NAME    [Toc]    [Back]

       VerifyData, CSSM_VerifyData, CSP_VerifyData - Verify input
       buffer data (CDSA)

SYNOPSIS    [Toc]    [Back]

       # include <cdsa/cssm.h>

       API: CSSM_RETURN CSSMAPI  CSSM_VerifyData  (CSSM_CC_HANDLE
       CCHandle,  const CSSM_DATA *DataBufs, uint32 DataBufCount,
       CSSM_ALGORITHMS DigestAlgorithm, const  CSSM_DATA  *Signature)
    SPI:    CSSM_RETURN    CSSMCSPI    CSP_VerifyData
       (CSSM_CSP_HANDLE CSPHandle, CSSM_CC_HANDLE CCHandle, const
       CSSM_CONTEXT  *Context,  const CSSM_DATA *DataBufs, uint32
       DataBufCount,   CSSM_ALGORITHMS   DigestAlgorithm,   const
       CSSM_DATA *Signature)

LIBRARY    [Toc]    [Back]

       Common Security Services Manager library (libcssm.so)

API PARAMETERS    [Toc]    [Back]

       The  handle  that  describes  the  context of this cryptographic
 operation used to link to the CSP-managed information.
   A pointer to a vector of CSSM_DATA structures that
       contain the  data  to  be  operated  on.   The  number  of
       DataBufs  to  be  verified.   If  verifying just a digest,
       specifies the type of digest.  In this case,  the  context
       should only specify the encryption algorithm. If not verifying
 just a digest, it must be CSSM_ALGID_NONE.  In  this
       case,   the   context   should   specify  the  combination
       digest/encryption algorithm.  A  pointer  to  a  CSSM_DATA
       structure which contains the signature and the size of the
       signature.

SPI PARAMETERS    [Toc]    [Back]

       The handle that describes the add-in cryptographic service
       provider  module  used to perform up calls to CSSM for the
       memory functions managed by CSSM.  Pointer to CSSM_CONTEXT
       structure that describes the attributes with this context.

DESCRIPTION    [Toc]    [Back]

       This function verifies all data contained in  the  set  of
       input buffers based on the input signature.

       Verifying  can  include  digesting the data and decrypting
       the digest (from the  signature)  or  verifying  just  the
       digest   (already  calculated  by  the  application).   If
       digesting the data and decrypting  the  digest,  then  the
       context  should  specify  both digest and decryption algorithms
  (for  example,  CSSM_ALGID_MD5WithRSA).   In  this
       case,   the  DigestAlgorithm  parameter  must  be  set  to
       CSSM_ALGID_NONE. If signing just the digest, then the context
  should specify just the decryption algorithm and the
       DigestAlgorithm  parameter  should  specify  the  type  of
       digest  (for  example, CSSM_ALGID_MD5). Also, DataBufCount
       must be 1.

       If the signing algorithm is  not  reversible  or  strictly
       limits the size of the signed data, then the algorithm can
       specify verification without digesting.  In this case, the
       verify  operation  is  performed on the input data and the
       size of the  input  data  is  restricted  by  the  service
       provider.

RETURN VALUE    [Toc]    [Back]

       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    [Toc]    [Back]

       Errors  are described in the CDSA technical standard.  See
       CDSA_intro(3).     CSSMERR_CSP_INPUT_LENGTH_ERROR     CSSMERR_CSP_VERIFY_FAILED
  CSSMERR_CSP_INVALID_SIGNATURE CSSMERR_CSP_INVALID_DIGEST_ALGORITHM

SEE ALSO    [Toc]    [Back]

       Books

       Intel   CDSA   Application    Developer's    Guide    (see
       CDSA_intro(3))

       Reference Pages    [Toc]    [Back]

       Functions for the CSSM API:

       CSSM_SignData(3),   CSSM_VerifyDataInit(3),   CSSM_VerifyDataUpdate(3), CSSM_VerifyDataFinal(3)

       Functions for the CSP SPI:

       CSP_SignData(3), CSP_VerifyDataInit(3),  CSP_VerifyDataUpdate(3), CSP_VerifyDataFinal(3)



                                                    VerifyData(3)