NAME
   DecryptData,
   CSSM_DecryptData,
   CSP_DecryptData   - Decrypt buffer data (CDSA)

 SYNOPSIS
   # include <cssm.h>

    API:
        CSSM_RETURN CSSMAPI CSSM_DecryptData
        (CSSM_CC_HANDLE CCHandle,
        const CSSM_DATA *CipherBufs,
        uint32 CipherBufCount,
        CSSM_DATA_PTR ClearBufs,
        uint32 ClearBufCount,
        uint32 *bytesDecrypted,
        CSSM_DATA_PTR RemData)
    SPI:
        CSSM_RETURN CSSMCSPI CSP_DecryptData
        (CSSM_CSP_HANDLE CSPHandle,
        CSSM_CC_HANDLE CCHandle,
        const CSSM_CONTEXT *Context,
        const CSSM_DATA *CipherBufs,
        uint32 CipherBufCount,
        CSSM_DATA_PTR ClearBufs,
        uint32 ClearBufCount,
        uint32 *bytesDecrypted,
        CSSM_DATA_PTR RemData,
        CSSM_PRIVILEGE Privilege)

 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 decrypted.

   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.

   RemData (output)
           A pointer to the CSSM_DATA structure for the remaining plain
           text if there is not enough buffer space available in the
           output data structures.

 SPI PARAMETERS
   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.

   Context (input)
           A pointer to CSSM_CONTEXT structure that describes the
           attributes with this context.

   Privilege (input)
           The export privilege to be applied during the cryptographic
           operation. This parameter is forwarded to the CSP after
           CSSM verifies the caller and service provider privilege set
           includes the specified PRIVILEGE.

 DESCRIPTION
   This function decrypts all data contained in the set of input buffers
   using information in the context. The CSSM_QuerySize() (CSSM API), or
   CSP_QuerySize() (CSP SPI), function can be used to estimate the output
   buffer size required. The minimum number of buffers required to contain
   the resulting plain text is produced as output.  If the plain text
   result does not fit within the set of output buffers, the remaining
   plain text is returned in the single output buffer RemData.

   The CSP can require that the cryptographic context include access
   credentials for authentication and authorization checks when using a
   private key or a secret key.

 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,
   pre-allocated 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.

        CSSMERR_CSP_BLOCK_SIZE_MISMATCH
        CSSMERR_CSP_OUTPUT_LENGTH_ERROR

 SEE ALSO
   Books

   Intel CDSA Application Developer's Guide (see CDSA)

   Other Help Topics

   Functions for the CSSM API:

       CSSM_QuerySize
       CSSM_EncryptData
       CSSM_DecryptDataInit
       CSSM_DecryptDataUpdate
       CSSM_DecryptDataFinal
       CSSM_DecryptP
       CSSM_DecryptDataInitP

   Functions for the CSP SPI:

       CSP_QuerySize
       CSP_EncryptData
       CSP_DecryptDataInit
       CSP_DecryptDataUpdate
       CSP_DecryptDataFinal