/*

 * Copyright (C) the libgit2 contributors. All rights reserved.

 *

 * This file is part of libgit2, distributed under the GNU GPL v2 with

 * a Linking Exception. For full terms see the included COPYING file.

 */

#ifndef INCLUDE_hash_win32_h__

#define INCLUDE_hash_win32_h__

#include "common.h"

#include "hash.h"

#include <wincrypt.h>

#include <strsafe.h>

enum hash_win32_prov_type {

	INVALID = 0,

	CRYPTOAPI,

	CNG

};

/*

 * CryptoAPI is available for hashing on Windows XP and newer.

 */

struct hash_cryptoapi_prov {

	HCRYPTPROV handle;

};

/*

 * CNG (bcrypt.dll) is significantly more performant than CryptoAPI and is

 * preferred, however it is only available on Windows 2008 and newer and

 * must therefore be dynamically loaded, and we must inline constants that

 * would not exist when building in pre-Windows 2008 environments.

 */

#define GIT_HASH_CNG_DLL_NAME           "bcrypt.dll"

/* BCRYPT_SHA1_ALGORITHM */

#define GIT_HASH_CNG_HASH_TYPE          L"SHA1"

/* BCRYPT_OBJECT_LENGTH */

#define GIT_HASH_CNG_HASH_OBJECT_LEN    L"ObjectLength"

/* BCRYPT_HASH_REUSEABLE_FLAGS */

#define GIT_HASH_CNG_HASH_REUSABLE      0x00000020

/* Function declarations for CNG */

typedef NTSTATUS (WINAPI *hash_win32_cng_open_algorithm_provider_fn)(

	HANDLE /* BCRYPT_ALG_HANDLE */ *phAlgorithm,

	LPCWSTR pszAlgId,

	LPCWSTR pszImplementation,

	DWORD dwFlags);

typedef NTSTATUS (WINAPI *hash_win32_cng_get_property_fn)(

	HANDLE /* BCRYPT_HANDLE */ hObject,

	LPCWSTR pszProperty,

	PUCHAR pbOutput,

	ULONG cbOutput,

	ULONG *pcbResult,

	ULONG dwFlags);

typedef NTSTATUS (WINAPI *hash_win32_cng_create_hash_fn)(

	HANDLE /* BCRYPT_ALG_HANDLE */ hAlgorithm,

	HANDLE /* BCRYPT_HASH_HANDLE */ *phHash,

	PUCHAR pbHashObject, ULONG cbHashObject,

	PUCHAR pbSecret,

	ULONG cbSecret,

	ULONG dwFlags);

typedef NTSTATUS (WINAPI *hash_win32_cng_finish_hash_fn)(

	HANDLE /* BCRYPT_HASH_HANDLE */ hHash,

	PUCHAR pbOutput,

	ULONG cbOutput,

	ULONG dwFlags);

typedef NTSTATUS (WINAPI *hash_win32_cng_hash_data_fn)(

	HANDLE /* BCRYPT_HASH_HANDLE */ hHash,

	PUCHAR pbInput,

	ULONG cbInput,

	ULONG dwFlags);

typedef NTSTATUS (WINAPI *hash_win32_cng_destroy_hash_fn)(

	HANDLE /* BCRYPT_HASH_HANDLE */ hHash);

typedef NTSTATUS (WINAPI *hash_win32_cng_close_algorithm_provider_fn)(

	HANDLE /* BCRYPT_ALG_HANDLE */ hAlgorithm,

	ULONG dwFlags);

struct hash_cng_prov {

	/* DLL for CNG */

	HINSTANCE dll;

	/* Function pointers for CNG */

	hash_win32_cng_open_algorithm_provider_fn open_algorithm_provider;

	hash_win32_cng_get_property_fn get_property;

	hash_win32_cng_create_hash_fn create_hash;

	hash_win32_cng_finish_hash_fn finish_hash;

	hash_win32_cng_hash_data_fn hash_data;

	hash_win32_cng_destroy_hash_fn destroy_hash;

	hash_win32_cng_close_algorithm_provider_fn close_algorithm_provider;

	HANDLE /* BCRYPT_ALG_HANDLE */ handle;

	DWORD hash_object_size;

};

struct git_hash_prov {

	enum hash_win32_prov_type type;

	union {

		struct hash_cryptoapi_prov cryptoapi;

		struct hash_cng_prov cng;

	} prov;

};

/* Hash contexts */

struct hash_cryptoapi_ctx {

	bool valid;

	HCRYPTHASH hash_handle;

};

struct hash_cng_ctx {

	bool updated;

	HANDLE /* BCRYPT_HASH_HANDLE */ hash_handle;

	PBYTE hash_object;

};

struct git_hash_ctx {

	enum hash_win32_prov_type type;

	git_hash_prov *prov;

	union {

		struct hash_cryptoapi_ctx cryptoapi;

		struct hash_cng_ctx cng;

	} ctx;

};

#endif /* INCLUDE_hash_openssl_h__ */