//Description: 文件签名
//Create Date: 2021-02-01 00:09:20
//Author: channy
| 序号 | 加密 | 签名 |
|---|---|---|
| 1 | 保护发送端，保证数据不被第三方篡改 | 保护接收端，保证数据是从可信任方发送过来的 |
| 2 | 使用接收方公钥加密 | 使用发送方私钥签名 |
见pe文件结构
微软自带签名工具signtool
将签名数据另存为.cat的文件中，并不嵌入到pe文件里面。可对任意格式文件进行签名。
编录文件的签名微软并未公开格式文档。
对于嵌入式签名，
WIN_CERTIFICATE.bCertificate是SignedData格式的签名
用IssuerAndSerialNumber找到签名者的证书，使用里面的公钥解密EncryptedDigest得到一个DigestInfo结构（一般是RSA算法），将这个结构与authenticatedAttributes做摘要得到的结构对比
AuthorityKeyIdentifier和SubjectKeyIdentifier
组建证书链时，将把A证书的中的AuthorityKeyIdentifier（简称AKID） 的keyIdentifier、authorityCertIssuer、authorityCertSerialNumber与B证书的SubjectKeyIdentifier（简称SKID）、issuer 、serialNumber分别匹配，如果匹配上则B证书为A证书的签发者。如果A证书的上面三项与自己对应数据匹配上，则A证书为自签名的证书，证书链构建完毕。
校验证书链中每个证书的签名、有效期和用法（是否可以用于代码签名）。签名验证的算法为证书中的signatureAlgorithm，签名是signatureValue，被签名的数据为tbsCertificate，公钥从父证书的subjectPublicKeyInfo里面拿。
签名数据中的Hash算法和Hash在SignedData的contentInfo中
CERT_INFO里包含了证书的一些基本信息，包括版本、序列号、签名算法、期效等等
CMSG_SIGNER_INFO里包含了签名者的信息，包括版本、序列号、签名算法、加密信息的hash等
SPROG_PUBLISHERINFO则包含证书颁发机构等
公钥 CERT_INFO.SubjectPublicKeyInfo
| 序号 | api | 功能 |
|---|---|---|
| 1 | WinVerifyTrust | 验证签名证书 |
| 2 | CryptQueryObject | 获取签名信息HCRYPTMSG |
| 3 | CryptMsgGetParam | 获取签名者信息PCMSG_SIGNER_INFO |
| 4 | GetProgAndPublisherInfo | |
| 5 | CertFindCertificateInStore | 从商店中获取证书信息 |
| 6 | GetTimeStampSignerInfo | 获取时间戳 |
| 7 | GetDateOfTimeStamp | 获取证书期限 |
| 8 | CertGetNameString |
验证CRL（销证书列表）时使用的WinINet系列API性能不好。这个系列的API是出了名的不稳定，而且据说可能会导致堆破坏
枚举签名时的死循环。据说在XP系统上WinVerfiyTrust在校验PE文件嵌入式签名时，循环枚举签名时没有判断签名的长度，如果PE文件被破坏，签名长度为0的话，WinVerfiyTrust会陷入死循环。
对Windows 平台下PE文件数字签名的一些研究 openssl
#include <windows.h>
#include <tchar.h>
#include <stdio.h>
#include <psapi.h>
#include <Softpub.h>
#include <Mscat.h>
#pragma comment (lib, "wintrust")
// To ensure correct resolution of symbols, add Psapi.lib to TARGETLIBS
// and compile with -DPSAPI_VERSION=1
BOOL CheckFileTrust(LPCWSTR lpFileName)
{
BOOL bRet = FALSE;
WINTRUST_DATA wd = { 0 };
WINTRUST_FILE_INFO wfi = { 0 };
WINTRUST_CATALOG_INFO wci = { 0 };
CATALOG_INFO ci = { 0 };
HCATADMIN hCatAdmin = NULL;
if (!CryptCATAdminAcquireContext(&hCatAdmin, NULL, 0))
{
return FALSE;
}
HANDLE hFile = CreateFileW(lpFileName, GENERIC_READ, FILE_SHARE_READ,
NULL, OPEN_EXISTING, 0, NULL);
if (INVALID_HANDLE_VALUE == hFile)
{
CryptCATAdminReleaseContext(hCatAdmin, 0);
return FALSE;
}
DWORD dwCnt = 100;
BYTE byHash[100];
CryptCATAdminCalcHashFromFileHandle(hFile, &dwCnt, byHash, 0);
CloseHandle(hFile);
LPWSTR pszMemberTag = new WCHAR[dwCnt * 2 + 1];
for (DWORD dw = 0; dw < dwCnt; ++dw)
{
wsprintfW(&pszMemberTag[dw * 2], L"%02X", byHash[dw]);
}
HCATINFO hCatInfo = CryptCATAdminEnumCatalogFromHash(hCatAdmin,
byHash, dwCnt, 0, NULL);
if (NULL == hCatInfo)
{
wfi.cbStruct = sizeof(WINTRUST_FILE_INFO);
wfi.pcwszFilePath = lpFileName;
wfi.hFile = NULL;
wfi.pgKnownSubject = NULL;
wd.cbStruct = sizeof(WINTRUST_DATA);
wd.dwUnionChoice = WTD_CHOICE_FILE;
wd.pFile = &wfi;
wd.dwUIChoice = WTD_UI_NONE;
wd.fdwRevocationChecks = WTD_REVOKE_NONE;
wd.dwStateAction = WTD_STATEACTION_IGNORE;
wd.dwProvFlags = WTD_SAFER_FLAG;
wd.hWVTStateData = NULL;
wd.pwszURLReference = NULL;
}
else
{
CryptCATCatalogInfoFromContext(hCatInfo, &ci, 0);
wci.cbStruct = sizeof(WINTRUST_CATALOG_INFO);
wci.pcwszCatalogFilePath = ci.wszCatalogFile;
wci.pcwszMemberFilePath = lpFileName;
wci.pcwszMemberTag = pszMemberTag;
wd.cbStruct = sizeof(WINTRUST_DATA);
wd.dwUnionChoice = WTD_CHOICE_CATALOG;
wd.pCatalog = &wci;
wd.dwUIChoice = WTD_UI_NONE;
wd.fdwRevocationChecks = WTD_STATEACTION_VERIFY;
wd.dwProvFlags = 0;
wd.hWVTStateData = NULL;
wd.pwszURLReference = NULL;
}
GUID action = WINTRUST_ACTION_GENERIC_VERIFY_V2;
HRESULT hr = WinVerifyTrust(NULL, &action, &wd);
bRet = SUCCEEDED(hr);
if (NULL != hCatInfo)
{
CryptCATAdminReleaseCatalogContext(hCatAdmin, hCatInfo, 0);
}
CryptCATAdminReleaseContext(hCatAdmin, 0);
delete[] pszMemberTag;
return bRet;
}
int _tmain(int argc, TCHAR* argv[])
{
CheckFileTrust(L"C:/downloadInstallers/BaiduNetdisk_7.0.13.2.exe");
return 0;
}
#include <windows.h>
#include <wincrypt.h>
#include <wintrust.h>
#include <stdio.h>
#include <tchar.h>
#include <SoftPub.h>
#pragma comment(lib, "crypt32.lib")
#pragma comment (lib, "wintrust")
#define ENCODING (X509_ASN_ENCODING | PKCS_7_ASN_ENCODING)
typedef struct {
LPWSTR lpszProgramName;
LPWSTR lpszPublisherLink;
LPWSTR lpszMoreInfoLink;
} SPROG_PUBLISHERINFO, * PSPROG_PUBLISHERINFO;
BOOL GetProgAndPublisherInfo(PCMSG_SIGNER_INFO pSignerInfo,
PSPROG_PUBLISHERINFO Info);
BOOL GetDateOfTimeStamp(PCMSG_SIGNER_INFO pSignerInfo, SYSTEMTIME* st);
BOOL PrintCertificateInfo(PCCERT_CONTEXT pCertContext);
BOOL GetTimeStampSignerInfo(PCMSG_SIGNER_INFO pSignerInfo,
PCMSG_SIGNER_INFO* pCounterSignerInfo);
BOOL VerifyEmbeddedSignature(LPCWSTR pwszSourceFile)
{
LONG lStatus;
DWORD dwLastError;
// Initialize the WINTRUST_FILE_INFO structure.
WINTRUST_FILE_INFO FileData;
memset(&FileData, 0, sizeof(FileData));
FileData.cbStruct = sizeof(WINTRUST_FILE_INFO);
FileData.pcwszFilePath = pwszSourceFile;
FileData.hFile = NULL;
FileData.pgKnownSubject = NULL;
/*
WVTPolicyGUID specifies the policy to apply on the file
WINTRUST_ACTION_GENERIC_VERIFY_V2 policy checks:
1) The certificate used to sign the file chains up to a root
certificate located in the trusted root certificate store. This
implies that the identity of the publisher has been verified by
a certification authority.
2) In cases where user interface is displayed (which this example
does not do), WinVerifyTrust will check for whether the
end entity certificate is stored in the trusted publisher store,
implying that the user trusts content from this publisher.
3) The end entity certificate has sufficient permission to sign
code, as indicated by the presence of a code signing EKU or no
EKU.
*/
GUID WVTPolicyGUID = WINTRUST_ACTION_GENERIC_VERIFY_V2;
WINTRUST_DATA WinTrustData;
// Initialize the WinVerifyTrust input data structure.
// Default all fields to 0.
memset(&WinTrustData, 0, sizeof(WinTrustData));
WinTrustData.cbStruct = sizeof(WinTrustData);
// Use default code signing EKU.
WinTrustData.pPolicyCallbackData = NULL;
// No data to pass to SIP.
WinTrustData.pSIPClientData = NULL;
// Disable WVT UI.
WinTrustData.dwUIChoice = WTD_UI_NONE;
// No revocation checking.
WinTrustData.fdwRevocationChecks = WTD_REVOKE_NONE;
// Verify an embedded signature on a file.
WinTrustData.dwUnionChoice = WTD_CHOICE_FILE;
// Verify action.
WinTrustData.dwStateAction = WTD_STATEACTION_VERIFY;
// Verification sets this value.
WinTrustData.hWVTStateData = NULL;
// Not used.
WinTrustData.pwszURLReference = NULL;
// This is not applicable if there is no UI because it changes
// the UI to accommodate running applications instead of
// installing applications.
WinTrustData.dwUIContext = 0;
// Set pFile.
WinTrustData.pFile = &FileData;
// WinVerifyTrust verifies signatures as specified by the GUID
// and Wintrust_Data.
lStatus = WinVerifyTrust(
NULL,
&WVTPolicyGUID,
&WinTrustData);
switch (lStatus)
{
case ERROR_SUCCESS:
/*
Signed file:
- Hash that represents the subject is trusted.
- Trusted publisher without any verification errors.
- UI was disabled in dwUIChoice. No publisher or
time stamp chain errors.
- UI was enabled in dwUIChoice and the user clicked
"Yes" when asked to install and run the signed
subject.
*/
wprintf_s(L"The file \"%s\" is signed and the signature "
L"was verified.\n",
pwszSourceFile);
break;
case TRUST_E_NOSIGNATURE:
// The file was not signed or had a signature
// that was not valid.
// Get the reason for no signature.
dwLastError = GetLastError();
if (TRUST_E_NOSIGNATURE == dwLastError ||
TRUST_E_SUBJECT_FORM_UNKNOWN == dwLastError ||
TRUST_E_PROVIDER_UNKNOWN == dwLastError)
{
// The file was not signed.
wprintf_s(L"The file \"%s\" is not signed.\n",
pwszSourceFile);
}
else
{
// The signature was not valid or there was an error
// opening the file.
wprintf_s(L"An unknown error occurred trying to "
L"verify the signature of the \"%s\" file.\n",
pwszSourceFile);
}
break;
case TRUST_E_EXPLICIT_DISTRUST:
// The hash that represents the subject or the publisher
// is not allowed by the admin or user.
wprintf_s(L"The signature is present, but specifically "
L"disallowed.\n");
break;
case TRUST_E_SUBJECT_NOT_TRUSTED:
// The user clicked "No" when asked to install and run.
wprintf_s(L"The signature is present, but not "
L"trusted.\n");
break;
case CRYPT_E_SECURITY_SETTINGS:
/*
The hash that represents the subject or the publisher
was not explicitly trusted by the admin and the
admin policy has disabled user trust. No signature,
publisher or time stamp errors.
*/
wprintf_s(L"CRYPT_E_SECURITY_SETTINGS - The hash "
L"representing the subject or the publisher wasn't "
L"explicitly trusted by the admin and admin policy "
L"has disabled user trust. No signature, publisher "
L"or timestamp errors.\n");
break;
default:
// The UI was disabled in dwUIChoice or the admin policy
// has disabled user trust. lStatus contains the
// publisher or time stamp chain error.
wprintf_s(L"Error is: 0x%x.\n",
lStatus);
break;
}
// Any hWVTStateData must be released by a call with close.
WinTrustData.dwStateAction = WTD_STATEACTION_CLOSE;
lStatus = WinVerifyTrust(
NULL,
&WVTPolicyGUID,
&WinTrustData);
return true;
}
int _tmain(int argc, TCHAR* argv[])
{
WCHAR szFileName[MAX_PATH];
HCERTSTORE hStore = NULL;
HCRYPTMSG hMsg = NULL;
PCCERT_CONTEXT pCertContext = NULL;
BOOL fResult;
DWORD dwEncoding, dwContentType, dwFormatType;
PCMSG_SIGNER_INFO pSignerInfo = NULL;
PCMSG_SIGNER_INFO pCounterSignerInfo = NULL;
DWORD dwSignerInfo;
CERT_INFO CertInfo;
SPROG_PUBLISHERINFO ProgPubInfo;
SYSTEMTIME st;
ZeroMemory(&ProgPubInfo, sizeof(ProgPubInfo));
__try
{
if (argc != 2)
{
_tprintf(_T("Usage: SignedFileInfo <filename>\n"));
return 0;
}
# ifdef UNICODE
lstrcpynW(szFileName, argv[1], MAX_PATH);
#else
if (mbstowcs(szFileName, argv[1], MAX_PATH) == -1)
{
printf("Unable to convert to unicode.\n");
__leave;
}
#endif
// Get message handle and store handle from the signed file.
fResult = CryptQueryObject(CERT_QUERY_OBJECT_FILE,
szFileName,
CERT_QUERY_CONTENT_FLAG_PKCS7_SIGNED_EMBED,
CERT_QUERY_FORMAT_FLAG_BINARY,
0,
&dwEncoding,
&dwContentType,
&dwFormatType,
&hStore,
&hMsg,
NULL);
if (!fResult)
{
_tprintf(_T("CryptQueryObject failed with %x\n"), GetLastError());
__leave;
}
// Get signer information size.
fResult = CryptMsgGetParam(hMsg,
CMSG_SIGNER_INFO_PARAM,
0,
NULL,
&dwSignerInfo);
if (!fResult)
{
_tprintf(_T("CryptMsgGetParam failed with %x\n"), GetLastError());
__leave;
}
// Allocate memory for signer information.
pSignerInfo = (PCMSG_SIGNER_INFO)LocalAlloc(LPTR, dwSignerInfo);
if (!pSignerInfo)
{
_tprintf(_T("Unable to allocate memory for Signer Info.\n"));
__leave;
}
// Get Signer Information.
fResult = CryptMsgGetParam(hMsg,
CMSG_SIGNER_INFO_PARAM,
0,
(PVOID)pSignerInfo,
&dwSignerInfo);
if (!fResult)
{
_tprintf(_T("CryptMsgGetParam failed with %x\n"), GetLastError());
__leave;
}
// Get program name and publisher information from
// signer info structure.
if (GetProgAndPublisherInfo(pSignerInfo, &ProgPubInfo))
{
if (ProgPubInfo.lpszProgramName != NULL)
{
wprintf(L"Program Name : %s\n",
ProgPubInfo.lpszProgramName);
}
if (ProgPubInfo.lpszPublisherLink != NULL)
{
wprintf(L"Publisher Link : %s\n",
ProgPubInfo.lpszPublisherLink);
}
if (ProgPubInfo.lpszMoreInfoLink != NULL)
{
wprintf(L"MoreInfo Link : %s\n",
ProgPubInfo.lpszMoreInfoLink);
}
}
_tprintf(_T("\n"));
// Search for the signer certificate in the temporary
// certificate store.
CertInfo.Issuer = pSignerInfo->Issuer;
CertInfo.SerialNumber = pSignerInfo->SerialNumber;
pCertContext = CertFindCertificateInStore(hStore,
ENCODING,
0,
CERT_FIND_SUBJECT_CERT,
(PVOID)&CertInfo,
NULL);
if (!pCertContext)
{
_tprintf(_T("CertFindCertificateInStore failed with %x\n"),
GetLastError());
__leave;
}
// Print Signer certificate information.
_tprintf(_T("Signer Certificate:\n\n"));
PrintCertificateInfo(pCertContext);
_tprintf(_T("\n"));
// Get the timestamp certificate signerinfo structure.
if (GetTimeStampSignerInfo(pSignerInfo, &pCounterSignerInfo))
{
// Search for Timestamp certificate in the temporary
// certificate store.
CertInfo.Issuer = pCounterSignerInfo->Issuer;
CertInfo.SerialNumber = pCounterSignerInfo->SerialNumber;
pCertContext = CertFindCertificateInStore(hStore,
ENCODING,
0,
CERT_FIND_SUBJECT_CERT,
(PVOID)&CertInfo,
NULL);
if (!pCertContext)
{
_tprintf(_T("CertFindCertificateInStore failed with %x\n"),
GetLastError());
__leave;
}
// Print timestamp certificate information.
_tprintf(_T("TimeStamp Certificate:\n\n"));
PrintCertificateInfo(pCertContext);
_tprintf(_T("\n"));
// Find Date of timestamp.
if (GetDateOfTimeStamp(pCounterSignerInfo, &st))
{
_tprintf(_T("Date of TimeStamp : %02d/%02d/%04d %02d:%02d\n"),
st.wMonth,
st.wDay,
st.wYear,
st.wHour,
st.wMinute);
}
_tprintf(_T("\n"));
}
}
__finally
{
// Clean up.
if (ProgPubInfo.lpszProgramName != NULL)
LocalFree(ProgPubInfo.lpszProgramName);
if (ProgPubInfo.lpszPublisherLink != NULL)
LocalFree(ProgPubInfo.lpszPublisherLink);
if (ProgPubInfo.lpszMoreInfoLink != NULL)
LocalFree(ProgPubInfo.lpszMoreInfoLink);
if (pSignerInfo != NULL) LocalFree(pSignerInfo);
if (pCounterSignerInfo != NULL) LocalFree(pCounterSignerInfo);
if (pCertContext != NULL) CertFreeCertificateContext(pCertContext);
if (hStore != NULL) CertCloseStore(hStore, 0);
if (hMsg != NULL) CryptMsgClose(hMsg);
}
return 0;
}
BOOL PrintCertificateInfo(PCCERT_CONTEXT pCertContext)
{
BOOL fReturn = FALSE;
LPTSTR szName = NULL;
DWORD dwData;
__try
{
// Print Serial Number.
_tprintf(_T("Serial Number: "));
dwData = pCertContext->pCertInfo->SerialNumber.cbData;
for (DWORD n = 0; n < dwData; n++)
{
_tprintf(_T("%02x "),
pCertContext->pCertInfo->SerialNumber.pbData[dwData - (n + 1)]);
}
_tprintf(_T("\n"));
// Get Issuer name size.
if (!(dwData = CertGetNameString(pCertContext,
CERT_NAME_SIMPLE_DISPLAY_TYPE,
CERT_NAME_ISSUER_FLAG,
NULL,
NULL,
0)))
{
_tprintf(_T("CertGetNameString failed.\n"));
__leave;
}
// Allocate memory for Issuer name.
szName = (LPTSTR)LocalAlloc(LPTR, dwData * sizeof(TCHAR));
if (!szName)
{
_tprintf(_T("Unable to allocate memory for issuer name.\n"));
__leave;
}
// Get Issuer name.
if (!(CertGetNameString(pCertContext,
CERT_NAME_SIMPLE_DISPLAY_TYPE,
CERT_NAME_ISSUER_FLAG,
NULL,
szName,
dwData)))
{
_tprintf(_T("CertGetNameString failed.\n"));
__leave;
}
// print Issuer name.
_tprintf(_T("Issuer Name: %s\n"), szName);
LocalFree(szName);
szName = NULL;
// Get Subject name size.
if (!(dwData = CertGetNameString(pCertContext,
CERT_NAME_SIMPLE_DISPLAY_TYPE,
0,
NULL,
NULL,
0)))
{
_tprintf(_T("CertGetNameString failed.\n"));
__leave;
}
// Allocate memory for subject name.
szName = (LPTSTR)LocalAlloc(LPTR, dwData * sizeof(TCHAR));
if (!szName)
{
_tprintf(_T("Unable to allocate memory for subject name.\n"));
__leave;
}
// Get subject name.
if (!(CertGetNameString(pCertContext,
CERT_NAME_SIMPLE_DISPLAY_TYPE,
0,
NULL,
szName,
dwData)))
{
_tprintf(_T("CertGetNameString failed.\n"));
__leave;
}
// Print Subject Name.
_tprintf(_T("Subject Name: %s\n"), szName);
fReturn = TRUE;
}
__finally
{
if (szName != NULL) LocalFree(szName);
}
return fReturn;
}
LPWSTR AllocateAndCopyWideString(LPCWSTR inputString)
{
LPWSTR outputString = NULL;
outputString = (LPWSTR)LocalAlloc(LPTR,
(wcslen(inputString) + 1) * sizeof(WCHAR));
if (outputString != NULL)
{
lstrcpyW(outputString, inputString);
}
return outputString;
}
BOOL GetProgAndPublisherInfo(PCMSG_SIGNER_INFO pSignerInfo,
PSPROG_PUBLISHERINFO Info)
{
BOOL fReturn = FALSE;
PSPC_SP_OPUS_INFO OpusInfo = NULL;
DWORD dwData;
BOOL fResult;
__try
{
// Loop through authenticated attributes and find
// SPC_SP_OPUS_INFO_OBJID OID.
for (DWORD n = 0; n < pSignerInfo->AuthAttrs.cAttr; n++)
{
if (lstrcmpA(SPC_SP_OPUS_INFO_OBJID,
pSignerInfo->AuthAttrs.rgAttr[n].pszObjId) == 0)
{
// Get Size of SPC_SP_OPUS_INFO structure.
fResult = CryptDecodeObject(ENCODING,
SPC_SP_OPUS_INFO_OBJID,
pSignerInfo->AuthAttrs.rgAttr[n].rgValue[0].pbData,
pSignerInfo->AuthAttrs.rgAttr[n].rgValue[0].cbData,
0,
NULL,
&dwData);
if (!fResult)
{
_tprintf(_T("CryptDecodeObject failed with %x\n"),
GetLastError());
__leave;
}
// Allocate memory for SPC_SP_OPUS_INFO structure.
OpusInfo = (PSPC_SP_OPUS_INFO)LocalAlloc(LPTR, dwData);
if (!OpusInfo)
{
_tprintf(_T("Unable to allocate memory for Publisher Info.\n"));
__leave;
}
// Decode and get SPC_SP_OPUS_INFO structure.
fResult = CryptDecodeObject(ENCODING,
SPC_SP_OPUS_INFO_OBJID,
pSignerInfo->AuthAttrs.rgAttr[n].rgValue[0].pbData,
pSignerInfo->AuthAttrs.rgAttr[n].rgValue[0].cbData,
0,
OpusInfo,
&dwData);
if (!fResult)
{
_tprintf(_T("CryptDecodeObject failed with %x\n"),
GetLastError());
__leave;
}
// Fill in Program Name if present.
if (OpusInfo->pwszProgramName)
{
Info->lpszProgramName =
AllocateAndCopyWideString(OpusInfo->pwszProgramName);
}
else
Info->lpszProgramName = NULL;
// Fill in Publisher Information if present.
if (OpusInfo->pPublisherInfo)
{
switch (OpusInfo->pPublisherInfo->dwLinkChoice)
{
case SPC_URL_LINK_CHOICE:
Info->lpszPublisherLink =
AllocateAndCopyWideString(OpusInfo->pPublisherInfo->pwszUrl);
break;
case SPC_FILE_LINK_CHOICE:
Info->lpszPublisherLink =
AllocateAndCopyWideString(OpusInfo->pPublisherInfo->pwszFile);
break;
default:
Info->lpszPublisherLink = NULL;
break;
}
}
else
{
Info->lpszPublisherLink = NULL;
}
// Fill in More Info if present.
if (OpusInfo->pMoreInfo)
{
switch (OpusInfo->pMoreInfo->dwLinkChoice)
{
case SPC_URL_LINK_CHOICE:
Info->lpszMoreInfoLink =
AllocateAndCopyWideString(OpusInfo->pMoreInfo->pwszUrl);
break;
case SPC_FILE_LINK_CHOICE:
Info->lpszMoreInfoLink =
AllocateAndCopyWideString(OpusInfo->pMoreInfo->pwszFile);
break;
default:
Info->lpszMoreInfoLink = NULL;
break;
}
}
else
{
Info->lpszMoreInfoLink = NULL;
}
fReturn = TRUE;
break; // Break from for loop.
} // lstrcmp SPC_SP_OPUS_INFO_OBJID
} // for
}
__finally
{
if (OpusInfo != NULL) LocalFree(OpusInfo);
}
return fReturn;
}
BOOL GetDateOfTimeStamp(PCMSG_SIGNER_INFO pSignerInfo, SYSTEMTIME* st)
{
BOOL fResult;
FILETIME lft, ft;
DWORD dwData;
BOOL fReturn = FALSE;
// Loop through authenticated attributes and find
// szOID_RSA_signingTime OID.
for (DWORD n = 0; n < pSignerInfo->AuthAttrs.cAttr; n++)
{
if (lstrcmpA(szOID_RSA_signingTime,
pSignerInfo->AuthAttrs.rgAttr[n].pszObjId) == 0)
{
// Decode and get FILETIME structure.
dwData = sizeof(ft);
fResult = CryptDecodeObject(ENCODING,
szOID_RSA_signingTime,
pSignerInfo->AuthAttrs.rgAttr[n].rgValue[0].pbData,
pSignerInfo->AuthAttrs.rgAttr[n].rgValue[0].cbData,
0,
(PVOID)&ft,
&dwData);
if (!fResult)
{
_tprintf(_T("CryptDecodeObject failed with %x\n"),
GetLastError());
break;
}
// Convert to local time.
FileTimeToLocalFileTime(&ft, &lft);
FileTimeToSystemTime(&lft, st);
fReturn = TRUE;
break; // Break from for loop.
} //lstrcmp szOID_RSA_signingTime
} // for
return fReturn;
}
BOOL GetTimeStampSignerInfo(PCMSG_SIGNER_INFO pSignerInfo, PCMSG_SIGNER_INFO* pCounterSignerInfo)
{
PCCERT_CONTEXT pCertContext = NULL;
BOOL fReturn = FALSE;
BOOL fResult;
DWORD dwSize;
__try
{
*pCounterSignerInfo = NULL;
// Loop through unathenticated attributes for
// szOID_RSA_counterSign OID.
for (DWORD n = 0; n < pSignerInfo->UnauthAttrs.cAttr; n++)
{
if (lstrcmpA(pSignerInfo->UnauthAttrs.rgAttr[n].pszObjId,
szOID_RSA_counterSign) == 0)
{
// Get size of CMSG_SIGNER_INFO structure.
fResult = CryptDecodeObject(ENCODING,
PKCS7_SIGNER_INFO,
pSignerInfo->UnauthAttrs.rgAttr[n].rgValue[0].pbData,
pSignerInfo->UnauthAttrs.rgAttr[n].rgValue[0].cbData,
0,
NULL,
&dwSize);
if (!fResult)
{
_tprintf(_T("CryptDecodeObject failed with %x\n"),
GetLastError());
__leave;
}
// Allocate memory for CMSG_SIGNER_INFO.
*pCounterSignerInfo = (PCMSG_SIGNER_INFO)LocalAlloc(LPTR, dwSize);
if (!*pCounterSignerInfo)
{
_tprintf(_T("Unable to allocate memory for timestamp info.\n"));
__leave;
}
// Decode and get CMSG_SIGNER_INFO structure
// for timestamp certificate.
fResult = CryptDecodeObject(ENCODING,
PKCS7_SIGNER_INFO,
pSignerInfo->UnauthAttrs.rgAttr[n].rgValue[0].pbData,
pSignerInfo->UnauthAttrs.rgAttr[n].rgValue[0].cbData,
0,
(PVOID)*pCounterSignerInfo,
&dwSize);
if (!fResult)
{
_tprintf(_T("CryptDecodeObject failed with %x\n"),
GetLastError());
__leave;
}
fReturn = TRUE;
break; // Break from for loop.
}
}
}
__finally
{
// Clean up.
if (pCertContext != NULL) CertFreeCertificateContext(pCertContext);
}
return fReturn;
}