You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
110 lines
3.4 KiB
110 lines
3.4 KiB
14 years ago
|
/**********************************************************************
|
||
|
|
* keywrap.c *
|
||
|
|
* Copyright (c) 2005-2006 Cryptocom LTD *
|
||
|
|
* This file is distributed under the same license as OpenSSL *
|
||
|
|
* *
|
||
|
|
* Implementation of CryptoPro key wrap algorithm, as defined in *
|
||
|
|
* RFC 4357 p 6.3 and 6.4 *
|
||
|
|
* Doesn't need OpenSSL *
|
||
|
|
**********************************************************************/
|
||
|
|
#include <string.h>
|
||
|
|
#include "gost89.h"
|
||
|
|
#include "gost_keywrap.h"
|
||
|
|
|
||
|
|
/* Diversifies key using random UserKey Material
|
||
|
|
* Implements RFC 4357 p 6.5 key diversification algorithm
|
||
|
|
*
|
||
|
|
* inputKey - 32byte key to be diversified
|
||
|
|
* ukm - 8byte user key material
|
||
|
|
* outputKey - 32byte buffer to store diversified key
|
||
|
|
*
|
||
|
|
*/
|
||
|
|
void keyDiversifyCryptoPro(gost_ctx *ctx,const unsigned char *inputKey, const unsigned char *ukm, unsigned char *outputKey)
|
||
|
|
{
|
||
|
|
|
||
|
|
u4 k,s1,s2;
|
||
|
|
int i,j,mask;
|
||
|
|
unsigned char S[8];
|
||
|
|
memcpy(outputKey,inputKey,32);
|
||
|
|
for (i=0;i<8;i++)
|
||
|
|
{
|
||
|
|
/* Make array of integers from key */
|
||
|
|
/* Compute IV S*/
|
||
|
|
s1=0,s2=0;
|
||
|
|
for (j=0,mask=1;j<8;j++,mask<<=1)
|
||
|
|
{
|
||
|
|
k=((u4)outputKey[4*j])|(outputKey[4*j+1]<<8)|
|
||
|
|
(outputKey[4*j+2]<<16)|(outputKey[4*j+3]<<24);
|
||
|
|
if (mask & ukm[i])
|
||
|
|
{
|
||
|
|
s1+=k;
|
||
|
|
}
|
||
|
|
else
|
||
|
|
{
|
||
|
|
s2+=k;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
S[0]=(unsigned char)(s1&0xff);
|
||
|
|
S[1]=(unsigned char)((s1>>8)&0xff);
|
||
|
|
S[2]=(unsigned char)((s1>>16)&0xff);
|
||
|
|
S[3]=(unsigned char)((s1>>24)&0xff);
|
||
|
|
S[4]=(unsigned char)(s2&0xff);
|
||
|
|
S[5]=(unsigned char)((s2>>8)&0xff);
|
||
|
|
S[6]=(unsigned char)((s2>>16)&0xff);
|
||
|
|
S[7]=(unsigned char)((s2>>24)&0xff);
|
||
|
|
gost_key(ctx,outputKey);
|
||
|
|
gost_enc_cfb(ctx,S,outputKey,outputKey,4);
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
|
||
|
|
/*
|
||
|
|
* Wraps key using RFC 4357 6.3
|
||
|
|
* ctx - gost encryption context, initialized with some S-boxes
|
||
|
|
* keyExchangeKey (KEK) 32-byte (256-bit) shared key
|
||
|
|
* ukm - 8 byte (64 bit) user key material,
|
||
|
|
* sessionKey - 32-byte (256-bit) key to be wrapped
|
||
|
|
* wrappedKey - 44-byte buffer to store wrapped key
|
||
|
|
*/
|
||
|
|
|
||
|
|
int keyWrapCryptoPro(gost_ctx *ctx,const unsigned char *keyExchangeKey, const unsigned char *ukm,
|
||
|
|
const unsigned char *sessionKey, unsigned char *wrappedKey)
|
||
|
|
{
|
||
|
|
unsigned char kek_ukm[32];
|
||
|
|
keyDiversifyCryptoPro(ctx,keyExchangeKey,ukm,kek_ukm);
|
||
|
|
gost_key(ctx,kek_ukm);
|
||
|
|
memcpy(wrappedKey,ukm,8);
|
||
|
|
gost_enc(ctx,sessionKey,wrappedKey+8,4);
|
||
|
|
gost_mac_iv(ctx,32,ukm,sessionKey,32,wrappedKey+40);
|
||
|
|
return 1;
|
||
|
|
}
|
||
|
|
/*
|
||
|
|
* Unwraps key using RFC 4357 6.4
|
||
|
|
* ctx - gost encryption context, initialized with some S-boxes
|
||
|
|
* keyExchangeKey 32-byte shared key
|
||
|
|
* wrappedKey 44 byte key to be unwrapped (concatenation of 8-byte UKM,
|
||
|
|
* 32 byte encrypted key and 4 byte MAC
|
||
|
|
*
|
||
|
|
* sessionKEy - 32byte buffer to store sessionKey in
|
||
|
|
* Returns 1 if key is decrypted successfully, and 0 if MAC doesn't match
|
||
|
|
*/
|
||
|
|
|
||
|
|
int keyUnwrapCryptoPro(gost_ctx *ctx,const unsigned char *keyExchangeKey,
|
||
|
|
const unsigned char *wrappedKey, unsigned char *sessionKey)
|
||
|
|
{
|
||
|
|
unsigned char kek_ukm[32],cek_mac[4];
|
||
|
|
keyDiversifyCryptoPro(ctx,keyExchangeKey,wrappedKey
|
||
|
|
/* First 8 bytes of wrapped Key is ukm */
|
||
|
|
,kek_ukm);
|
||
|
|
gost_key(ctx,kek_ukm);
|
||
|
|
gost_dec(ctx,wrappedKey+8,sessionKey,4);
|
||
|
|
gost_mac_iv(ctx,32,wrappedKey,sessionKey,32,cek_mac);
|
||
|
|
if (memcmp(cek_mac,wrappedKey+40,4))
|
||
|
|
{
|
||
|
|
return 0;
|
||
|
|
}
|
||
|
|
return 1;
|
||
|
|
}
|
||
|
|
|
||
|
|
|