Merge branch 'nd/sha1-file-delta-stack-leakage-fix'
[git] / credential-store.c
1 #include "cache.h"
2 #include "credential.h"
3 #include "string-list.h"
4 #include "parse-options.h"
5
6 static struct lock_file credential_lock;
7
8 static void parse_credential_file(const char *fn,
9                                   struct credential *c,
10                                   void (*match_cb)(struct credential *),
11                                   void (*other_cb)(struct strbuf *))
12 {
13         FILE *fh;
14         struct strbuf line = STRBUF_INIT;
15         struct credential entry = CREDENTIAL_INIT;
16
17         fh = fopen(fn, "r");
18         if (!fh) {
19                 if (errno != ENOENT)
20                         die_errno("unable to open %s", fn);
21                 return;
22         }
23
24         while (strbuf_getline(&line, fh, '\n') != EOF) {
25                 credential_from_url(&entry, line.buf);
26                 if (entry.username && entry.password &&
27                     credential_match(c, &entry)) {
28                         if (match_cb) {
29                                 match_cb(&entry);
30                                 break;
31                         }
32                 }
33                 else if (other_cb)
34                         other_cb(&line);
35         }
36
37         credential_clear(&entry);
38         strbuf_release(&line);
39         fclose(fh);
40 }
41
42 static void print_entry(struct credential *c)
43 {
44         printf("username=%s\n", c->username);
45         printf("password=%s\n", c->password);
46 }
47
48 static void print_line(struct strbuf *buf)
49 {
50         strbuf_addch(buf, '\n');
51         write_or_die(credential_lock.fd, buf->buf, buf->len);
52 }
53
54 static void rewrite_credential_file(const char *fn, struct credential *c,
55                                     struct strbuf *extra)
56 {
57         if (hold_lock_file_for_update(&credential_lock, fn, 0) < 0)
58                 die_errno("unable to get credential storage lock");
59         if (extra)
60                 print_line(extra);
61         parse_credential_file(fn, c, NULL, print_line);
62         if (commit_lock_file(&credential_lock) < 0)
63                 die_errno("unable to commit credential store");
64 }
65
66 static void store_credential(const char *fn, struct credential *c)
67 {
68         struct strbuf buf = STRBUF_INIT;
69
70         /*
71          * Sanity check that what we are storing is actually sensible.
72          * In particular, we can't make a URL without a protocol field.
73          * Without either a host or pathname (depending on the scheme),
74          * we have no primary key. And without a username and password,
75          * we are not actually storing a credential.
76          */
77         if (!c->protocol || !(c->host || c->path) ||
78             !c->username || !c->password)
79                 return;
80
81         strbuf_addf(&buf, "%s://", c->protocol);
82         strbuf_addstr_urlencode(&buf, c->username, 1);
83         strbuf_addch(&buf, ':');
84         strbuf_addstr_urlencode(&buf, c->password, 1);
85         strbuf_addch(&buf, '@');
86         if (c->host)
87                 strbuf_addstr_urlencode(&buf, c->host, 1);
88         if (c->path) {
89                 strbuf_addch(&buf, '/');
90                 strbuf_addstr_urlencode(&buf, c->path, 0);
91         }
92
93         rewrite_credential_file(fn, c, &buf);
94         strbuf_release(&buf);
95 }
96
97 static void remove_credential(const char *fn, struct credential *c)
98 {
99         /*
100          * Sanity check that we actually have something to match
101          * against. The input we get is a restrictive pattern,
102          * so technically a blank credential means "erase everything".
103          * But it is too easy to accidentally send this, since it is equivalent
104          * to empty input. So explicitly disallow it, and require that the
105          * pattern have some actual content to match.
106          */
107         if (c->protocol || c->host || c->path || c->username)
108                 rewrite_credential_file(fn, c, NULL);
109 }
110
111 static int lookup_credential(const char *fn, struct credential *c)
112 {
113         parse_credential_file(fn, c, print_entry, NULL);
114         return c->username && c->password;
115 }
116
117 int main(int argc, char **argv)
118 {
119         const char * const usage[] = {
120                 "git credential-store [options] <action>",
121                 NULL
122         };
123         const char *op;
124         struct credential c = CREDENTIAL_INIT;
125         char *file = NULL;
126         struct option options[] = {
127                 OPT_STRING(0, "file", &file, "path",
128                            "fetch and store credentials in <path>"),
129                 OPT_END()
130         };
131
132         umask(077);
133
134         argc = parse_options(argc, (const char **)argv, NULL, options, usage, 0);
135         if (argc != 1)
136                 usage_with_options(usage, options);
137         op = argv[0];
138
139         if (!file)
140                 file = expand_user_path("~/.git-credentials");
141         if (!file)
142                 die("unable to set up default path; use --file");
143
144         if (credential_read(&c, stdin) < 0)
145                 die("unable to read credential");
146
147         if (!strcmp(op, "get"))
148                 lookup_credential(file, &c);
149         else if (!strcmp(op, "erase"))
150                 remove_credential(file, &c);
151         else if (!strcmp(op, "store"))
152                 store_credential(file, &c);
153         else
154                 ; /* Ignore unknown operation. */
155
156         return 0;
157 }