snapshot: support tar signature for compressed tar

This adds support for kernel.org style signatures where the uncompressed
tar archive is signed and compressed later. The signature is valid for
all tar* snapshots.

We have a filter which snapshots may be generated and downloaded. This has
to allow tar signatures now even if tar itself is not allowed. To simplify
things we allow all signatures.

Signed-off-by: Christian Hesse <mail@eworm.de>

2 files changed, 10 insertions, 2 deletions

diff --git a/ui-shared.c b/ui-shared.c
index 9a2e382..066a470 100644
--- a/ui-shared.c
+++ b/ui-shared.c
@@ -1114,7 +1114,7 @@ void cgit_compose_snapshot_prefix(struct strbuf *filename, const char *base,
 void cgit_print_snapshot_links(const struct cgit_repo *repo, const char *ref,
                                const char *separator)
 {
-        const struct cgit_snapshot_format* f;
+        const struct cgit_snapshot_format *f;
         struct strbuf filename = STRBUF_INIT;
         const char *basename;
         size_t prefixlen;
@@ -1139,6 +1139,13 @@ void cgit_print_snapshot_links(const struct cgit_repo *repo, const char *ref,
                         cgit_snapshot_link("sig", NULL, NULL, NULL, NULL,
                                            filename.buf);
                         html(")");
+                } else if (starts_with(f->suffix, ".tar") && cgit_snapshot_get_sig(ref, &cgit_snapshot_formats[0])) {
+                        strbuf_setlen(&filename, strlen(filename.buf) - strlen(f->suffix));
+                        strbuf_addstr(&filename, ".tar.asc");
+                        html(" (");
+                        cgit_snapshot_link("sig", NULL, NULL, NULL, NULL,
+                                           filename.buf);
+                        html(")");
                 }
                 html(separator);
         }
diff --git a/ui-snapshot.c b/ui-snapshot.c
index 92c3277..fa3ceaf 100644
--- a/ui-snapshot.c
+++ b/ui-snapshot.c
@@ -86,6 +86,7 @@ static int write_tar_xz_archive(const char *hex, const char *prefix)
 }
 
 const struct cgit_snapshot_format cgit_snapshot_formats[] = {
+        /* .tar must remain the 0 index */
         { ".tar",       "application/x-tar",    write_tar_archive       },
         { ".tar.gz",    "application/x-gzip",   write_tar_gzip_archive  },
         { ".tar.bz2",   "application/x-bzip2",  write_tar_bzip2_archive },
@@ -268,7 +269,7 @@ void cgit_print_snapshot(const char *head, const char *hex,
         }
 
         f = get_format(filename);
-        if (!f || !(ctx.repo->snapshots & cgit_snapshot_format_bit(f))) {
+        if (!f || (!sig_filename && !(ctx.repo->snapshots & cgit_snapshot_format_bit(f)))) {
                 cgit_print_error_page(400, "Bad request",
                                 "Unsupported snapshot format: %s", filename);
                 return;