// Sign signs a message using the given EdDSA private key, returning the signature.
func (priv EdDSAPrivate) Sign(message []byte) []byte {
signature := make([]byte, EdDSASignatureLength)
rv := C.crypto_sign_detached(
(*C.uchar)(&signature[0]),
nil,
(*C.uchar)(&message[0]),
C.ulonglong(len(message)),
(*C.uchar)(&priv[0]))
if rv != 0 {
panic("crypto_sign_detached returned non-zero")
}
return signature
}
func CryptoSignDetached(m []byte, sk []byte) ([]byte, int) {
support.CheckSize(sk, CryptoSignSecretKeyBytes(), "secret key")
sig := make([]byte, CryptoSignBytes())
var actualSigSize C.ulonglong
exit := int(C.crypto_sign_detached(
(*C.uchar)(&sig[0]),
(&actualSigSize),
(*C.uchar)(&m[0]),
(C.ulonglong)(len(m)),
(*C.uchar)(&sk[0])))
return sig[:actualSigSize], exit
}
func (s *Ed25519Signer) SignHash(h []byte) (sig []byte, err error) {
var ch [32]C.uchar
for i, b := range h {
ch[i] = C.uchar(b)
}
var csig [32]C.uchar
var smlen_p C.ulonglong
res := C.crypto_sign_detached(&csig[0], &smlen_p, &ch[0], C.ulonglong(32), &s.k[0])
if res == 0 {
// success signing
sig = make([]byte, 32)
for i, b := range csig {
sig[i] = byte(b)
}
} else {
// failed signing
err = errors.New(fmt.Sprintf("failed to sign: crypto_sign_detached exit code %d", int(res)))
}
return
}
// sign data detached with secret key sk
func CryptoSignDetached(msg, sk []byte) []byte {
msgbuff := NewBuffer(msg)
defer msgbuff.Free()
skbuff := NewBuffer(sk)
defer skbuff.Free()
if skbuff.size != C.crypto_sign_bytes() {
return nil
}
// allocate the signature buffer
sig := malloc(C.crypto_sign_bytes())
defer sig.Free()
// compute signature
siglen := C.ulonglong(0)
res := C.crypto_sign_detached(sig.uchar(), &siglen, msgbuff.uchar(), C.ulonglong(msgbuff.size), skbuff.uchar())
if res == 0 && siglen == C.ulonglong(C.crypto_sign_bytes()) {
// return copy of signature buffer
return sig.Bytes()
}
// failure to sign
return nil
}
