VerifyData(3)VerifyData(3)NAME
VerifyData, CSSM_VerifyData, CSP_VerifyData - Verify input buffer data
(CDSA)
SYNOPSIS
# 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 DataBuf‐
Count, CSSM_ALGORITHMS DigestAlgorithm, const CSSM_DATA *Signature)
LIBRARY
Common Security Services Manager library (libcssm.so)
API PARAMETERS
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 num‐
ber 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 combina‐
tion digest/encryption algorithm. A pointer to a CSSM_DATA structure
which contains the signature and the size of the signature.
SPI PARAMETERS
The handle that describes the add-in cryptographic service provider
module used to perform up calls to CSSM for the memory functions man‐
aged by CSSM. 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 DigestAlgo‐
rithm 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 repre‐
sent an error condition.
ERRORS
Errors are described in the CDSA technical standard. See
CDSA_intro(3). CSSMERR_CSP_INPUT_LENGTH_ERROR CSSMERR_CSP_VER‐
IFY_FAILED CSSMERR_CSP_INVALID_SIGNATURE CSS‐
MERR_CSP_INVALID_DIGEST_ALGORITHM
SEE ALSO
Books
Intel CDSA Application Developer's Guide (see CDSA_intro(3))
Reference Pages
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)