1 // Copyright 2013 The Chromium Authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
4
5 #include "net/quic/crypto/channel_id.h"
6
7 #include <openssl/bn.h>
8 #include <openssl/ec.h>
9 #include <openssl/ecdsa.h>
10 #include <openssl/obj_mac.h>
11 #include <openssl/sha.h>
12
13 #include "crypto/openssl_util.h"
14
15 using base::StringPiece;
16
17 namespace net {
18
19 // static
Verify(StringPiece key,StringPiece signed_data,StringPiece signature)20 bool ChannelIDVerifier::Verify(StringPiece key,
21 StringPiece signed_data,
22 StringPiece signature) {
23 return VerifyRaw(key, signed_data, signature, true);
24 }
25
26 // static
VerifyRaw(StringPiece key,StringPiece signed_data,StringPiece signature,bool is_channel_id_signature)27 bool ChannelIDVerifier::VerifyRaw(StringPiece key,
28 StringPiece signed_data,
29 StringPiece signature,
30 bool is_channel_id_signature) {
31 if (key.size() != 32 * 2 ||
32 signature.size() != 32 * 2) {
33 return false;
34 }
35
36 crypto::ScopedOpenSSL<EC_GROUP, EC_GROUP_free> p256(
37 EC_GROUP_new_by_curve_name(NID_X9_62_prime256v1));
38 if (p256.get() == NULL) {
39 return false;
40 }
41
42 crypto::ScopedOpenSSL<BIGNUM, BN_free> x(BN_new()), y(BN_new()),
43 r(BN_new()), s(BN_new());
44
45 ECDSA_SIG sig;
46 sig.r = r.get();
47 sig.s = s.get();
48
49 const uint8* key_bytes = reinterpret_cast<const uint8*>(key.data());
50 const uint8* signature_bytes =
51 reinterpret_cast<const uint8*>(signature.data());
52
53 if (BN_bin2bn(key_bytes + 0, 32, x.get()) == NULL ||
54 BN_bin2bn(key_bytes + 32, 32, y.get()) == NULL ||
55 BN_bin2bn(signature_bytes + 0, 32, sig.r) == NULL ||
56 BN_bin2bn(signature_bytes + 32, 32, sig.s) == NULL) {
57 return false;
58 }
59
60 crypto::ScopedOpenSSL<EC_POINT, EC_POINT_free> point(
61 EC_POINT_new(p256.get()));
62 if (point.get() == NULL ||
63 !EC_POINT_set_affine_coordinates_GFp(p256.get(), point.get(), x.get(),
64 y.get(), NULL)) {
65 return false;
66 }
67
68 crypto::ScopedOpenSSL<EC_KEY, EC_KEY_free> ecdsa_key(EC_KEY_new());
69 if (ecdsa_key.get() == NULL ||
70 !EC_KEY_set_group(ecdsa_key.get(), p256.get()) ||
71 !EC_KEY_set_public_key(ecdsa_key.get(), point.get())) {
72 return false;
73 }
74
75 SHA256_CTX sha256;
76 SHA256_Init(&sha256);
77 if (is_channel_id_signature) {
78 SHA256_Update(&sha256, kContextStr, strlen(kContextStr) + 1);
79 SHA256_Update(&sha256, kClientToServerStr, strlen(kClientToServerStr) + 1);
80 }
81 SHA256_Update(&sha256, signed_data.data(), signed_data.size());
82
83 unsigned char digest[SHA256_DIGEST_LENGTH];
84 SHA256_Final(digest, &sha256);
85
86 return ECDSA_do_verify(digest, sizeof(digest), &sig, ecdsa_key.get()) == 1;
87 }
88
89 } // namespace net
90