/*

 * Copyright 1999-2023 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

 */

/*

 * RSA low level APIs are deprecated for public use, but still ok for

 * internal use.

 */

#include "internal/deprecated.h"

#include <openssl/bn.h>

#include <openssl/err.h>

#include "crypto/rsa.h"

#include "rsa_local.h"

#ifndef FIPS_MODULE

static int rsa_validate_keypair_multiprime(const RSA *key, BN_GENCB *cb)

{

    BIGNUM *i, *j, *k, *l, *m;

    BN_CTX *ctx;

    int ret = 1, ex_primes = 0, idx;

    RSA_PRIME_INFO *pinfo;

    if (key->p == NULL || key->q == NULL || key->n == NULL

            || key->e == NULL || key->d == NULL) {

        ERR_raise(ERR_LIB_RSA, RSA_R_VALUE_MISSING);

        return 0;

    }

    /* multi-prime? */

    if (key->version == RSA_ASN1_VERSION_MULTI) {

        ex_primes = sk_RSA_PRIME_INFO_num(key->prime_infos);

        if (ex_primes <= 0

                || (ex_primes + 2) > ossl_rsa_multip_cap(BN_num_bits(key->n))) {

            ERR_raise(ERR_LIB_RSA, RSA_R_INVALID_MULTI_PRIME_KEY);

            return 0;

        }

    }

    i = BN_new();

    j = BN_new();

    k = BN_new();

    l = BN_new();

    m = BN_new();

    ctx = BN_CTX_new_ex(key->libctx);

    if (i == NULL || j == NULL || k == NULL || l == NULL

            || m == NULL || ctx == NULL) {

        ret = -1;

        ERR_raise(ERR_LIB_RSA, ERR_R_MALLOC_FAILURE);

        goto err;

    }

    if (BN_is_one(key->e)) {

        ret = 0;

        ERR_raise(ERR_LIB_RSA, RSA_R_BAD_E_VALUE);

    }

    if (!BN_is_odd(key->e)) {

        ret = 0;

        ERR_raise(ERR_LIB_RSA, RSA_R_BAD_E_VALUE);

    }

    /* p prime? */

    if (BN_check_prime(key->p, ctx, cb) != 1) {

        ret = 0;

        ERR_raise(ERR_LIB_RSA, RSA_R_P_NOT_PRIME);

    }

    /* q prime? */

    if (BN_check_prime(key->q, ctx, cb) != 1) {

        ret = 0;

        ERR_raise(ERR_LIB_RSA, RSA_R_Q_NOT_PRIME);

    }

    /* r_i prime? */

    for (idx = 0; idx < ex_primes; idx++) {

        pinfo = sk_RSA_PRIME_INFO_value(key->prime_infos, idx);

        if (BN_check_prime(pinfo->r, ctx, cb) != 1) {

            ret = 0;

            ERR_raise(ERR_LIB_RSA, RSA_R_MP_R_NOT_PRIME);

        }

    }

    /* n = p*q * r_3...r_i? */

    if (!BN_mul(i, key->p, key->q, ctx)) {

        ret = -1;

        goto err;

    }

    for (idx = 0; idx < ex_primes; idx++) {

        pinfo = sk_RSA_PRIME_INFO_value(key->prime_infos, idx);

        if (!BN_mul(i, i, pinfo->r, ctx)) {

            ret = -1;

            goto err;

        }

    }

    if (BN_cmp(i, key->n) != 0) {

        ret = 0;

        if (ex_primes)

            ERR_raise(ERR_LIB_RSA, RSA_R_N_DOES_NOT_EQUAL_PRODUCT_OF_PRIMES);

        else

            ERR_raise(ERR_LIB_RSA, RSA_R_N_DOES_NOT_EQUAL_P_Q);

    }

    /* d*e = 1  mod \lambda(n)? */

    if (!BN_sub(i, key->p, BN_value_one())) {

        ret = -1;

        goto err;

    }

    if (!BN_sub(j, key->q, BN_value_one())) {

        ret = -1;

        goto err;

    }

    /* now compute k = \lambda(n) = LCM(i, j, r_3 - 1...) */

    if (!BN_mul(l, i, j, ctx)) {

        ret = -1;

        goto err;

    }

    if (!BN_gcd(m, i, j, ctx)) {

        ret = -1;

        goto err;

    }

    if (!BN_div(m, NULL, l, m, ctx)) { /* remainder is 0 */

        ret = -1;

        goto err;

    }

    for (idx = 0; idx < ex_primes; idx++) {

        pinfo = sk_RSA_PRIME_INFO_value(key->prime_infos, idx);

        if (!BN_sub(k, pinfo->r, BN_value_one())) {

            ret = -1;

            goto err;

        }

        if (!BN_mul(l, m, k, ctx)) {

            ret = -1;

            goto err;

        }

        if (!BN_gcd(m, m, k, ctx)) {

            ret = -1;

            goto err;

        }

        if (!BN_div(m, NULL, l, m, ctx)) { /* remainder is 0 */

            ret = -1;

            goto err;

        }

    }

    if (!BN_mod_mul(i, key->d, key->e, m, ctx)) {

        ret = -1;

        goto err;

    }

    if (!BN_is_one(i)) {

        ret = 0;

        ERR_raise(ERR_LIB_RSA, RSA_R_D_E_NOT_CONGRUENT_TO_1);

    }

    if (key->dmp1 != NULL && key->dmq1 != NULL && key->iqmp != NULL) {

        /* dmp1 = d mod (p-1)? */

        if (!BN_sub(i, key->p, BN_value_one())) {

            ret = -1;

            goto err;

        }

        if (!BN_mod(j, key->d, i, ctx)) {

            ret = -1;

            goto err;

        }

        if (BN_cmp(j, key->dmp1) != 0) {

            ret = 0;

            ERR_raise(ERR_LIB_RSA, RSA_R_DMP1_NOT_CONGRUENT_TO_D);

        }

        /* dmq1 = d mod (q-1)? */

        if (!BN_sub(i, key->q, BN_value_one())) {

            ret = -1;

            goto err;

        }

        if (!BN_mod(j, key->d, i, ctx)) {

            ret = -1;

            goto err;

        }

        if (BN_cmp(j, key->dmq1) != 0) {

            ret = 0;

            ERR_raise(ERR_LIB_RSA, RSA_R_DMQ1_NOT_CONGRUENT_TO_D);

        }

        /* iqmp = q^-1 mod p? */

        if (!BN_mod_inverse(i, key->q, key->p, ctx)) {

            ret = -1;

            goto err;

        }

        if (BN_cmp(i, key->iqmp) != 0) {

            ret = 0;

            ERR_raise(ERR_LIB_RSA, RSA_R_IQMP_NOT_INVERSE_OF_Q);

        }

    }

    for (idx = 0; idx < ex_primes; idx++) {

        pinfo = sk_RSA_PRIME_INFO_value(key->prime_infos, idx);

        /* d_i = d mod (r_i - 1)? */

        if (!BN_sub(i, pinfo->r, BN_value_one())) {

            ret = -1;

            goto err;

        }

        if (!BN_mod(j, key->d, i, ctx)) {

            ret = -1;

            goto err;

        }

        if (BN_cmp(j, pinfo->d) != 0) {

            ret = 0;

            ERR_raise(ERR_LIB_RSA, RSA_R_MP_EXPONENT_NOT_CONGRUENT_TO_D);

        }

        /* t_i = R_i ^ -1 mod r_i ? */

        if (!BN_mod_inverse(i, pinfo->pp, pinfo->r, ctx)) {

            ret = -1;

            goto err;

        }

        if (BN_cmp(i, pinfo->t) != 0) {

            ret = 0;

            ERR_raise(ERR_LIB_RSA, RSA_R_MP_COEFFICIENT_NOT_INVERSE_OF_R);

        }

    }

 err:

    BN_free(i);

    BN_free(j);

    BN_free(k);

    BN_free(l);

    BN_free(m);

    BN_CTX_free(ctx);

    return ret;

}

#endif /* FIPS_MODULE */

int ossl_rsa_validate_public(const RSA *key)

{

    return ossl_rsa_sp800_56b_check_public(key);

}

int ossl_rsa_validate_private(const RSA *key)

{

    return ossl_rsa_sp800_56b_check_private(key);

}

int ossl_rsa_validate_pairwise(const RSA *key)

{

#ifdef FIPS_MODULE

    return ossl_rsa_sp800_56b_check_keypair(key, NULL, -1, RSA_bits(key));

#else

    return rsa_validate_keypair_multiprime(key, NULL) > 0;

#endif

}

int RSA_check_key(const RSA *key)

{

    return RSA_check_key_ex(key, NULL);

}

int RSA_check_key_ex(const RSA *key, BN_GENCB *cb)

{

#ifdef FIPS_MODULE

    return ossl_rsa_validate_public(key)

           && ossl_rsa_validate_private(key)

           && ossl_rsa_validate_pairwise(key);

#else

    return rsa_validate_keypair_multiprime(key, cb);

#endif /* FIPS_MODULE */

}