier for openssl

base/crypto/signature_verifier_openssl.cc

 // Copyright (c) 2010 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 "base/crypto/signature_verifier.h"
 
+#include <openssl/evp.h>
+#include <openssl/x509.h>
+
+#include <vector>
+
 #include "base/logging.h"
+#include "base/openssl_util.h"
+#include "base/scoped_ptr.h"
 
 namespace base {
 
-SignatureVerifier::SignatureVerifier() {
+struct SignatureVerifier::VerifyContext {
+  ScopedOpenSSL<EVP_PKEY, EVP_PKEY_free> public_key;
+  ScopedOpenSSL<EVP_MD_CTX, EVP_MD_CTX_destroy> ctx;
+};
+
+SignatureVerifier::SignatureVerifier()
+    : verify_context_(NULL) {
 }
 
 SignatureVerifier::~SignatureVerifier() {
+  Reset();
 }
 
 bool SignatureVerifier::VerifyInit(const uint8* signature_algorithm,
                                    int signature_algorithm_len,
                                    const uint8* signature,
                                    int signature_len,
                                    const uint8* public_key_info,
                                    int public_key_info_len) {
-  NOTIMPLEMENTED();
-  return false;
+  DCHECK(!verify_context_);
+  verify_context_ = new VerifyContext;
+  OpenSSLErrStackTracer err_tracer(FROM_HERE);
+
+  ScopedOpenSSL<X509_ALGOR, X509_ALGOR_free> algorithm(
+      d2i_X509_ALGOR(NULL, &signature_algorithm, signature_algorithm_len));
+  if (!algorithm.get())
+    return false;
+
+  const EVP_MD* digest = EVP_get_digestbyobj(algorithm.get()->algorithm);
+  DCHECK(digest);
+
+  signature_.assign(signature, signature + signature_len);
+
+  // BIO_new_mem_buf is not const aware, but it does not modify the buffer.
+  char* data = reinterpret_cast<char*>(const_cast<uint8*>(public_key_info));
+  ScopedOpenSSL<BIO, BIO_free_all> bio(BIO_new_mem_buf(data,
+                                                       public_key_info_len));
+  if (!bio.get())
+    return false;
+
+  verify_context_->public_key.reset(d2i_PUBKEY_bio(bio.get(), NULL));
+  if (!verify_context_->public_key.get())
+    return false;
+
+  verify_context_->ctx.reset(EVP_MD_CTX_create());
+  int rv = EVP_VerifyInit_ex(verify_context_->ctx.get(), digest, NULL);
+  return rv == 1;
 }
 
 void SignatureVerifier::VerifyUpdate(const uint8* data_part,
                                      int data_part_len) {
-  NOTIMPLEMENTED();
+  DCHECK(verify_context_);
+  OpenSSLErrStackTracer err_tracer(FROM_HERE);
+  int rv = EVP_VerifyUpdate(verify_context_->ctx.get(),
+                            data_part, data_part_len);
+  DCHECK_EQ(rv, 1);
 }
 
 bool SignatureVerifier::VerifyFinal() {
-  NOTIMPLEMENTED();
-  return false;
+  DCHECK(verify_context_);
+  OpenSSLErrStackTracer err_tracer(FROM_HERE);
+  int rv = EVP_VerifyFinal(verify_context_->ctx.get(),
+                           signature_.data(), signature_.size(),
+                           verify_context_->public_key.get());
+  DCHECK_GE(rv, 0);
+  Reset();
+  return rv == 1;
 }
 
 void SignatureVerifier::Reset() {
-  NOTIMPLEMENTED();
+  delete verify_context_;
+  verify_context_ = NULL;
+  signature_.clear();
 }
 
 }  // namespace base