Edit

Share via

CMSG_CTRL_KEY_TRANS_DECRYPT_PARA structure (wincrypt.h)

  • Article

The CMSG_CTRL_KEY_TRANS_DECRYPT_PARA structure contains information about a key transport message recipient.

Syntax

typedef struct _CMSG_CTRL_KEY_TRANS_DECRYPT_PARA {
  DWORD                          cbSize;
  union {
    HCRYPTPROV        hCryptProv;
    NCRYPT_KEY_HANDLE hNCryptKey;
  } DUMMYUNIONNAME;
  DWORD                          dwKeySpec;
  PCMSG_KEY_TRANS_RECIPIENT_INFO pKeyTrans;
  DWORD                          dwRecipientIndex;
} CMSG_CTRL_KEY_TRANS_DECRYPT_PARA, *PCMSG_CTRL_KEY_TRANS_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 for a specific recipient by using that recipient's public key. This member is not used when the hNCryptKey member is used.

pKeyTrans

A pointer to a CMSG_KEY_TRANS_RECIPIENT_INFO structure.

dwRecipientIndex

Indicates a specific recipient in any array of recipients.

Requirements

Requirement Value
Minimum supported client Windows XP [desktop apps only]
Minimum supported server Windows Server 2003 [desktop apps only]
Header wincrypt.h