Revert "[webcrypto] Add decrypt() for AES-CBC."

content/renderer/webcrypto/webcrypto_impl_nss.cc

Index: content/renderer/webcrypto/webcrypto_impl_nss.cc
diff --git a/content/renderer/webcrypto/webcrypto_impl_nss.cc b/content/renderer/webcrypto/webcrypto_impl_nss.cc
index 7b8917d16e97eebc23365b9293a1f412fd137039..6a62cb8f88f047954913a3468fe20b2601af489e 100644
--- a/content/renderer/webcrypto/webcrypto_impl_nss.cc
+++ b/content/renderer/webcrypto/webcrypto_impl_nss.cc
@@ -84,17 +84,23 @@ void ShrinkBuffer(WebKit::WebArrayBuffer* buffer, unsigned new_size) {
   *buffer = new_buffer;
 }
 
-bool AesCbcEncryptDecrypt(
-    CK_ATTRIBUTE_TYPE operation,
+}  // namespace
+
+void WebCryptoImpl::Init() {
+  crypto::EnsureNSSInit();
+}
+
+bool WebCryptoImpl::EncryptInternal(
     const WebKit::WebCryptoAlgorithm& algorithm,
     const WebKit::WebCryptoKey& key,
     const unsigned char* data,
     unsigned data_size,
     WebKit::WebArrayBuffer* buffer) {
-  DCHECK_EQ(WebKit::WebCryptoAlgorithmIdAesCbc, algorithm.id());
+  if (algorithm.id() != WebKit::WebCryptoAlgorithmIdAesCbc)
+    return false;
+
   DCHECK_EQ(algorithm.id(), key.algorithm().id());
   DCHECK_EQ(WebKit::WebCryptoKeyTypeSecret, key.type());
-  DCHECK(operation == CKA_ENCRYPT || operation == CKA_DECRYPT);
 
   SymKeyHandle* sym_key = reinterpret_cast<SymKeyHandle*>(key.handle());
 
@@ -112,7 +118,7 @@ bool AesCbcEncryptDecrypt(
     return false;
 
   crypto::ScopedPK11Context context(PK11_CreateContextBySymKey(
-      CKM_AES_CBC_PAD, operation, sym_key->key(), param.get()));
+      CKM_AES_CBC_PAD, CKA_ENCRYPT, sym_key->key(), param.get()));
 
   if (!context.get())
     return false;
@@ -127,8 +133,6 @@ bool AesCbcEncryptDecrypt(
     return false;
   }
 
-  // TODO(eroman): Refine the output buffer size. It can be computed exactly for
-  //               encryption, and can be smaller for decryption.
   unsigned output_max_len = data_size + AES_BLOCK_SIZE;
   CHECK_GT(output_max_len, data_size);
 
@@ -158,40 +162,6 @@ bool AesCbcEncryptDecrypt(
   return true;
 }
 
-}  // namespace
-
-void WebCryptoImpl::Init() {
-  crypto::EnsureNSSInit();
-}
-
-bool WebCryptoImpl::EncryptInternal(
-    const WebKit::WebCryptoAlgorithm& algorithm,
-    const WebKit::WebCryptoKey& key,
-    const unsigned char* data,
-    unsigned data_size,
-    WebKit::WebArrayBuffer* buffer) {
-  if (algorithm.id() == WebKit::WebCryptoAlgorithmIdAesCbc) {
-    return AesCbcEncryptDecrypt(
-        CKA_ENCRYPT, algorithm, key, data, data_size, buffer);
-  }
-
-  return false;
-}
-
-bool WebCryptoImpl::DecryptInternal(
-    const WebKit::WebCryptoAlgorithm& algorithm,
-    const WebKit::WebCryptoKey& key,
-    const unsigned char* data,
-    unsigned data_size,
-    WebKit::WebArrayBuffer* buffer) {
-  if (algorithm.id() == WebKit::WebCryptoAlgorithmIdAesCbc) {
-    return AesCbcEncryptDecrypt(
-        CKA_DECRYPT, algorithm, key, data, data_size, buffer);
-  }
-
-  return false;
-}
-
 bool WebCryptoImpl::DigestInternal(
     const WebKit::WebCryptoAlgorithm& algorithm,
     const unsigned char* data,