Merge branch 'jt/http-redact-cookies' into maint
[git.git] / builtin / mktag.c
blob031b750f068dea5e1652129a5df6d684f6bca850
1 #include "builtin.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(const 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);
27 const unsigned char *repl = lookup_replace_object(sha1);
29 if (buffer) {
30 if (type == type_from_string(expected_type))
31 ret = check_sha1_signature(repl, buffer, size, expected_type);
32 free(buffer);
34 return ret;
37 static int verify_tag(char *buffer, unsigned long size)
39 int typelen;
40 char type[20];
41 unsigned char sha1[20];
42 const char *object, *type_line, *tag_line, *tagger_line, *lb, *rb;
43 size_t len;
45 if (size < 84)
46 return error("wanna fool me ? you obviously got the size wrong !");
48 buffer[size] = 0;
50 /* Verify object line */
51 object = buffer;
52 if (memcmp(object, "object ", 7))
53 return error("char%d: does not start with \"object \"", 0);
55 if (get_sha1_hex(object + 7, sha1))
56 return error("char%d: could not get SHA1 hash", 7);
58 /* Verify type line */
59 type_line = object + 48;
60 if (memcmp(type_line - 1, "\ntype ", 6))
61 return error("char%d: could not find \"\\ntype \"", 47);
63 /* Verify tag-line */
64 tag_line = strchr(type_line, '\n');
65 if (!tag_line)
66 return error("char%"PRIuMAX": could not find next \"\\n\"",
67 (uintmax_t) (type_line - buffer));
68 tag_line++;
69 if (memcmp(tag_line, "tag ", 4) || tag_line[4] == '\n')
70 return error("char%"PRIuMAX": no \"tag \" found",
71 (uintmax_t) (tag_line - buffer));
73 /* Get the actual type */
74 typelen = tag_line - type_line - strlen("type \n");
75 if (typelen >= sizeof(type))
76 return error("char%"PRIuMAX": type too long",
77 (uintmax_t) (type_line+5 - buffer));
79 memcpy(type, type_line+5, typelen);
80 type[typelen] = 0;
82 /* Verify that the object matches */
83 if (verify_object(sha1, type))
84 return error("char%d: could not verify object %s", 7, sha1_to_hex(sha1));
86 /* Verify the tag-name: we don't allow control characters or spaces in it */
87 tag_line += 4;
88 for (;;) {
89 unsigned char c = *tag_line++;
90 if (c == '\n')
91 break;
92 if (c > ' ')
93 continue;
94 return error("char%"PRIuMAX": could not verify tag name",
95 (uintmax_t) (tag_line - buffer));
98 /* Verify the tagger line */
99 tagger_line = tag_line;
101 if (memcmp(tagger_line, "tagger ", 7))
102 return error("char%"PRIuMAX": could not find \"tagger \"",
103 (uintmax_t) (tagger_line - buffer));
106 * Check for correct form for name and email
107 * i.e. " <" followed by "> " on _this_ line
108 * No angle brackets within the name or email address fields.
109 * No spaces within the email address field.
111 tagger_line += 7;
112 if (!(lb = strstr(tagger_line, " <")) || !(rb = strstr(lb+2, "> ")) ||
113 strpbrk(tagger_line, "<>\n") != lb+1 ||
114 strpbrk(lb+2, "><\n ") != rb)
115 return error("char%"PRIuMAX": malformed tagger field",
116 (uintmax_t) (tagger_line - buffer));
118 /* Check for author name, at least one character, space is acceptable */
119 if (lb == tagger_line)
120 return error("char%"PRIuMAX": missing tagger name",
121 (uintmax_t) (tagger_line - buffer));
123 /* timestamp, 1 or more digits followed by space */
124 tagger_line = rb + 2;
125 if (!(len = strspn(tagger_line, "0123456789")))
126 return error("char%"PRIuMAX": missing tag timestamp",
127 (uintmax_t) (tagger_line - buffer));
128 tagger_line += len;
129 if (*tagger_line != ' ')
130 return error("char%"PRIuMAX": malformed tag timestamp",
131 (uintmax_t) (tagger_line - buffer));
132 tagger_line++;
134 /* timezone, 5 digits [+-]hhmm, max. 1400 */
135 if (!((tagger_line[0] == '+' || tagger_line[0] == '-') &&
136 strspn(tagger_line+1, "0123456789") == 4 &&
137 tagger_line[5] == '\n' && atoi(tagger_line+1) <= 1400))
138 return error("char%"PRIuMAX": malformed tag timezone",
139 (uintmax_t) (tagger_line - buffer));
140 tagger_line += 6;
142 /* Verify the blank line separating the header from the body */
143 if (*tagger_line != '\n')
144 return error("char%"PRIuMAX": trailing garbage in tag header",
145 (uintmax_t) (tagger_line - buffer));
147 /* The actual stuff afterwards we don't care about.. */
148 return 0;
151 int cmd_mktag(int argc, const char **argv, const char *prefix)
153 struct strbuf buf = STRBUF_INIT;
154 unsigned char result_sha1[20];
156 if (argc != 1)
157 usage("git mktag");
159 if (strbuf_read(&buf, 0, 4096) < 0) {
160 die_errno("could not read from stdin");
163 /* Verify it for some basic sanity: it needs to start with
164 "object <sha1>\ntype\ntagger " */
165 if (verify_tag(buf.buf, buf.len) < 0)
166 die("invalid tag signature file");
168 if (write_sha1_file(buf.buf, buf.len, tag_type, result_sha1) < 0)
169 die("unable to write tag file");
171 strbuf_release(&buf);
172 printf("%s\n", sha1_to_hex(result_sha1));
173 return 0;