/* Any copyright is dedicated to the Public Domain.
 * http://creativecommons.org/publicdomain/zero/1.0/ */

"use strict";

// Tests DER.jsm functionality.

var { DER } = Cu.import("resource://gre/modules/psm/DER.jsm", {});

function run_simple_tests() {
  throws(() => new DER.DER("this is not an array"), /invalid input/,
         "should throw given non-array input");
  throws(() => new DER.DER([0, "invalid input", 1]), /invalid input/,
         "should throw given non-byte data (string case)");
  throws(() => new DER.DER([31, 1, {}]), /invalid input/,
         "should throw given non-byte data (object case)");
  throws(() => new DER.DER([0.1, 3, 1]), /invalid input/,
         "should throw given non-byte data (non-integer case)");
  throws(() => new DER.DER([1, 3, -1]), /invalid input/,
         "should throw given non-byte data (negative integer case)");
  throws(() => new DER.DER([1, 300, 79]), /invalid input/,
         "should throw given non-byte data (large integer case)");

  let testReadByte = new DER.DER([0x0a, 0x0b]);
  equal(testReadByte.readByte(), 0x0a, "should read 0x0a");
  equal(testReadByte.readByte(), 0x0b, "should read 0x0b");
  throws(() => testReadByte.readByte(), /data truncated/,
         "reading more data than is available should fail");

  let testReadBytes = new DER.DER([0x0c, 0x0d, 0x0e]);
  deepEqual(testReadBytes.readBytes(3), [0x0c, 0x0d, 0x0e],
            "should read correct sequence of bytes");

  let testReadNegativeBytes = new DER.DER([0xff, 0xaf]);
  throws(() => testReadNegativeBytes.readBytes(-4), /invalid length/,
         "reading a negative number of bytes should fail");

  let testReadZeroBytes = new DER.DER([]);
  equal(testReadZeroBytes.readBytes(0).length, 0,
        "reading zero bytes should result in a zero-length array");

  let testReadTooManyBytes = new DER.DER([0xab, 0xcd, 0xef]);
  throws(() => testReadTooManyBytes.readBytes(4), /data truncated/,
         "reading too many bytes should fail");

  let testSEQUENCE = new DER.DER([0x30, 0x01, 0x01]);
  let content = testSEQUENCE.readTagAndGetContents(DER.SEQUENCE);
  equal(content.length, 1, "content should have length 1");
  equal(content[0], 1, "value of content should be [1]");
  ok(testSEQUENCE.atEnd(), "testSEQUENCE should be at the end of its input");
  testSEQUENCE.assertAtEnd();

  // The length purports to be 4 bytes, but there are only 2 available.
  let truncatedSEQUENCE = new DER.DER([0x30, 0x04, 0x00, 0x00]);
  throws(() => truncatedSEQUENCE.readTagAndGetContents(DER.SEQUENCE),
         /data truncated/, "should get 'data truncated' error");

  // With 2 bytes of content, there is 1 remaining after reading the content.
  let extraDataSEQUENCE = new DER.DER([0x30, 0x02, 0xab, 0xcd, 0xef]);
  content = extraDataSEQUENCE.readTagAndGetContents(DER.SEQUENCE);
  equal(content.length, 2, "content should have length 2");
  deepEqual(content, [0xab, 0xcd], "value of content should be [0xab, 0xcd]");
  ok(!extraDataSEQUENCE.atEnd(),
     "extraDataSEQUENCE should not be at the end of its input");
  throws(() => extraDataSEQUENCE.assertAtEnd(), /extra data/,
         "should get 'extra data' error");

  // The length of 0x81 0x01 is invalid because it could be encoded as just
  // 0x01, which is shorter.
  let invalidLengthSEQUENCE1 = new DER.DER([0x30, 0x81, 0x01, 0x00]);
  throws(() => invalidLengthSEQUENCE1.readTagAndGetContents(DER.SEQUENCE),
         /invalid length/, "should get 'invalid length' error");

  // Similarly, 0x82 0x00 0x01 could be encoded as just 0x01, which is shorter.
  let invalidLengthSEQUENCE2 = new DER.DER([0x30, 0x82, 0x00, 0x01, 0x00]);
  throws(() => invalidLengthSEQUENCE2.readTagAndGetContents(DER.SEQUENCE),
         /invalid length/, "should get 'invalid length' error");

  // Lengths requiring 4 bytes to encode are not supported.
  let unsupportedLengthSEQUENCE = new DER.DER([0x30, 0x83, 0x01, 0x01, 0x01]);
  throws(() => unsupportedLengthSEQUENCE.readTagAndGetContents(DER.SEQUENCE),
         /unsupported length/, "should get 'unsupported length' error");

  // Indefinite lengths are not supported (and aren't DER anyway).
  let unsupportedASN1SEQUENCE = new DER.DER([0x30, 0x80, 0x01, 0x00, 0x00]);
  throws(() => unsupportedASN1SEQUENCE.readTagAndGetContents(DER.SEQUENCE),
         /unsupported asn.1/, "should get 'unsupported asn.1' error");

  let unexpectedTag = new DER.DER([0x31, 0x01, 0x00]);
  throws(() => unexpectedTag.readTagAndGetContents(DER.SEQUENCE),
         /unexpected tag/, "should get 'unexpected tag' error");

  let readTLVTestcase = new DER.DER([0x02, 0x03, 0x45, 0x67, 0x89]);
  let bytes = readTLVTestcase.readTLV();
  deepEqual(bytes, [0x02, 0x03, 0x45, 0x67, 0x89],
            "bytes read with readTLV should be equal to expected value");

  let peekTagTestcase = new DER.DER([0x30, 0x01, 0x00]);
  ok(peekTagTestcase.peekTag(DER.SEQUENCE),
     "peekTag should return true for peeking with a SEQUENCE at a SEQUENCE");
  ok(!peekTagTestcase.peekTag(DER.SET),
     "peekTag should return false for peeking with a SET at a SEQUENCE");
  peekTagTestcase.readTLV();
  ok(!peekTagTestcase.peekTag(DER.SEQUENCE),
     "peekTag should return false for peeking at a DER with no more data");

  let tlvChoiceTestcase = new DER.DER([0x31, 0x02, 0xaa, 0xbb]);
  let tlvChoiceContents = tlvChoiceTestcase.readTLVChoice([DER.NULL, DER.SET]);
  deepEqual(tlvChoiceContents, [0x31, 0x02, 0xaa, 0xbb],
            "readTLVChoice should return expected bytes");

  let tlvChoiceNoMatchTestcase = new DER.DER([0x30, 0x01, 0xff]);
  throws(() => tlvChoiceNoMatchTestcase.readTLVChoice([DER.NULL, DER.SET]),
         /unexpected tag/,
         "readTLVChoice should throw if no matching tag is found");
}

function run_bit_string_tests() {
  let bitstringDER = new DER.DER([0x03, 0x04, 0x03, 0x01, 0x02, 0xf8]);
  let bitstring = bitstringDER.readBIT_STRING();
  equal(bitstring.unusedBits, 3, "BIT STRING should have 3 unused bits");
  deepEqual(bitstring.contents, [0x01, 0x02, 0xf8],
            "BIT STRING should have expected contents");

  let bitstringTooManyUnusedBits = new DER.DER([0x03, 0x02, 0x08, 0x00]);
  throws(() => bitstringTooManyUnusedBits.readBIT_STRING(),
         /invalid BIT STRING encoding/,
         "BIT STRING with too many unused bits should throw");

  // A BIT STRING must have the unused bits byte, and so its length must be at
  // least one.
  let bitstringMissingUnusedBits = new DER.DER([0x03, 0x00]);
  throws(() => bitstringMissingUnusedBits.readBIT_STRING(),
         /invalid BIT STRING encoding/,
         "BIT STRING with missing unused bits (and no contents) should throw");

  // The minimal BIT STRING is 03 01 00 (zero bits of padding and zero bytes of
  // content).
  let minimalBitstringDER = new DER.DER([0x03, 0x01, 0x00]);
  let minimalBitstring = minimalBitstringDER.readBIT_STRING();
  equal(minimalBitstring.unusedBits, 0,
       "minimal BIT STRING should have 0 unused bits");
  equal(minimalBitstring.contents.length, 0,
        "minimal BIT STRING should have empty contents");

  // However, a BIT STRING with zero bytes of content can't have any padding,
  // because that makes no sense.
  let noContentsPaddedBitstringDER = new DER.DER([0x03, 0x01, 0x03]);
  throws(() => noContentsPaddedBitstringDER.readBIT_STRING(),
          /invalid BIT STRING encoding/,
         "BIT STRING with no contents with non-zero padding should throw");
}

function run_compound_tests() {
  let derBytes =
    [ 0x30, 0x1a,                       // SEQUENCE
        0x02, 0x02, 0x77, 0xff,         //   INTEGER
        0x06, 0x03, 0x2b, 0x01, 0x01,   //   OBJECT IDENTIFIER
        0x30, 0x07,                     //   SEQUENCE
          0x05, 0x00,                   //     NULL
          0x02, 0x03, 0x45, 0x46, 0x47, //     INTEGER
        0x30, 0x06,                     //   SEQUENCE
          0x02, 0x02, 0x00, 0xff,       //     INTEGER
          0x05, 0x00 ];                 //     NULL
  let der = new DER.DER(derBytes);
  let contents = new DER.DER(der.readTagAndGetContents(DER.SEQUENCE));
  let firstINTEGER = contents.readTagAndGetContents(DER.INTEGER);
  deepEqual(firstINTEGER, [0x77, 0xff],
            "first INTEGER should have expected value");
  let oid = contents.readTagAndGetContents(DER.OBJECT_IDENTIFIER);
  deepEqual(oid, [0x2b, 0x01, 0x01],
            "OBJECT IDENTIFIER should have expected value");

  let firstNested = new DER.DER(contents.readTagAndGetContents(DER.SEQUENCE));
  let firstNestedNULL = firstNested.readTagAndGetContents(DER.NULL);
  equal(firstNestedNULL.length, 0,
        "first nested NULL should have expected value (empty array)");
  let firstNestedINTEGER = firstNested.readTagAndGetContents(DER.INTEGER);
  deepEqual(firstNestedINTEGER, [0x45, 0x46, 0x47],
            "first nested INTEGER should have expected value");
  firstNested.assertAtEnd();

  let secondNested = new DER.DER(contents.readTagAndGetContents(DER.SEQUENCE));
  let secondNestedINTEGER = secondNested.readTagAndGetContents(DER.INTEGER);
  deepEqual(secondNestedINTEGER, [0x00, 0xff],
            "second nested INTEGER should have expected value");
  let secondNestedNULL = secondNested.readTagAndGetContents(DER.NULL);
  equal(secondNestedNULL.length, 0,
        "second nested NULL should have expected value (empty array)");
  secondNested.assertAtEnd();

  contents.assertAtEnd();
  der.assertAtEnd();

  let invalidDERBytes =
    [ 0x30, 0x06,     // SEQUENCE
        0x30, 0x02,   //   SEQUENCE
          0x02, 0x01, //     INTEGER (missing data)
        0x05, 0x00,   //   NULL
      0x00, 0x00 ];   // (extra data)
  let invalidDER = new DER.DER(invalidDERBytes);
  let invalidContents = new DER.DER(
    invalidDER.readTagAndGetContents(DER.SEQUENCE));
  let invalidContentsContents = new DER.DER(
    invalidContents.readTagAndGetContents(DER.SEQUENCE));
  throws(() => invalidContentsContents.readTagAndGetContents(DER.INTEGER),
         /data truncated/, "should throw due to missing data");
  let nestedNULL = invalidContents.readTagAndGetContents(DER.NULL);
  equal(nestedNULL.length, 0, "nested NULL should have expected value");
  invalidContents.assertAtEnd();
  throws(() => invalidDER.assertAtEnd(), /extra data/,
         "should throw due to extra data");
}

function run_test() {
  run_simple_tests();
  run_bit_string_tests();
  run_compound_tests();
}