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 static int credential_config_callback(const char *var, const char *value,
  39                                       void *data)
  40 {
  41         struct credential *c = data;
  42         const char *key, *dot;
  43
  44         if (!skip_prefix(var, "credential.", &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                 if (*value)
  69                         string_list_append(&c->helpers, value);
  70                 else
  71                         string_list_clear(&c->helpers, 0);
  72         } else if (!strcmp(key, "username")) {
  73                 if (!c->username)
  74                         c->username = xstrdup(value);
  75         }
  76         else if (!strcmp(key, "usehttppath"))
  77                 c->use_http_path = git_config_bool(var, value);
  78
  79         return 0;
  80 }
  81
  82 static int proto_is_http(const char *s)
  83 {
  84         if (!s)
  85                 return 0;
  86         return !strcmp(s, "https") || !strcmp(s, "http");
  87 }
  88
  89 static void credential_apply_config(struct credential *c)
  90 {
  91         if (c->configured)
  92                 return;
  93         git_config(credential_config_callback, c);
  94         c->configured = 1;
  95
  96         if (!c->use_http_path && proto_is_http(c->protocol)) {
  97                 FREE_AND_NULL(c->path);
  98         }
  99 }
 100
 101 static void credential_describe(struct credential *c, struct strbuf *out)
 102 {
 103         if (!c->protocol)
 104                 return;
 105         strbuf_addf(out, "%s://", c->protocol);
 106         if (c->username && *c->username)
 107                 strbuf_addf(out, "%s@", c->username);
 108         if (c->host)
 109                 strbuf_addstr(out, c->host);
 110         if (c->path)
 111                 strbuf_addf(out, "/%s", c->path);
 112 }
 113
 114 static char *credential_ask_one(const char *what, struct credential *c,
 115                                 int flags)
 116 {
 117         struct strbuf desc = STRBUF_INIT;
 118         struct strbuf prompt = STRBUF_INIT;
 119         char *r;
 120
 121         credential_describe(c, &desc);
 122         if (desc.len)
 123                 strbuf_addf(&prompt, "%s for '%s': ", what, desc.buf);
 124         else
 125                 strbuf_addf(&prompt, "%s: ", what);
 126
 127         r = git_prompt(prompt.buf, flags);
 128
 129         strbuf_release(&desc);
 130         strbuf_release(&prompt);
 131         return xstrdup(r);
 132 }
 133
 134 static void credential_getpass(struct credential *c)
 135 {
 136         if (!c->username)
 137                 c->username = credential_ask_one("Username", c,
 138                                                  PROMPT_ASKPASS|PROMPT_ECHO);
 139         if (!c->password)
 140                 c->password = credential_ask_one("Password", c,
 141                                                  PROMPT_ASKPASS);
 142 }
 143
 144 int credential_read(struct credential *c, FILE *fp)
 145 {
 146         struct strbuf line = STRBUF_INIT;
 147
 148         while (strbuf_getline_lf(&line, fp) != EOF) {
 149                 char *key = line.buf;
 150                 char *value = strchr(key, '=');
 151
 152                 if (!line.len)
 153                         break;
 154
 155                 if (!value) {
 156                         warning("invalid credential line: %s", key);
 157                         strbuf_release(&line);
 158                         return -1;
 159                 }
 160                 *value++ = '\0';
 161
 162                 if (!strcmp(key, "username")) {
 163                         free(c->username);
 164                         c->username = xstrdup(value);
 165                 } else if (!strcmp(key, "password")) {
 166                         free(c->password);
 167                         c->password = xstrdup(value);
 168                 } else if (!strcmp(key, "protocol")) {
 169                         free(c->protocol);
 170                         c->protocol = xstrdup(value);
 171                 } else if (!strcmp(key, "host")) {
 172                         free(c->host);
 173                         c->host = xstrdup(value);
 174                 } else if (!strcmp(key, "path")) {
 175                         free(c->path);
 176                         c->path = xstrdup(value);
 177                 } else if (!strcmp(key, "url")) {
 178                         credential_from_url(c, value);
 179                 } else if (!strcmp(key, "quit")) {
 180                         c->quit = !!git_config_bool("quit", value);
 181                 }
 182                 /*
 183                  * Ignore other lines; we don't know what they mean, but
 184                  * this future-proofs us when later versions of git do
 185                  * learn new lines, and the helpers are updated to match.
 186                  */
 187         }
 188
 189         strbuf_release(&line);
 190         return 0;
 191 }
 192
 193 static void credential_write_item(FILE *fp, const char *key, const char *value)
 194 {
 195         if (!value)
 196                 return;
 197         if (strchr(value, '\n'))
 198                 die("credential value for %s contains newline", key);
 199         fprintf(fp, "%s=%s\n", key, value);
 200 }
 201
 202 void credential_write(const struct credential *c, FILE *fp)
 203 {
 204         credential_write_item(fp, "protocol", c->protocol);
 205         credential_write_item(fp, "host", c->host);
 206         credential_write_item(fp, "path", c->path);
 207         credential_write_item(fp, "username", c->username);
 208         credential_write_item(fp, "password", c->password);
 209 }
 210
 211 static int run_credential_helper(struct credential *c,
 212                                  const char *cmd,
 213                                  int want_output)
 214 {
 215         struct child_process helper = CHILD_PROCESS_INIT;
 216         const char *argv[] = { NULL, NULL };
 217         FILE *fp;
 218
 219         argv[0] = cmd;
 220         helper.argv = argv;
 221         helper.use_shell = 1;
 222         helper.in = -1;
 223         if (want_output)
 224                 helper.out = -1;
 225         else
 226                 helper.no_stdout = 1;
 227
 228         if (start_command(&helper) < 0)
 229                 return -1;
 230
 231         fp = xfdopen(helper.in, "w");
 232         credential_write(c, fp);
 233         fclose(fp);
 234
 235         if (want_output) {
 236                 int r;
 237                 fp = xfdopen(helper.out, "r");
 238                 r = credential_read(c, fp);
 239                 fclose(fp);
 240                 if (r < 0) {
 241                         finish_command(&helper);
 242                         return -1;
 243                 }
 244         }
 245
 246         if (finish_command(&helper))
 247                 return -1;
 248         return 0;
 249 }
 250
 251 static int credential_do(struct credential *c, const char *helper,
 252                          const char *operation)
 253 {
 254         struct strbuf cmd = STRBUF_INIT;
 255         int r;
 256
 257         if (helper[0] == '!')
 258                 strbuf_addstr(&cmd, helper + 1);
 259         else if (is_absolute_path(helper))
 260                 strbuf_addstr(&cmd, helper);
 261         else
 262                 strbuf_addf(&cmd, "git credential-%s", helper);
 263
 264         strbuf_addf(&cmd, " %s", operation);
 265         r = run_credential_helper(c, cmd.buf, !strcmp(operation, "get"));
 266
 267         strbuf_release(&cmd);
 268         return r;
 269 }
 270
 271 void credential_fill(struct credential *c)
 272 {
 273         int i;
 274
 275         if (c->username && c->password)
 276                 return;
 277
 278         credential_apply_config(c);
 279
 280         for (i = 0; i < c->helpers.nr; i++) {
 281                 credential_do(c, c->helpers.items[i].string, "get");
 282                 if (c->username && c->password)
 283                         return;
 284                 if (c->quit)
 285                         die("credential helper '%s' told us to quit",
 286                             c->helpers.items[i].string);
 287         }
 288
 289         credential_getpass(c);
 290         if (!c->username && !c->password)
 291                 die("unable to get password from user");
 292 }
 293
 294 void credential_approve(struct credential *c)
 295 {
 296         int i;
 297
 298         if (c->approved)
 299                 return;
 300         if (!c->username || !c->password)
 301                 return;
 302
 303         credential_apply_config(c);
 304
 305         for (i = 0; i < c->helpers.nr; i++)
 306                 credential_do(c, c->helpers.items[i].string, "store");
 307         c->approved = 1;
 308 }
 309
 310 void credential_reject(struct credential *c)
 311 {
 312         int i;
 313
 314         credential_apply_config(c);
 315
 316         for (i = 0; i < c->helpers.nr; i++)
 317                 credential_do(c, c->helpers.items[i].string, "erase");
 318
 319         FREE_AND_NULL(c->username);
 320         FREE_AND_NULL(c->password);
 321         c->approved = 0;
 322 }
 323
 324 static int check_url_component(const char *url, int quiet,
 325                                const char *name, const char *value)
 326 {
 327         if (!value)
 328                 return 0;
 329         if (!strchr(value, '\n'))
 330                 return 0;
 331
 332         if (!quiet)
 333                 warning(_("url contains a newline in its %s component: %s"),
 334                         name, url);
 335         return -1;
 336 }
 337
 338 int credential_from_url_gently(struct credential *c, const char *url,
 339                                int quiet)
 340 {
 341         const char *at, *colon, *cp, *slash, *host, *proto_end;
 342
 343         credential_clear(c);
 344
 345         /*
 346          * Match one of:
 347          *   (1) proto://<host>/...
 348          *   (2) proto://<user>@<host>/...
 349          *   (3) proto://<user>:<pass>@<host>/...
 350          */
 351         proto_end = strstr(url, "://");
 352         if (!proto_end)
 353                 return 0;
 354         cp = proto_end + 3;
 355         at = strchr(cp, '@');
 356         colon = strchr(cp, ':');
 357         slash = strchrnul(cp, '/');
 358
 359         if (!at || slash <= at) {
 360                 /* Case (1) */
 361                 host = cp;
 362         }
 363         else if (!colon || at <= colon) {
 364                 /* Case (2) */
 365                 c->username = url_decode_mem(cp, at - cp);
 366                 host = at + 1;
 367         } else {
 368                 /* Case (3) */
 369                 c->username = url_decode_mem(cp, colon - cp);
 370                 c->password = url_decode_mem(colon + 1, at - (colon + 1));
 371                 host = at + 1;
 372         }
 373
 374         if (proto_end - url > 0)
 375                 c->protocol = xmemdupz(url, proto_end - url);
 376         c->host = url_decode_mem(host, slash - host);
 377         /* Trim leading and trailing slashes from path */
 378         while (*slash == '/')
 379                 slash++;
 380         if (*slash) {
 381                 char *p;
 382                 c->path = url_decode(slash);
 383                 p = c->path + strlen(c->path) - 1;
 384                 while (p > c->path && *p == '/')
 385                         *p-- = '\0';
 386         }
 387
 388         if (check_url_component(url, quiet, "username", c->username) < 0 ||
 389             check_url_component(url, quiet, "password", c->password) < 0 ||
 390             check_url_component(url, quiet, "protocol", c->protocol) < 0 ||
 391             check_url_component(url, quiet, "host", c->host) < 0 ||
 392             check_url_component(url, quiet, "path", c->path) < 0)
 393                 return -1;
 394
 395         return 0;
 396 }
 397
 398 void credential_from_url(struct credential *c, const char *url)
 399 {
 400         if (credential_from_url_gently(c, url, 0) < 0) {
 401                 warning(_("skipping credential lookup for url: %s"), url);
 402                 credential_clear(c);
 403         }
 404 }