text: /*
   * Copyright 2019 The OpenSSL Project Authors. All Rights Reserved.
   *
   * Licensed under the OpenSSL license (the "License").  You may not use
   * this file except in compliance with the License.  You can obtain a copy
   * in the file LICENSE in the source distribution or at
   * https://www.openssl.org/source/license.html
   */
  
  #include <string.h>
  
  #include "apps.h"
  #include "progs.h"
  #include <openssl/bio.h>
  #include <openssl/err.h>
  #include <openssl/evp.h>
  #include <openssl/kdf.h>
  #include <openssl/params.h>
  
  typedef enum OPTION_choice {
      OPT_ERR = -1, OPT_EOF = 0, OPT_HELP,
      OPT_KDFOPT, OPT_BIN, OPT_KEYLEN, OPT_OUT
  } OPTION_CHOICE;
  
  const OPTIONS kdf_options[] = {
      {OPT_HELP_STR, 1, '-', "Usage: %s [options] kdf_name\n"},
  
      OPT_SECTION("General"),
      {"help", OPT_HELP, '-', "Display this summary"},
      {"kdfopt", OPT_KDFOPT, 's', "KDF algorithm control parameters in n:v form"},
      {OPT_MORE_STR, 1, '-', "See 'Supported Controls' in the EVP_KDF_ docs\n"},
      {"keylen", OPT_KEYLEN, 's', "The size of the output derived key"},
  
      OPT_SECTION("Output"),
      {"out", OPT_OUT, '>', "Output to filename rather than stdout"},
      {"binary", OPT_BIN, '-',
          "Output in binary format (default is hexadecimal)"},
  
      OPT_PARAMETERS(),
      {"kdf_name", 0, 0, "Name of the KDF algorithm"},
      {NULL}
  };
  
  int kdf_main(int argc, char **argv)
  {
      int ret = 1, out_bin = 0;
      OPTION_CHOICE o;
      STACK_OF(OPENSSL_STRING) *opts = NULL;
      char *prog, *hexout = NULL;
      const char *outfile = NULL;
      unsigned char *dkm_bytes = NULL;
      size_t dkm_len = 0;
      BIO *out = NULL;
      EVP_KDF *kdf = NULL;
      EVP_KDF_CTX *ctx = NULL;
  
      prog = opt_init(argc, argv, kdf_options);
      while ((o = opt_next()) != OPT_EOF) {
          switch (o) {
          default:
  opthelp:
              BIO_printf(bio_err, "%s: Use -help for summary.\n", prog);
              goto err;
          case OPT_HELP:
              opt_help(kdf_options);
              ret = 0;
              goto err;
          case OPT_BIN:
              out_bin = 1;
              break;
          case OPT_KEYLEN:
              dkm_len = (size_t)atoi(opt_arg());
              break;
          case OPT_OUT:
              outfile = opt_arg();
              break;
          case OPT_KDFOPT:
              if (opts == NULL)
                  opts = sk_OPENSSL_STRING_new_null();
              if (opts == NULL || !sk_OPENSSL_STRING_push(opts, opt_arg()))
                  goto opthelp;
              break;
          }
      }
      argc = opt_num_rest();
      argv = opt_rest();
  
      if (argc != 1) {
          BIO_printf(bio_err, "Invalid number of extra arguments\n");
          goto opthelp;
      }
  
      if ((kdf = EVP_KDF_fetch(NULL, argv[0], NULL)) == NULL) {
          BIO_printf(bio_err, "Invalid KDF name %s\n", argv[0]);
          goto opthelp;
      }
  
      ctx = EVP_KDF_CTX_new(kdf);
      if (ctx == NULL)
          goto err;
  
      if (opts != NULL) {
          int ok = 1;
          OSSL_PARAM *params =
              app_params_new_from_opts(opts, EVP_KDF_settable_ctx_params(kdf));
  
          if (params == NULL)
              goto err;
  
          if (!EVP_KDF_CTX_set_params(ctx, params)) {
              BIO_printf(bio_err, "KDF parameter error\n");
              ERR_print_errors(bio_err);
              ok = 0;
          }
          app_params_free(params);
          if (!ok)
              goto err;
      }
  
      out = bio_open_default(outfile, 'w', out_bin ? FORMAT_BINARY : FORMAT_TEXT);
      if (out == NULL)
          goto err;
  
      if (dkm_len <= 0) {
          BIO_printf(bio_err, "Invalid derived key length.\n");
          goto err;
      }
      dkm_bytes = app_malloc(dkm_len, "out buffer");
      if (dkm_bytes == NULL)
          goto err;
  
      if (!EVP_KDF_derive(ctx, dkm_bytes, dkm_len)) {
          BIO_printf(bio_err, "EVP_KDF_derive failed\n");
          goto err;
      }
  
      if (out_bin) {
          BIO_write(out, dkm_bytes, dkm_len);
      } else {
          hexout = OPENSSL_buf2hexstr(dkm_bytes, dkm_len);
          BIO_printf(out, "%s\n\n", hexout);
      }
  
      ret = 0;
  err:
      if (ret != 0)
          ERR_print_errors(bio_err);
      OPENSSL_clear_free(dkm_bytes, dkm_len);
      sk_OPENSSL_STRING_free(opts);
      EVP_KDF_free(kdf);
      EVP_KDF_CTX_free(ctx);
      BIO_free(out);
      OPENSSL_free(hexout);
      return ret;
  }
  