1 /**
2  * \file ssl_invasive.h
3  *
4  * \brief SSL module: interfaces for invasive testing only.
5  *
6  * The interfaces in this file are intended for testing purposes only.
7  * They SHOULD NOT be made available in library integrations except when
8  * building the library for testing.
9  */
10 /*
11  *  Copyright The Mbed TLS Contributors
12  *  SPDX-License-Identifier: Apache-2.0
13  *
14  *  Licensed under the Apache License, Version 2.0 (the "License"); you may
15  *  not use this file except in compliance with the License.
16  *  You may obtain a copy of the License at
17  *
18  *  http://www.apache.org/licenses/LICENSE-2.0
19  *
20  *  Unless required by applicable law or agreed to in writing, software
21  *  distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
22  *  WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
23  *  See the License for the specific language governing permissions and
24  *  limitations under the License.
25  */
26 #ifndef MBEDTLS_SSL_INVASIVE_H
27 #define MBEDTLS_SSL_INVASIVE_H
28 
29 #include "common.h"
30 #include "mbedtls/md.h"
31 
32 #if defined(MBEDTLS_TEST_HOOKS) &&              \
33     defined(MBEDTLS_SSL_SOME_SUITES_USE_TLS_CBC)
34 /** \brief Compute the HMAC of variable-length data with constant flow.
35  *
36  * This function computes the HMAC of the concatenation of \p add_data and \p
37  * data, and does with a code flow and memory access pattern that does not
38  * depend on \p data_len_secret, but only on \p min_data_len and \p
39  * max_data_len. In particular, this function always reads exactly \p
40  * max_data_len bytes from \p data.
41  *
42  * \param ctx               The HMAC context. It must have keys configured
43  *                          with mbedtls_md_hmac_starts() and use one of the
44  *                          following hashes: SHA-384, SHA-256, SHA-1 or MD-5.
45  *                          It is reset using mbedtls_md_hmac_reset() after
46  *                          the computation is complete to prepare for the
47  *                          next computation.
48  * \param add_data          The additional data prepended to \p data. This
49  *                          must point to a readable buffer of \p add_data_len
50  *                          bytes.
51  * \param add_data_len      The length of \p add_data in bytes.
52  * \param data              The data appended to \p add_data. This must point
53  *                          to a readable buffer of \p max_data_len bytes.
54  * \param data_len_secret   The length of the data to process in \p data.
55  *                          This must be no less than \p min_data_len and no
56  *                          greater than \p max_data_len.
57  * \param min_data_len      The minimal length of \p data in bytes.
58  * \param max_data_len      The maximal length of \p data in bytes.
59  * \param output            The HMAC will be written here. This must point to
60  *                          a writable buffer of sufficient size to hold the
61  *                          HMAC value.
62  *
63  * \retval 0
64  *         Success.
65  * \retval MBEDTLS_ERR_PLATFORM_HW_ACCEL_FAILED
66  *         The hardware accelerator failed.
67  */
68 int mbedtls_ssl_cf_hmac(
69         mbedtls_md_context_t *ctx,
70         const unsigned char *add_data, size_t add_data_len,
71         const unsigned char *data, size_t data_len_secret,
72         size_t min_data_len, size_t max_data_len,
73         unsigned char *output );
74 
75 /** \brief Copy data from a secret position with constant flow.
76  *
77  * This function copies \p len bytes from \p src_base + \p offset_secret to \p
78  * dst, with a code flow and memory access pattern that does not depend on \p
79  * offset_secret, but only on \p offset_min, \p offset_max and \p len.
80  *
81  * \param dst           The destination buffer. This must point to a writable
82  *                      buffer of at least \p len bytes.
83  * \param src_base      The base of the source buffer. This must point to a
84  *                      readable buffer of at least \p offset_max + \p len
85  *                      bytes.
86  * \param offset_secret The offset in the source buffer from which to copy.
87  *                      This must be no less than \p offset_min and no greater
88  *                      than \p offset_max.
89  * \param offset_min    The minimal value of \p offset_secret.
90  * \param offset_max    The maximal value of \p offset_secret.
91  * \param len           The number of bytes to copy.
92  */
93 void mbedtls_ssl_cf_memcpy_offset( unsigned char *dst,
94                                    const unsigned char *src_base,
95                                    size_t offset_secret,
96                                    size_t offset_min, size_t offset_max,
97                                    size_t len );
98 #endif /* MBEDTLS_TEST_HOOKS && MBEDTLS_SSL_SOME_SUITES_USE_TLS_CBC */
99 
100 #endif /* MBEDTLS_SSL_INVASIVE_H */
101