How SigV4 Works — Envoy Signs AWS Requests on Your Behalf

How SigV4 Works — Envoy Signs AWS Requests on Your Behalf A sequence diagram generated by Archify. HTTP request Add Authorization header · AWS4-HMAC-SHA256 Load credentials → derive Signing Key → compute Signature, attach to header Response AWS verifies the signature, then responds Response Inside Envoy: load AWS Credentials → generate SigV4 signature (HMAC-SHA256) Inside AWS: verify signature → respond Client · calling application · Sequence participant Client calling application Envoy Proxy · istio-proxy · aws_request_signing · Sequence participant Envoy Proxy istio-proxy · aws_request_signing AWS Service · e.g. S3, DynamoDB · Sequence participant AWS Service e.g. S3, DynamoDB Legend return security default message