- Use the MD4_SUM_LENGTH define in place of some hard-wired values.
- Pass the hostname in to auth_server().
- Generate a unique error for each failure type in auth_server() so
that the log-file contains why the authorization failed.
- Don't use sscanf() to parse the client's auth-challenge response.
diff --git a/authenticate.c b/authenticate.c
index ff24028..25d2ded 100644
--- a/authenticate.c
+++ b/authenticate.c
@@ -51,7 +51,7 @@
}
}
-/* create a 16 byte challenge buffer */
+/* Create a 16-byte challenge buffer. */
static void gen_challenge(char *addr, char *challenge)
{
char input[32];
@@ -195,17 +195,17 @@
return NULL;
}
-/* generate a 16 byte hash from a password and challenge */
+/* Generate a 16-byte hash from a password and challenge. */
static void generate_hash(char *in, char *challenge, char *out)
{
- char buf[16];
+ char buf[MD4_SUM_LENGTH];
sum_init(0);
sum_update(in, strlen(in));
sum_update(challenge, strlen(challenge));
sum_end(buf);
- base64_encode(buf, 16, out);
+ base64_encode(buf, MD4_SUM_LENGTH, out);
}
/* Possibly negotiate authentication with the client. Use "leader" to
@@ -214,17 +214,16 @@
* Return NULL if authentication failed. Return "" if anonymous access.
* Otherwise return username.
*/
-char *auth_server(int f_in, int f_out, int module, char *addr, char *leader)
+char *auth_server(int f_in, int f_out, int module, char *host, char *addr,
+ char *leader)
{
char *users = lp_auth_users(module);
- char challenge[16];
- char b64_challenge[30];
+ char challenge[MD4_SUM_LENGTH];
+ char b64_challenge[MD4_SUM_LENGTH*2];
char line[MAXPATHLEN];
- static char user[100];
- char secret[100];
- char pass[30];
- char pass2[30];
- char *tok;
+ char secret[512];
+ char pass2[MD4_SUM_LENGTH*2];
+ char *tok, *pass;
/* if no auth list then allow anyone in! */
if (!users || !*users)
@@ -232,52 +231,62 @@
gen_challenge(addr, challenge);
- base64_encode(challenge, 16, b64_challenge);
+ base64_encode(challenge, MD4_SUM_LENGTH, b64_challenge);
io_printf(f_out, "%s%s\n", leader, b64_challenge);
- if (!read_line(f_in, line, sizeof line - 1))
+ if (!read_line(f_in, line, sizeof line - 1)
+ || (pass = strchr(line, ' ')) == NULL) {
+ rprintf(FLOG, "auth failed on module %s from %s (%s): "
+ "invalid challenge response\n",
+ lp_name(module), host, addr);
return NULL;
+ }
+ *pass++ = '\0';
- memset(user, 0, sizeof user);
- memset(pass, 0, sizeof pass);
+ if (!(users = strdup(users)))
+ out_of_memory("auth_server");
- if (sscanf(line,"%99s %29s", user, pass) != 2)
- return NULL;
-
- users = strdup(users);
- if (!users)
- return NULL;
-
- for (tok=strtok(users," ,\t"); tok; tok = strtok(NULL," ,\t")) {
- if (wildmatch(tok, user))
+ for (tok = strtok(users, " ,\t"); tok; tok = strtok(NULL, " ,\t")) {
+ if (wildmatch(tok, line))
break;
}
free(users);
- if (!tok)
+ if (!tok) {
+ rprintf(FLOG, "auth failed on module %s from %s (%s): "
+ "unauthorized user\n",
+ lp_name(module), host, addr);
return NULL;
+ }
memset(secret, 0, sizeof secret);
- if (!get_secret(module, user, secret, sizeof secret - 1)) {
+ if (!get_secret(module, line, secret, sizeof secret - 1)) {
memset(secret, 0, sizeof secret);
+ rprintf(FLOG, "auth failed on module %s from %s (%s): "
+ "missing secret for user \"%s\"\n",
+ lp_name(module), host, addr, line);
return NULL;
}
generate_hash(secret, b64_challenge, pass2);
memset(secret, 0, sizeof secret);
- if (strcmp(pass, pass2) == 0)
- return user;
+ if (strcmp(pass, pass2) != 0) {
+ rprintf(FLOG, "auth failed on module %s from %s (%s): "
+ "password mismatch\n",
+ lp_name(module), host, addr);
+ return NULL;
+ }
- return NULL;
+ return strdup(line);
}
void auth_client(int fd, char *user, char *challenge)
{
char *pass;
- char pass2[30];
+ char pass2[MD4_SUM_LENGTH*2];
if (!user || !*user)
user = "nobody";