/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
 * All rights reserved.
 *
 * This package is an SSL implementation written
 * by Eric Young (eay@cryptsoft.com).
 * The implementation was written so as to conform with Netscapes SSL.
 *
 * This library is free for commercial and non-commercial use as long as
 * the following conditions are aheared to.  The following conditions
 * apply to all code found in this distribution, be it the RC4, RSA,
 * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
 * included with this distribution is covered by the same copyright terms
 * except that the holder is Tim Hudson (tjh@cryptsoft.com).
 *
 * Copyright remains Eric Young's, and as such any Copyright notices in
 * the code are not to be removed.
 * If this package is used in a product, Eric Young should be given attribution
 * as the author of the parts of the library used.
 * This can be in the form of a textual message at program startup or
 * in documentation (online or textual) provided with the package.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *    "This product includes cryptographic software written by
 *     Eric Young (eay@cryptsoft.com)"
 *    The word 'cryptographic' can be left out if the rouines from the library
 *    being used are not cryptographic related :-).
 * 4. If you include any Windows specific code (or a derivative thereof) from
 *    the apps directory (application code) you must include an acknowledgement:
 *    "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
 *
 * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 * The licence and distribution terms for any publically available version or
 * derivative of this code cannot be changed.  i.e. this code cannot simply be
 * copied and put under another distribution licence
 * [including the GNU Public Licence.]
 *
 * The DSS routines are based on patches supplied by
 * Steven Schoch <schoch@sheba.arc.nasa.gov>. */

#include <openssl/dsa.h>

#include <string.h>

#include <openssl/bn.h>
#include <openssl/crypto.h>
#include <openssl/err.h>

#include "internal.h"


static int dsa_cb(int p, int n, BN_GENCB *arg);

/* The following values are taken from the updated Appendix 5 to FIPS PUB 186
 * and also appear in Appendix 5 to FIPS PUB 186-1. */

static const uint8_t seed[20] = {
    0xd5, 0x01, 0x4e, 0x4b, 0x60, 0xef, 0x2b, 0xa8, 0xb6, 0x21, 0x1b,
    0x40, 0x62, 0xba, 0x32, 0x24, 0xe0, 0x42, 0x7d, 0xd3,
};

static const uint8_t fips_p[] = {
    0x8d, 0xf2, 0xa4, 0x94, 0x49, 0x22, 0x76, 0xaa, 0x3d, 0x25, 0x75,
    0x9b, 0xb0, 0x68, 0x69, 0xcb, 0xea, 0xc0, 0xd8, 0x3a, 0xfb, 0x8d,
    0x0c, 0xf7, 0xcb, 0xb8, 0x32, 0x4f, 0x0d, 0x78, 0x82, 0xe5, 0xd0,
    0x76, 0x2f, 0xc5, 0xb7, 0x21, 0x0e, 0xaf, 0xc2, 0xe9, 0xad, 0xac,
    0x32, 0xab, 0x7a, 0xac, 0x49, 0x69, 0x3d, 0xfb, 0xf8, 0x37, 0x24,
    0xc2, 0xec, 0x07, 0x36, 0xee, 0x31, 0xc8, 0x02, 0x91,
};

static const uint8_t fips_q[] = {
    0xc7, 0x73, 0x21, 0x8c, 0x73, 0x7e, 0xc8, 0xee, 0x99, 0x3b, 0x4f,
    0x2d, 0xed, 0x30, 0xf4, 0x8e, 0xda, 0xce, 0x91, 0x5f,
};

static const uint8_t fips_g[] = {
    0x62, 0x6d, 0x02, 0x78, 0x39, 0xea, 0x0a, 0x13, 0x41, 0x31, 0x63,
    0xa5, 0x5b, 0x4c, 0xb5, 0x00, 0x29, 0x9d, 0x55, 0x22, 0x95, 0x6c,
    0xef, 0xcb, 0x3b, 0xff, 0x10, 0xf3, 0x99, 0xce, 0x2c, 0x2e, 0x71,
    0xcb, 0x9d, 0xe5, 0xfa, 0x24, 0xba, 0xbf, 0x58, 0xe5, 0xb7, 0x95,
    0x21, 0x92, 0x5c, 0x9c, 0xc4, 0x2e, 0x9f, 0x6f, 0x46, 0x4b, 0x08,
    0x8c, 0xc5, 0x72, 0xaf, 0x53, 0xe6, 0xd7, 0x88, 0x02,
};

static const uint8_t fips_x[] = {
    0x20, 0x70, 0xb3, 0x22, 0x3d, 0xba, 0x37, 0x2f, 0xde, 0x1c, 0x0f,
    0xfc, 0x7b, 0x2e, 0x3b, 0x49, 0x8b, 0x26, 0x06, 0x14,
};

static const uint8_t fips_y[] = {
    0x19, 0x13, 0x18, 0x71, 0xd7, 0x5b, 0x16, 0x12, 0xa8, 0x19, 0xf2,
    0x9d, 0x78, 0xd1, 0xb0, 0xd7, 0x34, 0x6f, 0x7a, 0xa7, 0x7b, 0xb6,
    0x2a, 0x85, 0x9b, 0xfd, 0x6c, 0x56, 0x75, 0xda, 0x9d, 0x21, 0x2d,
    0x3a, 0x36, 0xef, 0x16, 0x72, 0xef, 0x66, 0x0b, 0x8c, 0x7c, 0x25,
    0x5c, 0xc0, 0xec, 0x74, 0x85, 0x8f, 0xba, 0x33, 0xf4, 0x4c, 0x06,
    0x69, 0x96, 0x30, 0xa7, 0x6b, 0x03, 0x0e, 0xe3, 0x33,
};

static const uint8_t fips_digest[] = {
    0xa9, 0x99, 0x3e, 0x36, 0x47, 0x06, 0x81, 0x6a, 0xba, 0x3e, 0x25,
    0x71, 0x78, 0x50, 0xc2, 0x6c, 0x9c, 0xd0, 0xd8, 0x9d,
};

/* fips_sig is a DER-encoded version of the r and s values in FIPS PUB 186-1. */
static const uint8_t fips_sig[] = {
    0x30, 0x2d, 0x02, 0x15, 0x00, 0x8b, 0xac, 0x1a, 0xb6, 0x64, 0x10,
    0x43, 0x5c, 0xb7, 0x18, 0x1f, 0x95, 0xb1, 0x6a, 0xb9, 0x7c, 0x92,
    0xb3, 0x41, 0xc0, 0x02, 0x14, 0x41, 0xe2, 0x34, 0x5f, 0x1f, 0x56,
    0xdf, 0x24, 0x58, 0xf4, 0x26, 0xd1, 0x55, 0xb4, 0xba, 0x2d, 0xb6,
    0xdc, 0xd8, 0xc8,
};

/* fips_sig_negative is fips_sig with r encoded as a negative number. */
static const uint8_t fips_sig_negative[] = {
    0x30, 0x2c, 0x02, 0x14, 0x8b, 0xac, 0x1a, 0xb6, 0x64, 0x10, 0x43,
    0x5c, 0xb7, 0x18, 0x1f, 0x95, 0xb1, 0x6a, 0xb9, 0x7c, 0x92, 0xb3,
    0x41, 0xc0, 0x02, 0x14, 0x41, 0xe2, 0x34, 0x5f, 0x1f, 0x56, 0xdf,
    0x24, 0x58, 0xf4, 0x26, 0xd1, 0x55, 0xb4, 0xba, 0x2d, 0xb6, 0xdc,
    0xd8, 0xc8,
};

/* fip_sig_extra is fips_sig with trailing data. */
static const uint8_t fips_sig_extra[] = {
    0x30, 0x2d, 0x02, 0x15, 0x00, 0x8b, 0xac, 0x1a, 0xb6, 0x64, 0x10,
    0x43, 0x5c, 0xb7, 0x18, 0x1f, 0x95, 0xb1, 0x6a, 0xb9, 0x7c, 0x92,
    0xb3, 0x41, 0xc0, 0x02, 0x14, 0x41, 0xe2, 0x34, 0x5f, 0x1f, 0x56,
    0xdf, 0x24, 0x58, 0xf4, 0x26, 0xd1, 0x55, 0xb4, 0xba, 0x2d, 0xb6,
    0xdc, 0xd8, 0xc8, 0x00,
};

/* fips_sig_lengths is fips_sig with a non-minimally encoded length. */
static const uint8_t fips_sig_bad_length[] = {
    0x30, 0x81, 0x2d, 0x02, 0x15, 0x00, 0x8b, 0xac, 0x1a, 0xb6, 0x64,
    0x10, 0x43, 0x5c, 0xb7, 0x18, 0x1f, 0x95, 0xb1, 0x6a, 0xb9, 0x7c,
    0x92, 0xb3, 0x41, 0xc0, 0x02, 0x14, 0x41, 0xe2, 0x34, 0x5f, 0x1f,
    0x56, 0xdf, 0x24, 0x58, 0xf4, 0x26, 0xd1, 0x55, 0xb4, 0xba, 0x2d,
    0xb6, 0xdc, 0xd8, 0xc8, 0x00,
};

/* fips_sig_bad_r is fips_sig with a bad r value. */
static const uint8_t fips_sig_bad_r[] = {
    0x30, 0x2d, 0x02, 0x15, 0x00, 0x8c, 0xac, 0x1a, 0xb6, 0x64, 0x10,
    0x43, 0x5c, 0xb7, 0x18, 0x1f, 0x95, 0xb1, 0x6a, 0xb9, 0x7c, 0x92,
    0xb3, 0x41, 0xc0, 0x02, 0x14, 0x41, 0xe2, 0x34, 0x5f, 0x1f, 0x56,
    0xdf, 0x24, 0x58, 0xf4, 0x26, 0xd1, 0x55, 0xb4, 0xba, 0x2d, 0xb6,
    0xdc, 0xd8, 0xc8,
};

static DSA *get_fips_dsa(void) {
  DSA *dsa = DSA_new();
  if (!dsa) {
    return NULL;
  }
  dsa->p = BN_bin2bn(fips_p, sizeof(fips_p), NULL);
  dsa->q = BN_bin2bn(fips_q, sizeof(fips_q), NULL);
  dsa->g = BN_bin2bn(fips_g, sizeof(fips_g), NULL);
  dsa->pub_key = BN_bin2bn(fips_y, sizeof(fips_y), NULL);
  dsa->priv_key = BN_bin2bn(fips_x, sizeof(fips_x), NULL);
  if (dsa->p == NULL || dsa->q == NULL || dsa->g == NULL ||
      dsa->pub_key == NULL || dsa->priv_key == NULL) {
    DSA_free(dsa);
    return NULL;
  }
  return dsa;
}

static int test_generate(FILE *out) {
  BN_GENCB cb;
  DSA *dsa = NULL;
  int counter, ok = 0, i, j;
  uint8_t buf[256];
  unsigned long h;
  uint8_t sig[256];
  unsigned int siglen;

  fprintf(out, "test generation of DSA parameters\n");

  BN_GENCB_set(&cb, dsa_cb, out);
  dsa = DSA_new();
  if (dsa == NULL ||
      !DSA_generate_parameters_ex(dsa, 512, seed, 20, &counter, &h, &cb)) {
    goto end;
  }

  fprintf(out, "seed\n");
  for (i = 0; i < 20; i += 4) {
    fprintf(out, "%02X%02X%02X%02X ", seed[i], seed[i + 1], seed[i + 2],
            seed[i + 3]);
  }
  fprintf(out, "\ncounter=%d h=%ld\n", counter, h);

  if (counter != 105) {
    fprintf(stderr, "counter should be 105\n");
    goto end;
  }
  if (h != 2) {
    fprintf(stderr, "h should be 2\n");
    goto end;
  }

  i = BN_bn2bin(dsa->q, buf);
  j = sizeof(fips_q);
  if (i != j || memcmp(buf, fips_q, i) != 0) {
    fprintf(stderr, "q value is wrong\n");
    goto end;
  }

  i = BN_bn2bin(dsa->p, buf);
  j = sizeof(fips_p);
  if (i != j || memcmp(buf, fips_p, i) != 0) {
    fprintf(stderr, "p value is wrong\n");
    goto end;
  }

  i = BN_bn2bin(dsa->g, buf);
  j = sizeof(fips_g);
  if (i != j || memcmp(buf, fips_g, i) != 0) {
    fprintf(stderr, "g value is wrong\n");
    goto end;
  }

  DSA_generate_key(dsa);
  DSA_sign(0, fips_digest, sizeof(fips_digest), sig, &siglen, dsa);
  if (DSA_verify(0, fips_digest, sizeof(fips_digest), sig, siglen, dsa) == 1) {
    ok = 1;
  } else {
    fprintf(stderr, "verification failure\n");
  }

end:
  DSA_free(dsa);

  return ok;
}

static int test_verify(const uint8_t *sig, size_t sig_len, int expect) {
  int ok = 0;
  DSA *dsa = get_fips_dsa();
  if (dsa == NULL) {
    goto end;
  }

  int ret = DSA_verify(0, fips_digest, sizeof(fips_digest), sig, sig_len, dsa);
  if (ret != expect) {
    fprintf(stderr, "DSA_verify returned %d, want %d\n", ret, expect);
    goto end;
  }
  ok = 1;
  /* Clear any errorrs from a test with expected failure. */
  ERR_clear_error();

end:
  DSA_free(dsa);

  return ok;
}

int main(int argc, char **argv) {
  CRYPTO_library_init();

  if (!test_generate(stdout) ||
      !test_verify(fips_sig, sizeof(fips_sig), 1) ||
      !test_verify(fips_sig_negative, sizeof(fips_sig_negative), -1) ||
      !test_verify(fips_sig_extra, sizeof(fips_sig_extra), -1) ||
      !test_verify(fips_sig_bad_length, sizeof(fips_sig_bad_length), -1) ||
      !test_verify(fips_sig_bad_r, sizeof(fips_sig_bad_r), 0)) {
    ERR_print_errors_fp(stderr);
    return 1;
  }

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

static int dsa_cb(int p, int n, BN_GENCB *arg) {
  char c = '*';
  static int ok = 0, num = 0;

  switch (p) {
  case 0:
    c = '.';
    num++;
    break;
  case 1:
    c = '+';
    break;
  case 2:
    c = '*';
    ok++;
    break;
  case 3:
    c = '\n';
  }

  fputc(c, arg->arg);
  fflush(arg->arg);

  if (!ok && p == 0 && num > 1) {
    fprintf(stderr, "error in dsatest\n");
    return 0;
  }

  return 1;
}