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/*
* Copyright (C) 1999-2001,2005,2009 Brendan Cully <brendan@kublai.com>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*/
/* GSS login/authentication code
*
* An overview of the authentication method is in RFC 1731.
*
* An overview of the C API used is in RFC 2744.
* Of note is section 3.2, which describes gss_buffer_desc.
* The length should not include a terminating '\0' byte, and the client
* should not expect the value field to be '\0'terminated.
*/
#if HAVE_CONFIG_H
# include "config.h"
#endif
#include "mutt.h"
#include "imap_private.h"
#include "auth.h"
#include <netinet/in.h>
#ifdef HAVE_HEIMDAL
# include <gssapi/gssapi.h>
# define gss_nt_service_name GSS_C_NT_HOSTBASED_SERVICE
#else
# include <gssapi/gssapi.h>
# include <gssapi/gssapi_generic.h>
#endif
#define GSS_BUFSIZE 8192
#define GSS_AUTH_P_NONE 1
#define GSS_AUTH_P_INTEGRITY 2
#define GSS_AUTH_P_PRIVACY 4
static void print_gss_error(OM_uint32 err_maj, OM_uint32 err_min)
{
OM_uint32 maj_stat, min_stat;
OM_uint32 msg_ctx = 0;
gss_buffer_desc status_string;
char buf_maj[512];
char buf_min[512];
size_t status_len;
do
{
maj_stat = gss_display_status (&min_stat,
err_maj,
GSS_C_GSS_CODE,
GSS_C_NO_OID,
&msg_ctx,
&status_string);
if (GSS_ERROR(maj_stat))
break;
status_len = status_string.length;
if (status_len >= sizeof(buf_maj))
status_len = sizeof(buf_maj) - 1;
strncpy(buf_maj, (char*) status_string.value, status_len);
buf_maj[status_len] = '\0';
gss_release_buffer(&min_stat, &status_string);
maj_stat = gss_display_status (&min_stat,
err_min,
GSS_C_MECH_CODE,
GSS_C_NULL_OID,
&msg_ctx,
&status_string);
if (!GSS_ERROR(maj_stat))
{
status_len = status_string.length;
if (status_len >= sizeof(buf_min))
status_len = sizeof(buf_min) - 1;
strncpy(buf_min, (char*) status_string.value, status_len);
buf_min[status_len] = '\0';
gss_release_buffer(&min_stat, &status_string);
}
} while (!GSS_ERROR(maj_stat) && msg_ctx != 0);
dprint (2, (debugfile, "((%s:%d )(%s:%d))", buf_maj, err_maj, buf_min, err_min));
}
/* imap_auth_gss: AUTH=GSSAPI support. */
imap_auth_res_t imap_auth_gss (IMAP_DATA* idata, const char* method)
{
gss_buffer_desc request_buf, send_token;
gss_buffer_t sec_token;
gss_name_t target_name;
gss_ctx_id_t context;
#ifdef DEBUG
gss_OID mech_name;
char server_conf_flags;
#endif
gss_qop_t quality;
int cflags;
OM_uint32 maj_stat, min_stat;
char buf1[GSS_BUFSIZE], buf2[GSS_BUFSIZE];
unsigned long buf_size;
int rc;
if (!mutt_bit_isset (idata->capabilities, AGSSAPI))
return IMAP_AUTH_UNAVAIL;
if (mutt_account_getuser (&idata->conn->account))
return IMAP_AUTH_FAILURE;
/* get an IMAP service ticket for the server */
snprintf (buf1, sizeof (buf1), "imap@%s", idata->conn->account.host);
request_buf.value = buf1;
request_buf.length = strlen (buf1);
maj_stat = gss_import_name (&min_stat, &request_buf, gss_nt_service_name,
&target_name);
if (maj_stat != GSS_S_COMPLETE)
{
dprint (2, (debugfile, "Couldn't get service name for [%s]\n", buf1));
return IMAP_AUTH_UNAVAIL;
}
#ifdef DEBUG
else if (debuglevel >= 2)
{
maj_stat = gss_display_name (&min_stat, target_name, &request_buf,
&mech_name);
dprint (2, (debugfile, "Using service name [%s]\n",
(char*) request_buf.value));
maj_stat = gss_release_buffer (&min_stat, &request_buf);
}
#endif
/* Acquire initial credentials - without a TGT GSSAPI is UNAVAIL */
sec_token = GSS_C_NO_BUFFER;
context = GSS_C_NO_CONTEXT;
/* build token */
maj_stat = gss_init_sec_context (&min_stat, GSS_C_NO_CREDENTIAL, &context,
target_name, GSS_C_NO_OID, GSS_C_MUTUAL_FLAG | GSS_C_SEQUENCE_FLAG, 0,
GSS_C_NO_CHANNEL_BINDINGS, sec_token, NULL, &send_token,
(unsigned int*) &cflags, NULL);
if (maj_stat != GSS_S_COMPLETE && maj_stat != GSS_S_CONTINUE_NEEDED)
{
print_gss_error(maj_stat, min_stat);
dprint (1, (debugfile, "Error acquiring credentials - no TGT?\n"));
gss_release_name (&min_stat, &target_name);
return IMAP_AUTH_UNAVAIL;
}
/* now begin login */
mutt_message _("Authenticating (GSSAPI)...");
imap_cmd_start (idata, "AUTHENTICATE GSSAPI");
/* expect a null continuation response ("+") */
do
rc = imap_cmd_step (idata);
while (rc == IMAP_CMD_CONTINUE);
if (rc != IMAP_CMD_RESPOND)
{
dprint (2, (debugfile, "Invalid response from server: %s\n", buf1));
gss_release_name (&min_stat, &target_name);
goto bail;
}
/* now start the security context initialisation loop... */
dprint (2, (debugfile, "Sending credentials\n"));
mutt_to_base64 ((unsigned char*) buf1, send_token.value, send_token.length,
sizeof (buf1) - 2);
gss_release_buffer (&min_stat, &send_token);
safe_strcat (buf1, sizeof (buf1), "\r\n");
mutt_socket_write (idata->conn, buf1);
while (maj_stat == GSS_S_CONTINUE_NEEDED)
{
/* Read server data */
do
rc = imap_cmd_step (idata);
while (rc == IMAP_CMD_CONTINUE);
if (rc != IMAP_CMD_RESPOND)
{
dprint (1, (debugfile, "Error receiving server response.\n"));
gss_release_name (&min_stat, &target_name);
goto bail;
}
request_buf.length = mutt_from_base64 (buf2, idata->buf + 2);
request_buf.value = buf2;
sec_token = &request_buf;
/* Write client data */
maj_stat = gss_init_sec_context (&min_stat, GSS_C_NO_CREDENTIAL, &context,
target_name, GSS_C_NO_OID, GSS_C_MUTUAL_FLAG | GSS_C_SEQUENCE_FLAG, 0,
GSS_C_NO_CHANNEL_BINDINGS, sec_token, NULL, &send_token,
(unsigned int*) &cflags, NULL);
if (maj_stat != GSS_S_COMPLETE && maj_stat != GSS_S_CONTINUE_NEEDED)
{
print_gss_error(maj_stat, min_stat);
dprint (1, (debugfile, "Error exchanging credentials\n"));
gss_release_name (&min_stat, &target_name);
goto err_abort_cmd;
}
mutt_to_base64 ((unsigned char*) buf1, send_token.value,
send_token.length, sizeof (buf1) - 2);
gss_release_buffer (&min_stat, &send_token);
safe_strcat (buf1, sizeof (buf1), "\r\n");
mutt_socket_write (idata->conn, buf1);
}
gss_release_name (&min_stat, &target_name);
/* get security flags and buffer size */
do
rc = imap_cmd_step (idata);
while (rc == IMAP_CMD_CONTINUE);
if (rc != IMAP_CMD_RESPOND)
{
dprint (1, (debugfile, "Error receiving server response.\n"));
goto bail;
}
request_buf.length = mutt_from_base64 (buf2, idata->buf + 2);
request_buf.value = buf2;
maj_stat = gss_unwrap (&min_stat, context, &request_buf, &send_token,
&cflags, &quality);
if (maj_stat != GSS_S_COMPLETE)
{
print_gss_error(maj_stat, min_stat);
dprint (2, (debugfile, "Couldn't unwrap security level data\n"));
gss_release_buffer (&min_stat, &send_token);
goto err_abort_cmd;
}
dprint (2, (debugfile, "Credential exchange complete\n"));
/* first octet is security levels supported. We want NONE */
#ifdef DEBUG
server_conf_flags = ((char*) send_token.value)[0];
#endif
if ( !(((char*) send_token.value)[0] & GSS_AUTH_P_NONE)
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