t1501: demonstrate NULL pointer access with invalid GIT_WORK_TREE
[git.git] / tag.c
blob243d1fdbbcb1424b0082e1c999920f6a50b32d68
1 #include "cache.h"
2 #include "tag.h"
3 #include "commit.h"
4 #include "tree.h"
5 #include "blob.h"
6 #include "gpg-interface.h"
8 const char *tag_type = "tag";
10 static int run_gpg_verify(const char *buf, unsigned long size, unsigned flags)
12 struct signature_check sigc;
13 size_t payload_size;
14 int ret;
16 memset(&sigc, 0, sizeof(sigc));
18 payload_size = parse_signature(buf, size);
20 if (size == payload_size) {
21 if (flags & GPG_VERIFY_VERBOSE)
22 write_in_full(1, buf, payload_size);
23 return error("no signature found");
26 ret = check_signature(buf, payload_size, buf + payload_size,
27 size - payload_size, &sigc);
29 if (!(flags & GPG_VERIFY_OMIT_STATUS))
30 print_signature_buffer(&sigc, flags);
32 signature_check_clear(&sigc);
33 return ret;
36 int gpg_verify_tag(const unsigned char *sha1, const char *name_to_report,
37 unsigned flags)
39 enum object_type type;
40 char *buf;
41 unsigned long size;
42 int ret;
44 type = sha1_object_info(sha1, NULL);
45 if (type != OBJ_TAG)
46 return error("%s: cannot verify a non-tag object of type %s.",
47 name_to_report ?
48 name_to_report :
49 find_unique_abbrev(sha1, DEFAULT_ABBREV),
50 typename(type));
52 buf = read_sha1_file(sha1, &type, &size);
53 if (!buf)
54 return error("%s: unable to read file.",
55 name_to_report ?
56 name_to_report :
57 find_unique_abbrev(sha1, DEFAULT_ABBREV));
59 ret = run_gpg_verify(buf, size, flags);
61 free(buf);
62 return ret;
65 struct object *deref_tag(struct object *o, const char *warn, int warnlen)
67 while (o && o->type == OBJ_TAG)
68 if (((struct tag *)o)->tagged)
69 o = parse_object(((struct tag *)o)->tagged->oid.hash);
70 else
71 o = NULL;
72 if (!o && warn) {
73 if (!warnlen)
74 warnlen = strlen(warn);
75 error("missing object referenced by '%.*s'", warnlen, warn);
77 return o;
80 struct object *deref_tag_noverify(struct object *o)
82 while (o && o->type == OBJ_TAG) {
83 o = parse_object(o->oid.hash);
84 if (o && o->type == OBJ_TAG && ((struct tag *)o)->tagged)
85 o = ((struct tag *)o)->tagged;
86 else
87 o = NULL;
89 return o;
92 struct tag *lookup_tag(const unsigned char *sha1)
94 struct object *obj = lookup_object(sha1);
95 if (!obj)
96 return create_object(sha1, alloc_tag_node());
97 return object_as_type(obj, OBJ_TAG, 0);
100 static unsigned long parse_tag_date(const char *buf, const char *tail)
102 const char *dateptr;
104 while (buf < tail && *buf++ != '>')
105 /* nada */;
106 if (buf >= tail)
107 return 0;
108 dateptr = buf;
109 while (buf < tail && *buf++ != '\n')
110 /* nada */;
111 if (buf >= tail)
112 return 0;
113 /* dateptr < buf && buf[-1] == '\n', so strtoul will stop at buf-1 */
114 return strtoul(dateptr, NULL, 10);
117 int parse_tag_buffer(struct tag *item, const void *data, unsigned long size)
119 unsigned char sha1[20];
120 char type[20];
121 const char *bufptr = data;
122 const char *tail = bufptr + size;
123 const char *nl;
125 if (item->object.parsed)
126 return 0;
127 item->object.parsed = 1;
129 if (size < 64)
130 return -1;
131 if (memcmp("object ", bufptr, 7) || get_sha1_hex(bufptr + 7, sha1) || bufptr[47] != '\n')
132 return -1;
133 bufptr += 48; /* "object " + sha1 + "\n" */
135 if (!starts_with(bufptr, "type "))
136 return -1;
137 bufptr += 5;
138 nl = memchr(bufptr, '\n', tail - bufptr);
139 if (!nl || sizeof(type) <= (nl - bufptr))
140 return -1;
141 memcpy(type, bufptr, nl - bufptr);
142 type[nl - bufptr] = '\0';
143 bufptr = nl + 1;
145 if (!strcmp(type, blob_type)) {
146 item->tagged = &lookup_blob(sha1)->object;
147 } else if (!strcmp(type, tree_type)) {
148 item->tagged = &lookup_tree(sha1)->object;
149 } else if (!strcmp(type, commit_type)) {
150 item->tagged = &lookup_commit(sha1)->object;
151 } else if (!strcmp(type, tag_type)) {
152 item->tagged = &lookup_tag(sha1)->object;
153 } else {
154 error("Unknown type %s", type);
155 item->tagged = NULL;
158 if (bufptr + 4 < tail && starts_with(bufptr, "tag "))
159 ; /* good */
160 else
161 return -1;
162 bufptr += 4;
163 nl = memchr(bufptr, '\n', tail - bufptr);
164 if (!nl)
165 return -1;
166 item->tag = xmemdupz(bufptr, nl - bufptr);
167 bufptr = nl + 1;
169 if (bufptr + 7 < tail && starts_with(bufptr, "tagger "))
170 item->date = parse_tag_date(bufptr, tail);
171 else
172 item->date = 0;
174 return 0;
177 int parse_tag(struct tag *item)
179 enum object_type type;
180 void *data;
181 unsigned long size;
182 int ret;
184 if (item->object.parsed)
185 return 0;
186 data = read_sha1_file(item->object.oid.hash, &type, &size);
187 if (!data)
188 return error("Could not read %s",
189 oid_to_hex(&item->object.oid));
190 if (type != OBJ_TAG) {
191 free(data);
192 return error("Object %s not a tag",
193 oid_to_hex(&item->object.oid));
195 ret = parse_tag_buffer(item, data, size);
196 free(data);
197 return ret;