forked from NebulousLabs/Sia
/
signatures.go
57 lines (48 loc) · 1.27 KB
/
signatures.go
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package crypto
import (
"crypto/rand"
"errors"
"github.com/agl/ed25519"
)
const (
PublicKeySize = ed25519.PublicKeySize
SecretKeySize = ed25519.PrivateKeySize
SignatureSize = ed25519.SignatureSize
)
type (
PublicKey [ed25519.PublicKeySize]byte
SecretKey [ed25519.PrivateKeySize]byte
Signature [ed25519.SignatureSize]byte
)
var (
ErrNilInput = errors.New("cannot use nil input")
ErrInvalidSignature = errors.New("invalid signature")
)
// GenerateKeyPair creates a public-secret keypair that can be used to sign and
// verify messages.
func GenerateSignatureKeys() (sk SecretKey, pk PublicKey, err error) {
pkPointer, skPointer, err := ed25519.GenerateKey(rand.Reader)
if err != nil {
return
}
sk = *skPointer
pk = *pkPointer
return
}
// SignHash signs a message using a secret key.
func SignHash(data Hash, sk SecretKey) (sig Signature, err error) {
skNorm := [SecretKeySize]byte(sk)
sig = *ed25519.Sign(&skNorm, data[:])
return
}
// VerifyHash uses a public key and input data to verify a signature.
func VerifyHash(data Hash, pk PublicKey, sig Signature) (err error) {
pkNorm := [PublicKeySize]byte(pk)
sigNorm := [SignatureSize]byte(sig)
verifies := ed25519.Verify(&pkNorm, data[:], &sigNorm)
if !verifies {
err = ErrInvalidSignature
return
}
return
}