1 // SPDX-License-Identifier: BSD-2-Clause
2 /*
3 * Copyright (c) 2019, Linaro Limited
4 */
5
6 #include <crypto/crypto.h>
7 #include <kernel/tee_common_otp.h>
8 #include <string_ext.h>
9 #include <tee/tee_ta_enc_manager.h>
10 #include <trace.h>
11
tee_ta_decrypt_init(void ** enc_ctx,struct shdr_encrypted_ta * ehdr,size_t len)12 TEE_Result tee_ta_decrypt_init(void **enc_ctx, struct shdr_encrypted_ta *ehdr,
13 size_t len)
14 {
15 TEE_Result res = TEE_SUCCESS;
16 uint8_t key[TEE_TA_ENC_KEY_SIZE] = {0};
17
18 res = crypto_authenc_alloc_ctx(enc_ctx, ehdr->enc_algo);
19 if (res != TEE_SUCCESS)
20 return res;
21
22 res = tee_otp_get_ta_enc_key(ehdr->flags & SHDR_ENC_KEY_TYPE_MASK,
23 key, sizeof(key));
24 if (res != TEE_SUCCESS)
25 goto out_init;
26
27 res = crypto_authenc_init(*enc_ctx, TEE_MODE_DECRYPT, key, sizeof(key),
28 SHDR_ENC_GET_IV(ehdr), ehdr->iv_size,
29 ehdr->tag_size, 0, len);
30
31 out_init:
32 if (res != TEE_SUCCESS)
33 crypto_authenc_free_ctx(*enc_ctx);
34
35 memzero_explicit(key, sizeof(key));
36 return res;
37 }
38
tee_ta_decrypt_update(void * enc_ctx,uint8_t * dst,uint8_t * src,size_t len)39 TEE_Result tee_ta_decrypt_update(void *enc_ctx, uint8_t *dst, uint8_t *src,
40 size_t len)
41 {
42 TEE_Result res = TEE_SUCCESS;
43 size_t dlen = len;
44
45 res = crypto_authenc_update_payload(enc_ctx, TEE_MODE_DECRYPT, src, len,
46 dst, &dlen);
47 if (res != TEE_SUCCESS)
48 crypto_authenc_free_ctx(enc_ctx);
49
50 return res;
51 }
52
tee_ta_decrypt_final(void * enc_ctx,struct shdr_encrypted_ta * ehdr,uint8_t * dst,uint8_t * src,size_t len)53 TEE_Result tee_ta_decrypt_final(void *enc_ctx, struct shdr_encrypted_ta *ehdr,
54 uint8_t *dst, uint8_t *src, size_t len)
55 {
56 TEE_Result res = TEE_SUCCESS;
57 size_t dlen = len;
58
59 res = crypto_authenc_dec_final(enc_ctx, src, len, dst, &dlen,
60 SHDR_ENC_GET_TAG(ehdr), ehdr->tag_size);
61
62 crypto_authenc_free_ctx(enc_ctx);
63
64 return res;
65 }
66