xref: /aosp_15_r20/external/tink/cc/subtle/prf/streaming_prf.h (revision e7b1675dde1b92d52ec075b0a92829627f2c52a5)
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 #ifndef TINK_SUBTLE_PRF_STREAMING_PRF_H_
17 #define TINK_SUBTLE_PRF_STREAMING_PRF_H_
18 
19 #include <memory>
20 
21 #include "absl/strings/string_view.h"
22 #include "tink/input_stream.h"
23 
24 namespace crypto {
25 namespace tink {
26 
27 ///////////////////////////////////////////////////////////////////////////////
28 // Streaming API interface for PseudoRandomFunctions.
29 //
30 // Implementations of this are indistinguishable from true random functions.
31 //
32 // For a formal description of the security properties, see the documentation in
33 // the corresponding Java class.
34 class StreamingPrf {
35  public:
36   // Returns a stream of pseudorandom bytes for this input. Calling Get twice
37   // with the same input will return a copy of the same input stream.
38   virtual std::unique_ptr<InputStream> ComputePrf(
39       absl::string_view input) const = 0;
40 
41   virtual ~StreamingPrf() = default;
42 };
43 
44 }  // namespace tink
45 }  // namespace crypto
46 
47 #endif  // TINK_SUBTLE_PRF_STREAMING_PRF_H_
48