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         if (!skip_prefix(var, "credential.", &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                                 int flags)
 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         r = git_prompt(prompt.buf, flags);
 125
 126         strbuf_release(&desc);
 127         strbuf_release(&prompt);
 128         return xstrdup(r);
 129 }
 130
 131 static void credential_getpass(struct credential *c)
 132 {
 133         if (!c->username)
 134                 c->username = credential_ask_one("Username", c,
 135                                                  PROMPT_ASKPASS|PROMPT_ECHO);
 136         if (!c->password)
 137                 c->password = credential_ask_one("Password", c,
 138                                                  PROMPT_ASKPASS);
 139 }
 140
 141 int credential_read(struct credential *c, FILE *fp)
 142 {
 143         struct strbuf line = STRBUF_INIT;
 144
 145         while (strbuf_getline(&line, fp, '\n') != EOF) {
 146                 char *key = line.buf;
 147                 char *value = strchr(key, '=');
 148
 149                 if (!line.len)
 150                         break;
 151
 152                 if (!value) {
 153                         warning("invalid credential line: %s", key);
 154                         strbuf_release(&line);
 155                         return -1;
 156                 }
 157                 *value++ = '\0';
 158
 159                 if (!strcmp(key, "username")) {
 160                         free(c->username);
 161                         c->username = xstrdup(value);
 162                 } else if (!strcmp(key, "password")) {
 163                         free(c->password);
 164                         c->password = xstrdup(value);
 165                 } else if (!strcmp(key, "protocol")) {
 166                         free(c->protocol);
 167                         c->protocol = xstrdup(value);
 168                 } else if (!strcmp(key, "host")) {
 169                         free(c->host);
 170                         c->host = xstrdup(value);
 171                 } else if (!strcmp(key, "path")) {
 172                         free(c->path);
 173                         c->path = xstrdup(value);
 174                 } else if (!strcmp(key, "url")) {
 175                         credential_from_url(c, value);
 176                 } else if (!strcmp(key, "quit")) {
 177                         c->quit = !!git_config_bool("quit", value);
 178                 }
 179                 /*
 180                  * Ignore other lines; we don't know what they mean, but
 181                  * this future-proofs us when later versions of git do
 182                  * learn new lines, and the helpers are updated to match.
 183                  */
 184         }
 185
 186         strbuf_release(&line);
 187         return 0;
 188 }
 189
 190 static void credential_write_item(FILE *fp, const char *key, const char *value)
 191 {
 192         if (!value)
 193                 return;
 194         fprintf(fp, "%s=%s\n", key, value);
 195 }
 196
 197 void credential_write(const struct credential *c, FILE *fp)
 198 {
 199         credential_write_item(fp, "protocol", c->protocol);
 200         credential_write_item(fp, "host", c->host);
 201         credential_write_item(fp, "path", c->path);
 202         credential_write_item(fp, "username", c->username);
 203         credential_write_item(fp, "password", c->password);
 204 }
 205
 206 static int run_credential_helper(struct credential *c,
 207                                  const char *cmd,
 208                                  int want_output)
 209 {
 210         struct child_process helper = CHILD_PROCESS_INIT;
 211         const char *argv[] = { NULL, NULL };
 212         FILE *fp;
 213
 214         argv[0] = cmd;
 215         helper.argv = argv;
 216         helper.use_shell = 1;
 217         helper.in = -1;
 218         if (want_output)
 219                 helper.out = -1;
 220         else
 221                 helper.no_stdout = 1;
 222
 223         if (start_command(&helper) < 0)
 224                 return -1;
 225
 226         fp = xfdopen(helper.in, "w");
 227         credential_write(c, fp);
 228         fclose(fp);
 229
 230         if (want_output) {
 231                 int r;
 232                 fp = xfdopen(helper.out, "r");
 233                 r = credential_read(c, fp);
 234                 fclose(fp);
 235                 if (r < 0) {
 236                         finish_command(&helper);
 237                         return -1;
 238                 }
 239         }
 240
 241         if (finish_command(&helper))
 242                 return -1;
 243         return 0;
 244 }
 245
 246 static int credential_do(struct credential *c, const char *helper,
 247                          const char *operation)
 248 {
 249         struct strbuf cmd = STRBUF_INIT;
 250         int r;
 251
 252         if (helper[0] == '!')
 253                 strbuf_addstr(&cmd, helper + 1);
 254         else if (is_absolute_path(helper))
 255                 strbuf_addstr(&cmd, helper);
 256         else
 257                 strbuf_addf(&cmd, "git credential-%s", helper);
 258
 259         strbuf_addf(&cmd, " %s", operation);
 260         r = run_credential_helper(c, cmd.buf, !strcmp(operation, "get"));
 261
 262         strbuf_release(&cmd);
 263         return r;
 264 }
 265
 266 void credential_fill(struct credential *c)
 267 {
 268         int i;
 269
 270         if (c->username && c->password)
 271                 return;
 272
 273         credential_apply_config(c);
 274
 275         for (i = 0; i < c->helpers.nr; i++) {
 276                 credential_do(c, c->helpers.items[i].string, "get");
 277                 if (c->username && c->password)
 278                         return;
 279                 if (c->quit)
 280                         die("credential helper '%s' told us to quit",
 281                             c->helpers.items[i].string);
 282         }
 283
 284         credential_getpass(c);
 285         if (!c->username && !c->password)
 286                 die("unable to get password from user");
 287 }
 288
 289 void credential_approve(struct credential *c)
 290 {
 291         int i;
 292
 293         if (c->approved)
 294                 return;
 295         if (!c->username || !c->password)
 296                 return;
 297
 298         credential_apply_config(c);
 299
 300         for (i = 0; i < c->helpers.nr; i++)
 301                 credential_do(c, c->helpers.items[i].string, "store");
 302         c->approved = 1;
 303 }
 304
 305 void credential_reject(struct credential *c)
 306 {
 307         int i;
 308
 309         credential_apply_config(c);
 310
 311         for (i = 0; i < c->helpers.nr; i++)
 312                 credential_do(c, c->helpers.items[i].string, "erase");
 313
 314         free(c->username);
 315         c->username = NULL;
 316         free(c->password);
 317         c->password = NULL;
 318         c->approved = 0;
 319 }
 320
 321 void credential_from_url(struct credential *c, const char *url)
 322 {
 323         const char *at, *colon, *cp, *slash, *host, *proto_end;
 324
 325         credential_clear(c);
 326
 327         /*
 328          * Match one of:
 329          *   (1) proto://<host>/...
 330          *   (2) proto://<user>@<host>/...
 331          *   (3) proto://<user>:<pass>@<host>/...
 332          */
 333         proto_end = strstr(url, "://");
 334         if (!proto_end)
 335                 return;
 336         cp = proto_end + 3;
 337         at = strchr(cp, '@');
 338         colon = strchr(cp, ':');
 339         slash = strchrnul(cp, '/');
 340
 341         if (!at || slash <= at) {
 342                 /* Case (1) */
 343                 host = cp;
 344         }
 345         else if (!colon || at <= colon) {
 346                 /* Case (2) */
 347                 c->username = url_decode_mem(cp, at - cp);
 348                 host = at + 1;
 349         } else {
 350                 /* Case (3) */
 351                 c->username = url_decode_mem(cp, colon - cp);
 352                 c->password = url_decode_mem(colon + 1, at - (colon + 1));
 353                 host = at + 1;
 354         }
 355
 356         if (proto_end - url > 0)
 357                 c->protocol = xmemdupz(url, proto_end - url);
 358         if (slash - host > 0)
 359                 c->host = url_decode_mem(host, slash - host);
 360         /* Trim leading and trailing slashes from path */
 361         while (*slash == '/')
 362                 slash++;
 363         if (*slash) {
 364                 char *p;
 365                 c->path = url_decode(slash);
 366                 p = c->path + strlen(c->path) - 1;
 367                 while (p > c->path && *p == '/')
 368                         *p-- = '\0';
 369         }
 370 }