1 files changed, 146 insertions, 0 deletions
diff --git a/toolkit/components/downloads/SQLFunctions.cpp b/toolkit/components/downloads/SQLFunctions.cpp
new file mode 100644
index 000000000..8f2d3e77b
--- /dev/null
+++ b/toolkit/components/downloads/SQLFunctions.cpp
@@ -0,0 +1,146 @@
+/* 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)
+{
+  RefPtr<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 downloads
+} // namespace mozilla