-

diff --git a/des.c b/des.c
index db0aba84e072ca4aef5b391d4a4a71d36f5309f8..4c0a358218f22e269cbfc4b7b42f1dcd3211a433 100644 (file)
--- a/des.c
+++ b/des.c
@@ -14,17 +14,71 @@ u8 key_perm_table[DES_SUBKEY_LEN]={
  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
+}; 
+
 int rotate_right(u8 *obj,int len) {
  u8 tmp=obj[len-1];
  while(--len) obj[len]=obj[len]>>1|((obj[len-1]&1)<<7);
@@ -42,48 +96,133 @@ int rotate_left(u8 *obj,int len) {
 
 key_perm(u8 *key) {
  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]-1)/8)]>>((8-key_perm_table[i]%8)&7))&1)<<(7-i%8));
- memcpy(key,new,DES_SUBKEY_LEN);
+ u8 new[DES_INITIAL_KEY_LEN/8];
+ memset(new,0,DES_INITIAL_KEY_LEN/8];
+ for(i=0;i<DES_INITIAL_KEY_LEN;i++)
+   new[i/8]|=((((key[(key_perm_table[i]-1)/8)]>>((8-key_perm_table[i]%8)&7))&1)<<(7-i%8));
+ memcpy(key,new,DES_INITIAL_KEY_LEN);
  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/(8*2));
-  rotate_left(key+DES_SUBKEY_LEN/(8*2),DES_SUBKEY_LEN/(8*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 fuckup_data_block(u8 *key,int round,u8 *plain,u8 *crypted) {
- u8 permc[DES_PERMC_LEN];
+int subkey_perm(u8 *key,u8 *pc) {
  int i;
- memset(permc,0,DES_PERMC_LEN/8);
- for(i=0;i<DES_PERMC_LEN;i++)
-  permc[i/8]|=(((key[(subkey_perm_table[i]-1)/8]>>((8-subkey_perm_table[i]%8)&7)&1))<<(7-i%8));
+ memset(pc,0,DES_SUBKEY_LEN/8);
+ for(i=0;i<DES_SUBKEY_LEN;i++)
+  pc[i/8]|=((((key[subkey_perm_table[i]-1)/8]>>((8-subkey_perm_table[i]%8)&7))&1)<<(7-i%8));
+ return 1;
+}
 
- 
+int compute_subkeys(u8 *key0,u8 **subkey) {
+ int i;
+ key_perm(key0);
+ for(i=0;i<DES_SUBKEYS;i++) {
+  subkey_trans(key0;i);
+  subkey_perm(key0,subkey[i]);
+ }
  return 1;
 }
 
-int des_crypt(u8 *plain,u8 *crypted,u8 *key) {
- int round;
+int data_perm(u8 *plain,u8 *pd) {
+ int i;
+ memset(pd,0,DES_DATA_BLOCK_LEN/8);
+ for(i=0;i<DES_DATA_BLOCK_LEN;i++)
+  pd[i/8]|=((((plain[data_perm_table[i]-1)/8]>>((8-data_perm_table[i]%8)&7))&1)<<(7-i%8));
+ return 1;
+}
+
+int data_expansion_perm(u8 *right,u8 expanded) {
+ int i;
+ memset(expanded,0,DES_SUBKEY_LEN);
+ for(i=0;i<DES_SUBKEY_LEN;i++)
+  expanded[i/8]|=((((right[data_expansion_table[i]-1)/8]>>((8-data_expansion_table[i]%8)&7))&1)<<(7-i%8));
+ return 1;
+}
+
+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/2];
+ u8 p[DES_DATA_BLOCK_LEN/2];
+ int i,j;
+ 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);
+
+ return 1;
+}
+
+int progress_data(u8 *data,u8 **subkey,u8 mode) {
+ int i,j;
+ u8 pd[DES_DATA_BLOCK_LEN];
+ u8 left[DES_DATA_BLOCK_LEN/(2*8)];
+ u8 right[DES_DATA_BLOCK_LEN/(2*8)];
+ u8 expanded[DES_SUBKEY_LEN];
+
+ data_perm(data,pd);
+ memcpy(left,pd,DES_DATA_BLOCK_LEN/(2*8));
+ memcpy(right,pd+DES_DATA_BLOCK_LEN/(2*8),DES_DATA_BLOCK_LEN/(2*8));
+ for(i=0;i<DES_SUBKEYS;i++){
+  data_expansion_perm(right,expanded);
+  for(j=0;j<DES_SUBKEY_LEN;j++) expanded[j]^=subkey[mode&MODE_CRYPT?i:DES_SUBKEYS-1-i][j];
+  data_s_and_p(expanded);
 
- key_perm(key);
- for(round=0;round<DES_ROUND;round++) {
-  subkey_trans(key,round);
-  // fuckup_data(key,round,plain,crypted);
  }
+  
+ return 1;
+}
+
+int des_crypt_decrypt(u8 *plain,u8 *crypted,u8 *key,int len,u8 mode) {
+ u8 subkey[DES_SUBKEYS][DES_SUBKEY_LEN/8];
+ int i;
+
+ /* 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 all data do: (not yet ready) */
+ progress_data(plain,subkey,mode); 
 
  return 1;
 }
 
-int des_decrypt(u8 *crypted,u8 *plain,u8 *key) {
+int des_crypt(u8 *plain,u8 *crypted,u8 *key,int len,MODE_CRYPT) {
+
+ return 1;
+}
 
+int des_decrypt(u8 *crypted,u8 *plain,u8 *key,int len,MODE_DECRYPT) {
 
  return 1;
 }

diff --git a/des.h b/des.h
index ed1750c5e3bda1547981bd93f504e4223d6451bf..12da4556eb3e19c5db81bc5e7018dba10600cb1e 100644 (file)
--- a/des.h
+++ b/des.h
@@ -8,13 +8,22 @@
 #ifndef DES_H
 #define DES_H
 
-#define DES_ROUNDS 16
-#define DES_SUBKEY_LEN 56
-#define DES_PERMC_LEN 48
+#define DES_SUBKEYS 16
+#define DES_INITIAL_KEY_LEN 56
+#define DES_SUBKEY_LEN 48
+#define DES_DATA_BLOCK_LEN 64
+#define DES_SBOXES 8
+#define DES_SBOX_LEN 64
+#define DES_PBOX_LEN 32
+
+#define MODE_CRYPT 1
+#define MODE_DECRYPT 2
+#define MODE_ECB 4
+#define MODE_CBC 8
 
 typedef unsigned char u8;
 
-int des_encrypt(u8 *plain,u8 *crypted,u8 *key);
-int des_decrypt(u8 *crypted,u8 *plain,u8 *key);
+int des_encrypt(u8 *plain,u8 *crypted,u8 *key,int len,u8 mode);
+int des_decrypt(u8 *crypted,u8 *plain,u8 *key,int len,u8 mode);
 
 #endif /* DES_H */