CSSM_DecryptDataUpdate

Purpose

This function updates the staged decrypt function. The CSSM_QuerySize function can be used to estimate the output buffer size required for each update call. There may be algorithm-specific and token-specific rules restricting the lengths of data in CSSM_DecryptDataUpdate calls. When working with U.S. exportable versions of the OCSF, the caller may be required to possess specific exemptions or privileges in order to allow this call to complete successfully.

Format

CSSM_RETURN CSSMAPI CSSM_DecryptDataUpdate 
              (CSSM_CC_HANDLE CCHandle,
              const CSSM_DATA_PTR CipherBufs,
              uint32 CipherBufCount,
              CSSM_DATA_PTR ClearBufs,
              uint32 ClearBufCount,
              uint32 *bytesDecrypted)

Parameters

Input

CCHandle: The handle that describes the context of this cryptographic operation used to link to the CSP-managed information.
CipherBufs: A pointer to a vector of CSSM_DATA structures that contain the data to be operated on.
CipherBufCount: The number of CipherBufs.
ClearBufCount: The number of ClearBufs.

Output

bytesDecrypted: A pointer to uint32 for the size of the decrypted data in bytes.
ClearBufs: A pointer to a vector of CSSM_DATA structures that contain the decrypted data resulting from the decryption operation.

Return Value

CSSM_OK if the function was successful. CSSM_FAIL if an error occurred. Use CSSM_GetError to determine the exact error.

Notes

The output can be obtained either by filling the caller-supplied buffer or using the application's memory allocation functions to allocate space, which the application must later free. If the output buffer pointer is NULL, an error code CSSM_CSP_INVALID_DATA_POINTER is returned. In-place decryption can be done by supplying the same input and output buffers.

Related Information

CSSM_DecryptData
CSSM_DecryptDataInit
CSSM_DecryptDataFinal
CSSM_QuerySize
CSSM_RequestCssmExemption