/*
* 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.
*/
#include "win32.h"
#include "runtime.h"
#include <wincrypt.h>
#include <strsafe.h>
#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
static git_hash_prov hash_prov = {0};
/* Hash initialization */
/* Initialize CNG, if available */
GIT_INLINE(int) hash_cng_prov_init(void)
{
char dll_path[MAX_PATH];
DWORD dll_path_len, size_len;
/* Only use CNG on Windows 2008 / Vista SP1 or better (Windows 6.0 SP1) */
if (!git_has_win32_version(6, 0, 1)) {
git_error_set(GIT_ERROR_SHA1, "CryptoNG is not supported on this platform");
return -1;
}
/* Load bcrypt.dll explicitly from the system directory */
if ((dll_path_len = GetSystemDirectory(dll_path, MAX_PATH)) == 0 ||
dll_path_len > MAX_PATH ||
StringCchCat(dll_path, MAX_PATH, "\\") < 0 ||
StringCchCat(dll_path, MAX_PATH, GIT_HASH_CNG_DLL_NAME) < 0 ||
(hash_prov.prov.cng.dll = LoadLibrary(dll_path)) == NULL) {
git_error_set(GIT_ERROR_SHA1, "CryptoNG library could not be loaded");
return -1;
}
/* Load the function addresses */
if ((hash_prov.prov.cng.open_algorithm_provider = (hash_win32_cng_open_algorithm_provider_fn)GetProcAddress(hash_prov.prov.cng.dll, "BCryptOpenAlgorithmProvider")) == NULL ||
(hash_prov.prov.cng.get_property = (hash_win32_cng_get_property_fn)GetProcAddress(hash_prov.prov.cng.dll, "BCryptGetProperty")) == NULL ||
(hash_prov.prov.cng.create_hash = (hash_win32_cng_create_hash_fn)GetProcAddress(hash_prov.prov.cng.dll, "BCryptCreateHash")) == NULL ||
(hash_prov.prov.cng.finish_hash = (hash_win32_cng_finish_hash_fn)GetProcAddress(hash_prov.prov.cng.dll, "BCryptFinishHash")) == NULL ||
(hash_prov.prov.cng.hash_data = (hash_win32_cng_hash_data_fn)GetProcAddress(hash_prov.prov.cng.dll, "BCryptHashData")) == NULL ||
(hash_prov.prov.cng.destroy_hash = (hash_win32_cng_destroy_hash_fn)GetProcAddress(hash_prov.prov.cng.dll, "BCryptDestroyHash")) == NULL ||
(hash_prov.prov.cng.close_algorithm_provider = (hash_win32_cng_close_algorithm_provider_fn)GetProcAddress(hash_prov.prov.cng.dll, "BCryptCloseAlgorithmProvider")) == NULL) {
FreeLibrary(hash_prov.prov.cng.dll);
git_error_set(GIT_ERROR_OS, "CryptoNG functions could not be loaded");
return -1;
}
/* Load the SHA1 algorithm */
if (hash_prov.prov.cng.open_algorithm_provider(&hash_prov.prov.cng.handle, GIT_HASH_CNG_HASH_TYPE, NULL, GIT_HASH_CNG_HASH_REUSABLE) < 0) {
FreeLibrary(hash_prov.prov.cng.dll);
git_error_set(GIT_ERROR_OS, "algorithm provider could not be initialized");
return -1;
}
/* Get storage space for the hash object */
if (hash_prov.prov.cng.get_property(hash_prov.prov.cng.handle, GIT_HASH_CNG_HASH_OBJECT_LEN, (PBYTE)&hash_prov.prov.cng.hash_object_size, sizeof(DWORD), &size_len, 0) < 0) {
hash_prov.prov.cng.close_algorithm_provider(hash_prov.prov.cng.handle, 0);
FreeLibrary(hash_prov.prov.cng.dll);
git_error_set(GIT_ERROR_OS, "algorithm handle could not be found");
return -1;
}
hash_prov.type = CNG;
return 0;
}
GIT_INLINE(void) hash_cng_prov_shutdown(void)
{
hash_prov.prov.cng.close_algorithm_provider(hash_prov.prov.cng.handle, 0);
FreeLibrary(hash_prov.prov.cng.dll);
hash_prov.type = INVALID;
}
/* Initialize CryptoAPI */
GIT_INLINE(int) hash_cryptoapi_prov_init()
{
if (!CryptAcquireContext(&hash_prov.prov.cryptoapi.handle, NULL, 0, PROV_RSA_FULL, CRYPT_VERIFYCONTEXT)) {
git_error_set(GIT_ERROR_OS, "legacy hash context could not be started");
return -1;
}
hash_prov.type = CRYPTOAPI;
return 0;
}
GIT_INLINE(void) hash_cryptoapi_prov_shutdown(void)
{
CryptReleaseContext(hash_prov.prov.cryptoapi.handle, 0);
hash_prov.type = INVALID;
}
static void sha1_shutdown(void)
{
if (hash_prov.type == CNG)
hash_cng_prov_shutdown();
else if(hash_prov.type == CRYPTOAPI)
hash_cryptoapi_prov_shutdown();
}
int git_hash_sha1_global_init(void)
{
int error = 0;
if (hash_prov.type != INVALID)
return 0;
if ((error = hash_cng_prov_init()) < 0)
error = hash_cryptoapi_prov_init();
if (!error)
error = git_runtime_shutdown_register(sha1_shutdown);
return error;
}
/* CryptoAPI: available in Windows XP and newer */
GIT_INLINE(int) hash_ctx_cryptoapi_init(git_hash_sha1_ctx *ctx)
{
ctx->type = CRYPTOAPI;
ctx->prov = &hash_prov;
return git_hash_sha1_init(ctx);
}
GIT_INLINE(int) hash_cryptoapi_init(git_hash_sha1_ctx *ctx)
{
if (ctx->ctx.cryptoapi.valid)
CryptDestroyHash(ctx->ctx.cryptoapi.hash_handle);
if (!CryptCreateHash(ctx->prov->prov.cryptoapi.handle, CALG_SHA1, 0, 0, &ctx->ctx.cryptoapi.hash_handle)) {
ctx->ctx.cryptoapi.valid = 0;
git_error_set(GIT_ERROR_OS, "legacy hash implementation could not be created");
return -1;
}
ctx->ctx.cryptoapi.valid = 1;
return 0;
}
GIT_INLINE(int) hash_cryptoapi_update(git_hash_sha1_ctx *ctx, const void *_data, size_t len)
{
const BYTE *data = (BYTE *)_data;
GIT_ASSERT(ctx->ctx.cryptoapi.valid);
while (len > 0) {
DWORD chunk = (len > MAXDWORD) ? MAXDWORD : (DWORD)len;
if (!CryptHashData(ctx->ctx.cryptoapi.hash_handle, data, chunk, 0)) {
git_error_set(GIT_ERROR_OS, "legacy hash data could not be updated");
return -1;
}
data += chunk;
len -= chunk;
}
return 0;
}
GIT_INLINE(int) hash_cryptoapi_final(git_oid *out, git_hash_sha1_ctx *ctx)
{
DWORD len = 20;
int error = 0;
GIT_ASSERT(ctx->ctx.cryptoapi.valid);
if (!CryptGetHashParam(ctx->ctx.cryptoapi.hash_handle, HP_HASHVAL, out->id, &len, 0)) {
git_error_set(GIT_ERROR_OS, "legacy hash data could not be finished");
error = -1;
}
CryptDestroyHash(ctx->ctx.cryptoapi.hash_handle);
ctx->ctx.cryptoapi.valid = 0;
return error;
}
GIT_INLINE(void) hash_ctx_cryptoapi_cleanup(git_hash_sha1_ctx *ctx)
{
if (ctx->ctx.cryptoapi.valid)
CryptDestroyHash(ctx->ctx.cryptoapi.hash_handle);
}
/* CNG: Available in Windows Server 2008 and newer */
GIT_INLINE(int) hash_ctx_cng_init(git_hash_sha1_ctx *ctx)
{
if ((ctx->ctx.cng.hash_object = git__malloc(hash_prov.prov.cng.hash_object_size)) == NULL)
return -1;
if (hash_prov.prov.cng.create_hash(hash_prov.prov.cng.handle, &ctx->ctx.cng.hash_handle, ctx->ctx.cng.hash_object, hash_prov.prov.cng.hash_object_size, NULL, 0, 0) < 0) {
git__free(ctx->ctx.cng.hash_object);
git_error_set(GIT_ERROR_OS, "hash implementation could not be created");
return -1;
}
ctx->type = CNG;
ctx->prov = &hash_prov;
return 0;
}
GIT_INLINE(int) hash_cng_init(git_hash_sha1_ctx *ctx)
{
BYTE hash[GIT_OID_RAWSZ];
if (!ctx->ctx.cng.updated)
return 0;
/* CNG needs to be finished to restart */
if (ctx->prov->prov.cng.finish_hash(ctx->ctx.cng.hash_handle, hash, GIT_OID_RAWSZ, 0) < 0) {
git_error_set(GIT_ERROR_OS, "hash implementation could not be finished");
return -1;
}
ctx->ctx.cng.updated = 0;
return 0;
}
GIT_INLINE(int) hash_cng_update(git_hash_sha1_ctx *ctx, const void *_data, size_t len)
{
PBYTE data = (PBYTE)_data;
while (len > 0) {
ULONG chunk = (len > ULONG_MAX) ? ULONG_MAX : (ULONG)len;
if (ctx->prov->prov.cng.hash_data(ctx->ctx.cng.hash_handle, data, chunk, 0) < 0) {
git_error_set(GIT_ERROR_OS, "hash could not be updated");
return -1;
}
data += chunk;
len -= chunk;
}
return 0;
}
GIT_INLINE(int) hash_cng_final(git_oid *out, git_hash_sha1_ctx *ctx)
{
if (ctx->prov->prov.cng.finish_hash(ctx->ctx.cng.hash_handle, out->id, GIT_OID_RAWSZ, 0) < 0) {
git_error_set(GIT_ERROR_OS, "hash could not be finished");
return -1;
}
ctx->ctx.cng.updated = 0;
return 0;
}
GIT_INLINE(void) hash_ctx_cng_cleanup(git_hash_sha1_ctx *ctx)
{
ctx->prov->prov.cng.destroy_hash(ctx->ctx.cng.hash_handle);
git__free(ctx->ctx.cng.hash_object);
}
/* Indirection between CryptoAPI and CNG */
int git_hash_sha1_ctx_init(git_hash_sha1_ctx *ctx)
{
int error = 0;
GIT_ASSERT_ARG(ctx);
/*
* When compiled with GIT_THREADS, the global hash_prov data is
* initialized with git_libgit2_init. Otherwise, it must be initialized
* at first use.
*/
if (hash_prov.type == INVALID && (error = git_hash_sha1_global_init()) < 0)
return error;
memset(ctx, 0x0, sizeof(git_hash_sha1_ctx));
return (hash_prov.type == CNG) ? hash_ctx_cng_init(ctx) : hash_ctx_cryptoapi_init(ctx);
}
int git_hash_sha1_init(git_hash_sha1_ctx *ctx)
{
GIT_ASSERT_ARG(ctx);
GIT_ASSERT_ARG(ctx->type);
return (ctx->type == CNG) ? hash_cng_init(ctx) : hash_cryptoapi_init(ctx);
}
int git_hash_sha1_update(git_hash_sha1_ctx *ctx, const void *data, size_t len)
{
GIT_ASSERT_ARG(ctx);
GIT_ASSERT_ARG(ctx->type);
return (ctx->type == CNG) ? hash_cng_update(ctx, data, len) : hash_cryptoapi_update(ctx, data, len);
}
int git_hash_sha1_final(git_oid *out, git_hash_sha1_ctx *ctx)
{
GIT_ASSERT_ARG(ctx);
GIT_ASSERT_ARG(ctx->type);
return (ctx->type == CNG) ? hash_cng_final(out, ctx) : hash_cryptoapi_final(out, ctx);
}
void git_hash_sha1_ctx_cleanup(git_hash_sha1_ctx *ctx)
{
if (!ctx)
return;
else if (ctx->type == CNG)
hash_ctx_cng_cleanup(ctx);
else if(ctx->type == CRYPTOAPI)
hash_ctx_cryptoapi_cleanup(ctx);
}
