The CMSG_SIGNED_ENCODE_INFO structure is used for signed messages. This structure is passed to CryptMsgOpenToEncode for a value of CMSG_SIGNED in dwMsgType.
typedef struct _CMSG_SIGNED_ENCODE_INFO {
DWORD cbSize;
DWORD cSigners;
PCMSG_SIGNER_ENCODE_INFO rgSigners;
DWORD cCertEncoded;
PCERT_BLOB rgCertEncoded;
DWORD cCrlEncoded;
PCRL_BLOB rgCrlEncoded;
} CMSG_SIGNED_ENCODE_INFO, *PCMSG_SIGNED_ENCODE_INFO;
BLOB Structure, CMSG_SIGNER_ENCODE_INFO