NAME

CSSM_DecryptDataUpdate

SYNOPSIS

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

DESCRIPTION

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_DecryptUpdate calls.

PARAMETERS

CCHandle (input)

The handle that describes the context of this cryptographic operation used to link to the CSP-managed information.

CipherBufs (input)

A pointer to a vector of CSSM_DATA structures that contain the data to be operated on.

CipherBufCount (input)

The number of CipherBufs.

ClearBufs (output)

A pointer to a vector of CSSM_DATA structures that contain the decrypted data resulting from the decryption operation.

ClearBufCount (input)

The number of ClearBufs.

bytesDecrypted (output)

A pointer to uint32 for the size of the decrypted data in bytes.

RETURN VALUE

A CSSM return value. This function returns CSSM_OK if successful, and returns an error code if an error has occurred.

ERRORS

CSSM_CSP_INVALID_CONTEXT_HANDLE

Invalid context handle.

CSSM_CSP_INVALID_DATA_POINTER

Invalid input or output CSSM_DATA pointer.

CSSM_CSP_INVALID_DATA_COUNT

Invalid input or output data count; data count cannot be 0.

CSSM_CSP_INVALID_DATA

Invalid input or output CSSM_DATA buffer.

CSSM_CSP_NOT_ENOUGH_BUFFER

The output buffer is not big enough.

CSSM_CSP_MEMORY_ERROR

Not enough memory to allocate.

CSSM_CSP_STAGED_OPERATION_UNSUPPORTED

Staged operation unsupported.

CSSM_CSP_STAGED_OPERATION_FAILED

Staged Cryptographic operation failed.

CSSM_CSP_VECTOROFBUFS_UNSUPPORTED

Supports only a single buffer of input.

Comments

The output is returned to the caller either by filling the caller-specified buffer or by using the application's declared memory allocation functions to allocate buffer space. To specify a specific, pre-allocated output buffer, the caller must provide an array of one or more CSSM_DATA structures each one containing a Length field value greater than zero and a non-NULL Data pointer field value. To specify automatic output buffer allocation by the CSP, the caller must provide an array of one or more CSSM_DATA structures each containing a Length field value equal to zero and a NULL Data pointer field value. The application is always responsible for de-allocating the memory when it is no longer needed. If the CSSM_DATA_PTR parameter is NULL (that is, does not point to an array of CSSM_DATA structures) or the number of CSSM_DATA structures is specified as zero, the error code CSSM_CSP_INVALID_DATA_POINTER is returned. In-place decryption can be done by supplying the same input and output buffers.

SEE ALSO

CSSM_DecryptData, CSSM_DecryptDataInit,
CSSM_DecryptDataFinal, CSSM_QuerySize