mktag.c: improve verification of tagger field and tests

diff --git a/mktag.c b/mktag.c
index b05260c83fd8ef766eb2e16fa355501bf1f62fb5..8887080a665b86ceec5b08d06a8e3c7f57281eb2 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 +44,9 @@ 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;
 
-       if (size < 64)
+       if (size < 84)
                return error("wanna fool me ? you obviously got the size wrong !");
 
        buffer[size] = 0;
@@ -97,11 +98,53 @@ 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);
+       if (memcmp(tagger_line, "tagger ", 7) || (tagger_line[7] == '\n'))
+               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
+        */
+       tagger_line += 7;
+       if (!(lb = strstr(tagger_line, " <")) || !(rb = strstr(lb+2, "> ")) ||
+               strchr(tagger_line, '\n') < rb)
+               return error("char" PD_FMT ": malformed tagger",
+                       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 */
+       tagger_line = rb + 2;
+       if (*tagger_line == ' ')
+               return error("char" PD_FMT ": malformed tag timestamp",
+                       tagger_line - buffer);
+       for (;;) {
+               unsigned char c = *tagger_line++;
+               if (c == ' ')
+                       break;
+               if (isdigit(c))
+                       continue;
+               return error("char" PD_FMT ": malformed tag timestamp",
+                       tagger_line - buffer);
+       }
 
-       /* TODO: check for committer info + blank line? */
-       /* Also, the minimum length is probably + "tagger .", or 63+8=71 */
+       /* timezone, 5 digits [+-]hhmm, max. 1400 */
+       if (!((tagger_line[0] == '+' || tagger_line[0] == '-') &&
+             isdigit(tagger_line[1]) && isdigit(tagger_line[2]) &&
+             isdigit(tagger_line[3]) && isdigit(tagger_line[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;