/* Copyright (c) 2014, Google Inc.
 *
 * Permission to use, copy, modify, and/or distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
 * SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
 * OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
 * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */

#if !defined(__STDC_CONSTANT_MACROS)
#define __STDC_CONSTANT_MACROS
#endif

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#include <vector>

#include <openssl/bytestring.h>
#include <openssl/crypto.h>

#include "internal.h"
#include "../internal.h"


static bool TestSkip() {
  static const uint8_t kData[] = {1, 2, 3};
  CBS data;

  CBS_init(&data, kData, sizeof(kData));
  return CBS_len(&data) == 3 &&
      CBS_skip(&data, 1) &&
      CBS_len(&data) == 2 &&
      CBS_skip(&data, 2) &&
      CBS_len(&data) == 0 &&
      !CBS_skip(&data, 1);
}

static bool TestGetUint() {
  static const uint8_t kData[] = {1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11};
  uint8_t u8;
  uint16_t u16;
  uint32_t u32;
  CBS data;

  CBS_init(&data, kData, sizeof(kData));
  return CBS_get_u8(&data, &u8) &&
    u8 == 1 &&
    CBS_get_u16(&data, &u16) &&
    u16 == 0x203 &&
    CBS_get_u24(&data, &u32) &&
    u32 == 0x40506 &&
    CBS_get_u32(&data, &u32) &&
    u32 == 0x708090a &&
    CBS_get_last_u8(&data, &u8) &&
    u8 == 0xb &&
    !CBS_get_u8(&data, &u8) &&
    !CBS_get_last_u8(&data, &u8);
}

static bool TestGetPrefixed() {
  static const uint8_t kData[] = {1, 2, 0, 2, 3, 4, 0, 0, 3, 3, 2, 1};
  uint8_t u8;
  uint16_t u16;
  uint32_t u32;
  CBS data, prefixed;

  CBS_init(&data, kData, sizeof(kData));
  return CBS_get_u8_length_prefixed(&data, &prefixed) &&
    CBS_len(&prefixed) == 1 &&
    CBS_get_u8(&prefixed, &u8) &&
    u8 == 2 &&
    CBS_get_u16_length_prefixed(&data, &prefixed) &&
    CBS_len(&prefixed) == 2 &&
    CBS_get_u16(&prefixed, &u16) &&
    u16 == 0x304 &&
    CBS_get_u24_length_prefixed(&data, &prefixed) &&
    CBS_len(&prefixed) == 3 &&
    CBS_get_u24(&prefixed, &u32) &&
    u32 == 0x30201;
}

static bool TestGetPrefixedBad() {
  static const uint8_t kData1[] = {2, 1};
  static const uint8_t kData2[] = {0, 2, 1};
  static const uint8_t kData3[] = {0, 0, 2, 1};
  CBS data, prefixed;

  CBS_init(&data, kData1, sizeof(kData1));
  if (CBS_get_u8_length_prefixed(&data, &prefixed)) {
    return false;
  }

  CBS_init(&data, kData2, sizeof(kData2));
  if (CBS_get_u16_length_prefixed(&data, &prefixed)) {
    return false;
  }

  CBS_init(&data, kData3, sizeof(kData3));
  if (CBS_get_u24_length_prefixed(&data, &prefixed)) {
    return false;
  }

  return true;
}

static bool TestGetASN1() {
  static const uint8_t kData1[] = {0x30, 2, 1, 2};
  static const uint8_t kData2[] = {0x30, 3, 1, 2};
  static const uint8_t kData3[] = {0x30, 0x80};
  static const uint8_t kData4[] = {0x30, 0x81, 1, 1};
  static const uint8_t kData5[4 + 0x80] = {0x30, 0x82, 0, 0x80};
  static const uint8_t kData6[] = {0xa1, 3, 0x4, 1, 1};
  static const uint8_t kData7[] = {0xa1, 3, 0x4, 2, 1};
  static const uint8_t kData8[] = {0xa1, 3, 0x2, 1, 1};
  static const uint8_t kData9[] = {0xa1, 3, 0x2, 1, 0xff};

  CBS data, contents;
  int present;
  uint64_t value;

  CBS_init(&data, kData1, sizeof(kData1));
  if (CBS_peek_asn1_tag(&data, 0x1) ||
      !CBS_peek_asn1_tag(&data, 0x30)) {
    return false;
  }
  if (!CBS_get_asn1(&data, &contents, 0x30) ||
      CBS_len(&contents) != 2 ||
      OPENSSL_memcmp(CBS_data(&contents), "\x01\x02", 2) != 0) {
    return false;
  }

  CBS_init(&data, kData2, sizeof(kData2));
  // data is truncated
  if (CBS_get_asn1(&data, &contents, 0x30)) {
    return false;
  }

  CBS_init(&data, kData3, sizeof(kData3));
  // zero byte length of length
  if (CBS_get_asn1(&data, &contents, 0x30)) {
    return false;
  }

  CBS_init(&data, kData4, sizeof(kData4));
  // long form mistakenly used.
  if (CBS_get_asn1(&data, &contents, 0x30)) {
    return false;
  }

  CBS_init(&data, kData5, sizeof(kData5));
  // length takes too many bytes.
  if (CBS_get_asn1(&data, &contents, 0x30)) {
    return false;
  }

  CBS_init(&data, kData1, sizeof(kData1));
  // wrong tag.
  if (CBS_get_asn1(&data, &contents, 0x31)) {
    return false;
  }

  CBS_init(&data, NULL, 0);
  // peek at empty data.
  if (CBS_peek_asn1_tag(&data, 0x30)) {
    return false;
  }

  CBS_init(&data, NULL, 0);
  // optional elements at empty data.
  if (!CBS_get_optional_asn1(&data, &contents, &present, 0xa0) ||
      present ||
      !CBS_get_optional_asn1_octet_string(&data, &contents, &present, 0xa0) ||
      present ||
      CBS_len(&contents) != 0 ||
      !CBS_get_optional_asn1_octet_string(&data, &contents, NULL, 0xa0) ||
      CBS_len(&contents) != 0 ||
      !CBS_get_optional_asn1_uint64(&data, &value, 0xa0, 42) ||
      value != 42) {
    return false;
  }

  CBS_init(&data, kData6, sizeof(kData6));
  // optional element.
  if (!CBS_get_optional_asn1(&data, &contents, &present, 0xa0) ||
      present ||
      !CBS_get_optional_asn1(&data, &contents, &present, 0xa1) ||
      !present ||
      CBS_len(&contents) != 3 ||
      OPENSSL_memcmp(CBS_data(&contents), "\x04\x01\x01", 3) != 0) {
    return false;
  }

  CBS_init(&data, kData6, sizeof(kData6));
  // optional octet string.
  if (!CBS_get_optional_asn1_octet_string(&data, &contents, &present, 0xa0) ||
      present ||
      CBS_len(&contents) != 0 ||
      !CBS_get_optional_asn1_octet_string(&data, &contents, &present, 0xa1) ||
      !present ||
      CBS_len(&contents) != 1 ||
      CBS_data(&contents)[0] != 1) {
    return false;
  }

  CBS_init(&data, kData7, sizeof(kData7));
  // invalid optional octet string.
  if (CBS_get_optional_asn1_octet_string(&data, &contents, &present, 0xa1)) {
    return false;
  }

  CBS_init(&data, kData8, sizeof(kData8));
  // optional octet string.
  if (!CBS_get_optional_asn1_uint64(&data, &value, 0xa0, 42) ||
      value != 42 ||
      !CBS_get_optional_asn1_uint64(&data, &value, 0xa1, 42) ||
      value != 1) {
    return false;
  }

  CBS_init(&data, kData9, sizeof(kData9));
  // invalid optional integer.
  if (CBS_get_optional_asn1_uint64(&data, &value, 0xa1, 42)) {
    return false;
  }

  unsigned tag;
  CBS_init(&data, kData1, sizeof(kData1));
  if (!CBS_get_any_asn1(&data, &contents, &tag) ||
      tag != CBS_ASN1_SEQUENCE ||
      CBS_len(&contents) != 2 ||
      OPENSSL_memcmp(CBS_data(&contents), "\x01\x02", 2) != 0) {
    return false;
  }

  size_t header_len;
  CBS_init(&data, kData1, sizeof(kData1));
  if (!CBS_get_any_asn1_element(&data, &contents, &tag, &header_len) ||
      tag != CBS_ASN1_SEQUENCE ||
      header_len != 2 ||
      CBS_len(&contents) != 4 ||
      OPENSSL_memcmp(CBS_data(&contents), "\x30\x02\x01\x02", 2) != 0) {
    return false;
  }

  return true;
}

static bool TestGetOptionalASN1Bool() {
  static const uint8_t kTrue[] = {0x0a, 3, CBS_ASN1_BOOLEAN, 1, 0xff};
  static const uint8_t kFalse[] = {0x0a, 3, CBS_ASN1_BOOLEAN, 1, 0x00};
  static const uint8_t kInvalid[] = {0x0a, 3, CBS_ASN1_BOOLEAN, 1, 0x01};

  CBS data;
  CBS_init(&data, NULL, 0);
  int val = 2;
  if (!CBS_get_optional_asn1_bool(&data, &val, 0x0a, 0) ||
      val != 0) {
    return false;
  }

  CBS_init(&data, kTrue, sizeof(kTrue));
  val = 2;
  if (!CBS_get_optional_asn1_bool(&data, &val, 0x0a, 0) ||
      val != 1) {
    return false;
  }

  CBS_init(&data, kFalse, sizeof(kFalse));
  val = 2;
  if (!CBS_get_optional_asn1_bool(&data, &val, 0x0a, 1) ||
      val != 0) {
    return false;
  }

  CBS_init(&data, kInvalid, sizeof(kInvalid));
  if (CBS_get_optional_asn1_bool(&data, &val, 0x0a, 1)) {
    return false;
  }

  return true;
}

static bool TestCBBBasic() {
  static const uint8_t kExpected[] = {1, 2, 3, 4, 5, 6, 7, 8, 9, 0xa, 0xb, 0xc};
  uint8_t *buf;
  size_t buf_len;
  CBB cbb;

  if (!CBB_init(&cbb, 100)) {
    return false;
  }
  CBB_cleanup(&cbb);

  if (!CBB_init(&cbb, 0)) {
    return false;
  }
  if (!CBB_add_u8(&cbb, 1) ||
      !CBB_add_u16(&cbb, 0x203) ||
      !CBB_add_u24(&cbb, 0x40506) ||
      !CBB_add_u32(&cbb, 0x708090a) ||
      !CBB_add_bytes(&cbb, (const uint8_t*) "\x0b\x0c", 2) ||
      !CBB_finish(&cbb, &buf, &buf_len)) {
    CBB_cleanup(&cbb);
    return false;
  }

  bssl::UniquePtr<uint8_t> scoper(buf);
  return buf_len == sizeof(kExpected) &&
         OPENSSL_memcmp(buf, kExpected, buf_len) == 0;
}

static bool TestCBBFixed() {
  bssl::ScopedCBB cbb;
  uint8_t buf[1];
  uint8_t *out_buf;
  size_t out_size;

  if (!CBB_init_fixed(cbb.get(), NULL, 0) ||
      !CBB_finish(cbb.get(), &out_buf, &out_size) ||
      out_buf != NULL ||
      out_size != 0) {
    return false;
  }

  cbb.Reset();
  if (!CBB_init_fixed(cbb.get(), buf, 1) ||
      !CBB_add_u8(cbb.get(), 1) ||
      !CBB_finish(cbb.get(), &out_buf, &out_size) ||
      out_buf != buf ||
      out_size != 1 ||
      buf[0] != 1) {
    return false;
  }

  cbb.Reset();
  if (!CBB_init_fixed(cbb.get(), buf, 1) ||
      !CBB_add_u8(cbb.get(), 1) ||
      CBB_add_u8(cbb.get(), 2)) {
    return false;
  }

  return true;
}

static bool TestCBBFinishChild() {
  CBB cbb, child;
  uint8_t *out_buf;
  size_t out_size;

  if (!CBB_init(&cbb, 16)) {
    return false;
  }
  if (!CBB_add_u8_length_prefixed(&cbb, &child) ||
      CBB_finish(&child, &out_buf, &out_size) ||
      !CBB_finish(&cbb, &out_buf, &out_size)) {
    CBB_cleanup(&cbb);
    return false;
  }
  bssl::UniquePtr<uint8_t> scoper(out_buf);
  return out_size == 1 && out_buf[0] == 0;
}

static bool TestCBBPrefixed() {
  static const uint8_t kExpected[] = {0, 1, 1, 0, 2, 2, 3, 0, 0, 3,
                                      4, 5, 6, 5, 4, 1, 0, 1, 2};
  uint8_t *buf;
  size_t buf_len;
  CBB cbb, contents, inner_contents, inner_inner_contents;

  if (!CBB_init(&cbb, 0) ||
      CBB_len(&cbb) != 0 ||
      !CBB_add_u8_length_prefixed(&cbb, &contents) ||
      !CBB_add_u8_length_prefixed(&cbb, &contents) ||
      !CBB_add_u8(&contents, 1) ||
      CBB_len(&contents) != 1 ||
      !CBB_flush(&cbb) ||
      CBB_len(&cbb) != 3 ||
      !CBB_add_u16_length_prefixed(&cbb, &contents) ||
      !CBB_add_u16(&contents, 0x203) ||
      !CBB_add_u24_length_prefixed(&cbb, &contents) ||
      !CBB_add_u24(&contents, 0x40506) ||
      !CBB_add_u8_length_prefixed(&cbb, &contents) ||
      !CBB_add_u8_length_prefixed(&contents, &inner_contents) ||
      !CBB_add_u8(&inner_contents, 1) ||
      !CBB_add_u16_length_prefixed(&inner_contents, &inner_inner_contents) ||
      !CBB_add_u8(&inner_inner_contents, 2) ||
      !CBB_finish(&cbb, &buf, &buf_len)) {
    CBB_cleanup(&cbb);
    return false;
  }

  bssl::UniquePtr<uint8_t> scoper(buf);
  return buf_len == sizeof(kExpected) &&
         OPENSSL_memcmp(buf, kExpected, buf_len) == 0;
}

static bool TestCBBDiscardChild() {
  bssl::ScopedCBB cbb;
  CBB contents, inner_contents, inner_inner_contents;

  if (!CBB_init(cbb.get(), 0) ||
      !CBB_add_u8(cbb.get(), 0xaa)) {
    return false;
  }

  // Discarding |cbb|'s children preserves the byte written.
  CBB_discard_child(cbb.get());

  if (!CBB_add_u8_length_prefixed(cbb.get(), &contents) ||
      !CBB_add_u8_length_prefixed(cbb.get(), &contents) ||
      !CBB_add_u8(&contents, 0xbb) ||
      !CBB_add_u16_length_prefixed(cbb.get(), &contents) ||
      !CBB_add_u16(&contents, 0xcccc) ||
      !CBB_add_u24_length_prefixed(cbb.get(), &contents) ||
      !CBB_add_u24(&contents, 0xdddddd) ||
      !CBB_add_u8_length_prefixed(cbb.get(), &contents) ||
      !CBB_add_u8(&contents, 0xff) ||
      !CBB_add_u8_length_prefixed(&contents, &inner_contents) ||
      !CBB_add_u8(&inner_contents, 0x42) ||
      !CBB_add_u16_length_prefixed(&inner_contents, &inner_inner_contents) ||
      !CBB_add_u8(&inner_inner_contents, 0x99)) {
    return false;
  }

  // Discard everything from |inner_contents| down.
  CBB_discard_child(&contents);

  uint8_t *buf;
  size_t buf_len;
  if (!CBB_finish(cbb.get(), &buf, &buf_len)) {
    return false;
  }
  bssl::UniquePtr<uint8_t> scoper(buf);

  static const uint8_t kExpected[] = {
        0xaa,
        0,
        1, 0xbb,
        0, 2, 0xcc, 0xcc,
        0, 0, 3, 0xdd, 0xdd, 0xdd,
        1, 0xff,
  };
  return buf_len == sizeof(kExpected) &&
         OPENSSL_memcmp(buf, kExpected, buf_len) == 0;
}

static bool TestCBBMisuse() {
  CBB cbb, child, contents;
  uint8_t *buf;
  size_t buf_len;

  if (!CBB_init(&cbb, 0)) {
    return false;
  }
  if (!CBB_add_u8_length_prefixed(&cbb, &child) ||
      !CBB_add_u8(&child, 1) ||
      !CBB_add_u8(&cbb, 2)) {
    CBB_cleanup(&cbb);
    return false;
  }

  // Since we wrote to |cbb|, |child| is now invalid and attempts to write to
  // it should fail.
  if (CBB_add_u8(&child, 1) ||
      CBB_add_u16(&child, 1) ||
      CBB_add_u24(&child, 1) ||
      CBB_add_u8_length_prefixed(&child, &contents) ||
      CBB_add_u16_length_prefixed(&child, &contents) ||
      CBB_add_asn1(&child, &contents, 1) ||
      CBB_add_bytes(&child, (const uint8_t*) "a", 1)) {
    fprintf(stderr, "CBB operation on invalid CBB did not fail.\n");
    CBB_cleanup(&cbb);
    return false;
  }

  if (!CBB_finish(&cbb, &buf, &buf_len)) {
    CBB_cleanup(&cbb);
    return false;
  }
  bssl::UniquePtr<uint8_t> scoper(buf);

  if (buf_len != 3 ||
      OPENSSL_memcmp(buf, "\x01\x01\x02", 3) != 0) {
    return false;
  }
  return true;
}

static bool TestCBBASN1() {
  static const uint8_t kExpected[] = {0x30, 3, 1, 2, 3};
  uint8_t *buf;
  size_t buf_len;
  CBB cbb, contents, inner_contents;

  if (!CBB_init(&cbb, 0)) {
    return false;
  }
  if (!CBB_add_asn1(&cbb, &contents, 0x30) ||
      !CBB_add_bytes(&contents, (const uint8_t*) "\x01\x02\x03", 3) ||
      !CBB_finish(&cbb, &buf, &buf_len)) {
    CBB_cleanup(&cbb);
    return false;
  }
  bssl::UniquePtr<uint8_t> scoper(buf);

  if (buf_len != sizeof(kExpected) ||
      OPENSSL_memcmp(buf, kExpected, buf_len) != 0) {
    return false;
  }

  std::vector<uint8_t> test_data(100000, 0x42);

  if (!CBB_init(&cbb, 0)) {
    return false;
  }
  if (!CBB_add_asn1(&cbb, &contents, 0x30) ||
      !CBB_add_bytes(&contents, test_data.data(), 130) ||
      !CBB_finish(&cbb, &buf, &buf_len)) {
    CBB_cleanup(&cbb);
    return false;
  }
  scoper.reset(buf);

  if (buf_len != 3 + 130 ||
      OPENSSL_memcmp(buf, "\x30\x81\x82", 3) != 0 ||
      OPENSSL_memcmp(buf + 3, test_data.data(), 130) != 0) {
    return false;
  }

  if (!CBB_init(&cbb, 0)) {
    return false;
  }
  if (!CBB_add_asn1(&cbb, &contents, 0x30) ||
      !CBB_add_bytes(&contents, test_data.data(), 1000) ||
      !CBB_finish(&cbb, &buf, &buf_len)) {
    CBB_cleanup(&cbb);
    return false;
  }
  scoper.reset(buf);

  if (buf_len != 4 + 1000 ||
      OPENSSL_memcmp(buf, "\x30\x82\x03\xe8", 4) != 0 ||
      OPENSSL_memcmp(buf + 4, test_data.data(), 1000)) {
    return false;
  }

  if (!CBB_init(&cbb, 0)) {
    return false;
  }
  if (!CBB_add_asn1(&cbb, &contents, 0x30) ||
      !CBB_add_asn1(&contents, &inner_contents, 0x30) ||
      !CBB_add_bytes(&inner_contents, test_data.data(), 100000) ||
      !CBB_finish(&cbb, &buf, &buf_len)) {
    CBB_cleanup(&cbb);
    return false;
  }
  scoper.reset(buf);

  if (buf_len != 5 + 5 + 100000 ||
      OPENSSL_memcmp(buf, "\x30\x83\x01\x86\xa5\x30\x83\x01\x86\xa0", 10) !=
          0 ||
      OPENSSL_memcmp(buf + 10, test_data.data(), 100000)) {
    return false;
  }

  return true;
}

static bool DoBerConvert(const char *name,
                         const uint8_t *der_expected, size_t der_len,
                         const uint8_t *ber, size_t ber_len) {
  CBS in;
  uint8_t *out;
  size_t out_len;

  CBS_init(&in, ber, ber_len);
  if (!CBS_asn1_ber_to_der(&in, &out, &out_len)) {
    fprintf(stderr, "%s: CBS_asn1_ber_to_der failed.\n", name);
    return false;
  }
  bssl::UniquePtr<uint8_t> scoper(out);

  if (out == NULL) {
    if (ber_len != der_len ||
        OPENSSL_memcmp(der_expected, ber, ber_len) != 0) {
      fprintf(stderr, "%s: incorrect unconverted result.\n", name);
      return false;
    }

    return true;
  }

  if (out_len != der_len ||
      OPENSSL_memcmp(out, der_expected, der_len) != 0) {
    fprintf(stderr, "%s: incorrect converted result.\n", name);
    return false;
  }

  return true;
}

static bool TestBerConvert() {
  static const uint8_t kSimpleBER[] = {0x01, 0x01, 0x00};

  // kIndefBER contains a SEQUENCE with an indefinite length.
  static const uint8_t kIndefBER[] = {0x30, 0x80, 0x01, 0x01, 0x02, 0x00, 0x00};
  static const uint8_t kIndefDER[] = {0x30, 0x03, 0x01, 0x01, 0x02};

  // kOctetStringBER contains an indefinite length OCTET STRING with two parts.
  // These parts need to be concatenated in DER form.
  static const uint8_t kOctetStringBER[] = {0x24, 0x80, 0x04, 0x02, 0,    1,
                                            0x04, 0x02, 2,    3,    0x00, 0x00};
  static const uint8_t kOctetStringDER[] = {0x04, 0x04, 0, 1, 2, 3};

  // kNSSBER is part of a PKCS#12 message generated by NSS that uses indefinite
  // length elements extensively.
  static const uint8_t kNSSBER[] = {
      0x30, 0x80, 0x02, 0x01, 0x03, 0x30, 0x80, 0x06, 0x09, 0x2a, 0x86, 0x48,
      0x86, 0xf7, 0x0d, 0x01, 0x07, 0x01, 0xa0, 0x80, 0x24, 0x80, 0x04, 0x04,
      0x01, 0x02, 0x03, 0x04, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x30, 0x39,
      0x30, 0x21, 0x30, 0x09, 0x06, 0x05, 0x2b, 0x0e, 0x03, 0x02, 0x1a, 0x05,
      0x00, 0x04, 0x14, 0x84, 0x98, 0xfc, 0x66, 0x33, 0xee, 0xba, 0xe7, 0x90,
      0xc1, 0xb6, 0xe8, 0x8f, 0xfe, 0x1d, 0xc5, 0xa5, 0x97, 0x93, 0x3e, 0x04,
      0x10, 0x38, 0x62, 0xc6, 0x44, 0x12, 0xd5, 0x30, 0x00, 0xf8, 0xf2, 0x1b,
      0xf0, 0x6e, 0x10, 0x9b, 0xb8, 0x02, 0x02, 0x07, 0xd0, 0x00, 0x00,
  };

  static const uint8_t kNSSDER[] = {
      0x30, 0x53, 0x02, 0x01, 0x03, 0x30, 0x13, 0x06, 0x09, 0x2a, 0x86,
      0x48, 0x86, 0xf7, 0x0d, 0x01, 0x07, 0x01, 0xa0, 0x06, 0x04, 0x04,
      0x01, 0x02, 0x03, 0x04, 0x30, 0x39, 0x30, 0x21, 0x30, 0x09, 0x06,
      0x05, 0x2b, 0x0e, 0x03, 0x02, 0x1a, 0x05, 0x00, 0x04, 0x14, 0x84,
      0x98, 0xfc, 0x66, 0x33, 0xee, 0xba, 0xe7, 0x90, 0xc1, 0xb6, 0xe8,
      0x8f, 0xfe, 0x1d, 0xc5, 0xa5, 0x97, 0x93, 0x3e, 0x04, 0x10, 0x38,
      0x62, 0xc6, 0x44, 0x12, 0xd5, 0x30, 0x00, 0xf8, 0xf2, 0x1b, 0xf0,
      0x6e, 0x10, 0x9b, 0xb8, 0x02, 0x02, 0x07, 0xd0,
  };

  // kConstructedStringBER contains a deeply-nested constructed OCTET STRING.
  // The BER conversion collapses this to one level deep, but not completely.
  static const uint8_t kConstructedStringBER[] = {
      0xa0, 0x10, 0x24, 0x06, 0x04, 0x01, 0x00, 0x04, 0x01,
      0x01, 0x24, 0x06, 0x04, 0x01, 0x02, 0x04, 0x01, 0x03,
  };
  static const uint8_t kConstructedStringDER[] = {
      0xa0, 0x08, 0x04, 0x02, 0x00, 0x01, 0x04, 0x02, 0x02, 0x03,
  };

  return DoBerConvert("kSimpleBER", kSimpleBER, sizeof(kSimpleBER),
                      kSimpleBER, sizeof(kSimpleBER)) &&
         DoBerConvert("kIndefBER", kIndefDER, sizeof(kIndefDER), kIndefBER,
                      sizeof(kIndefBER)) &&
         DoBerConvert("kOctetStringBER", kOctetStringDER,
                      sizeof(kOctetStringDER), kOctetStringBER,
                      sizeof(kOctetStringBER)) &&
         DoBerConvert("kNSSBER", kNSSDER, sizeof(kNSSDER), kNSSBER,
                      sizeof(kNSSBER)) &&
         DoBerConvert("kConstructedStringBER", kConstructedStringDER,
                      sizeof(kConstructedStringDER), kConstructedStringBER,
                      sizeof(kConstructedStringBER));
}

struct ImplicitStringTest {
  const char *in;
  size_t in_len;
  bool ok;
  const char *out;
  size_t out_len;
};

static const ImplicitStringTest kImplicitStringTests[] = {
    // A properly-encoded string.
    {"\x80\x03\x61\x61\x61", 5, true, "aaa", 3},
    // An implicit-tagged string.
    {"\xa0\x09\x04\x01\x61\x04\x01\x61\x04\x01\x61", 11, true, "aaa", 3},
    // |CBS_get_asn1_implicit_string| only accepts one level deep of nesting.
    {"\xa0\x0b\x24\x06\x04\x01\x61\x04\x01\x61\x04\x01\x61", 13, false, nullptr,
     0},
    // The outer tag must match.
    {"\x81\x03\x61\x61\x61", 5, false, nullptr, 0},
    {"\xa1\x09\x04\x01\x61\x04\x01\x61\x04\x01\x61", 11, false, nullptr, 0},
    // The inner tag must match.
    {"\xa1\x09\x0c\x01\x61\x0c\x01\x61\x0c\x01\x61", 11, false, nullptr, 0},
};

static bool TestImplicitString() {
  for (const auto &test : kImplicitStringTests) {
    uint8_t *storage = nullptr;
    CBS in, out;
    CBS_init(&in, reinterpret_cast<const uint8_t *>(test.in), test.in_len);
    int ok = CBS_get_asn1_implicit_string(&in, &out, &storage,
                                          CBS_ASN1_CONTEXT_SPECIFIC | 0,
                                          CBS_ASN1_OCTETSTRING);
    bssl::UniquePtr<uint8_t> scoper(storage);

    if (static_cast<bool>(ok) != test.ok) {
      fprintf(stderr, "CBS_get_asn1_implicit_string unexpectedly %s\n",
              ok ? "succeeded" : "failed");
      return false;
    }

    if (ok && (CBS_len(&out) != test.out_len ||
               OPENSSL_memcmp(CBS_data(&out), test.out, test.out_len) != 0)) {
      fprintf(stderr, "CBS_get_asn1_implicit_string gave the wrong output\n");
      return false;
    }
  }

  return true;
}

struct ASN1Uint64Test {
  uint64_t value;
  const char *encoding;
  size_t encoding_len;
};

static const ASN1Uint64Test kASN1Uint64Tests[] = {
    {0, "\x02\x01\x00", 3},
    {1, "\x02\x01\x01", 3},
    {127, "\x02\x01\x7f", 3},
    {128, "\x02\x02\x00\x80", 4},
    {0xdeadbeef, "\x02\x05\x00\xde\xad\xbe\xef", 7},
    {UINT64_C(0x0102030405060708),
     "\x02\x08\x01\x02\x03\x04\x05\x06\x07\x08", 10},
    {UINT64_C(0xffffffffffffffff),
      "\x02\x09\x00\xff\xff\xff\xff\xff\xff\xff\xff", 11},
};

struct ASN1InvalidUint64Test {
  const char *encoding;
  size_t encoding_len;
};

static const ASN1InvalidUint64Test kASN1InvalidUint64Tests[] = {
    // Bad tag.
    {"\x03\x01\x00", 3},
    // Empty contents.
    {"\x02\x00", 2},
    // Negative number.
    {"\x02\x01\x80", 3},
    // Overflow.
    {"\x02\x09\x01\x00\x00\x00\x00\x00\x00\x00\x00", 11},
    // Leading zeros.
    {"\x02\x02\x00\x01", 4},
};

static bool TestASN1Uint64() {
  for (size_t i = 0; i < OPENSSL_ARRAY_SIZE(kASN1Uint64Tests); i++) {
    const ASN1Uint64Test *test = &kASN1Uint64Tests[i];
    CBS cbs;
    uint64_t value;
    CBB cbb;
    uint8_t *out;
    size_t len;

    CBS_init(&cbs, (const uint8_t *)test->encoding, test->encoding_len);
    if (!CBS_get_asn1_uint64(&cbs, &value) ||
        CBS_len(&cbs) != 0 ||
        value != test->value) {
      return false;
    }

    if (!CBB_init(&cbb, 0)) {
      return false;
    }
    if (!CBB_add_asn1_uint64(&cbb, test->value) ||
        !CBB_finish(&cbb, &out, &len)) {
      CBB_cleanup(&cbb);
      return false;
    }
    bssl::UniquePtr<uint8_t> scoper(out);
    if (len != test->encoding_len ||
        OPENSSL_memcmp(out, test->encoding, len) != 0) {
      return false;
    }
  }

  for (size_t i = 0; i < OPENSSL_ARRAY_SIZE(kASN1InvalidUint64Tests); i++) {
    const ASN1InvalidUint64Test *test = &kASN1InvalidUint64Tests[i];
    CBS cbs;
    uint64_t value;

    CBS_init(&cbs, (const uint8_t *)test->encoding, test->encoding_len);
    if (CBS_get_asn1_uint64(&cbs, &value)) {
      return false;
    }
  }

  return true;
}

static bool TestZero() {
  CBB cbb;
  CBB_zero(&cbb);
  // Calling |CBB_cleanup| on a zero-state |CBB| must not crash.
  CBB_cleanup(&cbb);
  return true;
}

static bool TestCBBReserve() {
  uint8_t buf[10];
  uint8_t *ptr;
  size_t len;
  bssl::ScopedCBB cbb;
  if (!CBB_init_fixed(cbb.get(), buf, sizeof(buf)) ||
      // Too large.
      CBB_reserve(cbb.get(), &ptr, 11)) {
    return false;
  }

  cbb.Reset();
  if (!CBB_init_fixed(cbb.get(), buf, sizeof(buf)) ||
      // Successfully reserve the entire space.
      !CBB_reserve(cbb.get(), &ptr, 10) ||
      ptr != buf ||
      // Advancing under the maximum bytes is legal.
      !CBB_did_write(cbb.get(), 5) ||
      !CBB_finish(cbb.get(), NULL, &len) ||
      len != 5) {
    return false;
  }
  return true;
}

static bool TestStickyError() {
  // Write an input that exceeds the limit for its length prefix.
  bssl::ScopedCBB cbb;
  CBB child;
  static const uint8_t kZeros[256] = {0};
  if (!CBB_init(cbb.get(), 0) ||
      !CBB_add_u8_length_prefixed(cbb.get(), &child) ||
      !CBB_add_bytes(&child, kZeros, sizeof(kZeros))) {
    return false;
  }

  if (CBB_flush(cbb.get())) {
    fprintf(stderr, "CBB_flush unexpectedly succeeded.\n");
    return false;
  }

  // All future operations should fail.
  uint8_t *ptr;
  size_t len;
  if (CBB_add_u8(cbb.get(), 0) ||
      CBB_finish(cbb.get(), &ptr, &len)) {
    fprintf(stderr, "Future operations unexpectedly succeeded.\n");
    return false;
  }

  // Write an input that cannot fit in a fixed CBB.
  cbb.Reset();
  uint8_t buf;
  if (!CBB_init_fixed(cbb.get(), &buf, 1)) {
    return false;
  }

  if (CBB_add_bytes(cbb.get(), kZeros, sizeof(kZeros))) {
    fprintf(stderr, "CBB_add_bytes unexpectedly succeeded.\n");
    return false;
  }

  // All future operations should fail.
  if (CBB_add_u8(cbb.get(), 0) ||
      CBB_finish(cbb.get(), &ptr, &len)) {
    fprintf(stderr, "Future operations unexpectedly succeeded.\n");
    return false;
  }

  // Write a u32 that cannot fit in a u24.
  cbb.Reset();
  if (!CBB_init(cbb.get(), 0)) {
    return false;
  }

  if (CBB_add_u24(cbb.get(), 1u << 24)) {
    fprintf(stderr, "CBB_add_u24 unexpectedly succeeded.\n");
    return false;
  }

  // All future operations should fail.
  if (CBB_add_u8(cbb.get(), 0) ||
      CBB_finish(cbb.get(), &ptr, &len)) {
    fprintf(stderr, "Future operations unexpectedly succeeded.\n");
    return false;
  }

  return true;
}

static bool TestBitString() {
  static const std::vector<uint8_t> kValidBitStrings[] = {
      {0x00},                                      // 0 bits
      {0x07, 0x80},                                // 1 bit
      {0x04, 0xf0},                                // 4 bits
      {0x00, 0xff},                                // 8 bits
      {0x06, 0xff, 0xff, 0xff, 0xff, 0xff, 0xc0},  // 42 bits
  };
  for (const auto& test : kValidBitStrings) {
    CBS cbs;
    CBS_init(&cbs, test.data(), test.size());
    if (!CBS_is_valid_asn1_bitstring(&cbs)) {
      return false;
    }
  }

  static const std::vector<uint8_t> kInvalidBitStrings[] = {
      // BIT STRINGs always have a leading byte.
      std::vector<uint8_t>{},
      // It's not possible to take an unused bit off the empty string.
      {0x01},
      // There can be at most 7 unused bits.
      {0x08, 0xff},
      {0xff, 0xff},
      // All unused bits must be cleared.
      {0x06, 0xff, 0xc1},
  };
  for (const auto& test : kInvalidBitStrings) {
    CBS cbs;
    CBS_init(&cbs, test.data(), test.size());
    if (CBS_is_valid_asn1_bitstring(&cbs)) {
      return false;
    }

    // CBS_asn1_bitstring_has_bit returns false on invalid inputs.
    if (CBS_asn1_bitstring_has_bit(&cbs, 0)) {
      return false;
    }
  }

  static const struct {
    std::vector<uint8_t> in;
    unsigned bit;
    bool bit_set;
  } kBitTests[] = {
      // Basic tests.
      {{0x00}, 0, false},
      {{0x07, 0x80}, 0, true},
      {{0x06, 0x0f, 0x40}, 0, false},
      {{0x06, 0x0f, 0x40}, 1, false},
      {{0x06, 0x0f, 0x40}, 2, false},
      {{0x06, 0x0f, 0x40}, 3, false},
      {{0x06, 0x0f, 0x40}, 4, true},
      {{0x06, 0x0f, 0x40}, 5, true},
      {{0x06, 0x0f, 0x40}, 6, true},
      {{0x06, 0x0f, 0x40}, 7, true},
      {{0x06, 0x0f, 0x40}, 8, false},
      {{0x06, 0x0f, 0x40}, 9, true},
      // Out-of-bounds bits return 0.
      {{0x06, 0x0f, 0x40}, 10, false},
      {{0x06, 0x0f, 0x40}, 15, false},
      {{0x06, 0x0f, 0x40}, 16, false},
      {{0x06, 0x0f, 0x40}, 1000, false},
  };
  for (const auto& test : kBitTests) {
    CBS cbs;
    CBS_init(&cbs, test.in.data(), test.in.size());
    if (CBS_asn1_bitstring_has_bit(&cbs, test.bit) !=
        static_cast<int>(test.bit_set)) {
      return false;
    }
  }

  return true;
}

int main() {
  CRYPTO_library_init();

  if (!TestSkip() ||
      !TestGetUint() ||
      !TestGetPrefixed() ||
      !TestGetPrefixedBad() ||
      !TestGetASN1() ||
      !TestCBBBasic() ||
      !TestCBBFixed() ||
      !TestCBBFinishChild() ||
      !TestCBBMisuse() ||
      !TestCBBPrefixed() ||
      !TestCBBDiscardChild() ||
      !TestCBBASN1() ||
      !TestBerConvert() ||
      !TestImplicitString() ||
      !TestASN1Uint64() ||
      !TestGetOptionalASN1Bool() ||
      !TestZero() ||
      !TestCBBReserve() ||
      !TestStickyError() ||
      !TestBitString()) {
    return 1;
  }

  printf("PASS\n");
  return 0;
}