#ifndef COSMOPOLITAN_THIRD_PARTY_ARGON2_ARGON2_H_
#define COSMOPOLITAN_THIRD_PARTY_ARGON2_ARGON2_H_
#include "libc/literal.h"

#define ARGON2_NO_THREADS

#if !(__ASSEMBLER__ + __LINKER__ + 0)
COSMOPOLITAN_C_START_

/*
 * Argon2 input parameter restrictions
 */

/* Minimum and maximum number of lanes (degree of parallelism) */
#define ARGON2_MIN_LANES UINT32_C(1)
#define ARGON2_MAX_LANES UINT32_C(0xFFFFFF)

/* Minimum and maximum number of threads */
#define ARGON2_MIN_THREADS UINT32_C(1)
#define ARGON2_MAX_THREADS UINT32_C(0xFFFFFF)

/* Number of synchronization points between lanes per pass */
#define ARGON2_SYNC_POINTS UINT32_C(4)

/* Minimum and maximum digest size in bytes */
#define ARGON2_MIN_OUTLEN UINT32_C(4)
#define ARGON2_MAX_OUTLEN UINT32_C(0xFFFFFFFF)

/* Minimum and maximum number of memory blocks (each of BLOCK_SIZE bytes) */
#define ARGON2_MIN_MEMORY (2 * ARGON2_SYNC_POINTS) /* 2 blocks per slice */

#define ARGON2_MIN(a, b) ((a) < (b) ? (a) : (b))
/* Max memory size is addressing-space/2, topping at 2^32 blocks (4 TB) */
#define ARGON2_MAX_MEMORY_BITS \
  ARGON2_MIN(UINT32_C(32), (sizeof(void *) * CHAR_BIT - 10 - 1))
#define ARGON2_MAX_MEMORY \
  ARGON2_MIN(UINT32_C(0xFFFFFFFF), UINT64_C(1) << ARGON2_MAX_MEMORY_BITS)

/* Minimum and maximum number of passes */
#define ARGON2_MIN_TIME UINT32_C(1)
#define ARGON2_MAX_TIME UINT32_C(0xFFFFFFFF)

/* Minimum and maximum password length in bytes */
#define ARGON2_MIN_PWD_LENGTH UINT32_C(0)
#define ARGON2_MAX_PWD_LENGTH UINT32_C(0xFFFFFFFF)

/* Minimum and maximum associated data length in bytes */
#define ARGON2_MIN_AD_LENGTH UINT32_C(0)
#define ARGON2_MAX_AD_LENGTH UINT32_C(0xFFFFFFFF)

/* Minimum and maximum salt length in bytes */
#define ARGON2_MIN_SALT_LENGTH UINT32_C(8)
#define ARGON2_MAX_SALT_LENGTH UINT32_C(0xFFFFFFFF)

/* Minimum and maximum key length in bytes */
#define ARGON2_MIN_SECRET UINT32_C(0)
#define ARGON2_MAX_SECRET UINT32_C(0xFFFFFFFF)

/* Flags to determine which fields are securely wiped (default = no wipe). */
#define ARGON2_DEFAULT_FLAGS       UINT32_C(0)
#define ARGON2_FLAG_CLEAR_PASSWORD (UINT32_C(1) << 0)
#define ARGON2_FLAG_CLEAR_SECRET   (UINT32_C(1) << 1)

/* Global flag to determine if we are wiping internal memory buffers. This flag
 * is defined in core.c and defaults to 1 (wipe internal memory). */
extern int FLAG_clear_internal_memory;

/* Error codes */
typedef enum Argon2_ErrorCodes {
  ARGON2_OK = 0,
  ARGON2_OUTPUT_PTR_NULL = -1,
  ARGON2_OUTPUT_TOO_SHORT = -2,
  ARGON2_OUTPUT_TOO_LONG = -3,
  ARGON2_PWD_TOO_SHORT = -4,
  ARGON2_PWD_TOO_LONG = -5,
  ARGON2_SALT_TOO_SHORT = -6,
  ARGON2_SALT_TOO_LONG = -7,
  ARGON2_AD_TOO_SHORT = -8,
  ARGON2_AD_TOO_LONG = -9,
  ARGON2_SECRET_TOO_SHORT = -10,
  ARGON2_SECRET_TOO_LONG = -11,
  ARGON2_TIME_TOO_SMALL = -12,
  ARGON2_TIME_TOO_LARGE = -13,
  ARGON2_MEMORY_TOO_LITTLE = -14,
  ARGON2_MEMORY_TOO_MUCH = -15,
  ARGON2_LANES_TOO_FEW = -16,
  ARGON2_LANES_TOO_MANY = -17,
  ARGON2_PWD_PTR_MISMATCH = -18,    /* NULL ptr with non-zero length */
  ARGON2_SALT_PTR_MISMATCH = -19,   /* NULL ptr with non-zero length */
  ARGON2_SECRET_PTR_MISMATCH = -20, /* NULL ptr with non-zero length */
  ARGON2_AD_PTR_MISMATCH = -21,     /* NULL ptr with non-zero length */
  ARGON2_MEMORY_ALLOCATION_ERROR = -22,
  ARGON2_FREE_MEMORY_CBK_NULL = -23,
  ARGON2_ALLOCATE_MEMORY_CBK_NULL = -24,
  ARGON2_INCORRECT_PARAMETER = -25,
  ARGON2_INCORRECT_TYPE = -26,
  ARGON2_OUT_PTR_MISMATCH = -27,
  ARGON2_THREADS_TOO_FEW = -28,
  ARGON2_THREADS_TOO_MANY = -29,
  ARGON2_MISSING_ARGS = -30,
  ARGON2_ENCODING_FAIL = -31,
  ARGON2_DECODING_FAIL = -32,
  ARGON2_THREAD_FAIL = -33,
  ARGON2_DECODING_LENGTH_FAIL = -34,
  ARGON2_VERIFY_MISMATCH = -35
} argon2_error_codes;

/* Memory allocator types --- for external allocation */
typedef int (*allocate_fptr)(uint8_t **memory, size_t bytes_to_allocate);
typedef void (*deallocate_fptr)(uint8_t *memory, size_t bytes_to_allocate);

/*
 *****
 * Context: structure to hold Argon2 inputs:
 *  output array and its length,
 *  password and its length,
 *  salt and its length,
 *  secret and its length,
 *  associated data and its length,
 *  number of passes, amount of used memory (in KBytes, can be rounded up a bit)
 *  number of parallel threads that will be run.
 * All the parameters above affect the output hash value.
 * Additionally, two function pointers can be provided to allocate and
 * deallocate the memory (if NULL, memory will be allocated internally).
 * Also, three flags indicate whether to erase password, secret as soon as they
 * are pre-hashed (and thus not needed anymore), and the entire memory
 *****
 * Simplest situation: you have output array out[8], password is stored in
 * pwd[32], salt is stored in salt[16], you do not have keys nor associated
 * data. You need to spend 1 GB of RAM and you run 5 passes of Argon2d with
 * 4 parallel lanes.
 * You want to erase the password, but you're OK with last pass not being
 * erased. You want to use the default memory allocator.
 * Then you initialize:
 Argon2_Context(out,8,pwd,32,salt,16,NULL,0,NULL,0,5,1<<20,4,4,NULL,NULL,true,false,false,false)
 */
typedef struct Argon2_Context {
  uint8_t *out;               /* output array */
  uint32_t outlen;            /* digest length */
  uint8_t *pwd;               /* password array */
  uint32_t pwdlen;            /* password length */
  uint8_t *salt;              /* salt array */
  uint32_t saltlen;           /* salt length */
  uint8_t *secret;            /* key array */
  uint32_t secretlen;         /* key length */
  uint8_t *ad;                /* associated data array */
  uint32_t adlen;             /* associated data length */
  uint32_t t_cost;            /* number of passes */
  uint32_t m_cost;            /* amount of memory requested (KB) */
  uint32_t lanes;             /* number of lanes */
  uint32_t threads;           /* maximum number of threads */
  uint32_t version;           /* version number */
  allocate_fptr allocate_cbk; /* pointer to memory allocator */
  deallocate_fptr free_cbk;   /* pointer to memory deallocator */
  uint32_t flags;             /* array of bool options */
} argon2_context;

/* Argon2 primitive type */
typedef enum Argon2_type {
  Argon2_d = 0,
  Argon2_i = 1,
  Argon2_id = 2
} argon2_type;

/* Version of the algorithm */
typedef enum Argon2_version {
  ARGON2_VERSION_10 = 0x10,
  ARGON2_VERSION_13 = 0x13,
  ARGON2_VERSION_NUMBER = ARGON2_VERSION_13
} argon2_version;

int argon2i_hash_encoded(const uint32_t, const uint32_t, const uint32_t,
                         const void *, const size_t, const void *, const size_t,
                         const size_t, char *, const size_t);
int argon2i_hash_raw(const uint32_t, const uint32_t, const uint32_t,
                     const void *, const size_t, const void *, const size_t,
                     void *, const size_t);
int argon2d_hash_encoded(const uint32_t, const uint32_t, const uint32_t,
                         const void *, const size_t, const void *, const size_t,
                         const size_t, char *, const size_t);
int argon2d_hash_raw(const uint32_t, const uint32_t, const uint32_t,
                     const void *, const size_t, const void *, const size_t,
                     void *, const size_t);
int argon2id_hash_encoded(const uint32_t, const uint32_t, const uint32_t,
                          const void *, const size_t, const void *,
                          const size_t, const size_t, char *, const size_t);
int argon2id_hash_raw(const uint32_t, const uint32_t, const uint32_t,
                      const void *, const size_t, const void *, const size_t,
                      void *, const size_t);
int argon2_hash(const uint32_t, const uint32_t, const uint32_t, const void *,
                const size_t, const void *, const size_t, void *, const size_t,
                char *, const size_t, argon2_type, const uint32_t);

const char *argon2_type2string(argon2_type, int);
int argon2_ctx(argon2_context *, argon2_type);
int argon2i_verify(const char *, const void *, const size_t);
int argon2d_verify(const char *, const void *, const size_t);
int argon2id_verify(const char *, const void *, const size_t);
int argon2_verify(const char *, const void *, const size_t, argon2_type);
int argon2d_ctx(argon2_context *);
int argon2i_ctx(argon2_context *);
int argon2id_ctx(argon2_context *);
int argon2d_verify_ctx(argon2_context *, const char *);
int argon2i_verify_ctx(argon2_context *, const char *);
int argon2id_verify_ctx(argon2_context *, const char *);
int argon2_verify_ctx(argon2_context *, const char *, argon2_type);
const char *argon2_error_message(int);
size_t argon2_encodedlen(uint32_t, uint32_t, uint32_t, uint32_t, uint32_t,
                         argon2_type);

COSMOPOLITAN_C_END_
#endif /* !(__ASSEMBLER__ + __LINKER__ + 0) */
#endif /* COSMOPOLITAN_THIRD_PARTY_ARGON2_ARGON2_H_ */
