CMSG_ENVELOPED_ENCODE_INFO (Compact 2013)

3/28/2014

This structure contains information needed to encode an enveloped message. It is passed to CryptMsgOpenToEncode if dwMsgType is CMSG_ENVELOPED.

Syntax

typedef struct _CMSG_ENVELOPED_ENCODE_INFO {
  DWORD cbSize;
  HCRYPTPROV hCryptProv;
  CRYPT_ALGORITHM_IDENTIFIER ContentEncryptionAlgorithm;
  void* pvEncryptionAuxInfo;
  DWORD cRecipients;
  PCERT_INFO* rgpRecipients;
  PCMSG_RECIPIENT_ENCODE_INFO rgCmsRecipients;
  DWORD cCertEncoded;
  PCERT_BLOB rgCertEncoded;
  DWORD cCrlEncoded;
  PCRL_BLOB rgCrlEncoded;
  DWORD cAttrCertEncoded;
  PCERT_BLOB rgAttrCertEncoded;
  DWORD cUnprotectedAttr;
  PCRYPT_ATTRIBUTE rgUnprotectedAttr;
} CMSG_ENVELOPED_ENCODE_INFO, *PCMSG_ENVELOPED_ENCODE_INFO;

Members

• cbSize
  Size of this structure in bytes.

• hCryptProv
  Designates a handle to the cryptographic service provider (CSP) used to do content encryption, recipient key encryption, and export. The private keys of hCryptProv are not used.

  Unless there is a strong reason for passing in a specific cryptographic provider in hCryptProv, pass zero to use the default RSA or DSS provider.

• ContentEncryptionAlgorithm
  CRYPT_ALGORITHM_IDENTIFIER structure contains the signature algorithm type and any associated additional parameters in encoded form.

  The pszObjId member of the structure specifies the algorithm used to encrypt the message contents.

  The following encryption algorithms require an encoded eight-byte initialization vector (IV) in the Parameters member of structure. For details, see CryptSetKeyParam.

  Value	Description
  CALG_DES	szOID_OIWSEC_desCBC
  CALG_3DES	szOID_RSA_DES_EDE3_CBC

  If the cbData member of the Parameters member is zero, an ASN.1 encoded OCTET STRING containing the IV is generated using CryptGenRandom.

  The szOID_RSA_RC2CBC (CALG_RC2) algorithm requires the pbData member of Parameters to be an encoded CRYPT_RC2_CBC_PARAMETERS structure. If the cbData member of the Parameters member is zero, an ASN.1 encoded CRYPT_RC2_CBC_PARAMETERS is generated with a default value of 40 for the dwVersion member. This sets the default key length to 40 bits. This default key length can be overridden with pvEncryptionAuxInfo pointing to a CMSG_RC2_AUX_INFO structure containing the desired key length.

  Note

  On decryption, if an IV exists, CryptSetKeyParam is called with the IV before decryption begins.

• pvEncryptionAuxInfo
  Pointer to a structure depending on the encryption algorithm.

  Value	Description
  RC2	CMSG_RC2_AUX_INFO
  RC4	CMSG_RC4_AUX_INFO
  SP3 or compatible	CMSG_SP3_COMPATIBLE_AUX_INFO
  All other encryption algorithms	NULL

• cRecipients
  Number of elements in the rgpRecipients or rgCmsRecipients array.

• rgpRecipients
  Pointer to an array of CERT_INFO structures, each containing a recipient's certificate Issuer, SerialNumber, and SubjectPublicKeyInfo. This array can only be used for recipients identified by their Issuer and serial number. If rgpRecipients is not NULL, rgCmsRecipients must be NULL.

• rgCmsRecipients
  Pointer to an array of CMSG_RECIPIENT_ENCODE_INFO structures, each containing recipient information. If rgCmsRecipients is not NULL, rgpRecipients must be NULL. CMSG_ENVELOPED_ENCODE_INFO_HAS_CMS_FIELDS must be defined to reference this field.

• cCertEncoded
  DWORD indicating the number of encoded certificates in the rgCertEncoded array. CMSG_ENVELOPED_ENCODE_INFO_HAS_CMS_FIELDS must be defined to reference this field.

• rgCertEncoded
  Pointer to an array of CERT_BLOB structures. CMSG_ENVELOPED_ENCODE_INFO_HAS_CMS_FIELDS must be defined to reference this field.

• cCrlEncoded
  DWORD indicating the number of encoded CRLs in the rgCRLEncoded array. CMSG_ENVELOPED_ENCODE_INFO_HAS_CMS_FIELDS must be defined to reference this field.

• rgCrlEncoded
  Pointer to an array of CRL_BLOB structures. CMSG_ENVELOPED_ENCODE_INFO_HAS_CMS_FIELDS must be defined to reference this field.

• cAttrCertEncoded
  DWORD indicating the number of encoded certificate attributes in the rgAttrCertEncoded array. CMSG_ENVELOPED_ENCODE_INFO_HAS_CMS_FIELDS must be defined to reference this field.

• rgAttrCertEncoded
  Pointer to an array of CRYPT_ATTRIBUTE structures. CMSG_ENVELOPED_ENCODE_INFO_HAS_CMS_FIELDS must be defined to reference this member.

• cUnprotectedAttr
  DWORD indicating the number of unprotected attributes in the rgUnprotectedAttr array. CMSG_ENVELOPED_ENCODE_INFO_HAS_CMS_FIELDS must be defined to reference this field.

• rgUnprotectedAttr
  Pointer to an array of CRYPT_ATTRIBUTE structures. CMSG_ENVELOPED_ENCODE_INFO_HAS_CMS_FIELDS must be defined to reference this field.

Remarks

CMSG_ENVELOPED_ENCODE_INFO_HAS_CMS_FIELDS must be defined to reference the following structure members:

rgCmsRecipients

cCertEncoded

rgCertEncoded

cCrlEncoded

rgCrlEncoded

cAttrCertEncoded

rgAttrCertEncoded

cUnprotectedAttr

rgUnprotectedAttr

Requirements

See Also

Reference

Cryptography Structures
CERT_INFO
CRYPT_ALGORITHM_IDENTIFIER