// Copyright 2018 The BoringSSL Authors

//

// 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

//

//     https://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 OPENSSL_HEADER_CRYPTO_CHACHA_INTERNAL_H

#define OPENSSL_HEADER_CRYPTO_CHACHA_INTERNAL_H

#include <openssl/base.h>

#include "../internal.h"

BSSL_NAMESPACE_BEGIN

// CRYPTO_hchacha20 computes the HChaCha20 function, which should only be used

// as part of XChaCha20.

void CRYPTO_hchacha20(uint8_t out[32], const uint8_t key[32],

                      const uint8_t nonce[16]);

#if !defined(OPENSSL_NO_ASM) && defined(OPENSSL_X86)

#define CHACHA20_ASM_NOHW

#define CHACHA20_ASM_SSSE3

inline int ChaCha20_ctr32_ssse3_capable(size_t len) {

  // Unlike the x86_64 version, the x86 SSSE3 routine runs for all non-zero

  // lengths.

  return len > 0 && CRYPTO_is_SSSE3_capable();

}

extern "C" void ChaCha20_ctr32_ssse3(uint8_t *out, const uint8_t *in,

                                     size_t in_len, const uint32_t key[8],

                                     const uint32_t counter[4]);

#elif !defined(OPENSSL_NO_ASM) && \

    (defined(OPENSSL_ARM) || defined(OPENSSL_AARCH64))

#define CHACHA20_ASM_NOHW

#define CHACHA20_ASM_NEON

inline int ChaCha20_ctr32_neon_capable(size_t len) {

  return len >= 192 && CRYPTO_is_NEON_capable();

}

extern "C" void ChaCha20_ctr32_neon(uint8_t *out, const uint8_t *in,

                                    size_t in_len, const uint32_t key[8],

                                    const uint32_t counter[4]);

#elif !defined(OPENSSL_NO_ASM) && defined(OPENSSL_X86_64)

#define CHACHA20_ASM_NOHW

#define CHACHA20_ASM_AVX2

inline int ChaCha20_ctr32_avx2_capable(size_t len) {

  return len > 128 && CRYPTO_is_AVX2_capable();

}

extern "C" void ChaCha20_ctr32_avx2(uint8_t *out, const uint8_t *in,

                                    size_t in_len, const uint32_t key[8],

                                    const uint32_t counter[4]);

#define CHACHA20_ASM_SSSE3_4X

inline int ChaCha20_ctr32_ssse3_4x_capable(size_t len) {

  int capable = len > 128 && CRYPTO_is_SSSE3_capable();

  int faster = len > 192 || !CRYPTO_cpu_perf_is_like_silvermont();

  return capable && faster;

}

extern "C" void ChaCha20_ctr32_ssse3_4x(uint8_t *out, const uint8_t *in,

                                        size_t in_len, const uint32_t key[8],

                                        const uint32_t counter[4]);

#define CHACHA20_ASM_SSSE3

inline int ChaCha20_ctr32_ssse3_capable(size_t len) {

  return len > 128 && CRYPTO_is_SSSE3_capable();

}

extern "C" void ChaCha20_ctr32_ssse3(uint8_t *out, const uint8_t *in,

                                     size_t in_len, const uint32_t key[8],

                                     const uint32_t counter[4]);

#endif

#if defined(CHACHA20_ASM_NOHW)

// ChaCha20_ctr32_nohw encrypts `in_len` bytes from `in` and writes the result

// to `out`. If `in` and `out` alias, they must be equal. `in_len` may not be

// zero.

//

// `counter[0]` is the initial 32-bit block counter, and the remainder is the

// 96-bit nonce. If the counter overflows, the output is undefined. The function

// will produce output, but the output may vary by machine and may not be

// self-consistent. (On some architectures, the assembly implements a mix of

// 64-bit and 32-bit counters.)

extern "C" void ChaCha20_ctr32_nohw(uint8_t *out, const uint8_t *in,

                                    size_t in_len, const uint32_t key[8],

                                    const uint32_t counter[4]);

#endif

BSSL_NAMESPACE_END

#endif  // OPENSSL_HEADER_CRYPTO_CHACHA_INTERNAL_H