kms: add more APIs and request/response types.

This commit adds support for more KMS APIs, like
creating and deleting enclaves and secret keys.

It also adds the generic `ListRequest` and `ListResponse`
types.

Signed-off-by: Andreas Auernhammer <[email protected]>

kms/crypto.go

@@ -0,0 +1,47 @@
+// Copyright 2023 - MinIO, Inc. All rights reserved.
+// Use of this source code is governed by the AGPLv3
+// license that can be found in the LICENSE file.
+
+package kms
+
+import (
+	"fmt"
+	"strconv"
+)
+
+// SecretKeyType defines the type of a secret key. Secret keys with
+// different types are not compatible since they may differ in the
+// encryption algorithm, key length, cipher mode, etc.
+type SecretKeyType uint
+
+// Supported secret key types.
+const (
+	// AES256 represents the AES-256-GCM secret key type.
+	AES256 SecretKeyType = iota + 1
+
+	// ChaCha20 represents the ChaCha20-Poly1305 secret key type.
+	ChaCha20
+)
+
+// String returns the string representation of the SecretKeyType.
+func (s SecretKeyType) String() string {
+	switch s {
+	case AES256:
+		return "AES256"
+	case ChaCha20:
+		return "ChaCha20"
+	default:
+		return "!INVALID:" + strconv.Itoa(int(s))
+	}
+}
+
+func secretKeyTypeFromString(s string) (SecretKeyType, error) {
+	switch s {
+	case "AES256":
+		return AES256, nil
+	case "ChaCha20":
+		return ChaCha20, nil
+	default:
+		return 0, fmt.Errorf("kms: key type '%s' is not supported", s)
+	}
+}

kms/internal/api/api.go

@@ -7,9 +7,29 @@ package api
 const (
 	PathStatus = "/v1/status"
 
+	PathEnclaveCreate   = "/v1/enclave/create/"
+	PathEnclaveDescribe = "/v1/enclave/describe/"
+	PathEnclaveDelete   = "/v1/enclave/delete/"
+	PathEnclaveList     = "/v1/enclave/list/"
+
+	PathSecretKeyCreate   = "/v1/key/create/"
+	PathSecretKeyDescribe = "/v1/key/describe/"
+	PathSecretKeyDelete   = "/v1/key/delete/"
+	PathSecretKeyList     = "/v1/key/list/"
 	PathSecretKeyGenerate = "/v1/key/generate/"
 	PathSecretKeyEncrypt  = "/v1/key/encrypt/"
 	PathSecretKeyDecrypt  = "/v1/key/decrypt/"
 
-	PathClusterStatus = "/v1/cluster/status"
+	PathClusterStatus  = "/v1/cluster/status"
+	PathClusterAdd     = "/v1/cluster/add/"
+	PathClusterRemove  = "/v1/cluster/remove/"
+	PathClusterBackup  = "/v1/cluster/backup"
+	PathClusterRestore = "/v1/cluster/restore"
+	PathClusterEdit    = "/v1/cluster/edit"
+)
+
+// API query parameters supported by KMS servers.
+const (
+	QueryListContinue = "continue"
+	QueryListLimit    = "limit"
 )

kms/iter.go

@@ -0,0 +1,75 @@
+// Copyright 2023 - MinIO, Inc. All rights reserved.
+// Use of this source code is governed by the AGPLv3
+// license that can be found in the LICENSE file.
+
+package kms
+
+import (
+	"context"
+	"io"
+)
+
+// Iter is an iterator over elements of type T. It turns
+// a paginated listing provided by the NextFn into a
+// continuous stream of items.
+type Iter[T any] struct {
+	// NextFn is a function that returns the next page from
+	// a paginated list.
+	NextFn func(context.Context, *ListRequest) (*ListResponse[T], error)
+
+	items      []T
+	prefix     string
+	continueAt string
+	limit      int
+	err        error
+}
+
+// SeekTo seeks to a specific position within the stream and returns the item
+// at this position.
+func (i *Iter[T]) SeekTo(ctx context.Context, req *ListRequest) (item T, err error) {
+	if i.err != nil && i.err != io.EOF {
+		return item, i.err
+	}
+
+	i.prefix = req.Prefix
+	i.continueAt = req.ContinueAt
+	i.limit = req.Limit
+
+	i.items, i.err = nil, nil
+	return i.Next(ctx)
+}
+
+// Next returns the next item from the stream or io.EOF at the end.
+// The context is used when Next has to fetch the next page of the
+// paginated listing.
+func (i *Iter[T]) Next(ctx context.Context) (item T, err error) {
+	if len(i.items) == 0 {
+		if i.err != nil {
+			return item, i.err
+		}
+
+		resp, err := i.NextFn(ctx, &ListRequest{
+			Prefix:     i.prefix,
+			ContinueAt: i.continueAt,
+			Limit:      i.limit,
+		})
+		if err != nil {
+			i.err = err
+			i.items = nil
+			return item, i.err
+		}
+
+		i.items, i.continueAt = resp.Items, resp.ContinueAt
+		if len(i.items) == 0 {
+			i.err = io.EOF
+			return item, i.err
+		}
+		if i.continueAt == "" {
+			i.err = io.EOF
+		}
+	}
+
+	item = i.items[0]
+	i.items = i.items[1:]
+	return item, nil
+}