1 /* 2 * Copyright 2018 Google LLC 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * https://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 #ifndef FCP_SECAGG_SHARED_PRNG_H_ 18 #define FCP_SECAGG_SHARED_PRNG_H_ 19 20 #include <cstdint> 21 #include <vector> 22 23 namespace fcp { 24 namespace secagg { 25 26 // An interface for a secure pseudo-random number generator. 27 class SecurePrng { 28 public: 29 virtual uint8_t Rand8() = 0; 30 virtual uint64_t Rand64() = 0; 31 virtual ~SecurePrng() = default; 32 }; 33 34 // Extension of SecurePrng interface that supports batch mode - getting multiple 35 // pseudo-random numbers in a single call. 36 class SecureBatchPrng : public SecurePrng { 37 public: 38 // Get the maximum size of a buffer that can be filled by RandBuffer() in a 39 // single call. 40 virtual size_t GetMaxBufferSize() const = 0; 41 42 // Fills the provided buffer with pseudorandom bytes. Returns the number of 43 // bytes that has been generated, which can be smaller than the requested 44 // buffer_size if it exceeds the maximum buffer size. 45 virtual int RandBuffer(uint8_t* buffer, int buffer_size) = 0; 46 }; 47 48 } // namespace secagg 49 } // namespace fcp 50 51 #endif // FCP_SECAGG_SHARED_PRNG_H_ 52