Initial

romulus_m.go

@@ -0,0 +1,80 @@
+package romulus_go
+
+import (
+	"crypto/rand"
+	"errors"
+)
+
+const abytes int = 16
+const keysize int = 16
+const noncesize int = 16
+
+func Encrypt(key []byte, plaintext []byte, additionalData []byte) ([]byte, error) {
+
+	if len(key) < keysize {
+		return nil, errors.New("Failed to encrypt")
+	}
+
+	cipher := make([]byte, len(plaintext)+abytes+noncesize)
+	var cipherlen uint64 = (uint64)(len(cipher))
+	nonce := genNonce()
+	ret := romulus_m_encrypt(
+		cipher[noncesize:],
+		&cipherlen,
+		plaintext,
+		(uint64)(len(plaintext)),
+		additionalData,
+		(uint64)(len(additionalData)),
+		nil,
+		nonce,
+		key[:keysize],
+	)
+
+	if ret != 0 {
+		return nil, errors.New("Failed to encrypt")
+	}
+	copy(cipher, nonce)
+	return cipher[:(int)(cipherlen)+noncesize], nil
+}
+
+func Decrypt(key []byte, ciphertext []byte, additionalData []byte) (plaintext []byte, auth bool, err error) {
+
+	if len(ciphertext) <= noncesize || len(key) < keysize {
+		return nil, false, errors.New("Failed to decrypt")
+	}
+
+	defer func() {
+		if r := recover(); r != nil {
+			err = errors.New("Recovered from panic in decrypt")
+			auth = false
+		}
+	}()
+
+	plaintext = make([]byte, len(ciphertext))
+	var plaintextLen uint64 = (uint64)(len(plaintext))
+	ret := romulus_m_decrypt(
+		plaintext,
+		&plaintextLen,
+		nil,
+		ciphertext[noncesize:],
+		(uint64)(len(ciphertext)-noncesize),
+		additionalData,
+		(uint64)(len(additionalData)),
+		ciphertext[:noncesize],
+		key[:keysize],
+	)
+
+	if ret == -1 {
+		return nil, false, errors.New("Failed to authenticate")
+	} else if ret != 0 {
+		return nil, false, errors.New("Failed to decrypt")
+	}
+
+	return plaintext[:plaintextLen], true, nil
+}
+
+func genNonce() []byte {
+	buf := make([]byte, noncesize)
+	rand.Read(buf)
+	return buf
+}