Mercurial > dropbear
view cli-auth.c @ 766:d1575fdc29a6 ecc
start on ecdsa keys
author | Matt Johnston <matt@ucc.asn.au> |
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date | Tue, 09 Apr 2013 00:36:04 +0800 |
parents | 983a817f8e41 |
children | 714b9106e335 |
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/* * 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 "session.h" #include "auth.h" #include "dbutil.h" #include "buffer.h" #include "ssh.h" #include "packet.h" #include "runopts.h" void cli_authinitialise() { memset(&ses.authstate, 0, sizeof(ses.authstate)); } /* Send a "none" auth request to get available methods */ void cli_auth_getmethods() { TRACE(("enter cli_auth_getmethods")) 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, "none", 4); /* 'none' method */ encrypt_packet(); TRACE(("leave cli_auth_getmethods")) } void recv_msg_userauth_banner() { unsigned char* banner = NULL; unsigned int bannerlen; unsigned int i, linecount; TRACE(("enter recv_msg_userauth_banner")) if (ses.authstate.authdone) { TRACE(("leave recv_msg_userauth_banner: banner after auth done")) return; } banner = buf_getstring(ses.payload, &bannerlen); buf_eatstring(ses.payload); /* The language string */ if (bannerlen > MAX_BANNER_SIZE) { TRACE(("recv_msg_userauth_banner: bannerlen too long: %d", bannerlen)) goto out; } cleantext(banner); /* Limit to 25 lines */ linecount = 1; for (i = 0; i < bannerlen; i++) { if (banner[i] == '\n') { if (linecount >= MAX_BANNER_LINES) { banner[i] = '\0'; break; } linecount++; } } fprintf(stderr, "%s\n", banner); out: m_free(banner); TRACE(("leave recv_msg_userauth_banner")) } /* This handles the message-specific types which * all have a value of 60. These are * SSH_MSG_USERAUTH_PASSWD_CHANGEREQ, * SSH_MSG_USERAUTH_PK_OK, & * SSH_MSG_USERAUTH_INFO_REQUEST. */ void recv_msg_userauth_specific_60() { #ifdef ENABLE_CLI_PUBKEY_AUTH if (cli_ses.lastauthtype == AUTH_TYPE_PUBKEY) { recv_msg_userauth_pk_ok(); return; } #endif #ifdef ENABLE_CLI_INTERACT_AUTH if (cli_ses.lastauthtype == AUTH_TYPE_INTERACT) { recv_msg_userauth_info_request(); return; } #endif #ifdef ENABLE_CLI_PASSWORD_AUTH if (cli_ses.lastauthtype == AUTH_TYPE_PASSWORD) { /* Eventually there could be proper password-changing * support. However currently few servers seem to * implement it, and password auth is last-resort * regardless - keyboard-interactive is more likely * to be used anyway. */ dropbear_close("Your password has expired."); } #endif dropbear_exit("Unexpected userauth packet"); } void recv_msg_userauth_failure() { unsigned char * methods = NULL; unsigned char * tok = NULL; unsigned int methlen = 0; unsigned int partial = 0; unsigned int i = 0; TRACE(("<- MSG_USERAUTH_FAILURE")) TRACE(("enter recv_msg_userauth_failure")) if (cli_ses.state != USERAUTH_REQ_SENT) { /* Perhaps we should be more fatal? */ dropbear_exit("Unexpected userauth failure"); } #ifdef ENABLE_CLI_PUBKEY_AUTH /* If it was a pubkey auth request, we should cross that key * off the list. */ if (cli_ses.lastauthtype == AUTH_TYPE_PUBKEY) { cli_pubkeyfail(); } #endif #ifdef ENABLE_CLI_INTERACT_AUTH /* If we get a failure message for keyboard interactive without * receiving any request info packet, then we don't bother trying * keyboard interactive again */ if (cli_ses.lastauthtype == AUTH_TYPE_INTERACT && !cli_ses.interact_request_received) { TRACE(("setting auth_interact_failed = 1")) cli_ses.auth_interact_failed = 1; } #endif cli_ses.lastauthtype = AUTH_TYPE_NONE; methods = buf_getstring(ses.payload, &methlen); partial = buf_getbool(ses.payload); if (partial) { dropbear_log(LOG_INFO, "Authentication partially succeeded, more attempts required"); } else { ses.authstate.failcount++; } TRACE(("Methods (len %d): '%s'", methlen, methods)) ses.authstate.authdone=0; ses.authstate.authtypes=0; /* Split with nulls rather than commas */ for (i = 0; i < methlen; i++) { if (methods[i] == ',') { methods[i] = '\0'; } } tok = methods; /* tok stores the next method we'll compare */ for (i = 0; i <= methlen; i++) { if (methods[i] == '\0') { TRACE(("auth method '%s'", tok)) #ifdef ENABLE_CLI_PUBKEY_AUTH if (strncmp(AUTH_METHOD_PUBKEY, tok, AUTH_METHOD_PUBKEY_LEN) == 0) { ses.authstate.authtypes |= AUTH_TYPE_PUBKEY; } #endif #ifdef ENABLE_CLI_INTERACT_AUTH if (strncmp(AUTH_METHOD_INTERACT, tok, AUTH_METHOD_INTERACT_LEN) == 0) { ses.authstate.authtypes |= AUTH_TYPE_INTERACT; } #endif #ifdef ENABLE_CLI_PASSWORD_AUTH if (strncmp(AUTH_METHOD_PASSWORD, tok, AUTH_METHOD_PASSWORD_LEN) == 0) { ses.authstate.authtypes |= AUTH_TYPE_PASSWORD; } #endif tok = &methods[i+1]; /* Must make sure we don't use it after the last loop, since it'll point to something undefined */ } } m_free(methods); cli_ses.state = USERAUTH_FAIL_RCVD; TRACE(("leave recv_msg_userauth_failure")) } void recv_msg_userauth_success() { TRACE(("received msg_userauth_success")) /* Note: in delayed-zlib mode, setting authdone here * will enable compression in the transport layer */ ses.authstate.authdone = 1; cli_ses.state = USERAUTH_SUCCESS_RCVD; cli_ses.lastauthtype = AUTH_TYPE_NONE; #ifdef ENABLE_CLI_PUBKEY_AUTH cli_auth_pubkey_cleanup(); #endif } void cli_auth_try() { int finished = 0; TRACE(("enter cli_auth_try")) CHECKCLEARTOWRITE(); /* Order to try is pubkey, interactive, password. * As soon as "finished" is set for one, we don't do any more. */ #ifdef ENABLE_CLI_PUBKEY_AUTH if (ses.authstate.authtypes & AUTH_TYPE_PUBKEY) { finished = cli_auth_pubkey(); cli_ses.lastauthtype = AUTH_TYPE_PUBKEY; } #endif #ifdef ENABLE_CLI_INTERACT_AUTH if (ses.keys->trans.algo_crypt->cipherdesc == NULL) { fprintf(stderr, "Sorry, I won't let you use interactive auth unencrypted.\n"); } else if (!finished && ses.authstate.authtypes & AUTH_TYPE_INTERACT) { if (cli_ses.auth_interact_failed) { finished = 0; } else { cli_auth_interactive(); cli_ses.lastauthtype = AUTH_TYPE_INTERACT; finished = 1; } } #endif #ifdef ENABLE_CLI_PASSWORD_AUTH if (ses.keys->trans.algo_crypt->cipherdesc == NULL) { fprintf(stderr, "Sorry, I won't let you use password auth unencrypted.\n"); } else if (!finished && ses.authstate.authtypes & AUTH_TYPE_PASSWORD) { cli_auth_password(); finished = 1; cli_ses.lastauthtype = AUTH_TYPE_PASSWORD; } #endif TRACE(("cli_auth_try lastauthtype %d", cli_ses.lastauthtype)) if (!finished) { dropbear_exit("No auth methods could be used."); } TRACE(("leave cli_auth_try")) } /* A helper for getpass() that exits if the user cancels. The returned * password is statically allocated by getpass() */ char* getpass_or_cancel(char* prompt) { char* password = NULL; #ifdef DROPBEAR_PASSWORD_ENV /* Password provided in an environment var */ password = getenv(DROPBEAR_PASSWORD_ENV); if (password) { return password; } #endif password = getpass(prompt); /* 0x03 is a ctrl-c character in the buffer. */ if (password == NULL || strchr(password, '\3') != NULL) { dropbear_close("Interrupted."); } return password; }