1 files changed, 96 insertions, 1 deletions
diff --git a/c_src/monocypher_nif.c b/c_src/monocypher_nif.c
index 209dd66..7e25d90 100644
--- a/c_src/monocypher_nif.c
+++ b/c_src/monocypher_nif.c
@@ -4,6 +4,7 @@
 
 #include <erl_nif.h>
 #include "monocypher.h"
+#include "monocypher-ed25519.h"
 
 /* Authenticated Encryption */
 
@@ -237,6 +238,97 @@ static ERL_NIF_TERM crypto_ietf_chacha20_ctr_nif(ErlNifEnv* env, int argc, const
 }
 
 
+/* Public Key Signature (Ed25519) */
+
+static ERL_NIF_TERM crypto_ed25519_public_key_nif(ErlNifEnv* env, int argc, const ERL_NIF_TERM argv[])
+{
+
+    ErlNifBinary secret_key;
+    if(!enif_inspect_binary(env, argv[0], &secret_key)) {
+        return enif_make_badarg(env);
+    }
+
+    if(secret_key.size != 32) {
+        return enif_make_badarg(env);
+    }
+
+    ERL_NIF_TERM public_key_term;
+    unsigned char* public_key = enif_make_new_binary(env, 32, &public_key_term);
+
+    crypto_ed25519_public_key(public_key, secret_key.data);
+
+    return public_key_term;
+}
+
+static ERL_NIF_TERM crypto_ed25519_sign_nif(ErlNifEnv* env, int argc, const ERL_NIF_TERM argv[])
+{
+
+    ErlNifBinary secret_key;
+    if(!enif_inspect_binary(env, argv[0], &secret_key)) {
+        return enif_make_badarg(env);
+    }
+
+    if(secret_key.size != 32) {
+        return enif_make_badarg(env);
+    }
+    
+    ErlNifBinary public_key;
+    if(!enif_inspect_binary(env, argv[1], &public_key)) {
+        return enif_make_badarg(env);
+    }
+
+    if(public_key.size != 32) {
+        return enif_make_badarg(env);
+    }
+
+    ErlNifBinary message;
+    if(!enif_inspect_binary(env, argv[2], &message)) {
+        return enif_make_badarg(env);
+    }
+
+    ERL_NIF_TERM signature_term;
+    unsigned char* signature = enif_make_new_binary(env, 64, &signature_term);
+
+    crypto_ed25519_sign(signature, secret_key.data, public_key.data, message.data, message.size);
+    
+    return signature_term;
+}
+
+static ERL_NIF_TERM crypto_ed25519_check_nif(ErlNifEnv* env, int argc, const ERL_NIF_TERM argv[])
+{
+    ErlNifBinary signature;
+    if(!enif_inspect_binary(env, argv[0], &signature)) {
+        return enif_make_badarg(env);
+    }
+
+    if(signature.size != 64) {
+        return enif_make_badarg(env);
+    }
+    
+    ErlNifBinary public_key;
+    if(!enif_inspect_binary(env, argv[1], &public_key)) {
+        return enif_make_badarg(env);
+    }
+
+    if(public_key.size != 32) {
+        return enif_make_badarg(env);
+    }
+
+    ErlNifBinary message;
+    if(!enif_inspect_binary(env, argv[2], &message)) {
+        return enif_make_badarg(env);
+    }
+
+    int check_return_value = crypto_ed25519_check(signature.data, public_key.data, message.data, message.size);
+
+    if (check_return_value == 0) {
+        return enif_make_atom_len(env, "ok", 2);
+    } else {
+        return enif_make_atom_len(env, "forgery", 7);
+    }
+}
+
+
 static ErlNifFunc nif_funs[] =
 {
     {"crypto_lock", 4, crypto_lock_nif},
@@ -244,7 +336,10 @@ static ErlNifFunc nif_funs[] =
     {"crypto_blake2b", 1, crypto_blake2b_nif},
     {"crypto_blake2b_general", 3, crypto_blake2b_general_nif},
     {"crypto_ietf_chacha20", 3, crypto_ietf_chacha20_nif},
-    {"crypto_ietf_chacha20_ctr", 4, crypto_ietf_chacha20_ctr_nif}
+    {"crypto_ietf_chacha20_ctr", 4, crypto_ietf_chacha20_ctr_nif},
+    {"crypto_ed25519_public_key", 1, crypto_ed25519_public_key_nif},
+    {"crypto_ed25519_sign", 3, crypto_ed25519_sign_nif},
+    {"crypto_ed25519_check", 3, crypto_ed25519_check_nif}
 };
 
 ERL_NIF_INIT(monocypher, nif_funs, NULL, NULL, NULL, NULL);