1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
|
/**
* \file nist_kw.h
*
* \brief This file provides an API for key wrapping (KW) and key wrapping with
* padding (KWP) as defined in NIST SP 800-38F.
* https://nvlpubs.nist.gov/nistpubs/SpecialPublications/NIST.SP.800-38F.pdf
*
* Key wrapping specifies a deterministic authenticated-encryption mode
* of operation, according to <em>NIST SP 800-38F: Recommendation for
* Block Cipher Modes of Operation: Methods for Key Wrapping</em>. Its
* purpose is to protect cryptographic keys.
*
* Its equivalent is RFC 3394 for KW, and RFC 5649 for KWP.
* https://tools.ietf.org/html/rfc3394
* https://tools.ietf.org/html/rfc5649
*
*/
/*
* Copyright The Mbed TLS Contributors
* SPDX-License-Identifier: Apache-2.0
*
* Licensed under the Apache License, Version 2.0 (the "License"); you may
* not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#ifndef MBEDTLS_NIST_KW_H
#define MBEDTLS_NIST_KW_H
#include "mbedtls/private_access.h"
#include "mbedtls/build_info.h"
#include "mbedtls/cipher.h"
#ifdef __cplusplus
extern "C" {
#endif
typedef enum
{
MBEDTLS_KW_MODE_KW = 0,
MBEDTLS_KW_MODE_KWP = 1
} mbedtls_nist_kw_mode_t;
#if !defined(MBEDTLS_NIST_KW_ALT)
// Regular implementation
//
/**
* \brief The key wrapping context-type definition. The key wrapping context is passed
* to the APIs called.
*
* \note The definition of this type may change in future library versions.
* Don't make any assumptions on this context!
*/
typedef struct {
mbedtls_cipher_context_t MBEDTLS_PRIVATE(cipher_ctx); /*!< The cipher context used. */
} mbedtls_nist_kw_context;
#else /* MBEDTLS_NIST_key wrapping_ALT */
#include "nist_kw_alt.h"
#endif /* MBEDTLS_NIST_KW_ALT */
/**
* \brief This function initializes the specified key wrapping context
* to make references valid and prepare the context
* for mbedtls_nist_kw_setkey() or mbedtls_nist_kw_free().
*
* \param ctx The key wrapping context to initialize.
*
*/
void mbedtls_nist_kw_init( mbedtls_nist_kw_context *ctx );
/**
* \brief This function initializes the key wrapping context set in the
* \p ctx parameter and sets the encryption key.
*
* \param ctx The key wrapping context.
* \param cipher The 128-bit block cipher to use. Only AES is supported.
* \param key The Key Encryption Key (KEK).
* \param keybits The KEK size in bits. This must be acceptable by the cipher.
* \param is_wrap Specify whether the operation within the context is wrapping or unwrapping
*
* \return \c 0 on success.
* \return \c MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA for any invalid input.
* \return \c MBEDTLS_ERR_CIPHER_FEATURE_UNAVAILABLE for 128-bit block ciphers
* which are not supported.
* \return cipher-specific error code on failure of the underlying cipher.
*/
int mbedtls_nist_kw_setkey( mbedtls_nist_kw_context *ctx,
mbedtls_cipher_id_t cipher,
const unsigned char *key,
unsigned int keybits,
const int is_wrap );
/**
* \brief This function releases and clears the specified key wrapping context
* and underlying cipher sub-context.
*
* \param ctx The key wrapping context to clear.
*/
void mbedtls_nist_kw_free( mbedtls_nist_kw_context *ctx );
/**
* \brief This function encrypts a buffer using key wrapping.
*
* \param ctx The key wrapping context to use for encryption.
* \param mode The key wrapping mode to use (MBEDTLS_KW_MODE_KW or MBEDTLS_KW_MODE_KWP)
* \param input The buffer holding the input data.
* \param in_len The length of the input data in Bytes.
* The input uses units of 8 Bytes called semiblocks.
* <ul><li>For KW mode: a multiple of 8 bytes between 16 and 2^57-8 inclusive. </li>
* <li>For KWP mode: any length between 1 and 2^32-1 inclusive.</li></ul>
* \param[out] output The buffer holding the output data.
* <ul><li>For KW mode: Must be at least 8 bytes larger than \p in_len.</li>
* <li>For KWP mode: Must be at least 8 bytes larger rounded up to a multiple of
* 8 bytes for KWP (15 bytes at most).</li></ul>
* \param[out] out_len The number of bytes written to the output buffer. \c 0 on failure.
* \param[in] out_size The capacity of the output buffer.
*
* \return \c 0 on success.
* \return \c MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA for invalid input length.
* \return cipher-specific error code on failure of the underlying cipher.
*/
int mbedtls_nist_kw_wrap( mbedtls_nist_kw_context *ctx, mbedtls_nist_kw_mode_t mode,
const unsigned char *input, size_t in_len,
unsigned char *output, size_t* out_len, size_t out_size );
/**
* \brief This function decrypts a buffer using key wrapping.
*
* \param ctx The key wrapping context to use for decryption.
* \param mode The key wrapping mode to use (MBEDTLS_KW_MODE_KW or MBEDTLS_KW_MODE_KWP)
* \param input The buffer holding the input data.
* \param in_len The length of the input data in Bytes.
* The input uses units of 8 Bytes called semiblocks.
* The input must be a multiple of semiblocks.
* <ul><li>For KW mode: a multiple of 8 bytes between 24 and 2^57 inclusive. </li>
* <li>For KWP mode: a multiple of 8 bytes between 16 and 2^32 inclusive.</li></ul>
* \param[out] output The buffer holding the output data.
* The output buffer's minimal length is 8 bytes shorter than \p in_len.
* \param[out] out_len The number of bytes written to the output buffer. \c 0 on failure.
* For KWP mode, the length could be up to 15 bytes shorter than \p in_len,
* depending on how much padding was added to the data.
* \param[in] out_size The capacity of the output buffer.
*
* \return \c 0 on success.
* \return \c MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA for invalid input length.
* \return \c MBEDTLS_ERR_CIPHER_AUTH_FAILED for verification failure of the ciphertext.
* \return cipher-specific error code on failure of the underlying cipher.
*/
int mbedtls_nist_kw_unwrap( mbedtls_nist_kw_context *ctx, mbedtls_nist_kw_mode_t mode,
const unsigned char *input, size_t in_len,
unsigned char *output, size_t* out_len, size_t out_size);
#if defined(MBEDTLS_SELF_TEST) && defined(MBEDTLS_AES_C)
/**
* \brief The key wrapping checkup routine.
*
* \return \c 0 on success.
* \return \c 1 on failure.
*/
int mbedtls_nist_kw_self_test( int verbose );
#endif /* MBEDTLS_SELF_TEST && MBEDTLS_AES_C */
#ifdef __cplusplus
}
#endif
#endif /* MBEDTLS_NIST_KW_H */
|
