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
   7 void credential_init(struct credential *c)
   8 {
   9         memset(c, 0, sizeof(*c));
  10         c->helpers.strdup_strings = 1;
  11 }
  12
  13 void credential_clear(struct credential *c)
  14 {
  15         free(c->protocol);
  16         free(c->host);
  17         free(c->path);
  18         free(c->username);
  19         free(c->password);
  20         string_list_clear(&c->helpers, 0);
  21
  22         credential_init(c);
  23 }
  24
  25 int credential_match(const struct credential *want,
  26                      const struct credential *have)
  27 {
  28 #define CHECK(x) (!want->x || (have->x && !strcmp(want->x, have->x)))
  29         return CHECK(protocol) &&
  30                CHECK(host) &&
  31                CHECK(path) &&
  32                CHECK(username);
  33 #undef CHECK
  34 }
  35
  36 static int credential_config_callback(const char *var, const char *value,
  37                                       void *data)
  38 {
  39         struct credential *c = data;
  40         const char *key, *dot;
  41
  42         key = skip_prefix(var, "credential.");
  43         if (!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 {
 113         struct strbuf desc = STRBUF_INIT;
 114         struct strbuf prompt = STRBUF_INIT;
 115         char *r;
 116
 117         credential_describe(c, &desc);
 118         if (desc.len)
 119                 strbuf_addf(&prompt, "%s for '%s': ", what, desc.buf);
 120         else
 121                 strbuf_addf(&prompt, "%s: ", what);
 122
 123         /* FIXME: for usernames, we should do something less magical that
 124          * actually echoes the characters. However, we need to read from
 125          * /dev/tty and not stdio, which is not portable (but getpass will do
 126          * it for us). http.c uses the same workaround. */
 127         r = git_getpass(prompt.buf);
 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         if (!c->password)
 139                 c->password = credential_ask_one("Password", c);
 140 }
 141
 142 int credential_read(struct credential *c, FILE *fp)
 143 {
 144         struct strbuf line = STRBUF_INIT;
 145
 146         while (strbuf_getline(&line, fp, '\n') != EOF) {
 147                 char *key = line.buf;
 148                 char *value = strchr(key, '=');
 149
 150                 if (!line.len)
 151                         break;
 152
 153                 if (!value) {
 154                         warning("invalid credential line: %s", key);
 155                         strbuf_release(&line);
 156                         return -1;
 157                 }
 158                 *value++ = '\0';
 159
 160                 if (!strcmp(key, "username")) {
 161                         free(c->username);
 162                         c->username = xstrdup(value);
 163                 } else if (!strcmp(key, "password")) {
 164                         free(c->password);
 165                         c->password = xstrdup(value);
 166                 } else if (!strcmp(key, "protocol")) {
 167                         free(c->protocol);
 168                         c->protocol = xstrdup(value);
 169                 } else if (!strcmp(key, "host")) {
 170                         free(c->host);
 171                         c->host = xstrdup(value);
 172                 } else if (!strcmp(key, "path")) {
 173                         free(c->path);
 174                         c->path = xstrdup(value);
 175                 }
 176                 /*
 177                  * Ignore other lines; we don't know what they mean, but
 178                  * this future-proofs us when later versions of git do
 179                  * learn new lines, and the helpers are updated to match.
 180                  */
 181         }
 182
 183         strbuf_release(&line);
 184         return 0;
 185 }
 186
 187 static void credential_write_item(FILE *fp, const char *key, const char *value)
 188 {
 189         if (!value)
 190                 return;
 191         fprintf(fp, "%s=%s\n", key, value);
 192 }
 193
 194 static void credential_write(const struct credential *c, FILE *fp)
 195 {
 196         credential_write_item(fp, "protocol", c->protocol);
 197         credential_write_item(fp, "host", c->host);
 198         credential_write_item(fp, "path", c->path);
 199         credential_write_item(fp, "username", c->username);
 200         credential_write_item(fp, "password", c->password);
 201 }
 202
 203 static int run_credential_helper(struct credential *c,
 204                                  const char *cmd,
 205                                  int want_output)
 206 {
 207         struct child_process helper;
 208         const char *argv[] = { NULL, NULL };
 209         FILE *fp;
 210
 211         memset(&helper, 0, sizeof(helper));
 212         argv[0] = cmd;
 213         helper.argv = argv;
 214         helper.use_shell = 1;
 215         helper.in = -1;
 216         if (want_output)
 217                 helper.out = -1;
 218         else
 219                 helper.no_stdout = 1;
 220
 221         if (start_command(&helper) < 0)
 222                 return -1;
 223
 224         fp = xfdopen(helper.in, "w");
 225         credential_write(c, fp);
 226         fclose(fp);
 227
 228         if (want_output) {
 229                 int r;
 230                 fp = xfdopen(helper.out, "r");
 231                 r = credential_read(c, fp);
 232                 fclose(fp);
 233                 if (r < 0) {
 234                         finish_command(&helper);
 235                         return -1;
 236                 }
 237         }
 238
 239         if (finish_command(&helper))
 240                 return -1;
 241         return 0;
 242 }
 243
 244 static int credential_do(struct credential *c, const char *helper,
 245                          const char *operation)
 246 {
 247         struct strbuf cmd = STRBUF_INIT;
 248         int r;
 249
 250         if (helper[0] == '!')
 251                 strbuf_addstr(&cmd, helper + 1);
 252         else if (is_absolute_path(helper))
 253                 strbuf_addstr(&cmd, helper);
 254         else
 255                 strbuf_addf(&cmd, "git credential-%s", helper);
 256
 257         strbuf_addf(&cmd, " %s", operation);
 258         r = run_credential_helper(c, cmd.buf, !strcmp(operation, "get"));
 259
 260         strbuf_release(&cmd);
 261         return r;
 262 }
 263
 264 void credential_fill(struct credential *c)
 265 {
 266         int i;
 267
 268         if (c->username && c->password)
 269                 return;
 270
 271         credential_apply_config(c);
 272
 273         for (i = 0; i < c->helpers.nr; i++) {
 274                 credential_do(c, c->helpers.items[i].string, "get");
 275                 if (c->username && c->password)
 276                         return;
 277         }
 278
 279         credential_getpass(c);
 280         if (!c->username && !c->password)
 281                 die("unable to get password from user");
 282 }
 283
 284 void credential_approve(struct credential *c)
 285 {
 286         int i;
 287
 288         if (c->approved)
 289                 return;
 290         if (!c->username || !c->password)
 291                 return;
 292
 293         credential_apply_config(c);
 294
 295         for (i = 0; i < c->helpers.nr; i++)
 296                 credential_do(c, c->helpers.items[i].string, "store");
 297         c->approved = 1;
 298 }
 299
 300 void credential_reject(struct credential *c)
 301 {
 302         int i;
 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, "erase");
 308
 309         free(c->username);
 310         c->username = NULL;
 311         free(c->password);
 312         c->password = NULL;
 313         c->approved = 0;
 314 }
 315
 316 void credential_from_url(struct credential *c, const char *url)
 317 {
 318         const char *at, *colon, *cp, *slash, *host, *proto_end;
 319
 320         credential_clear(c);
 321
 322         /*
 323          * Match one of:
 324          *   (1) proto://<host>/...
 325          *   (2) proto://<user>@<host>/...
 326          *   (3) proto://<user>:<pass>@<host>/...
 327          */
 328         proto_end = strstr(url, "://");
 329         if (!proto_end)
 330                 return;
 331         cp = proto_end + 3;
 332         at = strchr(cp, '@');
 333         colon = strchr(cp, ':');
 334         slash = strchrnul(cp, '/');
 335
 336         if (!at || slash <= at) {
 337                 /* Case (1) */
 338                 host = cp;
 339         }
 340         else if (!colon || at <= colon) {
 341                 /* Case (2) */
 342                 c->username = url_decode_mem(cp, at - cp);
 343                 host = at + 1;
 344         } else {
 345                 /* Case (3) */
 346                 c->username = url_decode_mem(cp, colon - cp);
 347                 c->password = url_decode_mem(colon + 1, at - (colon + 1));
 348                 host = at + 1;
 349         }
 350
 351         if (proto_end - url > 0)
 352                 c->protocol = xmemdupz(url, proto_end - url);
 353         if (slash - host > 0)
 354                 c->host = url_decode_mem(host, slash - host);
 355         /* Trim leading and trailing slashes from path */
 356         while (*slash == '/')
 357                 slash++;
 358         if (*slash) {
 359                 char *p;
 360                 c->path = url_decode(slash);
 361                 p = c->path + strlen(c->path) - 1;
 362                 while (p > c->path && *p == '/')
 363                         *p-- = '\0';
 364         }
 365 }