AWS SigV4 Proxy

The AWS SigV4 Proxy will sign incoming HTTP requests and forward them to the host specified in the Host header.

You can strip out arbirtary headers from the incoming request by using the -s option.

Getting Started

Build and run the Proxy

The proxy uses the default AWS SDK for Go credential search path:

* Environment variables.
* Shared credentials file.
* IAM role for Amazon EC2 or ECS task role

More information can be found in the [developer guide](https://docs.aws.amazon.com/sdk-for-go/v1/developer-guide/configuring-sdk.html)

docker build -t aws-sigv4-proxy .

# Env vars
docker run --rm -ti \
  -e 'AWS_ACCESS_KEY_ID=<YOUR ACCESS KEY ID>' \
  -e 'AWS_SECRET_ACCESS_KEY=<YOUR SECRET ACCESS KEY>' \
  -p 8080:8080 \
  aws-sigv4-proxy -v

# Shared Credentials
docker run --rm -ti \
  -v ~/.aws:/root/.aws \
  -p 8080:8080 \
  -e 'AWS_SDK_LOAD_CONFIG=true' \
  -e 'AWS_PROFILE=<SOME PROFILE>' \
  aws-sigv4-proxy -v

Configuration

When running the Proxy, the following flags can be used (none are required) : s", "

Flag (or short form)	Type	Description	Default
`verbose` or `v`	Boolean	Enable additional logging, implies all the log-* options	`False`
`log-failed-requests`	Boolean	Log 4xx and 5xx response body	`False`
`log-signing-process`	Boolean	Log sigv4 signing process	`False`
`unsigned-payload`	Boolean	Prevent signing of the payload"	`False`
`port`	String	Port to serve http on	`8080`
`strip` or `s`	String	Headers to strip from incoming request	None
`custom-headers`	String	Comma-separated list of custom headers in key=value format	None
`duplicate-headers`	String	Duplicate headers to an X-Original- prefix name	None
`role-arn`	String	Amazon Resource Name (ARN) of the role to assume	None
`name`	String	AWS Service to sign for	None
`sign-host`	String	Host to sign for	None
`host`	String	Host to proxy to	None
`region`	String	AWS region to sign for	None
`upstream-url-scheme`	String	Protocol to proxy with	https
`no-verify-ssl`	Boolean	Disable peer SSL certificate validation	`False`
`transport.idle-conn-timeout`	Duration	Idle timeout to the upstream service	`40s`

Examples

# us-east-1
curl -s -H 'host: s3.amazonaws.com' http://localhost:8080/<BUCKET_NAME>

# other region
curl -s -H 'host: s3.<BUCKET_REGION>.amazonaws.com' http://localhost:8080/<BUCKET_NAME>

SQS

curl -s -H 'host: sqs.<AWS_REGION>.amazonaws.com' 'http://localhost:8080/<AWS_ACCOUNT_ID>/<QUEUE_NAME>?Action=SendMessage&MessageBody=example'

API Gateway

curl -H 'host: <REST_API_ID>.execute-api.<AWS_REGION>.amazonaws.com' http://localhost:8080/<STAGE>/<PATH>

Running the service and stripping out sigv2 authorization headers

docker run --rm -ti \
  -v ~/.aws:/root/.aws \
  -p 8080:8080 \
  -e 'AWS_SDK_LOAD_CONFIG=true' \
  -e 'AWS_PROFILE=<SOME PROFILE>' \
  aws-sigv4-proxy -v -s Authorization

Running the service and preserving the original Authorization header as X-Original-Authorization (useful because Authorization header will be overwritten.)

docker run --rm -ti \
  -v ~/.aws:/root/.aws \
  -p 8080:8080 \
  -e 'AWS_SDK_LOAD_CONFIG=true' \
  -e 'AWS_PROFILE=<SOME PROFILE>' \
  aws-sigv4-proxy -v --duplicate-headers Authorization

Running the service with Assume Role to use temporary credentials

docker run --rm -ti \
  -v ~/.aws:/root/.aws \
  -p 8080:8080 \
  -e 'AWS_SDK_LOAD_CONFIG=true' \
  -e 'AWS_PROFILE=<SOME PROFILE>' \
  aws-sigv4-proxy -v --role-arn <ARN OF ROLE TO ASSUME>

Include service name & region overrides when you notice errors like unable to determine service from host for API gateway, for example.

docker run --rm -ti \
  -v ~/.aws:/root/.aws \
  -p 8080:8080 \
  -e 'AWS_SDK_LOAD_CONFIG=true' \
  -e 'AWS_PROFILE=<SOME PROFILE>' \
  aws-sigv4-proxy -v --name execute-api --region us-east-1

OpenSearch

Access AWS OpenSearch domain, hosted in private subnet of AWS VPC, with access policy restricted to IAM role.

Prepare connection (assume role, export AWS_PROFILE, run ssh tunnel):

aws sts assume-role \
 --role-arn "arn:aws:iam::123456789012:role/example-role" \
 --role-session-name role-profile
export AWS_PROFILE=role-profile

ssh \
 -4 \
 -o BatchMode="yes" \
 -o StrictHostKeyChecking="no" \
 -o ProxyCommand="aws ssm start-session --target %h --region eu-west-1 --document-name AWS-StartSSHSession --parameters portNumber=%p" \
 -i /Users/user/.ssh/id_rsa ubuntu@i-bastion-host \
 -L 4443:vpc-private-domain-name.eu-west-1.es.amazonaws.com:443 \
 -N

Finally, run proxy:

docker run --rm -ti \
     -v ~/.aws:/root/.aws \
     --network=bridge \
     -p 8080:8080 \
     -e "AWS_SDK_LOAD_CONFIG=true" \
     -e "AWS_PROFILE=role-profile" \
     aws-sigv4-proxy \
             --verbose --log-failed-requests --log-signing-process --no-verify-ssl \
             --name es --region eu-west-1 \
             --host host.docker.internal:4443 \
             --sign-host eu-west-1.es.amazonaws.com

Access dashboard via http://localhost:8080/_dashboards/app/home#/tutorial_directory

Reference

AWS SigV4 Signing Docs
AWS SigV4 Admission Controller - Used to install the AWS SigV4 Proxy as a sidecar

License