gitweb: use new Git::Repo API, and add optional caching
[git/gitweb-caching.git] / mktag.c
blob0b34341f711a903d4a12fe96dc6ef63e55fb2f5b
1 #include "cache.h"
2 #include "tag.h"
4 /*
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)
23 int ret = -1;
24 enum object_type type;
25 unsigned long size;
26 void *buffer = read_sha1_file(sha1, &type, &size);
28 if (buffer) {
29 if (type == type_from_string(expected_type))
30 ret = check_sha1_signature(sha1, buffer, size, expected_type);
31 free(buffer);
33 return ret;
36 #ifdef NO_C99_FORMAT
37 #define PD_FMT "%d"
38 #else
39 #define PD_FMT "%td"
40 #endif
42 static int verify_tag(char *buffer, unsigned long size)
44 int typelen;
45 char type[20];
46 unsigned char sha1[20];
47 const char *object, *type_line, *tag_line, *tagger_line, *lb, *rb;
48 size_t len;
50 if (size < 84)
51 return error("wanna fool me ? you obviously got the size wrong !");
53 buffer[size] = 0;
55 /* Verify object line */
56 object = buffer;
57 if (memcmp(object, "object ", 7))
58 return error("char%d: does not start with \"object \"", 0);
60 if (get_sha1_hex(object + 7, sha1))
61 return error("char%d: could not get SHA1 hash", 7);
63 /* Verify type line */
64 type_line = object + 48;
65 if (memcmp(type_line - 1, "\ntype ", 6))
66 return error("char%d: could not find \"\\ntype \"", 47);
68 /* Verify tag-line */
69 tag_line = strchr(type_line, '\n');
70 if (!tag_line)
71 return error("char" PD_FMT ": could not find next \"\\n\"", type_line - buffer);
72 tag_line++;
73 if (memcmp(tag_line, "tag ", 4) || tag_line[4] == '\n')
74 return error("char" PD_FMT ": no \"tag \" found", tag_line - buffer);
76 /* Get the actual type */
77 typelen = tag_line - type_line - strlen("type \n");
78 if (typelen >= sizeof(type))
79 return error("char" PD_FMT ": type too long", type_line+5 - buffer);
81 memcpy(type, type_line+5, typelen);
82 type[typelen] = 0;
84 /* Verify that the object matches */
85 if (verify_object(sha1, type))
86 return error("char%d: could not verify object %s", 7, sha1_to_hex(sha1));
88 /* Verify the tag-name: we don't allow control characters or spaces in it */
89 tag_line += 4;
90 for (;;) {
91 unsigned char c = *tag_line++;
92 if (c == '\n')
93 break;
94 if (c > ' ')
95 continue;
96 return error("char" PD_FMT ": could not verify tag name", tag_line - buffer);
99 /* Verify the tagger line */
100 tagger_line = tag_line;
102 if (memcmp(tagger_line, "tagger ", 7))
103 return error("char" PD_FMT ": could not find \"tagger \"",
104 tagger_line - buffer);
107 * Check for correct form for name and email
108 * i.e. " <" followed by "> " on _this_ line
109 * No angle brackets within the name or email address fields.
110 * No spaces within the email address field.
112 tagger_line += 7;
113 if (!(lb = strstr(tagger_line, " <")) || !(rb = strstr(lb+2, "> ")) ||
114 strpbrk(tagger_line, "<>\n") != lb+1 ||
115 strpbrk(lb+2, "><\n ") != rb)
116 return error("char" PD_FMT ": malformed tagger field",
117 tagger_line - buffer);
119 /* Check for author name, at least one character, space is acceptable */
120 if (lb == tagger_line)
121 return error("char" PD_FMT ": missing tagger name",
122 tagger_line - buffer);
124 /* timestamp, 1 or more digits followed by space */
125 tagger_line = rb + 2;
126 if (!(len = strspn(tagger_line, "0123456789")))
127 return error("char" PD_FMT ": missing tag timestamp",
128 tagger_line - buffer);
129 tagger_line += len;
130 if (*tagger_line != ' ')
131 return error("char" PD_FMT ": malformed tag timestamp",
132 tagger_line - buffer);
133 tagger_line++;
135 /* timezone, 5 digits [+-]hhmm, max. 1400 */
136 if (!((tagger_line[0] == '+' || tagger_line[0] == '-') &&
137 strspn(tagger_line+1, "0123456789") == 4 &&
138 tagger_line[5] == '\n' && atoi(tagger_line+1) <= 1400))
139 return error("char" PD_FMT ": malformed tag timezone",
140 tagger_line - buffer);
141 tagger_line += 6;
143 /* Verify the blank line separating the header from the body */
144 if (*tagger_line != '\n')
145 return error("char" PD_FMT ": trailing garbage in tag header",
146 tagger_line - buffer);
148 /* The actual stuff afterwards we don't care about.. */
149 return 0;
152 #undef PD_FMT
154 int main(int argc, char **argv)
156 struct strbuf buf;
157 unsigned char result_sha1[20];
159 if (argc != 1)
160 usage("git-mktag < signaturefile");
162 setup_git_directory();
164 strbuf_init(&buf, 0);
165 if (strbuf_read(&buf, 0, 4096) < 0) {
166 die("could not read from stdin");
169 /* Verify it for some basic sanity: it needs to start with
170 "object <sha1>\ntype\ntagger " */
171 if (verify_tag(buf.buf, buf.len) < 0)
172 die("invalid tag signature file");
174 if (write_sha1_file(buf.buf, buf.len, tag_type, result_sha1) < 0)
175 die("unable to write tag file");
177 strbuf_release(&buf);
178 printf("%s\n", sha1_to_hex(result_sha1));
179 return 0;