hash-object --literally: fix buffer overrun with extra-long object type

diff --git a/sha1_file.c b/sha1_file.c
index c08c0cbea805b38104504b9b51266949affb6991..dc940e63c453199dd9a7285533fbf2355bab03d1 100644 (file)
--- a/sha1_file.c
+++ b/sha1_file.c
@@ -2962,6 +2962,27 @@ int write_sha1_file(const void *buf, unsigned long len, const char *type, unsign
        return write_loose_object(sha1, hdr, hdrlen, buf, len, 0);
 }
 
+int hash_sha1_file_literally(const void *buf, unsigned long len, const char *type,
+                            unsigned char *sha1, unsigned flags)
+{
+       char *header;
+       int hdrlen, status = 0;
+
+       /* type string, SP, %lu of the length plus NUL must fit this */
+       header = xmalloc(strlen(type) + 32);
+       write_sha1_file_prepare(buf, len, type, sha1, header, &hdrlen);
+
+       if (!(flags & HASH_WRITE_OBJECT))
+               goto cleanup;
+       if (has_sha1_file(sha1))
+               goto cleanup;
+       status = write_loose_object(sha1, header, hdrlen, buf, len, 0);
+
+cleanup:
+       free(header);
+       return status;
+}
+
 int force_object_loose(const unsigned char *sha1, time_t mtime)
 {
        void *buf;