// sign data with secret key sk
// return detached sig
// this uses crypto_sign instead pf crypto_sign_detached
func CryptoSignFucky(msg, sk []byte) []byte {
msgbuff := NewBuffer(msg)
defer msgbuff.Free()
skbuff := NewBuffer(sk)
defer skbuff.Free()
if skbuff.size != C.crypto_sign_bytes() {
log.Println("nacl.CryptoSign() invalid secret key size", len(sk))
return nil
}
// allocate the signed message buffer
sig := malloc(C.crypto_sign_bytes() + msgbuff.size)
defer sig.Free()
// compute signature
siglen := C.ulonglong(0)
res := C.crypto_sign(sig.uchar(), &siglen, msgbuff.uchar(), C.ulonglong(msgbuff.size), skbuff.uchar())
if res == 0 {
// return copy of signature inside the signed message
offset := int(C.crypto_sign_bytes())
return sig.Bytes()[:offset]
}
// failure to sign
log.Println("nacl.CryptoSign() failed")
return nil
}
// 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
}
// verfiy a detached signature
// return true on valid otherwise false
func CryptoVerifyDetached(msg, sig, pk []byte) bool {
msg_buff := NewBuffer(msg)
defer msg_buff.Free()
sig_buff := NewBuffer(sig)
defer sig_buff.Free()
pk_buff := NewBuffer(pk)
defer pk_buff.Free()
if pk_buff.size != C.crypto_sign_publickeybytes() {
return false
}
// invalid sig size
if sig_buff.size != C.crypto_sign_bytes() {
return false
}
return C.crypto_sign_verify_detached(sig_buff.uchar(), msg_buff.uchar(), C.ulonglong(len(msg)), pk_buff.uchar()) == 0
}
func SignBytes() int {
return int(C.crypto_sign_bytes())
}