plus3it · johnricords · Mar 28, 2024 · Mar 20, 2024 · Mar 27, 2024 · Mar 27, 2024
diff --git a/.github/dependabot.yml b/.github/dependabot.yml
@@ -18,3 +18,12 @@ updates:
       docker:
         patterns:
           - "*"
+  # Maintain dependencies for terraform
+  - package-ecosystem: terraform
+    directory: /
+    schedule:
+      interval: weekly
+    groups:
+      terraform:
+        patterns:
+          - "*"
diff --git a/Dockerfile b/Dockerfile
@@ -1 +1,6 @@
 FROM plus3it/tardigrade-ci:0.24.15
+
+COPY ./src/python/requirements.txt /app/requirements/lambda.txt
+
+RUN python -m pip install --no-cache-dir \
+    -r /app/requirements/lambda.txt
diff --git a/README.md b/README.md
@@ -1,3 +1,66 @@
-# terraform-aws-tardigrade-iam-key-enforcer
-Module to manage IAM key enforcer
+# Tardigrade IAM Key Enforcer
 
+This repo contains the Python-based Lambda function that will audit IAM Access keys for an account and will enforce key rotation as well as notify users.
+
+## Basic Function
+
+The Lambda function is triggered for each account by an Event notification that is configured to run on a schedule.
+The function audits each user in an account for access keys and determines how long before they expire, it will then notify users that their key expires in X days and that automatic key enforcement is forthcoming.
+
+<!-- BEGIN TFDOCS -->
+## Requirements
+
+| Name | Version |
+|------|---------|
+| <a name="requirement_terraform"></a> [terraform](#requirement\_terraform) | >= 1.1 |
+| <a name="requirement_aws"></a> [aws](#requirement\_aws) | >= 3.0 |
+
+## Providers
+
+| Name | Version |
+|------|---------|
+| <a name="provider_aws"></a> [aws](#provider\_aws) | >= 3.0 |
+
+## Resources
+
+| Name | Type |
+|------|------|
+| [aws_caller_identity.current](https://registry.terraform.io/providers/hashicorp/aws/latest/docs/data-sources/caller_identity) | data source |
+| [aws_iam_policy_document.lambda](https://registry.terraform.io/providers/hashicorp/aws/latest/docs/data-sources/iam_policy_document) | data source |
+| [aws_partition.current](https://registry.terraform.io/providers/hashicorp/aws/latest/docs/data-sources/partition) | data source |
+| [aws_region.current](https://registry.terraform.io/providers/hashicorp/aws/latest/docs/data-sources/region) | data source |
+
+## Inputs
+
+| Name | Description | Type | Default | Required |
+|------|-------------|------|---------|:--------:|
+| <a name="input_admin_email"></a> [admin\_email](#input\_admin\_email) | Admin Email that will receive all emails and reports about actions taken if email is enabled | `string` | n/a | yes |
+| <a name="input_assume_role_name"></a> [assume\_role\_name](#input\_assume\_role\_name) | Name of the IAM role that the lambda will assume in the target account | `string` | n/a | yes |
+| <a name="input_email_source"></a> [email\_source](#input\_email\_source) | Email that will be used to send messages | `string` | n/a | yes |
+| <a name="input_key_age_delete"></a> [key\_age\_delete](#input\_key\_age\_delete) | Age at which a key should be deleted (e.g. 120) | `number` | n/a | yes |
+| <a name="input_key_age_inactive"></a> [key\_age\_inactive](#input\_key\_age\_inactive) | Age at which a key should be inactive (e.g. 90) | `number` | n/a | yes |
+| <a name="input_key_age_warning"></a> [key\_age\_warning](#input\_key\_age\_warning) | Age at which to warn (e.g. 75) | `number` | n/a | yes |
+| <a name="input_key_use_threshold"></a> [key\_use\_threshold](#input\_key\_use\_threshold) | Age at which unused keys should be deleted (e.g.30) | `number` | n/a | yes |
+| <a name="input_accounts"></a> [accounts](#input\_accounts) | List of account objects to create events for | <pre>list(object({<br>    account_name        = string<br>    account_number      = string<br>    role_name           = optional(string) # deprecated<br>    armed               = bool<br>    debug               = optional(bool, false)<br>    email_user_enabled  = bool<br>    email_targets       = list(string)<br>    exempt_groups       = list(string)<br>    schedule_expression = optional(string, "cron(0 1 ? * SUN *)")<br><br>  }))</pre> | `[]` | no |
+| <a name="input_email_admin_report_enabled"></a> [email\_admin\_report\_enabled](#input\_email\_admin\_report\_enabled) | Used to enable or disable the SES emailed report | `bool` | `false` | no |
+| <a name="input_email_admin_report_subject"></a> [email\_admin\_report\_subject](#input\_email\_admin\_report\_subject) | Subject of the report email that is sent | `string` | `null` | no |
+| <a name="input_email_banner_message"></a> [email\_banner\_message](#input\_email\_banner\_message) | Messages that will be at the top of all emails sent to notify recipients of important information | `string` | `""` | no |
+| <a name="input_email_banner_message_color"></a> [email\_banner\_message\_color](#input\_email\_banner\_message\_color) | Color of email banner message, must be valid html color | `string` | `"red"` | no |
+| <a name="input_email_tag"></a> [email\_tag](#input\_email\_tag) | Tag to be placed on the IAM user that we can use to notify when their key is going to be disabled/deleted | `string` | `"keyenforcer:email"` | no |
+| <a name="input_email_templates"></a> [email\_templates](#input\_email\_templates) | Email templates to use for Admin and User emails | <pre>object({<br>    admin = optional(object({<br>      subject = optional(string, null),<br>      html    = optional(string, null),<br>      text    = optional(string, null),<br>    }), {}),<br>    user = optional(object({<br>      subject = optional(string, null),<br>      html    = optional(string, null),<br>      text    = optional(string, null),<br>    }), {})<br>  })</pre> | `{}` | no |
+| <a name="input_lambda"></a> [lambda](#input\_lambda) | Map of any additional arguments for the upstream lambda module. See <https://github.com/terraform-aws-modules/terraform-aws-lambda> | <pre>object({<br>    artifacts_dir            = optional(string, "builds")<br>    build_in_docker          = optional(bool, false)<br>    create_package           = optional(bool, true)<br>    ephemeral_storage_size   = optional(number)<br>    ignore_source_code_hash  = optional(bool, true)<br>    local_existing_package   = optional(string)<br>    recreate_missing_package = optional(bool, false)<br>    runtime                  = optional(string, "python3.11")<br>    s3_bucket                = optional(string)<br>    s3_existing_package      = optional(map(string))<br>    s3_prefix                = optional(string)<br>    store_on_s3              = optional(bool, false)<br>    timeout                  = optional(number, 300)<br>    source_path = optional(object({<br>      patterns = optional(list(string), ["!\\.terragrunt-source-manifest"])<br>    }), {})<br>  })</pre> | `{}` | no |
+| <a name="input_log_level"></a> [log\_level](#input\_log\_level) | Log level for lambda | `string` | `"INFO"` | no |
+| <a name="input_project_name"></a> [project\_name](#input\_project\_name) | Project name to prefix resources with | `string` | `"iam-key-enforcer"` | no |
+| <a name="input_s3_bucket"></a> [s3\_bucket](#input\_s3\_bucket) | Bucket name to write the audit report to if s3\_enabled is set to 'true' | `string` | `null` | no |
+| <a name="input_s3_enabled"></a> [s3\_enabled](#input\_s3\_enabled) | Set to 'true' and provide s3\_bucket if the audit report should be written to S3 | `bool` | `false` | no |
+| <a name="input_schedule_expression"></a> [schedule\_expression](#input\_schedule\_expression) | (DEPRECATED) Schedule Expressions for Rules | `string` | `null` | no |
+| <a name="input_tags"></a> [tags](#input\_tags) | Tags for resource | `map(string)` | `{}` | no |
+
+## Outputs
+
+| Name | Description |
+|------|-------------|
+| <a name="output_lambda"></a> [lambda](#output\_lambda) | The lambda module object |
+| <a name="output_queue"></a> [queue](#output\_queue) | The SQS Queue resource object |
+
+<!-- END TFDOCS -->
diff --git a/email_templates/admin_email.html b/email_templates/admin_email.html
@@ -0,0 +1,53 @@
+{{#if email_banner_msg}}
+<h1 style="color:{{email_banner_msg_color}}">{{email_banner_msg}}</h1>
+{{/if}}
+
+<h2>Expiring Access Key Report for {{account_number}} - {{account_name}}</h2>
+
+{{#if unarmed}}
+<h3 style="color:red">
+    The IAM Key Enforcer is not active and NO action has been taken on your key
+</h3>
+<p>
+    The information below is for informational purposes and represents the results if the IAM Key Enforcer were active.
+</p>
+{{/if}}
+
+<p>
+    Access Keys over {{key_age_inactive}} days old have been DEACTIVATED, keys older than {{key_age_delete}} days have
+    been DELETED.
+    Access keys over {{key_age_warning}} days old are DEACTIVATED at {{key_age_inactive}} days old and DELETED after
+    {{key_age_delete}} days old.
+    Rotate any keys as necessary to prevent disruption to your applications.
+</p>
+
+{{#if exempt_groups}}
+<p>
+    Grayed out rows are exempt via membership in an exempt IAM Group(s):{{exempt_groups}}.
+    <br />
+    Exempted group members also have a key status value of &lt;STATUS&gt; (Exempt).
+</p>
+{{/if}}
+
+<table>
+    <thead>
+        <tr>
+            <th>IAM User Name</th>
+            <th>Access Key ID</th>
+            <th>Key Age</th>
+            <th>Key Status</th>
+            <th>Last Used</th>
+        </tr>
+    </thead>
+    <tbody>
+        {{#each key_report_contents}}
+        <tr bgcolor="{{bg_color}}">
+            <td>{{user_name}}</td>
+            <td>{{access_key_id}}</td>
+            <td>{{key_age}}</td>
+            <td>{{key_status}}</td>
+            <td>{{last_used_date}}</td>
+        </tr>
+        {{/each}}
+    </tbody>
+</table>
diff --git a/email_templates/admin_email.txt b/email_templates/admin_email.txt
@@ -0,0 +1,26 @@
+{{#if email_banner_msg}}
+{{email_banner_msg}}
+{{/if}}
+
+<h2>Expiring Access Key Report for {{account_number}} - {{account_name}}</h2>
+
+{{#if unarmed}}
+    The IAM Key Enforcer is not active and NO action has been taken on your key
+
+    The information below is for informational purposes and represents the results if the IAM Key Enforcer were active.
+{{/if}}
+
+Access Keys over {{key_age_inactive}} days old have been DEACTIVATED, keys older than {{key_age_delete}} days have been DELETED.
+Access keys over {{key_age_warning}} days old are DEACTIVATED at {{key_age_inactive}} days old and DELETED after {{key_age_delete}} days old.
+Rotate any keys as necessary to prevent disruption to your applications.
+
+
+{{#if exempt_groups}}
+    Exempted IAM Group(s):{{exempt_groups}}.
+    Exempted group members have a key status value of "STATUS" (Exempt).
+{{/if}}
+
+IAM User Name, Access Key ID, Key Age, Key Status, Last Used
+{{#each key_report_contents}}
+    {{user_name}}, {{access_key_id}}, {{key_age}}, {{key_status}}, {{last_used_date}}
+{{/each}}
diff --git a/email_templates/user_email.html b/email_templates/user_email.html
@@ -0,0 +1,16 @@
+{{#if email_banner_msg}}
+<h1 style="color:{{email_banner_msg_color}}">{{email_banner_msg}}</h1>
+{{/if}}
+
+<h2>Expiring Access Key Report for {{user_name}}</h2>
+
+{{#if unarmed}}
+<h3 style="color:red">
+    The IAM Key Enforcer is not active and NO action has been taken on your key
+</h3>
+<p>
+    The information below is for informational purposes and represents the results if the IAM Key Enforcer were active.
+</p>
+{{/if}}
+
+<p>The access key {{access_key_id}} is over {{key_age}} days old and has been {{action}}.</p>
diff --git a/email_templates/user_email.txt b/email_templates/user_email.txt
@@ -0,0 +1,13 @@
+{{#if email_banner_msg}}
+{{email_banner_msg}}
+{{/if}}
+
+Expiring Access Key Report for {{user_name}}
+
+{{#if unarmed}}
+    The IAM Key Enforcer is not active and NO action has been taken on your key
+
+    The information below is for informational purposes and represents the results if the IAM Key Enforcer were active.
+{{/if}}
+
+The access key {{access_key_id}} is over {{key_age}} days old and has been {{action}}.
diff --git a/main.tf b/main.tf
@@ -0,0 +1,191 @@
+data "aws_caller_identity" "current" {}
+data "aws_partition" "current" {}
+data "aws_region" "current" {}
+
+data "aws_iam_policy_document" "lambda" {
+  statement {
+    sid = "AllowS3Object"
+    actions = [
+      "s3:PutObject",
+      "s3:PutObjectTagging",
+      "s3:PutObjectVersionTagging",
+    ]
+    resources = ["arn:${data.aws_partition.current.partition}:s3:::${var.s3_bucket}/*"]
+  }
+
+  statement {
+    actions = [
+      "ses:SendEmail",
+      "ses:SendTemplatedEmail",
+      "ses:TestRenderTemplate"
+    ]
+    resources = [
+      "*"
+    ]
+  }
+
+  statement {
+    sid = "AllowAssumeRole"
+    actions = [
+      "sts:AssumeRole"
+    ]
+    resources = [
+      "arn:${data.aws_partition.current.partition}:iam::*:role/${var.assume_role_name}"
+    ]
+  }
+}
+
+module "lambda" {
+  source = "git::https://github.com/terraform-aws-modules/terraform-aws-lambda.git?ref=v7.2.1"
+
+  description   = "Lambda function for Key Enforcement"
+  function_name = var.project_name
+  handler       = "iam_key_enforcer.lambda_handler"
+  tags          = var.tags
+
+  attach_policy_json = true
+  policy_json        = data.aws_iam_policy_document.lambda.json
+
+  artifacts_dir            = var.lambda.artifacts_dir
+  build_in_docker          = var.lambda.build_in_docker
+  create_package           = var.lambda.create_package
+  ignore_source_code_hash  = var.lambda.ignore_source_code_hash
+  local_existing_package   = var.lambda.local_existing_package
+  recreate_missing_package = var.lambda.recreate_missing_package
+  ephemeral_storage_size   = var.lambda.ephemeral_storage_size
+  runtime                  = var.lambda.runtime
+  s3_bucket                = var.lambda.s3_bucket
+  s3_existing_package      = var.lambda.s3_existing_package
+  s3_prefix                = var.lambda.s3_prefix
+  store_on_s3              = var.lambda.store_on_s3
+  timeout                  = var.lambda.timeout
+
+  environment_variables = {
+    LOG_LEVEL                  = var.log_level
+    EMAIL_ADMIN_REPORT_ENABLED = var.email_admin_report_enabled
+    EMAIL_ADMIN_REPORT_SUBJECT = var.email_admin_report_subject
+    EMAIL_SOURCE               = var.email_source
+    ADMIN_EMAIL                = var.admin_email
+    KEY_AGE_WARNING            = var.key_age_warning
+    KEY_AGE_INACTIVE           = var.key_age_inactive
+    KEY_AGE_DELETE             = var.key_age_delete
+    KEY_USE_THRESHOLD          = var.key_use_threshold
+    S3_ENABLED                 = var.s3_enabled
+    S3_BUCKET                  = var.s3_bucket
+    EMAIL_TAG                  = var.email_tag
+    EMAIL_BANNER_MSG           = var.email_banner_message
+    EMAIL_BANNER_MSG_COLOR     = var.email_banner_message_color
+    EMAIL_USER_TEMPLATE        = aws_ses_template.user_template.id
+    EMAIL_ADMIN_TEMPLATE       = aws_ses_template.admin_template.id
+  }
+
+  source_path = [
+    {
+      path             = "${path.module}/src/python",
+      prefix_in_zip    = ""
+      pip_requirements = true
+      patterns         = var.lambda.source_path.patterns
+    },
+  ]
+}
+
+resource "aws_lambda_permission" "this" {
+  action        = "lambda:InvokeFunction"
+  function_name = module.lambda.lambda_function_name
+  principal     = "events.amazonaws.com"
+  source_arn    = "arn:${data.aws_partition.current.partition}:events:${data.aws_region.current.name}:${data.aws_caller_identity.current.account_id}:rule/${var.project_name}-*"
+}
+
+##############################
+# SQS Queue Policy
+##############################
+resource "aws_sqs_queue_policy" "this" {
+  queue_url = aws_sqs_queue.this.id
+  policy = jsonencode(
+    {
+      Version = "2012-10-17",
+      Id      = "sqspolicy",
+      Statement : [
+        {
+          Sid       = "AllowSend",
+          Effect    = "Allow",
+          Principal = "*",
+          Action    = "sqs:SendMessage",
+          Resource  = aws_sqs_queue.this.arn,
+          Condition = {
+            "ArnLike" : {
+              "aws:SourceArn" : "arn:${data.aws_partition.current.partition}:events:*:*:rule/${var.project_name}-*"
+            }
+          }
+        },
+        {
+          Sid    = "AllowRead",
+          Effect = "Allow",
+          "Principal" : {
+            "AWS" : "arn:${data.aws_partition.current.partition}:iam::${data.aws_caller_identity.current.account_id}:root"
+          },
+          Action   = "sqs:ReceiveMessage",
+          Resource = aws_sqs_queue.this.arn,
+        }
+      ]
+    }
+  )
+}
+
+##############################
+# SQS Queue
+##############################
+resource "aws_sqs_queue" "this" {
+  name                       = "${var.project_name}-dlq"
+  message_retention_seconds  = 1209600
+  receive_wait_time_seconds  = 20
+  visibility_timeout_seconds = 30
+  tags                       = var.tags
+}
+
+##############################
+# Schedule Event
+##############################
+module "scheduled_events" {
+  source   = "./modules/scheduled_event"
+  for_each = { for account in var.accounts : account.account_name => account }
+
+  event_name             = each.value.account_name
+  event_rule_description = "Scheduled Event that runs IAM Key Enforcer Lambda for account ${each.value.account_number} - ${each.value.account_name}"
+  lambda_arn             = module.lambda.lambda_function_arn
+  project_name           = var.project_name
+  tags                   = var.tags
+  schedule_expression    = var.schedule_expression != null ? var.schedule_expression : each.value.schedule_expression
+
+
+  dead_letter_config = {
+    arn = aws_sqs_queue.this.arn
+  }
+
+  input_transformer = {
+    input_template = jsonencode({
+      "account_number" : each.value.account_number,
+      "account_name" : each.value.account_name,
+      "role_arn" : "arn:${data.aws_partition.current.partition}:iam::${each.value.account_number}:role/${var.assume_role_name}",
+      "armed" : each.value.armed,
+      "debug" : each.value.debug,
+      "email_targets" : each.value.email_targets,
+      "exempt_groups" : each.value.exempt_groups,
+      "email_user_enabled" : each.value.email_user_enabled,
+    })
+  }
+}
+
+resource "aws_ses_template" "user_template" {
+  name    = "${var.project_name}-user"
+  html    = var.email_templates.user.html != null ? var.email_templates.user.html : file("${path.module}/email_templates/user_email.html")
+  subject = var.email_templates.user.subject != null ? var.email_templates.user.subject : "IAM User Key {{armed_state_msg}} for {{user_name}}"
+  text    = var.email_templates.user.text != null ? var.email_templates.user.text : file("${path.module}/email_templates/user_email.txt")
+}
+
+resource "aws_ses_template" "admin_template" {
+  name    = "${var.project_name}-admin"
+  html    = var.email_templates.admin.html != null ? var.email_templates.admin.html : file("${path.module}/email_templates/admin_email.html")
+  subject = var.email_templates.admin.subject != null ? var.email_templates.admin.subject : "IAM Key Enforcement Report for {{account_number}}"
+  text    = var.email_templates.admin.text != null ? var.email_templates.admin.text : file("${path.module}/email_templates/admin_email.txt")
+}