public key loading: multiline, skip comments

The public key is specified as DNS RR. Before this patch, only first
line of the input file was read even if it contained comment, white
spaces or just a part of the RR.

refs #2413

Change-Id: I4cf3374121fbb676d89a52fa4ba741e497b04564

src/libknot/sign/key.c

@@ -88,9 +88,9 @@ static char *strndup_with_suffix(const char *base, int length, char *suffix)
 	return result;
 }
 
-static void key_scan_noop(const scanner_t *s)
+static void key_scan_set_done(const scanner_t *s)
 {
-	UNUSED(s);
+	*((bool *)s->data) = true;
 }
 
 /*!
@@ -113,32 +113,39 @@ static int get_key_info_from_public_key(const char *filename,
 		return KNOT_ENOMEM;
 	}
 
-	scanner->process_record = key_scan_noop;
-	scanner->process_error = key_scan_noop;
+	bool scan_done = false;
+	bool last_block = false;
+
+	scanner->process_record = key_scan_set_done;
+	scanner->process_error = key_scan_set_done;
 	scanner->default_ttl = 0;
 	scanner->default_class = KNOT_CLASS_IN;
 	scanner->zone_origin[0] = '\0';
 	scanner->zone_origin_length = 1;
+	scanner->data = (void *)&scan_done;
 
 	char *buffer = NULL;
 	size_t buffer_size;
-	ssize_t read = knot_getline(&buffer, &buffer_size, keyfile);
-
-	fclose(keyfile);
+	ssize_t read;
+	int result = 0;
 
-	if (read == -1) {
-		scanner_free(scanner);
-		return KNOT_KEY_EPUBLIC_KEY_INVALID;
+	while (!scan_done && !last_block && result == 0) {
+		read = knot_getline(&buffer, &buffer_size, keyfile);
+		if (read <= 0) {
+			last_block = true;
+			read = 0;
+		}
+		result = scanner_process(buffer, buffer + read, last_block,
+		                         scanner);
 	}
 
-	if (scanner_process(buffer, buffer + read, true, scanner) != 0) {
-		free(buffer);
+	free(buffer);
+
+	if (scanner->r_type != KNOT_RRTYPE_DNSKEY) {
 		scanner_free(scanner);
 		return KNOT_KEY_EPUBLIC_KEY_INVALID;
 	}
 
-	free(buffer);
-
 	knot_dname_t *owner = knot_dname_new_from_wire(scanner->r_owner,
 	                                               scanner->r_owner_length,
 	                                               NULL);