// Copyright 2017 PDFium Authors. All rights reserved. // Use of this source code is governed by a BSD-style license that can be // found in the LICENSE file. #include "public/fpdf_attachment.h" #include <memory> #include <utility> #include "constants/stream_dict_common.h" #include "core/fdrm/crypto/fx_crypt.h" #include "core/fpdfapi/parser/cpdf_array.h" #include "core/fpdfapi/parser/cpdf_document.h" #include "core/fpdfapi/parser/cpdf_name.h" #include "core/fpdfapi/parser/cpdf_number.h" #include "core/fpdfapi/parser/cpdf_reference.h" #include "core/fpdfapi/parser/cpdf_string.h" #include "core/fpdfapi/parser/fpdf_parser_decode.h" #include "core/fpdfdoc/cpdf_filespec.h" #include "core/fpdfdoc/cpdf_nametree.h" #include "core/fxcrt/cfx_datetime.h" #include "core/fxcrt/fx_extension.h" #include "fpdfsdk/cpdfsdk_helpers.h" namespace { constexpr char kChecksumKey[] = "CheckSum"; ByteString CFXByteStringHexDecode(const ByteString& bsHex) { std::unique_ptr<uint8_t, FxFreeDeleter> result; uint32_t size = 0; HexDecode(bsHex.AsRawSpan(), &result, &size); return ByteString(result.get(), size); } ByteString GenerateMD5Base16(const void* contents, const unsigned long len) { uint8_t digest[16]; CRYPT_MD5Generate(reinterpret_cast<const uint8_t*>(contents), len, digest); char buf[32]; for (int i = 0; i < 16; ++i) FXSYS_IntToTwoHexChars(digest[i], &buf[i * 2]); return ByteString(buf, 32); } } // namespace FPDF_EXPORT int FPDF_CALLCONV FPDFDoc_GetAttachmentCount(FPDF_DOCUMENT document) { CPDF_Document* pDoc = CPDFDocumentFromFPDFDocument(document); if (!pDoc) return 0; return CPDF_NameTree(pDoc, "EmbeddedFiles").GetCount(); } FPDF_EXPORT FPDF_ATTACHMENT FPDF_CALLCONV FPDFDoc_AddAttachment(FPDF_DOCUMENT document, FPDF_WIDESTRING name) { CPDF_Document* pDoc = CPDFDocumentFromFPDFDocument(document); WideString wsName = WideString::FromUTF16LE(name, WideString::WStringLength(name)); if (!pDoc || wsName.IsEmpty()) return nullptr; CPDF_Dictionary* pRoot = pDoc->GetRoot(); if (!pRoot) return nullptr; // Retrieve the document's Names dictionary; create it if missing. CPDF_Dictionary* pNames = pRoot->GetDictFor("Names"); if (!pNames) { pNames = pDoc->NewIndirect<CPDF_Dictionary>(); pRoot->SetFor("Names", pNames->MakeReference(pDoc)); } // Create the EmbeddedFiles dictionary if missing. if (!pNames->GetDictFor("EmbeddedFiles")) { CPDF_Dictionary* pFiles = pDoc->NewIndirect<CPDF_Dictionary>(); pFiles->SetNewFor<CPDF_Array>("Names"); pNames->SetFor("EmbeddedFiles", pFiles->MakeReference(pDoc)); } // Set up the basic entries in the filespec dictionary. CPDF_Dictionary* pFile = pDoc->NewIndirect<CPDF_Dictionary>(); pFile->SetNewFor<CPDF_Name>("Type", "Filespec"); pFile->SetNewFor<CPDF_String>("UF", wsName); pFile->SetNewFor<CPDF_String>(pdfium::stream::kF, wsName); // Add the new attachment name and filespec into the document's EmbeddedFiles. CPDF_NameTree nameTree(pDoc, "EmbeddedFiles"); if (!nameTree.AddValueAndName(pFile->MakeReference(pDoc), wsName)) { return nullptr; } return FPDFAttachmentFromCPDFObject(pFile); } FPDF_EXPORT FPDF_ATTACHMENT FPDF_CALLCONV FPDFDoc_GetAttachment(FPDF_DOCUMENT document, int index) { CPDF_Document* pDoc = CPDFDocumentFromFPDFDocument(document); if (!pDoc || index < 0) return nullptr; CPDF_NameTree nameTree(pDoc, "EmbeddedFiles"); if (static_cast<size_t>(index) >= nameTree.GetCount()) return nullptr; WideString csName; return FPDFAttachmentFromCPDFObject( nameTree.LookupValueAndName(index, &csName)); } FPDF_EXPORT FPDF_BOOL FPDF_CALLCONV FPDFDoc_DeleteAttachment(FPDF_DOCUMENT document, int index) { CPDF_Document* pDoc = CPDFDocumentFromFPDFDocument(document); if (!pDoc || index < 0) return false; CPDF_NameTree nameTree(pDoc, "EmbeddedFiles"); if (static_cast<size_t>(index) >= nameTree.GetCount()) return false; return nameTree.DeleteValueAndName(index); } FPDF_EXPORT unsigned long FPDF_CALLCONV FPDFAttachment_GetName(FPDF_ATTACHMENT attachment, void* buffer, unsigned long buflen) { CPDF_Object* pFile = CPDFObjectFromFPDFAttachment(attachment); if (!pFile) return 0; return Utf16EncodeMaybeCopyAndReturnLength(CPDF_FileSpec(pFile).GetFileName(), buffer, buflen); } FPDF_EXPORT FPDF_BOOL FPDF_CALLCONV FPDFAttachment_HasKey(FPDF_ATTACHMENT attachment, FPDF_BYTESTRING key) { CPDF_Object* pFile = CPDFObjectFromFPDFAttachment(attachment); if (!pFile) return 0; CPDF_Dictionary* pParamsDict = CPDF_FileSpec(pFile).GetParamsDict(); return pParamsDict ? pParamsDict->KeyExist(key) : 0; } FPDF_EXPORT FPDF_OBJECT_TYPE FPDF_CALLCONV FPDFAttachment_GetValueType(FPDF_ATTACHMENT attachment, FPDF_BYTESTRING key) { if (!FPDFAttachment_HasKey(attachment, key)) return FPDF_OBJECT_UNKNOWN; CPDF_FileSpec spec(CPDFObjectFromFPDFAttachment(attachment)); CPDF_Object* pObj = spec.GetParamsDict()->GetObjectFor(key); return pObj ? pObj->GetType() : FPDF_OBJECT_UNKNOWN; } FPDF_EXPORT FPDF_BOOL FPDF_CALLCONV FPDFAttachment_SetStringValue(FPDF_ATTACHMENT attachment, FPDF_BYTESTRING key, FPDF_WIDESTRING value) { CPDF_Object* pFile = CPDFObjectFromFPDFAttachment(attachment); if (!pFile) return false; CPDF_Dictionary* pParamsDict = CPDF_FileSpec(pFile).GetParamsDict(); if (!pParamsDict) return false; ByteString bsKey = key; ByteString bsValue = CFXByteStringFromFPDFWideString(value); bool bEncodedAsHex = bsKey == kChecksumKey; if (bEncodedAsHex) bsValue = CFXByteStringHexDecode(bsValue); pParamsDict->SetNewFor<CPDF_String>(bsKey, bsValue, bEncodedAsHex); return true; } FPDF_EXPORT unsigned long FPDF_CALLCONV FPDFAttachment_GetStringValue(FPDF_ATTACHMENT attachment, FPDF_BYTESTRING key, void* buffer, unsigned long buflen) { CPDF_Object* pFile = CPDFObjectFromFPDFAttachment(attachment); if (!pFile) return 0; CPDF_Dictionary* pParamsDict = CPDF_FileSpec(pFile).GetParamsDict(); if (!pParamsDict) return 0; ByteString bsKey = key; WideString value = pParamsDict->GetUnicodeTextFor(bsKey); if (bsKey == kChecksumKey && !value.IsEmpty()) { CPDF_String* stringValue = pParamsDict->GetObjectFor(bsKey)->AsString(); if (stringValue->IsHex()) { ByteString encoded = PDF_EncodeString(stringValue->GetString(), true); value = CPDF_String(nullptr, encoded, false).GetUnicodeText(); } } return Utf16EncodeMaybeCopyAndReturnLength(value, buffer, buflen); } FPDF_EXPORT FPDF_BOOL FPDF_CALLCONV FPDFAttachment_SetFile(FPDF_ATTACHMENT attachment, FPDF_DOCUMENT document, const void* contents, const unsigned long len) { CPDF_Object* pFile = CPDFObjectFromFPDFAttachment(attachment); CPDF_Document* pDoc = CPDFDocumentFromFPDFDocument(document); if (!pFile || !pFile->IsDictionary() || !pDoc || len > INT_MAX) return false; // An empty content must have a zero length. if (!contents && len != 0) return false; // Create a dictionary for the new embedded file stream. auto pFileStreamDict = pdfium::MakeUnique<CPDF_Dictionary>(); CPDF_Dictionary* pParamsDict = pFileStreamDict->SetNewFor<CPDF_Dictionary>("Params"); // Set the size of the new file in the dictionary. pFileStreamDict->SetNewFor<CPDF_Number>(pdfium::stream::kDL, static_cast<int>(len)); pParamsDict->SetNewFor<CPDF_Number>("Size", static_cast<int>(len)); // Set the creation date of the new attachment in the dictionary. CFX_DateTime dateTime = CFX_DateTime::Now(); pParamsDict->SetNewFor<CPDF_String>( "CreationDate", ByteString::Format("D:%d%02d%02d%02d%02d%02d", dateTime.GetYear(), dateTime.GetMonth(), dateTime.GetDay(), dateTime.GetHour(), dateTime.GetMinute(), dateTime.GetSecond()), false); // Set the checksum of the new attachment in the dictionary. pParamsDict->SetNewFor<CPDF_String>( kChecksumKey, CFXByteStringHexDecode(GenerateMD5Base16(contents, len)), true); // Create the file stream and have the filespec dictionary link to it. std::unique_ptr<uint8_t, FxFreeDeleter> stream(FX_Alloc(uint8_t, len)); memcpy(stream.get(), contents, len); CPDF_Stream* pFileStream = pDoc->NewIndirect<CPDF_Stream>( std::move(stream), len, std::move(pFileStreamDict)); CPDF_Dictionary* pEFDict = pFile->AsDictionary()->SetNewFor<CPDF_Dictionary>("EF"); pEFDict->SetFor("F", pFileStream->MakeReference(pDoc)); return true; } FPDF_EXPORT unsigned long FPDF_CALLCONV FPDFAttachment_GetFile(FPDF_ATTACHMENT attachment, void* buffer, unsigned long buflen) { CPDF_Object* pFile = CPDFObjectFromFPDFAttachment(attachment); if (!pFile) return 0; CPDF_Stream* pFileStream = CPDF_FileSpec(pFile).GetFileStream(); if (!pFileStream) return 0; return DecodeStreamMaybeCopyAndReturnLength(pFileStream, buffer, buflen); }