git.oblomov.eu Git - git/blob - 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
   9 void credential_init(struct credential *c)
  10 {
  11         memset(c, 0, sizeof(*c));
  12         c->helpers.strdup_strings = 1;
  13 }
  14
  15 void credential_clear(struct credential *c)
  16 {
  17         free(c->protocol);
  18         free(c->host);
  19         free(c->path);
  20         free(c->username);
  21         free(c->password);
  22         string_list_clear(&c->helpers, 0);
  23
  24         credential_init(c);
  25 }
  26
  27 int credential_match(const struct credential *want,
  28                      const struct credential *have)
  29 {
  30 #define CHECK(x) (!want->x || (have->x && !strcmp(want->x, have->x)))
  31         return CHECK(protocol) &&
  32                CHECK(host) &&
  33                CHECK(path) &&
  34                CHECK(username);
  35 #undef CHECK
  36 }
  37
  38
  39 static int credential_from_potentially_partial_url(struct credential *c,
  40                                                    const char *url);
  41
  42 static int credential_config_callback(const char *var, const char *value,
  43                                       void *data)
  44 {
  45         struct credential *c = data;
  46         const char *key, *dot;
  47
  48         if (!skip_prefix(var, "credential.", &key))
  49                 return 0;
  50
  51         if (!value)
  52                 return config_error_nonbool(var);
  53
  54         dot = strrchr(key, '.');
  55         if (dot) {
  56                 struct credential want = CREDENTIAL_INIT;
  57                 char *url = xmemdupz(key, dot - key);
  58                 int matched;
  59
  60                 if (credential_from_potentially_partial_url(&want, url) < 0) {
  61                         warning(_("skipping credential lookup for key: %s"),
  62                                 var);
  63                         credential_clear(&want);
  64                         free(url);
  65                         return 0;
  66                 }
  67                 matched = credential_match(&want, c);
  68
  69                 credential_clear(&want);
  70                 free(url);
  71
  72                 if (!matched)
  73                         return 0;
  74                 key = dot + 1;
  75         }
  76
  77         if (!strcmp(key, "helper")) {
  78                 if (*value)
  79                         string_list_append(&c->helpers, value);
  80                 else
  81                         string_list_clear(&c->helpers, 0);
  82         } else if (!strcmp(key, "username")) {
  83                 if (!c->username)
  84                         c->username = xstrdup(value);
  85         }
  86         else if (!strcmp(key, "usehttppath"))
  87                 c->use_http_path = git_config_bool(var, value);
  88
  89         return 0;
  90 }
  91
  92 static int proto_is_http(const char *s)
  93 {
  94         if (!s)
  95                 return 0;
  96         return !strcmp(s, "https") || !strcmp(s, "http");
  97 }
  98
  99 static void credential_apply_config(struct credential *c)
 100 {
 101         if (!c->host)
 102                 die(_("refusing to work with credential missing host field"));
 103         if (!c->protocol)
 104                 die(_("refusing to work with credential missing protocol field"));
 105
 106         if (c->configured)
 107                 return;
 108         git_config(credential_config_callback, c);
 109         c->configured = 1;
 110
 111         if (!c->use_http_path && proto_is_http(c->protocol)) {
 112                 FREE_AND_NULL(c->path);
 113         }
 114 }
 115
 116 static void credential_describe(struct credential *c, struct strbuf *out)
 117 {
 118         if (!c->protocol)
 119                 return;
 120         strbuf_addf(out, "%s://", c->protocol);
 121         if (c->username && *c->username)
 122                 strbuf_addf(out, "%s@", c->username);
 123         if (c->host)
 124                 strbuf_addstr(out, c->host);
 125         if (c->path)
 126                 strbuf_addf(out, "/%s", c->path);
 127 }
 128
 129 static char *credential_ask_one(const char *what, struct credential *c,
 130                                 int flags)
 131 {
 132         struct strbuf desc = STRBUF_INIT;
 133         struct strbuf prompt = STRBUF_INIT;
 134         char *r;
 135
 136         credential_describe(c, &desc);
 137         if (desc.len)
 138                 strbuf_addf(&prompt, "%s for '%s': ", what, desc.buf);
 139         else
 140                 strbuf_addf(&prompt, "%s: ", what);
 141
 142         r = git_prompt(prompt.buf, flags);
 143
 144         strbuf_release(&desc);
 145         strbuf_release(&prompt);
 146         return xstrdup(r);
 147 }
 148
 149 static void credential_getpass(struct credential *c)
 150 {
 151         if (!c->username)
 152                 c->username = credential_ask_one("Username", c,
 153                                                  PROMPT_ASKPASS|PROMPT_ECHO);
 154         if (!c->password)
 155                 c->password = credential_ask_one("Password", c,
 156                                                  PROMPT_ASKPASS);
 157 }
 158
 159 int credential_read(struct credential *c, FILE *fp)
 160 {
 161         struct strbuf line = STRBUF_INIT;
 162
 163         while (strbuf_getline_lf(&line, fp) != EOF) {
 164                 char *key = line.buf;
 165                 char *value = strchr(key, '=');
 166
 167                 if (!line.len)
 168                         break;
 169
 170                 if (!value) {
 171                         warning("invalid credential line: %s", key);
 172                         strbuf_release(&line);
 173                         return -1;
 174                 }
 175                 *value++ = '\0';
 176
 177                 if (!strcmp(key, "username")) {
 178                         free(c->username);
 179                         c->username = xstrdup(value);
 180                 } else if (!strcmp(key, "password")) {
 181                         free(c->password);
 182                         c->password = xstrdup(value);
 183                 } else if (!strcmp(key, "protocol")) {
 184                         free(c->protocol);
 185                         c->protocol = xstrdup(value);
 186                 } else if (!strcmp(key, "host")) {
 187                         free(c->host);
 188                         c->host = xstrdup(value);
 189                 } else if (!strcmp(key, "path")) {
 190                         free(c->path);
 191                         c->path = xstrdup(value);
 192                 } else if (!strcmp(key, "url")) {
 193                         credential_from_url(c, value);
 194                 } else if (!strcmp(key, "quit")) {
 195                         c->quit = !!git_config_bool("quit", value);
 196                 }
 197                 /*
 198                  * Ignore other lines; we don't know what they mean, but
 199                  * this future-proofs us when later versions of git do
 200                  * learn new lines, and the helpers are updated to match.
 201                  */
 202         }
 203
 204         strbuf_release(&line);
 205         return 0;
 206 }
 207
 208 static void credential_write_item(FILE *fp, const char *key, const char *value,
 209                                   int required)
 210 {
 211         if (!value && required)
 212                 BUG("credential value for %s is missing", key);
 213         if (!value)
 214                 return;
 215         if (strchr(value, '\n'))
 216                 die("credential value for %s contains newline", key);
 217         fprintf(fp, "%s=%s\n", key, value);
 218 }
 219
 220 void credential_write(const struct credential *c, FILE *fp)
 221 {
 222         credential_write_item(fp, "protocol", c->protocol, 1);
 223         credential_write_item(fp, "host", c->host, 1);
 224         credential_write_item(fp, "path", c->path, 0);
 225         credential_write_item(fp, "username", c->username, 0);
 226         credential_write_item(fp, "password", c->password, 0);
 227 }
 228
 229 static int run_credential_helper(struct credential *c,
 230                                  const char *cmd,
 231                                  int want_output)
 232 {
 233         struct child_process helper = CHILD_PROCESS_INIT;
 234         const char *argv[] = { NULL, NULL };
 235         FILE *fp;
 236
 237         argv[0] = cmd;
 238         helper.argv = argv;
 239         helper.use_shell = 1;
 240         helper.in = -1;
 241         if (want_output)
 242                 helper.out = -1;
 243         else
 244                 helper.no_stdout = 1;
 245
 246         if (start_command(&helper) < 0)
 247                 return -1;
 248
 249         fp = xfdopen(helper.in, "w");
 250         credential_write(c, fp);
 251         fclose(fp);
 252
 253         if (want_output) {
 254                 int r;
 255                 fp = xfdopen(helper.out, "r");
 256                 r = credential_read(c, fp);
 257                 fclose(fp);
 258                 if (r < 0) {
 259                         finish_command(&helper);
 260                         return -1;
 261                 }
 262         }
 263
 264         if (finish_command(&helper))
 265                 return -1;
 266         return 0;
 267 }
 268
 269 static int credential_do(struct credential *c, const char *helper,
 270                          const char *operation)
 271 {
 272         struct strbuf cmd = STRBUF_INIT;
 273         int r;
 274
 275         if (helper[0] == '!')
 276                 strbuf_addstr(&cmd, helper + 1);
 277         else if (is_absolute_path(helper))
 278                 strbuf_addstr(&cmd, helper);
 279         else
 280                 strbuf_addf(&cmd, "git credential-%s", helper);
 281
 282         strbuf_addf(&cmd, " %s", operation);
 283         r = run_credential_helper(c, cmd.buf, !strcmp(operation, "get"));
 284
 285         strbuf_release(&cmd);
 286         return r;
 287 }
 288
 289 void credential_fill(struct credential *c)
 290 {
 291         int i;
 292
 293         if (c->username && c->password)
 294                 return;
 295
 296         credential_apply_config(c);
 297
 298         for (i = 0; i < c->helpers.nr; i++) {
 299                 credential_do(c, c->helpers.items[i].string, "get");
 300                 if (c->username && c->password)
 301                         return;
 302                 if (c->quit)
 303                         die("credential helper '%s' told us to quit",
 304                             c->helpers.items[i].string);
 305         }
 306
 307         credential_getpass(c);
 308         if (!c->username && !c->password)
 309                 die("unable to get password from user");
 310 }
 311
 312 void credential_approve(struct credential *c)
 313 {
 314         int i;
 315
 316         if (c->approved)
 317                 return;
 318         if (!c->username || !c->password)
 319                 return;
 320
 321         credential_apply_config(c);
 322
 323         for (i = 0; i < c->helpers.nr; i++)
 324                 credential_do(c, c->helpers.items[i].string, "store");
 325         c->approved = 1;
 326 }
 327
 328 void credential_reject(struct credential *c)
 329 {
 330         int i;
 331
 332         credential_apply_config(c);
 333
 334         for (i = 0; i < c->helpers.nr; i++)
 335                 credential_do(c, c->helpers.items[i].string, "erase");
 336
 337         FREE_AND_NULL(c->username);
 338         FREE_AND_NULL(c->password);
 339         c->approved = 0;
 340 }
 341
 342 static int check_url_component(const char *url, int quiet,
 343                                const char *name, const char *value)
 344 {
 345         if (!value)
 346                 return 0;
 347         if (!strchr(value, '\n'))
 348                 return 0;
 349
 350         if (!quiet)
 351                 warning(_("url contains a newline in its %s component: %s"),
 352                         name, url);
 353         return -1;
 354 }
 355
 356 /*
 357  * Potentially-partial URLs can, but do not have to, contain
 358  *
 359  * - a protocol (or scheme) of the form "<protocol>://"
 360  *
 361  * - a host name (the part after the protocol and before the first slash after
 362  *   that, if any)
 363  *
 364  * - a user name and potentially a password (as "<user>[:<password>]@" part of
 365  *   the host name)
 366  *
 367  * - a path (the part after the host name, if any, starting with the slash)
 368  *
 369  * Missing parts will be left unset in `struct credential`. Thus, `https://`
 370  * will have only the `protocol` set, `example.com` only the host name, and
 371  * `/git` only the path.
 372  *
 373  * Note that an empty host name in an otherwise fully-qualified URL (e.g.
 374  * `cert:///path/to/cert.pem`) will be treated as unset if we expect the URL to
 375  * be potentially partial, and only then (otherwise, the empty string is used).
 376  *
 377  * The credential_from_url() function does not allow partial URLs.
 378  */
 379 static int credential_from_url_1(struct credential *c, const char *url,
 380                                  int allow_partial_url, int quiet)
 381 {
 382         const char *at, *colon, *cp, *slash, *host, *proto_end;
 383
 384         credential_clear(c);
 385
 386         /*
 387          * Match one of:
 388          *   (1) proto://<host>/...
 389          *   (2) proto://<user>@<host>/...
 390          *   (3) proto://<user>:<pass>@<host>/...
 391          */
 392         proto_end = strstr(url, "://");
 393         if (!allow_partial_url && (!proto_end || proto_end == url)) {
 394                 if (!quiet)
 395                         warning(_("url has no scheme: %s"), url);
 396                 return -1;
 397         }
 398         cp = proto_end ? proto_end + 3 : url;
 399         at = strchr(cp, '@');
 400         colon = strchr(cp, ':');
 401         slash = strchrnul(cp, '/');
 402
 403         if (!at || slash <= at) {
 404                 /* Case (1) */
 405                 host = cp;
 406         }
 407         else if (!colon || at <= colon) {
 408                 /* Case (2) */
 409                 c->username = url_decode_mem(cp, at - cp);
 410                 host = at + 1;
 411         } else {
 412                 /* Case (3) */
 413                 c->username = url_decode_mem(cp, colon - cp);
 414                 c->password = url_decode_mem(colon + 1, at - (colon + 1));
 415                 host = at + 1;
 416         }
 417
 418         if (proto_end && proto_end - url > 0)
 419                 c->protocol = xmemdupz(url, proto_end - url);
 420         if (!allow_partial_url || slash - host > 0)
 421                 c->host = url_decode_mem(host, slash - host);
 422         /* Trim leading and trailing slashes from path */
 423         while (*slash == '/')
 424                 slash++;
 425         if (*slash) {
 426                 char *p;
 427                 c->path = url_decode(slash);
 428                 p = c->path + strlen(c->path) - 1;
 429                 while (p > c->path && *p == '/')
 430                         *p-- = '\0';
 431         }
 432
 433         if (check_url_component(url, quiet, "username", c->username) < 0 ||
 434             check_url_component(url, quiet, "password", c->password) < 0 ||
 435             check_url_component(url, quiet, "protocol", c->protocol) < 0 ||
 436             check_url_component(url, quiet, "host", c->host) < 0 ||
 437             check_url_component(url, quiet, "path", c->path) < 0)
 438                 return -1;
 439
 440         return 0;
 441 }
 442
 443 static int credential_from_potentially_partial_url(struct credential *c,
 444                                                    const char *url)
 445 {
 446         return credential_from_url_1(c, url, 1, 0);
 447 }
 448
 449 int credential_from_url_gently(struct credential *c, const char *url, int quiet)
 450 {
 451         return credential_from_url_1(c, url, 0, quiet);
 452 }
 453
 454 void credential_from_url(struct credential *c, const char *url)
 455 {
 456         if (credential_from_url_gently(c, url, 0) < 0)
 457                 die(_("credential url cannot be parsed: %s"), url);
 458 }