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
  73         return 0;
  74 }
  75
  76 static void credential_apply_config(struct credential *c)
  77 {
  78         if (c->configured)
  79                 return;
  80         git_config(credential_config_callback, c);
  81         c->configured = 1;
  82 }
  83
  84 static void credential_describe(struct credential *c, struct strbuf *out)
  85 {
  86         if (!c->protocol)
  87                 return;
  88         strbuf_addf(out, "%s://", c->protocol);
  89         if (c->username && *c->username)
  90                 strbuf_addf(out, "%s@", c->username);
  91         if (c->host)
  92                 strbuf_addstr(out, c->host);
  93         if (c->path)
  94                 strbuf_addf(out, "/%s", c->path);
  95 }
  96
  97 static char *credential_ask_one(const char *what, struct credential *c)
  98 {
  99         struct strbuf desc = STRBUF_INIT;
 100         struct strbuf prompt = STRBUF_INIT;
 101         char *r;
 102
 103         credential_describe(c, &desc);
 104         if (desc.len)
 105                 strbuf_addf(&prompt, "%s for '%s': ", what, desc.buf);
 106         else
 107                 strbuf_addf(&prompt, "%s: ", what);
 108
 109         /* FIXME: for usernames, we should do something less magical that
 110          * actually echoes the characters. However, we need to read from
 111          * /dev/tty and not stdio, which is not portable (but getpass will do
 112          * it for us). http.c uses the same workaround. */
 113         r = git_getpass(prompt.buf);
 114
 115         strbuf_release(&desc);
 116         strbuf_release(&prompt);
 117         return xstrdup(r);
 118 }
 119
 120 static void credential_getpass(struct credential *c)
 121 {
 122         if (!c->username)
 123                 c->username = credential_ask_one("Username", c);
 124         if (!c->password)
 125                 c->password = credential_ask_one("Password", c);
 126 }
 127
 128 int credential_read(struct credential *c, FILE *fp)
 129 {
 130         struct strbuf line = STRBUF_INIT;
 131
 132         while (strbuf_getline(&line, fp, '\n') != EOF) {
 133                 char *key = line.buf;
 134                 char *value = strchr(key, '=');
 135
 136                 if (!line.len)
 137                         break;
 138
 139                 if (!value) {
 140                         warning("invalid credential line: %s", key);
 141                         strbuf_release(&line);
 142                         return -1;
 143                 }
 144                 *value++ = '\0';
 145
 146                 if (!strcmp(key, "username")) {
 147                         free(c->username);
 148                         c->username = xstrdup(value);
 149                 } else if (!strcmp(key, "password")) {
 150                         free(c->password);
 151                         c->password = xstrdup(value);
 152                 } else if (!strcmp(key, "protocol")) {
 153                         free(c->protocol);
 154                         c->protocol = xstrdup(value);
 155                 } else if (!strcmp(key, "host")) {
 156                         free(c->host);
 157                         c->host = xstrdup(value);
 158                 } else if (!strcmp(key, "path")) {
 159                         free(c->path);
 160                         c->path = xstrdup(value);
 161                 }
 162                 /*
 163                  * Ignore other lines; we don't know what they mean, but
 164                  * this future-proofs us when later versions of git do
 165                  * learn new lines, and the helpers are updated to match.
 166                  */
 167         }
 168
 169         strbuf_release(&line);
 170         return 0;
 171 }
 172
 173 static void credential_write_item(FILE *fp, const char *key, const char *value)
 174 {
 175         if (!value)
 176                 return;
 177         fprintf(fp, "%s=%s\n", key, value);
 178 }
 179
 180 static void credential_write(const struct credential *c, FILE *fp)
 181 {
 182         credential_write_item(fp, "protocol", c->protocol);
 183         credential_write_item(fp, "host", c->host);
 184         credential_write_item(fp, "path", c->path);
 185         credential_write_item(fp, "username", c->username);
 186         credential_write_item(fp, "password", c->password);
 187 }
 188
 189 static int run_credential_helper(struct credential *c,
 190                                  const char *cmd,
 191                                  int want_output)
 192 {
 193         struct child_process helper;
 194         const char *argv[] = { NULL, NULL };
 195         FILE *fp;
 196
 197         memset(&helper, 0, sizeof(helper));
 198         argv[0] = cmd;
 199         helper.argv = argv;
 200         helper.use_shell = 1;
 201         helper.in = -1;
 202         if (want_output)
 203                 helper.out = -1;
 204         else
 205                 helper.no_stdout = 1;
 206
 207         if (start_command(&helper) < 0)
 208                 return -1;
 209
 210         fp = xfdopen(helper.in, "w");
 211         credential_write(c, fp);
 212         fclose(fp);
 213
 214         if (want_output) {
 215                 int r;
 216                 fp = xfdopen(helper.out, "r");
 217                 r = credential_read(c, fp);
 218                 fclose(fp);
 219                 if (r < 0) {
 220                         finish_command(&helper);
 221                         return -1;
 222                 }
 223         }
 224
 225         if (finish_command(&helper))
 226                 return -1;
 227         return 0;
 228 }
 229
 230 static int credential_do(struct credential *c, const char *helper,
 231                          const char *operation)
 232 {
 233         struct strbuf cmd = STRBUF_INIT;
 234         int r;
 235
 236         if (helper[0] == '!')
 237                 strbuf_addstr(&cmd, helper + 1);
 238         else if (is_absolute_path(helper))
 239                 strbuf_addstr(&cmd, helper);
 240         else
 241                 strbuf_addf(&cmd, "git credential-%s", helper);
 242
 243         strbuf_addf(&cmd, " %s", operation);
 244         r = run_credential_helper(c, cmd.buf, !strcmp(operation, "get"));
 245
 246         strbuf_release(&cmd);
 247         return r;
 248 }
 249
 250 void credential_fill(struct credential *c)
 251 {
 252         int i;
 253
 254         if (c->username && c->password)
 255                 return;
 256
 257         credential_apply_config(c);
 258
 259         for (i = 0; i < c->helpers.nr; i++) {
 260                 credential_do(c, c->helpers.items[i].string, "get");
 261                 if (c->username && c->password)
 262                         return;
 263         }
 264
 265         credential_getpass(c);
 266         if (!c->username && !c->password)
 267                 die("unable to get password from user");
 268 }
 269
 270 void credential_approve(struct credential *c)
 271 {
 272         int i;
 273
 274         if (c->approved)
 275                 return;
 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, "store");
 283         c->approved = 1;
 284 }
 285
 286 void credential_reject(struct credential *c)
 287 {
 288         int i;
 289
 290         credential_apply_config(c);
 291
 292         for (i = 0; i < c->helpers.nr; i++)
 293                 credential_do(c, c->helpers.items[i].string, "erase");
 294
 295         free(c->username);
 296         c->username = NULL;
 297         free(c->password);
 298         c->password = NULL;
 299         c->approved = 0;
 300 }
 301
 302 void credential_from_url(struct credential *c, const char *url)
 303 {
 304         const char *at, *colon, *cp, *slash, *host, *proto_end;
 305
 306         credential_clear(c);
 307
 308         /*
 309          * Match one of:
 310          *   (1) proto://<host>/...
 311          *   (2) proto://<user>@<host>/...
 312          *   (3) proto://<user>:<pass>@<host>/...
 313          */
 314         proto_end = strstr(url, "://");
 315         if (!proto_end)
 316                 return;
 317         cp = proto_end + 3;
 318         at = strchr(cp, '@');
 319         colon = strchr(cp, ':');
 320         slash = strchrnul(cp, '/');
 321
 322         if (!at || slash <= at) {
 323                 /* Case (1) */
 324                 host = cp;
 325         }
 326         else if (!colon || at <= colon) {
 327                 /* Case (2) */
 328                 c->username = url_decode_mem(cp, at - cp);
 329                 host = at + 1;
 330         } else {
 331                 /* Case (3) */
 332                 c->username = url_decode_mem(cp, colon - cp);
 333                 c->password = url_decode_mem(colon + 1, at - (colon + 1));
 334                 host = at + 1;
 335         }
 336
 337         if (proto_end - url > 0)
 338                 c->protocol = xmemdupz(url, proto_end - url);
 339         if (slash - host > 0)
 340                 c->host = url_decode_mem(host, slash - host);
 341         /* Trim leading and trailing slashes from path */
 342         while (*slash == '/')
 343                 slash++;
 344         if (*slash) {
 345                 char *p;
 346                 c->path = url_decode(slash);
 347                 p = c->path + strlen(c->path) - 1;
 348                 while (p > c->path && *p == '/')
 349                         *p-- = '\0';
 350         }
 351 }