Commit 981d0a24 authored by Nick Mathewson's avatar Nick Mathewson 🦀
Browse files

In aes.c, support 192-bit and 256-bit keys. 

Also, change the input types for aes_new_cipher to be unsigned,
as they should have been all along.
parent b08ddb60

src/common/aes.c

+17 −9
Original line number Diff line number Diff line
@@ -89,11 +89,17 @@ ENABLE_GCC_WARNING(redundant-decls) 
/* We don't actually define the struct here. */



aes_cnt_cipher_t *

aes_new_cipher(const char *key, const char *iv)

aes_new_cipher(const uint8_t *key, const uint8_t *iv, int key_bits)

{

  EVP_CIPHER_CTX *cipher = EVP_CIPHER_CTX_new();

  EVP_EncryptInit(cipher, EVP_aes_128_ctr(),

                  (const unsigned char*)key, (const unsigned char *)iv);

  const EVP_CIPHER *c;

  switch (key_bits) {

    case 128: c = EVP_aes_128_ctr(); break;

    case 192: c = EVP_aes_192_ctr(); break;

    case 256: c = EVP_aes_256_ctr(); break;

    default: tor_assert(0); // LCOV_EXCL_LINE

  }

  EVP_EncryptInit(cipher, c, key, iv);

  return (aes_cnt_cipher_t *) cipher;

}

void
@@ -262,11 +268,11 @@ static void aes_set_iv(aes_cnt_cipher_t *cipher, const char *iv); 
 * using the 128-bit key <b>key</b> and the 128-bit IV <b>iv</b>.

 */

aes_cnt_cipher_t*

aes_new_cipher(const char *key, const char *iv)

aes_new_cipher(const uint8_t *key, const uint8_t *iv, int bits)

{

  aes_cnt_cipher_t* result = tor_malloc_zero(sizeof(aes_cnt_cipher_t));



  aes_set_key(result, key, 128);

  aes_set_key(result, key, bits);

  aes_set_iv(result, iv);



  return result;
@@ -277,7 +283,7 @@ aes_new_cipher(const char *key, const char *iv) 
 * the counter to 0.

 */

static void

aes_set_key(aes_cnt_cipher_t *cipher, const char *key, int key_bits)

aes_set_key(aes_cnt_cipher_t *cipher, const uint8_t *key, int key_bits)

{

  if (should_use_EVP) {

    const EVP_CIPHER *c = 0;
@@ -287,10 +293,10 @@ aes_set_key(aes_cnt_cipher_t *cipher, const char *key, int key_bits) 
      case 256: c = EVP_aes_256_ecb(); break;

      default: tor_assert(0); // LCOV_EXCL_LINE

    }

    EVP_EncryptInit(&cipher->key.evp, c, (const unsigned char*)key, NULL);

    EVP_EncryptInit(&cipher->key.evp, c, key, NULL);

    cipher->using_evp = 1;

  } else {

    AES_set_encrypt_key((const unsigned char *)key, key_bits,&cipher->key.aes);

    AES_set_encrypt_key(key, key_bits,&cipher->key.aes);

    cipher->using_evp = 0;

  }
@@ -348,6 +354,8 @@ evp_block128_fn(const uint8_t in[16], 
void

aes_crypt_inplace(aes_cnt_cipher_t *cipher, char *data, size_t len)

{

  /* Note that the "128" below refers to the length of the counter,

   * not the length of the AES key. */

  if (cipher->using_evp) {

    /* In openssl 1.0.0, there's an if'd out EVP_aes_128_ctr in evp.h.  If

     * it weren't disabled, it might be better just to use that.
@@ -374,7 +382,7 @@ aes_crypt_inplace(aes_cnt_cipher_t *cipher, char *data, size_t len) 
/** Reset the 128-bit counter of <b>cipher</b> to the 16-bit big-endian value

 * in <b>iv</b>. */

static void

aes_set_iv(aes_cnt_cipher_t *cipher, const char *iv)

aes_set_iv(aes_cnt_cipher_t *cipher, const uint8_t *iv)

{

#ifdef USING_COUNTER_VARS

  cipher->counter3 = ntohl(get_uint32(iv));

src/common/aes.h

+2 −1
Original line number Diff line number Diff line
@@ -15,7 +15,8 @@ 


typedef struct aes_cnt_cipher aes_cnt_cipher_t;



aes_cnt_cipher_t* aes_new_cipher(const char *key, const char *iv);

aes_cnt_cipher_t* aes_new_cipher(const uint8_t *key, const uint8_t *iv,

                                 int key_bits);

void aes_cipher_free(aes_cnt_cipher_t *cipher);

void aes_crypt_inplace(aes_cnt_cipher_t *cipher, char *data, size_t len);

src/common/crypto.c

+7 −6
Original line number Diff line number Diff line
@@ -69,6 +69,7 @@ ENABLE_GCC_WARNING(redundant-decls) 
#endif



#include "torlog.h"

#include "torint.h"

#include "aes.h"

#include "util.h"

#include "container.h"
@@ -122,8 +123,8 @@ struct crypto_pk_t 
/** Key and stream information for a stream cipher. */

struct crypto_cipher_t

{

  char key[CIPHER_KEY_LEN]; /**< The raw key. */

  char iv[CIPHER_IV_LEN]; /**< The initial IV. */

  uint8_t key[CIPHER_KEY_LEN]; /**< The raw key. */

  uint8_t iv[CIPHER_IV_LEN]; /**< The initial IV. */

  aes_cnt_cipher_t *cipher; /**< The key in format usable for counter-mode AES

                             * encryption */

};
@@ -561,15 +562,15 @@ crypto_cipher_new_with_iv(const char *key, const char *iv) 
  env = tor_malloc_zero(sizeof(crypto_cipher_t));



  if (key == NULL)

    crypto_rand(env->key, CIPHER_KEY_LEN);

    crypto_rand((char*)env->key, CIPHER_KEY_LEN);

  else

    memcpy(env->key, key, CIPHER_KEY_LEN);

  if (iv == NULL)

    crypto_rand(env->iv, CIPHER_IV_LEN);

    crypto_rand((char*)env->iv, CIPHER_IV_LEN);

  else

    memcpy(env->iv, iv, CIPHER_IV_LEN);



  env->cipher = aes_new_cipher(env->key, env->iv);

  env->cipher = aes_new_cipher(env->key, env->iv, 128);



  return env;

}
@@ -1587,7 +1588,7 @@ crypto_pk_base64_decode(const char *str, size_t len) 
const char *

crypto_cipher_get_key(crypto_cipher_t *env)

{

  return env->key;

  return (const char *)env->key;

}



/** Encrypt <b>fromlen</b> bytes from <b>from</b> using the cipher