// encrypts a message to a user given their public key is known
// returns an encrypted box
func CryptoBox(msg, nounce, pk, sk []byte) []byte {
msgbuff := NewBuffer(msg)
defer msgbuff.Free()
// check sizes
if len(pk) != int(C.crypto_box_publickeybytes()) {
log.Println("len(pk) != crypto_box_publickey_bytes")
return nil
}
if len(sk) != int(C.crypto_box_secretkeybytes()) {
log.Println("len(sk) != crypto_box_secretkey_bytes")
return nil
}
if len(nounce) != int(C.crypto_box_macbytes()) {
log.Println("len(nounce) != crypto_box_macbytes()")
return nil
}
pkbuff := NewBuffer(pk)
defer pkbuff.Free()
skbuff := NewBuffer(sk)
defer skbuff.Free()
nouncebuff := NewBuffer(nounce)
defer nouncebuff.Free()
resultbuff := malloc(msgbuff.size + nouncebuff.size)
defer resultbuff.Free()
res := C.crypto_box_easy(resultbuff.uchar(), msgbuff.uchar(), C.ulonglong(msgbuff.size), nouncebuff.uchar(), pkbuff.uchar(), skbuff.uchar())
if res != 0 {
log.Println("crypto_box_easy failed:", res)
return nil
}
return resultbuff.Bytes()
}
// open an encrypted box
func CryptoBoxOpen(box, nounce, sk, pk []byte) ([]byte, error) {
boxbuff := NewBuffer(box)
defer boxbuff.Free()
// check sizes
if len(pk) != int(C.crypto_box_publickeybytes()) {
err := errors.New("len(pk) != crypto_box_publickey_bytes")
return nil, err
}
if len(sk) != int(C.crypto_box_secretkeybytes()) {
err := errors.New("len(sk) != crypto_box_secretkey_bytes")
return nil, err
}
if len(nounce) != int(C.crypto_box_macbytes()) {
err := errors.New("len(nounce) != crypto_box_macbytes()")
return nil, err
}
pkbuff := NewBuffer(pk)
defer pkbuff.Free()
skbuff := NewBuffer(sk)
defer skbuff.Free()
nouncebuff := NewBuffer(nounce)
defer nouncebuff.Free()
resultbuff := malloc(boxbuff.size - nouncebuff.size)
defer resultbuff.Free()
// decrypt
res := C.crypto_box_open_easy(resultbuff.uchar(), boxbuff.uchar(), C.ulonglong(boxbuff.size), nouncebuff.uchar(), pkbuff.uchar(), skbuff.uchar())
if res != 0 {
return nil, errors.New("crypto_box_open_easy failed")
}
// return result
return resultbuff.Bytes(), nil
}
func GenBoxKeypair() *KeyPair {
sk_len := C.crypto_box_secretkeybytes()
sk := malloc(sk_len)
pk_len := C.crypto_box_publickeybytes()
pk := malloc(pk_len)
res := C.crypto_box_keypair(pk.uchar(), sk.uchar())
if res == 0 {
return &KeyPair{pk, sk}
}
pk.Free()
sk.Free()
return nil
}
func GenBoxKeypair() *KeyPair {
sk_len := C.crypto_box_secretkeybytes()
sk := malloc(sk_len)
pk_len := C.crypto_box_publickeybytes()
pk := malloc(pk_len)
res := C.crypto_box_keypair(pk.uchar(), sk.uchar())
if res == 0 {
return &KeyPair{pk, sk}
}
log.Println("nacl.GenBoxKeyPair() failed to generate keypair")
pk.Free()
sk.Free()
return nil
}
// make keypair from seed
func SeedBoxKey(seed []byte) *KeyPair {
seed_len := C.crypto_box_seedbytes()
if C.size_t(len(seed)) != seed_len {
return nil
}
seedbuff := NewBuffer(seed)
defer seedbuff.Free()
pk_len := C.crypto_box_publickeybytes()
sk_len := C.crypto_box_secretkeybytes()
pkbuff := malloc(pk_len)
skbuff := malloc(sk_len)
res := C.crypto_box_seed_keypair(pkbuff.uchar(), skbuff.uchar(), seedbuff.uchar())
if res != 0 {
pkbuff.Free()
skbuff.Free()
return nil
}
return &KeyPair{pkbuff, skbuff}
}
// make keypair from seed
func SeedBoxKey(seed []byte) *KeyPair {
seed_len := C.crypto_box_seedbytes()
if C.size_t(len(seed)) != seed_len {
log.Println("nacl.SeedBoxKey() invalid seed size", len(seed))
return nil
}
seedbuff := NewBuffer(seed)
defer seedbuff.Free()
pk_len := C.crypto_box_publickeybytes()
sk_len := C.crypto_box_secretkeybytes()
pkbuff := malloc(pk_len)
skbuff := malloc(sk_len)
res := C.crypto_box_seed_keypair(pkbuff.uchar(), skbuff.uchar(), seedbuff.uchar())
if res != 0 {
pkbuff.Free()
skbuff.Free()
log.Println("nacl.SeedBoxKey cannot derive keys from seed:", res)
return nil
}
return &KeyPair{pkbuff, skbuff}
}
// BoxSecretKeyBytes returns the expected size, in bytes, of the secret keys for the box functions.
func BoxSecretKeyBytes() int {
return int(C.crypto_box_secretkeybytes())
}
// size of crypto_box private keys
func CryptoBoxPrivKeySize() int {
return int(C.crypto_box_secretkeybytes())
}