WebCrypto: Add framework for AlgorithmIdentifier normalization.

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
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+/*
+ * 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
+ * copyright notice, this list of conditions and the following disclaimer
+ * in the documentation and/or other materials provided with the
+ * distribution.
+ *     * Neither the name of Google Inc. nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+ * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+ * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+ * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+ * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "config.h"
+#include "modules/crypto/NormalizeAlgorithm.h"
+
+#include "bindings/v8/Dictionary.h"
+#include "core/dom/ExceptionCode.h"
+#include "public/platform/WebCryptoAlgorithm.h"
+#include "public/platform/WebCryptoAlgorithmParams.h"
+#include "wtf/ArrayBuffer.h"
+#include "wtf/ArrayBufferView.h"
+#include "wtf/HashMap.h"
+#include "wtf/Uint8Array.h"
+#include "wtf/Vector.h"
+#include "wtf/text/StringHash.h"
+
+namespace WebCore {
+
+namespace {
+
+struct AlgorithmNameMapping {
+    const char* const algorithmName;
+    WebKit::WebCryptoAlgorithmId algorithmId;
+};
+
+// Indicates that the algorithm doesn't support the specified operation.
+const int UnsupportedOp = -1;
+
+// Either UnsupportedOp, or a value from WebKit::WebCryptoAlgorithmParamsType
+typedef int AlgorithmParamsForOperation;
+
+struct OperationParamsMapping {
+    WebKit::WebCryptoAlgorithmId algorithmId;
+    AlgorithmOperation operation;
+    AlgorithmParamsForOperation params;
+};
+
+const AlgorithmNameMapping algorithmNameMappings[] = {
+    {"AES-CBC", WebKit::WebCryptoAlgorithmIdAesCbc},
+    {"SHA-1", WebKit::WebCryptoAlgorithmIdSha1},
+    {"SHA-224", WebKit::WebCryptoAlgorithmIdSha224},
+    {"SHA-256", WebKit::WebCryptoAlgorithmIdSha256},
+    {"SHA-384", WebKit::WebCryptoAlgorithmIdSha384},
+    {"SHA-512", WebKit::WebCryptoAlgorithmIdSha512},
+};
+
+// What operations each algorithm supports, and what parameters it expects.
+const OperationParamsMapping operationParamsMappings[] = {
+    // AES-CBC (section 18.10.)
+    {WebKit::WebCryptoAlgorithmIdAesCbc, Decrypt, WebKit::WebCryptoAlgorithmParamsTypeAesCbcParams},
+    {WebKit::WebCryptoAlgorithmIdAesCbc, Encrypt, WebKit::WebCryptoAlgorithmParamsTypeAesCbcParams},
+    {WebKit::WebCryptoAlgorithmIdAesCbc, GenerateKey, WebKit::WebCryptoAlgorithmParamsTypeAesKeyGenParams},
+
+    // SHA-1 (section 18.16.)
+    {WebKit::WebCryptoAlgorithmIdSha1, Digest, WebKit::WebCryptoAlgorithmParamsTypeNone},
+
+    // SHA-224 (section 18.16.)
+    {WebKit::WebCryptoAlgorithmIdSha224, Digest, WebKit::WebCryptoAlgorithmParamsTypeNone},
+
+    // SHA-256 (section 18.16.)
+    {WebKit::WebCryptoAlgorithmIdSha256, Digest, WebKit::WebCryptoAlgorithmParamsTypeNone},
+
+    // SHA-384 (section 18.16.)
+    {WebKit::WebCryptoAlgorithmIdSha384, Digest, WebKit::WebCryptoAlgorithmParamsTypeNone},
+
+    // SHA-512 (section 18.16.)
+    {WebKit::WebCryptoAlgorithmIdSha512, Digest, WebKit::WebCryptoAlgorithmParamsTypeNone},
+};
+
+// This structure describes an algorithm and its supported operations.
+struct AlgorithmInfo {
+    AlgorithmInfo()
+        : algorithmName(0)
+    {
+        for (size_t i = 0; i < WTF_ARRAY_LENGTH(paramsForOperation); ++i)
+            paramsForOperation[i] = UnsupportedOp;
+    }
+
+    WebKit::WebCryptoAlgorithmId algorithmId;
+    const char* algorithmName;
+    AlgorithmParamsForOperation paramsForOperation[NumberOfAlgorithmOperations];
+};
+
+// AlgorithmRegistry enumerates each of the different algorithms and its
+// parameters. This describes the same information as the static tables above,
+// but in a more convenient runtime form.
+class AlgorithmRegistry {
+public:
+    static const AlgorithmInfo* lookupAlgorithmByName(const String& algorithmName);
+
+private:
+    AlgorithmRegistry();
+
+    // Algorithm name to ID.
+    typedef HashMap<String, WebKit::WebCryptoAlgorithmId, CaseFoldingHash> AlgorithmNameToIdMap;
+    AlgorithmNameToIdMap m_algorithmNameToId;
+
+    // Algorithm ID to information.
+    AlgorithmInfo m_algorithms[WebKit::NumberOfWebCryptoAlgorithmId];
+};
+
+const AlgorithmInfo* AlgorithmRegistry::lookupAlgorithmByName(const String& algorithmName)
+{
+    DEFINE_STATIC_LOCAL(AlgorithmRegistry, registry, ());
+
+    AlgorithmNameToIdMap::const_iterator it = registry.m_algorithmNameToId.find(algorithmName);
+    if (it == registry.m_algorithmNameToId.end())
+        return 0;
+    return &registry.m_algorithms[it->value];
+}
+
+AlgorithmRegistry::AlgorithmRegistry()
+{
+    for (size_t i = 0; i < WTF_ARRAY_LENGTH(algorithmNameMappings); ++i) {
+        const AlgorithmNameMapping& mapping = algorithmNameMappings[i];
+        m_algorithmNameToId.add(mapping.algorithmName, mapping.algorithmId);
+        m_algorithms[mapping.algorithmId].algorithmName = mapping.algorithmName;
+    }
+
+    for (size_t i = 0; i < WTF_ARRAY_LENGTH(operationParamsMappings); ++i) {
+        const OperationParamsMapping& mapping = operationParamsMappings[i];
+        m_algorithms[mapping.algorithmId].paramsForOperation[mapping.operation] = mapping.params;
+    }
+}
+
+PassOwnPtr<WebKit::WebCryptoAlgorithmParams> parseAesCbcParams(const Dictionary& raw)
+{
+    RefPtr<ArrayBufferView> iv;
+    if (!raw.get("iv", iv) || !iv)
+        return nullptr;
+
+    if (iv->byteLength() != 16)
+        return nullptr;
+
+    return adoptPtr(new WebKit::WebCryptoAesCbcParams(static_cast<unsigned char*>(iv->baseAddress()), iv->byteLength()));
+}
+
+PassOwnPtr<WebKit::WebCryptoAlgorithmParams> parseAesKeyGenParams(const Dictionary& raw)
+{
+    int32_t length;
+    if (!raw.get("length", length))
+        return nullptr;
+    if (length < 0 || length > 0xFFFF)
+        return nullptr;
+    return adoptPtr(new WebKit::WebCryptoAesKeyGenParams(length));
+}
+
+PassOwnPtr<WebKit::WebCryptoAlgorithmParams> parseAlgorithmParams(const Dictionary& raw, WebKit::WebCryptoAlgorithmParamsType type)
+{
+    switch (type) {
+    case WebKit::WebCryptoAlgorithmParamsTypeNone:
+        return nullptr;
+    case WebKit::WebCryptoAlgorithmParamsTypeAesCbcParams:
+        return parseAesCbcParams(raw);
+    case WebKit::WebCryptoAlgorithmParamsTypeAesKeyGenParams:
+        return parseAesKeyGenParams(raw);
+    }
+    ASSERT_NOT_REACHED();
+    return nullptr;
+}
+
+} // namespace
+
+// FIXME: Throw the correct exception types!
+// This implementation corresponds with:
+// http://www.w3.org/TR/WebCryptoAPI/#algorithm-normalizing-rules
+bool normalizeAlgorithm(const Dictionary& raw, AlgorithmOperation op, WebKit::WebCryptoAlgorithm& algorithm, ExceptionCode& ec)
+{
+    String algorithmName;
+    if (!raw.get("name", algorithmName)) {
+        ec = NOT_SUPPORTED_ERR;
+        return false;
+    }
+
+    if (!algorithmName.containsOnlyASCII()) {
+        ec = SYNTAX_ERR;
+        return false;
+    }
+
+    const AlgorithmInfo* info = AlgorithmRegistry::lookupAlgorithmByName(algorithmName);
+    if (!info) {
+        ec = NOT_SUPPORTED_ERR;
+        return false;
+    }
+
+    if (info->paramsForOperation[op] == UnsupportedOp) {
+        ec = NOT_SUPPORTED_ERR;
+        return false;
+    }
+
+    WebKit::WebCryptoAlgorithmParamsType paramsType = static_cast<WebKit::WebCryptoAlgorithmParamsType>(info->paramsForOperation[op]);
+    OwnPtr<WebKit::WebCryptoAlgorithmParams> params = parseAlgorithmParams(raw, paramsType);
+
+    if (!params && paramsType != WebKit::WebCryptoAlgorithmParamsTypeNone) {
+        ec = NOT_SUPPORTED_ERR;
+        return false;
+    }
+
+    algorithm = WebKit::WebCryptoAlgorithm(info->algorithmId, info->algorithmName, params.release());
+    return true;
+}
+
+} // namespace WebCore