/* 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 <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 (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; }