Generalize crypto::SignatureCreator to allow choice of hash function, so as to support SHA256 (not …

crypto/signature_creator_nss.cc

 // Copyright (c) 2012 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 "crypto/signature_creator.h"
 
 #include <cryptohi.h>
 #include <keyhi.h>
 #include <stdlib.h>
 
 #include "base/logging.h"
 #include "base/memory/scoped_ptr.h"
 #include "crypto/nss_util.h"
 #include "crypto/rsa_private_key.h"
 
 namespace crypto {
 
+namespace {
+
+SECOidTag ToNSSSigOid(SignatureCreator::HashAlgorithm hash_alg) {
+  switch (hash_alg) {
+    case SignatureCreator::SHA1:
+      return SEC_OID_PKCS1_SHA1_WITH_RSA_ENCRYPTION;
+    case SignatureCreator::SHA256:
+      return SEC_OID_PKCS1_SHA256_WITH_RSA_ENCRYPTION;
+  }
+  return SEC_OID_UNKNOWN;
+}
+
+SECOidTag ToNSSHashOid(SignatureCreator::HashAlgorithm hash_alg) {
+  switch (hash_alg) {
+    case SignatureCreator::SHA1:
+      return SEC_OID_SHA1;
+    case SignatureCreator::SHA256:
+      return SEC_OID_SHA256;
+  }
+  return SEC_OID_UNKNOWN;
+}
+
+}  // namespace
+
 SignatureCreator::~SignatureCreator() {
   if (sign_context_) {
     SGN_DestroyContext(sign_context_, PR_TRUE);
     sign_context_ = NULL;
   }
 }
 
 // static
 SignatureCreator* SignatureCreator::Create(RSAPrivateKey* key) {
+  return CreateUsingSpecifiedHash(key, SignatureCreator::SHA1);
+}
+
+// static
+SignatureCreator* SignatureCreator::CreateUsingSpecifiedHash(
+    RSAPrivateKey* key,
+    HashAlgorithm hash_alg) {
   scoped_ptr<SignatureCreator> result(new SignatureCreator);
   result->key_ = key;
 
-  result->sign_context_ = SGN_NewContext(SEC_OID_PKCS1_SHA1_WITH_RSA_ENCRYPTION,
-      key->key());
+  result->sign_context_ = SGN_NewContext(ToNSSSigOid(hash_alg), key->key());
   if (!result->sign_context_) {
     NOTREACHED();
     return NULL;
   }
 
   SECStatus rv = SGN_Begin(result->sign_context_);
   if (rv != SECSuccess) {
     NOTREACHED();
     return NULL;
   }
 
   return result.release();
 }
 
 // static
 bool SignatureCreator::Sign(RSAPrivateKey* key,
                             const uint8* data,
                             int data_len,
                             std::vector<uint8>* signature) {
+  return SignUsingSpecifiedHash(
+      key, SignatureCreator::SHA1, data, data_len, signature);
+}
+
+// static
+bool SignatureCreator::SignUsingSpecifiedHash(RSAPrivateKey* key,
+                                              HashAlgorithm hash_alg,
+                                              const uint8* data,
+                                              int data_len,
+                                              std::vector<uint8>* signature) {
   SECItem data_item;
   data_item.type = siBuffer;
   data_item.data = const_cast<unsigned char*>(data);
   data_item.len = data_len;
 
   SECItem signature_item;
-  SECStatus rv = SGN_Digest(key->key(), SEC_OID_SHA1, &signature_item,
+  SECStatus rv = SGN_Digest(key->key(), ToNSSHashOid(hash_alg), &signature_item,
                             &data_item);
   if (rv != SECSuccess) {
     NOTREACHED();
     return false;
   }
   signature->assign(signature_item.data,
                     signature_item.data + signature_item.len);
   SECITEM_FreeItem(&signature_item, PR_FALSE);
   return true;
 }
@@ skipping 20 matching lines @@
   return true;
 }
 
 SignatureCreator::SignatureCreator()
     : key_(NULL),
       sign_context_(NULL) {
   EnsureNSSInit();
 }
 
 }  // namespace crypto