builtin-checkout.c: check error return from read_cache()

diff --git a/mktag.c b/mktag.c
index 38acd5a295d5f06fb2db60633e89a06ba634beb8..ba3d495e0715d83ffab3103e4d340a3b9ac4f4e7 100644 (file)
--- a/mktag.c
+++ b/mktag.c
@@ -8,10 +8,11 @@
  * message and a signature block that git itself doesn't care about,
  * but that can be verified with gpg or similar.
  *
- * The first three lines are guaranteed to be at least 63 bytes:
+ * The first four lines are guaranteed to be at least 83 bytes:
  * "object <sha1>\n" is 48 bytes, "type tag\n" at 9 bytes is the
- * shortest possible type-line, and "tag .\n" at 6 bytes is the
- * shortest single-character-tag line.
+ * shortest possible type-line, "tag .\n" at 6 bytes is the shortest
+ * single-character-tag line, and "tagger . <> 0 +0000\n" at 20 bytes is
+ * the shortest possible tagger-line.
  */
 
 /*
@@ -43,9 +44,10 @@ static int verify_tag(char *buffer, unsigned long size)
        int typelen;
        char type[20];
        unsigned char sha1[20];
-       const char *object, *type_line, *tag_line, *tagger_line;
+       const char *object, *type_line, *tag_line, *tagger_line, *lb, *rb;
+       size_t len;
 
-       if (size < 64)
+       if (size < 84)
                return error("wanna fool me ? you obviously got the size wrong !");
 
        buffer[size] = 0;
@@ -97,11 +99,51 @@ static int verify_tag(char *buffer, unsigned long size)
        /* Verify the tagger line */
        tagger_line = tag_line;
 
-       if (memcmp(tagger_line, "tagger", 6) || (tagger_line[6] == '\n'))
-               return error("char" PD_FMT ": could not find \"tagger\"", tagger_line - buffer);
-
-       /* TODO: check for committer info + blank line? */
-       /* Also, the minimum length is probably + "tagger .", or 63+8=71 */
+       if (memcmp(tagger_line, "tagger ", 7))
+               return error("char" PD_FMT ": could not find \"tagger \"",
+                       tagger_line - buffer);
+
+       /*
+        * Check for correct form for name and email
+        * i.e. " <" followed by "> " on _this_ line
+        * No angle brackets within the name or email address fields.
+        * No spaces within the email address field.
+        */
+       tagger_line += 7;
+       if (!(lb = strstr(tagger_line, " <")) || !(rb = strstr(lb+2, "> ")) ||
+               strpbrk(tagger_line, "<>\n") != lb+1 ||
+               strpbrk(lb+2, "><\n ") != rb)
+               return error("char" PD_FMT ": malformed tagger field",
+                       tagger_line - buffer);
+
+       /* Check for author name, at least one character, space is acceptable */
+       if (lb == tagger_line)
+               return error("char" PD_FMT ": missing tagger name",
+                       tagger_line - buffer);
+
+       /* timestamp, 1 or more digits followed by space */
+       tagger_line = rb + 2;
+       if (!(len = strspn(tagger_line, "0123456789")))
+               return error("char" PD_FMT ": missing tag timestamp",
+                       tagger_line - buffer);
+       tagger_line += len;
+       if (*tagger_line != ' ')
+               return error("char" PD_FMT ": malformed tag timestamp",
+                       tagger_line - buffer);
+       tagger_line++;
+
+       /* timezone, 5 digits [+-]hhmm, max. 1400 */
+       if (!((tagger_line[0] == '+' || tagger_line[0] == '-') &&
+             strspn(tagger_line+1, "0123456789") == 4 &&
+             tagger_line[5] == '\n' && atoi(tagger_line+1) <= 1400))
+               return error("char" PD_FMT ": malformed tag timezone",
+                       tagger_line - buffer);
+       tagger_line += 6;
+
+       /* Verify the blank line separating the header from the body */
+       if (*tagger_line != '\n')
+               return error("char" PD_FMT ": trailing garbage in tag header",
+                       tagger_line - buffer);
 
        /* The actual stuff afterwards we don't care about.. */
        return 0;
@@ -111,8 +153,7 @@ static int verify_tag(char *buffer, unsigned long size)
 
 int main(int argc, char **argv)
 {
-       unsigned long size = 4096;
-       char *buffer = xmalloc(size);
+       struct strbuf buf = STRBUF_INIT;
        unsigned char result_sha1[20];
 
        if (argc != 1)
@@ -120,21 +161,19 @@ int main(int argc, char **argv)
 
        setup_git_directory();
 
-       if (read_fd(0, &buffer, &size)) {
-               free(buffer);
+       if (strbuf_read(&buf, 0, 4096) < 0) {
                die("could not read from stdin");
        }
 
        /* Verify it for some basic sanity: it needs to start with
           "object <sha1>\ntype\ntagger " */
-       if (verify_tag(buffer, size) < 0)
+       if (verify_tag(buf.buf, buf.len) < 0)
                die("invalid tag signature file");
 
-       if (write_sha1_file(buffer, size, tag_type, result_sha1) < 0)
+       if (write_sha1_file(buf.buf, buf.len, tag_type, result_sha1) < 0)
                die("unable to write tag file");
 
-       free(buffer);
-
+       strbuf_release(&buf);
        printf("%s\n", sha1_to_hex(result_sha1));
        return 0;
 }