Add a CreatePSS method to SignatureCreator to permit the generation of PSS signatures.

crypto/signature_creator_openssl.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 <openssl/evp.h>
 #include <openssl/rsa.h>
 
 #include "base/logging.h"
@@ skipping 22 matching lines @@
     case SignatureCreator::SHA1:
       return NID_sha1;
     case SignatureCreator::SHA256:
       return NID_sha256;
   }
   return NID_undef;
 }
 
 }  // namespace
 
+SignatureCreator* SignatureCreator::Create(RSAPrivateKey* key,
+                                           HashAlgorithm hash_algm) {

[davidben, 2015/08/21 21:52:23]

Nit: hash_alg, to be consistent?

+  return SignatureCreator::CreateImpl(key, hash_algm, false);
+}
+
+SignatureCreator* SignatureCreator::CreatePSS(RSAPrivateKey* key,
+                                              HashAlgorithm hash_algm) {
+  return SignatureCreator::CreateImpl(key, hash_algm, true);
+}
+
 // static
-SignatureCreator* SignatureCreator::Create(RSAPrivateKey* key,
-                                           HashAlgorithm hash_alg) {
+SignatureCreator* SignatureCreator::CreateImpl(RSAPrivateKey* key,
+                                               HashAlgorithm hash_alg,
+                                               bool use_pss) {
   OpenSSLErrStackTracer err_tracer(FROM_HERE);
   scoped_ptr<SignatureCreator> result(new SignatureCreator);
   const EVP_MD* const digest = ToOpenSSLDigest(hash_alg);
   DCHECK(digest);
   if (!digest) {
     return NULL;
   }
-  if (!EVP_DigestSignInit(result->sign_context_, NULL, digest, NULL,
+  EVP_PKEY_CTX* pkey_ctx;
+  if (!EVP_DigestSignInit(result->sign_context_, &pkey_ctx, digest, NULL,
                           key->key())) {
     return NULL;
   }
+  if (use_pss) {
+    if (1 != EVP_PKEY_CTX_set_rsa_padding(pkey_ctx, RSA_PKCS1_PSS_PADDING)) {

[davidben, 2015/08/21 21:52:23]

You can just use ! now. BoringSSL narrowed both of these functions to return 0
or 1 like civilized people do.

+      LOG(FATAL) << "EVP_PKEY_CTX_set_rsa_padding";
+    }
+    // -1 sets the salt length to the digest length.
+    if (1 != EVP_PKEY_CTX_set_rsa_pss_saltlen(pkey_ctx, -1)) {
+      LOG(FATAL) << "EVP_PKEY_CTX_set_rsa_pss_saltlen";
+    }
+  }
   return result.release();
 }
 
 // static
 bool SignatureCreator::Sign(RSAPrivateKey* key,
                             HashAlgorithm hash_alg,
                             const uint8* data,
                             int data_len,
                             std::vector<uint8>* signature) {
   ScopedRSA rsa_key(EVP_PKEY_get1_RSA(key->key()));
@@ skipping 38 matching lines @@
   // Sign it.
   if (!EVP_DigestSignFinal(sign_context_, vector_as_array(signature), &len)) {
     signature->clear();
     return false;
   }
   signature->resize(len);
   return true;
 }
 
 }  // namespace crypto