1 files changed, 146 insertions, 0 deletions
diff --git a/lib/pathbuf.c b/lib/pathbuf.c
new file mode 100644
index 0000000000..a5d6316fcd
--- /dev/null
+++ b/lib/pathbuf.c
@@ -0,0 +1,146 @@
+/*
+ * Copyright (C) 2010-2022 Free Software Foundation, Inc.
+ * Copyright (C) 2022 Red Hat, Inc.
+ *
+ * Author: Daiki Ueno
+ *
+ * This file is part of GnuTLS.
+ *
+ * The GnuTLS is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public License
+ * as published by the Free Software Foundation; either version 2.1 of
+ * the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>
+ *
+ */
+
+#include "config.h"
+
+#include "pathbuf.h"
+#include "gnutls_int.h"
+#include <limits.h>
+#include "intprops.h"
+
+static int
+pathbuf_reserve(struct gnutls_pathbuf_st *buffer, size_t to_add)
+{
+	size_t len;
+	char *ptr;
+
+	len = buffer->len;
+
+	if (INT_ADD_OVERFLOW(len, to_add)) {
+		return gnutls_assert_val(GNUTLS_E_INVALID_REQUEST);
+	}
+	len += to_add;
+
+	/* NUL terminator.  */
+	if (INT_ADD_OVERFLOW(len, 1)) {
+		return gnutls_assert_val(GNUTLS_E_INVALID_REQUEST);
+	}
+	len++;
+
+	if (len <= buffer->cap) {
+		return 0;
+	}
+
+	if (buffer->ptr == buffer->base) {
+		ptr = gnutls_strdup(buffer->ptr);
+		if (!ptr) {
+			return gnutls_assert_val(GNUTLS_E_MEMORY_ERROR);
+		}
+		buffer->ptr = ptr;
+	}
+
+	ptr = gnutls_realloc(buffer->ptr, len);
+	if (!ptr) {
+		return gnutls_assert_val(GNUTLS_E_MEMORY_ERROR);
+	}
+
+	buffer->ptr = ptr;
+	buffer->cap = len;
+
+	return 0;
+}
+
+int
+_gnutls_pathbuf_init(struct gnutls_pathbuf_st *buffer, const char *base)
+{
+	size_t len;
+	int ret;
+
+	memset(buffer, 0, sizeof(*buffer));
+	buffer->cap = sizeof(buffer->base);
+	buffer->ptr = buffer->base;
+
+	len = strlen(base);
+
+	ret = pathbuf_reserve(buffer, len);
+	if (ret < 0) {
+		return ret;
+	}
+
+	strcpy(buffer->ptr, base);
+	buffer->len = len;
+
+	return 0;
+}
+
+int
+_gnutls_pathbuf_append(struct gnutls_pathbuf_st *buffer, const char *component)
+{
+	size_t len;
+	char *p;
+	int ret;
+
+	len = strlen(component);
+
+	/* Path separator.  */
+	if (INT_ADD_OVERFLOW(len, 1)) {
+		return gnutls_assert_val(GNUTLS_E_INVALID_REQUEST);
+	}
+	len++;
+
+	ret = pathbuf_reserve(buffer, len);
+	if (ret < 0) {
+		return ret;
+	}
+
+	p = stpcpy(&buffer->ptr[buffer->len], "/");
+	strcpy(p, component);
+
+	/* Overflow is already checked in the call to pathbuf_reserve
+	 * above.
+	 */
+	buffer->len += len;
+
+	return 0;
+}
+
+int
+_gnutls_pathbuf_truncate(struct gnutls_pathbuf_st *buffer, size_t len)
+{
+	if (len > buffer->len) {
+		return gnutls_assert_val(GNUTLS_E_INVALID_REQUEST);
+	}
+	buffer->len = len;
+	buffer->ptr[len] = '\0';
+	return 0;
+}
+
+void
+_gnutls_pathbuf_deinit(struct gnutls_pathbuf_st *buffer)
+{
+	if (buffer->ptr != buffer->base) {
+		gnutls_free(buffer->ptr);
+	}
+	memset(buffer, 0, sizeof(*buffer));
+}
+