/* md2.c - MD2 Message-Digest Algorithm
* Copyright (C) 2002,2003 MontaVista Software.
* Corey Minyard <cminyard@mvista.com>
*
* This file is part of the IPMI Interface (IPMIIF).
*
* This is the MD2 algorithm, as defined by RFC1319.
*
* This software is available to you under a choice of one of two
* licenses. You may choose to be licensed under the terms of the GNU
* Lesser General Public License (GPL) Version 2 or the modified BSD
* license below. The following disclamer applies to both licenses:
*
* THIS SOFTWARE IS PROVIDED ``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 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.
*
* GNU Lesser General Public Licence
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public License
* as published by the Free Software Foundation; either version 2 of
* the License, or (at your option) any later version.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this program; if not, write to the Free
* Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*
* Modified BSD Licence
*
* 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. The name of the author may not be used to endorse or promote
* products derived from this software without specific prior
* written permission.
*/
#include <stdlib.h>
#include <stdint.h>
#include <string.h>
#include <errno.h>
#include <OpenIPMI/internal/md2.h>
typedef uint32_t u32;
typedef uint8_t byte;
typedef struct {
byte buf[48];
byte inbuf[16];
byte checksum[16];
int count;
byte l;
} MD2_CONTEXT;
static void
md2_init( MD2_CONTEXT *ctx )
{
memset(ctx->buf, 0, 16);
memset(ctx->checksum, 0, 16);
ctx->count = 0;
ctx->l = 0;
}
/* The "Bytes of PI" defined by the algorithm. */
static byte s[256] =
{
41, 46, 67, 201, 162, 216, 124, 1, 61, 54, 84, 161, 236, 240, 6, 19,
98, 167, 5, 243, 192, 199, 115, 140, 152, 147, 43, 217, 188, 76, 130, 202,
30, 155, 87, 60, 253, 212, 224, 22, 103, 66, 111, 24, 138, 23, 229, 18,
190, 78, 196, 214, 218, 158, 222, 73, 160, 251, 245, 142, 187, 47, 238, 122,
169, 104, 121, 145, 21, 178, 7, 63, 148, 194, 16, 137, 11, 34, 95, 33,
128, 127, 93, 154, 90, 144, 50, 39, 53, 62, 204, 231, 191, 247, 151, 3,
255, 25, 48, 179, 72, 165, 181, 209, 215, 94, 146, 42, 172, 86, 170, 198,
79, 184, 56, 210, 150, 164, 125, 182, 118, 252, 107, 226, 156, 116, 4, 241,
69, 157, 112, 89, 100, 113, 135, 32, 134, 91, 207, 101, 230, 45, 168, 2,
27, 96, 37, 173, 174, 176, 185, 246, 28, 70, 97, 105, 52, 64, 126, 15,
85, 71, 163, 35, 221, 81, 175, 58, 195, 92, 249, 206, 186, 197, 234, 38,
44, 83, 13, 110, 133, 40, 132, 9, 211, 223, 205, 244, 65, 129, 77, 82,
106, 220, 55, 200, 108, 193, 171, 250, 36, 225, 123, 8, 12, 189, 177, 74,
120, 136, 149, 139, 227, 99, 232, 109, 233, 203, 213, 254, 59, 0, 29, 57,
242, 239, 183, 14, 102, 88, 208, 228, 166, 119, 114, 248, 235, 117, 75, 10,
49, 68, 80, 180, 143, 237, 31, 26, 219, 153, 141, 51, 159, 17, 131, 20
};
static void
checksum( MD2_CONTEXT *ctx )
{
int j;
for (j=0; j<16; j++) {
ctx->checksum[j] ^= s[ctx->inbuf[j] ^ ctx->l];
ctx->l = ctx->checksum[j];
}
}
/****************
* transform 16 bytes
*/
static void
transform( MD2_CONTEXT *ctx )
{
int j, k;
int t;
for (j=0; j<16; j++) {
ctx->buf[j+16] = ctx->inbuf[j];
ctx->buf[j+32] = ctx->inbuf[j] ^ ctx->buf[j];
}
t = 0;
for (j=0; j<18; j++) {
for (k=0; k<48; k++) {
t = ctx->buf[k] ^ s[t];
ctx->buf[k] = t;
}
t = (t + j) % 256;
}
}
/* The routine updates the message-digest context to
* account for the presence of each of the characters inBuf[0..inLen-1]
* in the message whose digest is being computed.
*/
static void
md2_write( MD2_CONTEXT *ctx, byte *inbuf, size_t inlen )
{
int cnt;
if( !inbuf )
return;
if (ctx->count+inlen > 16)
cnt = 16-ctx->count;
else
cnt = inlen;
memcpy(ctx->inbuf+ctx->count, inbuf, cnt);
inbuf += cnt;
inlen -= cnt;
ctx->count += cnt;
while (ctx->count == 16) {
checksum(ctx);
transform(ctx);
if (inlen > 16)
cnt = 16;
else
cnt = inlen;
memcpy(ctx->inbuf, inbuf, cnt);
inbuf += cnt;
inlen -= cnt;
ctx->count = cnt;
}
}
/* The routine final terminates the message-digest computation and
* ends with the desired message digest in mdContext->digest[0...15].
* The handle is prepared for a new MD2 cycle.
* Returns 16 bytes representing the digest.
*/
static void
md2_final( MD2_CONTEXT *ctx )
{
int i, cnt;
cnt = 16 - ctx->count;
for (i=ctx->count; i<16; i++)
ctx->inbuf[i] = cnt;
checksum(ctx);
transform(ctx);
memcpy(ctx->inbuf, ctx->checksum, 16);
transform(ctx);
}
static byte *
md2_read( MD2_CONTEXT *hd )
{
return hd->buf;
}
struct ipmi_authdata_s
{
void *info;
void *(*mem_alloc)(void *info, int size);
void (*mem_free)(void *info, void *data);
unsigned char data[16];
};
/* External functions for the IPMI authcode algorithms. */
int
ipmi_md2_authcode_init(unsigned char *password,
ipmi_authdata_t *handle,
void *info,
void *(*mem_alloc)(void *info, int size),
void (*mem_free)(void *info, void *data))
{
struct ipmi_authdata_s *data;
data = mem_alloc(info, sizeof(*data));
if (!data)
return ENOMEM;
data->info = info;
data->mem_alloc = mem_alloc;
data->mem_free = mem_free;
memcpy(data->data, password, 16);
*handle = data;
return 0;
}
int
ipmi_md2_authcode_gen(ipmi_authdata_t handle,
ipmi_auth_sg_t data[],
void *output)
{
MD2_CONTEXT ctx;
int i;
md2_init(&ctx);
md2_write(&ctx, handle->data, 16);
for (i=0; data[i].data != NULL; i++) {
md2_write(&ctx, data[i].data, data[i].len);
}
md2_write(&ctx, handle->data, 16);
md2_final(&ctx);
memcpy(output, md2_read(&ctx), 16);
return 0;
}
int
ipmi_md2_authcode_check(ipmi_authdata_t handle,
ipmi_auth_sg_t data[],
void *code)
{
MD2_CONTEXT ctx;
int i;
md2_init(&ctx);
md2_write(&ctx, handle->data, 16);
for (i=0; data[i].data != NULL; i++) {
md2_write(&ctx, data[i].data, data[i].len);
}
md2_write(&ctx, handle->data, 16);
md2_final(&ctx);
if (memcmp(code, md2_read(&ctx), 16) != 0)
return EINVAL;
return 0;
}
void
ipmi_md2_authcode_cleanup(ipmi_authdata_t handle)
{
memset(handle->data, 0, sizeof(handle->data));
handle->mem_free(handle->info, handle);
handle = NULL;
}
/* The stuff below is libgcrypt-specific, and does not apply to IPMI. The
stuff above is generic. Nice separation, thank you :-).
-Corey Minyard
*/
#if 0
/****************
* Return some information about the algorithm. We need algo here to
* distinguish different flavors of the algorithm.
* Returns: A pointer to string describing the algorithm or NULL if
* the ALGO is invalid.
*/
static const char *
md2_get_info( int algo, size_t *contextsize,
byte **r_asnoid, int *r_asnlen, int *r_mdlen,
void (**r_init)( void *c ),
void (**r_write)( void *c, byte *buf, size_t nbytes ),
void (**r_final)( void *c ),
byte *(**r_read)( void *c )
)
{
static byte asn[18] = /* Object ID is 1.2.840.113549.2.5 */
{ 0x30, 0x20, 0x30, 0x0c, 0x06, 0x08, 0x2a, 0x86,0x48,
0x86, 0xf7, 0x0d, 0x02, 0x05, 0x05, 0x00, 0x04, 0x10 };
if( algo != 1 )
return NULL;
*contextsize = sizeof(MD2_CONTEXT);
*r_asnoid = asn;
*r_asnlen = DIM(asn);
*r_mdlen = 16;
*(void (**)(MD2_CONTEXT *))r_init = md2_init;
*(void (**)(MD2_CONTEXT *, byte*, size_t))r_write = md2_write;
*(void (**)(MD2_CONTEXT *))r_final = md2_final;
*(byte *(**)(MD2_CONTEXT *))r_read = md2_read;
return "MD2";
}
#ifndef IS_MODULE
static
#endif
const char * const gnupgext_version = "MD2 ($Revision: 1.4 $)";
static struct {
int class;
int version;
int value;
void (*func)(void);
} func_table[] = {
{ 10, 1, 0, (void(*)(void))md2_get_info },
{ 11, 1, 1 },
};
#ifndef IS_MODULE
static
#endif
void *
gnupgext_enum_func( int what, int *sequence, int *class, int *vers )
{
void *ret;
int i = *sequence;
do {
if( i >= DIM(func_table) || i < 0 )
return NULL;
*class = func_table[i].class;
*vers = func_table[i].version;
switch( *class ) {
case 11: case 21: case 31: ret = &func_table[i].value; break;
default: ret = func_table[i].func; break;
}
i++;
} while( what && what != *class );
*sequence = i;
return ret;
}
#ifndef IS_MODULE
void
_gcry_md2_constructor(void)
{
_gcry_register_internal_cipher_extension( gnupgext_version, gnupgext_enum_func );
}
#endif
#endif
/* end of file */