X-Git-Url: https://hackdaworld.org/gitweb/?p=my-code%2Fcrypto.git;a=blobdiff_plain;f=des.c;h=722e1cc790443797137eab823fd245fd3519cb90;hp=29cfa9426412e259a31037eed5ba5235a436085d;hb=813819fc21f3a9ebada1f6b4caef59be10ea07dc;hpb=324bac8319d6f902630b109a7ca50b3a28fa5330

diff --git a/des.c b/des.c
index 29cfa94..722e1cc 100644
--- a/des.c
+++ b/des.c
@@ -5,83 +5,223 @@
  *
  */
 
+#include <string.h>
 #include "des.h"
 
-u8 key_perm_table[DES_SUBKEY_LEN]={
+u8 key_perm_table[DES_INITIAL_KEY_LEN]={
  57,49,41,33,25,17,9,1,58,50,42,34,26,18,
  10,2,59,51,43,35,27,18,11,3,60,52,44,36,
  63,55,47,39,31,23,15,7,62,54,46,38,30,22,
  14,6,61,53,45,37,29,21,13,5,28,20,12,4
 };
 
-u8 rot_per_round_table[DES_ROUNDS]={
+u8 rot_per_round_table[DES_SUBKEYS]={
  1,1,2,2,2,2,2,2,1,2,2,2,2,2,2,1
 };
 
-u8 subkey_perm_table[DES_PERMC_LEN]={
+u8 subkey_perm_table[DES_SUBKEY_LEN]={
  14,17,11,24,1,5,3,28,15,6,21,10,
  23,19,12,4,26,8,16,7,27,20,13,2,
  41,52,31,37,47,55,30,40,51,45,33,48,
  44,49,39,56,34,53,46,42,50,36,29,32
 };
 
+u8 data_perm_table[DES_DATA_BLOCK_LEN]={
+ 58,50,42,34,26,18,10,2,60,52,44,36,28,20,12,4,
+ 62,54,46,38,30,22,14,6,64,56,48,40,32,24,16,8,
+ 57,49,41,33,25,17,9,1,59,51,43,35,27,19,11,3,
+ 61,53,45,37,29,21,13,5,63,55,47,39,31,23,15,7
+};
+
+u8 data_expansion_table[DES_SUBKEY_LEN]={
+ 32,1,2,3,4,5,4,5,6,7,8,9,
+ 8,9,10,11,12,13,12,13,14,15,16,17,
+ 16,17,18,19,20,21,20,21,22,23,24,25,
+ 24,25,26,27,28,29,28,29,30,31,32,1
+};
+
+u8 sbox[DES_SBOXES][DES_SBOX_LEN]={
+ {14,4,13,1,2,15,11,8,3,10,6,12,5,9,0,7,
+  0,15,7,4,14,2,13,1,10,6,12,11,9,5,3,8,
+  4,1,14,8,13,6,2,11,15,12,9,7,3,10,5,0,
+  15,12,8,2,4,9,1,7,5,11,3,14,10,0,6,13},
+ {15,1,8,14,6,11,3,4,9,7,2,13,12,0,5,10,
+  3,13,4,7,15,2,8,14,12,0,1,10,6,9,11,5,
+  0,14,7,11,10,4,13,1,5,8,12,6,9,3,2,15,
+  13,8,10,1,3,15,4,2,11,6,7,12,0,5,14,9},
+ {10,0,9,14,6,3,15,5,1,13,12,7,11,4,2,8,
+  13,7,0,9,3,4,6,10,2,8,5,14,12,11,15,1,
+  13,6,4,9,8,15,3,0,11,1,2,12,5,10,14,7,
+  1,10,13,0,6,9,8,7,4,15,14,3,11,5,2,12},
+ {7,13,14,3,0,6,9,10,1,2,8,5,11,12,4,15,
+  13,8,11,5,6,15,0,3,4,7,2,12,1,10,14,9,
+  10,6,9,0,12,11,7,13,15,1,3,14,5,2,8,4,
+  3,15,0,6,10,1,13,8,9,4,5,11,12,7,2,14},
+ {2,12,4,1,7,10,11,6,8,5,3,15,13,0,14,9,
+  14,11,2,12,4,7,13,1,5,0,15,10,3,9.8,6,
+  4,2,1,11,10,13,7,8,15,9,12,5,6,3,0,14,
+  11,8,12,7,1,14,2,13,6,15,0,9,10,4,5,3},
+ {12,1,10,15,9,2,6,8,0,13,3,4,14,7,5,11,
+  10,15,4,2,7,12,9,5,6,1,13,14,0,11,3,8,
+  9,14,15,5,2,8,12,3,7,0,4,10,1,13,11,6,
+  4,3,2,12,9,5,15,10,11,14,1,7,6,0,8,13},
+ {4,11,2,14,15,0,8,13,3,12,9,7,5,10,6,1,
+  13,0,11,7,4,9,1,10,14,3,5,12,2,15,8,6,
+  1,4,11,13,12,3,7,14,10,15,6,8,0,5,9,2,
+  6,11,13,8,1,4,10,7,9,5,0,15,14,2,3,12},
+ {13,2,8,4,6,15,11,1,10,9,3,14,5,0,12,7,
+  1,15,13,8,10,3,7,4,12,5,6,11,0,14,9,2,
+  7,11,4,1,9,12,14,2,0,6,10,13,15,3,5,8,
+  2,1,14,7,4,10,8,13,15,12,9,0,3,5,6,11}
+};
+
+u8 pbox[DES_PBOX_LEN]={
+ 16,7,20,21,29,12,28,17,1,15,23,26,5,18,31,10,
+ 2,8,24,14,32,27,3,9,19,13,30,6,22,11,4,25
+};
+
+u8 data_final_perm_table[DES_DATA_BLOCK_LEN]={
+ 40,8,48,16,56,24,64,32,39,7,47,15,55,23,63,31,
+ 38,6,46,14,54,22,62,30,37,5,45,13,53,21,61,29,
+ 36,4,44,12,52,20,60,28,35,3,43,11,51,19,59,27,
+ 34,2,42,10,50,18,58,26,33,1,41,9,49,17,57,25
+};
+
 int rotate_right(u8 *obj,int len) {
  u8 tmp=obj[len-1];
- while(--len) obj[len]=obj[len-1];
- obj[0]=tmp;
+ while(--len) obj[len]=obj[len]>>1|((obj[len-1]&1)<<7);
+ obj[0]=obj[0]>>1|((tmp&1)<<7);;
  return 1;
 }
 
 int rotate_left(u8 *obj,int len) {
  int i=0;
  u8 tmp=obj[0];
- while(len-(i++)) obj[i-1]=obj[i];
- obj[len-1]=tmp;
+ for(i=0;i<len-1;i++) obj[i]=obj[i]<<1|(obj[i+1]>>7);
+ obj[len-1]=obj[len-1]<<1|(tmp>>7);
  return 1;
 }
 
-key_perm(u8 *key) {
+int table_trans(u8 *src,u8 *final,u8 *table,int len) {
  int i;
- u8 *new[DES_SUBKEY_LEN/8];
- memset(new,0,DES_SUBKEY_LEN/8];
- for(i=0;i<DES_SUBKEY_LEN;i++)
-  new[i/8]|=(key[key_perm_table[i]/8]>>((8-key_perm_table[i]%8)%8);
- memcpy(key,new,DES_SUBKEY_LEN);
+ memset(final,0,len/8);
+ for(i=0;i<len;i++)
+  final[i/8]|=((((src[(table[i]-1)/8])>>((8-table[i]%8)&7))&1)<<(7-i%8));
  return 1;
 }
 
 int subkey_trans(u8 *key,int round) {
  int i;
  for(i=0;i<rot_per_round_table[round];i++) {
-  rotate_left(key,DES_SUBKEY_LEN/2);
-  rotate_left(key+DES_SUBKEY_LEN/2,DES_SUBKEY_LEN/2);
+  rotate_left(key,DES_INITIAL_KEY_LEN/(8*2));
+  rotate_left(key+DES_INITIAL_KEY_LEN/(8*2),DES_INITIAL_KEY_LEN/(8*2));
+ }
+ return 1;
+}
+
+int compute_subkeys(u8 *key0,u8 subkey[DES_SUBKEYS][DES_SUBKEY_LEN/8]) {
+ int i;
+ u8 key0_56[DES_INITIAL_KEY_LEN/8];
+ /* initial permutation of key */
+ table_trans(key0,key0_56,key_perm_table,DES_INITIAL_KEY_LEN);
+ for(i=0;i<DES_SUBKEYS;i++) {
+  /* split and rotate key_056 */
+  subkey_trans(key0_56,i);
+  /* chose 48 bits as a subkey */
+  table_trans(key0_56,subkey[i],subkey_perm_table,DES_SUBKEY_LEN);
  }
  return 1;
 }
 
-int fuckup_data(u8 *key,int round,u8 *plain,u8 *crypted) {
- u8 permc[DES_PERMC_LEN];
+int get_sbox_value(u8 *data,int offset,int len,int box) {
+ int tmp;
+ tmp=((offset%8)==0)?data[offset/8]>>(8-len):((data[offset/8]&((1<<(offset%8))-1))<<(offset%8))|(data[(offset/8)+1]>>(len-(8-(offset%8))));
+ return(sbox[box][((tmp&1)|(tmp&(1<<(len-1))<<1))*16+(tmp&((1<<(len-1))-1)>>1)]); 
+}
+
+int data_s_and_p(u8 *data) {
+ u8 s[DES_DATA_BLOCK_LEN/(8*2)];
  int i;
- for(i=0;i<DES_PERMC_LEN;i++)
-  permc[i]=key[subkey_perm_table[i]];
- 
+ for(i=0;i<DES_SBOXES;i++)
+  s[i]=get_sbox_value(data,i*(DES_SUBKEY_LEN/DES_SBOXES),(DES_SUBKEY_LEN/DES_SBOXES),i);
+ table_trans(s,data,pbox,DES_PBOX_LEN);
  return 1;
 }
 
-int des_crypt(u8 *plain,u8 *crypted,u8 *key) {
- int round;
+int progress_data(u8 *data,u8 *crypted,u8 subkey[DES_SUBKEYS][DES_SUBKEY_LEN/8],u8 mode) {
+ int i,j;
+ u8 permuted_data[DES_DATA_BLOCK_LEN/8];
+ u8 left[DES_DATA_BLOCK_LEN/(2*8)];
+ u8 right[DES_DATA_BLOCK_LEN/(2*8)];
+ u8 tmp[DES_DATA_BLOCK_LEN/(2*8)];
 
- key_perm(key);
- for(round=0;round<DES_ROUND;round++) {
-  subkey_trans(key,round);
-  // fuckup_data(key,round,plain,crypted);
+ /* initial permutation */
+ table_trans(data,permuted_data,data_perm_table,DES_DATA_BLOCK_LEN);
+ memcpy(left,permuted_data,DES_DATA_BLOCK_LEN/(2*8));
+ memcpy(right,permuted_data+DES_DATA_BLOCK_LEN/(2*8),DES_DATA_BLOCK_LEN/(2*8));
+ for(i=0;i<DES_SUBKEYS;i++){
+  /* expand right data to 48 bit */
+  table_trans(right,permuted_data,data_expansion_table,DES_SUBKEY_LEN);
+  /* xor with subkey */
+  for(j=0;j<DES_SUBKEY_LEN/8;j++) permuted_data[j]^=subkey[mode&MODE_CRYPT?i:DES_SUBKEYS-1-i][j];
+  /* sbox substitutions and pbox permutations */
+  data_s_and_p(permuted_data);
+  /* xor with left data */
+  memcpy(tmp,right,DES_DATA_BLOCK_LEN/(2*8));
+  for(j=0;j<DES_DATA_BLOCK_LEN/(2*8);j++)    
+   right[j]=permuted_data[j]^left[j];
+  /* switch left and right data - not for last round */
+  if(i!=15) memcpy(left,tmp,DES_DATA_BLOCK_LEN/(2*8)); 
  }
-
+ /* merge and do final permutation */
+ memcpy(permuted_data,left,DES_DATA_BLOCK_LEN/(2*8));
+ memcpy(permuted_data+DES_DATA_BLOCK_LEN/(2*8),right,DES_DATA_BLOCK_LEN/(8*2));
+ table_trans(permuted_data,crypted,data_final_perm_table,DES_DATA_BLOCK_LEN);
  return 1;
 }
 
-int des_decrypt(u8 *crypted,u8 *plain,u8 *key) {
+int des_crypt_decrypt(u8 *src,u8 *final,u8 *key,int len,u8 mode) {
+ u8 subkey[DES_SUBKEYS][DES_SUBKEY_LEN/8];
+ int i,j;
+ /* compute the subkeys:
+    - initial key transformation: 64bit -> 56bit
+    - obtain subkeys by:
+      - split 56bit key -> 28bit - 28bit
+      - rotate these to the left (rotation depends on round)
+      - merge them again -> 56bit
+      - do permuted choice -> 56bit -> 48 bit, the subkey
+      - loop 16 times
+ */
+ compute_subkeys(key,subkey);
+ /* split data to 64bit blocks, and crypt/decrypt each block
+    depending on mode (CBC/ECB):
+    - initial data transformation
+    - crypt data:
+      - split 64bit data -> 32bit - 32bit
+      - expand right data block
+      - xor right block with subkey i (or 15-i)
+      - do sbox and pbox permutations
+      - xor result with left data block
+      - switch left and right data block (not for last cycle)
+      - loop 16 times
+    - do final permutation
+ */
+ for(i=0;i<len/8;i++) {
+  if((mode&MODE_CBC)&&(mode&MODE_CRYPT)&&(i!=0))
+   for(j=0;j<8;j++) src[i*8+j]^=final[(i-1)*8+j];
+  progress_data(src+i*8,final+i*8,subkey,mode);
+  if((mode&MODE_CBC)&&(mode&MODE_DECRYPT)&&(i!=0))
+   for(j=0;j<8;j++) final[(i*8)+j]^=src[(i-1)*8+j];
+ }  
+ return 1;
+}
 
+int des_encrypt(u8 *plain,u8 *crypted,u8 *key,int len,u8 mode) {
+ des_crypt_decrypt(plain,crypted,key,len,MODE_CRYPT|mode);
+ return 1;
+}
 
+int des_decrypt(u8 *crypted,u8 *plain,u8 *key,int len,u8 mode) {
+ des_crypt_decrypt(crypted,plain,key,len,MODE_DECRYPT|mode);
  return 1;
 }