hash_win32.c 7.71 KB
Newer Older
1
/*
Edward Thomson committed
2
 * Copyright (C) the libgit2 contributors. All rights reserved.
3 4 5 6 7
 *
 * This file is part of libgit2, distributed under the GNU GPL v2 with
 * a Linking Exception. For full terms see the included COPYING file.
 */

8 9
#include "hash_win32.h"

10 11 12 13 14 15
#include "global.h"
#include "hash.h"

#include <wincrypt.h>
#include <strsafe.h>

16 17 18 19
static struct git_hash_prov hash_prov = {0};

/* Hash initialization */

20
/* Initialize CNG, if available */
21
GIT_INLINE(int) hash_cng_prov_init(void)
22 23 24 25 26
{
	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) */
27
	if (!git_has_win32_version(6, 0, 1))
28 29 30
		return -1;

	/* Load bcrypt.dll explicitly from the system directory */
31 32
	if ((dll_path_len = GetSystemDirectory(dll_path, MAX_PATH)) == 0 ||
		dll_path_len > MAX_PATH ||
33 34
		StringCchCat(dll_path, MAX_PATH, "\\") < 0 ||
		StringCchCat(dll_path, MAX_PATH, GIT_HASH_CNG_DLL_NAME) < 0 ||
35
		(hash_prov.prov.cng.dll = LoadLibrary(dll_path)) == NULL)
36 37 38
		return -1;

	/* Load the function addresses */
39 40 41 42 43 44 45 46
	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);
47 48 49 50
		return -1;
	}

	/* Load the SHA1 algorithm */
51 52
	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);
53 54 55 56
		return -1;
	}

	/* Get storage space for the hash object */
57 58 59
	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);
60 61 62
		return -1;
	}

63
	hash_prov.type = CNG;
64 65 66
	return 0;
}

67 68 69 70 71 72 73 74
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;
}

75
/* Initialize CryptoAPI */
76
GIT_INLINE(int) hash_cryptoapi_prov_init()
77
{
78
	if (!CryptAcquireContext(&hash_prov.prov.cryptoapi.handle, NULL, 0, PROV_RSA_FULL, CRYPT_VERIFYCONTEXT))
79 80
		return -1;

81
	hash_prov.type = CRYPTOAPI;
82 83 84
	return 0;
}

85 86 87 88 89 90 91
GIT_INLINE(void) hash_cryptoapi_prov_shutdown(void)
{
	CryptReleaseContext(hash_prov.prov.cryptoapi.handle, 0);

	hash_prov.type = INVALID;
}

92 93 94 95 96 97 98 99 100
static void git_hash_global_shutdown(void)
{
	if (hash_prov.type == CNG)
		hash_cng_prov_shutdown();
	else if(hash_prov.type == CRYPTOAPI)
		hash_cryptoapi_prov_shutdown();
}

int git_hash_global_init(void)
101 102 103
{
	int error = 0;

104 105
	if (hash_prov.type != INVALID)
		return 0;
106

107 108
	if ((error = hash_cng_prov_init()) < 0)
		error = hash_cryptoapi_prov_init();
109

110
	git__on_shutdown(git_hash_global_shutdown);
111

112
	return error;
113 114
}

115 116
/* CryptoAPI: available in Windows XP and newer */

117
GIT_INLINE(int) hash_ctx_cryptoapi_init(git_hash_ctx *ctx)
118 119
{
	ctx->type = CRYPTOAPI;
120
	ctx->prov = &hash_prov;
121

122
	return git_hash_init(ctx);
123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138
}

GIT_INLINE(int) hash_cryptoapi_init(git_hash_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;
		return -1;
	}

	ctx->ctx.cryptoapi.valid = 1;
	return 0;
}

139
GIT_INLINE(int) hash_cryptoapi_update(git_hash_ctx *ctx, const void *_data, size_t len)
140
{
141 142
	const BYTE *data = (BYTE *)_data;

143 144
	assert(ctx->ctx.cryptoapi.valid);

145 146 147 148 149 150 151 152 153
	while (len > 0) {
		DWORD chunk = (len > MAXDWORD) ? MAXDWORD : (DWORD)len;

		if (!CryptHashData(ctx->ctx.cryptoapi.hash_handle, data, chunk, 0))
			return -1;

		data += chunk;
		len -= chunk;
	}
154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173

	return 0;
}

GIT_INLINE(int) hash_cryptoapi_final(git_oid *out, git_hash_ctx *ctx)
{
	DWORD len = 20;
	int error = 0;

	assert(ctx->ctx.cryptoapi.valid);

	if (!CryptGetHashParam(ctx->ctx.cryptoapi.hash_handle, HP_HASHVAL, out->id, &len, 0))
		error = -1;

	CryptDestroyHash(ctx->ctx.cryptoapi.hash_handle);
	ctx->ctx.cryptoapi.valid = 0;

	return error;
}

174
GIT_INLINE(void) hash_ctx_cryptoapi_cleanup(git_hash_ctx *ctx)
175 176 177 178 179 180 181
{
	if (ctx->ctx.cryptoapi.valid)
		CryptDestroyHash(ctx->ctx.cryptoapi.hash_handle);
}

/* CNG: Available in Windows Server 2008 and newer */

182
GIT_INLINE(int) hash_ctx_cng_init(git_hash_ctx *ctx)
183
{
184
	if ((ctx->ctx.cng.hash_object = git__malloc(hash_prov.prov.cng.hash_object_size)) == NULL)
185
		return -1;
186

187
	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) {
188
		git__free(ctx->ctx.cng.hash_object);
189
		return -1;
190 191 192
	}

	ctx->type = CNG;
193
	ctx->prov = &hash_prov;
194

195
	return 0;
196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213
}

GIT_INLINE(int) hash_cng_init(git_hash_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)
		return -1;

	ctx->ctx.cng.updated = 0;

	return 0;
}

214
GIT_INLINE(int) hash_cng_update(git_hash_ctx *ctx, const void *_data, size_t len)
215
{
216 217 218 219 220 221 222 223 224 225 226
	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)
			return -1;

		data += chunk;
		len -= chunk;
	}
227 228 229 230 231 232 233 234 235 236 237 238 239 240

	return 0;
}

GIT_INLINE(int) hash_cng_final(git_oid *out, git_hash_ctx *ctx)
{
	if (ctx->prov->prov.cng.finish_hash(ctx->ctx.cng.hash_handle, out->id, GIT_OID_RAWSZ, 0) < 0)
		return -1;

	ctx->ctx.cng.updated = 0;

	return 0;
}

241
GIT_INLINE(void) hash_ctx_cng_cleanup(git_hash_ctx *ctx)
242 243 244 245 246 247 248
{
	ctx->prov->prov.cng.destroy_hash(ctx->ctx.cng.hash_handle);
	git__free(ctx->ctx.cng.hash_object);
}

/* Indirection between CryptoAPI and CNG */

249
int git_hash_ctx_init(git_hash_ctx *ctx)
250
{
251
	int error = 0;
252

253
	assert(ctx);
254

255 256
	/*
	 * When compiled with GIT_THREADS, the global hash_prov data is
257
	 * initialized with git_libgit2_init.  Otherwise, it must be initialized
258 259 260 261
	 * at first use.
	 */
	if (hash_prov.type == INVALID && (error = git_hash_global_init()) < 0)
		return error;
262

263
	memset(ctx, 0x0, sizeof(git_hash_ctx));
264

265
	return (hash_prov.type == CNG) ? hash_ctx_cng_init(ctx) : hash_ctx_cryptoapi_init(ctx);
266 267
}

268
int git_hash_init(git_hash_ctx *ctx)
269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285
{
	assert(ctx && ctx->type);
	return (ctx->type == CNG) ? hash_cng_init(ctx) : hash_cryptoapi_init(ctx);
}

int git_hash_update(git_hash_ctx *ctx, const void *data, size_t len)
{
	assert(ctx && ctx->type);
	return (ctx->type == CNG) ? hash_cng_update(ctx, data, len) : hash_cryptoapi_update(ctx, data, len);
}

int git_hash_final(git_oid *out, git_hash_ctx *ctx)
{
	assert(ctx && ctx->type);
	return (ctx->type == CNG) ? hash_cng_final(out, ctx) : hash_cryptoapi_final(out, ctx);
}

286
void git_hash_ctx_cleanup(git_hash_ctx *ctx)
287
{
288
	assert(ctx);
289 290

	if (ctx->type == CNG)
291 292 293
		hash_ctx_cng_cleanup(ctx);
	else if(ctx->type == CRYPTOAPI)
		hash_ctx_cryptoapi_cleanup(ctx);
294
}