CMSG_CTRL_KEY_AGREE_DECRYPT_PARA structure (wincrypt.h)

The CMSG_CTRL_KEY_AGREE_DECRYPT_PARA structure contains information about a key agreement recipient.

Syntax

typedef struct _CMSG_CTRL_KEY_AGREE_DECRYPT_PARA {
  DWORD                          cbSize;
  union {
    HCRYPTPROV        hCryptProv;
    NCRYPT_KEY_HANDLE hNCryptKey;
  } DUMMYUNIONNAME;
  DWORD                          dwKeySpec;
  PCMSG_KEY_AGREE_RECIPIENT_INFO pKeyAgree;
  DWORD                          dwRecipientIndex;
  DWORD                          dwRecipientEncryptedKeyIndex;
  CRYPT_BIT_BLOB                 OriginatorPublicKey;
} CMSG_CTRL_KEY_AGREE_DECRYPT_PARA, *PCMSG_CTRL_KEY_AGREE_DECRYPT_PARA;

Members

cbSize

The size, in bytes, of this data structure.

DUMMYUNIONNAME

DUMMYUNIONNAME.hCryptProv

A handle to the cryptographic service provider (CSP) used to do the recipient key encryption and export. If NULL, the provider specified in CMSG_ENVELOPED_ENCODE_INFO is used. The CNG function NCryptIsKeyHandle is called to determine the union choice.

DUMMYUNIONNAME.hNCryptKey

A handle to the CNG CSP used to do the recipient key encryption and export. The CNG function NCryptIsKeyHandle is called to determine the union choice. New encrypt algorithms are only supported in CNG functions. The CNG function NCryptTranslateHandle will be called to convert the CryptoAPI CSP hCryptProv choice where necessary. We recommend that applications pass, to the hNCryptKey member, the CNG CSP handle that is returned from the NCryptOpenKey function.

dwKeySpec

Specifies the encrypted key. The encrypted key is the result of encrypting the content-encryption key. This member is not used when the hNCryptKey member is used.

pKeyAgree

A pointer to a CMSG_KEY_AGREE_RECIPIENT_INFO structure.

dwRecipientIndex

Indicates a specific recipient in an array of recipients.

dwRecipientEncryptedKeyIndex

Indicates a specific encrypted key in an array of encrypted keys.

OriginatorPublicKey

A CRYPT_BIT_BLOB structure that contains the sender's public key information.

Requirements