Implement HKDF for WebCrypto (blink-side)

Source/modules/crypto/NormalizeAlgorithm.cpp

 /*
  * Copyright (C) 2013 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 49 matching lines @@
 
 #if ENABLE(ASSERT)
     bool operator<(const AlgorithmNameMapping&) const;
 #endif
 };
 
 // Must be sorted by length, and then by reverse string.
 // Also all names must be upper case ASCII.
 const AlgorithmNameMapping algorithmNameMappings[] = {
     {"HMAC", 4, WebCryptoAlgorithmIdHmac},
+    {"HKDF", 4, WebCryptoAlgorithmIdHkdf},
     {"ECDH", 4, WebCryptoAlgorithmIdEcdh},
     {"SHA-1", 5, WebCryptoAlgorithmIdSha1},
     {"ECDSA", 5, WebCryptoAlgorithmIdEcdsa},
     {"AES-KW", 6, WebCryptoAlgorithmIdAesKw},
     {"SHA-512", 7, WebCryptoAlgorithmIdSha512},
     {"SHA-384", 7, WebCryptoAlgorithmIdSha384},
     {"SHA-256", 7, WebCryptoAlgorithmIdSha256},
     {"AES-CBC", 7, WebCryptoAlgorithmIdAesCbc},
     {"AES-GCM", 7, WebCryptoAlgorithmIdAesGcm},
     {"AES-CTR", 7, WebCryptoAlgorithmIdAesCtr},
@@ skipping 686 matching lines @@
 bool parseAesDerivedKeyParams(const Dictionary& raw, OwnPtr<WebCryptoAlgorithmParams>& params, const ErrorContext& context, AlgorithmError* error)
 {
     uint16_t length;
     if (!getUint16(raw, "length", length, context, error))
         return false;
 
     params = adoptPtr(new WebCryptoAesDerivedKeyParams(length));
     return true;
 }
 
+// FIXME: once the spec has been updated, check that the implementation is
+// still correct and update this comment. http://crbug.com/399095
+//
+// The WebCrypto spec hasn't been updated yet to define HKDF. I am assuming a

[eroman, 2015/01/07 00:40:31]

Leave out things like "we" and "I" as it is unclear who is speaking. Phrase more
generally like:

"The WebCrypto spec hasn't been updated yet to define HKDF <Link to spec bug>.
The assumed parameters are:"

[nharper, 2015/01/08 00:58:39]

Done.

+// definition along the lines of:
+//
+//    dictionary HkdfParams : Algorithm {
+//      required HashAlgorithmIdentifier hash;
+//      required BufferSource salt;
+//      required BufferSource info;
+//    };
+bool parseHkdfParams(const Dictionary& raw, OwnPtr<WebCryptoAlgorithmParams>& params, const ErrorContext& context, AlgorithmError* error)
+{
+    WebCryptoAlgorithm hash;
+    if (!parseHash(raw, hash, context, error))
+        return false;
+    BufferSource saltBufferSource;
+    if (!getBufferSource(raw, "salt", saltBufferSource, context, error))
+        return false;
+    BufferSource infoBufferSource;
+    if (!getBufferSource(raw, "info", infoBufferSource, context, error))
+        return false;
+
+    DOMArrayPiece salt(saltBufferSource);
+    DOMArrayPiece info(infoBufferSource);
+
+    params = adoptPtr(new WebCryptoHkdfParams(hash, salt.bytes(), salt.byteLength(), info.bytes(), info.byteLength()));
+    return true;
+}
+
 bool parseAlgorithmParams(const Dictionary& raw, WebCryptoAlgorithmParamsType type, OwnPtr<WebCryptoAlgorithmParams>& params, ErrorContext& context, AlgorithmError* error)
 {
     switch (type) {
     case WebCryptoAlgorithmParamsTypeNone:
         return true;
     case WebCryptoAlgorithmParamsTypeAesCbcParams:
         context.add("AesCbcParams");
         return parseAesCbcParams(raw, params, context, error);
     case WebCryptoAlgorithmParamsTypeAesKeyGenParams:
         context.add("AesKeyGenParams");
@@ skipping 30 matching lines @@
         return parseEcKeyGenParams(raw, params, context, error);
     case WebCryptoAlgorithmParamsTypeEcKeyImportParams:
         context.add("EcKeyImportParams");
         return parseEcKeyImportParams(raw, params, context, error);
     case WebCryptoAlgorithmParamsTypeEcdhKeyDeriveParams:
         context.add("EcdhKeyDeriveParams");
         return parseEcdhKeyDeriveParams(raw, params, context, error);
     case WebCryptoAlgorithmParamsTypeAesDerivedKeyParams:
         context.add("AesDerivedKeyParams");
         return parseAesDerivedKeyParams(raw, params, context, error);
+    case WebCryptoAlgorithmParamsTypeHkdfParams:
+        context.add("HkdfParams");
+        return parseHkdfParams(raw, params, context, error);
     }
     ASSERT_NOT_REACHED();
     return false;
 }
 
 const char* operationToString(WebCryptoOperation op)
 {
     switch (op) {
     case WebCryptoOperationEncrypt:
         return "encrypt";
@@ skipping 77 matching lines @@
 }
 
 } // namespace
 
 bool normalizeAlgorithm(const AlgorithmIdentifier& raw, WebCryptoOperation op, WebCryptoAlgorithm& algorithm, AlgorithmError* error)
 {
     return parseAlgorithmIdentifier(raw, op, algorithm, ErrorContext(), error);
 }
 
 } // namespace blink