diff options
Diffstat (limited to 'openssl/engines/ccgost/gost_keywrap.c')
| -rw-r--r-- | openssl/engines/ccgost/gost_keywrap.c | 109 |
1 files changed, 109 insertions, 0 deletions
diff --git a/openssl/engines/ccgost/gost_keywrap.c b/openssl/engines/ccgost/gost_keywrap.c new file mode 100644 index 000000000..c618f6da2 --- /dev/null +++ b/openssl/engines/ccgost/gost_keywrap.c @@ -0,0 +1,109 @@ +/********************************************************************** + * 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; + } + + |