Hi Peter,
Add padding for CBC mode encryption.
Or u can use CFB mode. EVB_bf_cfb()
-Shafeek
On Sat, Apr 30, 2011 at 7:26 PM, derleader mail <derlea...@abv.bg> wrote:
> Hi,
> I have a problem with the code below. There is a bug that I can't find
> and fix.
> This is the output when I try to run it:
>
> [root@localhost test]# ./a.out sdcsdsdcd
> Entering Encryption Stage:
>
> String to encrypt: sdcsdsdcd
>
> Encryption Successful
>
> Entering Decryption Stage
>
> Error Whilst DecryptFinal
> 19041:error:06065064:lib(6):func(101):reason(100):evp_enc.c:325:
>
>
> Here is the source code:
>
>
>
> #include <stdio.h>
> #include <stdlib.h>
> #include <string.h>
> #include <openssl/evp.h>
> #include <openssl/rand.h>
>
> #define input_buf_size 1024
> #define output_buf_size 1032
>
> int main(int argc, char *argv[])
> {
>
> if (argc !=2)
> {
> printf("Usage: test1 <stringtoencrypt>\n");
> exit(1);
> }
>
> char *string;
>
> int encoutlen, decoutlen, enctotallen, dectotallen;
>
> unsigned char iv[8];
> unsigned char password[16];
> unsigned char enc_outbuf[output_buf_size];
> char enc_inbuf[input_buf_size];
> unsigned char dec_outbuf[input_buf_size];
> char dec_inbuf[output_buf_size];
> EVP_CIPHER_CTX ectx;
> EVP_CIPHER_CTX dctx;
>
> /*
> * Begin the encode - decode
> *
> * Get our inputs and the random IV
> *
> */
>
> string = argv[1];
>
> RAND_bytes(iv, 8);
> RAND_bytes(password, 16);
>
> printf("Entering Encryption Stage:\n\n");
> printf("String to encrypt: %s\n\n", string);
>
> EVP_CIPHER_CTX_init(&ectx);
>
>
> EVP_EncryptInit(&ectx, EVP_bf_cbc(), password, iv);
>
> bzero (&enc_inbuf, input_buf_size);
>
> if(!EVP_EncryptUpdate(&ectx, enc_outbuf, &encoutlen, string,
> strlen(string)))
> {
> printf("Error whilst EncryptUpdate\n");
> return 0;
> }
>
> if(!EVP_EncryptFinal(&ectx, enc_outbuf + encoutlen, &enctotallen))
> {
> printf("Error Whilst EncryptFinal\n");
> return 0;
> }
>
> encoutlen += enctotallen;
>
> printf("Encryption Successful\n\n");
> printf("Entering Decryption Stage\n\n");
>
> EVP_CIPHER_CTX_init(&dctx);
> EVP_DecryptInit(&dctx, EVP_bf_cbc(), password, iv);
>
> bzero (&dec_inbuf, output_buf_size);
> bzero (&dec_outbuf, input_buf_size);
>
> if (!(EVP_DecryptUpdate(&dctx, dec_outbuf, &decoutlen, enc_outbuf,
> output_buf_size)))
> {
> printf("Error Whilst DecryptUpdate\n");
> return 0;
> }
>
> if (!(EVP_DecryptFinal(&dctx, dec_outbuf + decoutlen,
> &dectotallen)))
> {
> printf("Error Whilst DecryptFinal\n");
> ERR_print_errors_fp(stdout);
> return 0;
> }
>
> decoutlen += dectotallen;
>
> printf("Decryption Successful\n\n");
>
> printf("Decrypted String is: %s\n", dec_outbuf);
>
> return 0;
>
> }
>
> Any help will be highly appreciated!
>
> Regards
> Peter
>
