fix provider signatures

[thirdparty/openssl.git] / providers / common / check_fips.c

/*
 * Copyright 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 "internal/deprecated.h"

#include <openssl/rsa.h>
#include <openssl/dsa.h>
#include <openssl/dh.h>
#include <openssl/ec.h>
#include <openssl/err.h>
#include <openssl/core_names.h>
#include <openssl/obj_mac.h>
#include "prov/check.h"
#include "prov/providercommonerr.h"

/*
 * FIPS requires a minimum security strength of 112 bits (for encryption or
 * signing), and for legacy purposes 80 bits (for decryption or verifying).
 * Set protect = 1 for encryption or signing operations, or 0 otherwise. See
 * https://nvlpubs.nist.gov/nistpubs/SpecialPublications/NIST.SP.800-131Ar2.pdf.
 */
int rsa_check_key(const RSA *rsa, int protect)
{
    int sz = RSA_bits(rsa);

    return protect ? (sz >= 2048) : (sz >= 1024);
}

#ifndef OPENSSL_NO_EC
/*
 * In FIPS mode:
 * protect should be 1 for any operations that need 112 bits of security
 * strength (such as signing, and key exchange), or 0 for operations that allow
 * a lower security strength (such as verify).
 *
 * For ECDH key agreement refer to SP800-56A
 * https://nvlpubs.nist.gov/nistpubs/SpecialPublications/NIST.SP.800-56Ar3.pdf
 * "Appendix D"
 *
 * For ECDSA signatures refer to
 * https://nvlpubs.nist.gov/nistpubs/SpecialPublications/NIST.SP.800-131Ar2.pdf
 * "Table 2"
 */
int ec_check_key(const EC_KEY *ec, int protect)
{
    int nid, strength;
    const char *curve_name;
    const EC_GROUP *group = EC_KEY_get0_group(ec);

    if (group == NULL) {
        ERR_raise_data(ERR_LIB_PROV, PROV_R_INVALID_CURVE, "No group");
        return 0;
    }
    nid = EC_GROUP_get_curve_name(group);
    if (nid == NID_undef) {
        ERR_raise_data(ERR_LIB_PROV, PROV_R_INVALID_CURVE,
                       "Explicit curves are not allowed in fips mode");
        return 0;
    }

    curve_name = EC_curve_nid2nist(nid);
    if (curve_name == NULL) {
        ERR_raise_data(ERR_LIB_PROV, PROV_R_INVALID_CURVE,
                       "Curve %s is not approved in FIPS mode", curve_name);
        return 0;
    }

    /*
     * For EC the security strength is the (order_bits / 2)
     * e.g. P-224 is 112 bits.
     */
    strength = EC_GROUP_order_bits(group) / 2;
    /* The min security strength allowed for legacy verification is 80 bits */
    if (strength < 80) {
        ERR_raise(ERR_LIB_PROV, PROV_R_INVALID_CURVE);
        return 0;
    }

    /*
     * For signing or key agreement only allow curves with at least 112 bits of
     * security strength
     */
    if (protect && strength < 112) {
        ERR_raise_data(ERR_LIB_PROV, PROV_R_INVALID_CURVE,
                       "Curve %s cannot be used for signing", curve_name);
        return 0;
    }
    return 1;
}
#endif /* OPENSSL_NO_EC */

#ifndef OPENSSL_NO_DSA
/*
 * Check for valid key sizes if fips mode. Refer to
 * https://nvlpubs.nist.gov/nistpubs/SpecialPublications/NIST.SP.800-131Ar2.pdf
 * "Table 2"
 */
int dsa_check_key(const DSA *dsa, int sign)
{
    size_t L, N;
    const BIGNUM *p, *q;

    if (dsa == NULL)
        return 0;

    p = DSA_get0_p(dsa);
    q = DSA_get0_q(dsa);
    if (p == NULL || q == NULL)
        return 0;

    L = BN_num_bits(p);
    N = BN_num_bits(q);

    /*
     * Valid sizes or verification - Note this could be a fips186-2 type
     * key - so we allow 512 also. When this is no longer suppported the
     * lower bound should be increased to 1024.
     */
    if (!sign)
        return (L >= 512 && N >= 160);

     /* Valid sizes for both sign and verify */
    if (L == 2048 && (N == 224 || N == 256))
        return 1;
    return (L == 3072 && N == 256);
}
#endif /* OPENSSL_NO_DSA */

#ifndef OPENSSL_NO_DH
/*
 * For DH key agreement refer to SP800-56A
 * https://nvlpubs.nist.gov/nistpubs/SpecialPublications/NIST.SP.800-56Ar3.pdf
 * "Section 5.5.1.1FFC Domain Parameter Selection/Generation" and
 * "Appendix D" FFC Safe-prime Groups
 */
int dh_check_key(const DH *dh)
{
    size_t L, N;
    const BIGNUM *p, *q;

    if (dh == NULL)
        return 0;

    p = DH_get0_p(dh);
    q = DH_get0_q(dh);
    if (p == NULL || q == NULL)
        return 0;

    L = BN_num_bits(p);
    if (L < 2048)
        return 0;

    /* If it is a safe prime group then it is ok */
    if (DH_get_nid(dh))
        return 1;

    /* If not then it must be FFC, which only allows certain sizes. */
    N = BN_num_bits(q);

    return (L == 2048 && (N == 224 || N == 256));
}
#endif /* OPENSSL_NO_DH */

int digest_get_approved_nid_with_sha1(const EVP_MD *md, int sha1_allowed)
{
    int mdnid = digest_get_approved_nid(md);

    if (mdnid == NID_sha1 && !sha1_allowed)
        mdnid = NID_undef;

    return mdnid;
}

int digest_is_allowed(const EVP_MD *md)
{
    return (digest_get_approved_nid(md) != NID_undef);
}

int digest_rsa_sign_get_md_nid(const EVP_MD *md, int sha1_allowed)
{
    return digest_get_approved_nid_with_sha1(md, sha1_allowed);
}