byte[] ipad = new byte[64];
        byte[] opad = new byte[64];

        for (int i = 0; i < key.length; i++) {
            ipad[i] = (byte) (key[i] ^ 0x36);
            opad[i] = (byte) (key[i] ^ 0x5c);
        }
        for (int i = key.length; i < 64; i++) {
            ipad[i] = 0x36;
            opad[i] = 0x5c;
        }

        md5.update(ipad);

        final 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 (final Exception ex) {

        final int length = Math.min(key.length, BLOCK_LENGTH);
        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();
    }

        MessageDigest md5 = MessageDigest.getInstance("MD5");
        byte[] ipad = new byte[64];
        byte[] opad = new byte[64];

        // HMACT64 specific: truncate key to 64 bytes if needed
        int keyLen = Math.min(key.length, 64);
        for (int i = 0; i < keyLen; i++) {
            ipad[i] = (byte) (key[i] ^ 0x36);
            opad[i] = (byte) (key[i] ^ 0x5c);
        }
        for (int i = keyLen; i < 64; i++) {

# 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

generation function does not produce unique values") } blocksize := hm.inner.BlockSize() hm.ipad = make([]byte, blocksize) hm.opad = make([]byte, blocksize) if len(key) > blocksize { // If key is too big, hash it. hm.outer.Write(key) key = hm.outer.Sum(nil) } copy(hm.ipad, key) copy(hm.opad, key) for i := range hm.ipad { hm.ipad[i] ^= 0x36 } for i := range hm.opad { hm.opad[i] ^= 0x5c } hm.inner.Write(hm.ipad) return hm } // MarkAsUsedInKDF records that this HMAC instance is used as part of a KDF....

generation function does not produce unique values") } blocksize := hm.inner.BlockSize() hm.ipad = make([]byte, blocksize) hm.opad = make([]byte, blocksize) if len(key) > blocksize { // If key is too big, hash it. hm.outer.Write(key) key = hm.outer.Sum(nil) } copy(hm.ipad, key) copy(hm.opad, key) for i := range hm.ipad { hm.ipad[i] ^= 0x36 } for i := range hm.opad { hm.opad[i] ^= 0x5c } hm.inner.Write(hm.ipad) return hm } // MarkAsUsedInKDF records that this HMAC instance is used as part of a KDF....

		*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.

		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

        final 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);