provider: add STSTokenProvider

pkg/credentials/provider/ststoken_provider.go

@@ -0,0 +1,29 @@
+package provider
+
+import (
+	"context"
+	"errors"
+)
+
+type STSTokenProvider struct {
+	cred *Credentials
+}
+
+func NewSTSTokenProvider(accessKeyId, accessKeySecret, securityToken string) *STSTokenProvider {
+	return &STSTokenProvider{
+		cred: &Credentials{
+			AccessKeyId:     accessKeyId,
+			AccessKeySecret: accessKeySecret,
+			SecurityToken:   securityToken,
+		},
+	}
+}
+
+func (a *STSTokenProvider) Credentials(ctx context.Context) (*Credentials, error) {
+	if a.cred.AccessKeyId == "" || a.cred.AccessKeySecret == "" || a.cred.SecurityToken == "" {
+		return nil, NewNotEnableError(
+			errors.New("AccessKeyId, AccessKeySecret or SecurityToken is empty"))
+	}
+
+	return a.cred, nil
+}