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Commit fd16bf96 authored by Gaurav Kashyap's avatar Gaurav Kashyap
Browse files

soc: qcom: hwkm: Re-format cmd packet for system kdf 



1. Fix to format context correctly as expected by
   hardware for system KDF.
   HWKM reverses bytes at a 8-byte boundary while getting
   the context from cryptolib. Reformat the context in the
   command packet in such a way that HWKM receives it in the
   correct order. Also, pad the context to a 8-byte multiple
   as the way HW would pad it is not expected.
2. Use context for FBE to match with the one
   for VTS test cases.

Change-Id: I3c13c91b0dfc85aef406b05694dbd22afb0b2e0b
Signed-off-by: default avatarGaurav Kashyap <gaurkash@codeaurora.org>
parent 1f2a0ad6

drivers/soc/qcom/crypto-qti-hwkm.c

+9 −14
Original line number Diff line number Diff line
@@ -9,6 +9,7 @@ 
#include <linux/crypto-qti-common.h>

#include <linux/hwkm.h>

#include <linux/module.h>

#include <linux/kernel.h>



#include "crypto-qti-ice-regs.h"

#include "crypto-qti-platform.h"
@@ -19,6 +20,8 @@ 


#define QTI_HWKM_INIT_DONE		0x1

#define SLOT_EMPTY_ERROR		0x1000

#define INLINECRYPT_CTX			"inline encryption key"

#define BYTE_ORDER_VAL			8



union crypto_cfg {

	__le32 regval[2];
@@ -65,19 +68,10 @@ int crypto_qti_program_key(struct crypto_vops_qti_entry *ice_entry, 
		.km_by_nsec_allowed = true,

	};

	struct hwkm_bsve bsve_kdf = {

		.enabled = false,

		.enabled = true,

		.km_swc_en = true,

		.km_child_key_policy_en = true,

	};

	u8 ctx[] = {

		0xee, 0xb6, 0xa4, 0xc8, 0x6f, 0x22, 0x5f, 0xda,

		0x18, 0xff, 0x61, 0x07, 0xfb, 0x88, 0x17, 0x7f,

		0xe4, 0x89, 0x8f, 0xed, 0xdb, 0x0c, 0x68, 0xb2,

		0x18, 0xe7, 0x58, 0xd0, 0xf7, 0x79, 0x61, 0xad,

		0x77, 0xc6, 0x4d, 0x2b, 0x53, 0x93, 0x4f, 0x34,

		0xaf, 0x51, 0xab, 0xda, 0x24, 0xa0, 0xa4, 0x76,

		0xf4, 0x09, 0xed, 0xa3, 0x2c, 0xa1, 0x8b, 0xcd,

		0x01, 0xe7, 0x0a, 0x3e, 0x9d, 0x73, 0xac, 0x96,

	};



	union crypto_cfg cfg;



	if ((key->size) <= RAW_SECRET_SIZE) {
@@ -143,8 +137,9 @@ int crypto_qti_program_key(struct crypto_vops_qti_entry *ice_entry, 
	cmd_kdf.kdf.kdk = GP_KEYSLOT;

	cmd_kdf.kdf.policy = policy_kdf;

	cmd_kdf.kdf.bsve = bsve_kdf;

	cmd_kdf.kdf.sz = 64;

	memcpy(cmd_kdf.kdf.ctx, ctx, HWKM_MAX_CTX_SIZE);

	cmd_kdf.kdf.sz = round_up(strlen(INLINECRYPT_CTX), BYTE_ORDER_VAL);

	memset(cmd_kdf.kdf.ctx, 0, HWKM_MAX_CTX_SIZE);

	memcpy(cmd_kdf.kdf.ctx, INLINECRYPT_CTX, strlen(INLINECRYPT_CTX));



	memset(&cfg, 0, sizeof(cfg));

	cfg.dusize = data_unit_mask;

drivers/soc/qcom/hwkm.c

+49 −9
Original line number Diff line number Diff line
@@ -49,6 +49,7 @@ for (retries = 0; !(cond) && (retries < MAX_RETRIES); retries++) 
#define ICEMEM_SLAVE_TPKEY_VAL	0x192

#define ICEMEM_SLAVE_TPKEY_SLOT	0x92

#define KM_MASTER_TPKEY_SLOT	10

#define BYTE_ORDER_VAL		8



struct hwkm_clk_info {

	struct list_head list;
@@ -436,15 +437,38 @@ static void deserialize_policy(struct hwkm_key_policy *out, 
	out->km_by_spu_allowed = policy->key_management_by_spu_allowed;

}



static void reverse_key(u8 *key, size_t keylen)



static void reverse_bytes(u8 *bytes, size_t len)

{

	size_t left = 0;

	size_t right = 0;



	for (left = 0, right = keylen - 1; left < right; left++, right--) {

		key[left] ^= key[right];

		key[right] ^= key[left];

		key[left] ^= key[right];

	for (left = 0, right = len - 1; left < right; left++, right--) {

		bytes[left] ^= bytes[right];

		bytes[right] ^= bytes[left];

		bytes[left] ^= bytes[right];

	}

}



static void reorder_ctx(u8 *ctx, size_t ctxlen)

{

	int i = 0;

	int len = 0;



	len = ctxlen / BYTE_ORDER_VAL;



	/* Reverse ctx at 8 byte boundary */

	for (i = 0; i < len; i++)

		reverse_bytes(ctx + i*BYTE_ORDER_VAL, BYTE_ORDER_VAL);



	/*

	 * If context is not a multiple of 8 bytes, reverse the last bytes

	 * only. This simulates prepending the last 8 bytes with zeroes,

	 * and then reversing the 8 bytes.

	 */

	if (ctxlen % BYTE_ORDER_VAL != 0) {

		reverse_bytes(ctx + len*BYTE_ORDER_VAL,

				ctxlen % BYTE_ORDER_VAL);

	}

}
@@ -590,6 +614,15 @@ static int qti_handle_system_kdf(const struct hwkm_cmd *cmd_in, 


	serialize_policy(&policy, &cmd_in->kdf.policy);



	/*

	 * If context is not a multiple of 8 bytes, but a multiple

	 * of 4 bytes, add a zero word at the end, to have a context multiple

	 * of 8 bytes. This is to facilitate the context reordering that will

	 * happen later

	 */

	if ((cmd_in->kdf.sz) % BYTE_ORDER_VAL == (BYTE_ORDER_VAL/2))

		operation.context_len += 1;



	WRITE_TO_KDF_PACKET(cmd_ptr, &operation, OPERATION_INFO_LENGTH);

	WRITE_TO_KDF_PACKET(cmd_ptr, &policy, KEY_POLICY_LENGTH);
@@ -599,10 +632,16 @@ static int qti_handle_system_kdf(const struct hwkm_cmd *cmd_in, 
		serialize_kdf_bsve(&bsve, &cmd_in->kdf.bsve, cmd_in->kdf.mks);

		WRITE_TO_KDF_PACKET(cmd_ptr, &bsve, MAX_BSVE_LENGTH);

	} else {

		// Skip the remaining 3 bytes of the current word

		cmd_ptr += 3 * (sizeof(u8));

		// Skip 4 bytes to align to start of context.

		cmd_ptr += 4 * (sizeof(u8));

	}



	/*

	 * Reorder context to reverse context bytes at the 8 byte

	 * boundary. This is because crypto lib reads at this

	 * boundary when populating the AD.

	 */

	reorder_ctx((u8 *) cmd_in->kdf.ctx, cmd_in->kdf.sz);

	WRITE_TO_KDF_PACKET(cmd_ptr, cmd_in->kdf.ctx, cmd_in->kdf.sz);



	status = qti_hwkm_run_transaction(ICEMEM_SLAVE, cmd,
@@ -724,7 +763,7 @@ static int qti_handle_keyslot_rdwr(const struct hwkm_cmd *cmd_in, 
				cmd_in->rdwr.sz);

		// Need to reverse the key because the HW expects it in reverse

		// byte order

		reverse_key((u8 *) (cmd + COMMAND_KEY_VALUE_IDX),

		reverse_bytes((u8 *) (cmd + COMMAND_KEY_VALUE_IDX),

				HWKM_MAX_KEY_SIZE);

	}
@@ -750,7 +789,8 @@ static int qti_handle_keyslot_rdwr(const struct hwkm_cmd *cmd_in, 
			rsp + RESPONSE_KEY_VALUE_IDX, RESPONSE_KEY_LENGTH);

		// Need to reverse the key because the HW returns it in

		// reverse byte order

		reverse_key(rsp_in->rdwr.key, HWKM_MAX_KEY_SIZE);

		reverse_bytes(rsp_in->rdwr.key, HWKM_MAX_KEY_SIZE);

		rsp_in->rdwr.sz = RESPONSE_KEY_LENGTH;

		deserialize_policy(&rsp_in->rdwr.policy, &policy);

	}