Initial script dump, WIP

2 files changed, 91 insertions, 0 deletions

diff --git a/README.md b/README.md
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+# route53-ddns
+
+A simple (b)ash script aimed for usage on LEDE/OpenWRT devices which enables sending DDNS updates to Route53
+
+## Requirements
+
+ - [curl](https://lede-project.org/packages/pkgdata/curl)
+ - [openssl-util](https://lede-project.org/packages/pkgdata/openssl-util)
+
+## Usage
+
+```bash
+$ TBD
+```
diff --git a/route53.sh b/route53.sh
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+#!/bin/bash
+
+### route53.sh
+### For use in LEDE / OpenWRT DDNS scenarios
+###
+### Requires: curl, openssl-util
+
+set -euo pipefail
+IFS=$'\n\t'
+
+ENDPOINT="route53.amazonaws.com"
+RECORD_TTL=300
+RECORD_NAME=""
+RECORD_TYPE="A"
+RECORD_VALUE="1.2.3.4"
+HOSTED_ZONE_ID=""
+PATH="/2013-04-01/hostedzone/${HOSTED_ZONE_ID}/rrset/"
+
+AWS_ACCESS_KEY_ID=''
+AWS_SECRET_ACCESS_KEY=''
+AWS_REGION='us-east-1'
+AWS_SERVICE='route53domains'
+
+date=`date +%Y%m%d`
+
+request_body=$(cat <<EOF
+<?xml version="1.0" encoding="UTF-8"?>
+<ChangeResourceRecordSetsRequest xmlns="https://route53.amazonaws.com/doc/2013-04-01/">
+<ChangeBatch>
+   <Changes>
+      <Change>
+         <Action>UPSERT</Action>
+         <ResourceRecordSet>
+            <Name>${RECORD_NAME}</Name>
+            <Type>${RECORD_TYPE}</Type>
+            <TTL>${RECORD_TTL}</TTL>
+            <ResourceRecords>
+               <ResourceRecord>
+                  <Value>${RECORD_VALUE}</Value>
+               </ResourceRecord>
+            </ResourceRecords>
+         </ResourceRecordSet>
+      </Change>
+   </Changes>
+</ChangeBatch>
+</ChangeResourceRecordSetsRequest>
+EOF
+)
+
+canonical_request="POST\n${PATH}\n\nhost:route53.amazon.com\nx-amz-date:`date -Iseconds`\n\nhost;x-amz-date"
+
+sign() {
+    key=$1
+    msg=$2
+    echo -n $msg | openssl dgst -sha256 -hmac $key | sed 's/^.* //'
+}
+
+getSignatureKey() {
+    # usage: getSignatureKey date region service
+    date_key=$(sign AWS4${AWS_SECRET_ACCESS_KEY_ID} ${date})
+    region_key=$(sign $date_key $AWS_REGION)
+    service_key=$(sign $region_key $AWS_SERVICE)
+    signing_key=$(sign $service_key aws4_request)
+    echo -n $signing_key
+}
+
+amzdate=`date -Iseconds`
+
+credential="${AWS_ACCESS_KEY_ID}/${date}/${AWS_REGION}/${AWS_SERVICE}/aws4_request"
+signed_headers="host;x-amz-date"
+signature=""
+authorization="AWS4-HMAC-SHA256 Credential=${credential},SignedHeaders=${signed_headers},Signature=${signature}"
+
+curl \
+    -H "x-amz-date=`date -Iseconds`" \
+    -H "Authorization=${authorization}}"
+    "https://${ENDPOINT}"