freebsd-skq/lib/libgssapi/gss_encapsulate_token.c
pfg 378b205caf libgssapi: avoid NULL pointer dereferences.
While here also use NULL instead of zero for pointers.

Found with coccinelle.

MFC after:	1 week
2016-04-13 21:08:02 +00:00

132 lines
3.2 KiB
C

/*-
* Copyright (c) 2008 Doug Rabson
* 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.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
*
* $FreeBSD$
*/
#include <gssapi/gssapi.h>
#include <stdlib.h>
#include <string.h>
#include "utils.h"
OM_uint32
gss_encapsulate_token(const gss_buffer_t input_token, gss_OID oid,
gss_buffer_t output_token)
{
unsigned char *p;
size_t len, inside_len;
size_t a, b;
int i;
_gss_buffer_zero(output_token);
/*
* First time around, we calculate the size, second time, we
* encode the token.
*/
p = NULL;
for (i = 0; i < 2; i++) {
len = 0;
/*
* Token starts with [APPLICATION 0] SEQUENCE.
*/
if (p)
*p++ = 0x60;
len++;
/*
* The length embedded in the token is the space
* needed for the encapsulated oid plus the length of
* the inner token.
*/
if (oid->length > 127)
return (GSS_S_DEFECTIVE_TOKEN);
inside_len = 2 + oid->length + input_token->length;
/*
* Figure out how to encode the length
*/
if (inside_len < 128) {
if (p)
*p++ = inside_len;
len++;
} else {
b = 1;
if (inside_len >= 0x100)
b++;
if (inside_len >= 0x10000)
b++;
if (inside_len >= 0x1000000)
b++;
if (p)
*p++ = b | 0x80;
len++;
a = inside_len << 8*(4 - b);
while (b) {
if (p)
*p++ = (a >> 24);
a <<= 8;
len++;
b--;
}
}
/*
* Encode the OID for the mechanism. Simplify life by
* assuming that the OID length is less than 128 bytes.
*/
if (p)
*p++ = 0x06;
len++;
if (p)
*p++ = oid->length;
len++;
if (p) {
memcpy(p, oid->elements, oid->length);
p += oid->length;
}
len += oid->length;
if (p) {
memcpy(p, input_token->value, input_token->length);
p += input_token->length;
}
len += input_token->length;
if (i == 0) {
output_token->length = len;
output_token->value = malloc(len);
if (!output_token->value)
return (GSS_S_DEFECTIVE_TOKEN);
p = output_token->value;
}
}
return (GSS_S_COMPLETE);
}