65 lines
2.3 KiB
C
65 lines
2.3 KiB
C
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/**
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* \file psa_crypto_core_common.h
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*
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* \brief Utility macros for internal use in the PSA cryptography core.
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*/
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/*
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* Copyright The Mbed TLS Contributors
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* SPDX-License-Identifier: Apache-2.0
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*
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* Licensed under the Apache License, Version 2.0 (the "License"); you may
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* not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
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* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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#ifndef PSA_CRYPTO_CORE_COMMON_H
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#define PSA_CRYPTO_CORE_COMMON_H
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/** Return an offset into a buffer.
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*
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* This is just the addition of an offset to a pointer, except that this
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* function also accepts an offset of 0 into a buffer whose pointer is null.
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* (`p + n` has undefined behavior when `p` is null, even when `n == 0`.
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* A null pointer is a valid buffer pointer when the size is 0, for example
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* as the result of `malloc(0)` on some platforms.)
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*
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* \param p Pointer to a buffer of at least n bytes.
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* This may be \p NULL if \p n is zero.
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* \param n An offset in bytes.
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* \return Pointer to offset \p n in the buffer \p p.
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* Note that this is only a valid pointer if the size of the
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* buffer is at least \p n + 1.
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*/
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static inline unsigned char *psa_crypto_buffer_offset(
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unsigned char *p, size_t n)
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{
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return p == NULL ? NULL : p + n;
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}
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/** Return an offset into a read-only buffer.
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*
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* Similar to mbedtls_buffer_offset(), but for const pointers.
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*
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* \param p Pointer to a buffer of at least n bytes.
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* This may be \p NULL if \p n is zero.
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* \param n An offset in bytes.
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* \return Pointer to offset \p n in the buffer \p p.
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* Note that this is only a valid pointer if the size of the
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* buffer is at least \p n + 1.
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*/
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static inline const unsigned char *psa_crypto_buffer_offset_const(
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const unsigned char *p, size_t n)
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{
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return p == NULL ? NULL : p + n;
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}
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#endif /* PSA_CRYPTO_CORE_COMMON_H */
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