Key *
key_load_private(const char *filename, const char *passphrase,
char **commentp)
{
Key *pub, *prv;
int fd;
fd = open(filename, O_RDONLY);
if (fd < 0)
return NULL;
if (!key_perm_ok(fd, filename)) {
error("bad permissions: ignore key: %s", filename);
close(fd);
return NULL;
}
pub = key_load_public_rsa1(fd, filename, commentp);
lseek(fd, (off_t) 0, SEEK_SET); /* rewind */
if (pub == NULL) {
/* closes fd */
prv = key_load_private_pem(fd, KEY_UNSPEC, passphrase, NULL);
/* use the filename as a comment for PEM */
if (commentp && prv)
*commentp = xstrdup(filename);
} else {
/* it's a SSH v1 key if the public key part is readable */
key_free(pub);
/* closes fd */
prv = key_load_private_rsa1(fd, filename, passphrase, NULL);
}
return prv;
}
Key *
key_load_private_type(int type, const char *filename, const char *passphrase,
char **commentp)
{
int fd;
fd = open(filename, O_RDONLY);
if (fd < 0)
return NULL;
if (!key_perm_ok(fd, filename)) {
error("bad permissions: ignore key: %s", filename);
close(fd);
return NULL;
}
switch (type) {
case KEY_RSA1:
return key_load_private_rsa1(fd, filename, passphrase,
commentp);
/* closes fd */
break;
case KEY_DSA:
case KEY_RSA:
case KEY_UNSPEC:
return key_load_private_pem(fd, type, passphrase, commentp);
/* closes fd */
break;
default:
close(fd);
break;
}
return NULL;
}
int
main(int argc, char **argv)
{
Buffer b;
Options options;
#define NUM_KEYTYPES 3
Key *keys[NUM_KEYTYPES], *key = NULL;
struct passwd *pw;
int key_fd[NUM_KEYTYPES], i, found, version = 2, fd;
u_char *signature, *data;
char *host;
u_int slen, dlen;
u_int32_t rnd[256];
/* Ensure that stdin and stdout are connected */
if ((fd = open(_PATH_DEVNULL, O_RDWR)) < 2)
exit(1);
/* Leave /dev/null fd iff it is attached to stderr */
if (fd > 2)
close(fd);
i = 0;
key_fd[i++] = open(_PATH_HOST_DSA_KEY_FILE, O_RDONLY);
key_fd[i++] = open(_PATH_HOST_ECDSA_KEY_FILE, O_RDONLY);
key_fd[i++] = open(_PATH_HOST_RSA_KEY_FILE, O_RDONLY);
original_real_uid = getuid(); /* XXX readconf.c needs this */
if ((pw = getpwuid(original_real_uid)) == NULL)
fatal("getpwuid failed");
pw = pwcopy(pw);
permanently_set_uid(pw);
#ifdef DEBUG_SSH_KEYSIGN
log_init("ssh-keysign", SYSLOG_LEVEL_DEBUG3, SYSLOG_FACILITY_AUTH, 0);
#endif
/* verify that ssh-keysign is enabled by the admin */
initialize_options(&options);
(void)read_config_file(_PATH_HOST_CONFIG_FILE, "", &options, 0);
fill_default_options(&options);
if (options.enable_ssh_keysign != 1)
fatal("ssh-keysign not enabled in %s",
_PATH_HOST_CONFIG_FILE);
for (i = found = 0; i < NUM_KEYTYPES; i++) {
if (key_fd[i] != -1)
found = 1;
}
if (found == 0)
fatal("could not open any host key");
OpenSSL_add_all_algorithms();
for (i = 0; i < 256; i++)
rnd[i] = arc4random();
RAND_seed(rnd, sizeof(rnd));
found = 0;
for (i = 0; i < NUM_KEYTYPES; i++) {
keys[i] = NULL;
if (key_fd[i] == -1)
continue;
keys[i] = key_load_private_pem(key_fd[i], KEY_UNSPEC,
NULL, NULL);
close(key_fd[i]);
if (keys[i] != NULL)
found = 1;
}
if (!found)
fatal("no hostkey found");
buffer_init(&b);
if (ssh_msg_recv(STDIN_FILENO, &b) < 0)
fatal("ssh_msg_recv failed");
if (buffer_get_char(&b) != version)
fatal("bad version");
fd = buffer_get_int(&b);
if ((fd == STDIN_FILENO) || (fd == STDOUT_FILENO))
fatal("bad fd");
if ((host = get_local_name(fd)) == NULL)
fatal("cannot get local name for fd");
data = buffer_get_string(&b, &dlen);
if (valid_request(pw, host, &key, data, dlen) < 0)
fatal("not a valid request");
xfree(host);
found = 0;
for (i = 0; i < NUM_KEYTYPES; i++) {
if (keys[i] != NULL &&
key_equal_public(key, keys[i])) {
found = 1;
break;
}
}
if (!found)
fatal("no matching hostkey found");
if (key_sign(keys[i], &signature, &slen, data, dlen) != 0)
fatal("key_sign failed");
xfree(data);
/* send reply */
buffer_clear(&b);
buffer_put_string(&b, signature, slen);
if (ssh_msg_send(STDOUT_FILENO, version, &b) == -1)
fatal("ssh_msg_send failed");
return (0);
}
