Pankaj Gupta | 9247b40 | 2020-12-09 14:02:39 +0530 | [diff] [blame] | 1 | /* |
| 2 | * Copyright (c) 2014-2016, Freescale Semiconductor, Inc. |
| 3 | * Copyright 2017-2021 NXP |
| 4 | * |
| 5 | * SPDX-License-Identifier: BSD-3-Clause |
| 6 | * |
| 7 | */ |
| 8 | |
| 9 | #include <assert.h> |
| 10 | #include <stddef.h> |
| 11 | #include <stdint.h> |
| 12 | #include <string.h> |
| 13 | |
| 14 | #include <arch_helpers.h> |
| 15 | #include <common/debug.h> |
| 16 | #include <csf_hdr.h> |
| 17 | #include <drivers/auth/crypto_mod.h> |
| 18 | #include <drivers/auth/img_parser_mod.h> |
| 19 | #include <lib/utils.h> |
| 20 | #include <sfp.h> |
| 21 | |
| 22 | /* Temporary variables to speed up the authentication parameters search. These |
| 23 | * variables are assigned once during the integrity check and used any time an |
| 24 | * authentication parameter is requested, so we do not have to parse the image |
| 25 | * again. |
| 26 | */ |
| 27 | |
| 28 | /* Hash of Image + CSF Header + SRK table */ |
| 29 | uint8_t img_hash[SHA256_BYTES] __aligned(CACHE_WRITEBACK_GRANULE); |
| 30 | uint32_t hash_len; |
| 31 | |
| 32 | /* Key being used for authentication |
| 33 | * Points to the key in CSF header copied in DDR |
| 34 | * ESBC client key |
| 35 | */ |
| 36 | void *img_key; |
| 37 | uint32_t key_len; |
| 38 | |
| 39 | /* ESBC client signature */ |
| 40 | void *img_sign; |
| 41 | uint32_t sign_len; |
| 42 | enum sig_alg alg; |
| 43 | |
| 44 | /* Maximum OID string length ("a.b.c.d.e.f ...") */ |
| 45 | #define MAX_OID_STR_LEN 64 |
| 46 | |
| 47 | #define LIB_NAME "NXP CSFv2" |
| 48 | |
| 49 | /* |
| 50 | * Clear all static temporary variables. |
| 51 | */ |
| 52 | static void clear_temp_vars(void) |
| 53 | { |
| 54 | #define ZERO_AND_CLEAN(x) \ |
| 55 | do { \ |
| 56 | zeromem(&x, sizeof(x)); \ |
| 57 | clean_dcache_range((uintptr_t)&x, sizeof(x)); \ |
| 58 | } while (0) |
| 59 | |
| 60 | ZERO_AND_CLEAN(img_key); |
| 61 | ZERO_AND_CLEAN(img_sign); |
| 62 | ZERO_AND_CLEAN(img_hash); |
| 63 | ZERO_AND_CLEAN(key_len); |
| 64 | ZERO_AND_CLEAN(hash_len); |
| 65 | ZERO_AND_CLEAN(sign_len); |
| 66 | |
| 67 | #undef ZERO_AND_CLEAN |
| 68 | } |
| 69 | |
| 70 | /* Exported functions */ |
| 71 | |
| 72 | static void init(void) |
| 73 | { |
| 74 | clear_temp_vars(); |
| 75 | } |
| 76 | |
| 77 | /* |
| 78 | * This function would check the integrity of the CSF header |
| 79 | */ |
| 80 | static int check_integrity(void *img, unsigned int img_len) |
| 81 | { |
| 82 | int ret; |
| 83 | |
| 84 | /* |
| 85 | * The image file has been successfully loaded till here. |
| 86 | * |
| 87 | * Flush the image to main memory so that it can be authenticated |
| 88 | * by CAAM, a HW accelerator regardless of cache and MMU state. |
| 89 | */ |
| 90 | flush_dcache_range((uintptr_t) img, img_len); |
| 91 | |
| 92 | /* |
| 93 | * Image is appended at an offset of 16K (IMG_OFFSET) to the header. |
| 94 | * So the size in header should be equal to img_len - IMG_OFFSET |
| 95 | */ |
| 96 | VERBOSE("Barker code is %x\n", *(unsigned int *)img); |
| 97 | ret = validate_esbc_header(img, &img_key, &key_len, &img_sign, |
| 98 | &sign_len, &alg); |
| 99 | if (ret < 0) { |
| 100 | ERROR("Header authentication failed\n"); |
| 101 | clear_temp_vars(); |
| 102 | return IMG_PARSER_ERR; |
| 103 | } |
| 104 | /* Calculate the hash of various components from the image */ |
| 105 | ret = calc_img_hash(img, (uint8_t *)img + CSF_HDR_SZ, |
| 106 | img_len - CSF_HDR_SZ, img_hash, &hash_len); |
| 107 | if (ret != 0) { |
| 108 | ERROR("Issue in hash calculation %d\n", ret); |
| 109 | clear_temp_vars(); |
| 110 | return IMG_PARSER_ERR; |
| 111 | } |
| 112 | |
| 113 | return IMG_PARSER_OK; |
| 114 | } |
| 115 | |
| 116 | /* |
| 117 | * Extract an authentication parameter from CSF header |
| 118 | * |
| 119 | * CSF header has already been parsed and the required information like |
| 120 | * hash of data, signature, length stored in global variables has been |
| 121 | * extracted in chek_integrity function. This data |
| 122 | * is returned back to the caller. |
| 123 | */ |
| 124 | static int get_auth_param(const auth_param_type_desc_t *type_desc, |
| 125 | void *img, unsigned int img_len, |
| 126 | void **param, unsigned int *param_len) |
| 127 | { |
| 128 | int rc = IMG_PARSER_OK; |
| 129 | |
| 130 | /* We do not use img because the check_integrity function has already |
| 131 | * extracted the relevant data ( pk, sig_alg, etc) |
| 132 | */ |
| 133 | |
| 134 | switch (type_desc->type) { |
| 135 | |
| 136 | /* Hash will be returned for comparison with signature */ |
| 137 | case AUTH_PARAM_HASH: |
| 138 | *param = (void *)img_hash; |
| 139 | *param_len = (unsigned int)SHA256_BYTES; |
| 140 | break; |
| 141 | |
| 142 | /* Return the public key used for signature extracted from the SRK table |
| 143 | * after checks with key revocation |
| 144 | */ |
| 145 | case AUTH_PARAM_PUB_KEY: |
| 146 | /* Get the subject public key */ |
| 147 | /* For a 1K key - the length would be 2k/8 = 0x100 bytes |
| 148 | * 2K RSA key - 0x200 , 4K RSA - 0x400 |
| 149 | */ |
| 150 | *param = img_key; |
| 151 | *param_len = (unsigned int)key_len; |
| 152 | break; |
| 153 | |
| 154 | /* Call a function to tell if signature is RSA or ECDSA. ECDSA to be |
| 155 | * supported in later platforms like LX2 etc |
| 156 | */ |
| 157 | case AUTH_PARAM_SIG_ALG: |
| 158 | /* Algo will be signature - RSA or ECDSA on hash */ |
| 159 | *param = (void *)&alg; |
| 160 | *param_len = 4U; |
| 161 | break; |
| 162 | |
| 163 | /* Return the signature */ |
| 164 | case AUTH_PARAM_SIG: |
| 165 | *param = img_sign; |
| 166 | *param_len = (unsigned int)sign_len; |
| 167 | break; |
| 168 | |
| 169 | case AUTH_PARAM_NV_CTR: |
| 170 | |
| 171 | default: |
| 172 | rc = IMG_PARSER_ERR_NOT_FOUND; |
| 173 | break; |
| 174 | } |
| 175 | |
| 176 | return rc; |
| 177 | } |
| 178 | |
| 179 | REGISTER_IMG_PARSER_LIB(IMG_PLAT, LIB_NAME, init, |
| 180 | check_integrity, get_auth_param); |