1 // Copyright 2021 Google LLC
2 //
3 // Licensed under the Apache License, Version 2.0 (the "License");
4 // you may not use this file except in compliance with the License.
5 // You may obtain a copy of the License at
6 //
7 // http://www.apache.org/licenses/LICENSE-2.0
8 //
9 // Unless required by applicable law or agreed to in writing, software
10 // distributed under the License is distributed on an "AS IS" BASIS,
11 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12 // See the License for the specific language governing permissions and
13 // limitations under the License.
14 //
15 ///////////////////////////////////////////////////////////////////////////////
16
17 #include "tink/experimental/pqcrypto/signature/subtle/falcon_verify.h"
18
19 #include <memory>
20 #include <string>
21 #include <utility>
22
23 #include "absl/memory/memory.h"
24 #include "absl/status/status.h"
25 #include "absl/strings/str_format.h"
26 #include "tink/experimental/pqcrypto/signature/subtle/falcon_subtle_utils.h"
27 #include "tink/util/secret_data.h"
28 #include "tink/util/statusor.h"
29
30 extern "C" {
31 #include "third_party/pqclean/crypto_sign/falcon-1024/api.h"
32 #include "third_party/pqclean/crypto_sign/falcon-512/api.h"
33 }
34
35 namespace crypto {
36 namespace tink {
37 namespace subtle {
38
39 // static
New(const FalconPublicKeyPqclean & public_key)40 util::StatusOr<std::unique_ptr<PublicKeyVerify>> FalconVerify::New(
41 const FalconPublicKeyPqclean& public_key) {
42 auto status = internal::CheckFipsCompatibility<FalconVerify>();
43 if (!status.ok()) return status;
44
45 return {
46 absl::WrapUnique<FalconVerify>(new FalconVerify(public_key))};
47 }
48
Verify(absl::string_view signature,absl::string_view data) const49 util::Status FalconVerify::Verify(absl::string_view signature,
50 absl::string_view data) const {
51 int32_t key_size = public_key_.GetKey().size();
52 int result = 1;
53
54 switch (key_size) {
55 case kFalcon512PublicKeySize: {
56 result = PQCLEAN_FALCON512_crypto_sign_verify(
57 reinterpret_cast<const uint8_t *>(signature.data()), signature.size(),
58 reinterpret_cast<const uint8_t *>(data.data()), data.size(),
59 reinterpret_cast<const uint8_t *>(public_key_.GetKey().data()));
60 break;
61 }
62 case kFalcon1024PublicKeySize: {
63 result = PQCLEAN_FALCON1024_crypto_sign_verify(
64 reinterpret_cast<const uint8_t *>(signature.data()), signature.size(),
65 reinterpret_cast<const uint8_t *>(data.data()), data.size(),
66 reinterpret_cast<const uint8_t *>(public_key_.GetKey().data()));
67 break;
68 }
69 default:
70 return util::Status(absl::StatusCode::kInvalidArgument,
71 "Invalid keysize.");
72 }
73
74 if (result != 0) {
75 return util::Status(absl::StatusCode::kInternal, "Signature is not valid.");
76 }
77
78 return util::OkStatus();
79 }
80
81 } // namespace subtle
82 } // namespace tink
83 } // namespace crypto
84