/* $OpenBSD: ecparam.c,v 1.21 2021/05/10 20:58:32 tb Exp $ */
/*
 * Written by Nils Larsch for the OpenSSL project.
 */
/* ====================================================================
 * Copyright (c) 1998-2005 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).
 *
 */
/* ====================================================================
 * Copyright 2002 Sun Microsystems, Inc. ALL RIGHTS RESERVED.
 *
 * Portions of the attached software ("Contribution") are developed by
 * SUN MICROSYSTEMS, INC., and are contributed to the OpenSSL project.
 *
 * The Contribution is licensed pursuant to the OpenSSL open source
 * license provided above.
 *
 * The elliptic curve binary polynomial software is originally written by
 * Sheueling Chang Shantz and Douglas Stebila of Sun Microsystems Laboratories.
 *
 */

#include <openssl/opensslconf.h>

#ifndef OPENSSL_NO_EC

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

#include "apps.h"

#include <openssl/bio.h>
#include <openssl/bn.h>
#include <openssl/ec.h>
#include <openssl/err.h>
#include <openssl/pem.h>
#include <openssl/x509.h>

static int ecparam_print_var(BIO *, BIGNUM *, const char *, int,
    unsigned char *);

static struct {
        int C;
        int asn1_flag;
        int check;
        char *curve_name;
        point_conversion_form_t form;
        int genkey;
        char *infile;
        int informat;
        int list_curves;
        int new_asn1_flag;
        int new_form;
        int no_seed;
        int noout;
        char *outfile;
        int outformat;
        int text;
} ecparam_config;

static int
ecparam_opt_form(char *arg)
{
        if (strcmp(arg, "compressed") == 0)
                ecparam_config.form = POINT_CONVERSION_COMPRESSED;
        else if (strcmp(arg, "uncompressed") == 0)
                ecparam_config.form = POINT_CONVERSION_UNCOMPRESSED;
        else if (strcmp(arg, "hybrid") == 0)
                ecparam_config.form = POINT_CONVERSION_HYBRID;
        else
                return (1);

        ecparam_config.new_form = 1;
        return (0);
}

static int
ecparam_opt_enctype(char *arg)
{
        if (strcmp(arg, "explicit") == 0)
                ecparam_config.asn1_flag = 0;
        else if (strcmp(arg, "named_curve") == 0)
                ecparam_config.asn1_flag = OPENSSL_EC_NAMED_CURVE;
        else
                return (1);

        ecparam_config.new_asn1_flag = 1;
        return (0);
}

static const struct option ecparam_options[] = {
        {
                .name = "C",
                .desc = "Convert the EC parameters into C code",
                .type = OPTION_FLAG,
                .opt.flag = &ecparam_config.C,
        },
        {
                .name = "check",
                .desc = "Validate the elliptic curve parameters",
                .type = OPTION_FLAG,
                .opt.flag = &ecparam_config.check,
        },
        {
                .name = "conv_form",
                .argname = "form",
                .desc = "Specify point conversion form:\n"
                    "  compressed, uncompressed (default), hybrid",
                .type = OPTION_ARG_FUNC,
                .opt.argfunc = ecparam_opt_form,
        },
        {
                .name = "genkey",
                .desc = "Generate an EC private key using the specified "
                    "parameters",
                .type = OPTION_FLAG,
                .opt.flag = &ecparam_config.genkey,
        },
        {
                .name = "in",
                .argname = "file",
                .desc = "Input file to read parameters from (default stdin)",
                .type = OPTION_ARG,
                .opt.arg = &ecparam_config.infile,
        },
        {
                .name = "inform",
                .argname = "format",
                .desc = "Input format (DER or PEM)",
                .type = OPTION_ARG_FORMAT,
                .opt.value = &ecparam_config.informat,
        },
        {
                .name = "list_curves",
                .desc = "Print list of all currently implemented EC "
                    "parameter names",
                .type = OPTION_FLAG,
                .opt.flag = &ecparam_config.list_curves,
        },
        {
                .name = "name",
                .argname = "curve",
                .desc = "Use the EC parameters with the specified name",
                .type = OPTION_ARG,
                .opt.arg = &ecparam_config.curve_name,
        },
        {
                .name = "no_seed",
                .desc = "Do not output seed with explicit parameter encoding",
                .type = OPTION_FLAG,
                .opt.flag = &ecparam_config.no_seed,
        },
        {
                .name = "noout",
                .desc = "Do not output encoded version of EC parameters",
                .type = OPTION_FLAG,
                .opt.flag = &ecparam_config.noout,
        },
        {
                .name = "out",
                .argname = "file",
                .desc = "Output file to write parameters to (default stdout)",
                .type = OPTION_ARG,
                .opt.arg = &ecparam_config.outfile,
        },
        {
                .name = "outform",
                .argname = "format",
                .desc = "Output format (DER or PEM)",
                .type = OPTION_ARG_FORMAT,
                .opt.value = &ecparam_config.outformat,
        },
        {
                .name = "param_enc",
                .argname = "type",
                .desc = "Specify EC parameter ASN.1 encoding type:\n"
                    "  explicit, named_curve (default)",
                .type = OPTION_ARG_FUNC,
                .opt.argfunc = ecparam_opt_enctype,
        },
        {
                .name = "text",
                .desc = "Print out the EC parameters in human readable form",
                .type = OPTION_FLAG,
                .opt.flag = &ecparam_config.text,
        },
        {NULL},
};

static void
ecparam_usage(void)
{
        fprintf(stderr, "usage: ecparam [-C] [-check] [-conv_form arg] "
            " [-genkey]\n"
            "    [-in file] [-inform DER | PEM] [-list_curves] [-name arg]\n"
            "    [-no_seed] [-noout] [-out file] [-outform DER | PEM]\n"
            "    [-param_enc arg] [-text]\n\n");
        options_usage(ecparam_options);
}

int
ecparam_main(int argc, char **argv)
{
        BIGNUM *ec_p = NULL, *ec_a = NULL, *ec_b = NULL, *ec_gen = NULL;
        BIGNUM *ec_order = NULL, *ec_cofactor = NULL;
        EC_GROUP *group = NULL;
        unsigned char *buffer = NULL;
        BIO *in = NULL, *out = NULL;
        int i, ret = 1;

        if (single_execution) {
                if (pledge("stdio cpath wpath rpath", NULL) == -1) {
                        perror("pledge");
                        exit(1);
                }
        }

        memset(&ecparam_config, 0, sizeof(ecparam_config));
        ecparam_config.asn1_flag = OPENSSL_EC_NAMED_CURVE;
        ecparam_config.form = POINT_CONVERSION_UNCOMPRESSED;
        ecparam_config.informat = FORMAT_PEM;
        ecparam_config.outformat = FORMAT_PEM;

        if (options_parse(argc, argv, ecparam_options, NULL, NULL) != 0) {
                ecparam_usage();
                goto end;
        }

        in = BIO_new(BIO_s_file());
        out = BIO_new(BIO_s_file());
        if ((in == NULL) || (out == NULL)) {
                ERR_print_errors(bio_err);
                goto end;
        }
        if (ecparam_config.infile == NULL)
                BIO_set_fp(in, stdin, BIO_NOCLOSE);
        else {
                if (BIO_read_filename(in, ecparam_config.infile) <= 0) {
                        perror(ecparam_config.infile);
                        goto end;
                }
        }
        if (ecparam_config.outfile == NULL) {
                BIO_set_fp(out, stdout, BIO_NOCLOSE);
        } else {
                if (BIO_write_filename(out, ecparam_config.outfile) <= 0) {
                        perror(ecparam_config.outfile);
                        goto end;
                }
        }

        if (ecparam_config.list_curves) {
                EC_builtin_curve *curves = NULL;
                size_t crv_len = 0;
                size_t n = 0;

                crv_len = EC_get_builtin_curves(NULL, 0);

                curves = reallocarray(NULL, crv_len, sizeof(EC_builtin_curve));
                if (curves == NULL)
                        goto end;

                if (!EC_get_builtin_curves(curves, crv_len)) {
                        free(curves);
                        goto end;
                }
                for (n = 0; n < crv_len; n++) {
                        const char *comment;
                        const char *sname;
                        comment = curves[n].comment;
                        sname = OBJ_nid2sn(curves[n].nid);
                        if (comment == NULL)
                                comment = "CURVE DESCRIPTION NOT AVAILABLE";
                        if (sname == NULL)
                                sname = "";

                        BIO_printf(out, "  %-10s: ", sname);
                        BIO_printf(out, "%s\n", comment);
                }

                free(curves);
                ret = 0;
                goto end;
        }
        if (ecparam_config.curve_name != NULL) {
                int nid;

                /*
                 * workaround for the SECG curve names secp192r1 and
                 * secp256r1 (which are the same as the curves prime192v1 and
                 * prime256v1 defined in X9.62)
                 */
                if (!strcmp(ecparam_config.curve_name, "secp192r1")) {
                        BIO_printf(bio_err, "using curve name prime192v1 "
                            "instead of secp192r1\n");
                        nid = NID_X9_62_prime192v1;
                } else if (!strcmp(ecparam_config.curve_name, "secp256r1")) {
                        BIO_printf(bio_err, "using curve name prime256v1 "
                            "instead of secp256r1\n");
                        nid = NID_X9_62_prime256v1;
                } else
                        nid = OBJ_sn2nid(ecparam_config.curve_name);

                if (nid == 0)
                        nid = EC_curve_nist2nid(ecparam_config.curve_name);

                if (nid == 0) {
                        BIO_printf(bio_err, "unknown curve name (%s)\n",
                            ecparam_config.curve_name);
                        goto end;
                }
                group = EC_GROUP_new_by_curve_name(nid);
                if (group == NULL) {
                        BIO_printf(bio_err, "unable to create curve (%s)\n",
                            ecparam_config.curve_name);
                        goto end;
                }
                EC_GROUP_set_asn1_flag(group, ecparam_config.asn1_flag);
                EC_GROUP_set_point_conversion_form(group, ecparam_config.form);
        } else if (ecparam_config.informat == FORMAT_ASN1) {
                group = d2i_ECPKParameters_bio(in, NULL);
        } else if (ecparam_config.informat == FORMAT_PEM) {
                group = PEM_read_bio_ECPKParameters(in, NULL, NULL, NULL);
        } else {
                BIO_printf(bio_err, "bad input format specified\n");
                goto end;
        }

        if (group == NULL) {
                BIO_printf(bio_err,
                    "unable to load elliptic curve parameters\n");
                ERR_print_errors(bio_err);
                goto end;
        }
        if (ecparam_config.new_form)
                EC_GROUP_set_point_conversion_form(group, ecparam_config.form);

        if (ecparam_config.new_asn1_flag)
                EC_GROUP_set_asn1_flag(group, ecparam_config.asn1_flag);

        if (ecparam_config.no_seed)
                EC_GROUP_set_seed(group, NULL, 0);

        if (ecparam_config.text) {
                if (!ECPKParameters_print(out, group, 0))
                        goto end;
        }
        if (ecparam_config.check) {
                BIO_printf(bio_err, "checking elliptic curve parameters: ");
                if (!EC_GROUP_check(group, NULL)) {
                        BIO_printf(bio_err, "failed\n");
                        ERR_print_errors(bio_err);
                } else
                        BIO_printf(bio_err, "ok\n");

        }
        if (ecparam_config.C) {
                size_t buf_len = 0, tmp_len = 0;
                const EC_POINT *point;
                int is_prime, len = 0;
                const EC_METHOD *meth = EC_GROUP_method_of(group);

                if ((ec_p = BN_new()) == NULL || (ec_a = BN_new()) == NULL ||
                    (ec_b = BN_new()) == NULL || (ec_gen = BN_new()) == NULL ||
                    (ec_order = BN_new()) == NULL ||
                    (ec_cofactor = BN_new()) == NULL) {
                        perror("malloc");
                        goto end;
                }
                is_prime = (EC_METHOD_get_field_type(meth) ==
                    NID_X9_62_prime_field);

                if (!EC_GROUP_get_curve(group, ec_p, ec_a, ec_b, NULL))
                        goto end;

                if ((point = EC_GROUP_get0_generator(group)) == NULL)
                        goto end;
                if (!EC_POINT_point2bn(group, point,
                        EC_GROUP_get_point_conversion_form(group), ec_gen,
                        NULL))
                        goto end;
                if (!EC_GROUP_get_order(group, ec_order, NULL))
                        goto end;
                if (!EC_GROUP_get_cofactor(group, ec_cofactor, NULL))
                        goto end;

                len = BN_num_bits(ec_order);

                if ((tmp_len = (size_t) BN_num_bytes(ec_p)) > buf_len)
                        buf_len = tmp_len;
                if ((tmp_len = (size_t) BN_num_bytes(ec_a)) > buf_len)
                        buf_len = tmp_len;
                if ((tmp_len = (size_t) BN_num_bytes(ec_b)) > buf_len)
                        buf_len = tmp_len;
                if ((tmp_len = (size_t) BN_num_bytes(ec_gen)) > buf_len)
                        buf_len = tmp_len;
                if ((tmp_len = (size_t) BN_num_bytes(ec_order)) > buf_len)
                        buf_len = tmp_len;
                if ((tmp_len = (size_t) BN_num_bytes(ec_cofactor)) > buf_len)
                        buf_len = tmp_len;

                buffer = malloc(buf_len);

                if (buffer == NULL) {
                        perror("malloc");
                        goto end;
                }
                ecparam_print_var(out, ec_p, "ec_p", len, buffer);
                ecparam_print_var(out, ec_a, "ec_a", len, buffer);
                ecparam_print_var(out, ec_b, "ec_b", len, buffer);
                ecparam_print_var(out, ec_gen, "ec_gen", len, buffer);
                ecparam_print_var(out, ec_order, "ec_order", len, buffer);
                ecparam_print_var(out, ec_cofactor, "ec_cofactor", len,
                    buffer);

                BIO_printf(out, "\n\n");

                BIO_printf(out, "EC_GROUP *get_ec_group_%d(void)\n\t{\n", len);
                BIO_printf(out, "\tint ok=0;\n");
                BIO_printf(out, "\tEC_GROUP *group = NULL;\n");
                BIO_printf(out, "\tEC_POINT *point = NULL;\n");
                BIO_printf(out, "\tBIGNUM   *tmp_1 = NULL, *tmp_2 = NULL, "
                    "*tmp_3 = NULL;\n\n");
                BIO_printf(out, "\tif ((tmp_1 = BN_bin2bn(ec_p_%d, "
                    "sizeof(ec_p_%d), NULL)) == NULL)\n\t\t"
                    "goto err;\n", len, len);
                BIO_printf(out, "\tif ((tmp_2 = BN_bin2bn(ec_a_%d, "
                    "sizeof(ec_a_%d), NULL)) == NULL)\n\t\t"
                    "goto err;\n", len, len);
                BIO_printf(out, "\tif ((tmp_3 = BN_bin2bn(ec_b_%d, "
                    "sizeof(ec_b_%d), NULL)) == NULL)\n\t\t"
                    "goto err;\n", len, len);
                if (is_prime) {
                        BIO_printf(out, "\tif ((group = EC_GROUP_new_curve_"
                            "GFp(tmp_1, tmp_2, tmp_3, NULL)) == NULL)"
                            "\n\t\tgoto err;\n\n");
                } else {
                        BIO_printf(out, "\tif ((group = EC_GROUP_new_curve_"
                            "GF2m(tmp_1, tmp_2, tmp_3, NULL)) == NULL)"
                            "\n\t\tgoto err;\n\n");
                }
                BIO_printf(out, "\t/* build generator */\n");
                BIO_printf(out, "\tif ((tmp_1 = BN_bin2bn(ec_gen_%d, "
                    "sizeof(ec_gen_%d), tmp_1)) == NULL)"
                    "\n\t\tgoto err;\n", len, len);
                BIO_printf(out, "\tpoint = EC_POINT_bn2point(group, tmp_1, "
                    "NULL, NULL);\n");
                BIO_printf(out, "\tif (point == NULL)\n\t\tgoto err;\n");
                BIO_printf(out, "\tif ((tmp_2 = BN_bin2bn(ec_order_%d, "
                    "sizeof(ec_order_%d), tmp_2)) == NULL)"
                    "\n\t\tgoto err;\n", len, len);
                BIO_printf(out, "\tif ((tmp_3 = BN_bin2bn(ec_cofactor_%d, "
                    "sizeof(ec_cofactor_%d), tmp_3)) == NULL)"
                    "\n\t\tgoto err;\n", len, len);
                BIO_printf(out, "\tif (!EC_GROUP_set_generator(group, point,"
                    " tmp_2, tmp_3))\n\t\tgoto err;\n");
                BIO_printf(out, "\n\tok=1;\n");
                BIO_printf(out, "err:\n");
                BIO_printf(out, "\tif (tmp_1)\n\t\tBN_free(tmp_1);\n");
                BIO_printf(out, "\tif (tmp_2)\n\t\tBN_free(tmp_2);\n");
                BIO_printf(out, "\tif (tmp_3)\n\t\tBN_free(tmp_3);\n");
                BIO_printf(out, "\tif (point)\n\t\tEC_POINT_free(point);\n");
                BIO_printf(out, "\tif (!ok)\n");
                BIO_printf(out, "\t\t{\n");
                BIO_printf(out, "\t\tEC_GROUP_free(group);\n");
                BIO_printf(out, "\t\tgroup = NULL;\n");
                BIO_printf(out, "\t\t}\n");
                BIO_printf(out, "\treturn(group);\n\t}\n");
        }
        if (!ecparam_config.noout) {
                if (ecparam_config.outformat == FORMAT_ASN1)
                        i = i2d_ECPKParameters_bio(out, group);
                else if (ecparam_config.outformat == FORMAT_PEM)
                        i = PEM_write_bio_ECPKParameters(out, group);
                else {
                        BIO_printf(bio_err, "bad output format specified for"
                            " outfile\n");
                        goto end;
                }
                if (!i) {
                        BIO_printf(bio_err, "unable to write elliptic "
                            "curve parameters\n");
                        ERR_print_errors(bio_err);
                        goto end;
                }
        }
        if (ecparam_config.genkey) {
                EC_KEY *eckey = EC_KEY_new();

                if (eckey == NULL)
                        goto end;

                if (EC_KEY_set_group(eckey, group) == 0) {
                        EC_KEY_free(eckey);
                        goto end;
                }

                if (!EC_KEY_generate_key(eckey)) {
                        EC_KEY_free(eckey);
                        goto end;
                }
                if (ecparam_config.outformat == FORMAT_ASN1)
                        i = i2d_ECPrivateKey_bio(out, eckey);
                else if (ecparam_config.outformat == FORMAT_PEM)
                        i = PEM_write_bio_ECPrivateKey(out, eckey, NULL,
                            NULL, 0, NULL, NULL);
                else {
                        BIO_printf(bio_err, "bad output format specified "
                            "for outfile\n");
                        EC_KEY_free(eckey);
                        goto end;
                }
                EC_KEY_free(eckey);
        }
        ret = 0;

 end:
        BN_free(ec_p);
        BN_free(ec_a);
        BN_free(ec_b);
        BN_free(ec_gen);
        BN_free(ec_order);
        BN_free(ec_cofactor);

        free(buffer);

        BIO_free(in);
        BIO_free_all(out);
        EC_GROUP_free(group);

        return (ret);
}

static int
ecparam_print_var(BIO * out, BIGNUM * in, const char *var,
    int len, unsigned char *buffer)
{
        BIO_printf(out, "static unsigned char %s_%d[] = {", var, len);
        if (BN_is_zero(in))
                BIO_printf(out, "\n\t0x00");
        else {
                int i, l;

                l = BN_bn2bin(in, buffer);
                for (i = 0; i < l - 1; i++) {
                        if ((i % 12) == 0)
                                BIO_printf(out, "\n\t");
                        BIO_printf(out, "0x%02X,", buffer[i]);
                }
                if ((i % 12) == 0)
                        BIO_printf(out, "\n\t");
                BIO_printf(out, "0x%02X", buffer[i]);
        }
        BIO_printf(out, "\n\t};\n\n");
        return 1;
}
#endif