WebCrypto: Add algorithm normalization rules for RSASSA-PKCS1-v1_5.

Source/modules/crypto/NormalizeAlgorithm.cpp

Index: Source/modules/crypto/NormalizeAlgorithm.cpp
diff --git a/Source/modules/crypto/NormalizeAlgorithm.cpp b/Source/modules/crypto/NormalizeAlgorithm.cpp
index 630580c4f51ac78aa15866550b64d234f0fddb8b..52f9dc8604b6f0f84744c477d86c58877dbb0cb6 100644
--- a/Source/modules/crypto/NormalizeAlgorithm.cpp
+++ b/Source/modules/crypto/NormalizeAlgorithm.cpp
@@ -67,6 +67,7 @@ struct OperationParamsMapping {
 const AlgorithmNameMapping algorithmNameMappings[] = {
     {"AES-CBC", WebKit::WebCryptoAlgorithmIdAesCbc},
     {"HMAC", WebKit::WebCryptoAlgorithmIdHmac},
+    {"RSASSA-PKCS1-v1_5", WebKit::WebCryptoAlgorithmIdRsaSsaPkcs1v1_5},
     {"SHA-1", WebKit::WebCryptoAlgorithmIdSha1},
     {"SHA-224", WebKit::WebCryptoAlgorithmIdSha224},
     {"SHA-256", WebKit::WebCryptoAlgorithmIdSha256},
@@ -88,6 +89,12 @@ const OperationParamsMapping operationParamsMappings[] = {
     {WebKit::WebCryptoAlgorithmIdHmac, GenerateKey, WebKit::WebCryptoAlgorithmParamsTypeHmacParams},
     {WebKit::WebCryptoAlgorithmIdHmac, ImportKey, WebKit::WebCryptoAlgorithmParamsTypeHmacParams},
 
+    // RSASSA-PKCS1-v1_5 (section 18.4.)
+    {WebKit::WebCryptoAlgorithmIdRsaSsaPkcs1v1_5, Sign, WebKit::WebCryptoAlgorithmParamsTypeRsaSsaParams},
+    {WebKit::WebCryptoAlgorithmIdRsaSsaPkcs1v1_5, Verify, WebKit::WebCryptoAlgorithmParamsTypeRsaSsaParams},
+    {WebKit::WebCryptoAlgorithmIdRsaSsaPkcs1v1_5, GenerateKey, WebKit::WebCryptoAlgorithmParamsTypeRsaKeyGenParams},
+    {WebKit::WebCryptoAlgorithmIdRsaSsaPkcs1v1_5, ImportKey, WebKit::WebCryptoAlgorithmParamsTypeNone},
+
     // SHA-1 (section 18.16.)
     {WebKit::WebCryptoAlgorithmIdSha1, Digest, WebKit::WebCryptoAlgorithmParamsTypeNone},
 
@@ -183,20 +190,45 @@ PassOwnPtr<WebKit::WebCryptoAlgorithmParams> parseAesKeyGenParams(const Dictiona
     return adoptPtr(new WebKit::WebCryptoAesKeyGenParams(length));
 }
 
-PassOwnPtr<WebKit::WebCryptoAlgorithmParams> parseHmacParams(const Dictionary& raw)
+bool parseHash(const Dictionary& raw, WebKit::WebCryptoAlgorithm& hash)
 {
     Dictionary rawHash;
     if (!raw.get("hash", rawHash))
+        return false;
+
+    NonThrowExceptionState es;
+    return normalizeAlgorithm(rawHash, Digest, hash, es);
+}
+
+PassOwnPtr<WebKit::WebCryptoAlgorithmParams> parseHmacParams(const Dictionary& raw)
+{
+    WebKit::WebCryptoAlgorithm hash;
+    if (!parseHash(raw, hash))
         return nullptr;
+    return adoptPtr(new WebKit::WebCryptoHmacParams(hash));
+}
 
-    // Normalizing the algorithm for a Digest operation means it will only
-    // match the SHA-* algorithms.
+PassOwnPtr<WebKit::WebCryptoAlgorithmParams> parseRsaSsaParams(const Dictionary& raw)
+{
     WebKit::WebCryptoAlgorithm hash;
-    NonThrowExceptionState es;
-    if (!normalizeAlgorithm(rawHash, Digest, hash, es))
+    if (!parseHash(raw, hash))
         return nullptr;
+    return adoptPtr(new WebKit::WebCryptoRsaSsaParams(hash));
+}
 
-    return adoptPtr(new WebKit::WebCryptoHmacParams(hash));
+PassOwnPtr<WebKit::WebCryptoAlgorithmParams> parseRsaKeyGenParams(const Dictionary& raw)
+{
+    // FIXME: This is losing precision; modulusLength is supposed to be a uint32

[abarth-chromium, 2013/08/02 17:56:56]

Should we make dictionary understand uint32?  I don't think numbers that large
are representable in JavaScript anyway.

[eroman, 2013/08/02 19:25:42]

I need to do a bit of follow-up on what WebIDL intends here.

Here is the thing: Dictionary already has methods for extracting unsigned
numbers:

  Dictionary::get(const String& key, unsigned& value);

The problem is in its implemnetation, it simply gets an Int32, and then does a
static_cast<unsigned>() on it.

So that means, if the user passed in "-1", then it would complete successfully
and return to me 0xFFFFFFFF.

I am not sure if this is what the WebCrypto spec intends, but it seems wrong to
me. I would reject negative numbers than silently convert them to large numbers
in twos complement.

I could use the existing method:
   Dictionary::get(const String& key, double& value)

And then do the sign test before converting to an "unsigned". But I wanted to do
a bit more research before I tackle this.

As I recall, JavaScript can accurately represent up to 53-bit integers using
floating point representation, so that would be fine for extracting my 32-bit
unsigned value.

Although it does seem strange to allow fractional numbers in Javascript (like a
key length of 1024.9), and then have that magically truncated to 1024.9.

Note that with the integer method I am using now, fractional numbers are also
allowed.

+    int32_t modulusLength;
+    if (!raw.get("modulusLength", modulusLength))
+        return nullptr;
+    if (modulusLength < 0)
+        return nullptr;
+
+    RefPtr<Uint8Array> publicExponent;
+    if (!raw.get("publicExponent", publicExponent) || !publicExponent)
+        return nullptr;
+    return adoptPtr(new WebKit::WebCryptoRsaKeyGenParams(modulusLength, static_cast<const unsigned char*>(publicExponent->baseAddress()), publicExponent->byteLength()));
 }
 
 PassOwnPtr<WebKit::WebCryptoAlgorithmParams> parseAlgorithmParams(const Dictionary& raw, WebKit::WebCryptoAlgorithmParamsType type)
@@ -210,6 +242,10 @@ PassOwnPtr<WebKit::WebCryptoAlgorithmParams> parseAlgorithmParams(const Dictiona
         return parseAesKeyGenParams(raw);
     case WebKit::WebCryptoAlgorithmParamsTypeHmacParams:
         return parseHmacParams(raw);
+    case WebKit::WebCryptoAlgorithmParamsTypeRsaSsaParams:
+        return parseRsaSsaParams(raw);
+    case WebKit::WebCryptoAlgorithmParamsTypeRsaKeyGenParams:
+        return parseRsaKeyGenParams(raw);
     }
     ASSERT_NOT_REACHED();
     return nullptr;