--- /dev/null
+/*
+ * Copyright 2014, Staubli Faverges
+ * Pierre Aubert
+ *
+ * eMMC- Replay Protected Memory Block
+ * According to JEDEC Standard No. 84-A441
+ *
+ * SPDX-License-Identifier: GPL-2.0+
+ */
+
+#include <config.h>
+#include <common.h>
+#include <mmc.h>
+#include <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 long 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;
+}
projects / oweals / u-boot.git / commitdiff