gecko-dev/toolkit/components/downloads/SQLFunctions.cpp

147 строки
4.2 KiB
C++

/* vim: sw=2 ts=2 et lcs=trail\:.,tab\:>~ :
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#include "mozilla/storage.h"
#include "mozilla/storage/Variant.h"
#include "mozilla/mozalloc.h"
#include "nsString.h"
#include "SQLFunctions.h"
#include "nsUTF8Utils.h"
#include "plbase64.h"
#include "prio.h"
#ifdef XP_WIN
#include <windows.h>
#include <wincrypt.h>
#endif
// The length of guids that are used by the download manager
#define GUID_LENGTH 12
namespace mozilla {
namespace downloads {
// Keep this file in sync with the GUID-related code in toolkit/places/SQLFunctions.cpp
// and toolkit/places/Helpers.cpp!
////////////////////////////////////////////////////////////////////////////////
//// GUID Creation Function
//////////////////////////////////////////////////////////////////////////////
//// GenerateGUIDFunction
/* static */
nsresult
GenerateGUIDFunction::create(mozIStorageConnection *aDBConn)
{
nsRefPtr<GenerateGUIDFunction> function = new GenerateGUIDFunction();
nsresult rv = aDBConn->CreateFunction(
NS_LITERAL_CSTRING("generate_guid"), 0, function
);
NS_ENSURE_SUCCESS(rv, rv);
return NS_OK;
}
NS_IMPL_ISUPPORTS(
GenerateGUIDFunction,
mozIStorageFunction
)
static
nsresult
Base64urlEncode(const uint8_t* aBytes,
uint32_t aNumBytes,
nsCString& _result)
{
// SetLength does not set aside space for null termination. PL_Base64Encode
// will not null terminate, however, nsCStrings must be null terminated. As a
// result, we set the capacity to be one greater than what we need, and the
// length to our desired length.
uint32_t length = (aNumBytes + 2) / 3 * 4; // +2 due to integer math.
NS_ENSURE_TRUE(_result.SetCapacity(length + 1, mozilla::fallible),
NS_ERROR_OUT_OF_MEMORY);
_result.SetLength(length);
(void)PL_Base64Encode(reinterpret_cast<const char*>(aBytes), aNumBytes,
_result.BeginWriting());
// base64url encoding is defined in RFC 4648. It replaces the last two
// alphabet characters of base64 encoding with '-' and '_' respectively.
_result.ReplaceChar('+', '-');
_result.ReplaceChar('/', '_');
return NS_OK;
}
static
nsresult
GenerateRandomBytes(uint32_t aSize,
uint8_t* _buffer)
{
// On Windows, we'll use its built-in cryptographic API.
#if defined(XP_WIN)
HCRYPTPROV cryptoProvider;
BOOL rc = CryptAcquireContext(&cryptoProvider, 0, 0, PROV_RSA_FULL,
CRYPT_VERIFYCONTEXT | CRYPT_SILENT);
if (rc) {
rc = CryptGenRandom(cryptoProvider, aSize, _buffer);
(void)CryptReleaseContext(cryptoProvider, 0);
}
return rc ? NS_OK : NS_ERROR_FAILURE;
// On Unix, we'll just read in from /dev/urandom.
#elif defined(XP_UNIX)
NS_ENSURE_ARG_MAX(aSize, INT32_MAX);
PRFileDesc* urandom = PR_Open("/dev/urandom", PR_RDONLY, 0);
nsresult rv = NS_ERROR_FAILURE;
if (urandom) {
int32_t bytesRead = PR_Read(urandom, _buffer, aSize);
if (bytesRead == static_cast<int32_t>(aSize)) {
rv = NS_OK;
}
(void)PR_Close(urandom);
}
return rv;
#endif
}
nsresult
GenerateGUID(nsCString& _guid)
{
_guid.Truncate();
// Request raw random bytes and base64url encode them. For each set of three
// bytes, we get one character.
const uint32_t kRequiredBytesLength =
static_cast<uint32_t>(GUID_LENGTH / 4 * 3);
uint8_t buffer[kRequiredBytesLength];
nsresult rv = GenerateRandomBytes(kRequiredBytesLength, buffer);
NS_ENSURE_SUCCESS(rv, rv);
rv = Base64urlEncode(buffer, kRequiredBytesLength, _guid);
NS_ENSURE_SUCCESS(rv, rv);
NS_ASSERTION(_guid.Length() == GUID_LENGTH, "GUID is not the right size!");
return NS_OK;
}
//////////////////////////////////////////////////////////////////////////////
//// mozIStorageFunction
NS_IMETHODIMP
GenerateGUIDFunction::OnFunctionCall(mozIStorageValueArray *aArguments,
nsIVariant **_result)
{
nsAutoCString guid;
nsresult rv = GenerateGUID(guid);
NS_ENSURE_SUCCESS(rv, rv);
NS_ADDREF(*_result = new mozilla::storage::UTF8TextVariant(guid));
return NS_OK;
}
} // namespace mozilla
} // namespace downloads