ebssurrogate builds didn't keep up with recent optimizations to region encryption in the ebs builder, and that was causing bugs with the common ami region copy step

builder/amazon/ebssurrogate/builder.go

@@ -308,6 +308,7 @@ func (b *Builder) Run(ctx context.Context, ui packer.Ui, hook packer.Hook) (pack
 			EnableAMIENASupport:      b.config.AMIENASupport,
 			Architecture:             b.config.Architecture,
 			LaunchOmitMap:            b.config.LaunchMappings.GetOmissions(),
+			AMISkipBuildRegion:       b.config.AMISkipBuildRegion,
 		},
 		&awscommon.StepAMIRegionCopy{
 			AccessConfig:      &b.config.AccessConfig,

builder/amazon/ebssurrogate/step_register_ami.go

@@ -7,6 +7,7 @@ import (
 	"github.com/aws/aws-sdk-go/aws"
 	"github.com/aws/aws-sdk-go/service/ec2"
 	awscommon "github.com/hashicorp/packer/builder/amazon/common"
+	"github.com/hashicorp/packer/common/random"
 	confighelper "github.com/hashicorp/packer/helper/config"
 	"github.com/hashicorp/packer/helper/multistep"
 	"github.com/hashicorp/packer/packer"
@@ -22,6 +23,7 @@ type StepRegisterAMI struct {
 	Architecture             string
 	image                    *ec2.Image
 	LaunchOmitMap            map[string]bool
+	AMISkipBuildRegion       bool
 }
 
 func (s *StepRegisterAMI) Run(ctx context.Context, state multistep.StateBag) multistep.StepAction {
@@ -34,8 +36,25 @@ func (s *StepRegisterAMI) Run(ctx context.Context, state multistep.StateBag) mul
 
 	blockDevices := s.combineDevices(snapshotIds)
 
+	// Create the image
+	amiName := config.AMIName
+	state.Put("intermediary_image", false)
+	if config.AMIEncryptBootVolume.True() || s.AMISkipBuildRegion {
+		state.Put("intermediary_image", true)
+
+		// From AWS SDK docs: You can encrypt a copy of an unencrypted snapshot,
+		// but you cannot use it to create an unencrypted copy of an encrypted
+		// snapshot. Your default CMK for EBS is used unless you specify a
+		// non-default key using KmsKeyId.
+
+		// If encrypt_boot is nil or true, we need to create a temporary image
+		// so that in step_region_copy, we can copy it with the correct
+		// encryption
+		amiName = random.AlphaNum(7)
+	}
+
 	registerOpts := &ec2.RegisterImageInput{
-		Name:                &config.AMIName,
+		Name:                &amiName,
 		Architecture:        aws.String(s.Architecture),
 		RootDeviceName:      aws.String(s.RootDevice.DeviceName),
 		VirtualizationType:  aws.String(config.AMIVirtType),