credential.c

   1 #include "cache.h"
   2 #include "config.h"
   3 #include "credential.h"
   4 #include "string-list.h"
   5 #include "run-command.h"
   6 #include "url.h"
   7 #include "prompt.h"
   8 #include "sigchain.h"
   9
  10 void credential_init(struct credential *c)
  11 {
  12         memset(c, 0, sizeof(*c));
  13         c->helpers.strdup_strings = 1;
  14 }
  15
  16 void credential_clear(struct credential *c)
  17 {
  18         free(c->protocol);
  19         free(c->host);
  20         free(c->path);
  21         free(c->username);
  22         free(c->password);
  23         string_list_clear(&c->helpers, 0);
  24
  25         credential_init(c);
  26 }
  27
  28 int credential_match(const struct credential *want,
  29                      const struct credential *have)
  30 {
  31 #define CHECK(x) (!want->x || (have->x && !strcmp(want->x, have->x)))
  32         return CHECK(protocol) &&
  33                CHECK(host) &&
  34                CHECK(path) &&
  35                CHECK(username);
  36 #undef CHECK
  37 }
  38
  39 static int credential_config_callback(const char *var, const char *value,
  40                                       void *data)
  41 {
  42         struct credential *c = data;
  43         const char *key, *dot;
  44
  45         if (!skip_prefix(var, "credential.", &key))
  46                 return 0;
  47
  48         if (!value)
  49                 return config_error_nonbool(var);
  50
  51         dot = strrchr(key, '.');
  52         if (dot) {
  53                 struct credential want = CREDENTIAL_INIT;
  54                 char *url = xmemdupz(key, dot - key);
  55                 int matched;
  56
  57                 credential_from_url(&want, url);
  58                 matched = credential_match(&want, c);
  59
  60                 credential_clear(&want);
  61                 free(url);
  62
  63                 if (!matched)
  64                         return 0;
  65                 key = dot + 1;
  66         }
  67
  68         if (!strcmp(key, "helper")) {
  69                 if (*value)
  70                         string_list_append(&c->helpers, value);
  71                 else
  72                         string_list_clear(&c->helpers, 0);
  73         } else if (!strcmp(key, "username")) {
  74                 if (!c->username)
  75                         c->username = xstrdup(value);
  76         }
  77         else if (!strcmp(key, "usehttppath"))
  78                 c->use_http_path = git_config_bool(var, value);
  79
  80         return 0;
  81 }
  82
  83 static int proto_is_http(const char *s)
  84 {
  85         if (!s)
  86                 return 0;
  87         return !strcmp(s, "https") || !strcmp(s, "http");
  88 }
  89
  90 static void credential_apply_config(struct credential *c)
  91 {
  92         if (c->configured)
  93                 return;
  94         git_config(credential_config_callback, c);
  95         c->configured = 1;
  96
  97         if (!c->use_http_path && proto_is_http(c->protocol)) {
  98                 FREE_AND_NULL(c->path);
  99         }
 100 }
 101
 102 static void credential_describe(struct credential *c, struct strbuf *out)
 103 {
 104         if (!c->protocol)
 105                 return;
 106         strbuf_addf(out, "%s://", c->protocol);
 107         if (c->username && *c->username)
 108                 strbuf_addf(out, "%s@", c->username);
 109         if (c->host)
 110                 strbuf_addstr(out, c->host);
 111         if (c->path)
 112                 strbuf_addf(out, "/%s", c->path);
 113 }
 114
 115 static char *credential_ask_one(const char *what, struct credential *c,
 116                                 int flags)
 117 {
 118         struct strbuf desc = STRBUF_INIT;
 119         struct strbuf prompt = STRBUF_INIT;
 120         char *r;
 121
 122         credential_describe(c, &desc);
 123         if (desc.len)
 124                 strbuf_addf(&prompt, "%s for '%s': ", what, desc.buf);
 125         else
 126                 strbuf_addf(&prompt, "%s: ", what);
 127
 128         r = git_prompt(prompt.buf, flags);
 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                                                  PROMPT_ASKPASS|PROMPT_ECHO);
 140         if (!c->password)
 141                 c->password = credential_ask_one("Password", c,
 142                                                  PROMPT_ASKPASS);
 143 }
 144
 145 int credential_read(struct credential *c, FILE *fp)
 146 {
 147         struct strbuf line = STRBUF_INIT;
 148
 149         while (strbuf_getline_lf(&line, fp) != EOF) {
 150                 char *key = line.buf;
 151                 char *value = strchr(key, '=');
 152
 153                 if (!line.len)
 154                         break;
 155
 156                 if (!value) {
 157                         warning("invalid credential line: %s", key);
 158                         strbuf_release(&line);
 159                         return -1;
 160                 }
 161                 *value++ = '\0';
 162
 163                 if (!strcmp(key, "username")) {
 164                         free(c->username);
 165                         c->username = xstrdup(value);
 166                 } else if (!strcmp(key, "password")) {
 167                         free(c->password);
 168                         c->password = xstrdup(value);
 169                 } else if (!strcmp(key, "protocol")) {
 170                         free(c->protocol);
 171                         c->protocol = xstrdup(value);
 172                 } else if (!strcmp(key, "host")) {
 173                         free(c->host);
 174                         c->host = xstrdup(value);
 175                 } else if (!strcmp(key, "path")) {
 176                         free(c->path);
 177                         c->path = xstrdup(value);
 178                 } else if (!strcmp(key, "url")) {
 179                         credential_from_url(c, value);
 180                 } else if (!strcmp(key, "quit")) {
 181                         c->quit = !!git_config_bool("quit", value);
 182                 }
 183                 /*
 184                  * Ignore other lines; we don't know what they mean, but
 185                  * this future-proofs us when later versions of git do
 186                  * learn new lines, and the helpers are updated to match.
 187                  */
 188         }
 189
 190         strbuf_release(&line);
 191         return 0;
 192 }
 193
 194 static void credential_write_item(FILE *fp, const char *key, const char *value)
 195 {
 196         if (!value)
 197                 return;
 198         fprintf(fp, "%s=%s\n", key, value);
 199 }
 200
 201 void credential_write(const struct credential *c, FILE *fp)
 202 {
 203         credential_write_item(fp, "protocol", c->protocol);
 204         credential_write_item(fp, "host", c->host);
 205         credential_write_item(fp, "path", c->path);
 206         credential_write_item(fp, "username", c->username);
 207         credential_write_item(fp, "password", c->password);
 208 }
 209
 210 static int run_credential_helper(struct credential *c,
 211                                  const char *cmd,
 212                                  int want_output)
 213 {
 214         struct child_process helper = CHILD_PROCESS_INIT;
 215         const char *argv[] = { NULL, NULL };
 216         FILE *fp;
 217
 218         argv[0] = cmd;
 219         helper.argv = argv;
 220         helper.use_shell = 1;
 221         helper.in = -1;
 222         if (want_output)
 223                 helper.out = -1;
 224         else
 225                 helper.no_stdout = 1;
 226
 227         if (start_command(&helper) < 0)
 228                 return -1;
 229
 230         fp = xfdopen(helper.in, "w");
 231         sigchain_push(SIGPIPE, SIG_IGN);
 232         credential_write(c, fp);
 233         fclose(fp);
 234         sigchain_pop(SIGPIPE);
 235
 236         if (want_output) {
 237                 int r;
 238                 fp = xfdopen(helper.out, "r");
 239                 r = credential_read(c, fp);
 240                 fclose(fp);
 241                 if (r < 0) {
 242                         finish_command(&helper);
 243                         return -1;
 244                 }
 245         }
 246
 247         if (finish_command(&helper))
 248                 return -1;
 249         return 0;
 250 }
 251
 252 static int credential_do(struct credential *c, const char *helper,
 253                          const char *operation)
 254 {
 255         struct strbuf cmd = STRBUF_INIT;
 256         int r;
 257
 258         if (helper[0] == '!')
 259                 strbuf_addstr(&cmd, helper + 1);
 260         else if (is_absolute_path(helper))
 261                 strbuf_addstr(&cmd, helper);
 262         else
 263                 strbuf_addf(&cmd, "git credential-%s", helper);
 264
 265         strbuf_addf(&cmd, " %s", operation);
 266         r = run_credential_helper(c, cmd.buf, !strcmp(operation, "get"));
 267
 268         strbuf_release(&cmd);
 269         return r;
 270 }
 271
 272 void credential_fill(struct credential *c)
 273 {
 274         int i;
 275
 276         if (c->username && c->password)
 277                 return;
 278
 279         credential_apply_config(c);
 280
 281         for (i = 0; i < c->helpers.nr; i++) {
 282                 credential_do(c, c->helpers.items[i].string, "get");
 283                 if (c->username && c->password)
 284                         return;
 285                 if (c->quit)
 286                         die("credential helper '%s' told us to quit",
 287                             c->helpers.items[i].string);
 288         }
 289
 290         credential_getpass(c);
 291         if (!c->username && !c->password)
 292                 die("unable to get password from user");
 293 }
 294
 295 void credential_approve(struct credential *c)
 296 {
 297         int i;
 298
 299         if (c->approved)
 300                 return;
 301         if (!c->username || !c->password)
 302                 return;
 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, "store");
 308         c->approved = 1;
 309 }
 310
 311 void credential_reject(struct credential *c)
 312 {
 313         int i;
 314
 315         credential_apply_config(c);
 316
 317         for (i = 0; i < c->helpers.nr; i++)
 318                 credential_do(c, c->helpers.items[i].string, "erase");
 319
 320         FREE_AND_NULL(c->username);
 321         FREE_AND_NULL(c->password);
 322         c->approved = 0;
 323 }
 324
 325 void credential_from_url(struct credential *c, const char *url)
 326 {
 327         const char *at, *colon, *cp, *slash, *host, *proto_end;
 328
 329         credential_clear(c);
 330
 331         /*
 332          * Match one of:
 333          *   (1) proto://<host>/...
 334          *   (2) proto://<user>@<host>/...
 335          *   (3) proto://<user>:<pass>@<host>/...
 336          */
 337         proto_end = strstr(url, "://");
 338         if (!proto_end)
 339                 return;
 340         cp = proto_end + 3;
 341         at = strchr(cp, '@');
 342         colon = strchr(cp, ':');
 343         slash = strchrnul(cp, '/');
 344
 345         if (!at || slash <= at) {
 346                 /* Case (1) */
 347                 host = cp;
 348         }
 349         else if (!colon || at <= colon) {
 350                 /* Case (2) */
 351                 c->username = url_decode_mem(cp, at - cp);
 352                 host = at + 1;
 353         } else {
 354                 /* Case (3) */
 355                 c->username = url_decode_mem(cp, colon - cp);
 356                 c->password = url_decode_mem(colon + 1, at - (colon + 1));
 357                 host = at + 1;
 358         }
 359
 360         if (proto_end - url > 0)
 361                 c->protocol = xmemdupz(url, proto_end - url);
 362         if (slash - host > 0)
 363                 c->host = url_decode_mem(host, slash - host);
 364         /* Trim leading and trailing slashes from path */
 365         while (*slash == '/')
 366                 slash++;
 367         if (*slash) {
 368                 char *p;
 369                 c->path = url_decode(slash);
 370                 p = c->path + strlen(c->path) - 1;
 371                 while (p > c->path && *p == '/')
 372                         *p-- = '\0';
 373         }
 374 }