refactor git_getpass into generic prompt function
[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 {
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         /* FIXME: for usernames, we should do something less magical that
125          * actually echoes the characters. However, we need to read from
126          * /dev/tty and not stdio, which is not portable (but getpass will do
127          * it for us). http.c uses the same workaround. */
128         r = git_getpass(prompt.buf);
129
130         strbuf_release(&desc);
131         strbuf_release(&prompt);
132         return xstrdup(r);
133 }
134
135 static void credential_getpass(struct credential *c)
136 {
137         if (!c->username)
138                 c->username = credential_ask_one("Username", c);
139         if (!c->password)
140                 c->password = credential_ask_one("Password", c);
141 }
142
143 int credential_read(struct credential *c, FILE *fp)
144 {
145         struct strbuf line = STRBUF_INIT;
146
147         while (strbuf_getline(&line, fp, '\n') != EOF) {
148                 char *key = line.buf;
149                 char *value = strchr(key, '=');
150
151                 if (!line.len)
152                         break;
153
154                 if (!value) {
155                         warning("invalid credential line: %s", key);
156                         strbuf_release(&line);
157                         return -1;
158                 }
159                 *value++ = '\0';
160
161                 if (!strcmp(key, "username")) {
162                         free(c->username);
163                         c->username = xstrdup(value);
164                 } else if (!strcmp(key, "password")) {
165                         free(c->password);
166                         c->password = xstrdup(value);
167                 } else if (!strcmp(key, "protocol")) {
168                         free(c->protocol);
169                         c->protocol = xstrdup(value);
170                 } else if (!strcmp(key, "host")) {
171                         free(c->host);
172                         c->host = xstrdup(value);
173                 } else if (!strcmp(key, "path")) {
174                         free(c->path);
175                         c->path = xstrdup(value);
176                 }
177                 /*
178                  * Ignore other lines; we don't know what they mean, but
179                  * this future-proofs us when later versions of git do
180                  * learn new lines, and the helpers are updated to match.
181                  */
182         }
183
184         strbuf_release(&line);
185         return 0;
186 }
187
188 static void credential_write_item(FILE *fp, const char *key, const char *value)
189 {
190         if (!value)
191                 return;
192         fprintf(fp, "%s=%s\n", key, value);
193 }
194
195 static void credential_write(const struct credential *c, FILE *fp)
196 {
197         credential_write_item(fp, "protocol", c->protocol);
198         credential_write_item(fp, "host", c->host);
199         credential_write_item(fp, "path", c->path);
200         credential_write_item(fp, "username", c->username);
201         credential_write_item(fp, "password", c->password);
202 }
203
204 static int run_credential_helper(struct credential *c,
205                                  const char *cmd,
206                                  int want_output)
207 {
208         struct child_process helper;
209         const char *argv[] = { NULL, NULL };
210         FILE *fp;
211
212         memset(&helper, 0, sizeof(helper));
213         argv[0] = cmd;
214         helper.argv = argv;
215         helper.use_shell = 1;
216         helper.in = -1;
217         if (want_output)
218                 helper.out = -1;
219         else
220                 helper.no_stdout = 1;
221
222         if (start_command(&helper) < 0)
223                 return -1;
224
225         fp = xfdopen(helper.in, "w");
226         credential_write(c, fp);
227         fclose(fp);
228
229         if (want_output) {
230                 int r;
231                 fp = xfdopen(helper.out, "r");
232                 r = credential_read(c, fp);
233                 fclose(fp);
234                 if (r < 0) {
235                         finish_command(&helper);
236                         return -1;
237                 }
238         }
239
240         if (finish_command(&helper))
241                 return -1;
242         return 0;
243 }
244
245 static int credential_do(struct credential *c, const char *helper,
246                          const char *operation)
247 {
248         struct strbuf cmd = STRBUF_INIT;
249         int r;
250
251         if (helper[0] == '!')
252                 strbuf_addstr(&cmd, helper + 1);
253         else if (is_absolute_path(helper))
254                 strbuf_addstr(&cmd, helper);
255         else
256                 strbuf_addf(&cmd, "git credential-%s", helper);
257
258         strbuf_addf(&cmd, " %s", operation);
259         r = run_credential_helper(c, cmd.buf, !strcmp(operation, "get"));
260
261         strbuf_release(&cmd);
262         return r;
263 }
264
265 void credential_fill(struct credential *c)
266 {
267         int i;
268
269         if (c->username && c->password)
270                 return;
271
272         credential_apply_config(c);
273
274         for (i = 0; i < c->helpers.nr; i++) {
275                 credential_do(c, c->helpers.items[i].string, "get");
276                 if (c->username && c->password)
277                         return;
278         }
279
280         credential_getpass(c);
281         if (!c->username && !c->password)
282                 die("unable to get password from user");
283 }
284
285 void credential_approve(struct credential *c)
286 {
287         int i;
288
289         if (c->approved)
290                 return;
291         if (!c->username || !c->password)
292                 return;
293
294         credential_apply_config(c);
295
296         for (i = 0; i < c->helpers.nr; i++)
297                 credential_do(c, c->helpers.items[i].string, "store");
298         c->approved = 1;
299 }
300
301 void credential_reject(struct credential *c)
302 {
303         int i;
304
305         credential_apply_config(c);
306
307         for (i = 0; i < c->helpers.nr; i++)
308                 credential_do(c, c->helpers.items[i].string, "erase");
309
310         free(c->username);
311         c->username = NULL;
312         free(c->password);
313         c->password = NULL;
314         c->approved = 0;
315 }
316
317 void credential_from_url(struct credential *c, const char *url)
318 {
319         const char *at, *colon, *cp, *slash, *host, *proto_end;
320
321         credential_clear(c);
322
323         /*
324          * Match one of:
325          *   (1) proto://<host>/...
326          *   (2) proto://<user>@<host>/...
327          *   (3) proto://<user>:<pass>@<host>/...
328          */
329         proto_end = strstr(url, "://");
330         if (!proto_end)
331                 return;
332         cp = proto_end + 3;
333         at = strchr(cp, '@');
334         colon = strchr(cp, ':');
335         slash = strchrnul(cp, '/');
336
337         if (!at || slash <= at) {
338                 /* Case (1) */
339                 host = cp;
340         }
341         else if (!colon || at <= colon) {
342                 /* Case (2) */
343                 c->username = url_decode_mem(cp, at - cp);
344                 host = at + 1;
345         } else {
346                 /* Case (3) */
347                 c->username = url_decode_mem(cp, colon - cp);
348                 c->password = url_decode_mem(colon + 1, at - (colon + 1));
349                 host = at + 1;
350         }
351
352         if (proto_end - url > 0)
353                 c->protocol = xmemdupz(url, proto_end - url);
354         if (slash - host > 0)
355                 c->host = url_decode_mem(host, slash - host);
356         /* Trim leading and trailing slashes from path */
357         while (*slash == '/')
358                 slash++;
359         if (*slash) {
360                 char *p;
361                 c->path = url_decode(slash);
362                 p = c->path + strlen(c->path) - 1;
363                 while (p > c->path && *p == '/')
364                         *p-- = '\0';
365         }
366 }