Use a static buffer to read the password file entries from.

That allows easier overwrite of the parameters read.

src/common.h

@@ -59,5 +59,20 @@ int recv_socket_msg(void *pool, int fd, uint8_t cmd,
 
 const char* cmd_request_to_str(unsigned cmd);
 
+inline static
+void safe_memset(void *data, int c, size_t size)
+{
+	volatile unsigned volatile_zero = 0;
+	volatile char *vdata = (volatile char*)data;
+
+	/* This is based on a nice trick for safe memset,
+	 * sent by David Jacobson in the openssl-dev mailing list.
+	 */
+
+	do {
+		memset(data, c, size);
+	} while(vdata[volatile_zero] != c);
+}
+
 #endif
 

src/plain.c

@@ -47,8 +47,7 @@ static int read_auth_pass(struct plain_ctx_st *pctx)
 {
 	unsigned groupname_size;
 	FILE *fp;
-	char *line = NULL;
-	size_t len;
+	char line[512];
 	ssize_t ll;
 	char *p, *sp;
 	int ret;
@@ -61,7 +60,10 @@ static int read_auth_pass(struct plain_ctx_st *pctx)
 		return -1;
 	}
 
-	while ((ll = getline(&line, &len, fp)) > 0) {
+	line[sizeof(line)-1] = 0;
+	while ((p=fgets(line, sizeof(line)-1, fp)) != NULL) {
+		ll = strlen(p);
+
 		if (ll <= 4)
 			continue;
 
@@ -100,8 +102,8 @@ static int read_auth_pass(struct plain_ctx_st *pctx)
 	/* always succeed */
 	ret = 0;
  exit:
+	safe_memset(line, 0, sizeof(line));
 	fclose(fp);
-	free(line); /* no talloc_free, as it is provided by getline */
 	return ret;
 }