// SPDX-License-Identifier: Apache-2.0 and Unknown

/*
NIST-developed software is provided by NIST as a public service. You may use,
copy, and distribute copies of the software in any medium, provided that you
keep intact this entire notice. You may improve, modify, and create derivative
works of the software or any portion of the software, and you may copy and
distribute such modifications or works. Modified works should carry a notice
stating that you changed the software and should note the date and nature of any
such change. Please explicitly acknowledge the National Institute of Standards
and Technology as the source of the software.

NIST-developed software is expressly provided "AS IS." NIST MAKES NO WARRANTY OF
ANY KIND, EXPRESS, IMPLIED, IN FACT, OR ARISING BY OPERATION OF LAW, INCLUDING,
WITHOUT LIMITATION, THE IMPLIED WARRANTY OF MERCHANTABILITY, FITNESS FOR A
PARTICULAR PURPOSE, NON-INFRINGEMENT, AND DATA ACCURACY. NIST NEITHER REPRESENTS
NOR WARRANTS THAT THE OPERATION OF THE SOFTWARE WILL BE UNINTERRUPTED OR
ERROR-FREE, OR THAT ANY DEFECTS WILL BE CORRECTED. NIST DOES NOT WARRANT OR MAKE
ANY REPRESENTATIONS REGARDING THE USE OF THE SOFTWARE OR THE RESULTS THEREOF,
INCLUDING BUT NOT LIMITED TO THE CORRECTNESS, ACCURACY, RELIABILITY, OR
USEFULNESS OF THE SOFTWARE.

You are solely responsible for determining the appropriateness of using and
distributing the software and you assume all risks associated with its use,
including but not limited to the risks and costs of program errors, compliance
with applicable laws, damage to or loss of data, programs or equipment, and the
unavailability or interruption of operation. This software is not intended to be
used in any situation where a failure could cause risk of injury or damage to
property. The software developed by NIST employees is not subject to copyright
protection within the United States.
*/

#include "api.h"
#include "rng.h"
#include <ctype.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#define MAX_MARKER_LEN 50

#define KAT_SUCCESS 0
#define KAT_FILE_OPEN_ERROR -1
#define KAT_DATA_ERROR -3
#define KAT_CRYPTO_FAILURE -4

int FindMarker(FILE *infile, const char *marker);
int ReadHex(FILE *infile, unsigned char *A, int Length, char *str);
void fprintBstr(FILE *fp, char *S, unsigned char *A, unsigned long long L);

int main(void) {
  char fn_req[32], fn_rsp[32];
  FILE *fp_req, *fp_rsp;
  unsigned char seed[48];
  unsigned char msg[3300];
  unsigned char entropy_input[48];
  unsigned char *m, *sm, *m1;
  unsigned long long mlen, smlen, mlen1;
  int count;
  int done;
  unsigned char pk[CRYPTO_PUBLICKEYBYTES], sk[CRYPTO_SECRETKEYBYTES];
  int ret_val;

  // Create the REQUEST file
  sprintf(fn_req, "PQCsignKAT_%d_%s.req", CRYPTO_SECRETKEYBYTES,
          CRYPTO_ALGNAME);
  if ((fp_req = fopen(fn_req, "w")) == NULL) {
    printf("Couldn't open <%s> for write\n", fn_req);
    return KAT_FILE_OPEN_ERROR;
  }
  sprintf(fn_rsp, "PQCsignKAT_%d_%s.rsp", CRYPTO_SECRETKEYBYTES,
          CRYPTO_ALGNAME);
  if ((fp_rsp = fopen(fn_rsp, "w")) == NULL) {
    printf("Couldn't open <%s> for write\n", fn_rsp);
    return KAT_FILE_OPEN_ERROR;
  }

  for (int i = 0; i < 48; i++)
    entropy_input[i] = i;

  randombytes_init(entropy_input, NULL, 256);
  for (int i = 0; i < 100; i++) {
    fprintf(fp_req, "count = %d\n", i);
    randombytes(seed, 48);
    fprintBstr(fp_req, "seed = ", seed, 48);
    mlen = 33 * (i + 1);
    fprintf(fp_req, "mlen = %llu\n", mlen);
    randombytes(msg, mlen);
    fprintBstr(fp_req, "msg = ", msg, mlen);
    fprintf(fp_req, "pk =\n");
    fprintf(fp_req, "sk =\n");
    fprintf(fp_req, "smlen =\n");
    fprintf(fp_req, "sm =\n\n");
  }
  fclose(fp_req);

  // Create the RESPONSE file based on what's in the REQUEST file
  if ((fp_req = fopen(fn_req, "r")) == NULL) {
    printf("Couldn't open <%s> for read\n", fn_req);
    return KAT_FILE_OPEN_ERROR;
  }

  fprintf(fp_rsp, "# %s\n\n", CRYPTO_ALGNAME);
  done = 0;
  do {
    if (FindMarker(fp_req, "count = ")) {
      if (fscanf(fp_req, "%d", &count) != 1)
        return KAT_DATA_ERROR;
    } else {
      done = 1;
      break;
    }
    fprintf(fp_rsp, "count = %d\n", count);

    if (!ReadHex(fp_req, seed, 48, "seed = ")) {
      printf("ERROR: unable to read 'seed' from <%s>\n", fn_req);
      return KAT_DATA_ERROR;
    }
    fprintBstr(fp_rsp, "seed = ", seed, 48);

    randombytes_init(seed, NULL, 256);

    if (FindMarker(fp_req, "mlen = ")) {
      if (fscanf(fp_req, "%llu", &mlen) != 1)
        return KAT_DATA_ERROR;
    } else {
      printf("ERROR: unable to read 'mlen' from <%s>\n", fn_req);
      return KAT_DATA_ERROR;
    }
    fprintf(fp_rsp, "mlen = %llu\n", mlen);

    m = (unsigned char *)calloc(mlen, sizeof(unsigned char));
    m1 = (unsigned char *)calloc(mlen + CRYPTO_BYTES, sizeof(unsigned char));
    sm = (unsigned char *)calloc(mlen + CRYPTO_BYTES, sizeof(unsigned char));

    if (!ReadHex(fp_req, m, (int)mlen, "msg = ")) {
      printf("ERROR: unable to read 'msg' from <%s>\n", fn_req);
      return KAT_DATA_ERROR;
    }
    fprintBstr(fp_rsp, "msg = ", m, mlen);

    // Generate the public/private keypair
    if ((ret_val = crypto_sign_keypair(pk, sk)) != 0) {
      printf("crypto_sign_keypair returned <%d>\n", ret_val);
      return KAT_CRYPTO_FAILURE;
    }
    fprintBstr(fp_rsp, "pk = ", pk, CRYPTO_PUBLICKEYBYTES);
    fprintBstr(fp_rsp, "sk = ", sk, CRYPTO_SECRETKEYBYTES);

    if ((ret_val = crypto_sign(sm, &smlen, m, mlen, sk)) != 0) {
      printf("crypto_sign returned <%d>\n", ret_val);
      return KAT_CRYPTO_FAILURE;
    }
    fprintf(fp_rsp, "smlen = %llu\n", smlen);
    fprintBstr(fp_rsp, "sm = ", sm, smlen);
    fprintf(fp_rsp, "\n");

    if ((ret_val = crypto_sign_open(m1, &mlen1, sm, smlen, pk)) != 0) {
      printf("crypto_sign_open returned <%d>\n", ret_val);
      return KAT_CRYPTO_FAILURE;
    }

    if (mlen != mlen1) {
      printf(
          "crypto_sign_open returned bad 'mlen': Got <%llu>, expected <%llu>\n",
          mlen1, mlen);
      return KAT_CRYPTO_FAILURE;
    }

    if (memcmp(m, m1, mlen)) {
      printf("crypto_sign_open returned bad 'm' value\n");
      return KAT_CRYPTO_FAILURE;
    }

    free(m);
    free(m1);
    free(sm);

  } while (!done);

  fclose(fp_req);
  fclose(fp_rsp);

  return KAT_SUCCESS;
}

//
// ALLOW TO READ HEXADECIMAL ENTRY (KEYS, DATA, TEXT, etc.)
//
int FindMarker(FILE *infile, const char *marker) {
  char line[MAX_MARKER_LEN];
  int i, len;
  int curr_line;

  len = (int)strlen(marker);
  if (len > MAX_MARKER_LEN - 1)
    len = MAX_MARKER_LEN - 1;

  for (i = 0; i < len; i++) {
    curr_line = fgetc(infile);
    line[i] = curr_line;
    if (curr_line == EOF)
      return 0;
  }
  line[len] = '\0';

  while (1) {
    if (!strncmp(line, marker, len))
      return 1;

    for (i = 0; i < len - 1; i++)
      line[i] = line[i + 1];
    curr_line = fgetc(infile);
    line[len - 1] = curr_line;
    if (curr_line == EOF)
      return 0;
    line[len] = '\0';
  }

  // shouldn't get here
  return 0;
}

//
// ALLOW TO READ HEXADECIMAL ENTRY (KEYS, DATA, TEXT, etc.)
//
int ReadHex(FILE *infile, unsigned char *A, int Length, char *str) {
  int i, ch, started;
  unsigned char ich;

  if (Length == 0) {
    A[0] = 0x00;
    return 1;
  }
  memset(A, 0x00, Length);
  started = 0;
  if (FindMarker(infile, str))
    while ((ch = fgetc(infile)) != EOF) {
      if (!isxdigit(ch)) {
        if (!started) {
          if (ch == '\n')
            break;
          else
            continue;
        } else
          break;
      }
      started = 1;
      if ((ch >= '0') && (ch <= '9'))
        ich = ch - '0';
      else if ((ch >= 'A') && (ch <= 'F'))
        ich = ch - 'A' + 10;
      else if ((ch >= 'a') && (ch <= 'f'))
        ich = ch - 'a' + 10;
      else // shouldn't ever get here
        ich = 0;

      for (i = 0; i < Length - 1; i++)
        A[i] = (A[i] << 4) | (A[i + 1] >> 4);
      A[Length - 1] = (A[Length - 1] << 4) | ich;
    }
  else
    return 0;

  return 1;
}

void fprintBstr(FILE *fp, char *S, unsigned char *A, unsigned long long L) {
  unsigned long long i;

  fprintf(fp, "%s", S);

  for (i = 0; i < L; i++)
    fprintf(fp, "%02X", A[i]);

  if (L == 0)
    fprintf(fp, "00");

  fprintf(fp, "\n");
}
