1/*
2 * Copyright (C) 2017 Apple 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
6 * are met:
7 * 1. Redistributions of source code must retain the above copyright
8 * notice, this list of conditions and the following disclaimer.
9 * 2. Redistributions in binary form must reproduce the above copyright
10 * notice, this list of conditions and the following disclaimer in the
11 * documentation and/or other materials provided with the distribution.
12 *
13 * THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS''
14 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
15 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
16 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS
17 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
18 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
19 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
20 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
21 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
22 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
23 * THE POSSIBILITY OF SUCH DAMAGE.
24 */
25
26#include "config.h"
27#include "ResourceCryptographicDigest.h"
28
29#include "ParsingUtilities.h"
30#include <pal/crypto/CryptoDigest.h>
31#include <wtf/Optional.h>
32#include <wtf/text/Base64.h>
33
34namespace WebCore {
35
36template<typename CharacterType>
37static bool parseHashAlgorithmAdvancingPosition(const CharacterType*& position, const CharacterType* end, ResourceCryptographicDigest::Algorithm& algorithm)
38{
39 // FIXME: This would be much cleaner with a lookup table of pairs of label / algorithm enum values, but I can't
40 // figure out how to keep the labels compiletime strings for skipExactlyIgnoringASCIICase.
41
42 if (skipExactlyIgnoringASCIICase(position, end, "sha256")) {
43 algorithm = ResourceCryptographicDigest::Algorithm::SHA256;
44 return true;
45 }
46 if (skipExactlyIgnoringASCIICase(position, end, "sha384")) {
47 algorithm = ResourceCryptographicDigest::Algorithm::SHA384;
48 return true;
49 }
50 if (skipExactlyIgnoringASCIICase(position, end, "sha512")) {
51 algorithm = ResourceCryptographicDigest::Algorithm::SHA512;
52 return true;
53 }
54
55 return false;
56}
57
58template<typename CharacterType>
59static Optional<ResourceCryptographicDigest> parseCryptographicDigestImpl(const CharacterType*& position, const CharacterType* end)
60{
61 if (position == end)
62 return WTF::nullopt;
63
64 ResourceCryptographicDigest::Algorithm algorithm;
65 if (!parseHashAlgorithmAdvancingPosition(position, end, algorithm))
66 return WTF::nullopt;
67
68 if (!skipExactly<CharacterType>(position, end, '-'))
69 return WTF::nullopt;
70
71 const CharacterType* beginHashValue = position;
72 skipWhile<CharacterType, isBase64OrBase64URLCharacter>(position, end);
73 skipExactly<CharacterType>(position, end, '=');
74 skipExactly<CharacterType>(position, end, '=');
75
76 if (position == beginHashValue)
77 return WTF::nullopt;
78
79 Vector<uint8_t> digest;
80 StringView hashValue(beginHashValue, position - beginHashValue);
81 if (!base64Decode(hashValue, digest, Base64ValidatePadding)) {
82 if (!base64URLDecode(hashValue, digest))
83 return WTF::nullopt;
84 }
85
86 return ResourceCryptographicDigest { algorithm, WTFMove(digest) };
87}
88
89Optional<ResourceCryptographicDigest> parseCryptographicDigest(const UChar*& begin, const UChar* end)
90{
91 return parseCryptographicDigestImpl(begin, end);
92}
93
94Optional<ResourceCryptographicDigest> parseCryptographicDigest(const LChar*& begin, const LChar* end)
95{
96 return parseCryptographicDigestImpl(begin, end);
97}
98
99template<typename CharacterType>
100static Optional<EncodedResourceCryptographicDigest> parseEncodedCryptographicDigestImpl(const CharacterType*& position, const CharacterType* end)
101{
102 if (position == end)
103 return WTF::nullopt;
104
105 EncodedResourceCryptographicDigest::Algorithm algorithm;
106 if (!parseHashAlgorithmAdvancingPosition(position, end, algorithm))
107 return WTF::nullopt;
108
109 if (!skipExactly<CharacterType>(position, end, '-'))
110 return WTF::nullopt;
111
112 const CharacterType* beginHashValue = position;
113 skipWhile<CharacterType, isBase64OrBase64URLCharacter>(position, end);
114 skipExactly<CharacterType>(position, end, '=');
115 skipExactly<CharacterType>(position, end, '=');
116
117 if (position == beginHashValue)
118 return WTF::nullopt;
119
120 return EncodedResourceCryptographicDigest { algorithm, String(beginHashValue, position - beginHashValue) };
121}
122
123Optional<EncodedResourceCryptographicDigest> parseEncodedCryptographicDigest(const UChar*& begin, const UChar* end)
124{
125 return parseEncodedCryptographicDigestImpl(begin, end);
126}
127
128Optional<EncodedResourceCryptographicDigest> parseEncodedCryptographicDigest(const LChar*& begin, const LChar* end)
129{
130 return parseEncodedCryptographicDigestImpl(begin, end);
131}
132
133Optional<ResourceCryptographicDigest> decodeEncodedResourceCryptographicDigest(const EncodedResourceCryptographicDigest& encodedDigest)
134{
135 Vector<uint8_t> digest;
136 if (!base64Decode(encodedDigest.digest, digest, Base64ValidatePadding)) {
137 if (!base64URLDecode(encodedDigest.digest, digest))
138 return WTF::nullopt;
139 }
140
141 return ResourceCryptographicDigest { encodedDigest.algorithm, WTFMove(digest) };
142}
143
144static PAL::CryptoDigest::Algorithm toCryptoDigestAlgorithm(ResourceCryptographicDigest::Algorithm algorithm)
145{
146 switch (algorithm) {
147 case ResourceCryptographicDigest::Algorithm::SHA256:
148 return PAL::CryptoDigest::Algorithm::SHA_256;
149 case ResourceCryptographicDigest::Algorithm::SHA384:
150 return PAL::CryptoDigest::Algorithm::SHA_384;
151 case ResourceCryptographicDigest::Algorithm::SHA512:
152 return PAL::CryptoDigest::Algorithm::SHA_512;
153 }
154 ASSERT_NOT_REACHED();
155 return PAL::CryptoDigest::Algorithm::SHA_512;
156}
157
158ResourceCryptographicDigest cryptographicDigestForBytes(ResourceCryptographicDigest::Algorithm algorithm, const void* bytes, size_t length)
159{
160 auto cryptoDigest = PAL::CryptoDigest::create(toCryptoDigestAlgorithm(algorithm));
161 cryptoDigest->addBytes(bytes, length);
162 return { algorithm, cryptoDigest->computeHash() };
163}
164
165}
166