1 files changed, 128 insertions, 0 deletions
diff --git a/toolkit/mozapps/update/common/pathhash.cpp b/toolkit/mozapps/update/common/pathhash.cpp
new file mode 100644
index 0000000000..e70f69a755
--- /dev/null
+++ b/toolkit/mozapps/update/common/pathhash.cpp
@@ -0,0 +1,128 @@
+/* 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 ((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;
+}