int length = Math.min(key.length, BLOCK_LENGTH);
        for (int i = 0; i < length; i++) {
            ipad[i] = (byte) (key[i] ^ IPAD);
            opad[i] = (byte) (key[i] ^ OPAD);
        }
        for (int i = length; i < BLOCK_LENGTH; i++) {
            ipad[i] = IPAD;
            opad[i] = OPAD;
        }
        try {
            md5 = MessageDigest.getInstance("MD5");
        } catch (Exception ex) {

        for ( int i = 0; i < length; i++ ) {
            this.ipad[ i ] = (byte) ( key[ i ] ^ IPAD );
            this.opad[ i ] = (byte) ( key[ i ] ^ OPAD );
        }
        for ( int i = length; i < BLOCK_LENGTH; i++ ) {
            this.ipad[ i ] = IPAD;
            this.opad[ i ] = OPAD;
        }

        this.md5 = Crypto.getMD5();
        engineReset();
    }

# OPA Quickstart Guide [![Slack](https://slack.minio.io/slack?type=svg)](https://slack.minio.io)

OPA is a lightweight general-purpose policy engine that can be co-located with MinIO server, in this document we talk about how to use OPA HTTP API to authorize requests. It can be used with any type of credentials (STS based like OpenID or LDAP, regular IAM users or service accounts).

OPA is enabled through MinIO's Access Management Plugin feature.

## Get started

        int start = dstIndex;

        this.dataOffset = ( dstIndex - this.headerStart ) + 26; // 26 = off from here to pad

        this.pad = ( this.dataOffset - this.headerStart ) % 4;
        this.pad = this.pad == 0 ? 0 : 4 - this.pad;
        this.dataOffset += this.pad;

        SMBUtil.writeInt2(this.fid, dst, dstIndex);
        dstIndex += 2;
        SMBUtil.writeInt4(this.offset, dst, dstIndex);

		*a = oa
		return nil
	}

	*a = oa
	return nil
}

// Opa - implements opa policy agent calls.
type Opa struct {
	args   Args
	client *http.Client
}

// Enabled returns if opa is enabled.
func Enabled(kvs config.KVS) bool {
	return kvs.Get(URL) != ""
}

// LookupConfig lookup Opa from config, override with any ENVs.

	Compression compress.Config `json:"compress"`

	// OpenID configuration
	OpenID openid.Config `json:"openid"`

	// External policy enforcements.
	Policy struct {
		// OPA configuration.
		OPA opa.Args `json:"opa"`

		// Add new external policy enforcements here.
	} `json:"policy"`

	LDAPServerConfig xldap.LegacyConfig `json:"ldapserverconfig"`

		arm64SpecialOperand = map[string]arm64.SpecialOperand{}
		for opd := arm64.SPOP_BEGIN; opd < arm64.SPOP_END; opd++ {
			arm64SpecialOperand[opd.String()] = opd
		}

		// Handle some special cases.
		specialMapping := map[string]arm64.SpecialOperand{
			// The internal representation of CS(CC) and HS(LO) are the same.
			"CS": arm64.SPOP_HS,
			"CC": arm64.SPOP_LO,
		}
		for s, opd := range specialMapping {
			arm64SpecialOperand[s] = opd

    }


    @Override
    protected int readBytesWireFormat ( byte[] buffer, int bufferIndex ) throws SMBProtocolDecodingException {
        this.pad = this.pad1 = 0;
        if ( this.parameterCount > 0 ) {
            bufferIndex += this.pad = this.parameterOffset - ( bufferIndex - this.headerStart );

        bufferIndex += 4;

        int pad = bufferIndex - ( getHeaderStart() + securityBufferOffset );
        this.blob = new byte[securityBufferLength];
        System.arraycopy(buffer, getHeaderStart() + securityBufferOffset, this.blob, 0, securityBufferLength);
        bufferIndex += pad;
        bufferIndex += securityBufferLength;

        return bufferIndex - start;
    }

                pad = parameterOffset % PADDING_SIZE;
                pad = pad == 0 ? 0 : PADDING_SIZE - pad;
                parameterOffset += pad;
            }

            // caclulate parameterDisplacement before calculating new parameterCount
            parameterDisplacement += parameterCount;

            int available = maxBufferSize - parameterOffset - pad;