Thread: 3DES ECB MODE IN OPENSSL Can't get expected Result

Hi All,

I am using the OPENSSL to encrypt the plain text, but the output is wrong, can anyone give me hints or solution, many thanks!!

Code:

unsigned char out[8];
    char back[bufsize],workvec[bufsize];
    const char *temp="
0592789FFFEDCBA9
";
    
    des_cblock key1,key3,seed = {0x13,0x13,0x23,0x23,0x23,0x23,0x13,0x13};
    des_cblock key2 =           {0x67,0x89,0x67,0x89,0x67,0x89,0x67,0x89};
    
    des_key_schedule ks1,ks2,ks3;
    
    char master1c[8];
    char c1[16];
    int length = strlen(temp);
    int i;
    char buf = 0;
    int z=0;
    for(i = 0; i < length; i++){
        if(i % 2 != 0){
//change hex to ascii
            sprintf(master1c+z, "%c", hex_to_ascii(buf, c1[i]));
            z++;
        }else{
            buf = c1[i];
        }
    }
    char *in =master1c;


    
    DES_set_key((C_Block *)_k1,&ks1);
    DES_set_key((C_Block *)_k2,&ks2);
    DES_set_key((C_Block *)_k3,&ks3);
    
    DES_ecb3_encrypt((C_Block *)in,out,&ks1,&ks2,&ks3, DES_ENCRYPT);


    for (i=0; i<8; i++)
    {
        printf("0x%02X, ", out[i]);
    }

My Wrong Result=0xAD, 0x62, 0xDC, 0x19, 0xBB, 0xFE, 0x61, 0x52

Expected Result=0x

90, 0xDE, 0xBD, 0x82, 0x7C, 0xEE, 0x4F, 0xDD

How are we supposed to work anything out when half the code and declarations are missing?

What is hex_to_ascii(), does it get the byte the right way round?

What are _k1 etc?

You can simplify the sprintf to
master1c[z] = hex_to_ascii(buf, c1[i]);

Hi, whole code as below, _k1,_k2, _k3 change to key1, key2, key3
please give me some hints, many thanks!!

Code:

unsigned char out[8];    
const char *temp="0592789FFFEDCBA9";
 des_cblock key1,key3,seed = {0x13,0x13,0x23,0x23,0x23,0x23,0x13,0x13};   
 des_cblock key2 =           {0x67,0x89,0x67,0x89,0x67,0x89,0x67,0x89};        
des_key_schedule ks1,ks2,ks3;
char master1c[8];    
char c1[16];
    int length = strlen(temp); 
   int i;
    char buf = 0;  
  int z=0;
    for(i = 0; i < length; i++)
    {
        if(i % 2 != 0)
       {
             //change hex to ascii            
             sprintf(master1c+z, "%c", hex_to_ascii(buf, c1[i])); 
           z++;        
       }else
       {            
             buf = c1[i];        
        }    
    }    
    char *in =master1c;
    DES_set_key((C_Block *)key1,&ks1);
     DES_set_key((C_Block *)key2,&ks2);
    DES_set_key((C_Block *)key3,&ks3);
        DES_ecb3_encrypt((C_Block *)in,out,&ks1,&ks2,&ks3, DES_ENCRYPT);    

     for (i=0; i<8; i++)    
    {        
           printf("0x%02X, ", out[i]);    
    }

Code:

int hex_to_int(char c){
    if(c>=97)
        c=c-32;
    int first = c / 16 - 3;
    int second = c % 16;
    int result = first*10 + second;
    if(result > 9) result--;
    return result;
}


int hex_to_ascii(char c, char d){
    int high = hex_to_int(c) * 16;
    int low = hex_to_int(d);
    return high+low;
}

Where do you set key1 and key3 to a valid value?

Tim S.

Originally Posted by homoon

Here is the key valuekey1, key3= 1313232323231313key2 = 6789678967896789===============================

Code:

des_cblock key1,key3,seed = {0x13,0x13,0x23,0x23,0x23,0x23,0x13,0x13};   des_cblock key2 =           {0x67,0x89,0x67,0x89,0x67,0x89,0x67,0x89};

I see you setting the seed to a value; NO WHERE are you setting key1 or key3 to a initial value in the code posted!!

Tim S.

Code:

#include <stdio.h>
#include <stdlib.h>

int main()
{
    typedef des_cblock[8];
    int i;

    des_cblock key1,key3,seed = {0x13,0x13,0x23,0x23,0x23,0x23,0x13,0x13};
    des_cblock key2 =           {0x67,0x89,0x67,0x89,0x67,0x89,0x67,0x89};

    for (i=0; i< 8; i++)
    {
        printf("%d\n", seed[i]);
    }

    for (i=0; i< 8; i++)
    {
        printf("%d\n", key1[i]); // Prints out garbage values
    }

    return 0;
}

Originally Posted by homoon

I want to ask a question, the plain text pass in to the

DES_ecb3_encrypt function, is it a "hex string"? or I need to change it to ascii code?

I have no idea; I suggest reading the documentation or looking for example usage.

Tim S.

Code:

printf("10 hex:= %d dec\n", hex_to_int("10"));

Any reason you function hex_to_int() only returns the value of 5 for any of the input I tested it with?

Tim S.

This is an example of code that can be compiled; you are really more likely to get help. When you post a short but complete program. Or at least a complete function.

FYI: You helper functions are junk; you need to document them and test them.

Code:

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include "openssl/des.h"

int main() {

    unsigned char out[8]={0};
    des_cblock key1 = {0x13,0x13,0x23,0x23,0x23,0x23,0x13,0x13};
    des_cblock key3 = {0x13,0x13,0x23,0x23,0x23,0x23,0x13,0x13};
    des_cblock key2 = {0x67,0x89,0x67,0x89,0x67,0x89,0x67,0x89};
    des_key_schedule ks1,ks2,ks3;
    unsigned char in[8]= {0x05, 0x92, 0x78, 0x9F, 0xFF, 0xED, 0xCB, 0xA9};
    int i=0;

    DES_set_key((C_Block *)key1,&ks1);
    DES_set_key((C_Block *)key2,&ks2);
    DES_set_key((C_Block *)key3,&ks3);

    for (i=0; i<7; i++) {
        printf("0x%02X, ", in[i]);
    }
    printf("0x%02X\n", in[i]);

    DES_ecb3_encrypt((C_Block *)in,(C_Block *)out,&ks1,&ks2,&ks3, DES_ENCRYPT);

    for (i=0; i<7; i++) {
        printf("0x%02X, ", out[i]);
    }
    printf("0x%02X\n", out[i]);

    return 0;
}

My output.

Code:

0x05, 0x92, 0x78, 0x9F, 0xFF, 0xED, 0xCB, 0xA9
0x90, 0xDE, 0xBD, 0x82, 0x7C, 0xEE, 0x4F, 0xDD