crypto: Add ed25519 implementation from OpenSSH.

Reviewed-by: Andreas Schneider <asn@cryptomilk.org>

1 files changed, 79 insertions, 0 deletions

diff --git a/include/libssh/ed25519.h b/include/libssh/ed25519.h
new file mode 100644
index 00000000..7b48856c
--- /dev/null
+++ b/include/libssh/ed25519.h
@@ -0,0 +1,79 @@
+/*
+ * This file is part of the SSH Library
+ *
+ * Copyright (c) 2014 by Aris Adamantiadis
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#ifndef ED25519_H_
+#define ED25519_H_
+#include "libssh/priv.h"
+
+/**
+ * @defgroup ed25519 ed25519 API
+ * @internal
+ * @brief API for DJB's ed25519
+ *
+ * @{ */
+
+#define ED25519_PK_LEN 32
+#define ED25519_SK_LEN 64
+#define ED25519_SIG_LEN 64
+
+typedef uint8_t ed25519_pubkey[ED25519_PK_LEN];
+typedef uint8_t ed25519_privkey[ED25519_SK_LEN];
+typedef uint8_t ed25519_signature[ED25519_SIG_LEN];
+
+/** @internal
+ * @brief generate an ed25519 key pair
+ * @param[out] pk generated public key
+ * @param[out] sk generated secret key
+ * @return     0 on success, -1 on error.
+ * */
+int crypto_sign_ed25519_keypair(ed25519_pubkey pk, ed25519_privkey sk);
+
+/** @internal
+ * @brief sign a message with ed25519
+ * @param[out] sm location to store the signed message.
+ *                Its length should be mlen + 64.
+ * @param[out] smlen pointer to the size of the signed message
+ * @param[in] m message to be signed
+ * @param[in] mlen length of the message to be signed
+ * @param[in] sk secret key to sign the message with
+ * @return    0 on success.
+ */
+int crypto_sign_ed25519(
+    unsigned char *sm,unsigned long long *smlen,
+    const unsigned char *m,unsigned long long mlen,
+    const ed25519_privkey sk);
+
+/** @internal
+ * @brief "open" and verify the signature of a signed message
+ * @param[out] m location to store the verified message.
+ *               Its length should be equal to smlen.
+ * @param[out] mlen pointer to the size of the verified message
+ * @param[in] sm signed message to verify
+ * @param[in] smlen length of the signed message to verify
+ * @param[in] pk public key used to sign the message
+ * @returns   0 on success (supposedly).
+ */
+int crypto_sign_ed25519_open(
+    unsigned char *m,unsigned long long *mlen,
+    const unsigned char *sm,unsigned long long smlen,
+    const ed25519_pubkey pk);
+
+/** @} */
+#endif /* ED25519_H_ */