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/*
* Copyright (c) 1997 - 2001 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 "gsskrb5_locl.h"
/*
* return the length of the mechanism in token or -1
* (which implies that the token was bad - GSS_S_DEFECTIVE_TOKEN
*/
ssize_t
_gsskrb5_get_mech (const u_char *ptr,
size_t total_len,
const u_char **mech_ret)
{
size_t len, len_len, mech_len, foo;
const u_char *p = ptr;
int e;
if (total_len < 1)
return -1;
if (*p++ != 0x60)
return -1;
e = der_get_length (p, total_len - 1, &len, &len_len);
if (e || 1 + len_len + len != total_len)
return -1;
if (total_len < 1 + len_len + 1)
return -1;
p += len_len;
if (*p++ != 0x06)
return -1;
e = der_get_length (p, total_len - 1 - len_len - 1,
&mech_len, &foo);
if (e)
return -1;
p += foo;
*mech_ret = p;
return mech_len;
}
OM_uint32
_gssapi_verify_mech_header(u_char **str,
size_t total_len,
gss_OID mech)
{
const u_char *p;
ssize_t mech_len;
mech_len = _gsskrb5_get_mech (*str, total_len, &p);
if (mech_len < 0)
return GSS_S_DEFECTIVE_TOKEN;
if (mech_len != mech->length)
return GSS_S_BAD_MECH;
if (mech_len > total_len)
return GSS_S_BAD_MECH;
if (p - *str > total_len - mech_len)
return GSS_S_BAD_MECH;
if (ct_memcmp(p,
mech->elements,
mech->length) != 0)
return GSS_S_BAD_MECH;
p += mech_len;
*str = rk_UNCONST(p);
return GSS_S_COMPLETE;
}
OM_uint32
_gsskrb5_verify_header(u_char **str,
size_t total_len,
const void *type,
gss_OID oid)
{
OM_uint32 ret;
size_t len;
u_char *p = *str;
ret = _gssapi_verify_mech_header(str, total_len, oid);
if (ret)
return ret;
len = total_len - (*str - p);
if (len < 2)
return GSS_S_DEFECTIVE_TOKEN;
if (ct_memcmp (*str, type, 2) != 0)
return GSS_S_DEFECTIVE_TOKEN;
*str += 2;
return 0;
}
/*
* Remove the GSS-API wrapping from `in_token' giving `out_data.
* Does not copy data, so just free `in_token'.
*/
OM_uint32
_gssapi_decapsulate(
OM_uint32 *minor_status,
gss_buffer_t input_token_buffer,
krb5_data *out_data,
const gss_OID mech
)
{
u_char *p;
OM_uint32 ret;
p = input_token_buffer->value;
ret = _gssapi_verify_mech_header(&p,
input_token_buffer->length,
mech);
if (ret) {
*minor_status = 0;
return ret;
}
out_data->length = input_token_buffer->length -
(p - (u_char *)input_token_buffer->value);
out_data->data = p;
return GSS_S_COMPLETE;
}
/*
* Remove the GSS-API wrapping from `in_token' giving `out_data.
* Does not copy data, so just free `in_token'.
*/
OM_uint32
_gsskrb5_decapsulate(OM_uint32 *minor_status,
gss_buffer_t input_token_buffer,
krb5_data *out_data,
const void *type,
gss_OID oid)
{
u_char *p;
OM_uint32 ret;
p = input_token_buffer->value;
ret = _gsskrb5_verify_header(&p,
input_token_buffer->length,
type,
oid);
if (ret) {
*minor_status = 0;
return ret;
}
out_data->length = input_token_buffer->length -
(p - (u_char *)input_token_buffer->value);
out_data->data = p;
return GSS_S_COMPLETE;
}
/*
* Verify padding of a gss wrapped message and return its length.
*/
OM_uint32
_gssapi_verify_pad(gss_buffer_t wrapped_token,
size_t datalen,
size_t *padlen)
{
u_char *pad;
size_t padlength;
int i;
if (wrapped_token->length < 1)
return GSS_S_BAD_MECH;
pad = (u_char *)wrapped_token->value + wrapped_token->length;
padlength = pad[-1];
if (padlength > datalen)
return GSS_S_BAD_MECH;
for (i = padlength; i > 0 && *--pad == padlength; i--)
;
if (i != 0)
return GSS_S_BAD_MIC;
*padlen = padlength;
return 0;
}
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