DecryptDataUpdate

NAME
  DecryptDataUpdate,
  CSSM_DecryptDataUpdate,
  CSP_DecryptDataUpdate - Continue the staged decryption process (CDSA)

SYNOPSIS
  # include <cssm.h>

   API:
       CSSM_RETURN CSSMAPI CSSM_DecryptDataUpdate
       (CSSM_CC_HANDLE CCHandle,
       const CSSM_DATA *CipherBufs,
       uint32 CipherBufCount,
       CSSM_DATA_PTR ClearBufs,
       uint32 ClearBufCount,
       uint32 *bytesDecrypted)
   SPI:
       CSSM_RETURN CSSMCSPI CSP_DecryptDataUpdate
       (CSSM_CSP_HANDLE CSPHandle,
       CSSM_CC_HANDLE CCHandle,
       const CSSM_DATA *CipherBufs,
       uint32 CipherBufCount,
       CSSM_DATA_PTR ClearBufs,
       uint32 ClearBufCount,
       uint32 *bytesDecrypted)

LIBRARY
  Common Security Services Manager library (CDSA$INCSSM300_SHR.EXE)

API 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.

SPI PARAMETER
  CSPHandle (input)
          The handle that describes the add-in cryptographic service
          provider module used to perform calls to CSSM for the memory
          functions managed by CSSM.

DESCRIPTION
  This function continues the staged decryption process over all data
  in the set of input buffers. There can be algorithm-specific and
  token-specific rules restricting the lengths of data in
  CSSM_DecryptUpdate() calls, but multiple input buffers are supported.
  The minimum number of buffers required to contain the resulting plain
  text is produced as output. Excess output buffer space is not
  remembered across staged decryption calls. Each staged call begins
  filling one or more new output buffers. The CSSM_QuerySize()
  (CSSM API), or CSP_QuerySize() (CSP SPI), function can be used to
  estimate the output buffer size required for each update call.

NOTES FOR API
  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,
  preallocated output buffer, the caller must provide an array of one
  or more CSSM_DATA structures, each 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 deallocating the
  memory when it is no longer needed. In-place decryption can be done
  by supplying the same input and output buffers.

NOTES FOR SPI
  The output is returned to the caller as specified in  Buffer
  Management for Cryptographic Services.

RETURN VALUE
  A CSSM_RETURN value indicating success or specifying a particular
  error condition. The value CSSM_OK indicates success. All other
  values represent an error condition.

ERRORS
  Errors are described in the CDSA technical standard.  See CDSA.

  None specific to this call.

SEE ALSO
  Books

  Intel CDSA Application Developer's Guide (see CDSA)

  Other Help Topics

  Functions for the CSSM API:

      CSSM_QuerySize
      CSSM_DecryptData
      CSSM_DecryptDataInit
      CSSM_DecryptDataFinal

  Functions for the CSP SPI:

      CSP_QuerySize
      CSP_DecryptData
      CSP_DecryptDataInit
      CSP_DecryptDataFinal