transport.go

// BSD 3-Clause License

// Copyright (c) 2021, James Bowes
// Copyright (c) 2023, Alexander Taraymovich, OffBlocks
// All rights reserved.

// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are met:

// 1. Redistributions of source code must retain the above copyright notice, this
//    list of conditions and the following disclaimer.

// 2. Redistributions in binary form must reproduce the above copyright notice,
//    this list of conditions and the following disclaimer in the documentation
//    and/or other materials provided with the distribution.

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//    contributors may be used to endorse or promote products derived from
//    this software without specific prior written permission.

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package httpsig

import "net/http"

// NewSignTransport returns a new client transport that wraps the provided transport with
// http message signing and body digest creation.
//
// Use the various `WithSign*` option funcs to configure signature algorithms with their provided
// key ids. You must provide at least one signing option. A signature for every provided key id is
// included on each request. Multiple included signatures allow you to gracefully introduce stronger
// algorithms, rotate keys, etc.
func NewSignTransport(transport http.RoundTripper, opts ...signOption) http.RoundTripper {
	s := NewSigner(opts...)

	return rt(func(r *http.Request) (*http.Response, error) {
		hdr, err := s.Sign(MessageFromRequest(r))
		if err != nil {
			return nil, err
		}
		r.Header = hdr
		return transport.RoundTrip(r)
	})
}

type rt func(*http.Request) (*http.Response, error)

func (r rt) RoundTrip(req *http.Request) (*http.Response, error) { return r(req) }