Commit dd2bf9eb authored by Daniel P. Berrangé's avatar Daniel P. Berrangé
Browse files

crypto: add additional query accessors for cipher instances 



Adds new methods to allow querying the length of the cipher
key, block size and initialization vectors.

Reviewed-by: default avatarEric Blake <eblake@redhat.com>
Signed-off-by: default avatarDaniel P. Berrange <berrange@redhat.com>
parent 5dc42c18

crypto/cipher.c

+48 −0
Original line number Diff line number Diff line
@@ -28,6 +28,54 @@ static size_t alg_key_len[QCRYPTO_CIPHER_ALG_LAST] = { 
    [QCRYPTO_CIPHER_ALG_DES_RFB] = 8,

};



static size_t alg_block_len[QCRYPTO_CIPHER_ALG_LAST] = {

    [QCRYPTO_CIPHER_ALG_AES_128] = 16,

    [QCRYPTO_CIPHER_ALG_AES_192] = 16,

    [QCRYPTO_CIPHER_ALG_AES_256] = 16,

    [QCRYPTO_CIPHER_ALG_DES_RFB] = 8,

};



static bool mode_need_iv[QCRYPTO_CIPHER_MODE_LAST] = {

    [QCRYPTO_CIPHER_MODE_ECB] = false,

    [QCRYPTO_CIPHER_MODE_CBC] = true,

};





size_t qcrypto_cipher_get_block_len(QCryptoCipherAlgorithm alg)

{

    if (alg >= G_N_ELEMENTS(alg_key_len)) {

        return 0;

    }

    return alg_block_len[alg];

}





size_t qcrypto_cipher_get_key_len(QCryptoCipherAlgorithm alg)

{

    if (alg >= G_N_ELEMENTS(alg_key_len)) {

        return 0;

    }

    return alg_key_len[alg];

}





size_t qcrypto_cipher_get_iv_len(QCryptoCipherAlgorithm alg,

                                 QCryptoCipherMode mode)

{

    if (alg >= G_N_ELEMENTS(alg_block_len)) {

        return 0;

    }

    if (mode >= G_N_ELEMENTS(mode_need_iv)) {

        return 0;

    }



    if (mode_need_iv[mode]) {

        return alg_block_len[alg];

    }

    return 0;

}





static bool

qcrypto_cipher_validate_key_length(QCryptoCipherAlgorithm alg,

                                   size_t nkey,

include/crypto/cipher.h

+37 −0
Original line number Diff line number Diff line
@@ -107,6 +107,43 @@ struct QCryptoCipher { 
 */

bool qcrypto_cipher_supports(QCryptoCipherAlgorithm alg);



/**

 * qcrypto_cipher_get_block_len:

 * @alg: the cipher algorithm

 *

 * Get the required data block size in bytes. When

 * encrypting data, it must be a multiple of the

 * block size.

 *

 * Returns: the block size in bytes

 */

size_t qcrypto_cipher_get_block_len(QCryptoCipherAlgorithm alg);





/**

 * qcrypto_cipher_get_key_len:

 * @alg: the cipher algorithm

 *

 * Get the required key size in bytes.

 *

 * Returns: the key size in bytes

 */

size_t qcrypto_cipher_get_key_len(QCryptoCipherAlgorithm alg);





/**

 * qcrypto_cipher_get_iv_len:

 * @alg: the cipher algorithm

 * @mode: the cipher mode

 *

 * Get the required initialization vector size

 * in bytes, if one is required.

 *

 * Returns: the IV size in bytes, or 0 if no IV is permitted

 */

size_t qcrypto_cipher_get_iv_len(QCryptoCipherAlgorithm alg,

                                 QCryptoCipherMode mode);





/**

 * qcrypto_cipher_new:

tests/test-crypto-cipher.c

+10 −0
Original line number Diff line number Diff line
@@ -229,6 +229,7 @@ static void test_cipher(const void *opaque) 
    uint8_t *key, *iv, *ciphertext, *plaintext, *outtext;

    size_t nkey, niv, nciphertext, nplaintext;

    char *outtexthex;

    size_t ivsize, keysize, blocksize;



    nkey = unhex_string(data->key, &key);

    niv = unhex_string(data->iv, &iv);
@@ -245,6 +246,15 @@ static void test_cipher(const void *opaque) 
        &error_abort);

    g_assert(cipher != NULL);



    keysize = qcrypto_cipher_get_key_len(data->alg);

    blocksize = qcrypto_cipher_get_block_len(data->alg);

    ivsize = qcrypto_cipher_get_iv_len(data->alg, data->mode);



    g_assert_cmpint(keysize, ==, nkey);

    g_assert_cmpint(ivsize, ==, niv);

    if (niv) {

        g_assert_cmpint(blocksize, ==, niv);

    }



    if (iv) {

        g_assert(qcrypto_cipher_setiv(cipher,