Re: [PATCH v4 2/3] drivers: crypto: Add the Virtual Function driver for CPT

Hi Stephan,

Thanks for pointing it out!!


On 01/11/2017 04:42 PM, Stephan Müller wrote:

Am Mittwoch, 11. Januar 2017, 10:56:50 CET schrieb George Cherian:

Hi George,

quoted

+int cvm_enc_dec_setkey(struct crypto_ablkcipher *cipher, const u8 *key,
+		       u32 keylen)
+{
+	struct crypto_tfm *tfm = crypto_ablkcipher_tfm(cipher);
+	struct cvm_enc_ctx *ctx = crypto_tfm_ctx(tfm);
+
+	if ((keylen == 16) || (keylen == 24) || (keylen == 32)) {
+		ctx->key_len = keylen;
+		memcpy(ctx->enc_key, key, keylen);
+		return 0;
+	}
+	crypto_ablkcipher_set_flags(cipher, CRYPTO_TFM_RES_BAD_KEY_LEN);
+
+	return -EINVAL;
+}

I will add a seperate function for xts setkey and make changes as following.

...

quoted

+
+struct crypto_alg algs[] = { {
+	.cra_flags = CRYPTO_ALG_TYPE_ABLKCIPHER | CRYPTO_ALG_ASYNC,
+	.cra_blocksize = AES_BLOCK_SIZE,
+	.cra_ctxsize = sizeof(struct cvm_enc_ctx),
+	.cra_alignmask = 7,
+	.cra_priority = 4001,
+	.cra_name = "xts(aes)",
+	.cra_driver_name = "cavium-xts-aes",
+	.cra_type = &crypto_ablkcipher_type,
+	.cra_u = {
+		.ablkcipher = {
+			.ivsize = AES_BLOCK_SIZE,
+			.min_keysize = AES_MIN_KEY_SIZE,
+			.max_keysize = AES_MAX_KEY_SIZE,
+			.setkey = cvm_enc_dec_setkey,

May I ask how the setkey for XTS is intended to work? The XTS keys are double
in size than "normal" keys.

		.ablkcipher = {
			.ivsize = AES_BLOCK_SIZE,
			.min_keysize = 2 * AES_MIN_KEY_SIZE,
			.max_keysize = 2 * AES_MAX_KEY_SIZE,
			.setkey = cvm_xts_setkey,

Hope this is fine?

quoted

+			.encrypt = cvm_aes_encrypt_xts,
+			.decrypt = cvm_aes_decrypt_xts,
+		},

Ciao
Stephan

Regards,
-George