diff options
Diffstat (limited to 'internal/protocol/hmac.go')
| -rw-r--r-- | internal/protocol/hmac.go | 31 | +31 −0 |
1 files changed, 31 insertions, 0 deletions
diff --git a/internal/protocol/hmac.go b/internal/protocol/hmac.go new file mode 100644 --- /dev/null +++ b/internal/protocol/hmac.go @@ -0,0 +1,31 @@ +// Copyright (c) 2026 Nikolay Govorov +// SPDX-License-Identifier: AGPL-3.0-or-later + +package protocol + +import ( + "crypto/hmac" + "crypto/rand" + "crypto/sha256" +) + +const NonceSize = 32 + +func GenerateNonce() ([]byte, error) { + nonce := make([]byte, NonceSize) + _, err := rand.Read(nonce) + return nonce, err +} + +// ComputeProof returns HMAC-SHA256(secret, first || second). +func ComputeProof(secret, first, second []byte) []byte { + mac := hmac.New(sha256.New, secret) + mac.Write(first) + mac.Write(second) + return mac.Sum(nil) +} + +func VerifyProof(secret, first, second, proof []byte) bool { + expected := ComputeProof(secret, first, second) + return hmac.Equal(expected, proof) +} |