static sign_key * loadhostkeys(const char * dsskeyfile,
const char * rsakeyfile) {
sign_key * hostkey;
TRACE(("enter loadhostkeys"));
hostkey = new_sign_key();
#ifdef DROPBEAR_RSA
(void)readhostkey(rsakeyfile, hostkey, DROPBEAR_SIGNKEY_RSA);
#endif
#ifdef DROPBEAR_DSS
(void)readhostkey(dsskeyfile, hostkey, DROPBEAR_SIGNKEY_DSS);
#endif
if ( 1
#ifdef DROPBEAR_DSS
&& hostkey->dsskey == NULL
#endif
#ifdef DROPBEAR_RSA
&& hostkey->rsakey == NULL
#endif
) {
dropbear_exit("No hostkeys available");
}
TRACE(("leave loadhostkeys"));
return hostkey;
}
int signkey_generate(enum signkey_type keytype, int bits, const char* filename)
{
sign_key * key = NULL;
buffer *buf = NULL;
int ret = DROPBEAR_FAILURE;
if (bits == 0)
{
bits = get_default_bits(keytype);
}
/* now we can generate the key */
key = new_sign_key();
seedrandom();
switch(keytype) {
#ifdef DROPBEAR_RSA
case DROPBEAR_SIGNKEY_RSA:
key->rsakey = gen_rsa_priv_key(bits);
break;
#endif
#ifdef DROPBEAR_DSS
case DROPBEAR_SIGNKEY_DSS:
key->dsskey = gen_dss_priv_key(bits);
break;
#endif
#ifdef DROPBEAR_ECDSA
case DROPBEAR_SIGNKEY_ECDSA_KEYGEN:
case DROPBEAR_SIGNKEY_ECDSA_NISTP521:
case DROPBEAR_SIGNKEY_ECDSA_NISTP384:
case DROPBEAR_SIGNKEY_ECDSA_NISTP256:
{
ecc_key *ecckey = gen_ecdsa_priv_key(bits);
keytype = ecdsa_signkey_type(ecckey);
*signkey_key_ptr(key, keytype) = ecckey;
}
break;
#endif
default:
dropbear_exit("Internal error");
}
seedrandom();
buf = buf_new(MAX_PRIVKEY_SIZE);
buf_put_priv_key(buf, key, keytype);
sign_key_free(key);
key = NULL;
buf_setpos(buf, 0);
ret = buf_writefile(buf, filename);
buf_burn(buf);
buf_free(buf);
buf = NULL;
return ret;
}
/* Handle a diffie-hellman key exchange reply. */
void recv_msg_kexdh_reply() {
DEF_MP_INT(dh_f);
sign_key *hostkey = NULL;
unsigned int type, keybloblen;
unsigned char* keyblob = NULL;
TRACE(("enter recv_msg_kexdh_reply"))
if (cli_ses.kex_state != KEXDH_INIT_SENT) {
dropbear_exit("Received out-of-order kexdhreply");
}
m_mp_init(&dh_f);
type = ses.newkeys->algo_hostkey;
TRACE(("type is %d", type))
hostkey = new_sign_key();
keybloblen = buf_getint(ses.payload);
keyblob = buf_getptr(ses.payload, keybloblen);
if (!ses.kexstate.donefirstkex) {
/* Only makes sense the first time */
checkhostkey(keyblob, keybloblen);
}
if (buf_get_pub_key(ses.payload, hostkey, &type) != DROPBEAR_SUCCESS) {
TRACE(("failed getting pubkey"))
dropbear_exit("Bad KEX packet");
}
if (buf_getmpint(ses.payload, &dh_f) != DROPBEAR_SUCCESS) {
TRACE(("failed getting mpint"))
dropbear_exit("Bad KEX packet");
}
kexdh_comb_key(cli_ses.dh_e, cli_ses.dh_x, &dh_f, hostkey);
mp_clear(&dh_f);
mp_clear_multi(cli_ses.dh_e, cli_ses.dh_x, NULL);
m_free(cli_ses.dh_e);
m_free(cli_ses.dh_x);
if (buf_verify(ses.payload, hostkey, ses.hash, SHA1_HASH_SIZE)
!= DROPBEAR_SUCCESS) {
dropbear_exit("Bad hostkey signature");
}
sign_key_free(hostkey);
hostkey = NULL;
send_msg_newkeys();
ses.requirenext = SSH_MSG_NEWKEYS;
TRACE(("leave recv_msg_kexdh_init"))
}
/* Must be called after syslog/etc is working */
static void loadhostkey(const char *keyfile, int fatal_duplicate) {
sign_key * read_key = new_sign_key();
enum signkey_type type = DROPBEAR_SIGNKEY_ANY;
if (readhostkey(keyfile, read_key, &type) == DROPBEAR_FAILURE) {
if (!svr_opts.delay_hostkey) {
dropbear_log(LOG_WARNING, "Failed loading %s", keyfile);
}
}
#ifdef DROPBEAR_RSA
if (type == DROPBEAR_SIGNKEY_RSA) {
loadhostkey_helper("RSA", (void**)&read_key->rsakey, (void**)&svr_opts.hostkey->rsakey, fatal_duplicate);
}
#endif
#ifdef DROPBEAR_DSS
if (type == DROPBEAR_SIGNKEY_DSS) {
loadhostkey_helper("DSS", (void**)&read_key->dsskey, (void**)&svr_opts.hostkey->dsskey, fatal_duplicate);
}
#endif
#ifdef DROPBEAR_ECDSA
#ifdef DROPBEAR_ECC_256
if (type == DROPBEAR_SIGNKEY_ECDSA_NISTP256) {
loadhostkey_helper("ECDSA256", (void**)&read_key->ecckey256, (void**)&svr_opts.hostkey->ecckey256, fatal_duplicate);
}
#endif
#ifdef DROPBEAR_ECC_384
if (type == DROPBEAR_SIGNKEY_ECDSA_NISTP384) {
loadhostkey_helper("ECDSA384", (void**)&read_key->ecckey384, (void**)&svr_opts.hostkey->ecckey384, fatal_duplicate);
}
#endif
#ifdef DROPBEAR_ECC_521
if (type == DROPBEAR_SIGNKEY_ECDSA_NISTP521) {
loadhostkey_helper("ECDSA521", (void**)&read_key->ecckey521, (void**)&svr_opts.hostkey->ecckey521, fatal_duplicate);
}
#endif
#endif /* DROPBEAR_ECDSA */
sign_key_free(read_key);
TRACE(("leave loadhostkey"))
}
static int printpubfile(const char* filename) {
buffer *buf = NULL;
sign_key *key = NULL;
enum signkey_type keytype;
int ret;
int err = DROPBEAR_FAILURE;
buf = buf_new(MAX_PRIVKEY_SIZE);
ret = buf_readfile(buf, filename);
if (ret != DROPBEAR_SUCCESS) {
fprintf(stderr, "Failed reading '%s'\n", filename);
goto out;
}
key = new_sign_key();
keytype = DROPBEAR_SIGNKEY_ANY;
buf_setpos(buf, 0);
ret = buf_get_priv_key(buf, key, &keytype);
if (ret == DROPBEAR_FAILURE) {
fprintf(stderr, "Bad key in '%s'\n", filename);
goto out;
}
printpubkey(key, keytype);
err = DROPBEAR_SUCCESS;
out:
buf_burn(buf);
buf_free(buf);
buf = NULL;
if (key) {
sign_key_free(key);
key = NULL;
}
return err;
}
/* Must be called after syslog/etc is working */
void loadhostkeys() {
int ret;
int type;
TRACE(("enter loadhostkeys"))
svr_opts.hostkey = new_sign_key();
#ifdef DROPBEAR_RSA
type = DROPBEAR_SIGNKEY_RSA;
ret = readhostkey(svr_opts.rsakeyfile, svr_opts.hostkey, &type);
if (ret == DROPBEAR_FAILURE) {
disablekey(DROPBEAR_SIGNKEY_RSA, svr_opts.rsakeyfile);
}
#endif
#ifdef DROPBEAR_DSS
type = DROPBEAR_SIGNKEY_DSS;
ret = readhostkey(svr_opts.dsskeyfile, svr_opts.hostkey, &type);
if (ret == DROPBEAR_FAILURE) {
disablekey(DROPBEAR_SIGNKEY_DSS, svr_opts.dsskeyfile);
}
#endif
if ( 1
#ifdef DROPBEAR_DSS
&& svr_opts.hostkey->dsskey == NULL
#endif
#ifdef DROPBEAR_RSA
&& svr_opts.hostkey->rsakey == NULL
#endif
) {
dropbear_exit("No hostkeys available");
}
TRACE(("leave loadhostkeys"))
}
void load_all_hostkeys() {
int i;
int disable_unset_keys = 1;
int any_keys = 0;
svr_opts.hostkey = new_sign_key();
for (i = 0; i < svr_opts.num_hostkey_files; i++) {
char *hostkey_file = svr_opts.hostkey_files[i];
loadhostkey(hostkey_file, 1);
m_free(hostkey_file);
}
#ifdef DROPBEAR_RSA
loadhostkey(RSA_PRIV_FILENAME, 0);
#endif
#ifdef DROPBEAR_DSS
loadhostkey(DSS_PRIV_FILENAME, 0);
#endif
#ifdef DROPBEAR_ECDSA
loadhostkey(ECDSA_PRIV_FILENAME, 0);
#endif
#ifdef DROPBEAR_DELAY_HOSTKEY
if (svr_opts.delay_hostkey) {
disable_unset_keys = 0;
}
#endif
#ifdef DROPBEAR_RSA
if (disable_unset_keys && !svr_opts.hostkey->rsakey) {
disablekey(DROPBEAR_SIGNKEY_RSA);
} else {
any_keys = 1;
}
#endif
#ifdef DROPBEAR_DSS
if (disable_unset_keys && !svr_opts.hostkey->dsskey) {
disablekey(DROPBEAR_SIGNKEY_DSS);
} else {
any_keys = 1;
}
#endif
#ifdef DROPBEAR_ECDSA
#ifdef DROPBEAR_ECC_256
if ((disable_unset_keys || ECDSA_DEFAULT_SIZE != 256)
&& !svr_opts.hostkey->ecckey256) {
disablekey(DROPBEAR_SIGNKEY_ECDSA_NISTP256);
} else {
any_keys = 1;
}
#endif
#ifdef DROPBEAR_ECC_384
if ((disable_unset_keys || ECDSA_DEFAULT_SIZE != 384)
&& !svr_opts.hostkey->ecckey384) {
disablekey(DROPBEAR_SIGNKEY_ECDSA_NISTP384);
} else {
any_keys = 1;
}
#endif
#ifdef DROPBEAR_ECC_521
if ((disable_unset_keys || ECDSA_DEFAULT_SIZE != 521)
&& !svr_opts.hostkey->ecckey521) {
disablekey(DROPBEAR_SIGNKEY_ECDSA_NISTP521);
} else {
any_keys = 1;
}
#endif
#endif /* DROPBEAR_ECDSA */
if (!any_keys) {
dropbear_exit("No hostkeys available. 'dropbear -R' may be useful or run dropbearkey.");
}
}
/* Handle a diffie-hellman key exchange reply. */
void recv_msg_kexdh_reply() {
sign_key *hostkey = NULL;
unsigned int type, keybloblen;
unsigned char* keyblob = NULL;
TRACE(("enter recv_msg_kexdh_reply"))
if (cli_ses.kex_state != KEXDH_INIT_SENT) {
dropbear_exit("Received out-of-order kexdhreply");
}
type = ses.newkeys->algo_hostkey;
TRACE(("type is %d", type))
hostkey = new_sign_key();
keybloblen = buf_getint(ses.payload);
keyblob = buf_getptr(ses.payload, keybloblen);
if (!ses.kexstate.donefirstkex) {
/* Only makes sense the first time */
checkhostkey(keyblob, keybloblen);
}
if (buf_get_pub_key(ses.payload, hostkey, &type) != DROPBEAR_SUCCESS) {
TRACE(("failed getting pubkey"))
dropbear_exit("Bad KEX packet");
}
switch (ses.newkeys->algo_kex->mode) {
case DROPBEAR_KEX_NORMAL_DH:
{
DEF_MP_INT(dh_f);
m_mp_init(&dh_f);
if (buf_getmpint(ses.payload, &dh_f) != DROPBEAR_SUCCESS) {
TRACE(("failed getting mpint"))
dropbear_exit("Bad KEX packet");
}
kexdh_comb_key(cli_ses.dh_param, &dh_f, hostkey);
mp_clear(&dh_f);
}
break;
case DROPBEAR_KEX_ECDH:
#ifdef DROPBEAR_ECDH
{
buffer *ecdh_qs = buf_getstringbuf(ses.payload);
kexecdh_comb_key(cli_ses.ecdh_param, ecdh_qs, hostkey);
buf_free(ecdh_qs);
}
#endif
break;
#ifdef DROPBEAR_CURVE25519
case DROPBEAR_KEX_CURVE25519:
{
buffer *ecdh_qs = buf_getstringbuf(ses.payload);
kexcurve25519_comb_key(cli_ses.curve25519_param, ecdh_qs, hostkey);
buf_free(ecdh_qs);
}
#endif
break;
}
if (cli_ses.dh_param) {
free_kexdh_param(cli_ses.dh_param);
cli_ses.dh_param = NULL;
}
#ifdef DROPBEAR_ECDH
if (cli_ses.ecdh_param) {
free_kexecdh_param(cli_ses.ecdh_param);
cli_ses.ecdh_param = NULL;
}
#endif
#ifdef DROPBEAR_CURVE25519
if (cli_ses.curve25519_param) {
free_kexcurve25519_param(cli_ses.curve25519_param);
cli_ses.curve25519_param = NULL;
}
#endif
cli_ses.param_kex_algo = NULL;
if (buf_verify(ses.payload, hostkey, ses.hash) != DROPBEAR_SUCCESS) {
dropbear_exit("Bad hostkey signature");
}
sign_key_free(hostkey);
hostkey = NULL;
send_msg_newkeys();
ses.requirenext[0] = SSH_MSG_NEWKEYS;
ses.requirenext[1] = 0;
TRACE(("leave recv_msg_kexdh_init"))
}
/* if skip_exist is set it will silently return if the key file exists */
int signkey_generate(enum signkey_type keytype, int bits, const char* filename, int skip_exist)
{
sign_key * key = NULL;
buffer *buf = NULL;
char *fn_temp = NULL;
int ret = DROPBEAR_FAILURE;
bits = signkey_generate_get_bits(keytype, bits);
/* now we can generate the key */
key = new_sign_key();
seedrandom();
switch(keytype) {
#if DROPBEAR_RSA
case DROPBEAR_SIGNKEY_RSA:
key->rsakey = gen_rsa_priv_key(bits);
break;
#endif
#if DROPBEAR_DSS
case DROPBEAR_SIGNKEY_DSS:
key->dsskey = gen_dss_priv_key(bits);
break;
#endif
#if DROPBEAR_ECDSA
case DROPBEAR_SIGNKEY_ECDSA_KEYGEN:
case DROPBEAR_SIGNKEY_ECDSA_NISTP521:
case DROPBEAR_SIGNKEY_ECDSA_NISTP384:
case DROPBEAR_SIGNKEY_ECDSA_NISTP256:
{
ecc_key *ecckey = gen_ecdsa_priv_key(bits);
keytype = ecdsa_signkey_type(ecckey);
*signkey_key_ptr(key, keytype) = ecckey;
}
break;
#endif
default:
dropbear_exit("Internal error");
}
seedrandom();
buf = buf_new(MAX_PRIVKEY_SIZE);
buf_put_priv_key(buf, key, keytype);
sign_key_free(key);
key = NULL;
buf_setpos(buf, 0);
fn_temp = m_malloc(strlen(filename) + 30);
snprintf(fn_temp, strlen(filename)+30, "%s.tmp%d", filename, getpid());
ret = buf_writefile(buf, fn_temp);
if (ret == DROPBEAR_FAILURE) {
goto out;
}
if (link(fn_temp, filename) < 0) {
/* If generating keys on connection (skipexist) it's OK to get EEXIST
- we probably just lost a race with another connection to generate the key */
if (!(skip_exist && errno == EEXIST)) {
dropbear_log(LOG_ERR, "Failed moving key file to %s: %s", filename,
strerror(errno));
/* XXX fallback to non-atomic copy for some filesystems? */
ret = DROPBEAR_FAILURE;
goto out;
}
}
out:
if (buf) {
buf_burn(buf);
buf_free(buf);
}
if (fn_temp) {
unlink(fn_temp);
m_free(fn_temp);
}
return ret;
}