thodg/libgit2

2018-10-19T10:54:38

transport/http: Include non-default ports in Host header When the port is omitted, the server assumes the default port for the service is used (see https://developer.mozilla.org/en-US/docs/Web/HTTP/Headers/Host). In cases where the client provided a non-default port, it should be passed along. This hasn't been an issue so far as the git protocol doesn't include server-generated URIs. I encountered this when implementing Rust registry support for Sonatype Nexus. Rust's registry uses a git repository for the package index. Clients look at a file in the root of the package index to find the base URL for downloading the packages. Sonatype Nexus looks at the incoming HTTP request (Host header and URL) to determine the client-facing URL base as it may be running behind a load balancer or reverse proxy. This client-facing URL base is then used to construct the package download base URL. When libgit2 fetches the index from Nexus on a non-default port, Nexus trusts the incorrect Host header and generates an incorrect package download base URL.

diff --git a/src/transports/http.c b/src/transports/http.c
index 0942daf..5121996 100644
--- a/src/transports/http.c
+++ b/src/transports/http.c
@@ -208,7 +208,11 @@ static int gen_request(
 	git_buf_puts(buf, "User-Agent: ");
 	git_http__user_agent(buf);
 	git_buf_puts(buf, "\r\n");
-	git_buf_printf(buf, "Host: %s\r\n", t->connection_data.host);
+	git_buf_printf(buf, "Host: %s", t->connection_data.host);
+	if (strcmp(t->connection_data.port, gitno__default_port(&t->connection_data)) != 0) {
+		git_buf_printf(buf, ":%s", t->connection_data.port);
+	}
+	git_buf_puts(buf, "\r\n");
 
 	if (s->chunked || content_length > 0) {
 		git_buf_printf(buf, "Accept: application/x-git-%s-result\r\n", s->service);