OpenSSL des encryption and decryption

Recently in the collation of data encryption and decryption, integration of C/s,. NET, Java three platform data encryption and decryption materials, so that three platform invoke related functions to decrypt the results are consistent and compatible.

PS: The final collation of information may be issued in the form of electronic PDF, if it is beneficial to you, please pay attention to.

C + + is directly using the OpenSSL library Crypte module for data encryption and decryption, the following describes the Openssl/crypt call des for encryption and decryption process. The code is easy to understand and is directly attached to the code:

#include <stdio.h> #include "evp.h" #define BREAK_ERROR (msg) {\ fprintf (stderr, "ERROR break [%s]\n", msg); \

Break;\} #define CIPHER_INFO (e) {\ fprintf (stderr, "key_len:[%d]", Evp_cipher_ctx_key_length (e)); \ fprintf (stderr, "Iv_len: [%d ] ", Evp_cipher_ctx_iv_length (e)); \ fprintf (stderr," mode:[%d] ", Evp_cipher_ctx_mode (e)); \ fprintf (stderr," flag:[%d ")

\ n ", Evp_cipher_ctx_flags (e)); \} int Test_ecb_des (char *buf1,char *buf2,char *buf3,int *len1,int *len2,int *len3,unsigned char *key) {int ret = 0,tmple
    N 

    *len2 = *len3 = Tmplen = 0;
    /* Encrypt * * Evp_cipher_ctx CTX;
    Evp_cipher_ctx_init (&AMP;CTX);
    EVP_ENCRYPTINIT_EX (&AMP;CTX,EVP_DES_ECB (), null,key,null);
    Cipher_info (&AMP;CTX); do{if (!
    	Evp_encryptupdate (&AMP;CTX,BUF2,LEN2,BUF1,*LEN1)) {break_error ("encryptupdate"); } if (!
    	EVP_ENCRYPTFINAL_EX (&ctx,buf2+ (*len2), &tmplen)) {break_error ("encryptfinal");
    }}while (0);
    *len2 = *len2 + Tmplen; EVp_cipher_ctx_cleanup (&AMP;CTX);

    fprintf (stderr, "encrypt:len1:[%d] len2:[%d]\n", *len1,*len2);
    /* Decrypt * * Evp_cipher_ctx ctx_d;
    Evp_cipher_ctx_init (&ctx_d);
    EVP_DECRYPTINIT_EX (&AMP;CTX_D,EVP_DES_ECB (), null,key,null); do{if (!
    	Evp_decryptupdate (&ctx_d,buf3,len3,buf2,*len2)) {break_error ("decryptupdate"); } if (!
	Evp_decryptfinal (&ctx_d,buf3+ (*LEN3), &tmplen)) {break_error ("decryptfinal");
    }}while (0);
    *len3 = *len3 + Tmplen;
    Evp_cipher_ctx_cleanup (&ctx_d);
    fprintf (stderr, "encrypt:len2:[%d] len3:[%d]\n", *LEN2,*LEN3);
    /* Compare the data */if (memcmp (buf1,buf3,*len1) = = 0) {fprintf (stderr, "%s success\n", __func__);
    }else{fprintf (stderr, "%s failed\n", __func__);	
return 0;
    #define BUF_SIZE 102402 int main (int Argc,char * argv) {int i,len1,len2,len3;
    unsigned char key_8[] = {0,1,2,3,4,5,6,7};
    unsigned char iv_8[] = {7,6,5,4,3,2,1,0}; char * buf1 = (char *) malloc (buf_size+ 1);
    char * buf2 = (char *) malloc (buf_size + 1);
    char * buf3 = (char *) malloc (buf_size + 1);
    Len1 = Len2 = Len3 = Buf_size;
    for (i = 0;i< buf_size;i++) {buf1[i] = i%256;

    } test_ecb_des (Buf1,buf2,buf3,&len1,&len2,&len3,key_8);
return 0; I/////////////////////////////////////////////////////////////////// One thing I have to say is that des has been deciphered, and of course the cost of deciphering it is not low, and not so simple. If you require a higher level of data security, you can choose to use 3DES or AES, and so on.

The above code is run under the  OPENSSL-0.9.8ZD version and passed the test. Not sure if you can run it on all versions of OpenSSL. In use is please test.