SES: Email template unicode support is broken

[dkuzmenko-dsr]

Describe the bug

I run into the issue on using CDK import of aws_ses.CfnTemplate resource. Imported email templates into a CDK stack I've started to get errors on each following cdk import run reporting that email templates has been modified and cdk cannot do import on modified stacks.

Meanwhile not CDK diff nor drift detection report any difference.

I've tried to perform a modification in a template and got that little modification will rewrite all the fields in the template. Also server side template is looking like all unicode characters was replaced with question marks (?).

Removing all unicode symbols from email template fixes the issue.

Regression Issue

• Select this option if this issue appears to be a regression.

Last Known Working CDK Version

No response

Expected Behavior

Resources
[~] AWS::SES::Template SesEmailTemplates/UnicodeTestTemplate SesEmailTemplatesUnicodeTestTemplateB22B733D may be replaced
 └─ [~] Template (may cause replacement)
     └─ [~] .SubjectPart:
         ├─ [-] Unicode ® char.
         └─ [+] Unicode ® char

Current Behavior

Resources
[~] AWS::SES::Template SesEmailTemplates/UnicodeTestTemplate SesEmailTemplatesUnicodeTestTemplateB22B733D may be replaced
 └─ [~] Template (may cause replacement)
     ├─ [~] .HtmlPart:
     │   ├─ [-] Unicode ? char.
     │   └─ [+] Unicode ® char.
     ├─ [~] .SubjectPart:
     │   ├─ [-] Unicode ? char.
     │   └─ [+] Unicode ® char.
     └─ [~] .TextPart:
         ├─ [-] Unicode ? char.
         └─ [+] Unicode ® char

Reproduction Steps

1. Deploy this construct in a stack.

    new ses.CfnTemplate(
      this,
      "UnicodeTestTemplate",
      {

        template: {
          templateName: "UnicodeTestTemplate",
          subjectPart: "Unicode ® char.",
          textPart: "Unicode ® char.",
          htmlPart: "Unicode ® char.",

        },
      }
    );

The result is good and diff is empty after deploy.

2. Update one field in the template, like remove point from subjectPart.
3. Run cdk diff (I've also tried cdk diff --strict, result is the same) and look at the result.

Possible Solution

No response

Additional Information/Context

No response

CDK CLI Version

2.177.0

Framework Version

No response

Node.js Version

22.13.1

OS

Arch Linux

Language

TypeScript

Language Version

5.6.3

Other information

No response

[ashishdhingra]

Reproducible locally where cdk diff displays the below output after following reproduction steps:

Resources
[~] AWS::SES::Template UnicodeTestTemplate UnicodeTestTemplate may be replaced
 └─ [~] Template (may cause replacement)
     ├─ [~] .HtmlPart:
     │   ├─ [-] Unicode ? char.
     │   └─ [+] Unicode ® char.
     ├─ [~] .SubjectPart:
     │   ├─ [-] Unicode ? char.
     │   └─ [+] Unicode ® char
     └─ [~] .TextPart:
         ├─ [-] Unicode ? char.
         └─ [+] Unicode ® char.


✨  Number of stacks with differences: 1

Manually updating the template in AWS CloudFormation console (upload from cdk.out directory) and viewing Changeset displays the following differences:

Notice that in CloudFormation, it displays ? character for ® character.

Using AWS CLI:

• Command aws cloudformation list-change-sets --stack-name CdktestStack displays the below output:

    {
      "Summaries": [
          {
              "StackId": "arn:aws:cloudformation:us-east-2:<<ACCOUNT-ID>>:stack/CdktestStack/5a8234c0-e331-11ef-a3d3-0af098d028b9",
              "StackName": "CdktestStack",
              "ChangeSetId": "arn:aws:cloudformation:us-east-2:<<ACCOUNT-ID>>:changeSet/CdktestSta-tajqkgrkem-sfyju1c13m/3c63df56-1890-4cf5-a69c-d029c2993d33",
              "ChangeSetName": "CdktestSta-tajqkgrkem-sfyju1c13m",
              "ExecutionStatus": "AVAILABLE",
              "Status": "CREATE_COMPLETE",
              "CreationTime": "2025-02-04T19:55:10.873000+00:00",
              "IncludeNestedStacks": false
          }
      ]
  }

• Command aws cloudformation describe-change-set --change-set-name arn:aws:cloudformation:us-east-2:<<ACCOUNT-ID>>:changeSet/CdktestSta-tajqkgrkem-sfyju1c13m/3c63df56-1890-4cf5-a69c-d029c2993d33 --include-property-values displays the below output:

  {
      "Changes": [
          {
              "Type": "Resource",
              "ResourceChange": {
                  "Action": "Modify",
                  "LogicalResourceId": "UnicodeTestTemplate",
                  "PhysicalResourceId": "UnicodeTestTemplate",
                  "ResourceType": "AWS::SES::Template",
                  "Replacement": "False",
                  "Scope": [
                      "Properties"
                  ],
                  "Details": [
                      {
                          "Target": {
                              "Attribute": "Properties",
                              "Name": "Template",
                              "RequiresRecreation": "Never",
                              "Path": "/Properties/Template/SubjectPart",
                              "BeforeValue": "Unicode ? char.",
                              "AfterValue": "Unicode ? char",
                              "AttributeChangeType": "Modify"
                          },
                          "Evaluation": "Static",
                          "ChangeSource": "DirectModification"
                      }
                  ],
                "BeforeContext": "{\"Properties\":{\"Template\":{\"HtmlPart\":\"Unicode ? char.\",\"TextPart\":\"Unicode ? char.\",\"TemplateName\":\"UnicodeTestTemplate\",\"SubjectPart\":\"Unicode ? char.\"}},\"Metadata\":{\"aws:cdk:path\":\"CdktestStack/UnicodeTestTemplate\"}}",
                "AfterContext": "{\"Properties\":{\"Template\":{\"HtmlPart\":\"Unicode ? char.\",\"TextPart\":\"Unicode ? char.\",\"TemplateName\":\"UnicodeTestTemplate\",\"SubjectPart\":\"Unicode ? char\"}},\"Metadata\":{\"aws:cdk:path\":\"CdktestStack/UnicodeTestTemplate\"}}"
              }
          }
      ],
      "ChangeSetName": "CdktestSta-tajqkgrkem-sfyju1c13m",
      "ChangeSetId": "arn:aws:cloudformation:us-east-2:<<ACCOUNT-ID>>:changeSet/CdktestSta-tajqkgrkem-sfyju1c13m/3c63df56-1890-4cf5-a69c-d029c2993d33",
      "StackId": "arn:aws:cloudformation:us-east-2:<<ACCOUNT-ID>>:stack/CdktestStack/5a8234c0-e331-11ef-a3d3-0af098d028b9",
      "StackName": "CdktestStack",
      "Description": null,
      "Parameters": [
          {
              "ParameterKey": "BootstrapVersion",
              "ParameterValue": "/cdk-bootstrap/hnb659fds/version",
              "ResolvedValue": "25"
          }
      ],
      "CreationTime": "2025-02-04T19:55:10.873000+00:00",
      "ExecutionStatus": "AVAILABLE",
      "Status": "CREATE_COMPLETE",
      "StatusReason": null,
      "NotificationARNs": [],
      "RollbackConfiguration": {
          "RollbackTriggers": []
      },
      "Capabilities": [],
      "Tags": null,
      "ParentChangeSetId": null,
      "IncludeNestedStacks": false,
      "RootChangeSetId": null,
      "OnStackFailure": null,
      "ImportExistingResources": null
  }

If we examine the template in AWS CloudFormation console, below are the contents:

{
  "Resources": {
    "UnicodeTestTemplate": {
      "Type": "AWS::SES::Template",
      "Properties": {
        "Template": {
          "HtmlPart": "Unicode ? char.",
          "SubjectPart": "Unicode ? char",
          "TemplateName": "UnicodeTestTemplate",
          "TextPart": "Unicode ? char."
        }
      },
      "Metadata": {
        "aws:cdk:path": "CdktestStack/UnicodeTestTemplate"
      }
    },
    "CDKMetadata": {
      "Type": "AWS::CDK::Metadata",
      "Properties": {
        "Analytics": "v2:deflate64:H4sIAAAAAAAA/yXFSw5AMBAA0LN03w4VSe3dAHupGknpRzqlC3F3C2/zGpBKQc10IWHWQzi7wDNmbQ6uC82EBP0WJvSn0xl5v4UBKV7J4MtDXBF2qm7ZQVNDy3ayVqQrZOsRhv8PvGWMX2EAAAA="
      },
      "Metadata": {
        "aws:cdk:path": "CdktestStack/CDKMetadata/Default"
      }
    }
  },
  "Parameters": {
    "BootstrapVersion": {
      "Type": "AWS::SSM::Parameter::Value<String>",
      "Default": "/cdk-bootstrap/hnb659fds/version",
      "Description": "Version of the CDK Bootstrap resources in this environment, automatically retrieved from SSM Parameter Store. [cdk:skip]"
    }
  },
  "Rules": {
    "CheckBootstrapVersion": {
      "Assertions": [
        {
          "Assert": {
            "Fn::Not": [
              {
                "Fn::Contains": [
                  [
                    "1",
                    "2",
                    "3",
                    "4",
                    "5"
                  ],
                  {
                    "Ref": "BootstrapVersion"
                  }
                ]
              }
            ]
          },
          "AssertDescription": "CDK bootstrap stack version 6 required. Please run 'cdk bootstrap' with a recent version of the CDK CLI."
        }
      ]
    }
  }
}

Examining SES template
Using AWS CLI,

• Command aws sesv2 list-email-templates gives below output:

  {
      "TemplatesMetadata": [
          {
              "TemplateName": "UnicodeTestTemplate",
              "CreatedTimestamp": "2025-02-04T11:51:07.088000-08:00"
          }
      ]
  }

• Command aws sesv2 get-email-template --template-name UnicodeTestTemplate gives below output:

  {
      "TemplateName": "UnicodeTestTemplate",
      "TemplateContent": {
          "Subject": "Unicode ® char.",
          "Text": "Unicode ® char.",
          "Html": "Unicode ® char."
      }
  }

So looks like correct SES email template is being deployed via CDK/CloudFormation, but CloudFormation is not displaying or returning Unicode characters properly.

Unsure how CDK could handle this scenario when CloudFormation API is not handling properly.

[kaizencc]

I can reproduce the same as @ashishdhingra. Can confirm that CDK synthesizes the correct template with ® and it is uploaded to s3 correctly. Beyond that, it's CloudFormation that takes the template from s3 as input, and it must not be converting unicode characters correctly. I will open up an internal ticket with them