openssl/crypto/rsa/rsa_lib.c
Andy Polyakov 0122add654 rsa/rsa_lib.c: make RSA_security_bits multi-prime aware.
Multi-prime RSA security is not determined by modulus length alone, but
depends even on number of primes. Too many primes render security
inadequate, but there is no common amount of primes or common factors'
length that provide equivalent secuity promise as two-prime for given
modulus length. Maximum amount of permitted primes is determined
according to following table.

   <1024 | >=1024 | >=4096 | >=8192
   ------+--------+--------+-------
     2   |   3    |   4    |   5

Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/4791)
2017-11-28 20:04:57 +01:00

440 lines
10 KiB
C

/*
* Copyright 1995-2017 The OpenSSL Project Authors. All Rights Reserved.
*
* Licensed under the OpenSSL license (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 <stdio.h>
#include <openssl/crypto.h>
#include "internal/cryptlib.h"
#include "internal/refcount.h"
#include "internal/bn_int.h"
#include <openssl/engine.h>
#include <openssl/evp.h>
#include "internal/evp_int.h"
#include "rsa_locl.h"
RSA *RSA_new(void)
{
return RSA_new_method(NULL);
}
const RSA_METHOD *RSA_get_method(const RSA *rsa)
{
return rsa->meth;
}
int RSA_set_method(RSA *rsa, const RSA_METHOD *meth)
{
/*
* NB: The caller is specifically setting a method, so it's not up to us
* to deal with which ENGINE it comes from.
*/
const RSA_METHOD *mtmp;
mtmp = rsa->meth;
if (mtmp->finish)
mtmp->finish(rsa);
#ifndef OPENSSL_NO_ENGINE
ENGINE_finish(rsa->engine);
rsa->engine = NULL;
#endif
rsa->meth = meth;
if (meth->init)
meth->init(rsa);
return 1;
}
RSA *RSA_new_method(ENGINE *engine)
{
RSA *ret = OPENSSL_zalloc(sizeof(*ret));
if (ret == NULL) {
RSAerr(RSA_F_RSA_NEW_METHOD, ERR_R_MALLOC_FAILURE);
return NULL;
}
ret->references = 1;
ret->lock = CRYPTO_THREAD_lock_new();
if (ret->lock == NULL) {
RSAerr(RSA_F_RSA_NEW_METHOD, ERR_R_MALLOC_FAILURE);
OPENSSL_free(ret);
return NULL;
}
ret->meth = RSA_get_default_method();
#ifndef OPENSSL_NO_ENGINE
ret->flags = ret->meth->flags & ~RSA_FLAG_NON_FIPS_ALLOW;
if (engine) {
if (!ENGINE_init(engine)) {
RSAerr(RSA_F_RSA_NEW_METHOD, ERR_R_ENGINE_LIB);
goto err;
}
ret->engine = engine;
} else {
ret->engine = ENGINE_get_default_RSA();
}
if (ret->engine) {
ret->meth = ENGINE_get_RSA(ret->engine);
if (ret->meth == NULL) {
RSAerr(RSA_F_RSA_NEW_METHOD, ERR_R_ENGINE_LIB);
goto err;
}
}
#endif
ret->flags = ret->meth->flags & ~RSA_FLAG_NON_FIPS_ALLOW;
if (!CRYPTO_new_ex_data(CRYPTO_EX_INDEX_RSA, ret, &ret->ex_data)) {
goto err;
}
if ((ret->meth->init != NULL) && !ret->meth->init(ret)) {
RSAerr(RSA_F_RSA_NEW_METHOD, ERR_R_INIT_FAIL);
goto err;
}
return ret;
err:
RSA_free(ret);
return NULL;
}
void RSA_free(RSA *r)
{
int i;
if (r == NULL)
return;
CRYPTO_DOWN_REF(&r->references, &i, r->lock);
REF_PRINT_COUNT("RSA", r);
if (i > 0)
return;
REF_ASSERT_ISNT(i < 0);
if (r->meth->finish)
r->meth->finish(r);
#ifndef OPENSSL_NO_ENGINE
ENGINE_finish(r->engine);
#endif
CRYPTO_free_ex_data(CRYPTO_EX_INDEX_RSA, r, &r->ex_data);
CRYPTO_THREAD_lock_free(r->lock);
BN_clear_free(r->n);
BN_clear_free(r->e);
BN_clear_free(r->d);
BN_clear_free(r->p);
BN_clear_free(r->q);
BN_clear_free(r->dmp1);
BN_clear_free(r->dmq1);
BN_clear_free(r->iqmp);
RSA_PSS_PARAMS_free(r->pss);
sk_RSA_PRIME_INFO_pop_free(r->prime_infos, rsa_multip_info_free);
BN_BLINDING_free(r->blinding);
BN_BLINDING_free(r->mt_blinding);
OPENSSL_free(r->bignum_data);
OPENSSL_free(r);
}
int RSA_up_ref(RSA *r)
{
int i;
if (CRYPTO_UP_REF(&r->references, &i, r->lock) <= 0)
return 0;
REF_PRINT_COUNT("RSA", r);
REF_ASSERT_ISNT(i < 2);
return i > 1 ? 1 : 0;
}
int RSA_set_ex_data(RSA *r, int idx, void *arg)
{
return CRYPTO_set_ex_data(&r->ex_data, idx, arg);
}
void *RSA_get_ex_data(const RSA *r, int idx)
{
return CRYPTO_get_ex_data(&r->ex_data, idx);
}
int RSA_security_bits(const RSA *rsa)
{
int bits = BN_num_bits(rsa->n);
if (rsa->version == RSA_ASN1_VERSION_MULTI) {
/* This ought to mean that we have private key at hand. */
int ex_primes = sk_RSA_PRIME_INFO_num(rsa->prime_infos);
if (ex_primes <= 0 || (ex_primes + 2) > rsa_multip_cap(bits))
return 0;
}
return BN_security_bits(bits, -1);
}
int RSA_set0_key(RSA *r, BIGNUM *n, BIGNUM *e, BIGNUM *d)
{
/* If the fields n and e in r are NULL, the corresponding input
* parameters MUST be non-NULL for n and e. d may be
* left NULL (in case only the public key is used).
*/
if ((r->n == NULL && n == NULL)
|| (r->e == NULL && e == NULL))
return 0;
if (n != NULL) {
BN_free(r->n);
r->n = n;
}
if (e != NULL) {
BN_free(r->e);
r->e = e;
}
if (d != NULL) {
BN_free(r->d);
r->d = d;
}
return 1;
}
int RSA_set0_factors(RSA *r, BIGNUM *p, BIGNUM *q)
{
/* If the fields p and q in r are NULL, the corresponding input
* parameters MUST be non-NULL.
*/
if ((r->p == NULL && p == NULL)
|| (r->q == NULL && q == NULL))
return 0;
if (p != NULL) {
BN_free(r->p);
r->p = p;
}
if (q != NULL) {
BN_free(r->q);
r->q = q;
}
return 1;
}
int RSA_set0_crt_params(RSA *r, BIGNUM *dmp1, BIGNUM *dmq1, BIGNUM *iqmp)
{
/* If the fields dmp1, dmq1 and iqmp in r are NULL, the corresponding input
* parameters MUST be non-NULL.
*/
if ((r->dmp1 == NULL && dmp1 == NULL)
|| (r->dmq1 == NULL && dmq1 == NULL)
|| (r->iqmp == NULL && iqmp == NULL))
return 0;
if (dmp1 != NULL) {
BN_free(r->dmp1);
r->dmp1 = dmp1;
}
if (dmq1 != NULL) {
BN_free(r->dmq1);
r->dmq1 = dmq1;
}
if (iqmp != NULL) {
BN_free(r->iqmp);
r->iqmp = iqmp;
}
return 1;
}
/*
* Is it better to export RSA_PRIME_INFO structure
* and related functions to let user pass a triplet?
*/
int RSA_set0_multi_prime_params(RSA *r, BIGNUM *primes[], BIGNUM *exps[],
BIGNUM *coeffs[], int pnum)
{
STACK_OF(RSA_PRIME_INFO) *prime_infos, *old = NULL;
RSA_PRIME_INFO *pinfo;
int i;
if (primes == NULL || exps == NULL || coeffs == NULL || pnum == 0)
return 0;
prime_infos = sk_RSA_PRIME_INFO_new_reserve(NULL, pnum);
if (prime_infos == NULL)
return 0;
if (r->prime_infos != NULL)
old = r->prime_infos;
for (i = 0; i < pnum; i++) {
pinfo = rsa_multip_info_new();
if (pinfo == NULL)
goto err;
if (primes[i] != NULL && exps[i] != NULL && coeffs[i] != NULL) {
BN_free(pinfo->r);
BN_free(pinfo->d);
BN_free(pinfo->t);
pinfo->r = primes[i];
pinfo->d = exps[i];
pinfo->t = coeffs[i];
} else {
rsa_multip_info_free(pinfo);
goto err;
}
(void)sk_RSA_PRIME_INFO_push(prime_infos, pinfo);
}
r->prime_infos = prime_infos;
if (!rsa_multip_calc_product(r)) {
r->prime_infos = old;
goto err;
}
if (old != NULL) {
/*
* This is hard to deal with, since the old infos could
* also be set by this function and r, d, t should not
* be freed in that case. So currently, stay consistent
* with other *set0* functions: just free it...
*/
sk_RSA_PRIME_INFO_pop_free(old, rsa_multip_info_free);
}
r->version = RSA_ASN1_VERSION_MULTI;
return 1;
err:
/* r, d, t should not be freed */
sk_RSA_PRIME_INFO_pop_free(prime_infos, rsa_multip_info_free_ex);
return 0;
}
void RSA_get0_key(const RSA *r,
const BIGNUM **n, const BIGNUM **e, const BIGNUM **d)
{
if (n != NULL)
*n = r->n;
if (e != NULL)
*e = r->e;
if (d != NULL)
*d = r->d;
}
void RSA_get0_factors(const RSA *r, const BIGNUM **p, const BIGNUM **q)
{
if (p != NULL)
*p = r->p;
if (q != NULL)
*q = r->q;
}
int RSA_get_multi_prime_extra_count(const RSA *r)
{
int pnum;
pnum = sk_RSA_PRIME_INFO_num(r->prime_infos);
if (pnum <= 0)
pnum = 0;
return pnum;
}
int RSA_get0_multi_prime_factors(const RSA *r, const BIGNUM *primes[])
{
int pnum, i;
RSA_PRIME_INFO *pinfo;
if ((pnum = RSA_get_multi_prime_extra_count(r)) == 0)
return 0;
/*
* return other primes
* it's caller's responsibility to allocate oth_primes[pnum]
*/
for (i = 0; i < pnum; i++) {
pinfo = sk_RSA_PRIME_INFO_value(r->prime_infos, i);
primes[i] = pinfo->r;
}
return 1;
}
void RSA_get0_crt_params(const RSA *r,
const BIGNUM **dmp1, const BIGNUM **dmq1,
const BIGNUM **iqmp)
{
if (dmp1 != NULL)
*dmp1 = r->dmp1;
if (dmq1 != NULL)
*dmq1 = r->dmq1;
if (iqmp != NULL)
*iqmp = r->iqmp;
}
int RSA_get0_multi_prime_crt_params(const RSA *r, const BIGNUM *exps[],
const BIGNUM *coeffs[])
{
int pnum;
if ((pnum = RSA_get_multi_prime_extra_count(r)) == 0)
return 0;
/* return other primes */
if (exps != NULL || coeffs != NULL) {
RSA_PRIME_INFO *pinfo;
int i;
/* it's the user's job to guarantee the buffer length */
for (i = 0; i < pnum; i++) {
pinfo = sk_RSA_PRIME_INFO_value(r->prime_infos, i);
if (exps != NULL)
exps[i] = pinfo->d;
if (coeffs != NULL)
coeffs[i] = pinfo->t;
}
}
return 1;
}
void RSA_clear_flags(RSA *r, int flags)
{
r->flags &= ~flags;
}
int RSA_test_flags(const RSA *r, int flags)
{
return r->flags & flags;
}
void RSA_set_flags(RSA *r, int flags)
{
r->flags |= flags;
}
int RSA_get_version(RSA *r)
{
/* { two-prime(0), multi(1) } */
return r->version;
}
ENGINE *RSA_get0_engine(const RSA *r)
{
return r->engine;
}
int RSA_pkey_ctx_ctrl(EVP_PKEY_CTX *ctx, int optype, int cmd, int p1, void *p2)
{
/* If key type not RSA or RSA-PSS return error */
if (ctx != NULL && ctx->pmeth != NULL
&& ctx->pmeth->pkey_id != EVP_PKEY_RSA
&& ctx->pmeth->pkey_id != EVP_PKEY_RSA_PSS)
return -1;
return EVP_PKEY_CTX_ctrl(ctx, -1, optype, cmd, p1, p2);
}