1 // SPDX-License-Identifier: BSD-2-Clause 2 /* 3 * Copyright (C) 2019, Linaro Limited 4 * Copyright (C) 2021, Huawei Technologies Co., Ltd 5 */ 6 7 #include <assert.h> 8 #include <compiler.h> 9 #include <crypto/crypto_accel.h> 10 #include <crypto/crypto.h> 11 #include <crypto/crypto_impl.h> 12 #include <mbedtls/aes.h> 13 #include <stdlib.h> 14 #include <string.h> 15 #include <tee_api_types.h> 16 #include <utee_defines.h> 17 #include <util.h> 18 19 #include "mbed_helpers.h" 20 21 struct mbed_aes_ctr_ctx { 22 struct crypto_cipher_ctx ctx; 23 mbedtls_aes_context aes_ctx; 24 size_t nc_off; 25 unsigned char counter[TEE_AES_BLOCK_SIZE]; 26 unsigned char block[TEE_AES_BLOCK_SIZE]; 27 }; 28 29 static const struct crypto_cipher_ops mbed_aes_ctr_ops; 30 31 static struct mbed_aes_ctr_ctx *to_aes_ctr_ctx(struct crypto_cipher_ctx *ctx) 32 { 33 assert(ctx && ctx->ops == &mbed_aes_ctr_ops); 34 35 return container_of(ctx, struct mbed_aes_ctr_ctx, ctx); 36 } 37 38 static TEE_Result mbed_aes_ctr_init(struct crypto_cipher_ctx *ctx, 39 TEE_OperationMode mode __unused, 40 const uint8_t *key1, size_t key1_len, 41 const uint8_t *key2 __unused, 42 size_t key2_len __unused, 43 const uint8_t *iv, size_t iv_len) 44 { 45 struct mbed_aes_ctr_ctx *c = to_aes_ctr_ctx(ctx); 46 47 if (iv_len != sizeof(c->counter)) 48 return TEE_ERROR_BAD_PARAMETERS; 49 memcpy(c->counter, iv, sizeof(c->counter)); 50 51 mbedtls_aes_init(&c->aes_ctx); 52 c->nc_off = 0; 53 54 if (mbedtls_aes_setkey_enc(&c->aes_ctx, key1, key1_len * 8)) 55 return TEE_ERROR_BAD_STATE; 56 57 return TEE_SUCCESS; 58 } 59 60 static TEE_Result mbed_aes_ctr_update(struct crypto_cipher_ctx *ctx, 61 bool last_block __unused, 62 const uint8_t *data, size_t len, 63 uint8_t *dst) 64 { 65 struct mbed_aes_ctr_ctx *c = to_aes_ctr_ctx(ctx); 66 67 if (mbedtls_aes_crypt_ctr(&c->aes_ctx, len, &c->nc_off, c->counter, 68 c->block, data, dst)) 69 return TEE_ERROR_BAD_STATE; 70 71 return TEE_SUCCESS; 72 } 73 74 static void mbed_aes_ctr_final(struct crypto_cipher_ctx *ctx) 75 { 76 struct mbed_aes_ctr_ctx *c = to_aes_ctr_ctx(ctx); 77 78 mbedtls_aes_free(&c->aes_ctx); 79 memset(c->block, 0, sizeof(c->block)); 80 } 81 82 static void mbed_aes_ctr_free_ctx(struct crypto_cipher_ctx *ctx) 83 { 84 free(to_aes_ctr_ctx(ctx)); 85 } 86 87 static void mbed_aes_ctr_copy_state(struct crypto_cipher_ctx *dst_ctx, 88 struct crypto_cipher_ctx *src_ctx) 89 { 90 struct mbed_aes_ctr_ctx *src = to_aes_ctr_ctx(src_ctx); 91 struct mbed_aes_ctr_ctx *dst = to_aes_ctr_ctx(dst_ctx); 92 93 memcpy(dst->counter, src->counter, sizeof(dst->counter)); 94 memcpy(dst->block, src->block, sizeof(dst->block)); 95 dst->nc_off = src->nc_off; 96 mbed_copy_mbedtls_aes_context(&dst->aes_ctx, &src->aes_ctx); 97 } 98 99 static const struct crypto_cipher_ops mbed_aes_ctr_ops = { 100 .init = mbed_aes_ctr_init, 101 .update = mbed_aes_ctr_update, 102 .final = mbed_aes_ctr_final, 103 .free_ctx = mbed_aes_ctr_free_ctx, 104 .copy_state = mbed_aes_ctr_copy_state, 105 }; 106 107 TEE_Result crypto_aes_ctr_alloc_ctx(struct crypto_cipher_ctx **ctx_ret) 108 { 109 struct mbed_aes_ctr_ctx *c = NULL; 110 111 c = calloc(1, sizeof(*c)); 112 if (!c) 113 return TEE_ERROR_OUT_OF_MEMORY; 114 115 c->ctx.ops = &mbed_aes_ctr_ops; 116 *ctx_ret = &c->ctx; 117 118 return TEE_SUCCESS; 119 } 120 121 #if defined(MBEDTLS_AES_ALT) 122 static void next_ctr(unsigned char stream_block[16], mbedtls_aes_context *ctx, 123 unsigned char nonce_counter[16]) 124 { 125 const unsigned char zeroes[16] = { 0 }; 126 127 crypto_accel_aes_ctr_be_enc(stream_block, zeroes, ctx->key, 128 ctx->round_count, 1, nonce_counter); 129 } 130 131 int mbedtls_aes_crypt_ctr(mbedtls_aes_context *ctx, size_t length, 132 size_t *nc_off, unsigned char nonce_counter[16], 133 unsigned char stream_block[16], 134 const unsigned char *input, unsigned char *output) 135 { 136 size_t offs = 0; 137 138 if (*nc_off >= 16) 139 return MBEDTLS_ERR_AES_BAD_INPUT_DATA; 140 141 /* 142 * If the stream_block is in use, continue until done or 143 * stream_block is consumed. 144 */ 145 while (*nc_off) { 146 output[offs] = stream_block[*nc_off] ^ input[offs]; 147 offs++; 148 *nc_off = (*nc_off + 1) % 16; 149 if (offs == length) 150 return 0; 151 } 152 153 if ((length - offs) >= 16) { 154 size_t block_count = (length - offs) / 16; 155 156 crypto_accel_aes_ctr_be_enc(output + offs, input + offs, 157 ctx->key, ctx->round_count, 158 block_count, nonce_counter); 159 offs += block_count * 16; 160 } 161 162 while (offs < length) { 163 if (!*nc_off) 164 next_ctr(stream_block, ctx, nonce_counter); 165 output[offs] = stream_block[*nc_off] ^ input[offs]; 166 offs++; 167 *nc_off = (*nc_off + 1) % 16; 168 } 169 170 return 0; 171 } 172 #endif /*MBEDTLS_AES_ALT*/ 173