| /* |
| * 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 <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; |
| } |