VerifyData

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

SYNOPSIS
  # include <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
  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.

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

  DataBufCount (input)
          The number of DataBufs to be verified.

  DigestAlgorithm (input)
          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.

  Signature (input)
          A pointer to a CSSM_DATA structure which contains the
          signature and the size of the signature.

SPI PARAMETERS
  CSPHandle (input)
          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.

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

DESCRIPTION
  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
  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_INPUT_LENGTH_ERROR
       CSSMERR_CSP_VERIFY_FAILED
       CSSMERR_CSP_INVALID_SIGNATURE
       CSSMERR_CSP_INVALID_DIGEST_ALGORITHM

SEE ALSO
  Books

  Intel CDSA Application Developer's Guide (see CDSA)

  Other Help Topics

  Functions for the CSSM API:

      CSSM_SignData
      CSSM_VerifyDataInit
      CSSM_VerifyDataUpdate
      CSSM_VerifyDataFinal

  Functions for the CSP SPI:

      CSP_SignData
      CSP_VerifyDataInit
      CSP_VerifyDataUpdate
      CSP_VerifyDataFinal