--- /dev/null
+/**********************************************************************
+ * gosthash.c *
+ * Copyright (c) 2005-2006 Cryptocom LTD *
+ * This file is distributed under the same license as OpenSSL *
+ * *
+ * Implementation of GOST R 34.11-94 hash function *
+ * uses on gost89.c and gost89.h Doesn't need OpenSSL *
+ **********************************************************************/
+#include <string.h>
+
+#include "gost89.h"
+#include "gosthash.h"
+
+
+/* Use OPENSSL_malloc for memory allocation if compiled with
+ * -DOPENSSL_BUILD, and libc malloc otherwise
+ */
+#ifndef MYALLOC
+# ifdef OPENSSL_BUILD
+# include <openssl/crypto.h>
+# define MYALLOC(size) OPENSSL_malloc(size)
+# define MYFREE(ptr) OPENSSL_free(ptr)
+# else
+# define MYALLOC(size) malloc(size)
+# define MYFREE(ptr) free(ptr)
+# endif
+#endif
+/* Following functions are various bit meshing routines used in
+ * GOST R 34.11-94 algorithms */
+static void swap_bytes (byte *w, byte *k)
+ {
+ int i,j;
+ for (i=0;i<4;i++)
+ for (j=0;j<8;j++)
+ k[i+4*j]=w[8*i+j];
+
+ }
+
+/* was A_A */
+static void circle_xor8 (const byte *w, byte *k)
+ {
+ byte buf[8];
+ int i;
+ memcpy(buf,w,8);
+ memmove(k,w+8,24);
+ for(i=0;i<8;i++)
+ k[i+24]=buf[i]^k[i];
+ }
+
+/* was R_R */
+static void transform_3 (byte *data)
+ {
+ unsigned short int acc;
+ acc=(data[0]^data[2]^data[4]^data[6]^data[24]^data[30])|
+ ((data[1]^data[3]^data[5]^data[7]^data[25]^data[31])<<8);
+ memmove(data,data+2,30);
+ data[30]=acc&0xff;
+ data[31]=acc>>8;
+ }
+
+/* Adds blocks of N bytes modulo 2**(8*n). Returns carry*/
+static int add_blocks(int n,byte *left, const byte *right)
+ {
+ int i;
+ int carry=0;
+ int sum;
+ for (i=0;i<n;i++)
+ {
+ sum=(int)left[i]+(int)right[i]+carry;
+ left[i]=sum & 0xff;
+ carry=sum>>8;
+ }
+ return carry;
+ }
+
+/* Xor two sequences of bytes */
+static void xor_blocks (byte *result,const byte *a,const byte *b,size_t len)
+ {
+ size_t i;
+ for (i=0;i<len;i++) result[i]=a[i]^b[i];
+ }
+
+/*
+ * Calculate H(i+1) = Hash(Hi,Mi)
+ * Where H and M are 32 bytes long
+ */
+static int hash_step(gost_ctx *c,byte *H,const byte *M)
+ {
+ byte U[32],W[32],V[32],S[32],Key[32];
+ int i;
+ /* Compute first key */
+ xor_blocks(W,H,M,32);
+ swap_bytes(W,Key);
+ /* Encrypt first 8 bytes of H with first key*/
+ gost_enc_with_key(c,Key,H,S);
+ /* Compute second key*/
+ circle_xor8(H,U);
+ circle_xor8(M,V);
+ circle_xor8(V,V);
+ xor_blocks(W,U,V,32);
+ swap_bytes(W,Key);
+ /* encrypt second 8 bytes of H with second key*/
+ gost_enc_with_key(c,Key,H+8,S+8);
+ /* compute third key */
+ circle_xor8(U,U);
+ U[31]=~U[31]; U[29]=~U[29]; U[28]=~U[28]; U[24]=~U[24];
+ U[23]=~U[23]; U[20]=~U[20]; U[18]=~U[18]; U[17]=~U[17];
+ U[14]=~U[14]; U[12]=~U[12]; U[10]=~U[10]; U[ 8]=~U[ 8];
+ U[ 7]=~U[ 7]; U[ 5]=~U[ 5]; U[ 3]=~U[ 3]; U[ 1]=~U[ 1];
+ circle_xor8(V,V);
+ circle_xor8(V,V);
+ xor_blocks(W,U,V,32);
+ swap_bytes(W,Key);
+ /* encrypt third 8 bytes of H with third key*/
+ gost_enc_with_key(c,Key,H+16,S+16);
+ /* Compute fourth key */
+ circle_xor8(U,U);
+ circle_xor8(V,V);
+ circle_xor8(V,V);
+ xor_blocks(W,U,V,32);
+ swap_bytes(W,Key);
+ /* Encrypt last 8 bytes with fourth key */
+ gost_enc_with_key(c,Key,H+24,S+24);
+ for (i=0;i<12;i++)
+ transform_3(S);
+ xor_blocks(S,S,M,32);
+ transform_3(S);
+ xor_blocks(S,S,H,32);
+ for (i=0;i<61;i++)
+ transform_3(S);
+ memcpy(H,S,32);
+ return 1;
+ }
+
+/* Initialize gost_hash ctx - cleans up temporary structures and
+ * set up substitution blocks
+ */
+int init_gost_hash_ctx(gost_hash_ctx *ctx, const gost_subst_block *subst_block)
+ {
+ memset(ctx,0,sizeof(gost_hash_ctx));
+ ctx->cipher_ctx = (gost_ctx *)MYALLOC(sizeof(gost_ctx));
+ if (!ctx->cipher_ctx)
+ {
+ return 0;
+ }
+ gost_init(ctx->cipher_ctx,subst_block);
+ return 1;
+ }
+
+/*
+ * Free cipher CTX if it is dynamically allocated. Do not use
+ * if cipher ctx is statically allocated as in OpenSSL implementation of
+ * GOST hash algroritm
+ *
+ */
+void done_gost_hash_ctx(gost_hash_ctx *ctx)
+ {
+ /* No need to use gost_destroy, because cipher keys are not really
+ * secret when hashing */
+ MYFREE(ctx->cipher_ctx);
+ }
+
+/*
+ * reset state of hash context to begin hashing new message
+ */
+int start_hash(gost_hash_ctx *ctx)
+ {
+ if (!ctx->cipher_ctx) return 0;
+ memset(&(ctx->H),0,32);
+ memset(&(ctx->S),0,32);
+ ctx->len = 0L;
+ ctx->left=0;
+ return 1;
+ }
+
+/*
+ * Hash block of arbitrary length
+ *
+ *
+ */
+int hash_block(gost_hash_ctx *ctx,const byte *block, size_t length)
+ {
+ if (ctx->left)
+ {
+ /*There are some bytes from previous step*/
+ unsigned int add_bytes = 32-ctx->left;
+ if (add_bytes>length)
+ {
+ add_bytes = length;
+ }
+ memcpy(&(ctx->remainder[ctx->left]),block,add_bytes);
+ ctx->left+=add_bytes;
+ if (ctx->left<32)
+ {
+ return 1;
+ }
+ block+=add_bytes;
+ length-=add_bytes;
+ hash_step(ctx->cipher_ctx,ctx->H,ctx->remainder);
+ add_blocks(32,ctx->S,ctx->remainder);
+ ctx->len+=32;
+ ctx->left=0;
+ }
+ while (length>=32)
+ {
+ hash_step(ctx->cipher_ctx,ctx->H,block);
+
+ add_blocks(32,ctx->S,block);
+ ctx->len+=32;
+ block+=32;
+ length-=32;
+ }
+ if (length)
+ {
+ memcpy(ctx->remainder,block,ctx->left=length);
+ }
+ return 1;
+ }
+
+/*
+ * Compute hash value from current state of ctx
+ * state of hash ctx becomes invalid and cannot be used for further
+ * hashing.
+ */
+int finish_hash(gost_hash_ctx *ctx,byte *hashval)
+ {
+ byte buf[32];
+ byte H[32];
+ byte S[32];
+ ghosthash_len fin_len=ctx->len;
+ byte *bptr;
+ memcpy(H,ctx->H,32);
+ memcpy(S,ctx->S,32);
+ if (ctx->left)
+ {
+ memset(buf,0,32);
+ memcpy(buf,ctx->remainder,ctx->left);
+ hash_step(ctx->cipher_ctx,H,buf);
+ add_blocks(32,S,buf);
+ fin_len+=ctx->left;
+ }
+ memset(buf,0,32);
+ bptr=buf;
+ fin_len<<=3; /* Hash length in BITS!!*/
+ while(fin_len>0)
+ {
+ *(bptr++)=(byte)(fin_len&0xFF);
+ fin_len>>=8;
+ };
+ hash_step(ctx->cipher_ctx,H,buf);
+ hash_step(ctx->cipher_ctx,H,S);
+ memcpy(hashval,H,32);
+ return 1;
+ }
projects / cassiopeia.git / blobdiff