git-remote-mediawiki: get rid of O(N^2) loop
[git] / credential.c
1 #include "cache.h"
2 #include "credential.h"
3 #include "string-list.h"
4 #include "run-command.h"
5 #include "url.h"
6 #include "prompt.h"
7
8 void credential_init(struct credential *c)
9 {
10         memset(c, 0, sizeof(*c));
11         c->helpers.strdup_strings = 1;
12 }
13
14 void credential_clear(struct credential *c)
15 {
16         free(c->protocol);
17         free(c->host);
18         free(c->path);
19         free(c->username);
20         free(c->password);
21         string_list_clear(&c->helpers, 0);
22
23         credential_init(c);
24 }
25
26 int credential_match(const struct credential *want,
27                      const struct credential *have)
28 {
29 #define CHECK(x) (!want->x || (have->x && !strcmp(want->x, have->x)))
30         return CHECK(protocol) &&
31                CHECK(host) &&
32                CHECK(path) &&
33                CHECK(username);
34 #undef CHECK
35 }
36
37 static int credential_config_callback(const char *var, const char *value,
38                                       void *data)
39 {
40         struct credential *c = data;
41         const char *key, *dot;
42
43         key = skip_prefix(var, "credential.");
44         if (!key)
45                 return 0;
46
47         if (!value)
48                 return config_error_nonbool(var);
49
50         dot = strrchr(key, '.');
51         if (dot) {
52                 struct credential want = CREDENTIAL_INIT;
53                 char *url = xmemdupz(key, dot - key);
54                 int matched;
55
56                 credential_from_url(&want, url);
57                 matched = credential_match(&want, c);
58
59                 credential_clear(&want);
60                 free(url);
61
62                 if (!matched)
63                         return 0;
64                 key = dot + 1;
65         }
66
67         if (!strcmp(key, "helper"))
68                 string_list_append(&c->helpers, value);
69         else if (!strcmp(key, "username")) {
70                 if (!c->username)
71                         c->username = xstrdup(value);
72         }
73         else if (!strcmp(key, "usehttppath"))
74                 c->use_http_path = git_config_bool(var, value);
75
76         return 0;
77 }
78
79 static int proto_is_http(const char *s)
80 {
81         if (!s)
82                 return 0;
83         return !strcmp(s, "https") || !strcmp(s, "http");
84 }
85
86 static void credential_apply_config(struct credential *c)
87 {
88         if (c->configured)
89                 return;
90         git_config(credential_config_callback, c);
91         c->configured = 1;
92
93         if (!c->use_http_path && proto_is_http(c->protocol)) {
94                 free(c->path);
95                 c->path = NULL;
96         }
97 }
98
99 static void credential_describe(struct credential *c, struct strbuf *out)
100 {
101         if (!c->protocol)
102                 return;
103         strbuf_addf(out, "%s://", c->protocol);
104         if (c->username && *c->username)
105                 strbuf_addf(out, "%s@", c->username);
106         if (c->host)
107                 strbuf_addstr(out, c->host);
108         if (c->path)
109                 strbuf_addf(out, "/%s", c->path);
110 }
111
112 static char *credential_ask_one(const char *what, struct credential *c,
113                                 int flags)
114 {
115         struct strbuf desc = STRBUF_INIT;
116         struct strbuf prompt = STRBUF_INIT;
117         char *r;
118
119         credential_describe(c, &desc);
120         if (desc.len)
121                 strbuf_addf(&prompt, "%s for '%s': ", what, desc.buf);
122         else
123                 strbuf_addf(&prompt, "%s: ", what);
124
125         r = git_prompt(prompt.buf, flags);
126
127         strbuf_release(&desc);
128         strbuf_release(&prompt);
129         return xstrdup(r);
130 }
131
132 static void credential_getpass(struct credential *c)
133 {
134         if (!c->username)
135                 c->username = credential_ask_one("Username", c,
136                                                  PROMPT_ASKPASS|PROMPT_ECHO);
137         if (!c->password)
138                 c->password = credential_ask_one("Password", c,
139                                                  PROMPT_ASKPASS);
140 }
141
142 int credential_read(struct credential *c, FILE *fp)
143 {
144         struct strbuf line = STRBUF_INIT;
145
146         while (strbuf_getline(&line, fp, '\n') != EOF) {
147                 char *key = line.buf;
148                 char *value = strchr(key, '=');
149
150                 if (!line.len)
151                         break;
152
153                 if (!value) {
154                         warning("invalid credential line: %s", key);
155                         strbuf_release(&line);
156                         return -1;
157                 }
158                 *value++ = '\0';
159
160                 if (!strcmp(key, "username")) {
161                         free(c->username);
162                         c->username = xstrdup(value);
163                 } else if (!strcmp(key, "password")) {
164                         free(c->password);
165                         c->password = xstrdup(value);
166                 } else if (!strcmp(key, "protocol")) {
167                         free(c->protocol);
168                         c->protocol = xstrdup(value);
169                 } else if (!strcmp(key, "host")) {
170                         free(c->host);
171                         c->host = xstrdup(value);
172                 } else if (!strcmp(key, "path")) {
173                         free(c->path);
174                         c->path = xstrdup(value);
175                 }
176                 /*
177                  * Ignore other lines; we don't know what they mean, but
178                  * this future-proofs us when later versions of git do
179                  * learn new lines, and the helpers are updated to match.
180                  */
181         }
182
183         strbuf_release(&line);
184         return 0;
185 }
186
187 static void credential_write_item(FILE *fp, const char *key, const char *value)
188 {
189         if (!value)
190                 return;
191         fprintf(fp, "%s=%s\n", key, value);
192 }
193
194 void credential_write(const struct credential *c, FILE *fp)
195 {
196         credential_write_item(fp, "protocol", c->protocol);
197         credential_write_item(fp, "host", c->host);
198         credential_write_item(fp, "path", c->path);
199         credential_write_item(fp, "username", c->username);
200         credential_write_item(fp, "password", c->password);
201 }
202
203 static int run_credential_helper(struct credential *c,
204                                  const char *cmd,
205                                  int want_output)
206 {
207         struct child_process helper;
208         const char *argv[] = { NULL, NULL };
209         FILE *fp;
210
211         memset(&helper, 0, sizeof(helper));
212         argv[0] = cmd;
213         helper.argv = argv;
214         helper.use_shell = 1;
215         helper.in = -1;
216         if (want_output)
217                 helper.out = -1;
218         else
219                 helper.no_stdout = 1;
220
221         if (start_command(&helper) < 0)
222                 return -1;
223
224         fp = xfdopen(helper.in, "w");
225         credential_write(c, fp);
226         fclose(fp);
227
228         if (want_output) {
229                 int r;
230                 fp = xfdopen(helper.out, "r");
231                 r = credential_read(c, fp);
232                 fclose(fp);
233                 if (r < 0) {
234                         finish_command(&helper);
235                         return -1;
236                 }
237         }
238
239         if (finish_command(&helper))
240                 return -1;
241         return 0;
242 }
243
244 static int credential_do(struct credential *c, const char *helper,
245                          const char *operation)
246 {
247         struct strbuf cmd = STRBUF_INIT;
248         int r;
249
250         if (helper[0] == '!')
251                 strbuf_addstr(&cmd, helper + 1);
252         else if (is_absolute_path(helper))
253                 strbuf_addstr(&cmd, helper);
254         else
255                 strbuf_addf(&cmd, "git credential-%s", helper);
256
257         strbuf_addf(&cmd, " %s", operation);
258         r = run_credential_helper(c, cmd.buf, !strcmp(operation, "get"));
259
260         strbuf_release(&cmd);
261         return r;
262 }
263
264 void credential_fill(struct credential *c)
265 {
266         int i;
267
268         if (c->username && c->password)
269                 return;
270
271         credential_apply_config(c);
272
273         for (i = 0; i < c->helpers.nr; i++) {
274                 credential_do(c, c->helpers.items[i].string, "get");
275                 if (c->username && c->password)
276                         return;
277         }
278
279         credential_getpass(c);
280         if (!c->username && !c->password)
281                 die("unable to get password from user");
282 }
283
284 void credential_approve(struct credential *c)
285 {
286         int i;
287
288         if (c->approved)
289                 return;
290         if (!c->username || !c->password)
291                 return;
292
293         credential_apply_config(c);
294
295         for (i = 0; i < c->helpers.nr; i++)
296                 credential_do(c, c->helpers.items[i].string, "store");
297         c->approved = 1;
298 }
299
300 void credential_reject(struct credential *c)
301 {
302         int i;
303
304         credential_apply_config(c);
305
306         for (i = 0; i < c->helpers.nr; i++)
307                 credential_do(c, c->helpers.items[i].string, "erase");
308
309         free(c->username);
310         c->username = NULL;
311         free(c->password);
312         c->password = NULL;
313         c->approved = 0;
314 }
315
316 void credential_from_url(struct credential *c, const char *url)
317 {
318         const char *at, *colon, *cp, *slash, *host, *proto_end;
319
320         credential_clear(c);
321
322         /*
323          * Match one of:
324          *   (1) proto://<host>/...
325          *   (2) proto://<user>@<host>/...
326          *   (3) proto://<user>:<pass>@<host>/...
327          */
328         proto_end = strstr(url, "://");
329         if (!proto_end)
330                 return;
331         cp = proto_end + 3;
332         at = strchr(cp, '@');
333         colon = strchr(cp, ':');
334         slash = strchrnul(cp, '/');
335
336         if (!at || slash <= at) {
337                 /* Case (1) */
338                 host = cp;
339         }
340         else if (!colon || at <= colon) {
341                 /* Case (2) */
342                 c->username = url_decode_mem(cp, at - cp);
343                 host = at + 1;
344         } else {
345                 /* Case (3) */
346                 c->username = url_decode_mem(cp, colon - cp);
347                 c->password = url_decode_mem(colon + 1, at - (colon + 1));
348                 host = at + 1;
349         }
350
351         if (proto_end - url > 0)
352                 c->protocol = xmemdupz(url, proto_end - url);
353         if (slash - host > 0)
354                 c->host = url_decode_mem(host, slash - host);
355         /* Trim leading and trailing slashes from path */
356         while (*slash == '/')
357                 slash++;
358         if (*slash) {
359                 char *p;
360                 c->path = url_decode(slash);
361                 p = c->path + strlen(c->path) - 1;
362                 while (p > c->path && *p == '/')
363                         *p-- = '\0';
364         }
365 }