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/* 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
#include <windows.h>
#include <wincrypt.h>
#include "pathhash.h"
/**
* Converts a binary sequence into a hex string
*
* @param hash The binary data sequence
* @param hashSize The size of the binary data sequence
* @param hexString A buffer to store the hex string, must be of
* size 2 * @hashSize
*/
static void BinaryDataToHexString(const BYTE* hash, DWORD& hashSize,
LPWSTR hexString) {
WCHAR* p = hexString;
for (DWORD i = 0; i < hashSize; ++i) {
wsprintfW(p, L"%.2x", hash[i]);
p += 2;
}
}
/**
* Calculates an MD5 hash for the given input binary data
*
* @param data Any sequence of bytes
* @param dataSize The number of bytes inside @data
* @param hash Output buffer to store hash, must be freed by the caller
* @param hashSize The number of bytes in the output buffer
* @return TRUE on success
*/
static BOOL CalculateMD5(const char* data, DWORD dataSize, BYTE** hash,
DWORD& hashSize) {
HCRYPTPROV hProv = 0;
HCRYPTHASH hHash = 0;
if (!CryptAcquireContext(&hProv, nullptr, nullptr, PROV_RSA_FULL,
CRYPT_VERIFYCONTEXT)) {
if ((DWORD)NTE_BAD_KEYSET != GetLastError()) {
return FALSE;
}
// Maybe it doesn't exist, try to create it.
if (!CryptAcquireContext(&hProv, nullptr, nullptr, PROV_RSA_FULL,
CRYPT_VERIFYCONTEXT | CRYPT_NEWKEYSET)) {
return FALSE;
}
}
if (!CryptCreateHash(hProv, CALG_MD5, 0, 0, &hHash)) {
return FALSE;
}
if (!CryptHashData(hHash, reinterpret_cast<const BYTE*>(data), dataSize, 0)) {
return FALSE;
}
DWORD dwCount = sizeof(DWORD);
if (!CryptGetHashParam(hHash, HP_HASHSIZE, (BYTE*)&hashSize, &dwCount, 0)) {
return FALSE;
}
*hash = new BYTE[hashSize];
ZeroMemory(*hash, hashSize);
if (!CryptGetHashParam(hHash, HP_HASHVAL, *hash, &hashSize, 0)) {
return FALSE;
}
if (hHash) {
CryptDestroyHash(hHash);
}
if (hProv) {
CryptReleaseContext(hProv, 0);
}
return TRUE;
}
/**
* Converts a file path into a unique registry location for cert storage
*
* @param filePath The input file path to get a registry path from
* @param registryPath A buffer to write the registry path to, must
* be of size in WCHARs MAX_PATH + 1
* @return TRUE if successful
*/
BOOL CalculateRegistryPathFromFilePath(const LPCWSTR filePath,
LPWSTR registryPath) {
size_t filePathLen = wcslen(filePath);
if (!filePathLen) {
return FALSE;
}
// If the file path ends in a slash, ignore that character
if (filePath[filePathLen - 1] == L'\\' || filePath[filePathLen - 1] == L'/') {
filePathLen--;
}
// Copy in the full path into our own buffer.
// Copying in the extra slash is OK because we calculate the hash
// based on the filePathLen which excludes the slash.
// +2 to account for the possibly trailing slash and the null terminator.
WCHAR* lowercasePath = new WCHAR[filePathLen + 2];
memset(lowercasePath, 0, (filePathLen + 2) * sizeof(WCHAR));
wcsncpy(lowercasePath, filePath, filePathLen + 1);
_wcslwr(lowercasePath);
BYTE* hash;
DWORD hashSize = 0;
if (!CalculateMD5(reinterpret_cast<const char*>(lowercasePath),
filePathLen * 2, &hash, hashSize)) {
delete[] lowercasePath;
return FALSE;
}
delete[] lowercasePath;
LPCWSTR baseRegPath =
L"SOFTWARE\\Mozilla\\"
L"MaintenanceService\\";
wcsncpy(registryPath, baseRegPath, MAX_PATH);
BinaryDataToHexString(hash, hashSize, registryPath + wcslen(baseRegPath));
delete[] hash;
return TRUE;
}