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| 1 /********************************************************************** |
| 2 * gosthash.c * |
| 3 * Copyright (c) 2005-2006 Cryptocom LTD * |
| 4 * This file is distributed under the same license as OpenSSL * |
| 5 * * |
| 6 * Implementation of GOST R 34.11-94 hash function * |
| 7 * uses on gost89.c and gost89.h Doesn't need OpenSSL * |
| 8 **********************************************************************/ |
| 9 #include <string.h> |
| 10 |
| 11 #include "gost89.h" |
| 12 #include "gosthash.h" |
| 13 |
| 14 |
| 15 /* Use OPENSSL_malloc for memory allocation if compiled with |
| 16 * -DOPENSSL_BUILD, and libc malloc otherwise |
| 17 */ |
| 18 #ifndef MYALLOC |
| 19 # ifdef OPENSSL_BUILD |
| 20 # include <openssl/crypto.h> |
| 21 # define MYALLOC(size) OPENSSL_malloc(size) |
| 22 # define MYFREE(ptr) OPENSSL_free(ptr) |
| 23 # else |
| 24 # define MYALLOC(size) malloc(size) |
| 25 # define MYFREE(ptr) free(ptr) |
| 26 # endif |
| 27 #endif |
| 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) |
| 31 { |
| 32 int i,j; |
| 33 for (i=0;i<4;i++) |
| 34 for (j=0;j<8;j++) |
| 35 k[i+4*j]=w[8*i+j]; |
| 36 |
| 37 } |
| 38 |
| 39 /* was A_A */ |
| 40 static void circle_xor8 (const byte *w, byte *k) |
| 41 { |
| 42 byte buf[8]; |
| 43 int i; |
| 44 memcpy(buf,w,8); |
| 45 memcpy(k,w+8,24); |
| 46 for(i=0;i<8;i++) |
| 47 k[i+24]=buf[i]^k[i]; |
| 48 } |
| 49 |
| 50 /* was R_R */ |
| 51 static void transform_3 (byte *data) |
| 52 { |
| 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); |
| 57 data[30]=acc&0xff; |
| 58 data[31]=acc>>8; |
| 59 } |
| 60 |
| 61 /* Adds blocks of N bytes modulo 2**(8*n). Returns carry*/ |
| 62 static int add_blocks(int n,byte *left, const byte *right) |
| 63 { |
| 64 int i; |
| 65 int carry=0; |
| 66 int sum; |
| 67 for (i=0;i<n;i++) |
| 68 { |
| 69 sum=(int)left[i]+(int)right[i]+carry; |
| 70 left[i]=sum & 0xff; |
| 71 carry=sum>>8; |
| 72 } |
| 73 return carry; |
| 74 } |
| 75 |
| 76 /* Xor two sequences of bytes */ |
| 77 static void xor_blocks (byte *result,const byte *a,const byte *b,size_t len) |
| 78 { |
| 79 size_t i; |
| 80 for (i=0;i<len;i++) result[i]=a[i]^b[i]; |
| 81 } |
| 82 |
| 83 /* |
| 84 * Calculate H(i+1) = Hash(Hi,Mi) |
| 85 * Where H and M are 32 bytes long |
| 86 */ |
| 87 static int hash_step(gost_ctx *c,byte *H,const byte *M) |
| 88 { |
| 89 byte U[32],W[32],V[32],S[32],Key[32]; |
| 90 int i; |
| 91 /* Compute first key */ |
| 92 xor_blocks(W,H,M,32); |
| 93 swap_bytes(W,Key); |
| 94 /* Encrypt first 8 bytes of H with first key*/ |
| 95 gost_enc_with_key(c,Key,H,S); |
| 96 /* Compute second key*/ |
| 97 circle_xor8(H,U); |
| 98 circle_xor8(M,V); |
| 99 circle_xor8(V,V); |
| 100 xor_blocks(W,U,V,32); |
| 101 swap_bytes(W,Key); |
| 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 */ |
| 105 circle_xor8(U,U); |
| 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]; |
| 110 circle_xor8(V,V); |
| 111 circle_xor8(V,V); |
| 112 xor_blocks(W,U,V,32); |
| 113 swap_bytes(W,Key); |
| 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 */ |
| 117 circle_xor8(U,U); |
| 118 circle_xor8(V,V); |
| 119 circle_xor8(V,V); |
| 120 xor_blocks(W,U,V,32); |
| 121 swap_bytes(W,Key); |
| 122 /* Encrypt last 8 bytes with fourth key */ |
| 123 gost_enc_with_key(c,Key,H+24,S+24); |
| 124 for (i=0;i<12;i++) |
| 125 transform_3(S); |
| 126 xor_blocks(S,S,M,32); |
| 127 transform_3(S); |
| 128 xor_blocks(S,S,H,32); |
| 129 for (i=0;i<61;i++) |
| 130 transform_3(S); |
| 131 memcpy(H,S,32); |
| 132 return 1; |
| 133 } |
| 134 |
| 135 /* Initialize gost_hash ctx - cleans up temporary structures and |
| 136 * set up substitution blocks |
| 137 */ |
| 138 int init_gost_hash_ctx(gost_hash_ctx *ctx, const gost_subst_block *subst_block) |
| 139 { |
| 140 memset(ctx,0,sizeof(gost_hash_ctx)); |
| 141 ctx->cipher_ctx = (gost_ctx *)MYALLOC(sizeof(gost_ctx)); |
| 142 if (!ctx->cipher_ctx) |
| 143 { |
| 144 return 0; |
| 145 } |
| 146 gost_init(ctx->cipher_ctx,subst_block); |
| 147 return 1; |
| 148 } |
| 149 |
| 150 /* |
| 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 |
| 154 * |
| 155 */ |
| 156 void done_gost_hash_ctx(gost_hash_ctx *ctx) |
| 157 { |
| 158 /* No need to use gost_destroy, because cipher keys are not really |
| 159 * secret when hashing */ |
| 160 MYFREE(ctx->cipher_ctx); |
| 161 } |
| 162 |
| 163 /* |
| 164 * reset state of hash context to begin hashing new message |
| 165 */ |
| 166 int start_hash(gost_hash_ctx *ctx) |
| 167 { |
| 168 if (!ctx->cipher_ctx) return 0; |
| 169 memset(&(ctx->H),0,32); |
| 170 memset(&(ctx->S),0,32); |
| 171 ctx->len = 0L; |
| 172 ctx->left=0; |
| 173 return 1; |
| 174 } |
| 175 |
| 176 /* |
| 177 * Hash block of arbitrary length |
| 178 * |
| 179 * |
| 180 */ |
| 181 int hash_block(gost_hash_ctx *ctx,const byte *block, size_t length) |
| 182 { |
| 183 const byte *curptr=block; |
| 184 const byte *barrier=block+(length-32);/* Last byte we can safely hash*/ |
| 185 if (ctx->left) |
| 186 { |
| 187 /*There are some bytes from previous step*/ |
| 188 unsigned int add_bytes = 32-ctx->left; |
| 189 if (add_bytes>length) |
| 190 { |
| 191 add_bytes = length; |
| 192 } |
| 193 memcpy(&(ctx->remainder[ctx->left]),block,add_bytes); |
| 194 ctx->left+=add_bytes; |
| 195 if (ctx->left<32) |
| 196 { |
| 197 return 1; |
| 198 } |
| 199 curptr=block+add_bytes; |
| 200 hash_step(ctx->cipher_ctx,ctx->H,ctx->remainder); |
| 201 add_blocks(32,ctx->S,ctx->remainder); |
| 202 ctx->len+=32; |
| 203 ctx->left=0; |
| 204 } |
| 205 while (curptr<=barrier) |
| 206 { |
| 207 hash_step(ctx->cipher_ctx,ctx->H,curptr); |
| 208 |
| 209 add_blocks(32,ctx->S,curptr); |
| 210 ctx->len+=32; |
| 211 curptr+=32; |
| 212 } |
| 213 if (curptr!=block+length) |
| 214 { |
| 215 ctx->left=block+length-curptr; |
| 216 memcpy(ctx->remainder,curptr,ctx->left); |
| 217 } |
| 218 return 1; |
| 219 } |
| 220 |
| 221 /* |
| 222 * Compute hash value from current state of ctx |
| 223 * state of hash ctx becomes invalid and cannot be used for further |
| 224 * hashing. |
| 225 */ |
| 226 int finish_hash(gost_hash_ctx *ctx,byte *hashval) |
| 227 { |
| 228 byte buf[32]; |
| 229 byte H[32]; |
| 230 byte S[32]; |
| 231 ghosthash_len fin_len=ctx->len; |
| 232 byte *bptr; |
| 233 memcpy(H,ctx->H,32); |
| 234 memcpy(S,ctx->S,32); |
| 235 if (ctx->left) |
| 236 { |
| 237 memset(buf,0,32); |
| 238 memcpy(buf,ctx->remainder,ctx->left); |
| 239 hash_step(ctx->cipher_ctx,H,buf); |
| 240 add_blocks(32,S,buf); |
| 241 fin_len+=ctx->left; |
| 242 } |
| 243 memset(buf,0,32); |
| 244 bptr=buf; |
| 245 fin_len<<=3; /* Hash length in BITS!!*/ |
| 246 while(fin_len>0) |
| 247 { |
| 248 *(bptr++)=(byte)(fin_len&0xFF); |
| 249 fin_len>>=8; |
| 250 }; |
| 251 hash_step(ctx->cipher_ctx,H,buf); |
| 252 hash_step(ctx->cipher_ctx,H,S); |
| 253 memcpy(hashval,H,32); |
| 254 return 1; |
| 255 } |
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