static int
userauth_pubkey(Authctxt *authctxt)
{
Buffer b;
Key *key = NULL;
char *pkalg, *userstyle;
u_char *pkblob, *sig;
u_int alen, blen, slen;
int have_sig, pktype;
int authenticated = 0;
if (!authctxt->valid) {
debug2("userauth_pubkey: disabled because of invalid user");
return 0;
}
have_sig = packet_get_char();
if (datafellows & SSH_BUG_PKAUTH) {
debug2("userauth_pubkey: SSH_BUG_PKAUTH");
/* no explicit pkalg given */
pkblob = packet_get_string(&blen);
buffer_init(&b);
buffer_append(&b, pkblob, blen);
/* so we have to extract the pkalg from the pkblob */
pkalg = buffer_get_string(&b, &alen);
buffer_free(&b);
} else {
pkalg = packet_get_string(&alen);
pkblob = packet_get_string(&blen);
}
pktype = key_type_from_name(pkalg);
if (pktype == KEY_UNSPEC) {
/* this is perfectly legal */
logit("userauth_pubkey: unsupported public key algorithm: %s",
pkalg);
goto done;
}
key = key_from_blob(pkblob, blen);
if (key == NULL) {
error("userauth_pubkey: cannot decode key: %s", pkalg);
goto done;
}
if (key->type != pktype) {
error("userauth_pubkey: type mismatch for decoded key "
"(received %d, expected %d)", key->type, pktype);
goto done;
}
if (key_type_plain(key->type) == KEY_RSA &&
(datafellows & SSH_BUG_RSASIGMD5) != 0) {
logit("Refusing RSA key because client uses unsafe "
"signature scheme");
goto done;
}
if (auth2_userkey_already_used(authctxt, key)) {
logit("refusing previously-used %s key", key_type(key));
goto done;
}
if (match_pattern_list(sshkey_ssh_name(key), options.pubkey_key_types,
strlen(options.pubkey_key_types), 0) != 1) {
logit("%s: key type %s not in PubkeyAcceptedKeyTypes",
__func__, sshkey_ssh_name(key));
goto done;
}
if (have_sig) {
sig = packet_get_string(&slen);
packet_check_eom();
buffer_init(&b);
if (datafellows & SSH_OLD_SESSIONID) {
buffer_append(&b, session_id2, session_id2_len);
} else {
buffer_put_string(&b, session_id2, session_id2_len);
}
/* reconstruct packet */
buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST);
xasprintf(&userstyle, "%s%s%s", authctxt->user,
authctxt->style ? ":" : "",
authctxt->style ? authctxt->style : "");
buffer_put_cstring(&b, userstyle);
free(userstyle);
buffer_put_cstring(&b,
datafellows & SSH_BUG_PKSERVICE ?
"ssh-userauth" :
authctxt->service);
if (datafellows & SSH_BUG_PKAUTH) {
buffer_put_char(&b, have_sig);
} else {
buffer_put_cstring(&b, "publickey");
buffer_put_char(&b, have_sig);
buffer_put_cstring(&b, pkalg);
}
buffer_put_string(&b, pkblob, blen);
#ifdef DEBUG_PK
buffer_dump(&b);
#endif
pubkey_auth_info(authctxt, key, NULL);
/* test for correct signature */
authenticated = 0;
if (PRIVSEP(user_key_allowed(authctxt->pw, key)) &&
PRIVSEP(key_verify(key, sig, slen, buffer_ptr(&b),
buffer_len(&b))) == 1) {
authenticated = 1;
/* Record the successful key to prevent reuse */
auth2_record_userkey(authctxt, key);
key = NULL; /* Don't free below */
}
buffer_free(&b);
free(sig);
} else {
debug("test whether pkalg/pkblob are acceptable");
packet_check_eom();
/* XXX fake reply and always send PK_OK ? */
/*
* XXX this allows testing whether a user is allowed
* to login: if you happen to have a valid pubkey this
* message is sent. the message is NEVER sent at all
* if a user is not allowed to login. is this an
* issue? -markus
*/
if (PRIVSEP(user_key_allowed(authctxt->pw, key))) {
packet_start(SSH2_MSG_USERAUTH_PK_OK);
packet_put_string(pkalg, alen);
packet_put_string(pkblob, blen);
packet_send();
packet_write_wait();
authctxt->postponed = 1;
}
}
if (authenticated != 1)
auth_clear_options();
done:
debug2("userauth_pubkey: authenticated %d pkalg %s", authenticated, pkalg);
if (key != NULL)
key_free(key);
free(pkalg);
free(pkblob);
return authenticated;
}
int
mm_answer_keyallowed(int sock, struct sshbuf *m)
{
struct ssh *ssh = active_state; /* XXX */
struct sshkey *key;
char *cuser, *chost;
u_char *blob;
size_t bloblen;
enum mm_keytype type = 0;
int r, allowed = 0;
debug3("%s entering", __func__);
if ((r = sshbuf_get_u32(m, &type)) != 0 ||
(r = sshbuf_get_cstring(m, &cuser, NULL)) != 0 ||
(r = sshbuf_get_cstring(m, &chost, NULL)) != 0 ||
(r = sshbuf_get_string(m, &blob, &bloblen)) != 0)
fatal("%s: buffer error: %s", __func__, ssh_err(r));
if ((r = sshkey_from_blob(blob, bloblen, &key)) != 0)
fatal("%s: cannot parse key: %s", __func__, ssh_err(r));
if ((compat20 && type == MM_RSAHOSTKEY) ||
(!compat20 && type != MM_RSAHOSTKEY))
fatal("%s: key type and protocol mismatch", __func__);
if (key != NULL && authctxt->valid) {
/* These should not make it past the privsep child */
if (sshkey_type_plain(key->type) == KEY_RSA &&
(ssh->compat & SSH_BUG_RSASIGMD5) != 0)
fatal("%s: passed a SSH_BUG_RSASIGMD5 key", __func__);
switch (type) {
case MM_USERKEY:
allowed = options.pubkey_authentication &&
!auth2_userkey_already_used(authctxt, key) &&
match_pattern_list(sshkey_ssh_name(key),
options.pubkey_key_types,
strlen(options.pubkey_key_types), 0) == 1 &&
user_key_allowed(authctxt->pw, key);
pubkey_auth_info(authctxt, key, NULL);
auth_method = "publickey";
if (options.pubkey_authentication && allowed != 1)
auth_clear_options();
break;
case MM_HOSTKEY:
allowed = options.hostbased_authentication &&
match_pattern_list(sshkey_ssh_name(key),
options.hostbased_key_types,
strlen(options.hostbased_key_types), 0) == 1 &&
hostbased_key_allowed(authctxt->pw,
cuser, chost, key);
pubkey_auth_info(authctxt, key,
"client user \"%.100s\", client host \"%.100s\"",
cuser, chost);
auth_method = "hostbased";
break;
#ifdef WITH_SSH1
case MM_RSAHOSTKEY:
key->type = KEY_RSA1; /* XXX */
allowed = options.rhosts_rsa_authentication &&
auth_rhosts_rsa_key_allowed(authctxt->pw,
cuser, chost, key);
if (options.rhosts_rsa_authentication && allowed != 1)
auth_clear_options();
auth_method = "rsa";
break;
#endif
default:
fatal("%s: unknown key type %d", __func__, type);
break;
}
}
if (key != NULL)
sshkey_free(key);
/* clear temporarily storage (used by verify) */
monitor_reset_key_state();
if (allowed) {
/* Save temporarily for comparison in verify */
key_blob = blob;
key_bloblen = bloblen;
key_blobtype = type;
hostbased_cuser = cuser;
hostbased_chost = chost;
} else {
/* Log failed attempt */
auth_log(authctxt, 0, 0, auth_method, NULL);
free(blob);
free(cuser);
free(chost);
}
debug3("%s: key %p is %s",
__func__, key, allowed ? "allowed" : "not allowed");
sshbuf_reset(m);
if ((r = sshbuf_put_u32(m, allowed)) != 0 ||
(r = sshbuf_put_u32(m, forced_command != NULL)) != 0)
fatal("%s: buffer error: %s", __func__, ssh_err(r));
mm_request_send(sock, MONITOR_ANS_KEYALLOWED, m);
if (type == MM_RSAHOSTKEY)
monitor_permit(mon_dispatch, MONITOR_REQ_RSACHALLENGE, allowed);
return (0);
}
static int
userauth_pubkey(Authctxt *authctxt)
{
#ifdef WIN32_FIXME
int loginStat = 1;
char currentUser[MAX_PATH] = {0};
DWORD currentUserSize = sizeof(currentUser);
int targetIsCurrent = 0;
# ifdef USE_NTCREATETOKEN
int doOpenSSHVerify = 1;
# else
int doOpenSSHVerify = 0;
# endif
#endif
Buffer b;
Key *key = NULL;
char *pkalg, *userstyle;
u_char *pkblob, *sig;
u_int alen, blen, slen;
int have_sig, pktype;
int authenticated = 0;
if (!authctxt->valid) {
debug2("userauth_pubkey: disabled because of invalid user");
return 0;
}
have_sig = packet_get_char();
if (datafellows & SSH_BUG_PKAUTH) {
debug2("userauth_pubkey: SSH_BUG_PKAUTH");
/* no explicit pkalg given */
pkblob = packet_get_string(&blen);
buffer_init(&b);
buffer_append(&b, pkblob, blen);
/* so we have to extract the pkalg from the pkblob */
pkalg = buffer_get_string(&b, &alen);
buffer_free(&b);
} else {
pkalg = packet_get_string(&alen);
pkblob = packet_get_string(&blen);
}
pktype = key_type_from_name(pkalg);
if (pktype == KEY_UNSPEC) {
/* this is perfectly legal */
logit("userauth_pubkey: unsupported public key algorithm: %s",
pkalg);
goto done;
}
key = key_from_blob(pkblob, blen);
if (key == NULL) {
error("userauth_pubkey: cannot decode key: %s", pkalg);
goto done;
}
if (key->type != pktype) {
error("userauth_pubkey: type mismatch for decoded key "
"(received %d, expected %d)", key->type, pktype);
goto done;
}
if (key_type_plain(key->type) == KEY_RSA &&
(datafellows & SSH_BUG_RSASIGMD5) != 0) {
logit("Refusing RSA key because client uses unsafe "
"signature scheme");
goto done;
}
if (auth2_userkey_already_used(authctxt, key)) {
logit("refusing previously-used %s key", key_type(key));
goto done;
}
if (match_pattern_list(sshkey_ssh_name(key),
options.pubkey_key_types, 0) != 1) {
logit("%s: key type %s not in PubkeyAcceptedKeyTypes",
__func__, sshkey_ssh_name(key));
goto done;
}
if (have_sig) {
sig = packet_get_string(&slen);
packet_check_eom();
buffer_init(&b);
if (datafellows & SSH_OLD_SESSIONID) {
buffer_append(&b, session_id2, session_id2_len);
} else {
buffer_put_string(&b, session_id2, session_id2_len);
}
/* reconstruct packet */
buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST);
xasprintf(&userstyle, "%s%s%s", authctxt->user,
authctxt->style ? ":" : "",
authctxt->style ? authctxt->style : "");
buffer_put_cstring(&b, userstyle);
free(userstyle);
buffer_put_cstring(&b,
datafellows & SSH_BUG_PKSERVICE ?
"ssh-userauth" :
authctxt->service);
if (datafellows & SSH_BUG_PKAUTH) {
buffer_put_char(&b, have_sig);
} else {
buffer_put_cstring(&b, "publickey");
buffer_put_char(&b, have_sig);
buffer_put_cstring(&b, pkalg);
}
buffer_put_string(&b, pkblob, blen);
#ifdef DEBUG_PK
buffer_dump(&b);
#endif
pubkey_auth_info(authctxt, key, NULL);
/* test for correct signature */
authenticated = 0;
/*
* On pure win32 try to logon using lsa first.
*/
#ifdef WIN32_FIXME
authctxt -> hTokenLsa_ = NULL;
authctxt -> methoddata = NULL;
/*
* Retrieve name of current login user (i.e. sshd process owner).
*/
GetUserName(currentUser, ¤tUserSize);
/*
* Try to get token from lsa, but only if targetUser != currentUser.
* Owerthise we already have targetUser's token in current thread, so
* we only need key verify from original OpenSSH code.
*/
targetIsCurrent = (strcmp(currentUser, authctxt -> user) == 0);
if (targetIsCurrent)
{
doOpenSSHVerify = 1;
}
else
{
loginStat = LsaLogon(&authctxt -> hTokenLsa_, HomeDirLsaW,
authctxt -> user, pkblob, blen, sig, slen,
buffer_ptr(&b), buffer_len(&b), datafellows);
/*
* If lsa logon process success.
*/
if (loginStat == 0)
{
/*
* And user authorized OK.
*/
if (authctxt -> hTokenLsa_)
{
doOpenSSHVerify = 0;
/*
* This is part of openssh authorization needed for parsing
* 'options' block in key.
*/
authctxt -> pw -> pw_dir = GetHomeDir(authctxt -> user);
if (PRIVSEP(user_key_allowed(authctxt -> pw, key, 1))) // PRAGMA:TODO
{
authenticated = 1;
}
else
{
authenticated = 0;
}
buffer_free(&b);
free(sig);
}
}
}
if (doOpenSSHVerify)
{
/*
* If lsa fails, test for correct signature using openssh code.
*/
authctxt -> pw -> pw_dir = GetHomeDir(authctxt -> user);
if (PRIVSEP(user_key_allowed(authctxt->pw, key, 0)) //PRAGMA:TODO
&&
PRIVSEP(key_verify(key, sig, slen, buffer_ptr(&b), buffer_len(&b))) == 1)
{
authenticated = 1;
}
}
/*
* Original code.
*/
#else /* #ifdef WIN32_FIXME */
if (PRIVSEP(user_key_allowed(authctxt->pw, key, 1)) &&
PRIVSEP(key_verify(key, sig, slen, buffer_ptr(&b),
buffer_len(&b))) == 1) {
authenticated = 1;
/* Record the successful key to prevent reuse */
auth2_record_userkey(authctxt, key);
key = NULL; /* Don't free below */
}
buffer_free(&b);
free(sig);
#endif /* else #ifdef WIN32_FIXME. */
} else {
debug("test whether pkalg/pkblob are acceptable");
packet_check_eom();
/* XXX fake reply and always send PK_OK ? */
/*
* XXX this allows testing whether a user is allowed
* to login: if you happen to have a valid pubkey this
* message is sent. the message is NEVER sent at all
* if a user is not allowed to login. is this an
* issue? -markus
*/
#ifndef WIN32_FIXME
if (PRIVSEP(user_key_allowed(authctxt->pw, key, 0)))
#endif
{
packet_start(SSH2_MSG_USERAUTH_PK_OK);
packet_put_string(pkalg, alen);
packet_put_string(pkblob, blen);
packet_send();
packet_write_wait();
authctxt->postponed = 1;
}
}
if (authenticated != 1)
auth_clear_options();
done:
debug2("userauth_pubkey: authenticated %d pkalg %s", authenticated, pkalg);
if (key != NULL)
key_free(key);
free(pkalg);
free(pkblob);
return authenticated;
}
int
mm_answer_keyallowed(int sock, Buffer *m)
{
Key *key;
char *cuser, *chost;
u_char *blob;
u_int bloblen, pubkey_auth_attempt;
enum mm_keytype type = 0;
int allowed = 0;
debug3("%s entering", __func__);
type = buffer_get_int(m);
cuser = buffer_get_string(m, NULL);
chost = buffer_get_string(m, NULL);
blob = buffer_get_string(m, &bloblen);
pubkey_auth_attempt = buffer_get_int(m);
key = key_from_blob(blob, bloblen);
debug3("%s: key_from_blob: %p", __func__, key);
if (key != NULL && authctxt->valid) {
/* These should not make it past the privsep child */
if (key_type_plain(key->type) == KEY_RSA &&
(datafellows & SSH_BUG_RSASIGMD5) != 0)
fatal("%s: passed a SSH_BUG_RSASIGMD5 key", __func__);
switch (type) {
case MM_USERKEY:
allowed = options.pubkey_authentication &&
!auth2_userkey_already_used(authctxt, key) &&
match_pattern_list(sshkey_ssh_name(key),
options.pubkey_key_types, 0) == 1 &&
user_key_allowed(authctxt->pw, key,
pubkey_auth_attempt);
pubkey_auth_info(authctxt, key, NULL);
auth_method = "publickey";
if (options.pubkey_authentication &&
(!pubkey_auth_attempt || allowed != 1))
auth_clear_options();
break;
case MM_HOSTKEY:
allowed = options.hostbased_authentication &&
match_pattern_list(sshkey_ssh_name(key),
options.hostbased_key_types, 0) == 1 &&
hostbased_key_allowed(authctxt->pw,
cuser, chost, key);
pubkey_auth_info(authctxt, key,
"client user \"%.100s\", client host \"%.100s\"",
cuser, chost);
auth_method = "hostbased";
break;
default:
fatal("%s: unknown key type %d", __func__, type);
break;
}
}
debug3("%s: key %p is %s",
__func__, key, allowed ? "allowed" : "not allowed");
if (key != NULL)
key_free(key);
/* clear temporarily storage (used by verify) */
monitor_reset_key_state();
if (allowed) {
/* Save temporarily for comparison in verify */
key_blob = blob;
key_bloblen = bloblen;
key_blobtype = type;
hostbased_cuser = cuser;
hostbased_chost = chost;
} else {
/* Log failed attempt */
auth_log(authctxt, 0, 0, auth_method, NULL);
free(blob);
free(cuser);
free(chost);
}
buffer_clear(m);
buffer_put_int(m, allowed);
buffer_put_int(m, forced_command != NULL);
mm_request_send(sock, MONITOR_ANS_KEYALLOWED, m);
return (0);
}
