/* ====================================================================
 * Copyright (c) 2008 The OpenSSL Project.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *
 * 3. All advertising materials mentioning features or use of this
 *    software must display the following acknowledgment:
 *    "This product includes software developed by the OpenSSL Project
 *    for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
 *
 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
 *    endorse or promote products derived from this software without
 *    prior written permission. For written permission, please contact
 *    openssl-core@openssl.org.
 *
 * 5. Products derived from this software may not be called "OpenSSL"
 *    nor may "OpenSSL" appear in their names without prior written
 *    permission of the OpenSSL Project.
 *
 * 6. Redistributions of any form whatsoever must retain the following
 *    acknowledgment:
 *    "This product includes software developed by the OpenSSL Project
 *    for use in the OpenSSL Toolkit (http://www.openssl.org/)"
 *
 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
 * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE OpenSSL PROJECT OR
 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED
 * OF THE POSSIBILITY OF SUCH DAMAGE.
 * ==================================================================== */

#ifndef OPENSSL_HEADER_MODES_INTERNAL_H
#define OPENSSL_HEADER_MODES_INTERNAL_H

#include <openssl/base.h>

#include <string.h>

#include "../internal.h"

#if defined(__cplusplus)
extern "C" {
#endif


#define asm __asm__

#define STRICT_ALIGNMENT 1
#if defined(OPENSSL_X86_64) || defined(OPENSSL_X86) || defined(OPENSSL_AARCH64)
#undef STRICT_ALIGNMENT
#define STRICT_ALIGNMENT 0
#endif

#if defined(__GNUC__) && __GNUC__ >= 2
static inline uint32_t CRYPTO_bswap4(uint32_t x) {
  return __builtin_bswap32(x);
}

static inline uint64_t CRYPTO_bswap8(uint64_t x) {
  return __builtin_bswap64(x);
}
#elif defined(_MSC_VER)
OPENSSL_MSVC_PRAGMA(warning(push, 3))
#include <intrin.h>
OPENSSL_MSVC_PRAGMA(warning(pop))
#pragma intrinsic(_byteswap_uint64, _byteswap_ulong)
static inline uint32_t CRYPTO_bswap4(uint32_t x) {
  return _byteswap_ulong(x);
}

static inline uint64_t CRYPTO_bswap8(uint64_t x) {
  return _byteswap_uint64(x);
}
#else
static inline uint32_t CRYPTO_bswap4(uint32_t x) {
  x = (x >> 16) | (x << 16);
  x = ((x & 0xff00ff00) >> 8) | ((x & 0x00ff00ff) << 8);
  return x;
}

static inline uint64_t CRYPTO_bswap8(uint64_t x) {
  return CRYPTO_bswap4(x >> 32) | (((uint64_t)CRYPTO_bswap4(x)) << 32);
}
#endif

static inline uint32_t GETU32(const void *in) {
  uint32_t v;
  OPENSSL_memcpy(&v, in, sizeof(v));
  return CRYPTO_bswap4(v);
}

static inline void PUTU32(void *out, uint32_t v) {
  v = CRYPTO_bswap4(v);
  OPENSSL_memcpy(out, &v, sizeof(v));
}

static inline uint32_t GETU32_aligned(const void *in) {
  const char *alias = (const char *) in;
  return CRYPTO_bswap4(*((const uint32_t *) alias));
}

static inline void PUTU32_aligned(void *in, uint32_t v) {
  char *alias = (char *) in;
  *((uint32_t *) alias) = CRYPTO_bswap4(v);
}

/* block128_f is the type of a 128-bit, block cipher. */
typedef void (*block128_f)(const uint8_t in[16], uint8_t out[16],
                           const void *key);

/* GCM definitions */
typedef struct { uint64_t hi,lo; } u128;

/* gmult_func multiplies |Xi| by the GCM key and writes the result back to
 * |Xi|. */
typedef void (*gmult_func)(uint64_t Xi[2], const u128 Htable[16]);

/* ghash_func repeatedly multiplies |Xi| by the GCM key and adds in blocks from
 * |inp|. The result is written back to |Xi| and the |len| argument must be a
 * multiple of 16. */
typedef void (*ghash_func)(uint64_t Xi[2], const u128 Htable[16],
                           const uint8_t *inp, size_t len);

/* This differs from upstream's |gcm128_context| in that it does not have the
 * |key| pointer, in order to make it |memcpy|-friendly. Rather the key is
 * passed into each call that needs it. */
struct gcm128_context {
  /* Following 6 names follow names in GCM specification */
  union {
    uint64_t u[2];
    uint32_t d[4];
    uint8_t c[16];
    size_t t[16 / sizeof(size_t)];
  } Yi, EKi, EK0, len, Xi;

  u128 Htable[16];
  gmult_func gmult;
  ghash_func ghash;

  unsigned int mres, ares;
  block128_f block;
};

#if defined(OPENSSL_X86) || defined(OPENSSL_X86_64)
/* crypto_gcm_clmul_enabled returns one if the CLMUL implementation of GCM is
 * used. */
int crypto_gcm_clmul_enabled(void);
#endif


/* CTR. */

/* ctr128_f is the type of a function that performs CTR-mode encryption. */
typedef void (*ctr128_f)(const uint8_t *in, uint8_t *out, size_t blocks,
                         const void *key, const uint8_t ivec[16]);

/* CRYPTO_ctr128_encrypt encrypts (or decrypts, it's the same in CTR mode)
 * |len| bytes from |in| to |out| using |block| in counter mode. There's no
 * requirement that |len| be a multiple of any value and any partial blocks are
 * stored in |ecount_buf| and |*num|, which must be zeroed before the initial
 * call. The counter is a 128-bit, big-endian value in |ivec| and is
 * incremented by this function. */
void CRYPTO_ctr128_encrypt(const uint8_t *in, uint8_t *out, size_t len,
                           const void *key, uint8_t ivec[16],
                           uint8_t ecount_buf[16], unsigned *num,
                           block128_f block);

/* CRYPTO_ctr128_encrypt_ctr32 acts like |CRYPTO_ctr128_encrypt| but takes
 * |ctr|, a function that performs CTR mode but only deals with the lower 32
 * bits of the counter. This is useful when |ctr| can be an optimised
 * function. */
void CRYPTO_ctr128_encrypt_ctr32(const uint8_t *in, uint8_t *out, size_t len,
                                 const void *key, uint8_t ivec[16],
                                 uint8_t ecount_buf[16], unsigned *num,
                                 ctr128_f ctr);

#if !defined(OPENSSL_NO_ASM) && \
    (defined(OPENSSL_X86) || defined(OPENSSL_X86_64))
void aesni_ctr32_encrypt_blocks(const uint8_t *in, uint8_t *out, size_t blocks,
                                const void *key, const uint8_t *ivec);
#endif


/* GCM.
 *
 * This API differs from the upstream API slightly. The |GCM128_CONTEXT| does
 * not have a |key| pointer that points to the key as upstream's version does.
 * Instead, every function takes a |key| parameter. This way |GCM128_CONTEXT|
 * can be safely copied. */

typedef struct gcm128_context GCM128_CONTEXT;

/* CRYPTO_ghash_init writes a precomputed table of powers of |gcm_key| to
 * |out_table| and sets |*out_mult| and |*out_hash| to (potentially hardware
 * accelerated) functions for performing operations in the GHASH field. */
void CRYPTO_ghash_init(gmult_func *out_mult, ghash_func *out_hash,
                       u128 out_table[16], const uint8_t *gcm_key);

/* CRYPTO_gcm128_init initialises |ctx| to use |block| (typically AES) with
 * the given key. */
OPENSSL_EXPORT void CRYPTO_gcm128_init(GCM128_CONTEXT *ctx, const void *key,
                                       block128_f block);

/* CRYPTO_gcm128_setiv sets the IV (nonce) for |ctx|. The |key| must be the
 * same key that was passed to |CRYPTO_gcm128_init|. */
OPENSSL_EXPORT void CRYPTO_gcm128_setiv(GCM128_CONTEXT *ctx, const void *key,
                                        const uint8_t *iv, size_t iv_len);

/* CRYPTO_gcm128_aad sets the authenticated data for an instance of GCM.
 * This must be called before and data is encrypted. It returns one on success
 * and zero otherwise. */
OPENSSL_EXPORT int CRYPTO_gcm128_aad(GCM128_CONTEXT *ctx, const uint8_t *aad,
                                     size_t len);

/* CRYPTO_gcm128_encrypt encrypts |len| bytes from |in| to |out|. The |key|
 * must be the same key that was passed to |CRYPTO_gcm128_init|. It returns one
 * on success and zero otherwise. */
OPENSSL_EXPORT int CRYPTO_gcm128_encrypt(GCM128_CONTEXT *ctx, const void *key,
                                         const uint8_t *in, uint8_t *out,
                                         size_t len);

/* CRYPTO_gcm128_decrypt decrypts |len| bytes from |in| to |out|. The |key|
 * must be the same key that was passed to |CRYPTO_gcm128_init|. It returns one
 * on success and zero otherwise. */
OPENSSL_EXPORT int CRYPTO_gcm128_decrypt(GCM128_CONTEXT *ctx, const void *key,
                                         const uint8_t *in, uint8_t *out,
                                         size_t len);

/* CRYPTO_gcm128_encrypt_ctr32 encrypts |len| bytes from |in| to |out| using
 * a CTR function that only handles the bottom 32 bits of the nonce, like
 * |CRYPTO_ctr128_encrypt_ctr32|. The |key| must be the same key that was
 * passed to |CRYPTO_gcm128_init|. It returns one on success and zero
 * otherwise. */
OPENSSL_EXPORT int CRYPTO_gcm128_encrypt_ctr32(GCM128_CONTEXT *ctx,
                                               const void *key,
                                               const uint8_t *in, uint8_t *out,
                                               size_t len, ctr128_f stream);

/* CRYPTO_gcm128_decrypt_ctr32 decrypts |len| bytes from |in| to |out| using
 * a CTR function that only handles the bottom 32 bits of the nonce, like
 * |CRYPTO_ctr128_encrypt_ctr32|. The |key| must be the same key that was
 * passed to |CRYPTO_gcm128_init|. It returns one on success and zero
 * otherwise. */
OPENSSL_EXPORT int CRYPTO_gcm128_decrypt_ctr32(GCM128_CONTEXT *ctx,
                                               const void *key,
                                               const uint8_t *in, uint8_t *out,
                                               size_t len, ctr128_f stream);

/* CRYPTO_gcm128_finish calculates the authenticator and compares it against
 * |len| bytes of |tag|. It returns one on success and zero otherwise. */
OPENSSL_EXPORT int CRYPTO_gcm128_finish(GCM128_CONTEXT *ctx, const uint8_t *tag,
                                        size_t len);

/* CRYPTO_gcm128_tag calculates the authenticator and copies it into |tag|.
 * The minimum of |len| and 16 bytes are copied into |tag|. */
OPENSSL_EXPORT void CRYPTO_gcm128_tag(GCM128_CONTEXT *ctx, uint8_t *tag,
                                      size_t len);


/* CBC. */

/* cbc128_f is the type of a function that performs CBC-mode encryption. */
typedef void (*cbc128_f)(const uint8_t *in, uint8_t *out, size_t len,
                         const void *key, uint8_t ivec[16], int enc);

/* CRYPTO_cbc128_encrypt encrypts |len| bytes from |in| to |out| using the
 * given IV and block cipher in CBC mode. The input need not be a multiple of
 * 128 bits long, but the output will round up to the nearest 128 bit multiple,
 * zero padding the input if needed. The IV will be updated on return. */
void CRYPTO_cbc128_encrypt(const uint8_t *in, uint8_t *out, size_t len,
                           const void *key, uint8_t ivec[16], block128_f block);

/* CRYPTO_cbc128_decrypt decrypts |len| bytes from |in| to |out| using the
 * given IV and block cipher in CBC mode. If |len| is not a multiple of 128
 * bits then only that many bytes will be written, but a multiple of 128 bits
 * is always read from |in|. The IV will be updated on return. */
void CRYPTO_cbc128_decrypt(const uint8_t *in, uint8_t *out, size_t len,
                           const void *key, uint8_t ivec[16], block128_f block);


/* OFB. */

/* CRYPTO_ofb128_encrypt encrypts (or decrypts, it's the same with OFB mode)
 * |len| bytes from |in| to |out| using |block| in OFB mode. There's no
 * requirement that |len| be a multiple of any value and any partial blocks are
 * stored in |ivec| and |*num|, the latter must be zero before the initial
 * call. */
void CRYPTO_ofb128_encrypt(const uint8_t *in, uint8_t *out,
                           size_t len, const void *key, uint8_t ivec[16],
                           unsigned *num, block128_f block);


/* CFB. */

/* CRYPTO_cfb128_encrypt encrypts (or decrypts, if |enc| is zero) |len| bytes
 * from |in| to |out| using |block| in CFB mode. There's no requirement that
 * |len| be a multiple of any value and any partial blocks are stored in |ivec|
 * and |*num|, the latter must be zero before the initial call. */
void CRYPTO_cfb128_encrypt(const uint8_t *in, uint8_t *out, size_t len,
                           const void *key, uint8_t ivec[16], unsigned *num,
                           int enc, block128_f block);

/* CRYPTO_cfb128_8_encrypt encrypts (or decrypts, if |enc| is zero) |len| bytes
 * from |in| to |out| using |block| in CFB-8 mode. Prior to the first call
 * |num| should be set to zero. */
void CRYPTO_cfb128_8_encrypt(const uint8_t *in, uint8_t *out, size_t len,
                             const void *key, uint8_t ivec[16], unsigned *num,
                             int enc, block128_f block);

/* CRYPTO_cfb128_1_encrypt encrypts (or decrypts, if |enc| is zero) |len| bytes
 * from |in| to |out| using |block| in CFB-1 mode. Prior to the first call
 * |num| should be set to zero. */
void CRYPTO_cfb128_1_encrypt(const uint8_t *in, uint8_t *out, size_t bits,
                             const void *key, uint8_t ivec[16], unsigned *num,
                             int enc, block128_f block);

size_t CRYPTO_cts128_encrypt_block(const uint8_t *in, uint8_t *out, size_t len,
                                   const void *key, uint8_t ivec[16],
                                   block128_f block);


/* POLYVAL.
 *
 * POLYVAL is a polynomial authenticator that operates over a field very
 * similar to the one that GHASH uses. See
 * https://tools.ietf.org/html/draft-irtf-cfrg-gcmsiv-02#section-3. */

typedef union {
  uint64_t u[2];
  uint8_t c[16];
} polyval_block;

struct polyval_ctx {
  polyval_block S;
  u128 Htable[16];
  gmult_func gmult;
  ghash_func ghash;
};

/* CRYPTO_POLYVAL_init initialises |ctx| using |key|. */
void CRYPTO_POLYVAL_init(struct polyval_ctx *ctx, const uint8_t key[16]);

/* CRYPTO_POLYVAL_update_blocks updates the accumulator in |ctx| given the
 * blocks from |in|. Only a whole number of blocks can be processed so |in_len|
 * must be a multiple of 16. */
void CRYPTO_POLYVAL_update_blocks(struct polyval_ctx *ctx, const uint8_t *in,
                                  size_t in_len);

/* CRYPTO_POLYVAL_finish writes the accumulator from |ctx| to |out|. */
void CRYPTO_POLYVAL_finish(const struct polyval_ctx *ctx, uint8_t out[16]);


#if defined(__cplusplus)
} /* extern C */
#endif

#endif /* OPENSSL_HEADER_MODES_INTERNAL_H */