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                 }
 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 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 }