1/********************************************************************** 2 * keywrap.c * 3 * Copyright (c) 2005-2006 Cryptocom LTD * 4 * This file is distributed under the same license as OpenSSL * 5 * * 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 **********************************************************************/ 10#include <string.h> 11#include "gost89.h" 12#include "gost_keywrap.h" 13
| 1/********************************************************************** 2 * keywrap.c * 3 * Copyright (c) 2005-2006 Cryptocom LTD * 4 * This file is distributed under the same license as OpenSSL * 5 * * 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 **********************************************************************/ 10#include <string.h> 11#include "gost89.h" 12#include "gost_keywrap.h" 13
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14/* Diversifies key using random UserKey Material 15 * Implements RFC 4357 p 6.5 key diversification algorithm 16 *
| 14/*- 15 * Diversifies key using random UserKey Material 16 * Implements RFC 4357 p 6.5 key diversification algorithm 17 *
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17 * inputKey - 32byte key to be diversified 18 * ukm - 8byte user key material
| 18 * inputKey - 32byte key to be diversified 19 * ukm - 8byte user key material
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19 * outputKey - 32byte buffer to store diversified key
| 20 * outputKey - 32byte buffer to store diversified key
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20 * 21 */
| 21 * 22 */
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22void keyDiversifyCryptoPro(gost_ctx *ctx,const unsigned char *inputKey, const unsigned char *ukm, unsigned char *outputKey) 23 {
| 23void keyDiversifyCryptoPro(gost_ctx * ctx, const unsigned char *inputKey, 24 const unsigned char *ukm, unsigned char *outputKey) 25{
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24
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25 u4 k,s1,s2; 26 int i,j,mask; 27 unsigned char S[8]; 28 memcpy(outputKey,inputKey,32); 29 for (i=0;i<8;i++) 30 { 31 /* Make array of integers from key */ 32 /* Compute IV S*/ 33 s1=0,s2=0; 34 for (j=0,mask=1;j<8;j++,mask<<=1) 35 { 36 k=((u4)outputKey[4*j])|(outputKey[4*j+1]<<8)| 37 (outputKey[4*j+2]<<16)|(outputKey[4*j+3]<<24); 38 if (mask & ukm[i]) 39 { 40 s1+=k; 41 } 42 else 43 { 44 s2+=k; 45 } 46 } 47 S[0]=(unsigned char)(s1&0xff); 48 S[1]=(unsigned char)((s1>>8)&0xff); 49 S[2]=(unsigned char)((s1>>16)&0xff); 50 S[3]=(unsigned char)((s1>>24)&0xff); 51 S[4]=(unsigned char)(s2&0xff); 52 S[5]=(unsigned char)((s2>>8)&0xff); 53 S[6]=(unsigned char)((s2>>16)&0xff); 54 S[7]=(unsigned char)((s2>>24)&0xff); 55 gost_key(ctx,outputKey); 56 gost_enc_cfb(ctx,S,outputKey,outputKey,4); 57 } 58 } 59
| 27 u4 k, s1, s2; 28 int i, j, mask; 29 unsigned char S[8]; 30 memcpy(outputKey, inputKey, 32); 31 for (i = 0; i < 8; i++) { 32 /* Make array of integers from key */ 33 /* Compute IV S */ 34 s1 = 0, s2 = 0; 35 for (j = 0, mask = 1; j < 8; j++, mask <<= 1) { 36 k = ((u4) outputKey[4 * j]) | (outputKey[4 * j + 1] << 8) | 37 (outputKey[4 * j + 2] << 16) | (outputKey[4 * j + 3] << 24); 38 if (mask & ukm[i]) { 39 s1 += k; 40 } else { 41 s2 += k; 42 } 43 } 44 S[0] = (unsigned char)(s1 & 0xff); 45 S[1] = (unsigned char)((s1 >> 8) & 0xff); 46 S[2] = (unsigned char)((s1 >> 16) & 0xff); 47 S[3] = (unsigned char)((s1 >> 24) & 0xff); 48 S[4] = (unsigned char)(s2 & 0xff); 49 S[5] = (unsigned char)((s2 >> 8) & 0xff); 50 S[6] = (unsigned char)((s2 >> 16) & 0xff); 51 S[7] = (unsigned char)((s2 >> 24) & 0xff); 52 gost_key(ctx, outputKey); 53 gost_enc_cfb(ctx, S, outputKey, outputKey, 4); 54 } 55}
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60
| 56
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61/*
| 57/*-
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62 * Wraps key using RFC 4357 6.3
| 58 * Wraps key using RFC 4357 6.3
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63 * ctx - gost encryption context, initialized with some S-boxes
| 59 * ctx - gost encryption context, initialized with some S-boxes
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64 * keyExchangeKey (KEK) 32-byte (256-bit) shared key
| 60 * keyExchangeKey (KEK) 32-byte (256-bit) shared key
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65 * ukm - 8 byte (64 bit) user key material,
| 61 * ukm - 8 byte (64 bit) user key material,
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66 * sessionKey - 32-byte (256-bit) key to be wrapped 67 * wrappedKey - 44-byte buffer to store wrapped key
| 62 * sessionKey - 32-byte (256-bit) key to be wrapped 63 * wrappedKey - 44-byte buffer to store wrapped key
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68 */
| 64 */
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69
| 65
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70int keyWrapCryptoPro(gost_ctx *ctx,const unsigned char *keyExchangeKey, const unsigned char *ukm, 71 const unsigned char *sessionKey, unsigned char *wrappedKey) 72 { 73 unsigned char kek_ukm[32]; 74 keyDiversifyCryptoPro(ctx,keyExchangeKey,ukm,kek_ukm); 75 gost_key(ctx,kek_ukm); 76 memcpy(wrappedKey,ukm,8); 77 gost_enc(ctx,sessionKey,wrappedKey+8,4); 78 gost_mac_iv(ctx,32,ukm,sessionKey,32,wrappedKey+40); 79 return 1; 80 } 81/*
| 66int keyWrapCryptoPro(gost_ctx * ctx, const unsigned char *keyExchangeKey, 67 const unsigned char *ukm, 68 const unsigned char *sessionKey, 69 unsigned char *wrappedKey) 70{ 71 unsigned char kek_ukm[32]; 72 keyDiversifyCryptoPro(ctx, keyExchangeKey, ukm, kek_ukm); 73 gost_key(ctx, kek_ukm); 74 memcpy(wrappedKey, ukm, 8); 75 gost_enc(ctx, sessionKey, wrappedKey + 8, 4); 76 gost_mac_iv(ctx, 32, ukm, sessionKey, 32, wrappedKey + 40); 77 return 1; 78} 79 80/*-
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82 * Unwraps key using RFC 4357 6.4
| 81 * Unwraps key using RFC 4357 6.4
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83 * ctx - gost encryption context, initialized with some S-boxes
| 82 * ctx - gost encryption context, initialized with some S-boxes
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84 * keyExchangeKey 32-byte shared key 85 * wrappedKey 44 byte key to be unwrapped (concatenation of 8-byte UKM,
| 83 * keyExchangeKey 32-byte shared key 84 * wrappedKey 44 byte key to be unwrapped (concatenation of 8-byte UKM,
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86 * 32 byte encrypted key and 4 byte MAC 87 *
| 85 * 32 byte encrypted key and 4 byte MAC 86 *
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88 * sessionKEy - 32byte buffer to store sessionKey in 89 * Returns 1 if key is decrypted successfully, and 0 if MAC doesn't match
| 87 * sessionKEy - 32byte buffer to store sessionKey in 88 * Returns 1 if key is decrypted successfully, and 0 if MAC doesn't match
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90 */
| 89 */
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91
| 90
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92int keyUnwrapCryptoPro(gost_ctx *ctx,const unsigned char *keyExchangeKey, 93 const unsigned char *wrappedKey, unsigned char *sessionKey) 94 { 95 unsigned char kek_ukm[32],cek_mac[4]; 96 keyDiversifyCryptoPro(ctx,keyExchangeKey,wrappedKey 97 /* First 8 bytes of wrapped Key is ukm */ 98 ,kek_ukm); 99 gost_key(ctx,kek_ukm); 100 gost_dec(ctx,wrappedKey+8,sessionKey,4); 101 gost_mac_iv(ctx,32,wrappedKey,sessionKey,32,cek_mac); 102 if (memcmp(cek_mac,wrappedKey+40,4)) 103 { 104 return 0; 105 } 106 return 1; 107 } 108 109
| 91int keyUnwrapCryptoPro(gost_ctx * ctx, const unsigned char *keyExchangeKey, 92 const unsigned char *wrappedKey, 93 unsigned char *sessionKey) 94{ 95 unsigned char kek_ukm[32], cek_mac[4]; 96 keyDiversifyCryptoPro(ctx, keyExchangeKey, wrappedKey 97 /* First 8 bytes of wrapped Key is ukm */ 98 , kek_ukm); 99 gost_key(ctx, kek_ukm); 100 gost_dec(ctx, wrappedKey + 8, sessionKey, 4); 101 gost_mac_iv(ctx, 32, wrappedKey, sessionKey, 32, cek_mac); 102 if (memcmp(cek_mac, wrappedKey + 40, 4)) { 103 return 0; 104 } 105 return 1; 106}
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