#!/bin/bash
# Cloudron OIDC dashboard login (SPA-mimic, PKCE) for an identity.
# usage: cloudron-oidc-login.sh <cloudron-username> [vault-item]
# Performs: prompt=login auth -> interaction login (password + TOTP from
# vault totp_seed if present) -> consent confirm -> code exchange.
# Writes the access token to /tmp/.oidc-bearer-<username> and a session
# cookie jar /tmp/oidc-jar-<username>.txt. Prints checkpoints to stderr.
set -uo pipefail
U="${1:?usage: cloudron-oidc-login.sh <cloudron-username> [vault-item]}"
ITEM="${2:-$U Cloudron}"
BASE="https://my.knownelement.com"
CLIENT="cid-webadmin"
REDIRECT="$BASE/authcallback.html" # used in the auth request below via explicit URL encoding
DBG="${CLOUDRON_SELF_DEBUG:-0}"
if [ "$(id -un)" = "TSGCOO" ]; then
  SM() { /data2/TSGCOO/.local/bin/sm "$@" </dev/null; }
else
  SM() { sudo -u TSGCOO /data2/TSGCOO/.local/bin/sm "$@" </dev/null; }
fi
PW=$(SM get "$ITEM" --field password)
[ -n "$PW" ] || { echo "FAIL: no password in vault item $ITEM" >&2; exit 1; }
SEED=$(SM get "$ITEM" --field totp_seed 2>/dev/null || true)
VERIFIER=$(openssl rand -base64 48 | tr '+/' '-_' | tr -d '=\n' | cut -c1-64)
CHALLENGE=$(printf '%s' "$VERIFIER" | openssl dgst -sha256 -binary | openssl base64 | tr '+/' '-_' | tr -d '=\n')
AUTH="$BASE/openid/auth?client_id=$CLIENT&response_type=code&scope=openid%20email%20profile&redirect_uri=https%3A%2F%2Fmy.knownelement.com%2Fauthcallback.html&code_challenge=$CHALLENGE&code_challenge_method=S256"
JAR="/tmp/oidc-jar-$U.txt"; rm -f "$JAR"

INT=$(curl -sk -o /dev/null -w '%{url_effective}' -c "$JAR" -L --max-redirs 8 "$AUTH")
[ "$DBG" = 1 ] && echo "DBG int: ${INT:0:70}" >&2
case "$INT" in */openid/interaction/*) : ;; *) echo "FAIL: no interaction (auto-resolved session?)"; exit 3;; esac
UIDPATH=$(printf '%s' "$INT" | grep -o '/openid/interaction/[^?]*')

BODY="{\"username\":\"$U\",\"password\":\"$PW\""
if [ -n "$SEED" ]; then
  TCODE=$(bash "$(dirname "$0")/totp.sh" "$SEED")
  BODY="$BODY,\"totpToken\":\"$TCODE\""
fi
BODY="$BODY}"
LOGIN_RESP=$(curl -sk -b "$JAR" -c "$JAR" -X POST "$BASE$UIDPATH/login" \
  -H 'Content-Type: application/json' -d "$BODY")
unset BODY
[ "$DBG" = 1 ] && echo "DBG login: ${LOGIN_RESP:0:70}" >&2
case "$LOGIN_RESP" in
  *redirectTo*) : ;;
  *twoFactorRequired*) echo "FAIL: 2FA required but no usable seed in vault" >&2; exit 4;;
  *) echo "FAIL: login rejected: $LOGIN_RESP" >&2; exit 5;;
esac
RED=$(printf '%s' "$LOGIN_RESP" | sed -n 's/.*"redirectTo":"\([^"]*\)".*/\1/p')
CALLBACK=$(curl -sk -b "$JAR" -c "$JAR" -o /dev/null -w '%{url_effective}' -L --max-redirs 8 "$RED")
[ "$DBG" = 1 ] && echo "DBG after resume: ${CALLBACK:0:70}" >&2

case "$CALLBACK" in
  */openid/interaction/*)
    CUIDPATH=$(printf '%s' "$CALLBACK" | grep -o '/openid/interaction/[^?]*')
    CLOC=$(curl -sk -b "$JAR" -c "$JAR" -D - -o /dev/null -X POST "$BASE$CUIDPATH/confirm" \
      -d '' | grep -i '^location:' | head -1 | tr -d '\r' | sed 's/^[Ll]ocation: //')
    [ -n "$CLOC" ] || { echo "FAIL: consent confirm produced no redirect" >&2; exit 6; }
    case "$CLOC" in http*) : ;; *) CLOC="$BASE$CLOC" ;; esac
    CALLBACK=$(curl -sk -b "$JAR" -c "$JAR" -o /dev/null -w '%{url_effective}' -L --max-redirs 8 "$CLOC")
    ;;
esac
CODE=$(printf '%s' "$CALLBACK" | sed -n 's/[?&]code=\([^&]*\).*/\1/p')
[ "$DBG" = 1 ] && echo "DBG code len: ${#CODE}" >&2
[ -n "$CODE" ] || { echo "FAIL: no authorization code at callback: $CALLBACK" >&2; exit 6; }

TOKRESP=$(curl -sk -b "$JAR" -c "$JAR" -X POST "$BASE/openid/token" \
  -H 'Content-Type: application/x-www-form-urlencoded' \
  --data-urlencode "grant_type=authorization_code" \
  --data-urlencode "code=$CODE" \
  --data-urlencode "client_id=$CLIENT" \
  --data-urlencode "redirect_uri=$REDIRECT" \
  --data-urlencode "code_verifier=$VERIFIER")
ACCESS=$(printf '%s' "$TOKRESP" | sed -n 's/.*"access_token":"\([^"]*\)".*/\1/p')
[ -n "$ACCESS" ] || { echo "FAIL: token exchange: $(printf '%s' "$TOKRESP" | head -c 120)" >&2; exit 7; }
printf '%s' "$ACCESS" > "/tmp/.oidc-bearer-$U"
chmod 600 "/tmp/.oidc-bearer-$U"
WHO=$(curl -sk "$BASE/api/v1/profile" -H "Authorization: Bearer $ACCESS" | sed -n 's/.*"username":"\([^"]*\)".*/\1/p')
echo "OK: bearer for '$WHO' at /tmp/.oidc-bearer-$U (session jar $JAR)"