Delphi 编写数字签名验证并获取签名信息

[摘要]本文介绍Delphi 编写数字签名验证并获取签名信息，并提供详细的示例代码供参考。

一个客户想通过编程实现验证程序自身的数字签名来确保程序的完整性，防范病毒感染以及防止一些无聊人士的修改(通过十六进制编辑器替换一些版权、网址、LOGO..)； 为此我做了一个数字签名验证的小例子，其中也有获取签名者信息的方法，以满足“自验证”的需求。

示例图：

Windows API：

安全编录(CAT)

• CryptCATAdminReleaseCatalogContext
• CryptCATCatalogInfoFromContext
• CryptCATAdminEnumCatalogFromHash
• CryptCATAdminCalcHashFromFileHandle
• CryptCATAdminReleaseContext
• CryptCATAdminAcquireContext

验证文件的签名(主API)

• WinVerifyTrust

获取签名信息

• WTHelperProvDataFromStateData

获取证书名字信息

• CertGetNameString

Delphi 编写数字签名验证并获取签名信息代码如下：

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{   * by: HouSoft   * site: www.yryz.net   * created: 2012/02/03 } unit Unit1;    interface    uses   Windows, Sysutils, jwaWinCrypt, WinTrustApi;    procedure Test;    implementation    procedure PrintCertChain(pCertChain: PCERT_SIMPLE_CHAIN); var   I: Integer;   sBuf: string; begin   // 开启指针运算 {$POINTERMATH ON}   //   // 输出书链元素   for I := pCertChain^.cElement - 1 downto 0 do   begin     SetLength(sBuf, 1024);     SetLength(sBuf,       CertGetNameString(       pCertChain^.rgpElement[I].pCertContext,       CERT_NAME_SIMPLE_DISPLAY_TYPE, // 简单名字       0,       nil,       PChar(sBuf),       Length(sBuf)) - 1);        WriteLn(#9, StringOfChar(' ', 2 * (pCertChain^.cElement - I - 1)), sBuf);   end; end;    procedure OutSignerInfo(hWVTStateData: THANDLE); var   provData: PCRYPT_PROVIDER_DATA;   LSysTime: TSystemTime; begin   // 获取签名信息   // http://msdn.microsoft.com/ZH-CN/library/windows/desktop/aa388429(v=vs.85).aspx      provData := WTHelperProvDataFromStateData(hWVTStateData);   if (provData <> nil) and (provData^.pasSigners <> nil) then   begin     // 采用安全编录(CAT)签名     if provData^.pPDSip^.psSipCATSubjectInfo <> nil then     begin       WriteLn('安全编录: ');       WriteLn(#9, provData^.pPDSip^.psSipCATSubjectInfo^.pwsFileName);       WriteLn('');     end;        /// 注意： provData^.pasSigners 是数组， 但常见的都是一个元素，so...        // 时间戳     if provData^.pasSigners^.pasCounterSigners <> nil then     begin       FileTimeToSystemTime(provData^.pasSigners^.pasCounterSigners^.sftVerifyAsOf, LSysTime);       WriteLn('时间戳: ');       WriteLn(#9, FormatDateTime('yyyy-MM-dd hh:mm:ss', SystemTimeToDateTime(LSysTime)));       WriteLn('');       WriteLn('时间戳证书链: ');       PrintCertChain(provData^.pasSigners^.pasCounterSigners^.pChainContext^.rgpChain[0]);       WriteLn('');     end;        WriteLn('签名者证书链：');     PrintCertChain(provData^.pasSigners^.pChainContext^.rgpChain[0]);     WriteLn('');   end; end;    function SignVerify(FileName: string): Boolean; var   aByteHash: array [0 .. 255] of Byte;   iByteCount: Integer;      hCatAdminContext: HCatAdmin;   WTrustData: WINTRUST_DATA;   WTDCatalogInfo: WINTRUST_CATALOG_INFO;   WTDFileInfo: WINTRUST_FILE_INFO;   CatalogInfo: CATALOG_INFO;      hFile: THANDLE;   hCatalogContext: THANDLE;      swFilename: WideString;   swMemberTag: WideString;      ilRet: Longint;   I: Integer; begin   Result := False;      if not FileExists(FileName) then     Exit;      swFilename := FileName;      ZeroMemory(@CatalogInfo, SizeOf(CatalogInfo));   ZeroMemory(@WTDFileInfo, SizeOf(WTDFileInfo));   ZeroMemory(@WTDCatalogInfo, SizeOf(WTDCatalogInfo));   ZeroMemory(@WTrustData, SizeOf(WTrustData));      hCatalogContext := 0;   hCatAdminContext := 0;      try     // 先查询安全编目     if not CryptCATAdminAcquireContext(@hCatAdminContext,       nil,       0) then       Exit;        hFile := CreateFile(PChar(FileName),       GENERIC_READ,       FILE_SHARE_READ,       nil,       OPEN_EXISTING,       FILE_ATTRIBUTE_NORMAL,       0);        if hFile = INVALID_HANDLE_VALUE then       Exit;        iByteCount := SizeOf(aByteHash);        // 文件哈希函数计算的     CryptCATAdminCalcHashFromFileHandle(hFile,       @iByteCount,       @aByteHash,       0);        for i := 0 to iByteCount - 1 do     begin       swMemberTag := swMemberTag + IntToHex(aByteHash[i], 2);     end;        CloseHandle(hFile);        // 枚举目录包含一个指定的哈希     hCatalogContext := CryptCATAdminEnumCatalogFromHash(hCatAdminContext,       @aByteHash,       iByteCount,       0,       nil);        // 准备验证参数     // http://msdn.microsoft.com/en-us/library/windows/desktop/aa388205(v=vs.85).aspx        WTrustData.dwUIChoice := WTD_UI_NONE;     WTrustData.fdwRevocationChecks := WTD_REVOKE_NONE;     WTrustData.dwStateAction := WTD_STATEACTION_VERIFY; // 获取信息后需要手动 WTD_STATEACTION_CLOSE     WTrustData.dwProvFlags := WTD_REVOCATION_CHECK_NONE;        if hCatalogContext = 0 then // 未找到包含此文件的安全编目     begin       WTDFileInfo.cbStruct := SizeOf(WTDFileInfo);       WTDFileInfo.pcwszFilePath := PWideChar(swFilename);          WTrustData.cbStruct := SizeOf(WTrustData);       WTrustData.dwUnionChoice := WTD_CHOICE_FILE;       WTrustData.union.pFile := @WTDFileInfo;        end     else     begin       CryptCATCatalogInfoFromContext(hCatalogContext, @CatalogInfo, 0);          WTDCatalogInfo.cbStruct := SizeOf(WTDCatalogInfo);       WTDCatalogInfo.pcwszCatalogFilePath := CatalogInfo.sCatalogFile;       WTDCatalogInfo.pcwszMemberFilePath := PWideChar(swFilename);       WTDCatalogInfo.pcwszMemberTag := PWideChar(swMemberTag);          WTrustData.cbStruct := SizeOf(WTrustData);       WTrustData.dwUnionChoice := WTD_CHOICE_CATALOG;       WTrustData.union.pCatalog := @WTDCatalogInfo;          // WriteLn(CatalogInfo.sCatalogFile);     end;        // 验证     // http://msdn.microsoft.com/en-us/library/windows/desktop/aa388208(v=vs.85).aspx     ilRet := WinVerifyTrust(INVALID_HANDLE_VALUE,       @WINTRUST_ACTION_GENERIC_VERIFY_V2,       @WTrustData);        Result := ilRet = 0;        // 输出签名信息     OutSignerInfo(WTrustData.hWVTStateData);        // 释放     WTrustData.dwStateAction := WTD_STATEACTION_CLOSE;     WinVerifyTrust(INVALID_HANDLE_VALUE,       @WINTRUST_ACTION_GENERIC_VERIFY_V2,       @WTrustData);   finally     if hCatAdminContext > 0 then     begin       if hCatalogContext > 0 then         CryptCATAdminReleaseCatalogContext(hCatAdminContext,           hCatalogContext, 0);          CryptCATAdminReleaseContext(hCatAdminContext, 0);     end;   end; end;    procedure Test; begin   if ParamCount < 1 then   begin     WriteLn('请输入要验证的文件名!');     Exit;   end;      if SignVerify(ParamStr(1)) then     WriteLn('签名有效.')   else     WriteLn('签名无效.'); end;    end.