| 1 | # đŸ¤– Account hardening: an all-region CloudTrail with log-file validation, |
| 2 | # writing to its own locked-down bucket (90-day retention — enough to |
| 3 | # investigate, not an unbounded cost). Management events only, which keeps |
| 4 | # the trail in the free tier. |
| 5 | |
| 6 | resource "aws_s3_bucket" "trail_logs" { |
| 7 | bucket = "eleven-cloudtrail-${local.account_id}" |
| 8 | } |
| 9 | |
| 10 | resource "aws_s3_bucket_public_access_block" "trail_logs" { |
| 11 | bucket = aws_s3_bucket.trail_logs.id |
| 12 | |
| 13 | block_public_acls = true |
| 14 | block_public_policy = true |
| 15 | ignore_public_acls = true |
| 16 | restrict_public_buckets = true |
| 17 | } |
| 18 | |
| 19 | resource "aws_s3_bucket_lifecycle_configuration" "trail_logs" { |
| 20 | bucket = aws_s3_bucket.trail_logs.id |
| 21 | |
| 22 | rule { |
| 23 | id = "expire-90d" |
| 24 | status = "Enabled" |
| 25 | |
| 26 | filter {} |
| 27 | |
| 28 | expiration { |
| 29 | days = 90 |
| 30 | } |
| 31 | } |
| 32 | } |
| 33 | |
| 34 | data "aws_iam_policy_document" "trail_logs" { |
| 35 | statement { |
| 36 | sid = "CloudTrailAclCheck" |
| 37 | actions = ["s3:GetBucketAcl"] |
| 38 | resources = [aws_s3_bucket.trail_logs.arn] |
| 39 | |
| 40 | principals { |
| 41 | type = "Service" |
| 42 | identifiers = ["cloudtrail.amazonaws.com"] |
| 43 | } |
| 44 | } |
| 45 | |
| 46 | statement { |
| 47 | sid = "CloudTrailWrite" |
| 48 | actions = ["s3:PutObject"] |
| 49 | resources = ["${aws_s3_bucket.trail_logs.arn}/AWSLogs/${local.account_id}/*"] |
| 50 | |
| 51 | principals { |
| 52 | type = "Service" |
| 53 | identifiers = ["cloudtrail.amazonaws.com"] |
| 54 | } |
| 55 | |
| 56 | condition { |
| 57 | test = "StringEquals" |
| 58 | variable = "s3:x-amz-acl" |
| 59 | values = ["bucket-owner-full-control"] |
| 60 | } |
| 61 | } |
| 62 | |
| 63 | # TLS-only: deny any request arriving over plain HTTP (CloudTrail's own |
| 64 | # delivery is HTTPS; this just makes it policy). |
| 65 | statement { |
| 66 | sid = "DenyInsecureTransport" |
| 67 | effect = "Deny" |
| 68 | actions = ["s3:*"] |
| 69 | resources = [ |
| 70 | aws_s3_bucket.trail_logs.arn, |
| 71 | "${aws_s3_bucket.trail_logs.arn}/*", |
| 72 | ] |
| 73 | |
| 74 | principals { |
| 75 | type = "*" |
| 76 | identifiers = ["*"] |
| 77 | } |
| 78 | |
| 79 | condition { |
| 80 | test = "Bool" |
| 81 | variable = "aws:SecureTransport" |
| 82 | values = ["false"] |
| 83 | } |
| 84 | } |
| 85 | } |
| 86 | |
| 87 | resource "aws_s3_bucket_policy" "trail_logs" { |
| 88 | bucket = aws_s3_bucket.trail_logs.id |
| 89 | policy = data.aws_iam_policy_document.trail_logs.json |
| 90 | } |
| 91 | |
| 92 | resource "aws_cloudtrail" "main" { |
| 93 | name = "eleven-account-trail" |
| 94 | s3_bucket_name = aws_s3_bucket.trail_logs.id |
| 95 | is_multi_region_trail = true |
| 96 | include_global_service_events = true |
| 97 | enable_log_file_validation = true |
| 98 | |
| 99 | depends_on = [aws_s3_bucket_policy.trail_logs] |
| 100 | } |
| 101 | |
amadan