You need to use same iv and key for decryption.
I believe the command is
openssl enc -d -aes-256-cbc -K <key used to encrypt> -iv <iv used to
encrypt> -in rgconf_encrypted -out rgconf_decrypted.
-Anand
On Tue, May 25, 2010 at 8:30 AM, ~ Kunal Sharma ~ <koolku...@gmail.com>wrote:
> Friends,
>
> I'm trying to verify that my encryption and decryption routines work ok.
> One way I do it is to encrypt the data and save it to a file. The I feed the
> encrypted file to my decryption routine and write the decrypted data to
> another file. I compare the original data and the contents of the decrypted
> file and they are same. So the routines work fine in tandem.
>
> Another method I want to use it to encrypt the data and save it to a file.
> Then I feed the encrypted file to Openssl command line to decrypt.
>
> I get my encrypted data in the file rgconf_encrypted. Then I run the
> following command:
>
> openssl enc -d -aes-256-cbc -in rgconf_encrypted
>
> I enter the decryption password "As different as chalk and cheese" which I
> used to encrypt the data. But I get the error "bad magic number".
>
> Am I missing something here ? I need to be able to use a simple phrase as
> my encryption password so I can decrypt it on command line as well. Please
> provide any pointers on what could be wrong here.
>
> Below is the code for my encryption routine.
>
> Thanks,
> Kunal
>
> ++++++++++++++++++++++++++++++++++++++++++
> int encrypt(void)
> {
> EVP_CIPHER_CTX ctx;
> unsigned char ibuf[1024],obuf[1024];
> int rfd, wfd,ilen,olen,tlen;
>
> unsigned char key32[] = "As different as chalk and cheese";
> unsigned char iv[] = "As dark as pitch";
> EVP_CIPHER_CTX_init(&ctx);
> if(!EVP_CipherInit_ex(&ctx, EVP_aes_256_cbc(),NULL,key32, iv,AES_ENCRYPT)
> ) {
> console_printf("Couldnt initialize cipher\n");
> return 1;
> }
> /* read the original contents that are stored in file /etc/rgconf */
> if((rfd = open("/etc/rgconf",O_RDONLY) ) == -1) {
> console_printf("Couldnt open input file\n");
> return 1;
> }
>
> /* open a file /et.rgconf_encrypted to store encrypted data */
> if((wfd = creat("/etc/rgconf_encrypted",0644) ) == -1) {
> console_printf("Couldn't open output file for writing\n");
> return 1;
> }
> while((ilen = read(rfd,ibuf,1024) ) > 0) {
> if(EVP_CipherUpdate(&ctx,obuf,&olen,ibuf,ilen)){
> write(wfd,obuf,olen);
> }
> else {
> console_printf("Encryption error\n");
> return 1;
> }
> }
> if(!EVP_CipherFinal_ex(&ctx,obuf+olen,&tlen)) {
> console_printf("Trouble with padding the last block\n");
> return 1;
> }
>
> write(wfd,obuf+olen,tlen);
> EVP_CIPHER_CTX_cleanup(&ctx);
> close(rfd);
> close(wfd);
> console_printf("AES 256 CBC encryption complete\n");
> return 0;
> }
> ++++++++++++++++++++++++++++++++++++++++++
>
>
>
>
>
