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/time/time.go

@@ -0,0 +1,134 @@
+package time
+
+import (
+	"context"
+	"fmt"
+	"math/big"
+	"strings"
+	"time"
+)
+
+const (
+	// dateTimeFormat is a IMF-fixdate formatted RFC3339 section 5.6
+	dateTimeFormatInput    = "2006-01-02T15:04:05.999999999Z"
+	dateTimeFormatInputNoZ = "2006-01-02T15:04:05.999999999"
+	dateTimeFormatOutput   = "2006-01-02T15:04:05.999Z"
+
+	// httpDateFormat is a date time defined by RFC 7231#section-7.1.1.1
+	// IMF-fixdate with no UTC offset.
+	httpDateFormat = "Mon, 02 Jan 2006 15:04:05 GMT"
+	// Additional formats needed for compatibility.
+	httpDateFormatSingleDigitDay             = "Mon, _2 Jan 2006 15:04:05 GMT"
+	httpDateFormatSingleDigitDayTwoDigitYear = "Mon, _2 Jan 06 15:04:05 GMT"
+)
+
+var millisecondFloat = big.NewFloat(1e3)
+
+// FormatDateTime formats value as a date-time, (RFC3339 section 5.6)
+//
+// Example: 1985-04-12T23:20:50.52Z
+func FormatDateTime(value time.Time) string {
+	return value.UTC().Format(dateTimeFormatOutput)
+}
+
+// ParseDateTime parses a string as a date-time, (RFC3339 section 5.6)
+//
+// Example: 1985-04-12T23:20:50.52Z
+func ParseDateTime(value string) (time.Time, error) {
+	return tryParse(value,
+		dateTimeFormatInput,
+		dateTimeFormatInputNoZ,
+		time.RFC3339Nano,
+		time.RFC3339,
+	)
+}
+
+// FormatHTTPDate formats value as a http-date, (RFC 7231#section-7.1.1.1 IMF-fixdate)
+//
+// Example: Tue, 29 Apr 2014 18:30:38 GMT
+func FormatHTTPDate(value time.Time) string {
+	return value.UTC().Format(httpDateFormat)
+}
+
+// ParseHTTPDate parses a string as a http-date, (RFC 7231#section-7.1.1.1 IMF-fixdate)
+//
+// Example: Tue, 29 Apr 2014 18:30:38 GMT
+func ParseHTTPDate(value string) (time.Time, error) {
+	return tryParse(value,
+		httpDateFormat,
+		httpDateFormatSingleDigitDay,
+		httpDateFormatSingleDigitDayTwoDigitYear,
+		time.RFC850,
+		time.ANSIC,
+	)
+}
+
+// FormatEpochSeconds returns value as a Unix time in seconds with with decimal precision
+//
+// Example: 1515531081.123
+func FormatEpochSeconds(value time.Time) float64 {
+	ms := value.UnixNano() / int64(time.Millisecond)
+	return float64(ms) / 1e3
+}
+
+// ParseEpochSeconds returns value as a Unix time in seconds with with decimal precision
+//
+// Example: 1515531081.123
+func ParseEpochSeconds(value float64) time.Time {
+	f := big.NewFloat(value)
+	f = f.Mul(f, millisecondFloat)
+	i, _ := f.Int64()
+	// Offset to `UTC` because time.Unix returns the time value based on system
+	// local setting.
+	return time.Unix(0, i*1e6).UTC()
+}
+
+func tryParse(v string, formats ...string) (time.Time, error) {
+	var errs parseErrors
+	for _, f := range formats {
+		t, err := time.Parse(f, v)
+		if err != nil {
+			errs = append(errs, parseError{
+				Format: f,
+				Err:    err,
+			})
+			continue
+		}
+		return t, nil
+	}
+
+	return time.Time{}, fmt.Errorf("unable to parse time string, %w", errs)
+}
+
+type parseErrors []parseError
+
+func (es parseErrors) Error() string {
+	var s strings.Builder
+	for _, e := range es {
+		fmt.Fprintf(&s, "\n * %q: %v", e.Format, e.Err)
+	}
+
+	return "parse errors:" + s.String()
+}
+
+type parseError struct {
+	Format string
+	Err    error
+}
+
+// SleepWithContext will wait for the timer duration to expire, or until the context
+// is canceled. Whichever happens first. If the context is canceled the
+// Context's error will be returned.
+func SleepWithContext(ctx context.Context, dur time.Duration) error {
+	t := time.NewTimer(dur)
+	defer t.Stop()
+
+	select {
+	case <-t.C:
+		break
+	case <-ctx.Done():
+		return ctx.Err()
+	}
+
+	return nil
+}