1/*
2 * Copyright (C) 2017 Apple Inc. All rights reserved.
3 * Copyright (C) 2017 Metrological Group B.V.
4 * Copyright (C) 2017 Igalia S.L.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS''
16 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
17 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
18 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS
19 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
20 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
21 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
22 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
23 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
24 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
25 * THE POSSIBILITY OF SUCH DAMAGE.
26 */
27
28#include "config.h"
29#include "CryptoAlgorithmRSA_PSS.h"
30
31#if ENABLE(WEB_CRYPTO)
32
33#include "CryptoAlgorithmRsaPssParams.h"
34#include "CryptoKeyRSA.h"
35#include "GCryptUtilities.h"
36
37namespace WebCore {
38
39static Optional<Vector<uint8_t>> gcryptSign(gcry_sexp_t keySexp, const Vector<uint8_t>& data, CryptoAlgorithmIdentifier hashAlgorithmIdentifier, size_t saltLength, size_t keySizeInBytes)
40{
41 // Perform digest operation with the specified algorithm on the given data.
42 Vector<uint8_t> dataHash;
43 {
44 auto digestAlgorithm = hashCryptoDigestAlgorithm(hashAlgorithmIdentifier);
45 if (!digestAlgorithm)
46 return WTF::nullopt;
47
48 auto digest = PAL::CryptoDigest::create(*digestAlgorithm);
49 if (!digest)
50 return WTF::nullopt;
51
52 digest->addBytes(data.data(), data.size());
53 dataHash = digest->computeHash();
54 }
55
56 // Construct the `data` s-expression that contains PSS-padded hashed data.
57 PAL::GCrypt::Handle<gcry_sexp_t> dataSexp;
58 {
59 auto shaAlgorithm = hashAlgorithmName(hashAlgorithmIdentifier);
60 if (!shaAlgorithm)
61 return WTF::nullopt;
62
63 gcry_error_t error = gcry_sexp_build(&dataSexp, nullptr, "(data(flags pss)(salt-length %u)(hash %s %b))",
64 saltLength, *shaAlgorithm, dataHash.size(), dataHash.data());
65 if (error != GPG_ERR_NO_ERROR) {
66 PAL::GCrypt::logError(error);
67 return WTF::nullopt;
68 }
69 }
70
71 // Perform the PK signing, retrieving a `sig-val` s-expression of the following form:
72 // (sig-val
73 // (rsa
74 // (s s-mpi)))
75 PAL::GCrypt::Handle<gcry_sexp_t> signatureSexp;
76 gcry_error_t error = gcry_pk_sign(&signatureSexp, dataSexp, keySexp);
77 if (error != GPG_ERR_NO_ERROR) {
78 PAL::GCrypt::logError(error);
79 return WTF::nullopt;
80 }
81
82 // Retrieve MPI data of the embedded `s` integer.
83 PAL::GCrypt::Handle<gcry_sexp_t> sSexp(gcry_sexp_find_token(signatureSexp, "s", 0));
84 if (!sSexp)
85 return WTF::nullopt;
86
87 return mpiZeroPrefixedData(sSexp, keySizeInBytes);
88}
89
90static Optional<bool> gcryptVerify(gcry_sexp_t keySexp, const Vector<uint8_t>& signature, const Vector<uint8_t>& data, CryptoAlgorithmIdentifier hashAlgorithmIdentifier, size_t saltLength)
91{
92 // Perform digest operation with the specified algorithm on the given data.
93 Vector<uint8_t> dataHash;
94 {
95 auto digestAlgorithm = hashCryptoDigestAlgorithm(hashAlgorithmIdentifier);
96 if (!digestAlgorithm)
97 return WTF::nullopt;
98
99 auto digest = PAL::CryptoDigest::create(*digestAlgorithm);
100 if (!digest)
101 return WTF::nullopt;
102
103 digest->addBytes(data.data(), data.size());
104 dataHash = digest->computeHash();
105 }
106
107 // Construct the `sig-val` s-expression that contains the signature data.
108 PAL::GCrypt::Handle<gcry_sexp_t> signatureSexp;
109 gcry_error_t error = gcry_sexp_build(&signatureSexp, nullptr, "(sig-val(rsa(s %b)))",
110 signature.size(), signature.data());
111 if (error != GPG_ERR_NO_ERROR) {
112 PAL::GCrypt::logError(error);
113 return WTF::nullopt;
114 }
115
116 // Construct the `data` s-expression that contains PSS-padded hashed data.
117 PAL::GCrypt::Handle<gcry_sexp_t> dataSexp;
118 {
119 auto shaAlgorithm = hashAlgorithmName(hashAlgorithmIdentifier);
120 if (!shaAlgorithm)
121 return WTF::nullopt;
122
123 error = gcry_sexp_build(&dataSexp, nullptr, "(data(flags pss)(salt-length %u)(hash %s %b))",
124 saltLength, *shaAlgorithm, dataHash.size(), dataHash.data());
125 if (error != GPG_ERR_NO_ERROR) {
126 PAL::GCrypt::logError(error);
127 return WTF::nullopt;
128 }
129 }
130
131 // Perform the PK verification. We report success if there's no error returned, or
132 // a failure in any other case. OperationError should not be returned at this point,
133 // avoiding spilling information about the exact cause of verification failure.
134 error = gcry_pk_verify(signatureSexp, dataSexp, keySexp);
135 return { error == GPG_ERR_NO_ERROR };
136}
137
138ExceptionOr<Vector<uint8_t>> CryptoAlgorithmRSA_PSS::platformSign(const CryptoAlgorithmRsaPssParams& parameters, const CryptoKeyRSA& key, const Vector<uint8_t>& data)
139{
140 RELEASE_ASSERT_WITH_SECURITY_IMPLICATION(!(key.keySizeInBits() % 8));
141 auto output = gcryptSign(key.platformKey(), data, key.hashAlgorithmIdentifier(), parameters.saltLength, key.keySizeInBits() / 8);
142 if (!output)
143 return Exception { OperationError };
144 return WTFMove(*output);
145}
146
147ExceptionOr<bool> CryptoAlgorithmRSA_PSS::platformVerify(const CryptoAlgorithmRsaPssParams& parameters, const CryptoKeyRSA& key, const Vector<uint8_t>& signature, const Vector<uint8_t>& data)
148{
149 auto output = gcryptVerify(key.platformKey(), signature, data, key.hashAlgorithmIdentifier(), parameters.saltLength);
150 if (!output)
151 return Exception { OperationError };
152 return WTFMove(*output);
153}
154
155
156} // namespace WebCore
157
158#endif // ENABLE(WEB_CRYPTO)
159