/* apps/dhparam.c */
/* 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.]
 */
/* ====================================================================
 * Copyright (c) 1998-2000 The OpenSSL Project.  All rights reserved.
 *
 * 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 above 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 acknowledgment:
 *    "This product includes software developed by the OpenSSL Project
 *    for use in the OpenSSL Toolkit. (http://www.openssl.org/)"
 *
 * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to
 *    endorse or promote products derived from this software without
 *    prior written permission. For written permission, please contact
 *    openssl-core@openssl.org.
 *
 * 5. Products derived from this software may not be called "OpenSSL"
 *    nor may "OpenSSL" appear in their names without prior written
 *    permission of the OpenSSL Project.
 *
 * 6. Redistributions of any form whatsoever must retain the following
 *    acknowledgment:
 *    "This product includes software developed by the OpenSSL Project
 *    for use in the OpenSSL Toolkit (http://www.openssl.org/)"
 *
 * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY
 * EXPRESSED 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 OpenSSL PROJECT OR
 * ITS 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.
 * ====================================================================
 *
 * This product includes cryptographic software written by Eric Young
 * (eay@cryptsoft.com).  This product includes software written by Tim
 * Hudson (tjh@cryptsoft.com).
 *
 */

#include <openssl/opensslconf.h> /* for OPENSSL_NO_DH */
#ifndef OPENSSL_NO_DH
# include <stdio.h>
# include <stdlib.h>
# include <time.h>
# include <string.h>
# include "apps.h"
# include <openssl/bio.h>
# include <openssl/err.h>
# include <openssl/bn.h>
# include <openssl/dh.h>
# include <openssl/x509.h>
# include <openssl/pem.h>

# ifndef OPENSSL_NO_DSA
#  include <openssl/dsa.h>
# endif

# undef PROG
# define PROG    dhparam_main

# define DEFBITS 2048

/*-
 * -inform arg  - input format - default PEM (DER or PEM)
 * -outform arg - output format - default PEM
 * -in arg      - input file - default stdin
 * -out arg     - output file - default stdout
 * -dsaparam  - read or generate DSA parameters, convert to DH
 * -check       - check the parameters are ok
 * -noout
 * -text
 * -C
 */

static int dh_cb(int p, int n, BN_GENCB *cb);

int MAIN(int, char **);

int MAIN(int argc, char **argv)
{
    DH *dh = NULL;
    int i, badops = 0, text = 0;
# ifndef OPENSSL_NO_DSA
    int dsaparam = 0;
# endif
    BIO *in = NULL, *out = NULL;
    int informat, outformat, check = 0, noout = 0, C = 0, ret = 1;
    char *infile, *outfile, *prog;
    char *inrand = NULL;
# ifndef OPENSSL_NO_ENGINE
    char *engine = NULL;
# endif
    int num = 0, g = 0;

    apps_startup();

    if (bio_err == NULL)
        if ((bio_err = BIO_new(BIO_s_file())) != NULL)
            BIO_set_fp(bio_err, stderr, BIO_NOCLOSE | BIO_FP_TEXT);

    if (!load_config(bio_err, NULL))
        goto end;

    infile = NULL;
    outfile = NULL;
    informat = FORMAT_PEM;
    outformat = FORMAT_PEM;

    prog = argv[0];
    argc--;
    argv++;
    while (argc >= 1) {
        if (strcmp(*argv, "-inform") == 0) {
            if (--argc < 1)
                goto bad;
            informat = str2fmt(*(++argv));
        } else if (strcmp(*argv, "-outform") == 0) {
            if (--argc < 1)
                goto bad;
            outformat = str2fmt(*(++argv));
        } else if (strcmp(*argv, "-in") == 0) {
            if (--argc < 1)
                goto bad;
            infile = *(++argv);
        } else if (strcmp(*argv, "-out") == 0) {
            if (--argc < 1)
                goto bad;
            outfile = *(++argv);
        }
# ifndef OPENSSL_NO_ENGINE
        else if (strcmp(*argv, "-engine") == 0) {
            if (--argc < 1)
                goto bad;
            engine = *(++argv);
        }
# endif
        else if (strcmp(*argv, "-check") == 0)
            check = 1;
        else if (strcmp(*argv, "-text") == 0)
            text = 1;
# ifndef OPENSSL_NO_DSA
        else if (strcmp(*argv, "-dsaparam") == 0)
            dsaparam = 1;
# endif
        else if (strcmp(*argv, "-C") == 0)
            C = 1;
        else if (strcmp(*argv, "-noout") == 0)
            noout = 1;
        else if (strcmp(*argv, "-2") == 0)
            g = 2;
        else if (strcmp(*argv, "-5") == 0)
            g = 5;
        else if (strcmp(*argv, "-rand") == 0) {
            if (--argc < 1)
                goto bad;
            inrand = *(++argv);
        } else if (((sscanf(*argv, "%d", &num) == 0) || (num <= 0)))
            goto bad;
        argv++;
        argc--;
    }

    if (badops) {
 bad:
        BIO_printf(bio_err, "%s [options] [numbits]\n", prog);
        BIO_printf(bio_err, "where options are\n");
        BIO_printf(bio_err, " -inform arg   input format - one of DER PEM\n");
        BIO_printf(bio_err,
                   " -outform arg  output format - one of DER PEM\n");
        BIO_printf(bio_err, " -in arg       input file\n");
        BIO_printf(bio_err, " -out arg      output file\n");
# ifndef OPENSSL_NO_DSA
        BIO_printf(bio_err,
                   " -dsaparam     read or generate DSA parameters, convert to DH\n");
# endif
        BIO_printf(bio_err, " -check        check the DH parameters\n");
        BIO_printf(bio_err,
                   " -text         print a text form of the DH parameters\n");
        BIO_printf(bio_err, " -C            Output C code\n");
        BIO_printf(bio_err,
                   " -2            generate parameters using  2 as the generator value\n");
        BIO_printf(bio_err,
                   " -5            generate parameters using  5 as the generator value\n");
        BIO_printf(bio_err,
                   " numbits       number of bits in to generate (default 2048)\n");
# ifndef OPENSSL_NO_ENGINE
        BIO_printf(bio_err,
                   " -engine e     use engine e, possibly a hardware device.\n");
# endif
        BIO_printf(bio_err, " -rand file%cfile%c...\n", LIST_SEPARATOR_CHAR,
                   LIST_SEPARATOR_CHAR);
        BIO_printf(bio_err,
                   "               - load the file (or the files in the directory) into\n");
        BIO_printf(bio_err, "               the random number generator\n");
        BIO_printf(bio_err, " -noout        no output\n");
        goto end;
    }

    ERR_load_crypto_strings();

# ifndef OPENSSL_NO_ENGINE
    setup_engine(bio_err, engine, 0);
# endif

    if (g && !num)
        num = DEFBITS;

# ifndef OPENSSL_NO_DSA
    if (dsaparam) {
        if (g) {
            BIO_printf(bio_err,
                       "generator may not be chosen for DSA parameters\n");
            goto end;
        }
    } else
# endif
    {
        /* DH parameters */
        if (num && !g)
            g = 2;
    }

    if (num) {

        BN_GENCB *cb;
        cb = BN_GENCB_new();
        if (!cb) {
            ERR_print_errors(bio_err);
            goto end;
        }

        BN_GENCB_set(cb, dh_cb, bio_err);
        if (!app_RAND_load_file(NULL, bio_err, 1) && inrand == NULL) {
            BIO_printf(bio_err,
                       "warning, not much extra random data, consider using the -rand option\n");
        }
        if (inrand != NULL)
            BIO_printf(bio_err, "%ld semi-random bytes loaded\n",
                       app_RAND_load_files(inrand));

# ifndef OPENSSL_NO_DSA
        if (dsaparam) {
            DSA *dsa = DSA_new();

            BIO_printf(bio_err,
                       "Generating DSA parameters, %d bit long prime\n", num);
            if (!dsa
                || !DSA_generate_parameters_ex(dsa, num, NULL, 0, NULL, NULL,
                                               cb)) {
                if (dsa)
                    DSA_free(dsa);
                BN_GENCB_free(cb);
                ERR_print_errors(bio_err);
                goto end;
            }

            dh = DSA_dup_DH(dsa);
            DSA_free(dsa);
            if (dh == NULL) {
                BN_GENCB_free(cb);
                ERR_print_errors(bio_err);
                goto end;
            }
        } else
# endif
        {
            dh = DH_new();
            BIO_printf(bio_err,
                       "Generating DH parameters, %d bit long safe prime, generator %d\n",
                       num, g);
            BIO_printf(bio_err, "This is going to take a long time\n");
            if (!dh || !DH_generate_parameters_ex(dh, num, g, cb)) {
                BN_GENCB_free(cb);
                ERR_print_errors(bio_err);
                goto end;
            }
        }

        BN_GENCB_free(cb);
        app_RAND_write_file(NULL, bio_err);
    } else {

        in = BIO_new(BIO_s_file());
        if (in == NULL) {
            ERR_print_errors(bio_err);
            goto end;
        }
        if (infile == NULL)
            BIO_set_fp(in, stdin, BIO_NOCLOSE);
        else {
            if (BIO_read_filename(in, infile) <= 0) {
                perror(infile);
                goto end;
            }
        }

        if (informat != FORMAT_ASN1 && informat != FORMAT_PEM) {
            BIO_printf(bio_err, "bad input format specified\n");
            goto end;
        }
# ifndef OPENSSL_NO_DSA
        if (dsaparam) {
            DSA *dsa;

            if (informat == FORMAT_ASN1)
                dsa = d2i_DSAparams_bio(in, NULL);
            else                /* informat == FORMAT_PEM */
                dsa = PEM_read_bio_DSAparams(in, NULL, NULL, NULL);

            if (dsa == NULL) {
                BIO_printf(bio_err, "unable to load DSA parameters\n");
                ERR_print_errors(bio_err);
                goto end;
            }

            dh = DSA_dup_DH(dsa);
            DSA_free(dsa);
            if (dh == NULL) {
                ERR_print_errors(bio_err);
                goto end;
            }
        } else
# endif
        {
            if (informat == FORMAT_ASN1)
                dh = d2i_DHparams_bio(in, NULL);
            else                /* informat == FORMAT_PEM */
                dh = PEM_read_bio_DHparams(in, NULL, NULL, NULL);

            if (dh == NULL) {
                BIO_printf(bio_err, "unable to load DH parameters\n");
                ERR_print_errors(bio_err);
                goto end;
            }
        }

        /* dh != NULL */
    }

    out = BIO_new(BIO_s_file());
    if (out == NULL) {
        ERR_print_errors(bio_err);
        goto end;
    }
    if (outfile == NULL) {
        BIO_set_fp(out, stdout, BIO_NOCLOSE);
# ifdef OPENSSL_SYS_VMS
        {
            BIO *tmpbio = BIO_new(BIO_f_linebuffer());
            out = BIO_push(tmpbio, out);
        }
# endif
    } else {
        if (BIO_write_filename(out, outfile) <= 0) {
            perror(outfile);
            goto end;
        }
    }

    if (text) {
        DHparams_print(out, dh);
    }

    if (check) {
        if (!DH_check(dh, &i)) {
            ERR_print_errors(bio_err);
            goto end;
        }
        if (i & DH_CHECK_P_NOT_PRIME)
            printf("p value is not prime\n");
        if (i & DH_CHECK_P_NOT_SAFE_PRIME)
            printf("p value is not a safe prime\n");
        if (i & DH_UNABLE_TO_CHECK_GENERATOR)
            printf("unable to check the generator value\n");
        if (i & DH_NOT_SUITABLE_GENERATOR)
            printf("the g value is not a generator\n");
        if (i == 0)
            printf("DH parameters appear to be ok.\n");
    }
    if (C) {
        unsigned char *data;
        int len, l, bits;

        len = BN_num_bytes(dh->p);
        bits = BN_num_bits(dh->p);
        data = (unsigned char *)OPENSSL_malloc(len);
        if (data == NULL) {
            perror("OPENSSL_malloc");
            goto end;
        }
        printf("#ifndef HEADER_DH_H\n"
               "#include <openssl/dh.h>\n" "#endif\n");
        printf("DH *get_dh%d()\n\t{\n", bits);

        l = BN_bn2bin(dh->p, data);
        printf("\tstatic unsigned char dh%d_p[]={", bits);
        for (i = 0; i < l; i++) {
            if ((i % 12) == 0)
                printf("\n\t\t");
            printf("0x%02X,", data[i]);
        }
        printf("\n\t\t};\n");

        l = BN_bn2bin(dh->g, data);
        printf("\tstatic unsigned char dh%d_g[]={", bits);
        for (i = 0; i < l; i++) {
            if ((i % 12) == 0)
                printf("\n\t\t");
            printf("0x%02X,", data[i]);
        }
        printf("\n\t\t};\n");

        printf("\tDH *dh;\n\n");
        printf("\tif ((dh=DH_new()) == NULL) return(NULL);\n");
        printf("\tdh->p=BN_bin2bn(dh%d_p,sizeof(dh%d_p),NULL);\n",
               bits, bits);
        printf("\tdh->g=BN_bin2bn(dh%d_g,sizeof(dh%d_g),NULL);\n",
               bits, bits);
        printf("\tif ((dh->p == NULL) || (dh->g == NULL))\n");
        printf("\t\t{ DH_free(dh); return(NULL); }\n");
        if (dh->length)
            printf("\tdh->length = %ld;\n", dh->length);
        printf("\treturn(dh);\n\t}\n");
        OPENSSL_free(data);
    }

    if (!noout) {
        if (outformat == FORMAT_ASN1)
            i = i2d_DHparams_bio(out, dh);
        else if (outformat == FORMAT_PEM) {
            if (dh->q)
                i = PEM_write_bio_DHxparams(out, dh);
            else
                i = PEM_write_bio_DHparams(out, dh);
        } else {
            BIO_printf(bio_err, "bad output format specified for outfile\n");
            goto end;
        }
        if (!i) {
            BIO_printf(bio_err, "unable to write DH parameters\n");
            ERR_print_errors(bio_err);
            goto end;
        }
    }
    ret = 0;
 end:
    if (in != NULL)
        BIO_free(in);
    if (out != NULL)
        BIO_free_all(out);
    if (dh != NULL)
        DH_free(dh);
    apps_shutdown();
    OPENSSL_EXIT(ret);
}

/* dh_cb is identical to dsa_cb in apps/dsaparam.c */
static int dh_cb(int p, int n, BN_GENCB *cb)
{
    char c = '*';

    if (p == 0)
        c = '.';
    if (p == 1)
        c = '+';
    if (p == 2)
        c = '*';
    if (p == 3)
        c = '\n';
    BIO_write(BN_GENCB_get_arg(cb), &c, 1);
    (void)BIO_flush(BN_GENCB_get_arg(cb));
    return 1;
}

#else                           /* !OPENSSL_NO_DH */

# if PEDANTIC
static void *dummy = &dummy;
# endif

#endif