1 /* 2 * Copyright (c) 2024-2025, Arm Limited. All rights reserved. 3 * 4 * SPDX-License-Identifier: BSD-3-Clause 5 */ 6 7 #include <assert.h> 8 #include <stdint.h> 9 #include <string.h> 10 11 #include <psa/crypto_types.h> 12 #include <psa/crypto_values.h> 13 14 #include <common/debug.h> 15 #include <drivers/auth/crypto_mod.h> 16 #include <drivers/measured_boot/rse/dice_prot_env.h> 17 #include <lib/cassert.h> 18 #include <lib/psa/dice_protection_environment.h> 19 20 #include <platform_def.h> 21 22 #define DPE_ALG_SHA512 0 23 #define DPE_ALG_SHA384 1 24 #define DPE_ALG_SHA256 2 25 26 #if DPE_ALG_ID == DPE_ALG_SHA512 27 #define CRYPTO_MD_ID CRYPTO_MD_SHA512 28 #define PSA_CRYPTO_MD_ID PSA_ALG_SHA_512 29 #elif DPE_ALG_ID == DPE_ALG_SHA384 30 #define CRYPTO_MD_ID CRYPTO_MD_SHA384 31 #define PSA_CRYPTO_MD_ID PSA_ALG_SHA_384 32 #elif DPE_ALG_ID == DPE_ALG_SHA256 33 #define CRYPTO_MD_ID CRYPTO_MD_SHA256 34 #define PSA_CRYPTO_MD_ID PSA_ALG_SHA_256 35 #else 36 # error Invalid DPE hash algorithm. 37 #endif /* DPE_ALG_ID */ 38 39 /* Ensure that computed hash values fits into the DiceInputValues structure */ 40 CASSERT(DICE_HASH_SIZE >= DPE_DIGEST_SIZE, 41 assert_digest_size_bigger_than_allocated_buffer); 42 43 static int initial_context_handle; 44 45 static void map_metadata_to_dice_inputs(struct dpe_metadata *metadata, 46 DiceInputValues *dice_inputs) 47 { 48 /* Hash of the content certificate signing key (public part) */ 49 memcpy(dice_inputs->authority_hash, metadata->signer_id, 50 DPE_DIGEST_SIZE); 51 52 /* SW type string identifier */ 53 assert(metadata->sw_type_size < DICE_CODE_DESCRIPTOR_MAX_SIZE); 54 dice_inputs->code_descriptor = metadata->sw_type; 55 dice_inputs->code_descriptor_size = metadata->sw_type_size; 56 } 57 58 void dpe_init(struct dpe_metadata *metadata) 59 { 60 assert(metadata != NULL); 61 62 /* Init the non-const members of the metadata structure */ 63 while (metadata->id != DPE_INVALID_ID) { 64 /* Terminating 0 character is not needed due to CBOR encoding */ 65 metadata->sw_type_size = 66 strlen((const char *)&metadata->sw_type); 67 metadata++; 68 } 69 70 plat_dpe_get_context_handle(&initial_context_handle); 71 } 72 73 int dpe_measure_and_record(struct dpe_metadata *metadata, 74 uintptr_t data_base, uint32_t data_size, 75 uint32_t data_id) 76 { 77 static int current_context_handle; 78 DiceInputValues dice_inputs = { 0 }; 79 int new_parent_context_handle = 0; 80 int new_context_handle; 81 dpe_error_t ret; 82 int rc; 83 84 assert(metadata != NULL); 85 86 /* Get the metadata associated with this image. */ 87 while ((metadata->id != DPE_INVALID_ID) && (metadata->id != data_id)) { 88 metadata++; 89 } 90 91 /* If image is not present in metadata array then skip */ 92 if (metadata->id == DPE_INVALID_ID) { 93 return 0; 94 } 95 96 /* Calculate hash */ 97 rc = crypto_mod_calc_hash(CRYPTO_MD_ID, 98 (void *)data_base, data_size, 99 dice_inputs.code_hash); 100 if (rc != 0) { 101 return rc; 102 } 103 104 map_metadata_to_dice_inputs(metadata, &dice_inputs); 105 106 /* Only at the first call */ 107 if (current_context_handle == 0) { 108 current_context_handle = initial_context_handle; 109 } 110 111 VERBOSE("Calling dpe_derive_context, image_id: %d\n", metadata->id); 112 ret = dpe_derive_context(current_context_handle, 113 metadata->cert_id, 114 metadata->retain_parent_context, 115 metadata->allow_new_context_to_derive, 116 metadata->create_certificate, 117 &dice_inputs, 118 metadata->target_locality, 119 false, /* return_certificate */ 120 true, /* allow_new_context_to_export */ 121 false, /* export_cdi */ 122 &new_context_handle, 123 &new_parent_context_handle, 124 NULL, 0, NULL, /* new_certificate_* */ 125 NULL, 0, NULL); /* exported_cdi_* */ 126 if (ret == DPE_NO_ERROR) { 127 current_context_handle = new_parent_context_handle; 128 if (metadata->allow_new_context_to_derive == true) { 129 /* Share new_context_handle with child component: 130 * e.g: BL2, BL33. 131 */ 132 VERBOSE("Share new_context_handle with child: 0x%x\n", 133 new_context_handle); 134 plat_dpe_share_context_handle(&new_context_handle, 135 &new_parent_context_handle); 136 } 137 } else { 138 ERROR("dpe_derive_context failed: %d\n", ret); 139 } 140 141 return (ret == DPE_NO_ERROR) ? 0 : -1; 142 } 143 144 int dpe_set_signer_id(struct dpe_metadata *metadata, 145 const void *pk_oid, 146 const void *pk_ptr, 147 size_t pk_len) 148 { 149 unsigned char hash_data[CRYPTO_MD_MAX_SIZE]; 150 int rc; 151 bool hash_calc_done = false; 152 153 assert(metadata != NULL); 154 155 /* 156 * Do an exhaustive search over the platform metadata to find 157 * all images whose key OID matches the one passed in argument. 158 * 159 * Note that it is not an error if do not get any matches. 160 * The platform may decide not to measure all of the images 161 * in the system. 162 */ 163 while (metadata->id != DPE_INVALID_ID) { 164 /* Get the metadata associated with this key-oid */ 165 if (metadata->pk_oid == pk_oid) { 166 if (hash_calc_done == false) { 167 /* Calculate public key hash */ 168 rc = crypto_mod_calc_hash(CRYPTO_MD_ID, 169 (void *)pk_ptr, 170 pk_len, hash_data); 171 if (rc != 0) { 172 return rc; 173 } 174 175 hash_calc_done = true; 176 } 177 178 /* 179 * Fill the signer-ID field with the newly/already 180 * computed hash of the public key and update its 181 * signer ID size field with compile-time decided 182 * digest size. 183 */ 184 (void)memcpy(metadata->signer_id, 185 hash_data, 186 DPE_DIGEST_SIZE); 187 metadata->signer_id_size = DPE_DIGEST_SIZE; 188 } 189 190 metadata++; 191 } 192 193 return 0; 194 } 195