]>
git.ipfire.org Git - thirdparty/git.git/blob - mktag.c
5 * A signature file has a very simple fixed format: four lines
6 * of "object <sha1>" + "type <typename>" + "tag <tagname>" +
7 * "tagger <committer>", followed by a blank line, a free-form tag
8 * message and a signature block that git itself doesn't care about,
9 * but that can be verified with gpg or similar.
11 * The first four lines are guaranteed to be at least 83 bytes:
12 * "object <sha1>\n" is 48 bytes, "type tag\n" at 9 bytes is the
13 * shortest possible type-line, "tag .\n" at 6 bytes is the shortest
14 * single-character-tag line, and "tagger . <> 0 +0000\n" at 20 bytes is
15 * the shortest possible tagger-line.
19 * We refuse to tag something we can't verify. Just because.
21 static int verify_object(unsigned char *sha1
, const char *expected_type
)
24 enum object_type type
;
26 void *buffer
= read_sha1_file(sha1
, &type
, &size
);
29 if (type
== type_from_string(expected_type
))
30 ret
= check_sha1_signature(sha1
, buffer
, size
, expected_type
);
42 static int verify_tag(char *buffer
, unsigned long size
)
46 unsigned char sha1
[20];
47 const char *object
, *type_line
, *tag_line
, *tagger_line
, *lb
, *rb
;
50 return error("wanna fool me ? you obviously got the size wrong !");
54 /* Verify object line */
56 if (memcmp(object
, "object ", 7))
57 return error("char%d: does not start with \"object \"", 0);
59 if (get_sha1_hex(object
+ 7, sha1
))
60 return error("char%d: could not get SHA1 hash", 7);
62 /* Verify type line */
63 type_line
= object
+ 48;
64 if (memcmp(type_line
- 1, "\ntype ", 6))
65 return error("char%d: could not find \"\\ntype \"", 47);
68 tag_line
= strchr(type_line
, '\n');
70 return error("char" PD_FMT
": could not find next \"\\n\"", type_line
- buffer
);
72 if (memcmp(tag_line
, "tag ", 4) || tag_line
[4] == '\n')
73 return error("char" PD_FMT
": no \"tag \" found", tag_line
- buffer
);
75 /* Get the actual type */
76 typelen
= tag_line
- type_line
- strlen("type \n");
77 if (typelen
>= sizeof(type
))
78 return error("char" PD_FMT
": type too long", type_line
+5 - buffer
);
80 memcpy(type
, type_line
+5, typelen
);
83 /* Verify that the object matches */
84 if (verify_object(sha1
, type
))
85 return error("char%d: could not verify object %s", 7, sha1_to_hex(sha1
));
87 /* Verify the tag-name: we don't allow control characters or spaces in it */
90 unsigned char c
= *tag_line
++;
95 return error("char" PD_FMT
": could not verify tag name", tag_line
- buffer
);
98 /* Verify the tagger line */
99 tagger_line
= tag_line
;
101 if (memcmp(tagger_line
, "tagger ", 7) || (tagger_line
[7] == '\n'))
102 return error("char" PD_FMT
": could not find \"tagger \"",
103 tagger_line
- buffer
);
106 * Check for correct form for name and email
107 * i.e. " <" followed by "> " on _this_ line
110 if (!(lb
= strstr(tagger_line
, " <")) || !(rb
= strstr(lb
+2, "> ")) ||
111 strchr(tagger_line
, '\n') < rb
)
112 return error("char" PD_FMT
": malformed tagger",
113 tagger_line
- buffer
);
115 /* Check for author name, at least one character, space is acceptable */
116 if (lb
== tagger_line
)
117 return error("char" PD_FMT
": missing tagger name",
118 tagger_line
- buffer
);
121 tagger_line
= rb
+ 2;
122 if (*tagger_line
== ' ')
123 return error("char" PD_FMT
": malformed tag timestamp",
124 tagger_line
- buffer
);
126 unsigned char c
= *tagger_line
++;
131 return error("char" PD_FMT
": malformed tag timestamp",
132 tagger_line
- buffer
);
135 /* timezone, 5 digits [+-]hhmm, max. 1400 */
136 if (!((tagger_line
[0] == '+' || tagger_line
[0] == '-') &&
137 isdigit(tagger_line
[1]) && isdigit(tagger_line
[2]) &&
138 isdigit(tagger_line
[3]) && isdigit(tagger_line
[4]) &&
139 tagger_line
[5] == '\n' && atoi(tagger_line
+1) <= 1400))
140 return error("char" PD_FMT
": malformed tag timezone",
141 tagger_line
- buffer
);
144 /* Verify the blank line separating the header from the body */
145 if (*tagger_line
!= '\n')
146 return error("char" PD_FMT
": trailing garbage in tag header",
147 tagger_line
- buffer
);
149 /* The actual stuff afterwards we don't care about.. */
155 int main(int argc
, char **argv
)
158 unsigned char result_sha1
[20];
161 usage("git-mktag < signaturefile");
163 setup_git_directory();
165 strbuf_init(&buf
, 0);
166 if (strbuf_read(&buf
, 0, 4096) < 0) {
167 die("could not read from stdin");
170 /* Verify it for some basic sanity: it needs to start with
171 "object <sha1>\ntype\ntagger " */
172 if (verify_tag(buf
.buf
, buf
.len
) < 0)
173 die("invalid tag signature file");
175 if (write_sha1_file(buf
.buf
, buf
.len
, tag_type
, result_sha1
) < 0)
176 die("unable to write tag file");
178 strbuf_release(&buf
);
179 printf("%s\n", sha1_to_hex(result_sha1
));