1 /**********************************************************************
3 * Copyright (c) 2005-2006 Cryptocom LTD *
4 * This file is distributed under the same license as OpenSSL *
6 * Implementation of CryptoPro key wrap algorithm, as defined in *
7 * RFC 4357 p 6.3 and 6.4 *
8 * Doesn't need OpenSSL *
9 **********************************************************************/
14 /* Diversifies key using random UserKey Material
15 * Implements RFC 4357 p 6.5 key diversification algorithm
17 * inputKey - 32byte key to be diversified
18 * ukm - 8byte user key material
19 * outputKey - 32byte buffer to store diversified key
22 void keyDiversifyCryptoPro(gost_ctx *ctx,const unsigned char *inputKey, const unsigned char *ukm, unsigned char *outputKey)
28 memcpy(outputKey,inputKey,32);
30 /* Make array of integers from key */
33 for (j=0,mask=1;j<8;j++,mask<<=1) {
34 k=((u4)outputKey[4*j])|(outputKey[4*j+1]<<8)|
35 (outputKey[4*j+2]<<16)|(outputKey[4*j+3]<<24);
42 S[0]=s1&0xff; S[1]=(s1>>8)&0xff; S[2]=(s1>>16)&0xff; S[3]=(s1>>24)&0xff;
43 S[4]=s2&0xff; S[5]=(s2>>8)&0xff; S[6]=(s2>>16)&0xff; S[7]=(s2>>24)&0xff;
44 gost_key(ctx,outputKey);
45 gost_enc_cfb(ctx,S,outputKey,outputKey,4);
51 * Wraps key using RFC 4357 6.3
52 * ctx - gost encryption context, initialized with some S-boxes
53 * keyExchangeKey (KEK) 32-byte (256-bit) shared key
54 * ukm - 8 byte (64 bit) user key material,
55 * sessionKey - 32-byte (256-bit) key to be wrapped
56 * wrappedKey - 44-byte buffer to store wrapped key
59 int keyWrapCryptoPro(gost_ctx *ctx,const unsigned char *keyExchangeKey, const unsigned char *ukm,
60 const unsigned char *sessionKey, unsigned char *wrappedKey)
62 unsigned char kek_ukm[32];
63 keyDiversifyCryptoPro(ctx,keyExchangeKey,ukm,kek_ukm);
64 gost_key(ctx,kek_ukm);
65 memcpy(wrappedKey,ukm,8);
66 gost_enc(ctx,sessionKey,wrappedKey+8,4);
67 gost_mac_iv(ctx,32,ukm,sessionKey,32,wrappedKey+40);
71 * Unwraps key using RFC 4357 6.4
72 * ctx - gost encryption context, initialized with some S-boxes
73 * keyExchangeKey 32-byte shared key
74 * wrappedKey 44 byte key to be unwrapped (concatenation of 8-byte UKM,
75 * 32 byte encrypted key and 4 byte MAC
77 * sessionKEy - 32byte buffer to store sessionKey in
78 * Returns 1 if key is decrypted successfully, and 0 if MAC doesn't match
81 int keyUnwrapCryptoPro(gost_ctx *ctx,const unsigned char *keyExchangeKey,
82 const unsigned char *wrappedKey, unsigned char *sessionKey)
84 unsigned char kek_ukm[32],cek_mac[4];
85 keyDiversifyCryptoPro(ctx,keyExchangeKey,wrappedKey
86 /* First 8 bytes of wrapped Key is ukm */
88 gost_key(ctx,kek_ukm);
89 gost_dec(ctx,wrappedKey+8,sessionKey,4);
90 gost_mac_iv(ctx,32,wrappedKey,sessionKey,32,cek_mac);
91 if (memcmp(cek_mac,wrappedKey+40,4)) {