This command is used to verify a digital signature using the ECDSA algorithm. The signature must be created with one of the key-pairs from the crypto-utilities key management mechanism. Verification of a buffer can be done by ECDSAwithSHA or ECDSAwithSHA256, where the buffer to digest is given by the API. If a predigested message is used, verification occurs when the digest is passed in the verify command, instead of the buffer.

An example of sign and verify buffer:

_u16 configLen = 0;
_u8 buf[256];
_u8 verifyBuf[2048];
SlNetUtilCryptoCmdSignAttrib_t signAttrib;
SlNetUtilCryptoCmdVerifyAttrib_t verAttrib;
_i32 verifyResult;
_u16 resultLen;
_u8 messageBuf[1500]; 
_i16 Status;
signAttrib.Flags = 0;
signAttrib.ObjId = 3;
signAttrib.SigType = SL_NETUTIL_CRYPTO_SIG_SHAwECDSA; /* this is the only type supported */
configLen = 255;
Status = sl_NetUtilCmd(SL_NETUTIL_CRYPTO_CMD_SIGN_MSG, (_u8 *)&signAttrib, 
                       sizeof(SlNetUtilCryptoCmdSignAttrib_t),
                       messageBuf,  sizeof(messageBuf), buf, &configLen); 
if(0 > Status)
{
    /* error */
}
/* now verify the buffer */
memcpy(verifyBuf, messageBuf, sizeof(messageBuf));
memcpy(verifyBuf + sizeof(messageBuf), buf, configLen);
verAttrib.Flags = 0;
verAttrib.ObjId = 3;
verAttrib.SigType = SL_NETUTIL_CRYPTO_SIG_SHAwECDSA; /* this is the only type supported */
verAttrib.MsgLen = sizeof(messageBuf);
verAttrib.SigLen = configLen;
/* use the created keys to verify the signature from the previous step */
resultLen = 4;
Status = sl_NetUtilCmd(SL_NETUTIL_CRYPTO_CMD_VERIFY_MSG, (_u8 *)&verAttrib, 
                       sizeof(SlNetUtilCryptoCmdVerifyAttrib_t),
                       verifyBuf, sizeof(messageBuf) + configLen, 
                       (_u8 *)&verifyResult , &resultLen); 
if(0 > Status)
{
    /* error */
}