OpenBSD-4.6/kerberosV/src/appl/popper/auth_gssapi.c
/*
* Copyright (c) 2004 Kungliga Tekniska Högskolan
* (Royal Institute of Technology, Stockholm, Sweden).
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* 3. Neither the name of the Institute nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <popper.h>
#include <base64.h>
#include <pop_auth.h>
RCSID("$KTH: auth_gssapi.c,v 1.2 2004/06/15 11:24:21 joda Exp $");
#if defined(SASL) && defined(KRB5)
#include <gssapi.h>
extern krb5_context gssapi_krb5_context;
struct gss_state {
gss_ctx_id_t context_hdl;
gss_OID mech_oid;
gss_name_t client_name;
int stage;
};
static void
gss_set_error (struct gss_state *gs, int min_stat)
{
OM_uint32 new_stat;
OM_uint32 msg_ctx = 0;
gss_buffer_desc status_string;
OM_uint32 ret;
do {
ret = gss_display_status (&new_stat,
min_stat,
GSS_C_MECH_CODE,
gs->mech_oid,
&msg_ctx,
&status_string);
pop_auth_set_error(status_string.value);
gss_release_buffer (&new_stat, &status_string);
} while (!GSS_ERROR(ret) && msg_ctx != 0);
}
static int
gss_loop(POP *p, void *state,
/* const */ void *input, size_t input_length,
void **output, size_t *output_length)
{
struct gss_state *gs = state;
gss_buffer_desc real_input_token, real_output_token;
gss_buffer_t input_token = &real_input_token,
output_token = &real_output_token;
OM_uint32 maj_stat, min_stat;
gss_channel_bindings_t bindings = GSS_C_NO_CHANNEL_BINDINGS;
if(gs->stage == 0) {
/* we require an initial response, so ask for one if not
present */
gs->stage++;
if(input == NULL && input_length == 0) {
/* XXX this could be done better */
fputs("+ \r\n", p->output);
fflush(p->output);
return POP_AUTH_CONTINUE;
}
}
if(gs->stage == 1) {
input_token->value = input;
input_token->length = input_length;
maj_stat =
gss_accept_sec_context (&min_stat,
&gs->context_hdl,
GSS_C_NO_CREDENTIAL,
input_token,
bindings,
&gs->client_name,
&gs->mech_oid,
output_token,
NULL,
NULL,
NULL);
if (GSS_ERROR(maj_stat)) {
gss_set_error(gs, min_stat);
return POP_AUTH_FAILURE;
}
if (output_token->length != 0) {
*output = output_token->value;
*output_length = output_token->length;
}
if(maj_stat == GSS_S_COMPLETE)
gs->stage++;
return POP_AUTH_CONTINUE;
}
if(gs->stage == 2) {
/* send wanted protection levels */
unsigned char x[4] = { 1, 0, 0, 0 };
input_token->value = x;
input_token->length = 4;
maj_stat = gss_wrap(&min_stat,
gs->context_hdl,
FALSE,
GSS_C_QOP_DEFAULT,
input_token,
NULL,
output_token);
if (GSS_ERROR(maj_stat)) {
gss_set_error(gs, min_stat);
return POP_AUTH_FAILURE;
}
*output = output_token->value;
*output_length = output_token->length;
gs->stage++;
return POP_AUTH_CONTINUE;
}
if(gs->stage == 3) {
/* receive protection levels and username */
char *name;
krb5_principal principal;
gss_buffer_desc export_name;
gss_OID oid;
unsigned char *ptr;
input_token->value = input;
input_token->length = input_length;
maj_stat = gss_unwrap (&min_stat,
gs->context_hdl,
input_token,
output_token,
NULL,
NULL);
if (GSS_ERROR(maj_stat)) {
gss_set_error(gs, min_stat);
return POP_AUTH_FAILURE;
}
if(output_token->length < 5) {
pop_auth_set_error("response too short");
return POP_AUTH_FAILURE;
}
ptr = output_token->value;
if(ptr[0] != 1) {
pop_auth_set_error("must use clear text");
return POP_AUTH_FAILURE;
}
memmove(output_token->value, ptr + 4, output_token->length - 4);
ptr[output_token->length - 4] = '\0';
maj_stat = gss_display_name(&min_stat, gs->client_name,
&export_name, &oid);
if(maj_stat != GSS_S_COMPLETE) {
gss_set_error(gs, min_stat);
return POP_AUTH_FAILURE;
}
/* XXX kerberos */
if(oid != GSS_KRB5_NT_PRINCIPAL_NAME) {
pop_auth_set_error("unexpected gss name type");
gss_release_buffer(&min_stat, &export_name);
return POP_AUTH_FAILURE;
}
name = malloc(export_name.length + 1);
if(name == NULL) {
pop_auth_set_error("out of memory");
gss_release_buffer(&min_stat, &export_name);
return POP_AUTH_FAILURE;
}
memcpy(name, export_name.value, export_name.length);
name[export_name.length] = '\0';
gss_release_buffer(&min_stat, &export_name);
krb5_parse_name(gssapi_krb5_context, name, &principal);
if(!krb5_kuserok(gssapi_krb5_context, principal, ptr)) {
pop_auth_set_error("Permission denied");
return POP_AUTH_FAILURE;
}
strlcpy(p->user, ptr, sizeof(p->user));
return POP_AUTH_COMPLETE;
}
return POP_AUTH_FAILURE;
}
static int
gss_init(POP *p, void **state)
{
struct gss_state *gs = malloc(sizeof(*gs));
if(gs == NULL) {
pop_auth_set_error("out of memory");
return POP_AUTH_FAILURE;
}
gs->context_hdl = GSS_C_NO_CONTEXT;
gs->stage = 0;
*state = gs;
return POP_AUTH_CONTINUE;
}
static int
gss_cleanup(POP *p, void *state)
{
OM_uint32 min_stat;
struct gss_state *gs = state;
if(gs->context_hdl != GSS_C_NO_CONTEXT)
gss_delete_sec_context(&min_stat, &gs->context_hdl, GSS_C_NO_BUFFER);
free(state);
return POP_AUTH_CONTINUE;
}
struct auth_mech gssapi_mech = {
"GSSAPI", gss_init, gss_loop, gss_cleanup
};
#endif /* KRB5 */