From 8be433c9b65fe5f214151651055700d1fea02a56 Mon Sep 17 00:00:00 2001
From: default <nobody@localhost>
Date: Mon, 19 Sep 2022 22:58:27 +0200
Subject: [PATCH] New function hash_password() and check_password().

---
 main.c |  3 +++
 snac.c | 33 +++++++++++++++++++++++++++++++++
 snac.h |  3 +++
 3 files changed, 39 insertions(+)

diff --git a/main.c b/main.c
index ab4093b..ab83086 100644
--- a/main.c
+++ b/main.c
@@ -16,5 +16,8 @@ int main(int argc, char *argv[])
     snac_open(&snac, "mike");
     snac_log(&snac, xs_str_new("ok"));
 
+    char *passwd = xs_dict_get(snac.config, "passwd");
+    printf("%d\n", check_password("mike", "1234", passwd));
+
     return 0;
 }
diff --git a/snac.c b/snac.c
index 0238b7a..dd76e06 100644
--- a/snac.c
+++ b/snac.c
@@ -90,3 +90,36 @@ void snac_debug(snac *snac, int level, d_char *str)
         fprintf(stderr, "%s [%s] %s\n", tm, snac->uid, msg);
     }
 }
+
+
+d_char *hash_password(char *uid, char *passwd, char *nonce)
+/* hashes a password */
+{
+    xs *d_nonce = NULL;
+    xs *combi;
+    xs *hash;
+
+    if (nonce == NULL)
+        nonce = d_nonce = xs_fmt("%08x", random());
+
+    combi = xs_fmt("%s:%s:%s", nonce, uid, passwd);
+    hash  = xs_sha1_hex(combi, strlen(combi));
+
+    return xs_fmt("%s:%s", nonce, hash);
+}
+
+
+int check_password(char *uid, char *passwd, char *hash)
+/* checks a password */
+{
+    int ret = 0;
+    xs *spl = xs_splitn(hash, ":", 1);
+
+    if (xs_list_len(spl) == 2) {
+        xs *n_hash = hash_password(uid, passwd, xs_list_get(spl, 0));
+
+        ret = (strcmp(hash, n_hash) == 0);
+    }
+
+    return ret;
+}
diff --git a/snac.h b/snac.h
index 03c9c7b..1c56404 100644
--- a/snac.h
+++ b/snac.h
@@ -33,3 +33,6 @@ void snac_debug(snac *snac, int level, d_char *str);
 #define snac_log(snac, str) snac_debug(snac, 0, str)
 
 int validate_uid(char *uid);
+
+d_char *hash_password(char *uid, char *passwd, char *nonce);
+int check_password(char *uid, char *passwd, char *hash);