rbd: add aws-sts-metdata encryption type

With Amazon STS and kubernetes cluster is configured with
OIDC identity provider, credentials to access Amazon KMS
can be fetched using oidc-token(serviceaccount token).
Each tenant/namespace needs to create a secret with aws region,
role and CMK ARN.
Ceph-CSI will assume the given role with oidc token and access
aws KMS, with given CMK to encrypt/decrypt DEK which will stored
in the image metdata.

Refer: https://docs.aws.amazon.com/STS/latest/APIReference/welcome.html
Resolves: #2879

Signed-off-by: Rakshith R <rar@redhat.com>

vendor/github.com/aws/smithy-go/rand/doc.go

@@ -0,0 +1,3 @@
+// Package rand provides utilities for creating and working with random value
+// generators.
+package rand

vendor/github.com/aws/smithy-go/rand/rand.go

@@ -0,0 +1,31 @@
+package rand
+
+import (
+	"crypto/rand"
+	"fmt"
+	"io"
+	"math/big"
+)
+
+func init() {
+	Reader = rand.Reader
+}
+
+// Reader provides a random reader that can reset during testing.
+var Reader io.Reader
+
+// Int63n returns a int64 between zero and value of max, read from an io.Reader source.
+func Int63n(reader io.Reader, max int64) (int64, error) {
+	bi, err := rand.Int(reader, big.NewInt(max))
+	if err != nil {
+		return 0, fmt.Errorf("failed to read random value, %w", err)
+	}
+
+	return bi.Int64(), nil
+}
+
+// CryptoRandInt63n returns a random int64 between zero and value of max
+// obtained from the crypto rand source.
+func CryptoRandInt63n(max int64) (int64, error) {
+	return Int63n(Reader, max)
+}

vendor/github.com/aws/smithy-go/rand/uuid.go

@@ -0,0 +1,87 @@
+package rand
+
+import (
+	"encoding/hex"
+	"io"
+)
+
+const dash byte = '-'
+
+// UUIDIdempotencyToken provides a utility to get idempotency tokens in the
+// UUID format.
+type UUIDIdempotencyToken struct {
+	uuid *UUID
+}
+
+// NewUUIDIdempotencyToken returns a idempotency token provider returning
+// tokens in the UUID random format using the reader provided.
+func NewUUIDIdempotencyToken(r io.Reader) *UUIDIdempotencyToken {
+	return &UUIDIdempotencyToken{uuid: NewUUID(r)}
+}
+
+// GetIdempotencyToken returns a random UUID value for Idempotency token.
+func (u UUIDIdempotencyToken) GetIdempotencyToken() (string, error) {
+	return u.uuid.GetUUID()
+}
+
+// UUID provides computing random UUID version 4 values from a random source
+// reader.
+type UUID struct {
+	randSrc io.Reader
+}
+
+// NewUUID returns an initialized UUID value that can be used to retrieve
+// random UUID version 4 values.
+func NewUUID(r io.Reader) *UUID {
+	return &UUID{randSrc: r}
+}
+
+// GetUUID returns a random UUID version 4 string representation sourced from the random reader the
+// UUID was created with. Returns an error if unable to compute the UUID.
+func (r *UUID) GetUUID() (string, error) {
+	var b [16]byte
+	if _, err := io.ReadFull(r.randSrc, b[:]); err != nil {
+		return "", err
+	}
+	r.makeUUIDv4(b[:])
+	return format(b), nil
+}
+
+// GetBytes returns a byte slice containing a random UUID version 4 sourced from the random reader the
+// UUID was created with. Returns an error if unable to compute the UUID.
+func (r *UUID) GetBytes() (u []byte, err error) {
+	u = make([]byte, 16)
+	if _, err = io.ReadFull(r.randSrc, u); err != nil {
+		return u, err
+	}
+	r.makeUUIDv4(u)
+	return u, nil
+}
+
+func (r *UUID) makeUUIDv4(u []byte) {
+	// 13th character is "4"
+	u[6] = (u[6] & 0x0f) | 0x40 // Version 4
+	// 17th character is "8", "9", "a", or "b"
+	u[8] = (u[8] & 0x3f) | 0x80 // Variant most significant bits are 10x where x can be either 1 or 0
+}
+
+// Format returns the canonical text representation of a UUID.
+// This implementation is optimized to not use fmt.
+// Example: 82e42f16-b6cc-4d5b-95f5-d403c4befd3d
+func format(u [16]byte) string {
+	// https://en.wikipedia.org/wiki/Universally_unique_identifier#Version_4_.28random.29
+
+	var scratch [36]byte
+
+	hex.Encode(scratch[:8], u[0:4])
+	scratch[8] = dash
+	hex.Encode(scratch[9:13], u[4:6])
+	scratch[13] = dash
+	hex.Encode(scratch[14:18], u[6:8])
+	scratch[18] = dash
+	hex.Encode(scratch[19:23], u[8:10])
+	scratch[23] = dash
+	hex.Encode(scratch[24:], u[10:])
+
+	return string(scratch[:])
+}