WTHelperCertCheckValidSignature function

[The WTHelperCertCheckValidSignature function is available for use in the operating systems specified in the Requirements section. It may be altered or unavailable in subsequent versions. For certificate verification, use the CertGetCertificateChain and CertVerifyCertificateChainPolicy functions. For Microsoft Authenticode technology signature verification, use the .NET Framework.]

The WTHelperCertCheckValidSignature function checks whether a signature is valid. It can be used by trust providers to get an initial assessment of the validity of a signature before calling the function pointed to by the pfnFinalPolicy member of a CRYPT_PROVIDER_FUNCTIONS structure.


HRESULT WTHelperCertCheckValidSignature(



A pointer to the CRYPT_PROVIDER_DATA structure that contains the signer and countersigner information.

Return Value

If the function succeeds, the function returns S_OK.

If the function fails, it returns an HRESULT value that indicates the error. For a list of possible error values, see WinVerifyTrust.


Minimum supported client Windows Vista, Windows XP with SP2 [desktop apps only]
Minimum supported server Windows Server 2003 [desktop apps only]
Target Platform Windows
Header wintrust.h
Library Wintrust.lib
DLL Wintrust.dll