CryptGetMessageSignerCount function

The CryptGetMessageSignerCount function returns the number of signers of a signed message.

Syntax

LONG WINAPI CryptGetMessageSignerCount(
  _In_       DWORD dwMsgEncodingType,
  _In_ const BYTE  *pbSignedBlob,
  _In_       DWORD cbSignedBlob
);

Parameters

dwMsgEncodingType [in]

Specifies the encoding type used. It is always acceptable to specify both the certificate and message encoding types by combining them with a bitwise-OR operation as shown in the following example:

X509_ASN_ENCODING | PKCS_7_ASN_ENCODING

Currently defined encoding types are:

• X509_ASN_ENCODING
• PKCS_7_ASN_ENCODING

pbSignedBlob [in]

A pointer to a buffer containing the signed message.

cbSignedBlob [in]

The size, in bytes, of the signed message.

Return value

Returns the number of signers of a signed message, zero when there are no signers, and minus one (–1) for an error.

For extended error information, call GetLastError. The following error code is most commonly returned.

If the function fails, GetLastError may return an Abstract Syntax Notation One (ASN.1) encoding/decoding error. For information about these errors, see ASN.1 Encoding/Decoding Return Values.

Examples

See Example C Program: Setting and Getting Certificate Store Properties.

Requirements

See also

Simplified Message Functions

CryptVerifyMessageSignature