xref: /optee_os/lib/libmbedtls/core/aes_cbc.c (revision 10b907910d58334cc5b1486cb2f91a08f764566e)
1 // SPDX-License-Identifier: BSD-2-Clause
2 /*
3  * Copyright (C) 2019, Linaro Limited
4  */
5 
6 #include <assert.h>
7 #include <compiler.h>
8 #include <crypto/crypto_accel.h>
9 #include <crypto/crypto.h>
10 #include <crypto/crypto_impl.h>
11 #include <mbedtls/aes.h>
12 #include <stdlib.h>
13 #include <string.h>
14 #include <tee_api_types.h>
15 #include <utee_defines.h>
16 #include <util.h>
17 
18 struct mbed_aes_cbc_ctx {
19 	struct crypto_cipher_ctx ctx;
20 	int mbed_mode;
21 	mbedtls_aes_context aes_ctx;
22 	unsigned char iv[TEE_AES_BLOCK_SIZE];
23 };
24 
25 static const struct crypto_cipher_ops mbed_aes_cbc_ops;
26 
27 static struct mbed_aes_cbc_ctx *to_aes_cbc_ctx(struct crypto_cipher_ctx *ctx)
28 {
29 	assert(ctx && ctx->ops == &mbed_aes_cbc_ops);
30 
31 	return container_of(ctx, struct mbed_aes_cbc_ctx, ctx);
32 }
33 
34 static TEE_Result mbed_aes_cbc_init(struct crypto_cipher_ctx *ctx,
35 				    TEE_OperationMode mode, const uint8_t *key1,
36 				    size_t key1_len,
37 				    const uint8_t *key2 __unused,
38 				    size_t key2_len __unused,
39 				    const uint8_t *iv, size_t iv_len)
40 {
41 	struct mbed_aes_cbc_ctx *c = to_aes_cbc_ctx(ctx);
42 	int mbed_res = 0;
43 
44 	if (iv_len != sizeof(c->iv))
45 		return TEE_ERROR_BAD_PARAMETERS;
46 	memcpy(c->iv, iv, sizeof(c->iv));
47 
48 	mbedtls_aes_init(&c->aes_ctx);
49 
50 	if (mode == TEE_MODE_ENCRYPT) {
51 		c->mbed_mode = MBEDTLS_AES_ENCRYPT;
52 		mbed_res = mbedtls_aes_setkey_enc(&c->aes_ctx, key1,
53 						  key1_len * 8);
54 	} else {
55 		c->mbed_mode = MBEDTLS_AES_DECRYPT;
56 		mbed_res = mbedtls_aes_setkey_dec(&c->aes_ctx, key1,
57 						  key1_len * 8);
58 	}
59 
60 	if (mbed_res)
61 		return TEE_ERROR_BAD_STATE;
62 
63 	return TEE_SUCCESS;
64 }
65 
66 static TEE_Result mbed_aes_cbc_update(struct crypto_cipher_ctx *ctx,
67 				      bool last_block __unused,
68 				      const uint8_t *data, size_t len,
69 				      uint8_t *dst)
70 {
71 	struct mbed_aes_cbc_ctx *c = to_aes_cbc_ctx(ctx);
72 
73 	if (mbedtls_aes_crypt_cbc(&c->aes_ctx, c->mbed_mode, len, c->iv,
74 				  data, dst))
75 		return TEE_ERROR_BAD_STATE;
76 
77 	return TEE_SUCCESS;
78 }
79 
80 static void mbed_aes_cbc_final(struct crypto_cipher_ctx *ctx)
81 {
82 	mbedtls_aes_free(&to_aes_cbc_ctx(ctx)->aes_ctx);
83 }
84 
85 static void mbed_aes_cbc_free_ctx(struct crypto_cipher_ctx *ctx)
86 {
87 	free(to_aes_cbc_ctx(ctx));
88 }
89 
90 static void mbed_aes_cbc_copy_state(struct crypto_cipher_ctx *dst_ctx,
91 				    struct crypto_cipher_ctx *src_ctx)
92 {
93 	struct mbed_aes_cbc_ctx *src = to_aes_cbc_ctx(src_ctx);
94 	struct mbed_aes_cbc_ctx *dst = to_aes_cbc_ctx(dst_ctx);
95 
96 	memcpy(dst->iv, src->iv, sizeof(dst->iv));
97 	dst->mbed_mode = src->mbed_mode;
98 	dst->aes_ctx = src->aes_ctx;
99 }
100 
101 static const struct crypto_cipher_ops mbed_aes_cbc_ops = {
102 	.init = mbed_aes_cbc_init,
103 	.update = mbed_aes_cbc_update,
104 	.final = mbed_aes_cbc_final,
105 	.free_ctx = mbed_aes_cbc_free_ctx,
106 	.copy_state = mbed_aes_cbc_copy_state,
107 };
108 
109 TEE_Result crypto_aes_cbc_alloc_ctx(struct crypto_cipher_ctx **ctx_ret)
110 {
111 	struct mbed_aes_cbc_ctx *c = NULL;
112 
113 	c = calloc(1, sizeof(*c));
114 	if (!c)
115 		return TEE_ERROR_OUT_OF_MEMORY;
116 
117 	c->ctx.ops = &mbed_aes_cbc_ops;
118 	*ctx_ret = &c->ctx;
119 
120 	return TEE_SUCCESS;
121 }
122 
123 #if defined(MBEDTLS_AES_ALT)
124 int mbedtls_aes_crypt_cbc(mbedtls_aes_context *ctx, int mode, size_t length,
125 			  unsigned char iv[16], const unsigned char *input,
126 			  unsigned char *output)
127 {
128 	if (length % 16)
129 		return MBEDTLS_ERR_AES_INVALID_INPUT_LENGTH;
130 
131 	if (mode == MBEDTLS_AES_ENCRYPT)
132 		crypto_accel_aes_cbc_enc(output, input, ctx->key,
133 					 ctx->round_count, length / 16, iv);
134 	else
135 		crypto_accel_aes_cbc_dec(output, input, ctx->key,
136 					 ctx->round_count, length / 16, iv);
137 
138 	return 0;
139 }
140 #endif /*MBEDTLS_AES_ALT*/
141