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 static void credential_describe(struct credential *c, struct strbuf *out)
  26 {
  27         if (!c->protocol)
  28                 return;
  29         strbuf_addf(out, "%s://", c->protocol);
  30         if (c->username && *c->username)
  31                 strbuf_addf(out, "%s@", c->username);
  32         if (c->host)
  33                 strbuf_addstr(out, c->host);
  34         if (c->path)
  35                 strbuf_addf(out, "/%s", c->path);
  36 }
  37
  38 static char *credential_ask_one(const char *what, struct credential *c)
  39 {
  40         struct strbuf desc = STRBUF_INIT;
  41         struct strbuf prompt = STRBUF_INIT;
  42         char *r;
  43
  44         credential_describe(c, &desc);
  45         if (desc.len)
  46                 strbuf_addf(&prompt, "%s for '%s': ", what, desc.buf);
  47         else
  48                 strbuf_addf(&prompt, "%s: ", what);
  49
  50         /* FIXME: for usernames, we should do something less magical that
  51          * actually echoes the characters. However, we need to read from
  52          * /dev/tty and not stdio, which is not portable (but getpass will do
  53          * it for us). http.c uses the same workaround. */
  54         r = git_getpass(prompt.buf);
  55
  56         strbuf_release(&desc);
  57         strbuf_release(&prompt);
  58         return xstrdup(r);
  59 }
  60
  61 static void credential_getpass(struct credential *c)
  62 {
  63         if (!c->username)
  64                 c->username = credential_ask_one("Username", c);
  65         if (!c->password)
  66                 c->password = credential_ask_one("Password", c);
  67 }
  68
  69 int credential_read(struct credential *c, FILE *fp)
  70 {
  71         struct strbuf line = STRBUF_INIT;
  72
  73         while (strbuf_getline(&line, fp, '\n') != EOF) {
  74                 char *key = line.buf;
  75                 char *value = strchr(key, '=');
  76
  77                 if (!line.len)
  78                         break;
  79
  80                 if (!value) {
  81                         warning("invalid credential line: %s", key);
  82                         strbuf_release(&line);
  83                         return -1;
  84                 }
  85                 *value++ = '\0';
  86
  87                 if (!strcmp(key, "username")) {
  88                         free(c->username);
  89                         c->username = xstrdup(value);
  90                 } else if (!strcmp(key, "password")) {
  91                         free(c->password);
  92                         c->password = xstrdup(value);
  93                 } else if (!strcmp(key, "protocol")) {
  94                         free(c->protocol);
  95                         c->protocol = xstrdup(value);
  96                 } else if (!strcmp(key, "host")) {
  97                         free(c->host);
  98                         c->host = xstrdup(value);
  99                 } else if (!strcmp(key, "path")) {
 100                         free(c->path);
 101                         c->path = xstrdup(value);
 102                 }
 103                 /*
 104                  * Ignore other lines; we don't know what they mean, but
 105                  * this future-proofs us when later versions of git do
 106                  * learn new lines, and the helpers are updated to match.
 107                  */
 108         }
 109
 110         strbuf_release(&line);
 111         return 0;
 112 }
 113
 114 static void credential_write_item(FILE *fp, const char *key, const char *value)
 115 {
 116         if (!value)
 117                 return;
 118         fprintf(fp, "%s=%s\n", key, value);
 119 }
 120
 121 static void credential_write(const struct credential *c, FILE *fp)
 122 {
 123         credential_write_item(fp, "protocol", c->protocol);
 124         credential_write_item(fp, "host", c->host);
 125         credential_write_item(fp, "path", c->path);
 126         credential_write_item(fp, "username", c->username);
 127         credential_write_item(fp, "password", c->password);
 128 }
 129
 130 static int run_credential_helper(struct credential *c,
 131                                  const char *cmd,
 132                                  int want_output)
 133 {
 134         struct child_process helper;
 135         const char *argv[] = { NULL, NULL };
 136         FILE *fp;
 137
 138         memset(&helper, 0, sizeof(helper));
 139         argv[0] = cmd;
 140         helper.argv = argv;
 141         helper.use_shell = 1;
 142         helper.in = -1;
 143         if (want_output)
 144                 helper.out = -1;
 145         else
 146                 helper.no_stdout = 1;
 147
 148         if (start_command(&helper) < 0)
 149                 return -1;
 150
 151         fp = xfdopen(helper.in, "w");
 152         credential_write(c, fp);
 153         fclose(fp);
 154
 155         if (want_output) {
 156                 int r;
 157                 fp = xfdopen(helper.out, "r");
 158                 r = credential_read(c, fp);
 159                 fclose(fp);
 160                 if (r < 0) {
 161                         finish_command(&helper);
 162                         return -1;
 163                 }
 164         }
 165
 166         if (finish_command(&helper))
 167                 return -1;
 168         return 0;
 169 }
 170
 171 static int credential_do(struct credential *c, const char *helper,
 172                          const char *operation)
 173 {
 174         struct strbuf cmd = STRBUF_INIT;
 175         int r;
 176
 177         if (helper[0] == '!')
 178                 strbuf_addstr(&cmd, helper + 1);
 179         else if (is_absolute_path(helper))
 180                 strbuf_addstr(&cmd, helper);
 181         else
 182                 strbuf_addf(&cmd, "git credential-%s", helper);
 183
 184         strbuf_addf(&cmd, " %s", operation);
 185         r = run_credential_helper(c, cmd.buf, !strcmp(operation, "get"));
 186
 187         strbuf_release(&cmd);
 188         return r;
 189 }
 190
 191 void credential_fill(struct credential *c)
 192 {
 193         int i;
 194
 195         if (c->username && c->password)
 196                 return;
 197
 198         for (i = 0; i < c->helpers.nr; i++) {
 199                 credential_do(c, c->helpers.items[i].string, "get");
 200                 if (c->username && c->password)
 201                         return;
 202         }
 203
 204         credential_getpass(c);
 205         if (!c->username && !c->password)
 206                 die("unable to get password from user");
 207 }
 208
 209 void credential_approve(struct credential *c)
 210 {
 211         int i;
 212
 213         if (c->approved)
 214                 return;
 215         if (!c->username || !c->password)
 216                 return;
 217
 218         for (i = 0; i < c->helpers.nr; i++)
 219                 credential_do(c, c->helpers.items[i].string, "store");
 220         c->approved = 1;
 221 }
 222
 223 void credential_reject(struct credential *c)
 224 {
 225         int i;
 226
 227         for (i = 0; i < c->helpers.nr; i++)
 228                 credential_do(c, c->helpers.items[i].string, "erase");
 229
 230         free(c->username);
 231         c->username = NULL;
 232         free(c->password);
 233         c->password = NULL;
 234         c->approved = 0;
 235 }
 236
 237 void credential_from_url(struct credential *c, const char *url)
 238 {
 239         const char *at, *colon, *cp, *slash, *host, *proto_end;
 240
 241         credential_clear(c);
 242
 243         /*
 244          * Match one of:
 245          *   (1) proto://<host>/...
 246          *   (2) proto://<user>@<host>/...
 247          *   (3) proto://<user>:<pass>@<host>/...
 248          */
 249         proto_end = strstr(url, "://");
 250         if (!proto_end)
 251                 return;
 252         cp = proto_end + 3;
 253         at = strchr(cp, '@');
 254         colon = strchr(cp, ':');
 255         slash = strchrnul(cp, '/');
 256
 257         if (!at || slash <= at) {
 258                 /* Case (1) */
 259                 host = cp;
 260         }
 261         else if (!colon || at <= colon) {
 262                 /* Case (2) */
 263                 c->username = url_decode_mem(cp, at - cp);
 264                 host = at + 1;
 265         } else {
 266                 /* Case (3) */
 267                 c->username = url_decode_mem(cp, colon - cp);
 268                 c->password = url_decode_mem(colon + 1, at - (colon + 1));
 269                 host = at + 1;
 270         }
 271
 272         if (proto_end - url > 0)
 273                 c->protocol = xmemdupz(url, proto_end - url);
 274         if (slash - host > 0)
 275                 c->host = url_decode_mem(host, slash - host);
 276         /* Trim leading and trailing slashes from path */
 277         while (*slash == '/')
 278                 slash++;
 279         if (*slash) {
 280                 char *p;
 281                 c->path = url_decode(slash);
 282                 p = c->path + strlen(c->path) - 1;
 283                 while (p > c->path && *p == '/')
 284                         *p-- = '\0';
 285         }
 286 }