use default key or pass in key arn

s3-logs/README.md

@@ -174,6 +174,7 @@ No modules.
 | <a name="input_bucket_name"></a> [bucket\_name](#input\_bucket\_name) | Logs S3 bucket name | `string` | `""` | no |
 | <a name="input_bucket_name_prefix"></a> [bucket\_name\_prefix](#input\_bucket\_name\_prefix) | Logs S3 bucket prefix, prepended to the AWS account ID to make the bucket name. | `string` | `"inf-logs"` | no |
 | <a name="input_component_tags"></a> [component\_tags](#input\_component\_tags) | Additional tags for Components (s3, kms, ddb) | `map(map(string))` | <pre>{<br/>  "ddb": {},<br/>  "kms": {},<br/>  "s3": {}<br/>}</pre> | no |
+| <a name="input_kms_key_arn"></a> [kms\_key\_arn](#input\_kms\_key\_arn) | AWS KMS ARN to be used for encrypting the S3 bucket.  If not provided, the default aws/s3 key will be used | `string` | `null` | no |
 | <a name="input_override_prefixes"></a> [override\_prefixes](#input\_override\_prefixes) | Override built-in prefixes by component (efs, s3, ebs, kms, role, policy, security-group). This should be used primarily for common infrastructure things | `map(string)` | `{}` | no |
 | <a name="input_tags"></a> [tags](#input\_tags) | AWS Tags to apply to appropriate resources (S3, KMS).  Do not include safeguard tags here, use the data\_safeguard field for such things. | `map(string)` | `{}` | no |
 | <a name="input_versioning_configuration"></a> [versioning\_configuration](#input\_versioning\_configuration) | S3 Versioning Configuration (Enabled, Disabled, Suspended).  To disable, use Suspended if existing bucket and Disabled if new | `string` | `"Disabled"` | no |

s3-logs/kms.tf.off

@@ -17,3 +17,140 @@ resource "aws_kms_alias" "key" {
   name          = "alias/${local.kms_key_name}"
   target_key_id = aws_kms_key.key.key_id
 }
+
+locals {
+  # basic details about the env
+  account_id          = var.account_id != "" ? var.account_id : data.aws_caller_identity.current.account_id
+  region              = data.aws_region.current.name
+  account_environment = data.aws_arn.current.partition == "aws-us-gov" ? "gov" : "ew"
+  partition           = data.aws_arn.current.partition
+
+  name           = var.name == null ? format("%v-%v", lookup(local._defaults["cloudtrail"], "name"), local.region) : var.name
+  kms_key_name   = format("%v%v", local._prefixes["kms"], local.name)
+  kms_admin_root = format("arn:%v:iam::%v:root", local.partition, local.account_id)
+  #  kms_admin_roles     = compact(concat([local.kms_admin_root], var.kms_admin_roles))
+  kms_admin_roles     = var.kms_admin_roles
+  kms_policy_document = var.kms_policy_document != null ? var.kms_policy_document : data.aws_iam_policy_document.empty.json
+}
+
+data "aws_iam_policy_document" "key_policy_combined" {
+  source_policy_documents = [
+    data.aws_iam_policy_document.key.json,
+    data.aws_iam_policy_document.key_admin.json,
+    local.kms_policy_document
+  ]
+}
+
+data "aws_iam_policy_document" "key_admin" {
+  dynamic "statement" {
+    for_each = length(local.kms_admin_roles) > 0 ? [1] : []
+    content {
+      sid       = "BuiltinKMSAdminRoles"
+      effect    = "Allow"
+      actions   = ["kms:*"]
+      resources = ["*"]
+      principals {
+        type        = "AWS"
+        identifiers = local.kms_admin_roles
+      }
+    }
+  }
+}
+
+data "aws_iam_policy_document" "empty" {}
+
+
+#---
+# key policy for clodutrail
+# https://docs.aws.amazon.com/awscloudtrail/latest/userguide/create-kms-key-policy-for-cloudtrail.html
+# can't use aws_cloudtrail.this.arn as it makes for a circular reference
+#
+# from aws-setup-s3-object-logging
+#---
+data "aws_iam_policy_document" "key" {
+  policy_id = "object-logging-cloud-trail"
+  # manage key by root and other principals
+  statement {
+    sid       = "IAMPermissionsAccessKMSManagement"
+    effect    = "Allow"
+    actions   = ["kms:*"]
+    resources = ["*"]
+    principals {
+      type        = "AWS"
+      identifiers = [local.kms_admin_root]
+    }
+  }
+  # let cloudtrial, logs, sns, and sqs find key
+  statement {
+    sid       = "KMSDescribeKeyFromServices"
+    effect    = "Allow"
+    actions   = ["kms:DescribeKey"]
+    resources = ["*"]
+    principals {
+      type        = "Service"
+      identifiers = ["cloudtrail.amazonaws.com", "sns.amazonaws.com", "sqs.amazonaws.com", "s3.amazonaws.com"]
+    }
+  }
+  statement {
+    sid    = "CloudTrailKMSEncryptAccess"
+    effect = "Allow"
+    actions = [
+      "kms:Decrypt*",
+      "kms:Encrypt*",
+      "kms:ReEncrypt*",
+      "kms:GenerateDataKey",
+    ]
+    resources = ["*"]
+    principals {
+      type        = "Service"
+      identifiers = ["cloudtrail.amazonaws.com", "s3.amazonaws.com"]
+    }
+    #    condition {
+    #      test     = "StringLike"
+    #      variable = "kms:EncryptionContext:aws:cloudtrail:arn"
+    #      values   = [format("arn:%v:cloudtrail:*:%v:trail/*", local.partition, local.account_id)]
+    #    }
+  }
+  # https://docs.aws.amazon.com/AmazonCloudWatch/latest/logs/encrypt-log-data-kms.html
+  statement {
+    sid    = "Cloudwatch"
+    effect = "Allow"
+    actions = [
+      "kms:Decrypt*",
+      "kms:Encrypt*",
+      "kms:ReEncrypt*",
+      "kms:GenerateDataKey*",
+      "kms:Describe*"
+    ]
+    resources = ["*"]
+    principals {
+      type        = "Service"
+      identifiers = ["logs.amazonaws.com", "logs.${local.region}.amazonaws.com"]
+    }
+    condition {
+      test     = "StringLike"
+      variable = "kms:EncryptionContext:aws:logs:arn"
+      values   = [format("arn:%v:logs:%v:%v:log-group:*", local.partition, local.region, local.account_id)]
+    }
+  }
+  # https://aws.amazon.com/blogs/compute/encrypting-messages-published-to-amazon-sns-with-aws-kms/
+  # https://docs.aws.amazon.com/sns/latest/dg/sns-key-management.html#sns-what-permissions-for-sse
+  # https://docs.aws.amazon.com/sns/latest/dg/sns-enable-encryption-for-topic-sqs-queue-subscriptions.html
+  statement {
+    sid    = "ServiceMSAccess"
+    effect = "Allow"
+    actions = [
+      "kms:Decrypt*",
+      "kms:GenerateDataKey*",
+      "kms:Describe*"
+    ]
+    resources = ["*"]
+    principals {
+      type        = "Service"
+      identifiers = ["sns.amazonaws.com", "sqs.amazonaws.com", "s3.amazonaws.com"]
+    }
+  }
+}
+
+# producers and consumers
+#  https://docs.aws.amazon.com/AWSSimpleQueueService/latest/SQSDeveloperGuide/sqs-key-management.html#compatibility-with-aws-services

s3-logs/main.tf

@@ -132,8 +132,8 @@ resource "aws_s3_bucket_server_side_encryption_configuration" "logs" {
   bucket = aws_s3_bucket.logs.id
   rule {
     apply_server_side_encryption_by_default {
-      #      sse_algorithm = "aws:kms"
-      sse_algorithm = "AES256"
+      sse_algorithm     = "aws:kms"
+      kms_master_key_id = var.kms_key_arn
     }
     bucket_key_enabled = true
   }

s3-logs/variables.tf

@@ -21,3 +21,9 @@ variable "versioning_configuration" {
   type        = string
   default     = "Disabled"
 }
+
+variable "kms_key_arn" {
+  description = "AWS KMS ARN to be used for encrypting the S3 bucket.  If not provided, the default aws/s3 key will be used"
+  type        = string
+  default     = null
+}