Add SignatureVerifier::VerifyInitRSAPSS for verifying RSA-PSS signatures.

crypto/signature_verifier_nss.cc

 // Copyright (c) 2011 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_verifier.h"
 
 #include <cryptohi.h>
 #include <keyhi.h>
+#include <pk11pub.h>
+#include <secerr.h>
+#include <sechash.h>
 #include <stdlib.h>
 
 #include "base/logging.h"
 #include "crypto/nss_util.h"
+#include "crypto/third_party/nss/chromium-nss.h"
 
 namespace crypto {
 
-SignatureVerifier::SignatureVerifier() : vfy_context_(NULL) {
+namespace {
+
+HASH_HashType ToNSSHashType(SignatureVerifier::HashAlgorithm hash_alg) {
+  switch (hash_alg) {
+    case SignatureVerifier::SHA1:
+      return HASH_AlgSHA1;
+    case SignatureVerifier::SHA256:
+      return HASH_AlgSHA256;
+    default:
+      return HASH_AlgNULL;
+  }
+}
+
+SECStatus VerifyRSAPSS_End(SECKEYPublicKey* public_key,
+                           HASHContext* hash_context,
+                           HASH_HashType mask_hash_alg,
+                           unsigned int salt_len,
+                           const unsigned char* signature,
+                           unsigned int signature_len) {
+  unsigned int hash_len = HASH_ResultLenContext(hash_context);
+  std::vector<unsigned char> hash(hash_len);
+  HASH_End(hash_context, &hash[0], &hash_len, hash.size());
+
+  unsigned int modulus_len = SECKEY_PublicKeyStrength(public_key);
+  if (signature_len != modulus_len) {
+    PORT_SetError(SEC_ERROR_BAD_SIGNATURE);
+    return SECFailure;
+  }
+  std::vector<unsigned char> enc(signature_len);
+  SECStatus rv = PK11_PubEncryptRaw(public_key, &enc[0],
+                                    const_cast<unsigned char*>(signature),
+                                    signature_len, NULL);
+  if (rv != SECSuccess) {
+    LOG(WARNING) << "PK11_PubEncryptRaw failed";
+    return rv;
+  }
+  return emsa_pss_verify(&hash[0], &enc[0], enc.size(),
+                         HASH_GetType(hash_context), mask_hash_alg,
+                         salt_len);
+}
+
+}  // namespace
+
+SignatureVerifier::SignatureVerifier()
+    : vfy_context_(NULL),
+      hash_alg_(SHA1),
+      mask_hash_alg_(SHA1),
+      salt_len_(0),
+      public_key_(NULL),
+      hash_context_(NULL) {
   EnsureNSSInit();
 }
 
 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) {
-  signature_.assign(signature, signature + signature_len);
-
+// static
+SECKEYPublicKey* SignatureVerifier::DecodePublicKeyInfo(
+    const uint8* public_key_info,
+    int public_key_info_len) {
   CERTSubjectPublicKeyInfo* spki = NULL;
   SECItem spki_der;
   spki_der.type = siBuffer;
   spki_der.data = const_cast<uint8*>(public_key_info);
   spki_der.len = public_key_info_len;
   spki = SECKEY_DecodeDERSubjectPublicKeyInfo(&spki_der);
   if (!spki)
-    return false;
+    return NULL;
   SECKEYPublicKey* public_key = SECKEY_ExtractPublicKey(spki);
   SECKEY_DestroySubjectPublicKeyInfo(spki);  // Done with spki.
+  return public_key;
+}
+
+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) {

[Ryan Sleevi, 2013/06/26 19:48:28]

Can you make it an error to call VerifyInit() and VerifyInitRSAPSS() without
having called Final (eg: to make sure no one attempts to re-initialize a
SignatureVerifier)

[wtc, 2013/06/27 02:23:51]

Done.

+  signature_.assign(signature, signature + signature_len);
+
+  SECKEYPublicKey* public_key = DecodePublicKeyInfo(public_key_info,
+                                                    public_key_info_len);
   if (!public_key)
     return false;
 
   PLArenaPool* arena = PORT_NewArena(DER_DEFAULT_CHUNKSIZE);
   if (!arena) {
     SECKEY_DestroyPublicKey(public_key);
     return false;
   }
 
   SECItem sig_alg_der;
@@ skipping 29 matching lines @@
   }
 
   rv = VFY_Begin(vfy_context_);
   if (rv != SECSuccess) {
     NOTREACHED();
     return false;
   }
   return true;
 }
 
+bool SignatureVerifier::VerifyInitRSAPSS(HashAlgorithm hash_alg,
+                                         HashAlgorithm mask_hash_alg,
+                                         int salt_len,
+                                         const uint8* signature,
+                                         int signature_len,
+                                         const uint8* public_key_info,
+                                         int public_key_info_len) {
+  signature_.assign(signature, signature + signature_len);
+
+  SECKEYPublicKey* public_key = DecodePublicKeyInfo(public_key_info,
+                                                    public_key_info_len);
+  if (!public_key)
+    return false;
+
+  public_key_ = public_key;
+  hash_alg_ = hash_alg;
+  mask_hash_alg_ = mask_hash_alg;
+  salt_len_ = salt_len;
+  hash_context_ = HASH_Create(ToNSSHashType(hash_alg_));
+  if (!hash_context_)
+    return false;
+  HASH_Begin(hash_context_);
+  return true;
+}
+
 void SignatureVerifier::VerifyUpdate(const uint8* data_part,
                                      int data_part_len) {
-  SECStatus rv = VFY_Update(vfy_context_, data_part, data_part_len);
-  DCHECK_EQ(SECSuccess, rv);
+  if (vfy_context_) {
+    SECStatus rv = VFY_Update(vfy_context_, data_part, data_part_len);
+    DCHECK_EQ(SECSuccess, rv);
+  } else {
+    HASH_Update(hash_context_, data_part, data_part_len);
+  }
 }
 
 bool SignatureVerifier::VerifyFinal() {
-  SECStatus rv = VFY_End(vfy_context_);
+  SECStatus rv;
+  if (vfy_context_) {
+    rv = VFY_End(vfy_context_);
+  } else {
+    rv = VerifyRSAPSS_End(public_key_, hash_context_,
+                          ToNSSHashType(mask_hash_alg_), salt_len_,
+                          signature_.data(),
+                          signature_.size());
+  }
   Reset();
 
   // If signature verification fails, the error code is
   // SEC_ERROR_BAD_SIGNATURE (-8182).
   return (rv == SECSuccess);
 }
 
 void SignatureVerifier::Reset() {
   if (vfy_context_) {
     VFY_DestroyContext(vfy_context_, PR_TRUE);
     vfy_context_ = NULL;
   }
+  if (hash_context_) {
+    HASH_Destroy(hash_context_);
+    hash_context_ = NULL;
+  }
+  if (public_key_) {
+    SECKEY_DestroyPublicKey(public_key_);
+    public_key_ = NULL;
+  }
   signature_.clear();

[Ryan Sleevi, 2013/06/26 19:48:28]

LEAK? What happens to public_key_ here. Seems like it doesn't end up getting
destroyed.

[wtc, 2013/06/27 02:23:51]

public_key_ is destroyed on lines 214-217 above.

 }
 
 }  // namespace crypto