VerifySignature function (sspi.h)

Article
02/22/2024

Verifies that a message signed by using the MakeSignature function was received in the correct sequence and has not been modified.

Syntax

KSECDDDECLSPEC SECURITY_STATUS SEC_ENTRY VerifySignature(
  [in]  PCtxtHandle    phContext,
  [in]  PSecBufferDesc pMessage,
  [in]  unsigned long  MessageSeqNo,
  [out] unsigned long  *pfQOP
);

Parameters

[in] phContext

A handle to the security context to use for the message.

[in] pMessage

Pointer to a SecBufferDesc structure that references a set of SecBuffer structures that contain the message and signature to verify. The signature is in a SecBuffer structure of type SECBUFFER_TOKEN.

[in] MessageSeqNo

Specifies the sequence number expected by the transport application, if any. If the transport application does not maintain sequence numbers, this parameter is zero.

[out] pfQOP

Pointer to a ULONG variable that receives package-specific flags that indicate the quality of protection.

Some security packages ignore this parameter.

Return value

If the function verifies that the message was received in the correct sequence and has not been modified, the return value is SEC_E_OK.

If the function determines that the message is not correct according to the information in the signature, the return value can be one of the following error codes.

Return code	Description
SEC_E_OUT_OF_SEQUENCE	The message was not received in the correct sequence.
SEC_E_MESSAGE_ALTERED	The message has been altered.
SEC_E_INVALID_HANDLE	The context handle specified by phContext is not valid.
SEC_E_INVALID_TOKEN	pMessage did not contain a valid SECBUFFER_TOKEN buffer, or contained too few buffers.
SEC_E_QOP_NOT_SUPPORTED	The quality of protection negotiated between the client and server did not include integrity checking.

Remarks

Warning

The VerifySignature function will fail if the message was signed using the RsaSignPssSha512 algorithm on a different version of Windows. For example, a message that was signed by calling the MakeSignature function on Windows 8 will cause the VerifySignature function on Windows 8.1 to fail.

Requirements

Requirement	Value
Minimum supported client	Windows XP [desktop apps only]
Minimum supported server	Windows Server 2003 [desktop apps only]
Target Platform	Windows
Header	sspi.h (include Security.h)
Library	Secur32.lib
DLL	Secur32.dll