Restore old device signature so the proxy works again

[nickvergessen]

Reverting #1081

cc @bytepoets-mzi Not sure what's wrong with golang vs. php, but I have to revert this so push notifications work again for our devices.

Verification test on https://play.golang.org/ prints:

OK HashAfterSign
Invalid signature HashBeforeSign

Program exited.

Sample go code:

// You can edit this code!
// Click here and start typing.
package main

import (
	"crypto"
	"crypto/rsa"
	"crypto/x509"
	"encoding/base64"
	"encoding/pem"
	"fmt"
)

func main() {
	userPublicKey := `-----BEGIN PUBLIC KEY-----
MIIBIjANBgkqhkiG9w0BAQEFAAOCAQ8AMIIBCgKCAQEAwc4lFZz05CtWnRVIKkOz
vSZYfVZpD23K/7YVsoMZXsh7hrzJTFV6dmrJS01yTecF3I/tgL3Kt5kEyL2bRJpy
DUWRuqTWnqTnpbL6yTsMqeC/+eVPH3boCj6xEBEM2NQrNjUDnm2BFZszGyEHJj0B
LeBmOxBE1e7V4jBQGCrhoW9bLL1Oc434q7+pIFCSBT5a/ZQefqRrRWb68KjA9Xzq
1RA4z1MCBgejeC/k14Pg/xsr8Ixjw2SxOaFGcszInQemTvAeHplwlwmebKpW3Q0l
QAbwSfPUGX9TAUsOyhbazinEUpUXMmobHQM3matTRjcwYVbRpRSbG3XIxSsrfF2a
UwIDAQAB
-----END PUBLIC KEY-----`

	block, _ := pem.Decode([]byte(userPublicKey))
	if block == nil {
		fmt.Println("Invalid public key")
	}

	pub, err := x509.ParsePKIXPublicKey(block.Bytes)
	if err != nil || pub == nil {
		fmt.Println("Invalid public key")
	}

	publicKey, ok := pub.(*rsa.PublicKey)
	if !ok {
		fmt.Println("Invalid public key")
	}

	deviceIdentifierHashAfterSign := "JIFqiMjfu5uzeTqa2k++BimoukxtOwOAQjIT8MAZ8/5rbhXq085eXkUnaoJJWFTJ8u7jBVEWkIcuJYot1mhQUw=="
	deviceIdentifierSignatureHashAfterSign := "vYo3lnXW+fVjtI2+XRxWIidKY0iW6OLxcipe5ThuqGdfsXhJQhQHWuR7IUEmiLgPtiobHStFIVaddXfDhgZnDRLe//kKBRsPzfqRI1dS9Q0C+38DRz/loNMp/WXYs0Ug4CSkG5otVnbqtYErCluZ3gA/hhBAzRi+Jw4lGkECEVdpt5XEvAi0A/bF7KK04JUkSHcJGpuGtxUzqUhSpNRRVCyN8LY10Q59whwfd0zlEqgGq3Wv+7tFaoZsD7iQ7jWFmbtzF3Z4QV7E7zH33BFX8Bdzu3NdWfDmkBBaB0K6HESObkTv5+sX/Z6UJ1ETYdQed6H7E/FLTl5UN4CqCWEHPA=="

	rawDeviceIdentifierHashHashAfterSign, err := base64.StdEncoding.DecodeString(deviceIdentifierHashAfterSign)
	if err != nil {
		fmt.Println("Invalid input HashAfterSign")
	}

	signatureHashAfterSign, err := base64.StdEncoding.DecodeString(deviceIdentifierSignatureHashAfterSign)
	if err != nil {
		fmt.Println("Invalid signature data HashAfterSign")
	}

	if err = rsa.VerifyPKCS1v15(publicKey, crypto.SHA512, rawDeviceIdentifierHashHashAfterSign, signatureHashAfterSign); err != nil {
		fmt.Println("Invalid signature HashAfterSign")
	} else {
		fmt.Println("OK HashAfterSign")
	}
	
	deviceIdentifierHashBeforeSign := "396hZP/Ww13/fbg/7xyLHn789ZBfMBEnhX7gQBub7iWY0LhcPzOin28zM+bLwNSRNOOCbsspBEu1eZB61+rieA=="
	deviceIdentifierSignatureHashBeforeSign := "aZsxhwzLOFVigIp7SfOgxghIVu2sgCbipqmxwgEn2QBH0PA8/j0738MI90JtEe2Fv6mrg4Sjo7/CmCZlo/KCya6JahFtK4zy07CbLS7hX7y1ACBkJJ8CWfhxm/UHtwzG+DVN5UrelHYcTnq6+gGFAlZEKs2ehD3QEqGxHZuJKR8WsUYFIbdrcfqwpEjqT85jyr615+hBWDQuToQQa/xPzw2jotHPP7r5I2dTEwbxdHpThFA5Av9NT0RExLYaphti+lInN25JxqlWDIbVg4pHko3G0LS+ca4Eu1tV1NPwkilTVzAYYPpEi7tfYodbgoMzv/bs0gMpgA7E+pjz1sToAQ=="

	rawDeviceIdentifierHashHashBeforeSign, err := base64.StdEncoding.DecodeString(deviceIdentifierHashBeforeSign)
	if err != nil {
		fmt.Println("Invalid input HashBeforeSign")
	}

	signatureHashBeforeSign, err := base64.StdEncoding.DecodeString(deviceIdentifierSignatureHashBeforeSign)
	if err != nil {
		fmt.Println("Invalid signature data HashBeforeSign")
	}

	if err = rsa.VerifyPKCS1v15(publicKey, crypto.SHA512, rawDeviceIdentifierHashHashBeforeSign, signatureHashBeforeSign); err != nil {
		fmt.Println("Invalid signature HashBeforeSign")
	} else {
		fmt.Println("OK HashBeforeSign")
	}
}

[nickvergessen]

/backport to stable22

[nickvergessen]

/backport to stable21

[nickvergessen]

/backport to stable20

[timkrueger]

Push messages arrive again in Talk for Android.