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");
  68 }
  69
  70 static void store_credential_file(const char *fn, struct credential *c)
  71 {
  72         struct strbuf buf = STRBUF_INIT;
  73
  74         strbuf_addf(&buf, "%s://", c->protocol);
  75         strbuf_addstr_urlencode(&buf, c->username, 1);
  76         strbuf_addch(&buf, ':');
  77         strbuf_addstr_urlencode(&buf, c->password, 1);
  78         strbuf_addch(&buf, '@');
  79         if (c->host)
  80                 strbuf_addstr_urlencode(&buf, c->host, 1);
  81         if (c->path) {
  82                 strbuf_addch(&buf, '/');
  83                 strbuf_addstr_urlencode(&buf, c->path, 0);
  84         }
  85
  86         rewrite_credential_file(fn, c, &buf);
  87         strbuf_release(&buf);
  88 }
  89
  90 static void store_credential(const struct string_list *fns, struct credential *c)
  91 {
  92         struct string_list_item *fn;
  93
  94         /*
  95          * Sanity check that what we are storing is actually sensible.
  96          * In particular, we can't make a URL without a protocol field.
  97          * Without either a host or pathname (depending on the scheme),
  98          * we have no primary key. And without a username and password,
  99          * we are not actually storing a credential.
 100          */
 101         if (!c->protocol || !(c->host || c->path) || !c->username || !c->password)
 102                 return;
 103
 104         for_each_string_list_item(fn, fns)
 105                 if (!access(fn->string, F_OK)) {
 106                         store_credential_file(fn->string, c);
 107                         return;
 108                 }
 109         /*
 110          * Write credential to the filename specified by fns->items[0], thus
 111          * creating it
 112          */
 113         if (fns->nr)
 114                 store_credential_file(fns->items[0].string, c);
 115 }
 116
 117 static void remove_credential(const struct string_list *fns, struct credential *c)
 118 {
 119         struct string_list_item *fn;
 120
 121         /*
 122          * Sanity check that we actually have something to match
 123          * against. The input we get is a restrictive pattern,
 124          * so technically a blank credential means "erase everything".
 125          * But it is too easy to accidentally send this, since it is equivalent
 126          * to empty input. So explicitly disallow it, and require that the
 127          * pattern have some actual content to match.
 128          */
 129         if (!c->protocol && !c->host && !c->path && !c->username)
 130                 return;
 131         for_each_string_list_item(fn, fns)
 132                 if (!access(fn->string, F_OK))
 133                         rewrite_credential_file(fn->string, c, NULL);
 134 }
 135
 136 static void lookup_credential(const struct string_list *fns, struct credential *c)
 137 {
 138         struct string_list_item *fn;
 139
 140         for_each_string_list_item(fn, fns)
 141                 if (parse_credential_file(fn->string, c, print_entry, NULL))
 142                         return; /* Found credential */
 143 }
 144
 145 int main(int argc, char **argv)
 146 {
 147         const char * const usage[] = {
 148                 "git credential-store [<options>] <action>",
 149                 NULL
 150         };
 151         const char *op;
 152         struct credential c = CREDENTIAL_INIT;
 153         struct string_list fns = STRING_LIST_INIT_DUP;
 154         char *file = NULL;
 155         struct option options[] = {
 156                 OPT_STRING(0, "file", &file, "path",
 157                            "fetch and store credentials in <path>"),
 158                 OPT_END()
 159         };
 160
 161         umask(077);
 162
 163         argc = parse_options(argc, (const char **)argv, NULL, options, usage, 0);
 164         if (argc != 1)
 165                 usage_with_options(usage, options);
 166         op = argv[0];
 167
 168         if (file) {
 169                 string_list_append(&fns, file);
 170         } else {
 171                 if ((file = expand_user_path("~/.git-credentials")))
 172                         string_list_append_nodup(&fns, file);
 173                 file = xdg_config_home("credentials");
 174                 if (file)
 175                         string_list_append_nodup(&fns, file);
 176         }
 177         if (!fns.nr)
 178                 die("unable to set up default path; use --file");
 179
 180         if (credential_read(&c, stdin) < 0)
 181                 die("unable to read credential");
 182
 183         if (!strcmp(op, "get"))
 184                 lookup_credential(&fns, &c);
 185         else if (!strcmp(op, "erase"))
 186                 remove_credential(&fns, &c);
 187         else if (!strcmp(op, "store"))
 188                 store_credential(&fns, &c);
 189         else
 190                 ; /* Ignore unknown operation. */
 191
 192         string_list_clear(&fns, 0);
 193         return 0;
 194 }