Mercurial > dropbear
view svr-authpam.c @ 1306:34e6127ef02e
merge fixes from PuTTY import.c
toint() from misc.c
(revids are from hggit conversion)
changeset: 4620:60a336a6c85c
user: Simon Tatham <[email protected]>
date: Thu Feb 25 20:26:33 2016 +0000
files: import.c
description:
Fix potential segfaults in reading OpenSSH's ASN.1 key format.
The length coming back from ber_read_id_len might have overflowed, so
treat it as potentially negative. Also, while I'm here, accumulate it
inside ber_read_id_len as an unsigned, so as to avoid undefined
behaviour on integer overflow, and toint() it before return.
Thanks to Hanno Böck for spotting this, with the aid of AFL.
(cherry picked from commit 5b7833cd474a24ec098654dcba8cb9509f3bf2c1)
Conflicts:
import.c
(cherry-picker's note: resolving the conflict involved removing an
entire section of the original commit which fixed ECDSA code not
present on this branch)
changeset: 4619:9c6c638d98d8
user: Simon Tatham <[email protected]>
date: Sun Jul 14 10:45:54 2013 +0000
files: import.c ssh.c sshdss.c sshpubk.c sshrsa.c
description:
Tighten up a lot of casts from unsigned to int which are read by one
of the GET_32BIT macros and then used as length fields. Missing bounds
checks against zero have been added, and also I've introduced a helper
function toint() which casts from unsigned to int in such a way as to
avoid C undefined behaviour, since I'm not sure I trust compilers any
more to do the obviously sensible thing.
[originally from svn r9918]
changeset: 4618:3957829f24d3
user: Simon Tatham <[email protected]>
date: Mon Jul 08 22:36:04 2013 +0000
files: import.c sshdss.c sshrsa.c
description:
Add an assortment of extra safety checks.
[originally from svn r9896]
changeset: 4617:2cddee0bce12
user: Jacob Nevins <[email protected]>
date: Wed Dec 07 00:24:45 2005 +0000
files: import.c
description:
Institutional failure to memset() things pointed at rather than pointers.
Things should now be zeroed and memory not leaked. Spotted by Brant Thomsen.
[originally from svn r6476]
changeset: 4616:24ac78a9c71d
user: Simon Tatham <[email protected]>
date: Wed Feb 11 13:58:27 2004 +0000
files: import.c
description:
Jacob's last-minute testing found a couple of trivial bugs in
import.c, and my attempts to reproduce them in cmdgen found another
one there :-)
[originally from svn r3847]
changeset: 4615:088d39a73db0
user: Simon Tatham <[email protected]>
date: Thu Jan 22 18:52:49 2004 +0000
files: import.c
description:
Placate some gcc warnings.
[originally from svn r3761]
changeset: 4614:e4288bad4d93
parent: 1758:108b8924593d
user: Simon Tatham <[email protected]>
date: Fri Oct 03 21:21:23 2003 +0000
files: import.c
description:
My ASN.1 decoder returned wrong IDs for anything above 0x1E! Good
job it's never had to yet. Ahem.
[originally from svn r3479]
author | Matt Johnston <matt@ucc.asn.au> |
---|---|
date | Tue, 12 Jul 2016 23:00:01 +0800 |
parents | c59c10803afd |
children | 750ec4ec4cbe |
line wrap: on
line source
/* * Dropbear SSH * * Copyright (c) 2004 Martin Carlsson * Portions (c) 2004 Matt Johnston * 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. */ /* Validates a user password using PAM */ #include "includes.h" #include "session.h" #include "buffer.h" #include "dbutil.h" #include "auth.h" #ifdef ENABLE_SVR_PAM_AUTH #if defined(HAVE_SECURITY_PAM_APPL_H) #include <security/pam_appl.h> #elif defined (HAVE_PAM_PAM_APPL_H) #include <pam/pam_appl.h> #endif struct UserDataS { char* user; char* passwd; }; /* PAM conversation function - for now we only handle one message */ int pamConvFunc(int num_msg, const struct pam_message **msg, struct pam_response **respp, void *appdata_ptr) { int rc = PAM_SUCCESS; struct pam_response* resp = NULL; struct UserDataS* userDatap = (struct UserDataS*) appdata_ptr; unsigned int msg_len = 0; unsigned int i = 0; char * compare_message = NULL; TRACE(("enter pamConvFunc")) if (num_msg != 1) { /* If you're getting here - Dropbear probably can't support your pam * modules. This whole file is a bit of a hack around lack of * asynchronocity in PAM anyway. */ dropbear_log(LOG_INFO, "pamConvFunc() called with >1 messages: not supported."); return PAM_CONV_ERR; } /* make a copy we can strip */ compare_message = m_strdup((*msg)->msg); /* Make the string lowercase. */ msg_len = strlen(compare_message); for (i = 0; i < msg_len; i++) { compare_message[i] = tolower(compare_message[i]); } /* If the string ends with ": ", remove the space. ie "login: " vs "login:" */ if (msg_len > 2 && compare_message[msg_len-2] == ':' && compare_message[msg_len-1] == ' ') { compare_message[msg_len-1] = '\0'; } switch((*msg)->msg_style) { case PAM_PROMPT_ECHO_OFF: if (!(strcmp(compare_message, "password:") == 0)) { /* We don't recognise the prompt as asking for a password, so can't handle it. Add more above as required for different pam modules/implementations. If you need to add an entry here please mail the Dropbear developer */ dropbear_log(LOG_NOTICE, "PAM unknown prompt '%s' (no echo)", compare_message); rc = PAM_CONV_ERR; break; } /* You have to read the PAM module-writers' docs (do we look like * module writers? no.) to find out that the module will * free the pam_response and its resp element - ie we _must_ malloc * it here */ resp = (struct pam_response*) m_malloc(sizeof(struct pam_response)); memset(resp, 0, sizeof(struct pam_response)); resp->resp = m_strdup(userDatap->passwd); m_burn(userDatap->passwd, strlen(userDatap->passwd)); (*respp) = resp; break; case PAM_PROMPT_ECHO_ON: if (!( (strcmp(compare_message, "login:" ) == 0) || (strcmp(compare_message, "please enter username:") == 0) || (strcmp(compare_message, "username:") == 0) )) { /* We don't recognise the prompt as asking for a username, so can't handle it. Add more above as required for different pam modules/implementations. If you need to add an entry here please mail the Dropbear developer */ dropbear_log(LOG_NOTICE, "PAM unknown prompt '%s' (with echo)", compare_message); rc = PAM_CONV_ERR; break; } /* You have to read the PAM module-writers' docs (do we look like * module writers? no.) to find out that the module will * free the pam_response and its resp element - ie we _must_ malloc * it here */ resp = (struct pam_response*) m_malloc(sizeof(struct pam_response)); memset(resp, 0, sizeof(struct pam_response)); resp->resp = m_strdup(userDatap->user); TRACE(("userDatap->user='%s'", userDatap->user)) (*respp) = resp; break; case PAM_ERROR_MSG: case PAM_TEXT_INFO: if (msg_len > 0) { buffer * pam_err = buf_new(msg_len + 4); buf_setpos(pam_err, 0); buf_putbytes(pam_err, "\r\n", 2); buf_putbytes(pam_err, (*msg)->msg, msg_len); buf_putbytes(pam_err, "\r\n", 2); buf_setpos(pam_err, 0); send_msg_userauth_banner(pam_err); buf_free(pam_err); } break; default: TRACE(("Unknown message type")) rc = PAM_CONV_ERR; break; } m_free(compare_message); TRACE(("leave pamConvFunc, rc %d", rc)) return rc; } /* Process a password auth request, sending success or failure messages as * appropriate. To the client it looks like it's doing normal password auth (as * opposed to keyboard-interactive or something), so the pam module has to be * fairly standard (ie just "what's your username, what's your password, OK"). * * Keyboard interactive would be a lot nicer, but since PAM is synchronous, it * gets very messy trying to send the interactive challenges, and read the * interactive responses, over the network. */ void svr_auth_pam() { struct UserDataS userData = {NULL, NULL}; struct pam_conv pamConv = { pamConvFunc, &userData /* submitted to pamvConvFunc as appdata_ptr */ }; pam_handle_t* pamHandlep = NULL; char * password = NULL; unsigned int passwordlen; int rc = PAM_SUCCESS; unsigned char changepw; /* check if client wants to change password */ changepw = buf_getbool(ses.payload); if (changepw) { /* not implemented by this server */ send_msg_userauth_failure(0, 1); goto cleanup; } password = buf_getstring(ses.payload, &passwordlen); /* used to pass data to the PAM conversation function - don't bother with * strdup() etc since these are touched only by our own conversation * function (above) which takes care of it */ userData.user = ses.authstate.pw_name; userData.passwd = password; /* Init pam */ if ((rc = pam_start("sshd", NULL, &pamConv, &pamHandlep)) != PAM_SUCCESS) { dropbear_log(LOG_WARNING, "pam_start() failed, rc=%d, %s", rc, pam_strerror(pamHandlep, rc)); goto cleanup; } /* just to set it to something */ if ((rc = pam_set_item(pamHandlep, PAM_TTY, "ssh")) != PAM_SUCCESS) { dropbear_log(LOG_WARNING, "pam_set_item() failed, rc=%d, %s", rc, pam_strerror(pamHandlep, rc)); goto cleanup; } #ifdef HAVE_PAM_FAIL_DELAY /* We have our own random delay code already, disable PAM's */ (void) pam_fail_delay(pamHandlep, 0 /* musec_delay */); #endif /* (void) pam_set_item(pamHandlep, PAM_FAIL_DELAY, (void*) pamDelayFunc); */ if ((rc = pam_authenticate(pamHandlep, 0)) != PAM_SUCCESS) { dropbear_log(LOG_WARNING, "pam_authenticate() failed, rc=%d, %s", rc, pam_strerror(pamHandlep, rc)); dropbear_log(LOG_WARNING, "Bad PAM password attempt for '%s' from %s", ses.authstate.pw_name, svr_ses.addrstring); send_msg_userauth_failure(0, 1); goto cleanup; } if ((rc = pam_acct_mgmt(pamHandlep, 0)) != PAM_SUCCESS) { dropbear_log(LOG_WARNING, "pam_acct_mgmt() failed, rc=%d, %s", rc, pam_strerror(pamHandlep, rc)); dropbear_log(LOG_WARNING, "Bad PAM password attempt for '%s' from %s", ses.authstate.pw_name, svr_ses.addrstring); send_msg_userauth_failure(0, 1); goto cleanup; } /* successful authentication */ dropbear_log(LOG_NOTICE, "PAM password auth succeeded for '%s' from %s", ses.authstate.pw_name, svr_ses.addrstring); send_msg_userauth_success(); cleanup: if (password != NULL) { m_burn(password, passwordlen); m_free(password); } if (pamHandlep != NULL) { TRACE(("pam_end")) (void) pam_end(pamHandlep, 0 /* pam_status */); } } #endif /* ENABLE_SVR_PAM_AUTH */