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
  69         return 0;
  70 }
  71
  72 static void credential_apply_config(struct credential *c)
  73 {
  74         if (c->configured)
  75                 return;
  76         git_config(credential_config_callback, c);
  77         c->configured = 1;
  78 }
  79
  80 static void credential_describe(struct credential *c, struct strbuf *out)
  81 {
  82         if (!c->protocol)
  83                 return;
  84         strbuf_addf(out, "%s://", c->protocol);
  85         if (c->username && *c->username)
  86                 strbuf_addf(out, "%s@", c->username);
  87         if (c->host)
  88                 strbuf_addstr(out, c->host);
  89         if (c->path)
  90                 strbuf_addf(out, "/%s", c->path);
  91 }
  92
  93 static char *credential_ask_one(const char *what, struct credential *c)
  94 {
  95         struct strbuf desc = STRBUF_INIT;
  96         struct strbuf prompt = STRBUF_INIT;
  97         char *r;
  98
  99         credential_describe(c, &desc);
 100         if (desc.len)
 101                 strbuf_addf(&prompt, "%s for '%s': ", what, desc.buf);
 102         else
 103                 strbuf_addf(&prompt, "%s: ", what);
 104
 105         /* FIXME: for usernames, we should do something less magical that
 106          * actually echoes the characters. However, we need to read from
 107          * /dev/tty and not stdio, which is not portable (but getpass will do
 108          * it for us). http.c uses the same workaround. */
 109         r = git_getpass(prompt.buf);
 110
 111         strbuf_release(&desc);
 112         strbuf_release(&prompt);
 113         return xstrdup(r);
 114 }
 115
 116 static void credential_getpass(struct credential *c)
 117 {
 118         if (!c->username)
 119                 c->username = credential_ask_one("Username", c);
 120         if (!c->password)
 121                 c->password = credential_ask_one("Password", c);
 122 }
 123
 124 int credential_read(struct credential *c, FILE *fp)
 125 {
 126         struct strbuf line = STRBUF_INIT;
 127
 128         while (strbuf_getline(&line, fp, '\n') != EOF) {
 129                 char *key = line.buf;
 130                 char *value = strchr(key, '=');
 131
 132                 if (!line.len)
 133                         break;
 134
 135                 if (!value) {
 136                         warning("invalid credential line: %s", key);
 137                         strbuf_release(&line);
 138                         return -1;
 139                 }
 140                 *value++ = '\0';
 141
 142                 if (!strcmp(key, "username")) {
 143                         free(c->username);
 144                         c->username = xstrdup(value);
 145                 } else if (!strcmp(key, "password")) {
 146                         free(c->password);
 147                         c->password = xstrdup(value);
 148                 } else if (!strcmp(key, "protocol")) {
 149                         free(c->protocol);
 150                         c->protocol = xstrdup(value);
 151                 } else if (!strcmp(key, "host")) {
 152                         free(c->host);
 153                         c->host = xstrdup(value);
 154                 } else if (!strcmp(key, "path")) {
 155                         free(c->path);
 156                         c->path = xstrdup(value);
 157                 }
 158                 /*
 159                  * Ignore other lines; we don't know what they mean, but
 160                  * this future-proofs us when later versions of git do
 161                  * learn new lines, and the helpers are updated to match.
 162                  */
 163         }
 164
 165         strbuf_release(&line);
 166         return 0;
 167 }
 168
 169 static void credential_write_item(FILE *fp, const char *key, const char *value)
 170 {
 171         if (!value)
 172                 return;
 173         fprintf(fp, "%s=%s\n", key, value);
 174 }
 175
 176 static void credential_write(const struct credential *c, FILE *fp)
 177 {
 178         credential_write_item(fp, "protocol", c->protocol);
 179         credential_write_item(fp, "host", c->host);
 180         credential_write_item(fp, "path", c->path);
 181         credential_write_item(fp, "username", c->username);
 182         credential_write_item(fp, "password", c->password);
 183 }
 184
 185 static int run_credential_helper(struct credential *c,
 186                                  const char *cmd,
 187                                  int want_output)
 188 {
 189         struct child_process helper;
 190         const char *argv[] = { NULL, NULL };
 191         FILE *fp;
 192
 193         memset(&helper, 0, sizeof(helper));
 194         argv[0] = cmd;
 195         helper.argv = argv;
 196         helper.use_shell = 1;
 197         helper.in = -1;
 198         if (want_output)
 199                 helper.out = -1;
 200         else
 201                 helper.no_stdout = 1;
 202
 203         if (start_command(&helper) < 0)
 204                 return -1;
 205
 206         fp = xfdopen(helper.in, "w");
 207         credential_write(c, fp);
 208         fclose(fp);
 209
 210         if (want_output) {
 211                 int r;
 212                 fp = xfdopen(helper.out, "r");
 213                 r = credential_read(c, fp);
 214                 fclose(fp);
 215                 if (r < 0) {
 216                         finish_command(&helper);
 217                         return -1;
 218                 }
 219         }
 220
 221         if (finish_command(&helper))
 222                 return -1;
 223         return 0;
 224 }
 225
 226 static int credential_do(struct credential *c, const char *helper,
 227                          const char *operation)
 228 {
 229         struct strbuf cmd = STRBUF_INIT;
 230         int r;
 231
 232         if (helper[0] == '!')
 233                 strbuf_addstr(&cmd, helper + 1);
 234         else if (is_absolute_path(helper))
 235                 strbuf_addstr(&cmd, helper);
 236         else
 237                 strbuf_addf(&cmd, "git credential-%s", helper);
 238
 239         strbuf_addf(&cmd, " %s", operation);
 240         r = run_credential_helper(c, cmd.buf, !strcmp(operation, "get"));
 241
 242         strbuf_release(&cmd);
 243         return r;
 244 }
 245
 246 void credential_fill(struct credential *c)
 247 {
 248         int i;
 249
 250         if (c->username && c->password)
 251                 return;
 252
 253         credential_apply_config(c);
 254
 255         for (i = 0; i < c->helpers.nr; i++) {
 256                 credential_do(c, c->helpers.items[i].string, "get");
 257                 if (c->username && c->password)
 258                         return;
 259         }
 260
 261         credential_getpass(c);
 262         if (!c->username && !c->password)
 263                 die("unable to get password from user");
 264 }
 265
 266 void credential_approve(struct credential *c)
 267 {
 268         int i;
 269
 270         if (c->approved)
 271                 return;
 272         if (!c->username || !c->password)
 273                 return;
 274
 275         credential_apply_config(c);
 276
 277         for (i = 0; i < c->helpers.nr; i++)
 278                 credential_do(c, c->helpers.items[i].string, "store");
 279         c->approved = 1;
 280 }
 281
 282 void credential_reject(struct credential *c)
 283 {
 284         int i;
 285
 286         credential_apply_config(c);
 287
 288         for (i = 0; i < c->helpers.nr; i++)
 289                 credential_do(c, c->helpers.items[i].string, "erase");
 290
 291         free(c->username);
 292         c->username = NULL;
 293         free(c->password);
 294         c->password = NULL;
 295         c->approved = 0;
 296 }
 297
 298 void credential_from_url(struct credential *c, const char *url)
 299 {
 300         const char *at, *colon, *cp, *slash, *host, *proto_end;
 301
 302         credential_clear(c);
 303
 304         /*
 305          * Match one of:
 306          *   (1) proto://<host>/...
 307          *   (2) proto://<user>@<host>/...
 308          *   (3) proto://<user>:<pass>@<host>/...
 309          */
 310         proto_end = strstr(url, "://");
 311         if (!proto_end)
 312                 return;
 313         cp = proto_end + 3;
 314         at = strchr(cp, '@');
 315         colon = strchr(cp, ':');
 316         slash = strchrnul(cp, '/');
 317
 318         if (!at || slash <= at) {
 319                 /* Case (1) */
 320                 host = cp;
 321         }
 322         else if (!colon || at <= colon) {
 323                 /* Case (2) */
 324                 c->username = url_decode_mem(cp, at - cp);
 325                 host = at + 1;
 326         } else {
 327                 /* Case (3) */
 328                 c->username = url_decode_mem(cp, colon - cp);
 329                 c->password = url_decode_mem(colon + 1, at - (colon + 1));
 330                 host = at + 1;
 331         }
 332
 333         if (proto_end - url > 0)
 334                 c->protocol = xmemdupz(url, proto_end - url);
 335         if (slash - host > 0)
 336                 c->host = url_decode_mem(host, slash - host);
 337         /* Trim leading and trailing slashes from path */
 338         while (*slash == '/')
 339                 slash++;
 340         if (*slash) {
 341                 char *p;
 342                 c->path = url_decode(slash);
 343                 p = c->path + strlen(c->path) - 1;
 344                 while (p > c->path && *p == '/')
 345                         *p-- = '\0';
 346         }
 347 }