Windows CE 3.0

This function installs a previously acquired HCRYPTPROV context to be used as a default context. The values of two input parameters, wDefaultType and pvDefaultPara, specify where the default context is used.

BOOL WINAPI CryptInstallDefaultContext(
DWORD dwDefaultType,
const void *pvDefaultPara,
DWORD dwFlags,
void *pvReserved,


[in] HCRYPTPROV handle to be used as the default context. This handle must have already been created using the CryptAcquireContext function.
[in] Sets the use of the default provider handle. The following table shows the possible values for the dwDefaultType parameter.
Value Description
CRYPT_DEFAULT_CONTEXT_CERT_SIGN_OID Installs a default HCRYPTPROV handle used to verify a certificate signature. pvDefaultPara points to the szOID value of the certificate signature algorithm; for example, szOID_OIWSEC_md5RSA. If pvDefaultPara is NULL, the HCRYPTPROV handle is used to verify all certificate signatures. Note, pvDefaultPara cannot be NULL when CRYPT_DEFAULT_CONTEXT_PROCESS_FLAG is set.
CRYPT_DEFAULT_CONTEXT_MULTI_CERT_SIGN_OID Same as CRYPT_DEFAULT_CONTEXT_CERT_SIGN_OID. However, the default HCRYPT2PROV structure is to be used for multiple signature szOID values. The pvDefaultPara parameter points to a CRYPT_DEFAULT_CONTEXT_MULTI_OID_PARA structure containing an array of szOID pointers.
[in] Pointer to the szOID value of the certificate signature algorithm or to an array of szOID values defined in the CRYPT_DEFAULT_CONTEXT_MULTI_OID_PARA structure. It can be NULL if the dwDefaultType parameter is CRYPT_DEFAULT_CONTEXT_CERT_SIGN_OID and the default HCRYPTPROV value is used to verify all certificate signatures.
[in] Flags that determine the way the provider is released and, if applicable, all threads are shown in the following table.
Value Description
CRYPT_DEFAULT_CONTEXT_AUTO_RELEASE_FLAG The hCryptProv value is released automatically when the process ends. The hCryptProv value is not released by a call to the CryptUninstallDefaultContext function if the function is called before process or thread exit.
CRYPT_DEFAULT_CONTEXT_PROCESS_FLAG The hCryptProv value is applicable to all threads in the process. This is the default flag.
[in] Reserved for future use.
[out] Pointer to the handle of the new default context.

Return Values

If the function succeeds, the return value is nonzero (TRUE) and the *phDefaultContext parameter is updated with the handle to be passed to the CryptUninstallDefaultContext function.

If the function fails, the return value is zero (FALSE).

For extended error information, call the GetLastError function.


By default, the installed HCRYPTPROV value is only applicable to the current // thread. Set CRYPT_DEFAULT_CONTEXT_PROCESS_FLAG to allow the HCRYPTPROV value to be used by all threads in the current process.

The installed HCRYPTPROV values are stack-ordered, thus the last installed HCRYPTPROV value is checked first. All thread-installed HCRYPTPROV values are checked before any process HCRYPTPROV values.

The installed HCRYPTPROV value remains available for default usage until the CryptUninstallDefaultContext function is called or the thread or process exits.

If CRYPT_DEFAULT_CONTEXT_AUTO_RELEASE_FLAG is set, then the HCRYPTPROV value is released by the CryptReleaseContext function at thread or process exit. The provider is not re-released if the CryptUninstallDefaultContext function was previously called.


Runs on Versions Defined in Include Link to
Windows CE OS 3.0 or later Wincrypt.h   Crypt32.lib
Note   This API is part of the complete Windows CE OS package as provided by Microsoft. The functionality of a particular platform is determined by the original equipment manufacturer (OEM) and some devices may not support this API.

See Also

HCRYPTPROV, CryptAcquireContext, CryptReleaseContext, CryptUninstallDefaultContext

 Last updated on Tuesday, July 13, 2004

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