1 /**********************************************************************
3 * Copyright (c) 2005-2006 Cryptocom LTD *
4 * This file is distributed under the same license as OpenSSL *
6 * Implementation of GOST R 34.11-94 hash function *
7 * uses on gost89.c and gost89.h Doesn't need OpenSSL *
8 **********************************************************************/
15 /* Use OPENSSL_malloc for memory allocation if compiled with
16 * -DOPENSSL_BUILD, and libc malloc otherwise
20 # include <openssl/crypto.h>
21 # define MYALLOC(size) OPENSSL_malloc(size)
22 # define MYFREE(ptr) OPENSSL_free(ptr)
24 # define MYALLOC(size) malloc(size)
25 # define MYFREE(ptr) free(ptr)
28 /* Following functions are various bit meshing routines used in
29 * GOST R 34.11-94 algorithms */
30 static void swap_bytes (byte *w, byte *k)
40 static void circle_xor8 (const byte *w, byte *k)
51 static void transform_3 (byte *data)
53 unsigned short int acc;
54 acc=(data[0]^data[2]^data[4]^data[6]^data[24]^data[30])|
55 ((data[1]^data[3]^data[5]^data[7]^data[25]^data[31])<<8);
56 memmove(data,data+2,30);
61 /* Adds blocks of N bytes modulo 2**(8*n). Returns carry*/
62 static int add_blocks(int n,byte *left, const byte *right)
69 sum=(int)left[i]+(int)right[i]+carry;
76 /* Xor two sequences of bytes */
77 static void xor_blocks (byte *result,const byte *a,const byte *b,size_t len)
80 for (i=0;i<len;i++) result[i]=a[i]^b[i];
84 * Calculate H(i+1) = Hash(Hi,Mi)
85 * Where H and M are 32 bytes long
87 static int hash_step(gost_ctx *c,byte *H,const byte *M)
89 byte U[32],W[32],V[32],S[32],Key[32];
91 /* Compute first key */
94 /* Encrypt first 8 bytes of H with first key*/
95 gost_enc_with_key(c,Key,H,S);
96 /* Compute second key*/
100 xor_blocks(W,U,V,32);
102 /* encrypt second 8 bytes of H with second key*/
103 gost_enc_with_key(c,Key,H+8,S+8);
104 /* compute third key */
106 U[31]=~U[31]; U[29]=~U[29]; U[28]=~U[28]; U[24]=~U[24];
107 U[23]=~U[23]; U[20]=~U[20]; U[18]=~U[18]; U[17]=~U[17];
108 U[14]=~U[14]; U[12]=~U[12]; U[10]=~U[10]; U[ 8]=~U[ 8];
109 U[ 7]=~U[ 7]; U[ 5]=~U[ 5]; U[ 3]=~U[ 3]; U[ 1]=~U[ 1];
112 xor_blocks(W,U,V,32);
114 /* encrypt third 8 bytes of H with third key*/
115 gost_enc_with_key(c,Key,H+16,S+16);
116 /* Compute fourth key */
120 xor_blocks(W,U,V,32);
122 /* Encrypt last 8 bytes with fourth key */
123 gost_enc_with_key(c,Key,H+24,S+24);
126 xor_blocks(S,S,M,32);
128 xor_blocks(S,S,H,32);
135 /* Initialize gost_hash ctx - cleans up temporary structures and
136 * set up substitution blocks
138 int init_gost_hash_ctx(gost_hash_ctx *ctx, const gost_subst_block *subst_block)
140 memset(ctx,0,sizeof(gost_hash_ctx));
141 ctx->cipher_ctx = (gost_ctx *)MYALLOC(sizeof(gost_ctx));
142 if (!ctx->cipher_ctx)
146 gost_init(ctx->cipher_ctx,subst_block);
151 * Free cipher CTX if it is dynamically allocated. Do not use
152 * if cipher ctx is statically allocated as in OpenSSL implementation of
153 * GOST hash algroritm
156 void done_gost_hash_ctx(gost_hash_ctx *ctx)
158 /* No need to use gost_destroy, because cipher keys are not really
159 * secret when hashing */
160 MYFREE(ctx->cipher_ctx);
164 * reset state of hash context to begin hashing new message
166 int start_hash(gost_hash_ctx *ctx)
168 if (!ctx->cipher_ctx) return 0;
169 memset(&(ctx->H),0,32);
170 memset(&(ctx->S),0,32);
177 * Hash block of arbitrary length
181 int hash_block(gost_hash_ctx *ctx,const byte *block, size_t length)
183 const byte *curptr=block;
184 const byte *barrier=block+(length-32);/* Last byte we can safely hash*/
187 /*There are some bytes from previous step*/
188 unsigned int add_bytes = 32-ctx->left;
189 if (add_bytes>length)
193 memcpy(&(ctx->remainder[ctx->left]),block,add_bytes);
194 ctx->left+=add_bytes;
199 curptr=block+add_bytes;
200 hash_step(ctx->cipher_ctx,ctx->H,ctx->remainder);
201 add_blocks(32,ctx->S,ctx->remainder);
205 while (curptr<=barrier)
207 hash_step(ctx->cipher_ctx,ctx->H,curptr);
209 add_blocks(32,ctx->S,curptr);
213 if (curptr!=block+length)
215 ctx->left=block+length-curptr;
216 memcpy(ctx->remainder,curptr,ctx->left);
222 * Compute hash value from current state of ctx
223 * state of hash ctx becomes invalid and cannot be used for further
226 int finish_hash(gost_hash_ctx *ctx,byte *hashval)
231 ghosthash_len fin_len=ctx->len;
238 memcpy(buf,ctx->remainder,ctx->left);
239 hash_step(ctx->cipher_ctx,H,buf);
240 add_blocks(32,S,buf);
245 fin_len<<=3; /* Hash length in BITS!!*/
248 *(bptr++)=(byte)(fin_len&0xFF);
251 hash_step(ctx->cipher_ctx,H,buf);
252 hash_step(ctx->cipher_ctx,H,S);
253 memcpy(hashval,H,32);