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fpspreadsheet: Prepare ODS reader for supporting decryption.

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git-svn-id: https://svn.code.sf.net/p/lazarus-ccr/svn@8901 8e941d3f-bd1b-0410-a28a-d453659cc2b4
This commit is contained in:
wp_xxyyzz
2023-07-27 11:00:29 +00:00
parent 4d050fb094
commit 1c9d111a60
2 changed files with 100 additions and 25 deletions
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111
components/fpspreadsheet/source/common/fpsopendocument.pas
View File

@ -76,6 +76,28 @@ type
function BuildXMLAsString(AFormatName: String): String;
end;
{ Information contained in META-INF, in particular decryption parameters. }
TsOpenDocManifestFileEntry = class
// General
FileName: String;
Encrypted: Boolean;
// Checksum of encrypted data
EncryptionData_Checksum: String;
EncryptionData_ChecksumType: String;
// Encrypting the data with the pwd hash ("key")
AlgorithmName: String;
InitializationVector: String;
IterationCount: Integer;
// Start key generation
StartKeyGenerationName: String;
StartKeySize: Integer;
// Key derivation (encrypting and salting the start key)
KeyDerivationName: String;
KeySize: Integer;
Salt: String;
end;
{ TsSpreadOpenDocReader }
TsSpreadOpenDocReader = class(TsSpreadXMLReader)
@ -179,6 +201,11 @@ type
procedure ReadNumber(ARow, ACol: Cardinal; AStyleIndex: Integer;
ACellNode: TDOMNode); reintroduce;
function Decrypt(AStream: TStream; ADecryptionInfo: TsOpenDocManifestFileEntry;
APassword: RawByteString; ADestStream: TStream): Boolean; virtual;
function SupportsDecryption: Boolean; virtual;
function UnzipToStream(AStream: TStream; AZippedFile: String;
APassword: RawByteString; ADestStream: TStream): Boolean;
public
constructor Create(AWorkbook: TsBasicWorkbook); override;
destructor Destroy; override;
@ -575,22 +602,6 @@ type
end;
*)
type
TManifestFileEntry = class
FileName: String;
Encrypted: Boolean;
EncryptionData_Checksum: String;
EncryptionData_ChecksumType: String;
AlgorithmName: String;
InitializationVector: String;
StartKeyGenerationName: String;
StartKeySize: Integer;
IterationCount: Integer;
KeyDerivationName: String;
KeySize: Integer;
Salt: String;
end;
{******************************************************************************}
{ Clipboard utility }
{******************************************************************************}
@ -2078,7 +2089,7 @@ procedure TsSpreadOpenDocReader.ReadMetaInfManifest(ANode: TDOMNode;
var
encryptionDataNode, childNode: TDOMNode;
nodeName: String;
entry: TManifestFileEntry;
entry: TsOpenDocManifestFileEntry;
begin
IsEncrypted := false;
while ANode <> nil do
@ -2086,7 +2097,7 @@ begin
nodeName := ANode.NodeName;
if nodeName = 'manifest:file-entry' then
begin
entry := TManifestFileEntry.Create;
entry := TsOpenDocManifestFileEntry.Create;
entry.FileName := GetAttrValue(ANode, 'manifest:full-path');
encryptionDataNode := ANode.FirstChild;
while encryptionDataNode <> nil do
@ -2898,20 +2909,20 @@ var
end;
begin
Unused(APassword, AParams);
Unused(AParams);
Doc := nil;
try
// Read the META-INF/manifest.xml file to learn about encryption
XMLStream := CreateXMLStream;
try
if UnzipToStream(AStream, 'META-INF/manifest.xml', XMLStream) then
if fpsXMLCommon.UnzipToStream(AStream, 'META-INF/manifest.xml', XMLStream) then
begin
ReadXMLStream(Doc, XMLStream);
if Assigned(Doc) then
begin
ReadMetaInfManifest(Doc.DocumentElement.FindNode('manifest:file-entry'), isEncrypted);
if isEncrypted then
if isEncrypted and not SupportsDecryption then
raise EFpSpreadsheetReader.Create('File is encrypted.');
end;
end;
@ -2926,7 +2937,7 @@ begin
// process the styles.xml file
XMLStream := CreateXMLStream;
try
if UnzipToStream(AStream, 'styles.xml', XMLStream) then
if UnzipToStream(AStream, 'styles.xml', APassword, XMLStream) then
ReadXMLStream(Doc, XMLStream);
finally
XMLStream.Free;
@ -2946,7 +2957,7 @@ begin
// process the content.xml file
XMLStream := CreateXMLStream;
try
if UnzipToStream(AStream, 'content.xml', XMLStream) then
if UnzipToStream(AStream, 'content.xml', APassword, XMLStream) then
ReadXMLStream(Doc, XMLStream)
else
raise EFPSpreadsheetReader.CreateFmt(rsDefectiveInternalFileStructure, ['ods']);
@ -3037,7 +3048,7 @@ begin
// process the meta.xml file
XMLStream := CreateXMLStream;
try
if UnzipToStream(AStream, 'meta.xml', XMLStream) then
if UnzipToStream(AStream, 'meta.xml', APassword, XMLStream) then
begin
ReadXMLStream(Doc, XMLStream);
try
@ -3053,7 +3064,7 @@ begin
// process the settings.xml file (Note: it does not always exist!)
XMLStream := CreateXMLStream;
try
if UnzipToStream(AStream, 'settings.xml', XMLStream) then
if UnzipToStream(AStream, 'settings.xml', APassword, XMLStream) then
begin
ReadXMLStream(Doc, XMLStream);
try
@ -5584,6 +5595,56 @@ begin
FTableStyleList.Add(tablestyle);
end;
{ The standard ods reader does not support decryption. Must be overridden in a
descendant reader class which implements decryption taking advantage of the
provided password and the parameters in ADecryptionInfo. }
function TsSpreadOpenDocReader.Decrypt(AStream: TStream;
ADecryptionInfo: TsOpenDocManifestFileEntry; APassword: RawByteString;
ADestStream: TStream): Boolean;
begin
Result := false;
end;
{ If a descendant reader class supports decryption it must return true
here. The standard ods reader is not able to read encrypted file content. }
function TsSpreadOpenDocReader.SupportsDecryption: Boolean;
begin
Result := false;
end;
function TsSpreadOpenDocReader.UnzipToStream(AStream: TStream; AZippedFile: String;
APassword: RawByteString; ADestStream: TStream): Boolean;
var
i: Integer;
mfe: TsOpenDocManifestFileEntry;
isEncrypted: Boolean;
tmpStream: TStream;
begin
mfe := nil;
// Find the requested file among the manifest file entries containing
// parameters needed for decryption.
for i := 0 to FManifestFileEntries.Count-1 do
if TsOpenDocManifestFileEntry(FManifestFileEntries[i]).FileName = AZippedFile then
begin
mfe := TsOpenDocManifestFileEntry(FManifestFileEntries[i]);
isEncrypted := mfe.Encrypted;
break;
end;
if isEncrypted then begin
tmpStream := TMemoryStream.Create;
try
// Read the encrypted file from the input stream
Result := fpsXMLCommon.UnzipToStream(AStream, AZippedFile, tmpStream);
// Decrypt the file into the destination stream
Result := Result and Decrypt(tmpStream, mfe, APassword, ADestStream);
finally
tmpStream.Free;
end;
end else
Result := fpsXMLCommon.UnzipToStream(AStream, AZippedFile, ADestStream);
end;
{ TsSpreadOpenDocWriter }

14
components/fpspreadsheet/source/common/fpsreaderwriter.pas
View File

@ -204,6 +204,8 @@ function RegisterSpreadFormat(
AFormatName, ATechnicalName: String;
const AFileExtensions: array of String): TsSpreadFormatID;
procedure UnregisterSpreadFormat(AFormatID: TsSpreadFormatID);
function GetFileFormatFilter(AListSeparator, AExtSeparator: Char;
AFileAccess: TsSpreadFileAccess; const APriorityFormats: array of TsSpreadFormatID;
AllSpreadFormats: Boolean = false; AllExcelFormats: Boolean = false): String;
@ -1326,6 +1328,18 @@ begin
Result := fmt.FormatID;
end;
procedure UnregisterSpreadFormat(AFormatID: TsSpreadFormatID);
var
n: Integer;
begin
n := SpreadFormatRegistry.IndexOf(AFormatID);
if n <> -1 then
begin
TObject(SpreadFormatRegistry.FList[n]).Free;
SpreadFormatRegistry.FList.Delete(n);
end;
end;
function GetFileFormatFilter(AListSeparator, AExtSeparator: Char;
AFileAccess: TsSpreadFileAccess; const APriorityFormats: array of TsSpreadFormatID;
AllSpreadFormats: Boolean = false; AllExcelFormats: Boolean = false): String;