Ejemplo n.º 1
0
QCryptoCipher *qcrypto_cipher_new(QCryptoCipherAlgorithm alg,
                                  QCryptoCipherMode mode,
                                  const uint8_t *key, size_t nkey,
                                  Error **errp)
{
    QCryptoCipher *cipher;
    gcry_cipher_hd_t handle;
    gcry_error_t err;
    int gcryalg, gcrymode;

    switch (mode) {
    case QCRYPTO_CIPHER_MODE_ECB:
        gcrymode = GCRY_CIPHER_MODE_ECB;
        break;
    case QCRYPTO_CIPHER_MODE_CBC:
        gcrymode = GCRY_CIPHER_MODE_CBC;
        break;
    default:
        error_setg(errp, "Unsupported cipher mode %d", mode);
        return NULL;
    }

    if (!qcrypto_cipher_validate_key_length(alg, nkey, errp)) {
        return NULL;
    }

    switch (alg) {
    case QCRYPTO_CIPHER_ALG_DES_RFB:
        gcryalg = GCRY_CIPHER_DES;
        break;

    case QCRYPTO_CIPHER_ALG_AES_128:
        gcryalg = GCRY_CIPHER_AES128;
        break;

    case QCRYPTO_CIPHER_ALG_AES_192:
        gcryalg = GCRY_CIPHER_AES192;
        break;

    case QCRYPTO_CIPHER_ALG_AES_256:
        gcryalg = GCRY_CIPHER_AES256;
        break;

    default:
        error_setg(errp, "Unsupported cipher algorithm %d", alg);
        return NULL;
    }

    cipher = g_new0(QCryptoCipher, 1);
    cipher->alg = alg;
    cipher->mode = mode;

    err = gcry_cipher_open(&handle, gcryalg, gcrymode, 0);
    if (err != 0) {
        error_setg(errp, "Cannot initialize cipher: %s",
                   gcry_strerror(err));
        goto error;
    }

    if (cipher->alg == QCRYPTO_CIPHER_ALG_DES_RFB) {
        /* We're using standard DES cipher from gcrypt, so we need
         * to munge the key so that the results are the same as the
         * bizarre RFB variant of DES :-)
         */
        uint8_t *rfbkey = qcrypto_cipher_munge_des_rfb_key(key, nkey);
        err = gcry_cipher_setkey(handle, rfbkey, nkey);
        g_free(rfbkey);
    } else {
        err = gcry_cipher_setkey(handle, key, nkey);
    }
    if (err != 0) {
        error_setg(errp, "Cannot set key: %s",
                   gcry_strerror(err));
        goto error;
    }

    cipher->opaque = handle;
    return cipher;

 error:
    gcry_cipher_close(handle);
    g_free(cipher);
    return NULL;
}
Ejemplo n.º 2
0
QCryptoCipher *qcrypto_cipher_new(QCryptoCipherAlgorithm alg,
                                  QCryptoCipherMode mode,
                                  const uint8_t *key, size_t nkey,
                                  Error **errp)
{
    QCryptoCipher *cipher;
    QCryptoCipherNettle *ctx;
    uint8_t *rfbkey;

    switch (mode) {
    case QCRYPTO_CIPHER_MODE_ECB:
    case QCRYPTO_CIPHER_MODE_CBC:
        break;
    default:
        error_setg(errp, "Unsupported cipher mode %d", mode);
        return NULL;
    }

    if (!qcrypto_cipher_validate_key_length(alg, nkey, errp)) {
        return NULL;
    }

    cipher = g_new0(QCryptoCipher, 1);
    cipher->alg = alg;
    cipher->mode = mode;

    ctx = g_new0(QCryptoCipherNettle, 1);

    switch (alg) {
    case QCRYPTO_CIPHER_ALG_DES_RFB:
        ctx->ctx_encrypt = g_new0(struct des_ctx, 1);
        ctx->ctx_decrypt = NULL; /* 1 ctx can do both */
        rfbkey = qcrypto_cipher_munge_des_rfb_key(key, nkey);
        des_set_key(ctx->ctx_encrypt, rfbkey);
        g_free(rfbkey);

        ctx->alg_encrypt = des_encrypt_wrapper;
        ctx->alg_decrypt = des_decrypt_wrapper;

        ctx->blocksize = DES_BLOCK_SIZE;
        break;

    case QCRYPTO_CIPHER_ALG_AES_128:
    case QCRYPTO_CIPHER_ALG_AES_192:
    case QCRYPTO_CIPHER_ALG_AES_256:
        ctx->ctx_encrypt = g_new0(struct aes_ctx, 1);
        ctx->ctx_decrypt = g_new0(struct aes_ctx, 1);

        aes_set_encrypt_key(ctx->ctx_encrypt, nkey, key);
        aes_set_decrypt_key(ctx->ctx_decrypt, nkey, key);

        ctx->alg_encrypt = aes_encrypt_wrapper;
        ctx->alg_decrypt = aes_decrypt_wrapper;

        ctx->blocksize = AES_BLOCK_SIZE;
        break;
    default:
        error_setg(errp, "Unsupported cipher algorithm %d", alg);
        goto error;
    }

    ctx->iv = g_new0(uint8_t, ctx->blocksize);
    cipher->opaque = ctx;

    return cipher;

 error:
    g_free(cipher);
    g_free(ctx);
    return NULL;
}