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/validation.go

@@ -0,0 +1,140 @@
+package smithy
+
+import (
+	"bytes"
+	"fmt"
+	"strings"
+)
+
+// An InvalidParamsError provides wrapping of invalid parameter errors found when
+// validating API operation input parameters.
+type InvalidParamsError struct {
+	// Context is the base context of the invalid parameter group.
+	Context string
+	errs    []InvalidParamError
+}
+
+// Add adds a new invalid parameter error to the collection of invalid
+// parameters. The context of the invalid parameter will be updated to reflect
+// this collection.
+func (e *InvalidParamsError) Add(err InvalidParamError) {
+	err.SetContext(e.Context)
+	e.errs = append(e.errs, err)
+}
+
+// AddNested adds the invalid parameter errors from another InvalidParamsError
+// value into this collection. The nested errors will have their nested context
+// updated and base context to reflect the merging.
+//
+// Use for nested validations errors.
+func (e *InvalidParamsError) AddNested(nestedCtx string, nested InvalidParamsError) {
+	for _, err := range nested.errs {
+		err.SetContext(e.Context)
+		err.AddNestedContext(nestedCtx)
+		e.errs = append(e.errs, err)
+	}
+}
+
+// Len returns the number of invalid parameter errors
+func (e *InvalidParamsError) Len() int {
+	return len(e.errs)
+}
+
+// Error returns the string formatted form of the invalid parameters.
+func (e InvalidParamsError) Error() string {
+	w := &bytes.Buffer{}
+	fmt.Fprintf(w, "%d validation error(s) found.\n", len(e.errs))
+
+	for _, err := range e.errs {
+		fmt.Fprintf(w, "- %s\n", err.Error())
+	}
+
+	return w.String()
+}
+
+// Errs returns a slice of the invalid parameters
+func (e InvalidParamsError) Errs() []error {
+	errs := make([]error, len(e.errs))
+	for i := 0; i < len(errs); i++ {
+		errs[i] = e.errs[i]
+	}
+
+	return errs
+}
+
+// An InvalidParamError represents an invalid parameter error type.
+type InvalidParamError interface {
+	error
+
+	// Field name the error occurred on.
+	Field() string
+
+	// SetContext updates the context of the error.
+	SetContext(string)
+
+	// AddNestedContext updates the error's context to include a nested level.
+	AddNestedContext(string)
+}
+
+type invalidParamError struct {
+	context       string
+	nestedContext string
+	field         string
+	reason        string
+}
+
+// Error returns the string version of the invalid parameter error.
+func (e invalidParamError) Error() string {
+	return fmt.Sprintf("%s, %s.", e.reason, e.Field())
+}
+
+// Field Returns the field and context the error occurred.
+func (e invalidParamError) Field() string {
+	sb := &strings.Builder{}
+	sb.WriteString(e.context)
+	if sb.Len() > 0 {
+		if len(e.nestedContext) == 0 || (len(e.nestedContext) > 0 && e.nestedContext[:1] != "[") {
+			sb.WriteRune('.')
+		}
+	}
+	if len(e.nestedContext) > 0 {
+		sb.WriteString(e.nestedContext)
+		sb.WriteRune('.')
+	}
+	sb.WriteString(e.field)
+	return sb.String()
+}
+
+// SetContext updates the base context of the error.
+func (e *invalidParamError) SetContext(ctx string) {
+	e.context = ctx
+}
+
+// AddNestedContext prepends a context to the field's path.
+func (e *invalidParamError) AddNestedContext(ctx string) {
+	if len(e.nestedContext) == 0 {
+		e.nestedContext = ctx
+		return
+	}
+	// Check if our nested context is an index into a slice or map
+	if e.nestedContext[:1] != "[" {
+		e.nestedContext = fmt.Sprintf("%s.%s", ctx, e.nestedContext)
+		return
+	}
+	e.nestedContext = ctx + e.nestedContext
+}
+
+// An ParamRequiredError represents an required parameter error.
+type ParamRequiredError struct {
+	invalidParamError
+}
+
+// NewErrParamRequired creates a new required parameter error.
+func NewErrParamRequired(field string) *ParamRequiredError {
+	return &ParamRequiredError{
+		invalidParamError{
+			field:  field,
+			reason: fmt.Sprintf("missing required field"),
+		},
+	}
+}