u-boot/drivers/mmc/rpmb.c
Tom Rini 83d290c56f SPDX: Convert all of our single license tags to Linux Kernel style
When U-Boot started using SPDX tags we were among the early adopters and
there weren't a lot of other examples to borrow from.  So we picked the
area of the file that usually had a full license text and replaced it
with an appropriate SPDX-License-Identifier: entry.  Since then, the
Linux Kernel has adopted SPDX tags and they place it as the very first
line in a file (except where shebangs are used, then it's second line)
and with slightly different comment styles than us.

In part due to community overlap, in part due to better tag visibility
and in part for other minor reasons, switch over to that style.

This commit changes all instances where we have a single declared
license in the tag as both the before and after are identical in tag
contents.  There's also a few places where I found we did not have a tag
and have introduced one.

Signed-off-by: Tom Rini <trini@konsulko.com>
2018-05-07 09:34:12 -04:00

323 lines
7.9 KiB
C

// SPDX-License-Identifier: GPL-2.0+
/*
* Copyright 2014, Staubli Faverges
* Pierre Aubert
*
* eMMC- Replay Protected Memory Block
* According to JEDEC Standard No. 84-A441
*/
#include <config.h>
#include <common.h>
#include <memalign.h>
#include <mmc.h>
#include <u-boot/sha256.h>
#include "mmc_private.h"
/* Request codes */
#define RPMB_REQ_KEY 1
#define RPMB_REQ_WCOUNTER 2
#define RPMB_REQ_WRITE_DATA 3
#define RPMB_REQ_READ_DATA 4
#define RPMB_REQ_STATUS 5
/* Response code */
#define RPMB_RESP_KEY 0x0100
#define RPMB_RESP_WCOUNTER 0x0200
#define RPMB_RESP_WRITE_DATA 0x0300
#define RPMB_RESP_READ_DATA 0x0400
/* Error codes */
#define RPMB_OK 0
#define RPMB_ERR_GENERAL 1
#define RPMB_ERR_AUTH 2
#define RPMB_ERR_COUNTER 3
#define RPMB_ERR_ADDRESS 4
#define RPMB_ERR_WRITE 5
#define RPMB_ERR_READ 6
#define RPMB_ERR_KEY 7
#define RPMB_ERR_CNT_EXPIRED 0x80
#define RPMB_ERR_MSK 0x7
/* Sizes of RPMB data frame */
#define RPMB_SZ_STUFF 196
#define RPMB_SZ_MAC 32
#define RPMB_SZ_DATA 256
#define RPMB_SZ_NONCE 16
#define SHA256_BLOCK_SIZE 64
/* Error messages */
static const char * const rpmb_err_msg[] = {
"",
"General failure",
"Authentication failure",
"Counter failure",
"Address failure",
"Write failure",
"Read failure",
"Authentication key not yet programmed",
};
/* Structure of RPMB data frame. */
struct s_rpmb {
unsigned char stuff[RPMB_SZ_STUFF];
unsigned char mac[RPMB_SZ_MAC];
unsigned char data[RPMB_SZ_DATA];
unsigned char nonce[RPMB_SZ_NONCE];
unsigned int write_counter;
unsigned short address;
unsigned short block_count;
unsigned short result;
unsigned short request;
};
static int mmc_set_blockcount(struct mmc *mmc, unsigned int blockcount,
bool is_rel_write)
{
struct mmc_cmd cmd = {0};
cmd.cmdidx = MMC_CMD_SET_BLOCK_COUNT;
cmd.cmdarg = blockcount & 0x0000FFFF;
if (is_rel_write)
cmd.cmdarg |= 1 << 31;
cmd.resp_type = MMC_RSP_R1;
return mmc_send_cmd(mmc, &cmd, NULL);
}
static int mmc_rpmb_request(struct mmc *mmc, const struct s_rpmb *s,
unsigned int count, bool is_rel_write)
{
struct mmc_cmd cmd = {0};
struct mmc_data data;
int ret;
ret = mmc_set_blockcount(mmc, count, is_rel_write);
if (ret) {
#ifdef CONFIG_MMC_RPMB_TRACE
printf("%s:mmc_set_blockcount-> %d\n", __func__, ret);
#endif
return 1;
}
cmd.cmdidx = MMC_CMD_WRITE_MULTIPLE_BLOCK;
cmd.cmdarg = 0;
cmd.resp_type = MMC_RSP_R1b;
data.src = (const char *)s;
data.blocks = 1;
data.blocksize = MMC_MAX_BLOCK_LEN;
data.flags = MMC_DATA_WRITE;
ret = mmc_send_cmd(mmc, &cmd, &data);
if (ret) {
#ifdef CONFIG_MMC_RPMB_TRACE
printf("%s:mmc_send_cmd-> %d\n", __func__, ret);
#endif
return 1;
}
return 0;
}
static int mmc_rpmb_response(struct mmc *mmc, struct s_rpmb *s,
unsigned short expected)
{
struct mmc_cmd cmd = {0};
struct mmc_data data;
int ret;
ret = mmc_set_blockcount(mmc, 1, false);
if (ret) {
#ifdef CONFIG_MMC_RPMB_TRACE
printf("%s:mmc_set_blockcount-> %d\n", __func__, ret);
#endif
return -1;
}
cmd.cmdidx = MMC_CMD_READ_MULTIPLE_BLOCK;
cmd.cmdarg = 0;
cmd.resp_type = MMC_RSP_R1;
data.dest = (char *)s;
data.blocks = 1;
data.blocksize = MMC_MAX_BLOCK_LEN;
data.flags = MMC_DATA_READ;
ret = mmc_send_cmd(mmc, &cmd, &data);
if (ret) {
#ifdef CONFIG_MMC_RPMB_TRACE
printf("%s:mmc_send_cmd-> %d\n", __func__, ret);
#endif
return -1;
}
/* Check the response and the status */
if (be16_to_cpu(s->request) != expected) {
#ifdef CONFIG_MMC_RPMB_TRACE
printf("%s:response= %x\n", __func__,
be16_to_cpu(s->request));
#endif
return -1;
}
ret = be16_to_cpu(s->result);
if (ret) {
printf("%s %s\n", rpmb_err_msg[ret & RPMB_ERR_MSK],
(ret & RPMB_ERR_CNT_EXPIRED) ?
"Write counter has expired" : "");
}
/* Return the status of the command */
return ret;
}
static int mmc_rpmb_status(struct mmc *mmc, unsigned short expected)
{
ALLOC_CACHE_ALIGN_BUFFER(struct s_rpmb, rpmb_frame, 1);
memset(rpmb_frame, 0, sizeof(struct s_rpmb));
rpmb_frame->request = cpu_to_be16(RPMB_REQ_STATUS);
if (mmc_rpmb_request(mmc, rpmb_frame, 1, false))
return -1;
/* Read the result */
return mmc_rpmb_response(mmc, rpmb_frame, expected);
}
static void rpmb_hmac(unsigned char *key, unsigned char *buff, int len,
unsigned char *output)
{
sha256_context ctx;
int i;
unsigned char k_ipad[SHA256_BLOCK_SIZE];
unsigned char k_opad[SHA256_BLOCK_SIZE];
sha256_starts(&ctx);
/* According to RFC 4634, the HMAC transform looks like:
SHA(K XOR opad, SHA(K XOR ipad, text))
where K is an n byte key.
ipad is the byte 0x36 repeated blocksize times
opad is the byte 0x5c repeated blocksize times
and text is the data being protected.
*/
for (i = 0; i < RPMB_SZ_MAC; i++) {
k_ipad[i] = key[i] ^ 0x36;
k_opad[i] = key[i] ^ 0x5c;
}
/* remaining pad bytes are '\0' XOR'd with ipad and opad values */
for ( ; i < SHA256_BLOCK_SIZE; i++) {
k_ipad[i] = 0x36;
k_opad[i] = 0x5c;
}
sha256_update(&ctx, k_ipad, SHA256_BLOCK_SIZE);
sha256_update(&ctx, buff, len);
sha256_finish(&ctx, output);
/* Init context for second pass */
sha256_starts(&ctx);
/* start with outer pad */
sha256_update(&ctx, k_opad, SHA256_BLOCK_SIZE);
/* then results of 1st hash */
sha256_update(&ctx, output, RPMB_SZ_MAC);
/* finish up 2nd pass */
sha256_finish(&ctx, output);
}
int mmc_rpmb_get_counter(struct mmc *mmc, unsigned long *pcounter)
{
int ret;
ALLOC_CACHE_ALIGN_BUFFER(struct s_rpmb, rpmb_frame, 1);
/* Fill the request */
memset(rpmb_frame, 0, sizeof(struct s_rpmb));
rpmb_frame->request = cpu_to_be16(RPMB_REQ_WCOUNTER);
if (mmc_rpmb_request(mmc, rpmb_frame, 1, false))
return -1;
/* Read the result */
ret = mmc_rpmb_response(mmc, rpmb_frame, RPMB_RESP_WCOUNTER);
if (ret)
return ret;
*pcounter = be32_to_cpu(rpmb_frame->write_counter);
return 0;
}
int mmc_rpmb_set_key(struct mmc *mmc, void *key)
{
ALLOC_CACHE_ALIGN_BUFFER(struct s_rpmb, rpmb_frame, 1);
/* Fill the request */
memset(rpmb_frame, 0, sizeof(struct s_rpmb));
rpmb_frame->request = cpu_to_be16(RPMB_REQ_KEY);
memcpy(rpmb_frame->mac, key, RPMB_SZ_MAC);
if (mmc_rpmb_request(mmc, rpmb_frame, 1, true))
return -1;
/* read the operation status */
return mmc_rpmb_status(mmc, RPMB_RESP_KEY);
}
int mmc_rpmb_read(struct mmc *mmc, void *addr, unsigned short blk,
unsigned short cnt, unsigned char *key)
{
ALLOC_CACHE_ALIGN_BUFFER(struct s_rpmb, rpmb_frame, 1);
int i;
for (i = 0; i < cnt; i++) {
/* Fill the request */
memset(rpmb_frame, 0, sizeof(struct s_rpmb));
rpmb_frame->address = cpu_to_be16(blk + i);
rpmb_frame->request = cpu_to_be16(RPMB_REQ_READ_DATA);
if (mmc_rpmb_request(mmc, rpmb_frame, 1, false))
break;
/* Read the result */
if (mmc_rpmb_response(mmc, rpmb_frame, RPMB_RESP_READ_DATA))
break;
/* Check the HMAC if key is provided */
if (key) {
unsigned char ret_hmac[RPMB_SZ_MAC];
rpmb_hmac(key, rpmb_frame->data, 284, ret_hmac);
if (memcmp(ret_hmac, rpmb_frame->mac, RPMB_SZ_MAC)) {
printf("MAC error on block #%d\n", i);
break;
}
}
/* Copy data */
memcpy(addr + i * RPMB_SZ_DATA, rpmb_frame->data, RPMB_SZ_DATA);
}
return i;
}
int mmc_rpmb_write(struct mmc *mmc, void *addr, unsigned short blk,
unsigned short cnt, unsigned char *key)
{
ALLOC_CACHE_ALIGN_BUFFER(struct s_rpmb, rpmb_frame, 1);
unsigned long wcount;
int i;
for (i = 0; i < cnt; i++) {
if (mmc_rpmb_get_counter(mmc, &wcount)) {
printf("Cannot read RPMB write counter\n");
break;
}
/* Fill the request */
memset(rpmb_frame, 0, sizeof(struct s_rpmb));
memcpy(rpmb_frame->data, addr + i * RPMB_SZ_DATA, RPMB_SZ_DATA);
rpmb_frame->address = cpu_to_be16(blk + i);
rpmb_frame->block_count = cpu_to_be16(1);
rpmb_frame->write_counter = cpu_to_be32(wcount);
rpmb_frame->request = cpu_to_be16(RPMB_REQ_WRITE_DATA);
/* Computes HMAC */
rpmb_hmac(key, rpmb_frame->data, 284, rpmb_frame->mac);
if (mmc_rpmb_request(mmc, rpmb_frame, 1, true))
break;
/* Get status */
if (mmc_rpmb_status(mmc, RPMB_RESP_WRITE_DATA))
break;
}
return i;
}