/*
 * Copyright 2002-2020 The OpenSSL Project Authors. All Rights Reserved.
 *
 * Licensed under the Apache License 2.0 (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 <openssl/opensslconf.h>

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "apps.h"
#include "progs.h"
#include <openssl/bio.h>
#include <openssl/err.h>
#include <openssl/evp.h>
#include <openssl/pem.h>

static OPT_PAIR conv_forms[] = {
    {"compressed", POINT_CONVERSION_COMPRESSED},
    {"uncompressed", POINT_CONVERSION_UNCOMPRESSED},
    {"hybrid", POINT_CONVERSION_HYBRID},
    {NULL}
};

static OPT_PAIR param_enc[] = {
    {"named_curve", OPENSSL_EC_NAMED_CURVE},
    {"explicit", 0},
    {NULL}
};

typedef enum OPTION_choice {
    OPT_ERR = -1, OPT_EOF = 0, OPT_HELP,
    OPT_INFORM, OPT_OUTFORM, OPT_ENGINE, OPT_IN, OPT_OUT,
    OPT_NOOUT, OPT_TEXT, OPT_PARAM_OUT, OPT_PUBIN, OPT_PUBOUT,
    OPT_PASSIN, OPT_PASSOUT, OPT_PARAM_ENC, OPT_CONV_FORM, OPT_CIPHER,
    OPT_NO_PUBLIC, OPT_CHECK, OPT_PROV_ENUM
} OPTION_CHOICE;

const OPTIONS ec_options[] = {
    OPT_SECTION("General"),
    {"help", OPT_HELP, '-', "Display this summary"},
#ifndef OPENSSL_NO_ENGINE
    {"engine", OPT_ENGINE, 's', "Use engine, possibly a hardware device"},
#endif

    OPT_SECTION("Input"),
    {"in", OPT_IN, 's', "Input file"},
    {"inform", OPT_INFORM, 'f', "Input format (DER/PEM/P12/ENGINE)"},
    {"pubin", OPT_PUBIN, '-', "Expect a public key in input file"},
    {"passin", OPT_PASSIN, 's', "Input file pass phrase source"},
    {"check", OPT_CHECK, '-', "check key consistency"},
    {"", OPT_CIPHER, '-', "Any supported cipher"},
    {"param_enc", OPT_PARAM_ENC, 's',
     "Specifies the way the ec parameters are encoded"},
    {"conv_form", OPT_CONV_FORM, 's', "Specifies the point conversion form "},

    OPT_SECTION("Output"),
    {"out", OPT_OUT, '>', "Output file"},
    {"outform", OPT_OUTFORM, 'F', "Output format - DER or PEM"},
    {"noout", OPT_NOOUT, '-', "Don't print key out"},
    {"text", OPT_TEXT, '-', "Print the key"},
    {"param_out", OPT_PARAM_OUT, '-', "Print the elliptic curve parameters"},
    {"pubout", OPT_PUBOUT, '-', "Output public key, not private"},
    {"no_public", OPT_NO_PUBLIC, '-', "exclude public key from private key"},
    {"passout", OPT_PASSOUT, 's', "Output file pass phrase source"},

    OPT_PROV_OPTIONS,
    {NULL}
};

int ec_main(int argc, char **argv)
{
    BIO *in = NULL, *out = NULL;
    ENGINE *e = NULL;
    EC_KEY *eckey = NULL;
    const EC_GROUP *group;
    const EVP_CIPHER *enc = NULL;
    point_conversion_form_t form = POINT_CONVERSION_UNCOMPRESSED;
    char *infile = NULL, *outfile = NULL, *prog;
    char *passin = NULL, *passout = NULL, *passinarg = NULL, *passoutarg = NULL;
    OPTION_CHOICE o;
    int asn1_flag = OPENSSL_EC_NAMED_CURVE, new_form = 0, new_asn1_flag = 0;
    int informat = FORMAT_PEM, outformat = FORMAT_PEM, text = 0, noout = 0;
    int pubin = 0, pubout = 0, param_out = 0, i, ret = 1, private = 0;
    int no_public = 0, check = 0;

    prog = opt_init(argc, argv, ec_options);
    while ((o = opt_next()) != OPT_EOF) {
        switch (o) {
        case OPT_EOF:
        case OPT_ERR:
 opthelp:
            BIO_printf(bio_err, "%s: Use -help for summary.\n", prog);
            goto end;
        case OPT_HELP:
            opt_help(ec_options);
            ret = 0;
            goto end;
        case OPT_INFORM:
            if (!opt_format(opt_arg(), OPT_FMT_ANY, &informat))
                goto opthelp;
            break;
        case OPT_IN:
            infile = opt_arg();
            break;
        case OPT_OUTFORM:
            if (!opt_format(opt_arg(), OPT_FMT_PEMDER, &outformat))
                goto opthelp;
            break;
        case OPT_OUT:
            outfile = opt_arg();
            break;
        case OPT_NOOUT:
            noout = 1;
            break;
        case OPT_TEXT:
            text = 1;
            break;
        case OPT_PARAM_OUT:
            param_out = 1;
            break;
        case OPT_PUBIN:
            pubin = 1;
            break;
        case OPT_PUBOUT:
            pubout = 1;
            break;
        case OPT_PASSIN:
            passinarg = opt_arg();
            break;
        case OPT_PASSOUT:
            passoutarg = opt_arg();
            break;
        case OPT_ENGINE:
            e = setup_engine(opt_arg(), 0);
            break;
        case OPT_CIPHER:
            if (!opt_cipher(opt_unknown(), &enc))
                goto opthelp;
            break;
        case OPT_CONV_FORM:
            if (!opt_pair(opt_arg(), conv_forms, &i))
                goto opthelp;
            new_form = 1;
            form = i;
            break;
        case OPT_PARAM_ENC:
            if (!opt_pair(opt_arg(), param_enc, &i))
                goto opthelp;
            new_asn1_flag = 1;
            asn1_flag = i;
            break;
        case OPT_NO_PUBLIC:
            no_public = 1;
            break;
        case OPT_CHECK:
            check = 1;
            break;
        case OPT_PROV_CASES:
            if (!opt_provider(o))
                goto end;
            break;
        }
    }
    argc = opt_num_rest();
    if (argc != 0)
        goto opthelp;

    private = param_out || pubin || pubout ? 0 : 1;
    if (text && !pubin)
        private = 1;

    if (!app_passwd(passinarg, passoutarg, &passin, &passout)) {
        BIO_printf(bio_err, "Error getting passwords\n");
        goto end;
    }

    if (informat != FORMAT_ENGINE) {
        in = bio_open_default(infile, 'r', informat);
        if (in == NULL)
            goto end;
    }

    BIO_printf(bio_err, "read EC key\n");
    if (informat == FORMAT_ASN1) {
        if (pubin)
            eckey = d2i_EC_PUBKEY_bio(in, NULL);
        else
            eckey = d2i_ECPrivateKey_bio(in, NULL);
    } else if (informat == FORMAT_ENGINE) {
        EVP_PKEY *pkey;
        if (pubin)
            pkey = load_pubkey(infile, informat, 1, passin, e, "Public Key");
        else
            pkey = load_key(infile, informat, 1, passin, e, "Private Key");
        if (pkey != NULL) {
            eckey = EVP_PKEY_get1_EC_KEY(pkey);
            EVP_PKEY_free(pkey);
        }
    } else {
        if (pubin)
            eckey = PEM_read_bio_EC_PUBKEY(in, NULL, NULL, NULL);
        else
            eckey = PEM_read_bio_ECPrivateKey(in, NULL, NULL, passin);
    }
    if (eckey == NULL) {
        BIO_printf(bio_err, "unable to load Key\n");
        ERR_print_errors(bio_err);
        goto end;
    }

    out = bio_open_owner(outfile, outformat, private);
    if (out == NULL)
        goto end;

    group = EC_KEY_get0_group(eckey);

    if (new_form)
        EC_KEY_set_conv_form(eckey, form);

    if (new_asn1_flag)
        EC_KEY_set_asn1_flag(eckey, asn1_flag);

    if (no_public)
        EC_KEY_set_enc_flags(eckey, EC_PKEY_NO_PUBKEY);

    if (text) {
        assert(pubin || private);
        if (!EC_KEY_print(out, eckey, 0)) {
            perror(outfile);
            ERR_print_errors(bio_err);
            goto end;
        }
    }

    if (check) {
        if (EC_KEY_check_key(eckey) == 1) {
            BIO_printf(bio_err, "EC Key valid.\n");
        } else {
            BIO_printf(bio_err, "EC Key Invalid!\n");
            ERR_print_errors(bio_err);
        }
    }

    if (noout) {
        ret = 0;
        goto end;
    }

    BIO_printf(bio_err, "writing EC key\n");
    if (outformat == FORMAT_ASN1) {
        if (param_out) {
            i = i2d_ECPKParameters_bio(out, group);
        } else if (pubin || pubout) {
            i = i2d_EC_PUBKEY_bio(out, eckey);
        } else {
            assert(private);
            i = i2d_ECPrivateKey_bio(out, eckey);
        }
    } else {
        if (param_out) {
            i = PEM_write_bio_ECPKParameters(out, group);
        } else if (pubin || pubout) {
            i = PEM_write_bio_EC_PUBKEY(out, eckey);
        } else {
            assert(private);
            i = PEM_write_bio_ECPrivateKey(out, eckey, enc,
                                           NULL, 0, NULL, passout);
        }
    }

    if (!i) {
        BIO_printf(bio_err, "unable to write private key\n");
        ERR_print_errors(bio_err);
    } else {
        ret = 0;
    }
 end:
    BIO_free(in);
    BIO_free_all(out);
    EC_KEY_free(eckey);
    release_engine(e);
    OPENSSL_free(passin);
    OPENSSL_free(passout);
    return ret;
}