//     Input: ClientKey, bucket, object, metadata, object_data
//     -              IV := Random({0,1}²⁵⁶)
//     -       ObjectKey := SHA256(ClientKey || Random({0,1}²⁵⁶))
//     -       KeyEncKey := HMAC-SHA256(ClientKey, IV || 'SSE-C' || 'DAREv2-HMAC-SHA256' || bucket || '/' || object)
//     -       SealedKey := DAREv2_Enc(KeyEncKey, ObjectKey)
//     - enc_object_data := DAREv2_Enc(ObjectKey, object_data)
//     -        metadata <- IV

	streamingContentSHA256        = "STREAMING-AWS4-HMAC-SHA256-PAYLOAD"
	streamingContentSHA256Trailer = "STREAMING-AWS4-HMAC-SHA256-PAYLOAD-TRAILER"
	signV4ChunkedAlgorithm        = "AWS4-HMAC-SHA256-PAYLOAD"
	signV4ChunkedAlgorithmTrailer = "AWS4-HMAC-SHA256-TRAILER"
	streamingContentEncoding      = "aws-chunked"
	awsTrailerHeader              = "X-Amz-Trailer"

//
// You should have received a copy of the GNU Affero General Public License
// along with this program.  If not, see <http://www.gnu.org/licenses/>.

package crypto

import (
	"bytes"
	"context"
	"crypto/hmac"
	"crypto/rand"
	"encoding/binary"
	"errors"
	"io"
	"path"

	"github.com/minio/minio/internal/fips"
	"github.com/minio/minio/internal/hash/sha256"
	"github.com/minio/minio/internal/logger"

	"github.com/minio/minio/internal/auth"
	"github.com/minio/minio/internal/hash/sha256"
	xhttp "github.com/minio/minio/internal/http"
)

// AWS Signature Version '4' constants.
const (
	signV4Algorithm = "AWS4-HMAC-SHA256"
	iso8601Format   = "20060102T150405Z"
	yyyymmdd        = "20060102"
)

type serviceType string

const (
	serviceS3  serviceType = "s3"
	serviceSTS serviceType = "sts"
)

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

	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"