Script for generating an user API key for discourse.

generate_api_key.py

"""
Script for generating an user API key for discourse.

Requirements:
pip install pycryptodomex

Usage:
python generate_api_key.py --help
python generate_api_key.py https://meta.discourse.org
"""
import argparse
from base64 import b64decode
import json
from secrets import token_urlsafe
from urllib.parse import urlencode

from Cryptodome.Cipher import PKCS1_v1_5
from Cryptodome.PublicKey import RSA
from Cryptodome.Random import get_random_bytes


def generate_api_key(host):
    # generate RSA key
    key = RSA.generate(2048)

    # assemble the url
    path = "/user-api-key/new"
    query_dict = {
        "application_name": "python",
        "client_id": token_urlsafe(),
        "scopes": "read",
        "public_key": key.publickey().export_key().decode(),
        "nonce": 1,
    }
    query = urlencode(query_dict)
    url = f"{host}{path}?{query}"
    print(f"Navigate to {url} and copy the generated ciphertext in here:\n")
    ciphertext = input()

    # process the ciphertext from discourse
    sentinel = get_random_bytes(16)
    cipher_rsa = PKCS1_v1_5.new(key)
    plaintext = cipher_rsa.decrypt(b64decode(ciphertext), sentinel)
    plaintext = json.loads(plaintext.decode())
    return plaintext["key"]


def main():
    parser = argparse.ArgumentParser()
    parser.add_argument("host", type=str, help="Hostname of the discourse server.")
    args = parser.parse_args()

    api_key = generate_api_key(args.host)
    print("\nUser API key:", api_key)


if __name__ == "__main__":
    main()

same problem here.
the problem is the client_id. This is how to fix it:

Thanks for investigating and providing the fix @call-me-matt! I updated the script.