KEYS: asym_tpm: Implement encryption operation [ver #2] (ad4b1eb5) · Commits · 戴 / test

crypto/asymmetric_keys/asym_tpm.c

+84 −0

Original line number	Diff line number	Diff line
		@@ -165,6 +165,8 @@ static int tpm_key_query(const struct kernel_pkey_params *params,
		info->max_enc_size = len;
		info->max_dec_size = tk->key_len / 8;

		info->supported_ops = KEYCTL_SUPPORTS_ENCRYPT;

		ret = 0;
		error_free_tfm:
		crypto_free_akcipher(tfm);
		@@ -172,6 +174,87 @@ error_free_tfm:
		return ret;
		}

		/*
		* Encryption operation is performed with the public key. Hence it is done
		* in software
		*/
		static int tpm_key_encrypt(struct tpm_key *tk,
		struct kernel_pkey_params *params,
		const void in, void out)
		{
		char alg_name[CRYPTO_MAX_ALG_NAME];
		struct crypto_akcipher *tfm;
		struct akcipher_request *req;
		struct crypto_wait cwait;
		struct scatterlist in_sg, out_sg;
		uint8_t der_pub_key[PUB_KEY_BUF_SIZE];
		uint32_t der_pub_key_len;
		int ret;

		pr_devel("==>%s()\n", __func__);

		ret = determine_akcipher(params->encoding, params->hash_algo, alg_name);
		if (ret < 0)
		return ret;

		tfm = crypto_alloc_akcipher(alg_name, 0, 0);
		if (IS_ERR(tfm))
		return PTR_ERR(tfm);

		der_pub_key_len = derive_pub_key(tk->pub_key, tk->pub_key_len,
		der_pub_key);

		ret = crypto_akcipher_set_pub_key(tfm, der_pub_key, der_pub_key_len);
		if (ret < 0)
		goto error_free_tfm;

		req = akcipher_request_alloc(tfm, GFP_KERNEL);
		if (!req)
		goto error_free_tfm;

		sg_init_one(&in_sg, in, params->in_len);
		sg_init_one(&out_sg, out, params->out_len);
		akcipher_request_set_crypt(req, &in_sg, &out_sg, params->in_len,
		params->out_len);
		crypto_init_wait(&cwait);
		akcipher_request_set_callback(req, CRYPTO_TFM_REQ_MAY_BACKLOG \|
		CRYPTO_TFM_REQ_MAY_SLEEP,
		crypto_req_done, &cwait);

		ret = crypto_akcipher_encrypt(req);
		ret = crypto_wait_req(ret, &cwait);

		if (ret == 0)
		ret = req->dst_len;

		akcipher_request_free(req);
		error_free_tfm:
		crypto_free_akcipher(tfm);
		pr_devel("<==%s() = %d\n", __func__, ret);
		return ret;
		}

		/*
		* Do encryption, decryption and signing ops.
		*/
		static int tpm_key_eds_op(struct kernel_pkey_params *params,
		const void in, void out)
		{
		struct tpm_key *tk = params->key->payload.data[asym_crypto];
		int ret = -EOPNOTSUPP;

		/* Perform the encryption calculation. */
		switch (params->op) {
		case kernel_pkey_encrypt:
		ret = tpm_key_encrypt(tk, params, in, out);
		break;
		default:
		BUG();
		}

		return ret;
		}

		/*
		* Parse enough information out of TPM_KEY structure:
		* TPM_STRUCT_VER -> 4 bytes
		@@ -329,6 +412,7 @@ struct asymmetric_key_subtype asym_tpm_subtype = {
		.describe = asym_tpm_describe,
		.destroy = asym_tpm_destroy,
		.query = tpm_key_query,
		.eds_op = tpm_key_eds_op,
		};
		EXPORT_SYMBOL_GPL(asym_tpm_subtype);

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