credential-store.c

   1 #include "cache.h"
   2 #include "lockfile.h"
   3 #include "credential.h"
   4 #include "string-list.h"
   5 #include "parse-options.h"
   6
   7 static struct lock_file credential_lock;
   8
   9 static int parse_credential_file(const char *fn,
  10                                   struct credential *c,
  11                                   void (*match_cb)(struct credential *),
  12                                   void (*other_cb)(struct strbuf *))
  13 {
  14         FILE *fh;
  15         struct strbuf line = STRBUF_INIT;
  16         struct credential entry = CREDENTIAL_INIT;
  17         int found_credential = 0;
  18
  19         fh = fopen(fn, "r");
  20         if (!fh) {
  21                 if (errno != ENOENT && errno != EACCES)
  22                         die_errno("unable to open %s", fn);
  23                 return found_credential;
  24         }
  25
  26         while (strbuf_getline(&line, fh, '\n') != EOF) {
  27                 credential_from_url(&entry, line.buf);
  28                 if (entry.username && entry.password &&
  29                     credential_match(c, &entry)) {
  30                         found_credential = 1;
  31                         if (match_cb) {
  32                                 match_cb(&entry);
  33                                 break;
  34                         }
  35                 }
  36                 else if (other_cb)
  37                         other_cb(&line);
  38         }
  39
  40         credential_clear(&entry);
  41         strbuf_release(&line);
  42         fclose(fh);
  43         return found_credential;
  44 }
  45
  46 static void print_entry(struct credential *c)
  47 {
  48         printf("username=%s\n", c->username);
  49         printf("password=%s\n", c->password);
  50 }
  51
  52 static void print_line(struct strbuf *buf)
  53 {
  54         strbuf_addch(buf, '\n');
  55         write_or_die(get_lock_file_fd(&credential_lock), buf->buf, buf->len);
  56 }
  57
  58 static void rewrite_credential_file(const char *fn, struct credential *c,
  59                                     struct strbuf *extra)
  60 {
  61         if (hold_lock_file_for_update(&credential_lock, fn, 0) < 0)
  62                 die_errno("unable to get credential storage lock");
  63         if (extra)
  64                 print_line(extra);
  65         parse_credential_file(fn, c, NULL, print_line);
  66         if (commit_lock_file(&credential_lock) < 0)
  67                 die_errno("unable to write credential store: %s",
  68                           strerror(errno));
  69 }
  70
  71 static void store_credential_file(const char *fn, struct credential *c)
  72 {
  73         struct strbuf buf = STRBUF_INIT;
  74
  75         strbuf_addf(&buf, "%s://", c->protocol);
  76         strbuf_addstr_urlencode(&buf, c->username, 1);
  77         strbuf_addch(&buf, ':');
  78         strbuf_addstr_urlencode(&buf, c->password, 1);
  79         strbuf_addch(&buf, '@');
  80         if (c->host)
  81                 strbuf_addstr_urlencode(&buf, c->host, 1);
  82         if (c->path) {
  83                 strbuf_addch(&buf, '/');
  84                 strbuf_addstr_urlencode(&buf, c->path, 0);
  85         }
  86
  87         rewrite_credential_file(fn, c, &buf);
  88         strbuf_release(&buf);
  89 }
  90
  91 static void store_credential(const struct string_list *fns, struct credential *c)
  92 {
  93         struct string_list_item *fn;
  94
  95         /*
  96          * Sanity check that what we are storing is actually sensible.
  97          * In particular, we can't make a URL without a protocol field.
  98          * Without either a host or pathname (depending on the scheme),
  99          * we have no primary key. And without a username and password,
 100          * we are not actually storing a credential.
 101          */
 102         if (!c->protocol || !(c->host || c->path) || !c->username || !c->password)
 103                 return;
 104
 105         for_each_string_list_item(fn, fns)
 106                 if (!access(fn->string, F_OK)) {
 107                         store_credential_file(fn->string, c);
 108                         return;
 109                 }
 110         /*
 111          * Write credential to the filename specified by fns->items[0], thus
 112          * creating it
 113          */
 114         if (fns->nr)
 115                 store_credential_file(fns->items[0].string, c);
 116 }
 117
 118 static void remove_credential(const struct string_list *fns, struct credential *c)
 119 {
 120         struct string_list_item *fn;
 121
 122         /*
 123          * Sanity check that we actually have something to match
 124          * against. The input we get is a restrictive pattern,
 125          * so technically a blank credential means "erase everything".
 126          * But it is too easy to accidentally send this, since it is equivalent
 127          * to empty input. So explicitly disallow it, and require that the
 128          * pattern have some actual content to match.
 129          */
 130         if (!c->protocol && !c->host && !c->path && !c->username)
 131                 return;
 132         for_each_string_list_item(fn, fns)
 133                 if (!access(fn->string, F_OK))
 134                         rewrite_credential_file(fn->string, c, NULL);
 135 }
 136
 137 static void lookup_credential(const struct string_list *fns, struct credential *c)
 138 {
 139         struct string_list_item *fn;
 140
 141         for_each_string_list_item(fn, fns)
 142                 if (parse_credential_file(fn->string, c, print_entry, NULL))
 143                         return; /* Found credential */
 144 }
 145
 146 int main(int argc, char **argv)
 147 {
 148         const char * const usage[] = {
 149                 "git credential-store [<options>] <action>",
 150                 NULL
 151         };
 152         const char *op;
 153         struct credential c = CREDENTIAL_INIT;
 154         struct string_list fns = STRING_LIST_INIT_DUP;
 155         char *file = NULL;
 156         struct option options[] = {
 157                 OPT_STRING(0, "file", &file, "path",
 158                            "fetch and store credentials in <path>"),
 159                 OPT_END()
 160         };
 161
 162         umask(077);
 163
 164         argc = parse_options(argc, (const char **)argv, NULL, options, usage, 0);
 165         if (argc != 1)
 166                 usage_with_options(usage, options);
 167         op = argv[0];
 168
 169         if (file) {
 170                 string_list_append(&fns, file);
 171         } else {
 172                 if ((file = expand_user_path("~/.git-credentials")))
 173                         string_list_append_nodup(&fns, file);
 174                 file = xdg_config_home("credentials");
 175                 if (file)
 176                         string_list_append_nodup(&fns, file);
 177         }
 178         if (!fns.nr)
 179                 die("unable to set up default path; use --file");
 180
 181         if (credential_read(&c, stdin) < 0)
 182                 die("unable to read credential");
 183
 184         if (!strcmp(op, "get"))
 185                 lookup_credential(&fns, &c);
 186         else if (!strcmp(op, "erase"))
 187                 remove_credential(&fns, &c);
 188         else if (!strcmp(op, "store"))
 189                 store_credential(&fns, &c);
 190         else
 191                 ; /* Ignore unknown operation. */
 192
 193         string_list_clear(&fns, 0);
 194         return 0;
 195 }