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 #include "prompt.h"
   7
   8 void credential_init(struct credential *c)
   9 {
  10         memset(c, 0, sizeof(*c));
  11         c->helpers.strdup_strings = 1;
  12 }
  13
  14 void credential_clear(struct credential *c)
  15 {
  16         free(c->protocol);
  17         free(c->host);
  18         free(c->path);
  19         free(c->username);
  20         free(c->password);
  21         string_list_clear(&c->helpers, 0);
  22
  23         credential_init(c);
  24 }
  25
  26 int credential_match(const struct credential *want,
  27                      const struct credential *have)
  28 {
  29 #define CHECK(x) (!want->x || (have->x && !strcmp(want->x, have->x)))
  30         return CHECK(protocol) &&
  31                CHECK(host) &&
  32                CHECK(path) &&
  33                CHECK(username);
  34 #undef CHECK
  35 }
  36
  37 static int credential_config_callback(const char *var, const char *value,
  38                                       void *data)
  39 {
  40         struct credential *c = data;
  41         const char *key, *dot;
  42
  43         key = skip_prefix(var, "credential.");
  44         if (!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                 string_list_append(&c->helpers, value);
  69         else if (!strcmp(key, "username")) {
  70                 if (!c->username)
  71                         c->username = xstrdup(value);
  72         }
  73         else if (!strcmp(key, "usehttppath"))
  74                 c->use_http_path = git_config_bool(var, value);
  75
  76         return 0;
  77 }
  78
  79 static int proto_is_http(const char *s)
  80 {
  81         if (!s)
  82                 return 0;
  83         return !strcmp(s, "https") || !strcmp(s, "http");
  84 }
  85
  86 static void credential_apply_config(struct credential *c)
  87 {
  88         if (c->configured)
  89                 return;
  90         git_config(credential_config_callback, c);
  91         c->configured = 1;
  92
  93         if (!c->use_http_path && proto_is_http(c->protocol)) {
  94                 free(c->path);
  95                 c->path = NULL;
  96         }
  97 }
  98
  99 static void credential_describe(struct credential *c, struct strbuf *out)
 100 {
 101         if (!c->protocol)
 102                 return;
 103         strbuf_addf(out, "%s://", c->protocol);
 104         if (c->username && *c->username)
 105                 strbuf_addf(out, "%s@", c->username);
 106         if (c->host)
 107                 strbuf_addstr(out, c->host);
 108         if (c->path)
 109                 strbuf_addf(out, "/%s", c->path);
 110 }
 111
 112 static char *credential_ask_one(const char *what, struct credential *c)
 113 {
 114         struct strbuf desc = STRBUF_INIT;
 115         struct strbuf prompt = STRBUF_INIT;
 116         char *r;
 117
 118         credential_describe(c, &desc);
 119         if (desc.len)
 120                 strbuf_addf(&prompt, "%s for '%s': ", what, desc.buf);
 121         else
 122                 strbuf_addf(&prompt, "%s: ", what);
 123
 124         /* FIXME: for usernames, we should do something less magical that
 125          * actually echoes the characters. However, we need to read from
 126          * /dev/tty and not stdio, which is not portable (but getpass will do
 127          * it for us). http.c uses the same workaround. */
 128         r = git_getpass(prompt.buf);
 129
 130         strbuf_release(&desc);
 131         strbuf_release(&prompt);
 132         return xstrdup(r);
 133 }
 134
 135 static void credential_getpass(struct credential *c)
 136 {
 137         if (!c->username)
 138                 c->username = credential_ask_one("Username", c);
 139         if (!c->password)
 140                 c->password = credential_ask_one("Password", c);
 141 }
 142
 143 int credential_read(struct credential *c, FILE *fp)
 144 {
 145         struct strbuf line = STRBUF_INIT;
 146
 147         while (strbuf_getline(&line, fp, '\n') != EOF) {
 148                 char *key = line.buf;
 149                 char *value = strchr(key, '=');
 150
 151                 if (!line.len)
 152                         break;
 153
 154                 if (!value) {
 155                         warning("invalid credential line: %s", key);
 156                         strbuf_release(&line);
 157                         return -1;
 158                 }
 159                 *value++ = '\0';
 160
 161                 if (!strcmp(key, "username")) {
 162                         free(c->username);
 163                         c->username = xstrdup(value);
 164                 } else if (!strcmp(key, "password")) {
 165                         free(c->password);
 166                         c->password = xstrdup(value);
 167                 } else if (!strcmp(key, "protocol")) {
 168                         free(c->protocol);
 169                         c->protocol = xstrdup(value);
 170                 } else if (!strcmp(key, "host")) {
 171                         free(c->host);
 172                         c->host = xstrdup(value);
 173                 } else if (!strcmp(key, "path")) {
 174                         free(c->path);
 175                         c->path = xstrdup(value);
 176                 }
 177                 /*
 178                  * Ignore other lines; we don't know what they mean, but
 179                  * this future-proofs us when later versions of git do
 180                  * learn new lines, and the helpers are updated to match.
 181                  */
 182         }
 183
 184         strbuf_release(&line);
 185         return 0;
 186 }
 187
 188 static void credential_write_item(FILE *fp, const char *key, const char *value)
 189 {
 190         if (!value)
 191                 return;
 192         fprintf(fp, "%s=%s\n", key, value);
 193 }
 194
 195 static void credential_write(const struct credential *c, FILE *fp)
 196 {
 197         credential_write_item(fp, "protocol", c->protocol);
 198         credential_write_item(fp, "host", c->host);
 199         credential_write_item(fp, "path", c->path);
 200         credential_write_item(fp, "username", c->username);
 201         credential_write_item(fp, "password", c->password);
 202 }
 203
 204 static int run_credential_helper(struct credential *c,
 205                                  const char *cmd,
 206                                  int want_output)
 207 {
 208         struct child_process helper;
 209         const char *argv[] = { NULL, NULL };
 210         FILE *fp;
 211
 212         memset(&helper, 0, sizeof(helper));
 213         argv[0] = cmd;
 214         helper.argv = argv;
 215         helper.use_shell = 1;
 216         helper.in = -1;
 217         if (want_output)
 218                 helper.out = -1;
 219         else
 220                 helper.no_stdout = 1;
 221
 222         if (start_command(&helper) < 0)
 223                 return -1;
 224
 225         fp = xfdopen(helper.in, "w");
 226         credential_write(c, fp);
 227         fclose(fp);
 228
 229         if (want_output) {
 230                 int r;
 231                 fp = xfdopen(helper.out, "r");
 232                 r = credential_read(c, fp);
 233                 fclose(fp);
 234                 if (r < 0) {
 235                         finish_command(&helper);
 236                         return -1;
 237                 }
 238         }
 239
 240         if (finish_command(&helper))
 241                 return -1;
 242         return 0;
 243 }
 244
 245 static int credential_do(struct credential *c, const char *helper,
 246                          const char *operation)
 247 {
 248         struct strbuf cmd = STRBUF_INIT;
 249         int r;
 250
 251         if (helper[0] == '!')
 252                 strbuf_addstr(&cmd, helper + 1);
 253         else if (is_absolute_path(helper))
 254                 strbuf_addstr(&cmd, helper);
 255         else
 256                 strbuf_addf(&cmd, "git credential-%s", helper);
 257
 258         strbuf_addf(&cmd, " %s", operation);
 259         r = run_credential_helper(c, cmd.buf, !strcmp(operation, "get"));
 260
 261         strbuf_release(&cmd);
 262         return r;
 263 }
 264
 265 void credential_fill(struct credential *c)
 266 {
 267         int i;
 268
 269         if (c->username && c->password)
 270                 return;
 271
 272         credential_apply_config(c);
 273
 274         for (i = 0; i < c->helpers.nr; i++) {
 275                 credential_do(c, c->helpers.items[i].string, "get");
 276                 if (c->username && c->password)
 277                         return;
 278         }
 279
 280         credential_getpass(c);
 281         if (!c->username && !c->password)
 282                 die("unable to get password from user");
 283 }
 284
 285 void credential_approve(struct credential *c)
 286 {
 287         int i;
 288
 289         if (c->approved)
 290                 return;
 291         if (!c->username || !c->password)
 292                 return;
 293
 294         credential_apply_config(c);
 295
 296         for (i = 0; i < c->helpers.nr; i++)
 297                 credential_do(c, c->helpers.items[i].string, "store");
 298         c->approved = 1;
 299 }
 300
 301 void credential_reject(struct credential *c)
 302 {
 303         int i;
 304
 305         credential_apply_config(c);
 306
 307         for (i = 0; i < c->helpers.nr; i++)
 308                 credential_do(c, c->helpers.items[i].string, "erase");
 309
 310         free(c->username);
 311         c->username = NULL;
 312         free(c->password);
 313         c->password = NULL;
 314         c->approved = 0;
 315 }
 316
 317 void credential_from_url(struct credential *c, const char *url)
 318 {
 319         const char *at, *colon, *cp, *slash, *host, *proto_end;
 320
 321         credential_clear(c);
 322
 323         /*
 324          * Match one of:
 325          *   (1) proto://<host>/...
 326          *   (2) proto://<user>@<host>/...
 327          *   (3) proto://<user>:<pass>@<host>/...
 328          */
 329         proto_end = strstr(url, "://");
 330         if (!proto_end)
 331                 return;
 332         cp = proto_end + 3;
 333         at = strchr(cp, '@');
 334         colon = strchr(cp, ':');
 335         slash = strchrnul(cp, '/');
 336
 337         if (!at || slash <= at) {
 338                 /* Case (1) */
 339                 host = cp;
 340         }
 341         else if (!colon || at <= colon) {
 342                 /* Case (2) */
 343                 c->username = url_decode_mem(cp, at - cp);
 344                 host = at + 1;
 345         } else {
 346                 /* Case (3) */
 347                 c->username = url_decode_mem(cp, colon - cp);
 348                 c->password = url_decode_mem(colon + 1, at - (colon + 1));
 349                 host = at + 1;
 350         }
 351
 352         if (proto_end - url > 0)
 353                 c->protocol = xmemdupz(url, proto_end - url);
 354         if (slash - host > 0)
 355                 c->host = url_decode_mem(host, slash - host);
 356         /* Trim leading and trailing slashes from path */
 357         while (*slash == '/')
 358                 slash++;
 359         if (*slash) {
 360                 char *p;
 361                 c->path = url_decode(slash);
 362                 p = c->path + strlen(c->path) - 1;
 363                 while (p > c->path && *p == '/')
 364                         *p-- = '\0';
 365         }
 366 }