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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/CryptoKey.h"
     33 
     34 #include "bindings/core/v8/ExceptionState.h"
     35 #include "core/dom/ExceptionCode.h"
     36 #include "platform/CryptoResult.h"
     37 #include "public/platform/WebCryptoAlgorithmParams.h"
     38 #include "public/platform/WebCryptoKeyAlgorithm.h"
     39 #include "public/platform/WebString.h"
     40 
     41 namespace blink {
     42 
     43 namespace {
     44 
     45 const char* keyTypeToString(WebCryptoKeyType type)
     46 {
     47     switch (type) {
     48     case WebCryptoKeyTypeSecret:
     49         return "secret";
     50     case WebCryptoKeyTypePublic:
     51         return "public";
     52     case WebCryptoKeyTypePrivate:
     53         return "private";
     54     }
     55     ASSERT_NOT_REACHED();
     56     return 0;
     57 }
     58 
     59 struct KeyUsageMapping {
     60     WebCryptoKeyUsage value;
     61     const char* const name;
     62 };
     63 
     64 // The order of this array is the same order that will appear in
     65 // CryptoKey.usages. It must be kept ordered as described by the Web Crypto
     66 // spec.
     67 const KeyUsageMapping keyUsageMappings[] = {
     68     { WebCryptoKeyUsageEncrypt, "encrypt" },
     69     { WebCryptoKeyUsageDecrypt, "decrypt" },
     70     { WebCryptoKeyUsageSign, "sign" },
     71     { WebCryptoKeyUsageVerify, "verify" },
     72     { WebCryptoKeyUsageDeriveKey, "deriveKey" },
     73     { WebCryptoKeyUsageDeriveBits, "deriveBits" },
     74     { WebCryptoKeyUsageWrapKey, "wrapKey" },
     75     { WebCryptoKeyUsageUnwrapKey, "unwrapKey" },
     76 };
     77 
     78 COMPILE_ASSERT(EndOfWebCryptoKeyUsage == (1 << 7) + 1, update_keyUsageMappings);
     79 
     80 const char* keyUsageToString(WebCryptoKeyUsage usage)
     81 {
     82     for (size_t i = 0; i < WTF_ARRAY_LENGTH(keyUsageMappings); ++i) {
     83         if (keyUsageMappings[i].value == usage)
     84             return keyUsageMappings[i].name;
     85     }
     86     ASSERT_NOT_REACHED();
     87     return 0;
     88 }
     89 
     90 WebCryptoKeyUsageMask keyUsageStringToMask(const String& usageString)
     91 {
     92     for (size_t i = 0; i < WTF_ARRAY_LENGTH(keyUsageMappings); ++i) {
     93         if (keyUsageMappings[i].name == usageString)
     94             return keyUsageMappings[i].value;
     95     }
     96     return 0;
     97 }
     98 
     99 WebCryptoKeyUsageMask toKeyUsage(WebCryptoOperation operation)
    100 {
    101     switch (operation) {
    102     case WebCryptoOperationEncrypt:
    103         return WebCryptoKeyUsageEncrypt;
    104     case WebCryptoOperationDecrypt:
    105         return WebCryptoKeyUsageDecrypt;
    106     case WebCryptoOperationSign:
    107         return WebCryptoKeyUsageSign;
    108     case WebCryptoOperationVerify:
    109         return WebCryptoKeyUsageVerify;
    110     case WebCryptoOperationDeriveKey:
    111         return WebCryptoKeyUsageDeriveKey;
    112     case WebCryptoOperationDeriveBits:
    113         return WebCryptoKeyUsageDeriveBits;
    114     case WebCryptoOperationWrapKey:
    115         return WebCryptoKeyUsageWrapKey;
    116     case WebCryptoOperationUnwrapKey:
    117         return WebCryptoKeyUsageUnwrapKey;
    118     case WebCryptoOperationDigest:
    119     case WebCryptoOperationGenerateKey:
    120     case WebCryptoOperationImportKey:
    121         break;
    122     }
    123 
    124     ASSERT_NOT_REACHED();
    125     return 0;
    126 }
    127 
    128 } // namespace
    129 
    130 CryptoKey::~CryptoKey()
    131 {
    132 }
    133 
    134 CryptoKey::CryptoKey(const WebCryptoKey& key)
    135     : m_key(key)
    136 {
    137 }
    138 
    139 String CryptoKey::type() const
    140 {
    141     return keyTypeToString(m_key.type());
    142 }
    143 
    144 bool CryptoKey::extractable() const
    145 {
    146     return m_key.extractable();
    147 }
    148 
    149 // FIXME: This creates a new javascript array each time. What should happen
    150 //        instead is return the same (immutable) array. (Javascript callers can
    151 //        distinguish this by doing an == test on the arrays and seeing they are
    152 //        different).
    153 Vector<String> CryptoKey::usages() const
    154 {
    155     Vector<String> result;
    156     for (size_t i = 0; i < WTF_ARRAY_LENGTH(keyUsageMappings); ++i) {
    157         WebCryptoKeyUsage usage = keyUsageMappings[i].value;
    158         if (m_key.usages() & usage)
    159             result.append(keyUsageToString(usage));
    160     }
    161     return result;
    162 }
    163 
    164 bool CryptoKey::canBeUsedForAlgorithm(const WebCryptoAlgorithm& algorithm, WebCryptoOperation op, CryptoResult* result) const
    165 {
    166     if (!(m_key.usages() & toKeyUsage(op))) {
    167         result->completeWithError(WebCryptoErrorTypeInvalidAccess, "key.usages does not permit this operation");
    168         return false;
    169     }
    170 
    171     if (m_key.algorithm().id() != algorithm.id()) {
    172         result->completeWithError(WebCryptoErrorTypeInvalidAccess, "key.algorithm does not match that of operation");
    173         return false;
    174     }
    175 
    176     return true;
    177 }
    178 
    179 bool CryptoKey::parseFormat(const String& formatString, WebCryptoKeyFormat& format, CryptoResult* result)
    180 {
    181     // There are few enough values that testing serially is fast enough.
    182     if (formatString == "raw") {
    183         format = WebCryptoKeyFormatRaw;
    184         return true;
    185     }
    186     if (formatString == "pkcs8") {
    187         format = WebCryptoKeyFormatPkcs8;
    188         return true;
    189     }
    190     if (formatString == "spki") {
    191         format = WebCryptoKeyFormatSpki;
    192         return true;
    193     }
    194     if (formatString == "jwk") {
    195         format = WebCryptoKeyFormatJwk;
    196         return true;
    197     }
    198 
    199     result->completeWithError(WebCryptoErrorTypeSyntax, "Invalid keyFormat argument");
    200     return false;
    201 }
    202 
    203 bool CryptoKey::parseUsageMask(const Vector<String>& usages, WebCryptoKeyUsageMask& mask, CryptoResult* result)
    204 {
    205     mask = 0;
    206     for (size_t i = 0; i < usages.size(); ++i) {
    207         WebCryptoKeyUsageMask usage = keyUsageStringToMask(usages[i]);
    208         if (!usage) {
    209             result->completeWithError(WebCryptoErrorTypeSyntax, "Invalid keyUsages argument");
    210             return false;
    211         }
    212         mask |= usage;
    213     }
    214     return true;
    215 }
    216 
    217 } // namespace blink
    218