rust-openssl-40.c

#include <stdio.h>
#include <openssl/evp.h>

int main(void) {
  unsigned char plaintext[] = "AAAAAAAAAAAAAAAA";
  unsigned char key[] = "BBBBBBBBBBBBBBBB";
  unsigned char iv[] = "\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0\0";
  unsigned char res[32];

  // Encrypting
  // ----------
  printf("ENCRYPTING\n\n");

  EVP_CIPHER_CTX * ctx = EVP_CIPHER_CTX_new();
  const EVP_CIPHER * evp = EVP_aes_128_ecb();

  EVP_CIPHER_CTX_set_padding(ctx, 0);

  EVP_CipherInit(ctx, evp, key, iv, 1);

  int reslen = 32;
  EVP_CipherUpdate(ctx, res, &reslen, plaintext, 16);

  unsigned char res_final[16];
  int reslen_final = 16;
  EVP_CipherFinal(ctx, res_final, &reslen_final);

  printf("reslen = %d\nres: ", reslen);
  int i;
  for (i = 0; i < 32; i++) {
    printf("%02x ", res[i]);
  }
  printf("\n\n");

  printf("reslen_final = %d\nres_final: ", reslen_final);
  for (i = 0; i < 16; i++) {
    printf("%02x ", res_final[i]);
  }
  printf("\n\n\n");

  // Decrypting
  // ----------
  printf("DECRYPTING\n\n");

  ctx = EVP_CIPHER_CTX_new();
  EVP_CIPHER_CTX_set_padding(ctx, 0);
  EVP_CipherInit(ctx, evp, key, iv, 0);

  unsigned char resd[32];
  reslen = 32;
  EVP_CipherUpdate(ctx, resd, &reslen, res, 16);

  unsigned char resd_final[16];
  reslen_final = 16;
  EVP_CipherFinal(ctx, resd_final, &reslen_final);

  printf("reslen = %d\nresd: ", reslen);
  for (i = 0; i < 32; i++) {
    printf("%02x ", resd[i]);
  }
  printf("\n\n");

  printf("reslen_final = %d\nresd_final: ", reslen_final);
  for (i = 0; i < 16; i++) {
    printf("%02x ", resd_final[i]);
  }
  printf("\n");

  return 0;
}

Output:

ENCRYPTING

reslen = 16
res: 12 66 73 34 44 73 0c b9 c5 84 a2 e9 bf 3f 73 52 2e 4e 3d f6 00 00 00 00 7d 05 40 00 00 00 00 00 

reslen_final = 16
res_final: 26 08 03 68 4c d0 fa d7 9c e8 f6 91 19 e4 5b 54 


DECRYPTING

reslen = 0
resd: 41 41 41 41 41 41 41 41 41 41 41 41 41 41 41 41 01 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 

reslen_final = 0
resd_final: 00 00 00 00 00 00 00 00 6f 8a 74 31 ea 7f 00 00