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CTL_FIND_USAGE_PARA structure (wincrypt.h)

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The CTL_FIND_USAGE_PARA structure is a member of the CTL_FIND_SUBJECT_PARA structure and it is used by CertFindCTLInStore.

Syntax

typedef struct _CTL_FIND_USAGE_PARA {
  DWORD           cbSize;
  CTL_USAGE       SubjectUsage;
  CRYPT_DATA_BLOB ListIdentifier;
  PCERT_INFO      pSigner;
} CTL_FIND_USAGE_PARA, *PCTL_FIND_USAGE_PARA;

Members

cbSize

The size, in bytes, of this structure.

SubjectUsage

CTL_USAGE structure that includes a sequence of object identifiers to be matched when finding a certificate trust list (CTL).

A found CTL must contain all the usage object identifiers specified by the SubjectUsage member.

If the cUsageIdentifier member of this structure is zero, a CTL with any usage can be a match.

ListIdentifier

Specified to restrict a search to a particular signer CTL list. Normally the ListIdentifier member will be zero, indicating that any ListIdentifier can be matched. If it is not zero, this ListIdentifier and the ListIdentifier in a CTL must match.

To match only CTLs that have no ListIdentifier the cbData member of ListIdentifier is set to CTL_FIND_NO_LIST_ID_CBDATA.

A CTL uses a ListIdentifier to distinguish among multiple CTLs created by the same issuer with the same SubjectUsage.

pSigner

A pointer to a CERT_INFO structure that specifies the CTL signer to be matched. Only the issuer and serial number from the CERT_INFO are used to match a signer.

Set pSigner to NULL to match any signer. To match CTLs that do not have any signers, set pSigner to CTL_FIND_NO_SIGNER_PTR.

The CertEncodingType of the signer is obtained from the dwMsgAndCertEncodingType parameter of CertFindCTLInStore.

Requirements

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

See also

CERT_INFO

CRYPT_INTEGER_BLOB

CTL_FIND_SUBJECT_PARA

CTL_USAGE

CertFindCTLInStore