This is based on RFC 4253, section 6.4, but with hmac-md5 variants removed because they have 
reached the end of their useful life.

Valid values: 

```
hmac******@****.***
hmac******@****.***
hmac-sha2-256
hmac-sha2-512
hmac-sha1
hmac-sha1-96
```

### Certificate-based authentication

			"X-Minio-Internal-Server-Side-Encryption-Sealed-Key":     "IAAfAMBdYor5tf/UlVaQvwYlw5yKbPBeQqfygqsfHqhu1wHD9KDAP4bw38AhL12prFTS23JbbR9Re5Qv26ZnlQ==",
			"X-Minio-Internal-Server-Side-Encryption-Seal-Algorithm": "DAREv2-HMAC-SHA256",
			"X-Minio-Internal-Server-Side-Encryption-Iv":             "coVfGS3I/CTrqexX5vUN+PQPoP9aUFiPYYrSzqTWfBA=",
		},
		ExpectedErr: nil,
	},
	{ // 1 - Valid HTTP headers but invalid metadata entries for bucket/object2

                }

                MessageDigest hmac = Crypto.getHMACT64(ntHash);
                hmac.update(Strings.getUNIBytes(this.username.toUpperCase()));
                hmac.update(Strings.getUNIBytes(this.domain.toUpperCase()));
                byte[] ntlmv2Hash = hmac.digest();
                hmac = Crypto.getHMACT64(ntlmv2Hash);
                hmac.update(chlng);
                hmac.update(this.clientChallenge);

	if err != nil {
		t.Fatal(err)
	}

// This is based on RFC 4253, section 6.4, but with hmac-md5 variants removed
// because they have reached the end of their useful life.
// https://cs.opensource.google/go/x/crypto/+/refs/tags/v0.22.0:ssh/common.go;l=85
var supportedMACs = []string{
	"hmac******@****.***", "hmac******@****.***", "hmac-sha2-256", "hmac-sha2-512", "hmac-sha1", "hmac-sha1-96",
}

import (
	"bytes"
	"crypto"
	"crypto/hmac"
	"encoding/base64"
	"errors"
	"fmt"
	"hash"
	"sync"
	"time"

	"github.com/buger/jsonparser"
	"github.com/dustin/go-humanize"
	jwtgo "github.com/golang-jwt/jwt/v4"
	jsoniter "github.com/json-iterator/go"
)

// SigningMethodHMAC - Implements the HMAC-SHA family of signing methods signing methods

e9dQpeeEJWgKUa/8R61oCy1mFwIg==", "X-Minio-Internal-Server-Side-Encryption-S3-Sealed-Key": "IAAfAPFYRDkHVirJBJxBixNj3PLWt78dFuUTyTLIdLG820J7XqLPBO4gpEEEWw/DoTsJIb+apnaem+rKtQ1h3Q==", "X-Minio-Internal-Server-Side-Encryption-Seal-Algorithm": "DAREv2-HMAC-SHA256", "content-type": "application/octet-stream", "etag": "20000f00e2c3709dc94905c6ce31e1cadbd1c064e14acdcd44cf0ac2db777eeedd88d639fcd64de16851ade8b21a9a1a"}, Parts: []ObjectPartInfo{{ETag: "", Number: 1, Size: 3430, ActualSize: 3398}}, Erasure:...

// along with this program.  If not, see <http://www.gnu.org/licenses/>.

package kms

import (
	"context"
	"crypto/aes"
	"crypto/cipher"
	"crypto/hmac"
	"encoding/base64"
	"encoding/json"
	"errors"
	"strconv"
	"strings"
	"sync/atomic"

	"github.com/secure-io/sio-go/sioutil"
	"golang.org/x/crypto/chacha20"
	"golang.org/x/crypto/chacha20poly1305"

	contentLengthCondStr := `["content-length-range", 1024, 1048576]`
	// Add the algorithm condition, only accept AWS SignV4 Sha256.
	algorithmConditionStr := `["eq", "$x-amz-algorithm", "AWS4-HMAC-SHA256"]`
	// Add the date condition, only accept the current date.
	dateConditionStr := fmt.Sprintf(`["eq", "$x-amz-date", "%s"]`, t.Format(iso8601DateFormat))
	// Add the credential string, only accept the credential passed.

		expected        map[string]string
	}{
		{
			metadata: map[string]string{
				"Authorization":        "AWS4-HMAC-SHA256 <cred_string>",
				"X-Amz-Content-Sha256": "",
				"Content-Encoding":     "",
			},
			expected: map[string]string{
				"Authorization":        "AWS4-HMAC-SHA256 <cred_string>",
				"X-Amz-Content-Sha256": "",
				"Content-Encoding":     "",
			},
		},
		{