PFN_CERT_DLL_OPEN_STORE_PROV_FUNC callback function (wincrypt.h)

Article
10/13/2021

The CertDllOpenStoreProv function is implemented by a store-provider and is used to open a store. This function is called by the CertOpenStore function.

Note The first five parameters are identical to the matching parameters in CertOpenStore.

Syntax

PFN_CERT_DLL_OPEN_STORE_PROV_FUNC PfnCertDllOpenStoreProvFunc;

BOOL PfnCertDllOpenStoreProvFunc(
  [in]      LPCSTR lpszStoreProvider,
  [in]      DWORD dwEncodingType,
  [in]      HCRYPTPROV_LEGACY hCryptProv,
  [in]      DWORD dwFlags,
  [in]      const void *pvPara,
  [in]      HCERTSTORE hCertStore,
  [in, out] PCERT_STORE_PROV_INFO pStoreProvInfo
)
{...}

Parameters

[in] lpszStoreProvider

A pointer to a null-terminated ANSI string that contains the store provider type.

The following values represent the predefined store types. The store provider type determines the contents of the pvPara parameter and the use and meaning of the high word of the dwFlags parameter. Additional store providers can be installed or registered by using the CryptInstallOIDFunctionAddress or CryptRegisterOIDFunction function. For more information about adding store providers, see Extending CertOpenStore Functionality.

Provider identifier	Description	pvPara contents
CERT_STORE_PROV_MEMORY sz_CERT_STORE_PROV_MEMORY	Creates a certificate store in cached memory. No certificates, certificate revocation lists (CRLs), or certificate trust lists (CTLs) are initially loaded into the store. Typically used to create a temporary store. Any addition of certificates, CRLs, or CTLs or changes in properties of certificates, CRLs, or CTLs in a memory store are not automatically saved. They can be saved to a file or to a memory BLOB by using CertSaveStore.	Not used.
CERT_STORE_PROV_FILE	Initializes the store with certificates, CRLs, and CTLs read from a specified open file. This provider expects the file to contain only a serialized store and not either PKCS #7 signed messages or a single encoded certificate. The file pointer must be positioned at the beginning of the serialized store information. After the data in the serialized store has been loaded into the certificate store, the file pointer is positioned at the beginning of any data that can follow the serialized store data in the file. If CERT_FILE_STORE_COMMIT_ENABLE is set in dwFlags, the file handle is duplicated and the store is always committed as a serialized store. The file is not closed when the store is closed.	A pointer to the handle of a file opened with CreateFile.
CERT_STORE_PROV_FILENAME_A	Initializes the store with certificates, CRLs, and CTLs from a file. The provider opens the file and first attempts to read the file as a serialized store, then as a PKCS #7 signed message, and finally as a single encoded certificate. The dwEncodingType parameter must contain the encoding types to be used with both messages and certificates. If the file contains an X.509 encoded certificate, the open operation fails with GetLastError and returns ERROR_ACCESS_DENIED. If the CERT_FILE_STORE_COMMIT_ENABLE flag is set in dwFlags, the dwCreationDisposition value passed to CreateFile is as follows: If the CERT_STORE_CREATE_NEW_FLAG flag is set, CreateFile uses CREATE_NEW. If the CERT_STORE_OPEN_EXISTING_FLAG flag is set, CreateFile uses OPEN_EXISTING. For all other settings of dwFlags, CreateFile uses OPEN_ALWAYS. If dwFlags includes CERT_FILE_STORE_COMMIT_ENABLE, the file is committed as either a PKCS #7 or a serialized store depending on the file type opened. If the file was empty or if the file name has either a .p7c or .spc extension, the file is committed as a PKCS #7. Otherwise, the file is committed as a serialized store.	A pointer to null-terminated ANSI string that contains the name of an existing, unopened file.
CERT_STORE_PROV_FILENAME CERT_STORE_PROV_FILENAME_W sz_CERT_STORE_PROV_FILENAME sz_CERT_STORE_PROV_FILENAME_W	Same as CERT_STORE_PROV_FILENAME_A.	A pointer to null-terminated Unicode string that contains the name of an existing, unopened file.
CERT_STORE_PROV_COLLECTION sz_CERT_STORE_PROV_COLLECTION	Opens a store that will be a collection of other stores. Stores are added to or removed from the collection by using CertAddStoreToCollection and CertRemoveStoreFromCollection. When a store is added to a collection, all certificates, CRLs, and CTLs in that store become available to searches or enumerations of the collection store. The high word of dwFlags is set to zero.	Must be NULL.
CERT_STORE_PROV_REG	Initializes the store with certificates, CRLs, and CTLs from a registry subkey. This provider opens or creates the registry subkeys Certificates, CRLs, and CTLs under the key passed in pvPara. The input key is not closed by the provider. Before returning, the provider opens its own copy of the key passed in pvPara. If CERT_STORE_READONLY_FLAG is set in the low word of dwFlags, registry subkeys are opened by using the RegOpenKey with KEY_READ_ACCESS. Otherwise, registry subkeys are created by using RegCreateKey with KEY_ALL_ACCESS. Any changes to the contents of the opened store are immediately persisted to the registry. However, if CERT_STORE_READONLY_FLAG is set in the low word of dwFlags, any attempt to add to the contents of the store or to change a context's property results in an error with GetLastError returning the E_ACCESSDENIED code.	The handle of an open registry key.
CERT_STORE_PROV_SYSTEM_A	Initializes the store with certificates, CRLs, and CTLs from the specified system store. The system store is a logical, collection store that consists of one or more physical stores. A physical store associated with a system store is registered with the CertRegisterPhysicalStore function. After the system store is opened, all of the physical stores that are associated with it are also opened by calls to CertOpenStore and are added to the system store collection by using the CertAddStoreToCollection function. The high word of dwFlags indicates the system store location, usually set to CERT_SYSTEM_STORE_CURRENT_USER. For details about registry locations, see dwFlags later in this topic and System Store Locations. Some system store locations can be opened remotely; for more information, see System Store Locations.	A pointer to a null-terminated ANSI string that contains a system store name, such as "My" or "Root".
CERT_STORE_PROV_SYSTEM CERT_STORE_PROV_SYSTEM_W sz_CERT_STORE_PROV_SYSTEM sz_CERT_STORE_PROV_SYSTEM_W	Same as CERT_STORE_PROV_SYSTEM_A.	A pointer to a null-terminated Unicode string that contains a system store name, such as "My" or "Root".
CERT_STORE_PROV_SYSTEM_REGISTRY_A	Initializes the store with certificates, CRLs, and CTLs from a physical registry store. The physical store is not opened as a collection store. Enumerations and searches go through only the certificates, CRLs, and CTLs in that one physical store. The high word of dwFlags indicates the system store location, usually set to CERT_SYSTEM_STORE_CURRENT_USER. For more information, see dwFlags later in this topic. Some system store locations can be open remotely; for more information, see System Store Locations.	A pointer to a null-terminated ANSI string that contains a system store name, such as "My" or "Root".
CERT_STORE_PROV_SYSTEM_REGISTRY CERT_STORE_PROV_SYSTEM_REGISTRY_W sz_CERT_STORE_PROV_SYSTEM_REGISTRY sz_CERT_STORE_PROV_SYSTEM_REGISTRY_W	Same as CERT_STORE_PROV_SYSTEM_REGISTRY_A.	A pointer to a null-terminated Unicode string that contains a system store name, such as "My" or "Root".
CERT_STORE_PROV_PHYSICAL CERT_STORE_PROV_PHYSICAL_W sz_CERT_STORE_PROV_PHYSICAL sz_CERT_STORE_PROV_PHYSICAL_W	Initializes the store with certificates, CRLs, and CTLs from a specified physical store that is a member of a logical system store. Two names are separated with an intervening backslash (\), for example "Root.LocalMachine". Here, "Root" is the name of the system store and ".LocalMachine" is the name of the physical store. The system and physical store names cannot contain any backslashes. The high word of dwFlags indicates the system store location, usually CERT_SYSTEM_STORE_CURRENT_USER. For more information, see dwFlags later in this topic. Some physical store locations can be opened remotely.	A pointer to a null-terminated Unicode string that contains both the system store name and physical names.
CERT_STORE_PROV_MSG	Initializes the store with certificates, CRLs, and CTLs from the specified cryptographic message. The dwEncodingType parameter must contain the encoding types used with both messages and certificates.	An HCRYPTMSG handle of the encoded message, returned by a call to CryptMsgOpenToDecode.
CERT_STORE_PROV_PKCS7 sz_CERT_STORE_PROV_PKCS7	Initializes the store with certificates, CRLs, and CTLs from an encoded PKCS #7 signed message. The dwEncodingType parameter must specify the encoding types to be used with both messages and certificates.	A pointer to a CRYPT_DATA_BLOB structure that represents the encoded message.
CERT_STORE_PROV_SERIALIZED sz_CERT_STORE_PROV_SERIALIZED	Initializes the store with certificates, CRLs, and CTLs from a memory location that contains a serialized store.	A pointer to a CRYPT_DATA_BLOB structure that contains the serialized memory BLOB.
CERT_STORE_PROV_LDAP CERT_STORE_PROV_LDAP_W sz_CERT_STORE_PROV_LDAP sz_CERT_STORE_PROV_LDAP_W	Initializes the store with certificates, CRLs, and CTLs from the results of an LDAP query. To perform write operations on the store, the query string must specify a BASE query with no filter and a single attribute.	If the dwFlags parameter contains the CERT_LDAP_STORE_OPENED_FLAG flag, this is the address of a CERT_LDAP_STORE_OPENED_PARA structure that specifies the established LDAP session to use. Otherwise, this is a pointer to a null-terminated Unicode string that contains the LDAP query string. For more information about LDAP query strings, see LDAP Dialect.
CERT_STORE_PROV_SMART_CARD CERT_STORE_PROV_SMART_CARD_W sz_CERT_STORE_PROV_SMART_CARD sz_CERT_STORE_PROV_SMART_CARD_W	Not currently used.

[in] dwEncodingType

Specifies the certificate encoding type and message encoding type. Encoding is used only when the dwSaveAs parameter of the CertSaveStore function contains CERT_STORE_SAVE_AS_PKCS7. Otherwise, the dwEncodingType parameter is not used.

This parameter is only applicable when the CERT_STORE_PROV_MSG, CERT_STORE_PROV_PKCS7, or CERT_STORE_PROV_FILENAME provider type is specified in the lpszStoreProvider parameter. For all other provider types, this parameter is unused and should be set to zero.

This parameter can be a combination of one or more of the following values.

Value	Meaning
PKCS_7_ASN_ENCODING 65536 (0x10000)	Specifies PKCS #7 message encoding.
X509_ASN_ENCODING 1 (0x1)	Specifies X.509 certificate encoding.

[in] hCryptProv

A handle to a cryptographic provider. This parameter can be NULL.

[in] dwFlags

These values consist of high-word and low-word values combined by using a bitwise-OR operation.

The low-word portion of dwFlags controls a variety of general characteristics of the certificate store opened. This portion can be used with all store provider types. The low-word portion of dwFlags can be one of the following values.

Value	Meaning
CERT_STORE_CREATE_NEW_FLAG	Create a new store if one does not exist. This function should fail if the store already exists. If neither CERT_STORE_OPEN_EXISTING_FLAG nor CERT_STORE_CREATE_NEW_FLAG is set, open an existing store or create and open a store if it does not already exist.
CERT_STORE_DEFER_CLOSE_UNTIL_LAST_FREE_FLAG	Defer closing of the store's provider until all certificates, CRLs, or CTLs obtained from the store are no longer in use. The store is actually closed when the last certificate, CRL, or CTL obtained from the store is freed. Any changes made to properties of these certificates, CRLs, and CTLs, even after the call to this function, must be persisted. If this flag is not set and certificates, CRLs, or CTLs obtained from the store are still in use, any changes to the properties of those certificates, CRLs, and CTLs must not be persisted. If this function is called with CERT_CLOSE_STORE_FORCE_FLAG, CERT_STORE_DEFER_CLOSE_UNTIL_LAST_FREE_FLAG must be ignored. When this flag is set and a non-NULL HCRYPTPROV value is passed, that provider will continue to be used even after the call to this function.
CERT_STORE_DELETE_FLAG	The store is deleted instead of being opened. This function returns FALSE for both success and failure of the deletion. To indicate the success of the deletion, call SetLastError with zero. To indicate failure of the deletion, call SetLastError with the appropriate error code.
CERT_STORE_ENUM_ARCHIVED_FLAG	Normally, an enumeration of all certificates in the store will ignore any certificate with the CERT_ARCHIVED_PROP_ID property set. If this flag is set, an enumeration of the certificates in the store will contain all of the certificates in the store, including those that have the CERT_ARCHIVED_PROP_ID property.
CERT_STORE_MAXIMUM_ALLOWED	Open the store with the maximum set of allowed permissions. If this flag is specified, registry stores are first opened with write access and if that fails, they are reopened with read-only access.
CERT_STORE_NO_CRYPT_RELEASE_FLAG	This flag is not used when the hCryptProv parameter is NULL. This flag is only valid when a non-NULL CSP handle is passed as the hCryptProv parameter. Setting this flag prevents the automatic release of a non-default CSP when the certificate store is closed.
CERT_STORE_OPEN_EXISTING_FLAG	Only open an existing store. If the store does not exist, the function fails.
CERT_STORE_READONLY_FLAG	Open the store in read-only mode. Any attempt to change the contents of the store will result in an error. When this flag is set and a registry based store provider is being used, the registry subkeys are opened by using RegOpenKey with KEY_READ_ACCESS. Otherwise, the registry subkeys are created by using RegCreateKey with KEY_ALL_ACCESS.
CERT_STORE_SET_LOCALIZED_NAME_FLAG	If this flag is supported, the provider sets the store's CERT_STORE_LOCALIZED_NAME_PROP_ID property. The localized name can be retrieved by calling the CertGetStoreProperty function with dwPropID set to CERT_STORE_LOCALIZED_NAME_PROP_ID. This flag is supported for providers of types CERT_STORE_PROV_FILENAME, CERT_STORE_PROV_SYSTEM, CERT_STORE_PROV_SYSTEM_REGISTRY, and CERT_STORE_PROV_PHYSICAL_W.
CERT_STORE_SHARE_CONTEXT_FLAG	When opening a store multiple times, you can set this flag to ensure efficient memory use by reusing the memory for the encoded parts of a certificate, CRL, or CTL context across the opened instances of the stores.
CERT_STORE_UPDATE_KEYID_FLAG	Lists of key identifiers exist within CurrentUser and LocalMachine. These key identifiers have properties much like the properties of certificates. If the CERT_STORE_UPDATE_KEYID_FLAG is set, then for every key identifier in the store's location that has a CERT_KEY_PROV_INFO_PROP_ID property, that property is automatically updated from the key identifier property CERT_KEY_PROV_INFO_PROP_ID or the CERT_KEY_IDENTIFIER_PROP_ID of the certificate related to that key identifier.
CERT_STORE_BACKUP_RESTORE_FLAG	Use the thread's SE_BACKUP_NAME and SE_RESTORE_NAME privileges to open registry or file-based system stores. If the thread does not have these privileges, this function must fail with an access denied error.

The CERT_STORE_PROV_SYSTEM, CERT_STORE_PROV_SYSTEM_REGISTRY, and CERT_STORE_PROV_PHYSICAL provider types use the following high words of dwFlags to specify system store registry locations:

CERT_SYSTEM_STORE_CURRENT_SERVICE

CERT_SYSTEM_STORE_CURRENT_USER

CERT_SYSTEM_STORE_CURRENT_USER_GROUP_POLICY

CERT_SYSTEM_STORE_LOCAL_MACHINE

CERT_SYSTEM_STORE_LOCAL_MACHINE_ENTERPRISE

CERT_SYSTEM_STORE_LOCAL_MACHINE_GROUP_POLICY

CERT_SYSTEM_STORE_SERVICES

CERT_SYSTEM_STORE_USERS

By default, a system store location is opened relative to the HKEY_CURRENT_USER, HKEY_LOCAL_MACHINE, or HKEY_USERS predefined registry key. For more information, see System Store Locations.

The following high-word flags override this default behavior.

Value	Meaning
CERT_SYSTEM_STORE_RELOCATE_FLAG	When set, pvPara must contain a pointer to a CERT_SYSTEM_STORE_RELOCATE_PARA structure rather than a string. The structure indicates both the name of the store and its location in the registry.
CERT_SYSTEM_STORE_UNPROTECTED_FLAG	By default, when the CurrentUser "Root" store is opened, any SystemRegistry roots not on the protected root list are deleted from the cache before this function returns. When this flag is set, this default is overridden and all of the roots in the SystemRegistry are returned and no check of the protected root list is made.

The CERT_STORE_PROV_REGISTRY provider uses the following high-word flags.

Value	Meaning
CERT_REGISTRY_STORE_SERIALIZED_FLAG	The CERT_STORE_PROV_REG provider saves certificates, CRLs, and CTLs in a single, serialized store subkey instead of performing the default save operation. The default is that each certificate, CRL, or CTL is saved as a separate registry subkey under the appropriate subkey. This flag is mainly used for stores downloaded from the group policy template (GPT), such as the CurrentUserGroupPolicy and LocalMachineGroupPolicy stores. When CERT_REGISTRY_STORE_SERIALIZED_FLAG is set, store additions, deletions, or property changes are not persisted until there is a call to either CertCloseStore or CertControlStore using CERT_STORE_CTRL_COMMIT.
CERT_REGISTRY_STORE_REMOTE_FLAG	pvPara contains a handle to a registry key on a remote computer. To access a registry key on a remote computer, security permissions on the remote computer must be set to allow access. For more information, see Remarks.

Value

Meaning

CERT_REGISTRY_STORE_SERIALIZED_FLAG

The CERT_STORE_PROV_REG provider saves certificates, CRLs, and CTLs in a single, serialized store subkey instead of performing the default save operation. The default is that each certificate, CRL, or CTL is saved as a separate registry subkey under the appropriate subkey.

This flag is mainly used for stores downloaded from the group policy template (GPT), such as the CurrentUserGroupPolicy and LocalMachineGroupPolicy stores.

When CERT_REGISTRY_STORE_SERIALIZED_FLAG is set, store additions, deletions, or property changes are not persisted until there is a call to either CertCloseStore or CertControlStore using CERT_STORE_CTRL_COMMIT.

CERT_REGISTRY_STORE_REMOTE_FLAG

pvPara contains a handle to a registry key on a remote computer. To access a registry key on a remote computer, security permissions on the remote computer must be set to allow access. For more information, see Remarks.

The CERT_STORE_PROV_FILE and CERT_STORE_PROV_FILENAME provider types use the following high-word flags.

Value	Meaning
CERT_FILE_STORE_COMMIT_ENABLE	Setting this flag commits any additions to the store or any changes made to properties of contexts in the store to the file store either when CertCloseStore is called or when CertControlStore is called with CERT_STORE_CONTROL_COMMIT. CertOpenStore fails with E_INVALIDARG if both CERT_FILE_STORE_COMMIT_ENABLE and CERT_STORE_READONLY_FLAG are set in dwFlags.

The CERT_STORE_PROV_LDAP provider type uses the following high-word flags.

Value	Meaning
CERT_LDAP_STORE_SIGN_FLAG	To provide integrity required by some applications, digitally sign all LDAP traffic to and from an LDAP server by using the Kerberos authentication protocol.
CERT_LDAP_STORE_OPENED_FLAG	Use this flag to use an existing LDAP session. When this flag is specified, the pvPara parameter is the address of a CERT_LDAP_STORE_OPENED_PARA structure that contains information about the LDAP session to use.
CERT_LDAP_STORE_AREC_EXCLUSIVE_FLAG	Performs an A-Record-only DNS lookup on the URL named in the pvPara parameter. This prevents false DNS queries from being generated when resolving URL host names. Use this flag when passing a host name as opposed to a domain name for the pvPara parameter.
CERT_LDAP_STORE_UNBIND_FLAG	Use this flag with the CERT_LDAP_STORE_OPENED_FLAG flag to cause the LDAP session to be unbound when the store is closed. The system will unbind the LDAP session by using the ldap_unbind function when the store is closed.

[in] pvPara

A 32-bit value that can contain additional information for this function. The contents of this parameter depends on the value of the lpszStoreProvider and other parameters.

[in] hCertStore

The handle of the store in memory that has been opened and can be used to make calls to other store-related API calls, such as CertAddSerializedElementToStore.

[in, out] pStoreProvInfo

A pointer to the CERT_STORE_PROV_INFO structure to be updated. The data structure has been zeroed, and cbSize set before the call.

The cStoreProvFunc member of the CERT_STORE_PROV_INFO structure is the count of callback functions that are implemented and should be set last. After cStoreProvFunc is set, all subsequent store calls, such as CertAddEncodedCertificateToStore, will call the appropriate provider callback function.

Return value

TRUE if successful; otherwise, FALSE.

Requirements

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

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