#!/bin/sh

# Copyright (c) 2020 Fabian Henneke.
# Use of this source code is governed by a BSD-style
# license that can be found in the LICENSE file.
# SPDX-License-Identifier: BSD-2-Clause


if [ "$(uname)" != "Linux" ] ; then
   echo "Can only run on Linux"
   exit 1
fi

if ! TOKEN_VERSION=$("${FIDO_TOOLS_PREFIX}"fido2-token -V 2>&1); then
    echo "Please install libfido2 1.5.0 or higher"
    exit 1
fi

TOKEN_VERSION_MAJOR=$(echo "$TOKEN_VERSION" | cut -d. -f1)
TOKEN_VERSION_MINOR=$(echo "$TOKEN_VERSION" | cut -d. -f2)
if [ "$TOKEN_VERSION_MAJOR" -eq 0 ] ; then
    echo "Please install libfido2 1.5.0 or higher (current version: $TOKEN_VERSION)"
    exit 1
fi
if [ "$TOKEN_VERSION_MAJOR" -eq 1 ] && [ "$TOKEN_VERSION_MINOR" -lt 5 ] ; then
    echo "Please install libfido2 1.5.0 or higher (current version: $TOKEN_VERSION)"
    exit 1
fi

set -e

TOKEN_OUTPUT=$("${FIDO_TOOLS_PREFIX}"fido2-token -L)
DEV_PATH_NAMES=$(echo "$TOKEN_OUTPUT" | sed -r 's/^(.*): .*\((.*)\)$/\1 \2/g')
DEV_COUNT=$(echo "$DEV_PATH_NAMES" | wc -l)

for i in $(seq 1 "$DEV_COUNT")
do
    DEV_PATH_NAME=$(echo "$DEV_PATH_NAMES" | sed "${i}q;d")
    DEV_PATH=$(echo "$DEV_PATH_NAME" | cut -d' ' -f1)
    DEV_NAME=$(echo "$DEV_PATH_NAME" | cut -d' ' -f1 --complement)
    DEV_PRETTY="$DEV_NAME (at '$DEV_PATH')"
    if expr "$("${FIDO_TOOLS_PREFIX}"fido2-token -I "$DEV_PATH")" : ".* credMgmt.* clientPin.*\|.* clientPin.* credMgmt.*" > /dev/null ; then
        printf "Enter PIN for %s once (ignore further prompts): " "$DEV_PRETTY"
        stty -echo
        IFS= read -r PIN
        stty echo
        printf "\n"
        RESIDENT_RPS=$(printf "%s\n" "$PIN" | setsid -w "${FIDO_TOOLS_PREFIX}"fido2-token -L -r "$DEV_PATH" | cut -d' ' -f3)
        printf "\n"
        RESIDENT_RPS_COUNT=$(echo "$RESIDENT_RPS" | wc -l)
        FOUND=0
        for j in $(seq 1 "$RESIDENT_RPS_COUNT")
        do
            RESIDENT_RP=$(echo "$RESIDENT_RPS" | sed "${j}q;d")
            UNPROT_CREDS=$(printf "%s\n" "$PIN" | setsid -w "${FIDO_TOOLS_PREFIX}"fido2-token -L -k "$RESIDENT_RP" "$DEV_PATH" | grep ' uvopt$' | cut -d' ' -f2,3,4)
            printf "\n"
            UNPROT_CREDS_COUNT=$(echo "$UNPROT_CREDS" | wc -l)
            if [ "$UNPROT_CREDS_COUNT" -gt 0 ] ; then
                FOUND=1
                echo "Unprotected credentials on $DEV_PRETTY for '$RESIDENT_RP':"
                echo "$UNPROT_CREDS"
            fi
        done
        if [ $FOUND -eq 0 ] ; then
            echo "No unprotected credentials on $DEV_PRETTY"
        fi
    else
        echo "$DEV_PRETTY cannot enumerate credentials"
        echo "Discovering unprotected SSH credentials only..."
        STUB_HASH=$(printf "" | openssl sha256 -binary | base64)
        printf "%s\nssh:\n" "$STUB_HASH" | "${FIDO_TOOLS_PREFIX}"fido2-assert -G -r -t up=false "$DEV_PATH" 2> /dev/null || ASSERT_EXIT_CODE=$?
        if [ "$ASSERT_EXIT_CODE" -eq 0 ] ; then
            echo "Found an unprotected SSH credential on $DEV_PRETTY!"
        else
            echo "No unprotected SSH credentials (default settings) on $DEV_PRETTY"
        fi
    fi
    printf "\n"
done