gotosocial/vendor/golang.org/x/crypto/hkdf/hkdf.go
Vyr Cossont 5b765d734e
[feature] Push notifications (#3587)
* Update push subscription API model to be Mastodon 4.0 compatible

* Add webpush-go dependency

# Conflicts:
#	go.sum

* Single-row table for storing instance's VAPID key pair

* Generate VAPID key pair during startup

* Add VAPID public key to instance info API

* Return VAPID public key when registering an app

* Store Web Push subscriptions in DB

* Add Web Push sender (similar to email sender)

* Add no-op push senders to most processor tests

* Test Web Push notifications from workers

* Delete Web Push subscriptions when account is deleted

* Implement push subscription API

* Linter fixes

* Update Swagger

* Fix enum to int migration

* Fix GetVAPIDKeyPair

* Create web push subscriptions table with indexes

* Log Web Push server error messages

* Send instance URL as Web Push JWT subject

* Accept any 2xx code as a success

* Fix malformed VAPID sub claim

* Use packed notification flags

* Remove unused date columns

* Add notification type for update notifications

Not used yet

* Make GetVAPIDKeyPair idempotent

and remove PutVAPIDKeyPair

* Post-rebase fixes

* go mod tidy

* Special-case 400 errors other than 408/429

Most client errors should remove the subscription.

* Improve titles, trim body to reasonable length

* Disallow cleartext HTTP for Web Push servers

* Fix lint

* Remove redundant index on unique column

Also removes redundant unique and notnull tags on ID column since these are implied by pk

* Make realsender.go more readable

* Use Tobi's style for wrapping errors

* Restore treating all 5xx codes as temporary problems

* Always load target account settings

* Stub `policy` and `standard`

* webpush.Sender: take type converter as ctor param

* Move webpush.MockSender and noopSender into testrig
2025-01-23 16:47:30 -08:00

95 lines
2.7 KiB
Go

// Copyright 2014 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
// Package hkdf implements the HMAC-based Extract-and-Expand Key Derivation
// Function (HKDF) as defined in RFC 5869.
//
// HKDF is a cryptographic key derivation function (KDF) with the goal of
// expanding limited input keying material into one or more cryptographically
// strong secret keys.
package hkdf
import (
"crypto/hmac"
"errors"
"hash"
"io"
)
// Extract generates a pseudorandom key for use with Expand from an input secret
// and an optional independent salt.
//
// Only use this function if you need to reuse the extracted key with multiple
// Expand invocations and different context values. Most common scenarios,
// including the generation of multiple keys, should use New instead.
func Extract(hash func() hash.Hash, secret, salt []byte) []byte {
if salt == nil {
salt = make([]byte, hash().Size())
}
extractor := hmac.New(hash, salt)
extractor.Write(secret)
return extractor.Sum(nil)
}
type hkdf struct {
expander hash.Hash
size int
info []byte
counter byte
prev []byte
buf []byte
}
func (f *hkdf) Read(p []byte) (int, error) {
// Check whether enough data can be generated
need := len(p)
remains := len(f.buf) + int(255-f.counter+1)*f.size
if remains < need {
return 0, errors.New("hkdf: entropy limit reached")
}
// Read any leftover from the buffer
n := copy(p, f.buf)
p = p[n:]
// Fill the rest of the buffer
for len(p) > 0 {
if f.counter > 1 {
f.expander.Reset()
}
f.expander.Write(f.prev)
f.expander.Write(f.info)
f.expander.Write([]byte{f.counter})
f.prev = f.expander.Sum(f.prev[:0])
f.counter++
// Copy the new batch into p
f.buf = f.prev
n = copy(p, f.buf)
p = p[n:]
}
// Save leftovers for next run
f.buf = f.buf[n:]
return need, nil
}
// Expand returns a Reader, from which keys can be read, using the given
// pseudorandom key and optional context info, skipping the extraction step.
//
// The pseudorandomKey should have been generated by Extract, or be a uniformly
// random or pseudorandom cryptographically strong key. See RFC 5869, Section
// 3.3. Most common scenarios will want to use New instead.
func Expand(hash func() hash.Hash, pseudorandomKey, info []byte) io.Reader {
expander := hmac.New(hash, pseudorandomKey)
return &hkdf{expander, expander.Size(), info, 1, nil, nil}
}
// New returns a Reader, from which keys can be read, using the given hash,
// secret, salt and context info. Salt and info can be nil.
func New(hash func() hash.Hash, secret, salt, info []byte) io.Reader {
prk := Extract(hash, secret, salt)
return Expand(hash, prk, info)
}