spoof | Modify a message to have a desired CRC signature | Hashing library

No, this is not secure; the sender can easily be spoofed. The sender should authenticate their emails and as the recipient, you should verify that the email is authentic. If your incoming mail server adds (or can add when configured appropriately) an Authentication-Results header field (and removes existing such header fields), it's probably the easiest approach to simply rely on this field instead of verifying anything yourself.

Ignoring the problem of transport security, an alternative approach may be to simply include a secret token in the message (body or some header field – or even in the local part of both mail addresses).

Note that both approaches require full trust in the mailbox provider of both the sender and the recipient. If this is not acceptable for your threat model, you should look at end-to-end security or abolish this idea altogether.

Found something that works: setting the projection to be "RotatedPole" with the pole being about 90 degrees away at an azimuth perpendicular to the river. More generally, pick a pole so that the map's "up" points toward the pole and the map's left/right runs along the pole's equator.

1. Is this a question about browser tasing? If So - Safari > Develop > Enter Responsive Design Mode > Dropdown
2. Use an iPhone emulator.

Hopefully you are not accessing using any intermediaries who add headers.

I did some research into the link you shared, Django's source and Django REST Framework's source.

Bare-bones Django is not vulnerable to this, since it doesn't uses X-Forwarded-For, and neither is Python.

Virtually all versions of Django REST Framework are vulnerable, since this commit 9 years ago added the HTTP_X_FORWARDED_FOR check: https://github.com/encode/django-rest-framework/blob/d18d32669ac47178f26409f149160dc2c0c5359c/rest_framework/throttling.py#L155

For measures you can take to avoid this, since a patch is not yet available, you could implement your own ratelimitter, and replace get_ident to only use REMOTE_ADDR.

If your Djando REST Framework application is behind a proxy, you might not be vulnerable to this.

The ip4 checksum is only calculated over the ip header, if I get it correctly. So if you pass the total lenght of the whole packet to the checlsum calculation function, I would not be surprised, if you get a wrong checksum. I wonder though why it happend to work in the second program.

I asked the question simultaneously on the XDA Forums, and got a reply there.

At the stage described above (unlocked bootloader, Magisk, signature spoofing with riru + LSPosed), all that's needed is to install NanoDroid with microG as a Magisk module. Download the current NanoDroid-microG zip from here:

https://downloads.nanolx.org/NanoDroid/Stable/

either on your phone directly or transfer it to your phone, then install it as a Magisk module from storage. Voilà, GApps are removed (or at least inaccessible) and microG works. Best to then update microG, e.g. via its F-Droid repo: https://microg.org/download.html.

The purpose of shared secrets is both parties know the secret ahead of time, so it is not sent (otherwise it's no longer secret). Using your Twilio example, I checked the documentation and it doesn't say anything about additional headers other than the signature, and none of the parameters are a token either, so the auth token you mentioned is not included. Instead, both ends know the auth token, and they use it to generate/verify the signature.

If someone was to intercept and modify the message, they would need to know the secret to resign the message for it to be valid, and unless one side leaks the secret, the secret will remain unknown, and any modified data cannot be validly signed. If a token was passed around, the attacker only needs to intercept one sample, and then would be free to generate their own messages with the valid token. This is obviously less secure.

As for SSL, sources can be spoofed, and unless a client certificate is provided (which Twilio does not), there is no way to ascertain who sent the request, so SSL itself does not provide authentication.

May be I can explain this in two parts,

• First, there is no need for someone to spoof some header and pretend to be your domain. The reason is if someone can login as an anonymous from your domain directly they can access all the information which you have allowed them to access

• Second, and the most important one is, I think you have got the NodeJS server side access of firebase wrong. If you want to access the whole database from the node service use Firebase admin SDK and you don't have to do any kind of authentication to read to write when you connect from firebase admin SDK since you have admin access.

• FYI Also you can whitelist your auth ip from the Authentication settings where you can allow whitelisted domains

I was even unable to open ports on my server, so I reinstalled it. Everything works as it should since then.