| /* |
| * Dropbear SSH |
| * |
| * Copyright (c) 2002,2003 Matt Johnston |
| * Copyright (c) 2004 by Mihnea Stoenescu |
| * All rights reserved. |
| * |
| * Permission is hereby granted, free of charge, to any person obtaining a copy |
| * of this software and associated documentation files (the "Software"), to deal |
| * in the Software without restriction, including without limitation the rights |
| * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell |
| * copies of the Software, and to permit persons to whom the Software is |
| * furnished to do so, subject to the following conditions: |
| * |
| * The above copyright notice and this permission notice shall be included in |
| * all copies or substantial portions of the Software. |
| * |
| * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR |
| * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
| * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE |
| * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER |
| * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, |
| * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE |
| * SOFTWARE. */ |
| |
| #include "includes.h" |
| #include "buffer.h" |
| #include "dbutil.h" |
| #include "session.h" |
| #include "ssh.h" |
| #include "runopts.h" |
| #include "auth.h" |
| #include "agentfwd.h" |
| |
| #ifdef ENABLE_CLI_PUBKEY_AUTH |
| static void send_msg_userauth_pubkey(sign_key *key, int type, int realsign); |
| |
| /* Called when we receive a SSH_MSG_USERAUTH_FAILURE for a pubkey request. |
| * We use it to remove the key we tried from the list */ |
| void cli_pubkeyfail() { |
| m_list_elem *iter; |
| for (iter = cli_opts.privkeys->first; iter; iter = iter->next) { |
| sign_key *iter_key = (sign_key*)iter->item; |
| |
| if (iter_key == cli_ses.lastprivkey) |
| { |
| /* found the failing key */ |
| list_remove(iter); |
| sign_key_free(iter_key); |
| cli_ses.lastprivkey = NULL; |
| return; |
| } |
| } |
| } |
| |
| void recv_msg_userauth_pk_ok() { |
| m_list_elem *iter; |
| buffer* keybuf = NULL; |
| char* algotype = NULL; |
| unsigned int algolen; |
| enum signkey_type keytype; |
| unsigned int remotelen; |
| |
| TRACE(("enter recv_msg_userauth_pk_ok")) |
| |
| algotype = buf_getstring(ses.payload, &algolen); |
| keytype = signkey_type_from_name(algotype, algolen); |
| TRACE(("recv_msg_userauth_pk_ok: type %d", keytype)) |
| m_free(algotype); |
| |
| keybuf = buf_new(MAX_PUBKEY_SIZE); |
| |
| remotelen = buf_getint(ses.payload); |
| |
| /* Iterate through our keys, find which one it was that matched, and |
| * send a real request with that key */ |
| for (iter = cli_opts.privkeys->first; iter; iter = iter->next) { |
| sign_key *key = (sign_key*)iter->item; |
| if (key->type != keytype) { |
| /* Types differed */ |
| TRACE(("types differed")) |
| continue; |
| } |
| |
| /* Now we compare the contents of the key */ |
| keybuf->pos = keybuf->len = 0; |
| buf_put_pub_key(keybuf, key, keytype); |
| buf_setpos(keybuf, 0); |
| buf_incrpos(keybuf, 4); /* first int is the length of the remainder (ie |
| remotelen) which has already been taken from |
| the remote buffer */ |
| |
| |
| if (keybuf->len-4 != remotelen) { |
| TRACE(("lengths differed: localh %d remote %d", keybuf->len, remotelen)) |
| /* Lengths differed */ |
| continue; |
| } |
| if (memcmp(buf_getptr(keybuf, remotelen), |
| buf_getptr(ses.payload, remotelen), remotelen) != 0) { |
| /* Data didn't match this key */ |
| TRACE(("data differed")) |
| continue; |
| } |
| |
| /* Success */ |
| break; |
| } |
| buf_free(keybuf); |
| |
| if (iter != NULL) { |
| TRACE(("matching key")) |
| /* XXX TODO: if it's an encrypted key, here we ask for their |
| * password */ |
| send_msg_userauth_pubkey((sign_key*)iter->item, keytype, 1); |
| } else { |
| TRACE(("That was whacky. We got told that a key was valid, but it didn't match our list. Sounds like dodgy code on Dropbear's part")) |
| } |
| |
| TRACE(("leave recv_msg_userauth_pk_ok")) |
| } |
| |
| void cli_buf_put_sign(buffer* buf, sign_key *key, int type, |
| buffer *data_buf) { |
| #ifdef ENABLE_CLI_AGENTFWD |
| if (key->source == SIGNKEY_SOURCE_AGENT) { |
| /* Format the agent signature ourselves, as buf_put_sign would. */ |
| buffer *sigblob; |
| sigblob = buf_new(MAX_PUBKEY_SIZE); |
| agent_buf_sign(sigblob, key, data_buf); |
| buf_putbufstring(buf, sigblob); |
| buf_free(sigblob); |
| } else |
| #endif /* ENABLE_CLI_AGENTFWD */ |
| { |
| buf_put_sign(buf, key, type, data_buf); |
| } |
| } |
| |
| /* TODO: make it take an agent reference to use as well */ |
| static void send_msg_userauth_pubkey(sign_key *key, int type, int realsign) { |
| |
| const char *algoname = NULL; |
| unsigned int algolen; |
| buffer* sigbuf = NULL; |
| |
| TRACE(("enter send_msg_userauth_pubkey")) |
| CHECKCLEARTOWRITE(); |
| |
| buf_putbyte(ses.writepayload, SSH_MSG_USERAUTH_REQUEST); |
| |
| buf_putstring(ses.writepayload, cli_opts.username, |
| strlen(cli_opts.username)); |
| |
| buf_putstring(ses.writepayload, SSH_SERVICE_CONNECTION, |
| SSH_SERVICE_CONNECTION_LEN); |
| |
| buf_putstring(ses.writepayload, AUTH_METHOD_PUBKEY, |
| AUTH_METHOD_PUBKEY_LEN); |
| |
| buf_putbyte(ses.writepayload, realsign); |
| |
| algoname = signkey_name_from_type(type, &algolen); |
| |
| buf_putstring(ses.writepayload, algoname, algolen); |
| buf_put_pub_key(ses.writepayload, key, type); |
| |
| if (realsign) { |
| TRACE(("realsign")) |
| /* We put the signature as well - this contains string(session id), then |
| * the contents of the write payload to this point */ |
| sigbuf = buf_new(4 + ses.session_id->len + ses.writepayload->len); |
| buf_putbufstring(sigbuf, ses.session_id); |
| buf_putbytes(sigbuf, ses.writepayload->data, ses.writepayload->len); |
| cli_buf_put_sign(ses.writepayload, key, type, sigbuf); |
| buf_free(sigbuf); /* Nothing confidential in the buffer */ |
| } |
| |
| encrypt_packet(); |
| TRACE(("leave send_msg_userauth_pubkey")) |
| } |
| |
| /* Returns 1 if a key was tried */ |
| int cli_auth_pubkey() { |
| |
| TRACE(("enter cli_auth_pubkey")) |
| |
| #ifdef ENABLE_CLI_AGENTFWD |
| if (!cli_opts.agent_keys_loaded) { |
| /* get the list of available keys from the agent */ |
| cli_load_agent_keys(cli_opts.privkeys); |
| cli_opts.agent_keys_loaded = 1; |
| } |
| #endif |
| |
| if (cli_opts.privkeys->first) { |
| sign_key * key = (sign_key*)cli_opts.privkeys->first->item; |
| /* Send a trial request */ |
| send_msg_userauth_pubkey(key, key->type, 0); |
| cli_ses.lastprivkey = key; |
| TRACE(("leave cli_auth_pubkey-success")) |
| return 1; |
| } else { |
| /* no more keys left */ |
| TRACE(("leave cli_auth_pubkey-failure")) |
| return 0; |
| } |
| } |
| |
| void cli_auth_pubkey_cleanup() { |
| |
| #ifdef ENABLE_CLI_AGENTFWD |
| m_close(cli_opts.agent_fd); |
| cli_opts.agent_fd = -1; |
| #endif |
| |
| while (cli_opts.privkeys->first) { |
| sign_key * key = list_remove(cli_opts.privkeys->first); |
| sign_key_free(key); |
| } |
| } |
| #endif /* Pubkey auth */ |