strbuf: strbuf_read_file() should return ssize_t
[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         if (!skip_prefix(var, "credential.", &key))
44                 return 0;
45
46         if (!value)
47                 return config_error_nonbool(var);
48
49         dot = strrchr(key, '.');
50         if (dot) {
51                 struct credential want = CREDENTIAL_INIT;
52                 char *url = xmemdupz(key, dot - key);
53                 int matched;
54
55                 credential_from_url(&want, url);
56                 matched = credential_match(&want, c);
57
58                 credential_clear(&want);
59                 free(url);
60
61                 if (!matched)
62                         return 0;
63                 key = dot + 1;
64         }
65
66         if (!strcmp(key, "helper"))
67                 string_list_append(&c->helpers, value);
68         else if (!strcmp(key, "username")) {
69                 if (!c->username)
70                         c->username = xstrdup(value);
71         }
72         else if (!strcmp(key, "usehttppath"))
73                 c->use_http_path = git_config_bool(var, value);
74
75         return 0;
76 }
77
78 static int proto_is_http(const char *s)
79 {
80         if (!s)
81                 return 0;
82         return !strcmp(s, "https") || !strcmp(s, "http");
83 }
84
85 static void credential_apply_config(struct credential *c)
86 {
87         if (c->configured)
88                 return;
89         git_config(credential_config_callback, c);
90         c->configured = 1;
91
92         if (!c->use_http_path && proto_is_http(c->protocol)) {
93                 free(c->path);
94                 c->path = NULL;
95         }
96 }
97
98 static void credential_describe(struct credential *c, struct strbuf *out)
99 {
100         if (!c->protocol)
101                 return;
102         strbuf_addf(out, "%s://", c->protocol);
103         if (c->username && *c->username)
104                 strbuf_addf(out, "%s@", c->username);
105         if (c->host)
106                 strbuf_addstr(out, c->host);
107         if (c->path)
108                 strbuf_addf(out, "/%s", c->path);
109 }
110
111 static char *credential_ask_one(const char *what, struct credential *c,
112                                 int flags)
113 {
114         struct strbuf desc = STRBUF_INIT;
115         struct strbuf prompt = STRBUF_INIT;
116         char *r;
117
118         credential_describe(c, &desc);
119         if (desc.len)
120                 strbuf_addf(&prompt, "%s for '%s': ", what, desc.buf);
121         else
122                 strbuf_addf(&prompt, "%s: ", what);
123
124         r = git_prompt(prompt.buf, flags);
125
126         strbuf_release(&desc);
127         strbuf_release(&prompt);
128         return xstrdup(r);
129 }
130
131 static void credential_getpass(struct credential *c)
132 {
133         if (!c->username)
134                 c->username = credential_ask_one("Username", c,
135                                                  PROMPT_ASKPASS|PROMPT_ECHO);
136         if (!c->password)
137                 c->password = credential_ask_one("Password", c,
138                                                  PROMPT_ASKPASS);
139 }
140
141 int credential_read(struct credential *c, FILE *fp)
142 {
143         struct strbuf line = STRBUF_INIT;
144
145         while (strbuf_getline(&line, fp, '\n') != EOF) {
146                 char *key = line.buf;
147                 char *value = strchr(key, '=');
148
149                 if (!line.len)
150                         break;
151
152                 if (!value) {
153                         warning("invalid credential line: %s", key);
154                         strbuf_release(&line);
155                         return -1;
156                 }
157                 *value++ = '\0';
158
159                 if (!strcmp(key, "username")) {
160                         free(c->username);
161                         c->username = xstrdup(value);
162                 } else if (!strcmp(key, "password")) {
163                         free(c->password);
164                         c->password = xstrdup(value);
165                 } else if (!strcmp(key, "protocol")) {
166                         free(c->protocol);
167                         c->protocol = xstrdup(value);
168                 } else if (!strcmp(key, "host")) {
169                         free(c->host);
170                         c->host = xstrdup(value);
171                 } else if (!strcmp(key, "path")) {
172                         free(c->path);
173                         c->path = xstrdup(value);
174                 } else if (!strcmp(key, "url")) {
175                         credential_from_url(c, value);
176                 } else if (!strcmp(key, "quit")) {
177                         c->quit = !!git_config_bool("quit", value);
178                 }
179                 /*
180                  * Ignore other lines; we don't know what they mean, but
181                  * this future-proofs us when later versions of git do
182                  * learn new lines, and the helpers are updated to match.
183                  */
184         }
185
186         strbuf_release(&line);
187         return 0;
188 }
189
190 static void credential_write_item(FILE *fp, const char *key, const char *value)
191 {
192         if (!value)
193                 return;
194         fprintf(fp, "%s=%s\n", key, value);
195 }
196
197 void credential_write(const struct credential *c, FILE *fp)
198 {
199         credential_write_item(fp, "protocol", c->protocol);
200         credential_write_item(fp, "host", c->host);
201         credential_write_item(fp, "path", c->path);
202         credential_write_item(fp, "username", c->username);
203         credential_write_item(fp, "password", c->password);
204 }
205
206 static int run_credential_helper(struct credential *c,
207                                  const char *cmd,
208                                  int want_output)
209 {
210         struct child_process helper = CHILD_PROCESS_INIT;
211         const char *argv[] = { NULL, NULL };
212         FILE *fp;
213
214         argv[0] = cmd;
215         helper.argv = argv;
216         helper.use_shell = 1;
217         helper.in = -1;
218         if (want_output)
219                 helper.out = -1;
220         else
221                 helper.no_stdout = 1;
222
223         if (start_command(&helper) < 0)
224                 return -1;
225
226         fp = xfdopen(helper.in, "w");
227         credential_write(c, fp);
228         fclose(fp);
229
230         if (want_output) {
231                 int r;
232                 fp = xfdopen(helper.out, "r");
233                 r = credential_read(c, fp);
234                 fclose(fp);
235                 if (r < 0) {
236                         finish_command(&helper);
237                         return -1;
238                 }
239         }
240
241         if (finish_command(&helper))
242                 return -1;
243         return 0;
244 }
245
246 static int credential_do(struct credential *c, const char *helper,
247                          const char *operation)
248 {
249         struct strbuf cmd = STRBUF_INIT;
250         int r;
251
252         if (helper[0] == '!')
253                 strbuf_addstr(&cmd, helper + 1);
254         else if (is_absolute_path(helper))
255                 strbuf_addstr(&cmd, helper);
256         else
257                 strbuf_addf(&cmd, "git credential-%s", helper);
258
259         strbuf_addf(&cmd, " %s", operation);
260         r = run_credential_helper(c, cmd.buf, !strcmp(operation, "get"));
261
262         strbuf_release(&cmd);
263         return r;
264 }
265
266 void credential_fill(struct credential *c)
267 {
268         int i;
269
270         if (c->username && c->password)
271                 return;
272
273         credential_apply_config(c);
274
275         for (i = 0; i < c->helpers.nr; i++) {
276                 credential_do(c, c->helpers.items[i].string, "get");
277                 if (c->username && c->password)
278                         return;
279                 if (c->quit)
280                         die("credential helper '%s' told us to quit",
281                             c->helpers.items[i].string);
282         }
283
284         credential_getpass(c);
285         if (!c->username && !c->password)
286                 die("unable to get password from user");
287 }
288
289 void credential_approve(struct credential *c)
290 {
291         int i;
292
293         if (c->approved)
294                 return;
295         if (!c->username || !c->password)
296                 return;
297
298         credential_apply_config(c);
299
300         for (i = 0; i < c->helpers.nr; i++)
301                 credential_do(c, c->helpers.items[i].string, "store");
302         c->approved = 1;
303 }
304
305 void credential_reject(struct credential *c)
306 {
307         int i;
308
309         credential_apply_config(c);
310
311         for (i = 0; i < c->helpers.nr; i++)
312                 credential_do(c, c->helpers.items[i].string, "erase");
313
314         free(c->username);
315         c->username = NULL;
316         free(c->password);
317         c->password = NULL;
318         c->approved = 0;
319 }
320
321 void credential_from_url(struct credential *c, const char *url)
322 {
323         const char *at, *colon, *cp, *slash, *host, *proto_end;
324
325         credential_clear(c);
326
327         /*
328          * Match one of:
329          *   (1) proto://<host>/...
330          *   (2) proto://<user>@<host>/...
331          *   (3) proto://<user>:<pass>@<host>/...
332          */
333         proto_end = strstr(url, "://");
334         if (!proto_end)
335                 return;
336         cp = proto_end + 3;
337         at = strchr(cp, '@');
338         colon = strchr(cp, ':');
339         slash = strchrnul(cp, '/');
340
341         if (!at || slash <= at) {
342                 /* Case (1) */
343                 host = cp;
344         }
345         else if (!colon || at <= colon) {
346                 /* Case (2) */
347                 c->username = url_decode_mem(cp, at - cp);
348                 host = at + 1;
349         } else {
350                 /* Case (3) */
351                 c->username = url_decode_mem(cp, colon - cp);
352                 c->password = url_decode_mem(colon + 1, at - (colon + 1));
353                 host = at + 1;
354         }
355
356         if (proto_end - url > 0)
357                 c->protocol = xmemdupz(url, proto_end - url);
358         if (slash - host > 0)
359                 c->host = url_decode_mem(host, slash - host);
360         /* Trim leading and trailing slashes from path */
361         while (*slash == '/')
362                 slash++;
363         if (*slash) {
364                 char *p;
365                 c->path = url_decode(slash);
366                 p = c->path + strlen(c->path) - 1;
367                 while (p > c->path && *p == '/')
368                         *p-- = '\0';
369         }
370 }