| // Copyright 2021 The Pigweed Authors |
| // |
| // Licensed under the Apache License, Version 2.0 (the "License"); you may not |
| // use this file except in compliance with the License. You may obtain a copy of |
| // the License at |
| // |
| // https://www.apache.org/licenses/LICENSE-2.0 |
| // |
| // Unless required by applicable law or agreed to in writing, software |
| // distributed under the License is distributed on an "AS IS" BASIS, WITHOUT |
| // WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the |
| // License for the specific language governing permissions and limitations under |
| // the License. |
| |
| #pragma once |
| |
| #include <cstdint> |
| |
| #include "pw_bytes/span.h" |
| #include "pw_crypto/sha256_backend.h" |
| #include "pw_status/status.h" |
| |
| namespace pw::crypto::sha256 { |
| |
| // Size in bytes of a SHA256 digest. |
| constexpr uint32_t kDigestSizeBytes = 32; |
| |
| // Sha256 computes the SHA256 digest of potentially long, non-contiguous input |
| // messages. |
| class Sha256 { |
| public: |
| Sha256(); |
| // Remove copy/move ctors |
| Sha256(const Sha256& other) = delete; |
| Sha256(Sha256&& other) = delete; |
| Sha256& operator=(const Sha256& other) = delete; |
| Sha256& operator=(Sha256&& other) = delete; |
| |
| // Update adds `data` to the running hasher. |
| void Update(ConstByteSpan data); |
| |
| // Final outputs the digest in `out_digest` and resets the hasher state. |
| // `out_digest` must be at least `kDigestSizeBytes` long. |
| Status Final(ByteSpan out_digest); |
| |
| private: |
| backend::Sha256Context ctx_; |
| }; |
| |
| // Digest calculates the SHA256 digest of `message` and stores the result |
| // in `out_digest`. `out_digest` must be at least `kDigestSizeBytes` long. |
| inline Status Digest(ConstByteSpan message, ByteSpan out_digest) { |
| Sha256 h; |
| h.Update(message); |
| return h.Final(out_digest); |
| } |
| |
| } // namespace pw::crypto::sha256 |