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      1 /*
      2  * Copyright (C) 2013 Google Inc. All rights reserved.
      3  *
      4  * Redistribution and use in source and binary forms, with or without
      5  * modification, are permitted provided that the following conditions are
      6  * met:
      7  *
      8  *     * Redistributions of source code must retain the above copyright
      9  * notice, this list of conditions and the following disclaimer.
     10  *     * Redistributions in binary form must reproduce the above
     11  * copyright notice, this list of conditions and the following disclaimer
     12  * in the documentation and/or other materials provided with the
     13  * distribution.
     14  *     * Neither the name of Google Inc. nor the names of its
     15  * contributors may be used to endorse or promote products derived from
     16  * this software without specific prior written permission.
     17  *
     18  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
     19  * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
     20  * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
     21  * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
     22  * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
     23  * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
     24  * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
     25  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
     26  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
     27  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
     28  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
     29  */
     30 
     31 #include "config.h"
     32 #include "modules/crypto/Key.h"
     33 
     34 #include "bindings/v8/ExceptionState.h"
     35 #include "core/dom/ExceptionCode.h"
     36 #include "modules/crypto/KeyAlgorithm.h"
     37 #include "platform/CryptoResult.h"
     38 #include "public/platform/WebCryptoAlgorithmParams.h"
     39 #include "public/platform/WebString.h"
     40 
     41 namespace WebCore {
     42 
     43 namespace {
     44 
     45 const char* keyTypeToString(blink::WebCryptoKeyType type)
     46 {
     47     switch (type) {
     48     case blink::WebCryptoKeyTypeSecret:
     49         return "secret";
     50     case blink::WebCryptoKeyTypePublic:
     51         return "public";
     52     case blink::WebCryptoKeyTypePrivate:
     53         return "private";
     54     }
     55     ASSERT_NOT_REACHED();
     56     return 0;
     57 }
     58 
     59 struct KeyUsageMapping {
     60     blink::WebCryptoKeyUsage value;
     61     const char* const name;
     62 };
     63 
     64 // The order of this array is the same order that will appear in Key.usages. It
     65 // must be kept ordered as described by the Web Crypto spec.
     66 const KeyUsageMapping keyUsageMappings[] = {
     67     { blink::WebCryptoKeyUsageEncrypt, "encrypt" },
     68     { blink::WebCryptoKeyUsageDecrypt, "decrypt" },
     69     { blink::WebCryptoKeyUsageSign, "sign" },
     70     { blink::WebCryptoKeyUsageVerify, "verify" },
     71     { blink::WebCryptoKeyUsageDeriveKey, "deriveKey" },
     72     { blink::WebCryptoKeyUsageDeriveBits, "deriveBits" },
     73     { blink::WebCryptoKeyUsageWrapKey, "wrapKey" },
     74     { blink::WebCryptoKeyUsageUnwrapKey, "unwrapKey" },
     75 };
     76 
     77 COMPILE_ASSERT(blink::EndOfWebCryptoKeyUsage == (1 << 7) + 1, update_keyUsageMappings);
     78 
     79 const char* keyUsageToString(blink::WebCryptoKeyUsage usage)
     80 {
     81     for (size_t i = 0; i < WTF_ARRAY_LENGTH(keyUsageMappings); ++i) {
     82         if (keyUsageMappings[i].value == usage)
     83             return keyUsageMappings[i].name;
     84     }
     85     ASSERT_NOT_REACHED();
     86     return 0;
     87 }
     88 
     89 blink::WebCryptoKeyUsageMask keyUsageStringToMask(const String& usageString)
     90 {
     91     for (size_t i = 0; i < WTF_ARRAY_LENGTH(keyUsageMappings); ++i) {
     92         if (keyUsageMappings[i].name == usageString)
     93             return keyUsageMappings[i].value;
     94     }
     95     return 0;
     96 }
     97 
     98 blink::WebCryptoKeyUsageMask toKeyUsage(blink::WebCryptoOperation operation)
     99 {
    100     switch (operation) {
    101     case blink::WebCryptoOperationEncrypt:
    102         return blink::WebCryptoKeyUsageEncrypt;
    103     case blink::WebCryptoOperationDecrypt:
    104         return blink::WebCryptoKeyUsageDecrypt;
    105     case blink::WebCryptoOperationSign:
    106         return blink::WebCryptoKeyUsageSign;
    107     case blink::WebCryptoOperationVerify:
    108         return blink::WebCryptoKeyUsageVerify;
    109     case blink::WebCryptoOperationDeriveKey:
    110         return blink::WebCryptoKeyUsageDeriveKey;
    111     case blink::WebCryptoOperationDeriveBits:
    112         return blink::WebCryptoKeyUsageDeriveBits;
    113     case blink::WebCryptoOperationWrapKey:
    114         return blink::WebCryptoKeyUsageWrapKey;
    115     case blink::WebCryptoOperationUnwrapKey:
    116         return blink::WebCryptoKeyUsageUnwrapKey;
    117     case blink::WebCryptoOperationDigest:
    118     case blink::WebCryptoOperationGenerateKey:
    119     case blink::WebCryptoOperationImportKey:
    120         break;
    121     }
    122 
    123     ASSERT_NOT_REACHED();
    124     return 0;
    125 }
    126 
    127 } // namespace
    128 
    129 Key::~Key()
    130 {
    131 }
    132 
    133 Key::Key(const blink::WebCryptoKey& key)
    134     : m_key(key)
    135 {
    136     ScriptWrappable::init(this);
    137 }
    138 
    139 String Key::type() const
    140 {
    141     return keyTypeToString(m_key.type());
    142 }
    143 
    144 bool Key::extractable() const
    145 {
    146     return m_key.extractable();
    147 }
    148 
    149 KeyAlgorithm* Key::algorithm()
    150 {
    151     if (!m_algorithm)
    152         m_algorithm = KeyAlgorithm::create(m_key.algorithm());
    153     return m_algorithm.get();
    154 }
    155 
    156 // FIXME: This creates a new javascript array each time. What should happen
    157 //        instead is return the same (immutable) array. (Javascript callers can
    158 //        distinguish this by doing an == test on the arrays and seeing they are
    159 //        different).
    160 Vector<String> Key::usages() const
    161 {
    162     Vector<String> result;
    163     for (size_t i = 0; i < WTF_ARRAY_LENGTH(keyUsageMappings); ++i) {
    164         blink::WebCryptoKeyUsage usage = keyUsageMappings[i].value;
    165         if (m_key.usages() & usage)
    166             result.append(keyUsageToString(usage));
    167     }
    168     return result;
    169 }
    170 
    171 bool Key::canBeUsedForAlgorithm(const blink::WebCryptoAlgorithm& algorithm, blink::WebCryptoOperation op, CryptoResult* result) const
    172 {
    173     if (!(m_key.usages() & toKeyUsage(op))) {
    174         result->completeWithError(blink::WebCryptoErrorTypeInvalidAccess, "key.usages does not permit this operation");
    175         return false;
    176     }
    177 
    178     if (m_key.algorithm().id() != algorithm.id()) {
    179         result->completeWithError(blink::WebCryptoErrorTypeInvalidAccess, "key.algorithm does not match that of operation");
    180         return false;
    181     }
    182 
    183     return true;
    184 }
    185 
    186 bool Key::parseFormat(const String& formatString, blink::WebCryptoKeyFormat& format, CryptoResult* result)
    187 {
    188     // There are few enough values that testing serially is fast enough.
    189     if (formatString == "raw") {
    190         format = blink::WebCryptoKeyFormatRaw;
    191         return true;
    192     }
    193     if (formatString == "pkcs8") {
    194         format = blink::WebCryptoKeyFormatPkcs8;
    195         return true;
    196     }
    197     if (formatString == "spki") {
    198         format = blink::WebCryptoKeyFormatSpki;
    199         return true;
    200     }
    201     if (formatString == "jwk") {
    202         format = blink::WebCryptoKeyFormatJwk;
    203         return true;
    204     }
    205 
    206     result->completeWithError(blink::WebCryptoErrorTypeSyntax, "Invalid keyFormat argument");
    207     return false;
    208 }
    209 
    210 bool Key::parseUsageMask(const Vector<String>& usages, blink::WebCryptoKeyUsageMask& mask, CryptoResult* result)
    211 {
    212     mask = 0;
    213     for (size_t i = 0; i < usages.size(); ++i) {
    214         blink::WebCryptoKeyUsageMask usage = keyUsageStringToMask(usages[i]);
    215         if (!usage) {
    216             result->completeWithError(blink::WebCryptoErrorTypeSyntax, "Invalid keyUsages argument");
    217             return false;
    218         }
    219         mask |= usage;
    220     }
    221     return true;
    222 }
    223 
    224 void Key::trace(Visitor* visitor)
    225 {
    226     visitor->trace(m_algorithm);
    227 }
    228 
    229 } // namespace WebCore
    230