#!/bin/bash
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#      http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
################################################################################

set -euo pipefail

#############################################################################
##### Tests for file_mac python example.

ROOT_DIR="$TEST_SRCDIR/tink"
FILE_MAC_CLI="$ROOT_DIR/examples/file_mac/python/file_mac_cleartext"

KEYSET_FILE="$ROOT_DIR/examples/file_mac/python/hmac_sha256_256bittag_test_keyset.json"
DATA_FILE="$TEST_TMPDIR/example_data.txt"
EXPECTED_MAC_FILE="$TEST_TMPDIR/expected_mac.txt"

echo "This is some message to be verified." > $DATA_FILE
CORRECT_MAC="01293CE659EBCFB08AF02C9B2E564D8352CD8EB58A363E7DE62BAA0BED9CA92BD257F76F4F"

#############################################################################

# A helper function for getting the return code of a command that may fail
# Temporarily disables error safety and stores return value in $TEST_STATUS
# Usage:
# % test_command somecommand some args
# % echo $TEST_STATUS
test_command() {
  set +e
  "$@"
  TEST_STATUS=$?
  set -e
}

#############################################################################
#### Test good key and correct MAC verification.
test_name="normal_verification"
echo "+++ Starting test $test_name..."

##### Create a plaintext and actual MAC.
echo "$CORRECT_MAC" > $EXPECTED_MAC_FILE

##### Run verification
test_command $FILE_MAC_CLI $KEYSET_FILE $DATA_FILE $EXPECTED_MAC_FILE

if [[ $TEST_STATUS -eq 0 ]]; then
  echo "+++ Success: MAC outputs matched."
else
  echo "--- Failure: the MAC outputs did not match"
  exit 1
fi


#############################################################################
#### Test good key and incorrect MAC verification.
test_name="incorrect_mac_verification"
echo "+++ Starting test $test_name..."

##### Create a plaintext and incorrect MAC.
echo "ABCABCABCD" > $EXPECTED_MAC_FILE

##### Run verification.
test_command $FILE_MAC_CLI $KEYSET_FILE $DATA_FILE $EXPECTED_MAC_FILE

if [[ $TEST_STATUS -ne 0 ]]; then
  echo "+++ Success: MAC verification reported non-match for incorrect MAC."
else
  echo "--- Failure: MAC verification reported match for incorrect MAC"
  exit 1
fi


#############################################################################
#### Test good key and non-hexadecimal MAC verification.
test_name="non_hex_mac_verification"
echo "+++ Starting test $test_name..."

##### Create a plaintext and non-hexadecimal MAC.
echo "SMDHTBFYGM" > $EXPECTED_MAC_FILE

##### Run verification.
test_command $FILE_MAC_CLI $KEYSET_FILE $DATA_FILE $EXPECTED_MAC_FILE

if [[ $TEST_STATUS -ne 0 ]]; then
  echo "+++ Success: MAC verification reported non-match for non-hex MAC."
else
  echo "--- Failure: MAC verification reported match for non-hex MAC"
  exit 1
fi


#############################################################################
#### Test good key MAC computation.
test_name="mac_computation"
echo "+++ Starting test $test_name..."

##### Create a plaintext and actual MAC.
MAC_OUTPUT_FILE="$TEST_TMPDIR/computed_mac_log.txt"

##### Run computation.
$FILE_MAC_CLI $KEYSET_FILE $DATA_FILE --alsologtostderr 2> $MAC_OUTPUT_FILE
##### Check that the correct MAC was produced in the logs
test_command grep --quiet --ignore-case "$CORRECT_MAC" "$MAC_OUTPUT_FILE"

if [[ $TEST_STATUS -eq 0 ]]; then
  echo "+++ Success: MAC computation was successful."
else
  echo "--- Failure: MAC computation was unsuccessful"
  exit 1
fi


#############################################################################
#### Test bad key MAC computation.
test_name="bad_key_computation"
echo "+++ Starting test $test_name..."

##### Create a plaintext and bad keyset.
BAD_KEY_FILE="$TEST_TMPDIR/bad_key.txt"
echo "not a key" > $BAD_KEY_FILE

##### Run computation.
test_command $FILE_MAC_CLI $BAD_KEY_FILE $DATA_FILE

if [[ $TEST_STATUS -ne 0 ]]; then
  echo "+++ Success: MAC computation failed with bad keyset."
else
  echo "--- Failure: MAC computation did not fail with bad keyset"
  exit 1
fi