1 // Copyright 2019 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/util/input_stream_util.h"
18
19 #include <algorithm>
20 #include <string>
21
22 #include "absl/algorithm/container.h"
23 #include "absl/strings/str_cat.h"
24 #include "absl/types/span.h"
25 #include "tink/input_stream.h"
26 #include "tink/util/statusor.h"
27
28 namespace crypto {
29 namespace tink {
30
31 namespace {
32 template <typename Result>
ReadBytesFromStreamImpl(int num_bytes,InputStream * input_stream)33 util::StatusOr<Result> ReadBytesFromStreamImpl(int num_bytes,
34 InputStream* input_stream) {
35 const void* buffer;
36 Result result;
37 if (num_bytes > 0) {
38 result.resize(num_bytes);
39 }
40 int num_bytes_read = 0;
41
42 while (num_bytes_read < num_bytes) {
43 auto next_result = input_stream->Next(&buffer);
44 if (!next_result.ok()) return next_result.status();
45
46 int num_bytes_in_chunk = next_result.value();
47 int num_bytes_to_copy =
48 std::min(num_bytes - num_bytes_read, num_bytes_in_chunk);
49 absl::c_copy(absl::MakeSpan(reinterpret_cast<const char*>(buffer),
50 num_bytes_to_copy),
51 result.begin() + num_bytes_read);
52 input_stream->BackUp(num_bytes_in_chunk - num_bytes_to_copy);
53 num_bytes_read += num_bytes_to_copy;
54 }
55 return result;
56 }
57 } // namespace
58
ReadBytesFromStream(int num_bytes,InputStream * input_stream)59 util::StatusOr<std::string> ReadBytesFromStream(int num_bytes,
60 InputStream* input_stream) {
61 return ReadBytesFromStreamImpl<std::string>(num_bytes, input_stream);
62 }
63
ReadSecretBytesFromStream(int num_bytes,InputStream * input_stream)64 util::StatusOr<util::SecretData> ReadSecretBytesFromStream(
65 int num_bytes, InputStream* input_stream) {
66 return ReadBytesFromStreamImpl<util::SecretData>(num_bytes, input_stream);
67 }
68
69 } // namespace tink
70 } // namespace crypto
71