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         fprintf(fp, "%s=%s\n", key, value);
 198 }
 199
 200 void credential_write(const struct credential *c, FILE *fp)
 201 {
 202         credential_write_item(fp, "protocol", c->protocol);
 203         credential_write_item(fp, "host", c->host);
 204         credential_write_item(fp, "path", c->path);
 205         credential_write_item(fp, "username", c->username);
 206         credential_write_item(fp, "password", c->password);
 207 }
 208
 209 static int run_credential_helper(struct credential *c,
 210                                  const char *cmd,
 211                                  int want_output)
 212 {
 213         struct child_process helper = CHILD_PROCESS_INIT;
 214         const char *argv[] = { NULL, NULL };
 215         FILE *fp;
 216
 217         argv[0] = cmd;
 218         helper.argv = argv;
 219         helper.use_shell = 1;
 220         helper.in = -1;
 221         if (want_output)
 222                 helper.out = -1;
 223         else
 224                 helper.no_stdout = 1;
 225
 226         if (start_command(&helper) < 0)
 227                 return -1;
 228
 229         fp = xfdopen(helper.in, "w");
 230         credential_write(c, fp);
 231         fclose(fp);
 232
 233         if (want_output) {
 234                 int r;
 235                 fp = xfdopen(helper.out, "r");
 236                 r = credential_read(c, fp);
 237                 fclose(fp);
 238                 if (r < 0) {
 239                         finish_command(&helper);
 240                         return -1;
 241                 }
 242         }
 243
 244         if (finish_command(&helper))
 245                 return -1;
 246         return 0;
 247 }
 248
 249 static int credential_do(struct credential *c, const char *helper,
 250                          const char *operation)
 251 {
 252         struct strbuf cmd = STRBUF_INIT;
 253         int r;
 254
 255         if (helper[0] == '!')
 256                 strbuf_addstr(&cmd, helper + 1);
 257         else if (is_absolute_path(helper))
 258                 strbuf_addstr(&cmd, helper);
 259         else
 260                 strbuf_addf(&cmd, "git credential-%s", helper);
 261
 262         strbuf_addf(&cmd, " %s", operation);
 263         r = run_credential_helper(c, cmd.buf, !strcmp(operation, "get"));
 264
 265         strbuf_release(&cmd);
 266         return r;
 267 }
 268
 269 void credential_fill(struct credential *c)
 270 {
 271         int i;
 272
 273         if (c->username && c->password)
 274                 return;
 275
 276         credential_apply_config(c);
 277
 278         for (i = 0; i < c->helpers.nr; i++) {
 279                 credential_do(c, c->helpers.items[i].string, "get");
 280                 if (c->username && c->password)
 281                         return;
 282                 if (c->quit)
 283                         die("credential helper '%s' told us to quit",
 284                             c->helpers.items[i].string);
 285         }
 286
 287         credential_getpass(c);
 288         if (!c->username && !c->password)
 289                 die("unable to get password from user");
 290 }
 291
 292 void credential_approve(struct credential *c)
 293 {
 294         int i;
 295
 296         if (c->approved)
 297                 return;
 298         if (!c->username || !c->password)
 299                 return;
 300
 301         credential_apply_config(c);
 302
 303         for (i = 0; i < c->helpers.nr; i++)
 304                 credential_do(c, c->helpers.items[i].string, "store");
 305         c->approved = 1;
 306 }
 307
 308 void credential_reject(struct credential *c)
 309 {
 310         int i;
 311
 312         credential_apply_config(c);
 313
 314         for (i = 0; i < c->helpers.nr; i++)
 315                 credential_do(c, c->helpers.items[i].string, "erase");
 316
 317         FREE_AND_NULL(c->username);
 318         FREE_AND_NULL(c->password);
 319         c->approved = 0;
 320 }
 321
 322 void credential_from_url(struct credential *c, const char *url)
 323 {
 324         const char *at, *colon, *cp, *slash, *host, *proto_end;
 325
 326         credential_clear(c);
 327
 328         /*
 329          * Match one of:
 330          *   (1) proto://<host>/...
 331          *   (2) proto://<user>@<host>/...
 332          *   (3) proto://<user>:<pass>@<host>/...
 333          */
 334         proto_end = strstr(url, "://");
 335         if (!proto_end)
 336                 return;
 337         cp = proto_end + 3;
 338         at = strchr(cp, '@');
 339         colon = strchr(cp, ':');
 340         slash = strchrnul(cp, '/');
 341
 342         if (!at || slash <= at) {
 343                 /* Case (1) */
 344                 host = cp;
 345         }
 346         else if (!colon || at <= colon) {
 347                 /* Case (2) */
 348                 c->username = url_decode_mem(cp, at - cp);
 349                 host = at + 1;
 350         } else {
 351                 /* Case (3) */
 352                 c->username = url_decode_mem(cp, colon - cp);
 353                 c->password = url_decode_mem(colon + 1, at - (colon + 1));
 354                 host = at + 1;
 355         }
 356
 357         if (proto_end - url > 0)
 358                 c->protocol = xmemdupz(url, proto_end - url);
 359         if (slash - host > 0)
 360                 c->host = url_decode_mem(host, slash - host);
 361         /* Trim leading and trailing slashes from path */
 362         while (*slash == '/')
 363                 slash++;
 364         if (*slash) {
 365                 char *p;
 366                 c->path = url_decode(slash);
 367                 p = c->path + strlen(c->path) - 1;
 368                 while (p > c->path && *p == '/')
 369                         *p-- = '\0';
 370         }
 371 }