/src/openssl/crypto/rsa/rsa_lib.c

Source
/*
 * Copyright 1995-2025 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/crypto.h>
#include <openssl/core_names.h>
#include <openssl/evp.h>
#include <openssl/param_build.h>
#include "internal/common.h"
#include "internal/cryptlib.h"
#include "internal/refcount.h"
#include "internal/zeroization.h"
#include "crypto/bn.h"
#include "crypto/evp.h"
#include "crypto/rsa.h"
#include "crypto/sparse_array.h"
#include "crypto/security_bits.h"
#include "rsa_local.h"

static RSA *rsa_new_intern(OSSL_LIB_CTX *libctx);

#ifndef FIPS_MODULE
RSA *RSA_new(void)
{
    return rsa_new_intern(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);
    rsa->meth = meth;
    if (meth->init)
        meth->init(rsa);
    return 1;
}

RSA *RSA_new_method(ENGINE *engine)
{
    if (!ossl_assert(engine == NULL))
        return NULL;
    return rsa_new_intern(NULL);
}
#endif

RSA *ossl_rsa_new_with_ctx(OSSL_LIB_CTX *libctx)
{
    return rsa_new_intern(libctx);
}

static RSA *rsa_new_intern(OSSL_LIB_CTX *libctx)
{
    RSA *ret = OPENSSL_zalloc(sizeof(*ret));

    if (ret == NULL)
        return NULL;

    ret->lock = CRYPTO_THREAD_lock_new();
    if (ret->lock == NULL) {
        ERR_raise(ERR_LIB_RSA, ERR_R_CRYPTO_LIB);
        OPENSSL_free(ret);
        return NULL;
    }

    if (!CRYPTO_NEW_REF(&ret->references, 1)) {
        CRYPTO_THREAD_lock_free(ret->lock);
        OPENSSL_free(ret);
        return NULL;
    }

    ret->blindings_sa = ossl_rsa_alloc_blinding();
    if (ret->blindings_sa == NULL)
        goto err;

    ret->libctx = libctx;
    ret->meth = RSA_get_default_method();
    ret->flags = ret->meth->flags & ~RSA_FLAG_NON_FIPS_ALLOW;
#ifndef FIPS_MODULE
    if (!CRYPTO_new_ex_data(CRYPTO_EX_INDEX_RSA, ret, &ret->ex_data)) {
        goto err;
    }
#endif

    if ((ret->meth->init != NULL) && !ret->meth->init(ret)) {
        ERR_raise(ERR_LIB_RSA, 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);
    REF_PRINT_COUNT("RSA", i, r);
    if (i > 0)
        return;
    REF_ASSERT_ISNT(i < 0);

    if (r->meth != NULL && r->meth->finish != NULL)
        r->meth->finish(r);

#ifndef FIPS_MODULE
    CRYPTO_free_ex_data(CRYPTO_EX_INDEX_RSA, r, &r->ex_data);
#endif

    CRYPTO_THREAD_lock_free(r->lock);
    CRYPTO_FREE_REF(&r->references);

    ossl_public_bn_free(r->n);
    ossl_public_bn_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);

#if defined(FIPS_MODULE) && !defined(OPENSSL_NO_ACVP_TESTS)
    ossl_rsa_acvp_test_free(r->acvp_test);
#endif

#ifndef FIPS_MODULE
    RSA_PSS_PARAMS_free(r->pss);
    sk_RSA_PRIME_INFO_pop_free(r->prime_infos, ossl_rsa_multip_info_free);
#endif
    ossl_rsa_free_blinding(r);
    OPENSSL_free(r);
}

int RSA_up_ref(RSA *r)
{
    int i;

    if (CRYPTO_UP_REF(&r->references, &i) <= 0)
        return 0;

    REF_PRINT_COUNT("RSA", i, r);
    REF_ASSERT_ISNT(i < 2);
    return i > 1 ? 1 : 0;
}

OSSL_LIB_CTX *ossl_rsa_get0_libctx(RSA *r)
{
    return r->libctx;
}

void ossl_rsa_set0_libctx(RSA *r, OSSL_LIB_CTX *libctx)
{
    r->libctx = libctx;
}

#ifndef FIPS_MODULE
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);
}
#endif

/*
 * Define a scaling constant for our fixed point arithmetic.
 * This value must be a power of two because the base two logarithm code
 * makes this assumption.  The exponent must also be a multiple of three so
 * that the scale factor has an exact cube root.  Finally, the scale factor
 * should not be so large that a multiplication of two scaled numbers
 * overflows a 64 bit unsigned integer.
 */
static const unsigned int scale = 1 << 18;
static const unsigned int cbrt_scale = 1 << (2 * 18 / 3);

/* Define some constants, none exceed 32 bits */
static const unsigned int log_2 = 0x02c5c8; /* scale * log(2) */
static const unsigned int log_e = 0x05c551; /* scale * log2(M_E) */
static const unsigned int c1_923 = 0x07b126; /* scale * 1.923 */
static const unsigned int c4_690 = 0x12c28f; /* scale * 4.690 */

/*
 * Multiply two scaled integers together and rescale the result.
 */
static ossl_inline uint64_t mul2(uint64_t a, uint64_t b)
{
    return a * b / scale;
}

/*
 * Calculate the cube root of a 64 bit scaled integer.
 * Although the cube root of a 64 bit number does fit into a 32 bit unsigned
 * integer, this is not guaranteed after scaling, so this function has a
 * 64 bit return.  This uses the shifting nth root algorithm with some
 * algebraic simplifications.
 */
static uint64_t icbrt64(uint64_t x)
{
    uint64_t r = 0;
    uint64_t b;
    int s;

    for (s = 63; s >= 0; s -= 3) {
        r <<= 1;
        b = 3 * r * (r + 1) + 1;
        if ((x >> s) >= b) {
            x -= b << s;
            r++;
        }
    }
    return r * cbrt_scale;
}

/*
 * Calculate the natural logarithm of a 64 bit scaled integer.
 * This is done by calculating a base two logarithm and scaling.
 * The maximum logarithm (base 2) is 64 and this reduces base e, so
 * a 32 bit result should not overflow.  The argument passed must be
 * greater than unity so we don't need to handle negative results.
 */
static uint32_t ilog_e(uint64_t v)
{
    uint32_t i, r = 0;

    /*
     * Scale down the value into the range 1 .. 2.
     *
     * If fractional numbers need to be processed, another loop needs
     * to go here that checks v < scale and if so multiplies it by 2 and
     * reduces r by scale.  This also means making r signed.
     */
    while (v >= 2 * scale) {
        v >>= 1;
        r += scale;
    }
    for (i = scale / 2; i != 0; i /= 2) {
        v = mul2(v, v);
        if (v >= 2 * scale) {
            v >>= 1;
            r += i;
        }
    }
    r = (r * (uint64_t)scale) / log_e;
    return r;
}

/*
 * NIST SP 800-56B rev 2 Appendix D: Maximum Security Strength Estimates for IFC
 * Modulus Lengths.
 *
 * Note that this formula is also referred to in SP800-56A rev3 Appendix D:
 * for FFC safe prime groups for modp and ffdhe.
 * After Table 25 and Table 26 it refers to
 * "The maximum security strength estimates were calculated using the formula in
 * Section 7.5 of the FIPS 140 IG and rounded to the nearest multiple of eight
 * bits".
 *
 * The formula is:
 *
 * E = \frac{1.923 \sqrt[3]{nBits \cdot log_e(2)}
 *           \cdot(log_e(nBits \cdot log_e(2))^{2/3} - 4.69}{log_e(2)}
 * The two cube roots are merged together here.
 */
uint16_t ossl_ifc_ffc_compute_security_bits(int n)
{
    uint64_t x;
    uint32_t lx;
    uint16_t y, cap;

    /*
     * Look for common values as listed in standards.
     * These values are not exactly equal to the results from the formulae in
     * the standards but are defined to be canonical.
     */
    switch (n) {
    case 2048: /* SP 800-56B rev 2 Appendix D and FIPS 140-2 IG 7.5 */
        return 112;
    case 3072: /* SP 800-56B rev 2 Appendix D and FIPS 140-2 IG 7.5 */
        return 128;
    case 4096: /* SP 800-56B rev 2 Appendix D */
        return 152;
    case 6144: /* SP 800-56B rev 2 Appendix D */
        return 176;
    case 7680: /* FIPS 140-2 IG 7.5 */
        return 192;
    case 8192: /* SP 800-56B rev 2 Appendix D */
        return 200;
    case 15360: /* FIPS 140-2 IG 7.5 */
        return 256;
    }

    /*
     * The first incorrect result (i.e. not accurate or off by one low) occurs
     * for n = 699668.  The true value here is 1200.  Instead of using this n
     * as the check threshold, the smallest n such that the correct result is
     * 1200 is used instead.
     */
    if (n >= 687737)
        return 1200;
    if (n < 8)
        return 0;

    /*
     * To ensure that the output is non-decreasing with respect to n,
     * a cap needs to be applied to the two values where the function over
     * estimates the strength (according to the above fast path).
     */
    if (n <= 7680)
        cap = 192;
    else if (n <= 15360)
        cap = 256;
    else
        cap = 1200;

    x = n * (uint64_t)log_2;
    lx = ilog_e(x);
    y = (uint16_t)((mul2(c1_923, icbrt64(mul2(mul2(x, lx), lx))) - c4_690)
        / log_2);
    y = (y + 4) & ~7;
    if (y > cap)
        y = cap;
    return y;
}

int RSA_security_bits(const RSA *rsa)
{
    int bits = BN_num_bits(rsa->n);

#ifndef FIPS_MODULE
    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) > ossl_rsa_multip_cap(bits))
            return 0;
    }
#endif
    return ossl_ifc_ffc_compute_security_bits(bits);
}

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) {
        ossl_public_bn_free(r->n);
        r->n = n;
    }
    if (e != NULL) {
        ossl_public_bn_free(r->e);
        r->e = e;
    }
    if (d != NULL) {
        BN_clear_free(r->d);
        r->d = d;
        BN_set_flags(r->d, BN_FLG_CONSTTIME);
    }
    r->dirty_cnt++;

    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_clear_free(r->p);
        r->p = p;
        BN_set_flags(r->p, BN_FLG_CONSTTIME);
    }
    if (q != NULL) {
        BN_clear_free(r->q);
        r->q = q;
        BN_set_flags(r->q, BN_FLG_CONSTTIME);
    }
    r->dirty_cnt++;

    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_clear_free(r->dmp1);
        r->dmp1 = dmp1;
        BN_set_flags(r->dmp1, BN_FLG_CONSTTIME);
    }
    if (dmq1 != NULL) {
        BN_clear_free(r->dmq1);
        r->dmq1 = dmq1;
        BN_set_flags(r->dmq1, BN_FLG_CONSTTIME);
    }
    if (iqmp != NULL) {
        BN_clear_free(r->iqmp);
        r->iqmp = iqmp;
        BN_set_flags(r->iqmp, BN_FLG_CONSTTIME);
    }
    r->dirty_cnt++;

    return 1;
}

#ifndef FIPS_MODULE
/*
 * 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 = ossl_rsa_multip_info_new();
        if (pinfo == NULL)
            goto err;
        if (primes[i] != NULL && exps[i] != NULL && coeffs[i] != NULL) {
            BN_clear_free(pinfo->r);
            BN_clear_free(pinfo->d);
            BN_clear_free(pinfo->t);
            pinfo->r = primes[i];
            pinfo->d = exps[i];
            pinfo->t = coeffs[i];
            BN_set_flags(pinfo->r, BN_FLG_CONSTTIME);
            BN_set_flags(pinfo->d, BN_FLG_CONSTTIME);
            BN_set_flags(pinfo->t, BN_FLG_CONSTTIME);
        } else {
            ossl_rsa_multip_info_free(pinfo);
            goto err;
        }
        (void)sk_RSA_PRIME_INFO_push(prime_infos, pinfo);
    }

    r->prime_infos = prime_infos;

    if (!ossl_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, ossl_rsa_multip_info_free);
    }

    r->version = RSA_ASN1_VERSION_MULTI;
    r->dirty_cnt++;

    return 1;
err:
    /* r, d, t should not be freed */
    sk_RSA_PRIME_INFO_pop_free(prime_infos, ossl_rsa_multip_info_free_ex);
    return 0;
}
#endif

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;
}

#ifndef FIPS_MODULE
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;
}
#endif

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;
}

#ifndef FIPS_MODULE
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;
}
#endif

const BIGNUM *RSA_get0_n(const RSA *r)
{
    return r->n;
}

const BIGNUM *RSA_get0_e(const RSA *r)
{
    return r->e;
}

const BIGNUM *RSA_get0_d(const RSA *r)
{
    return r->d;
}

const BIGNUM *RSA_get0_p(const RSA *r)
{
    return r->p;
}

const BIGNUM *RSA_get0_q(const RSA *r)
{
    return r->q;
}

const BIGNUM *RSA_get0_dmp1(const RSA *r)
{
    return r->dmp1;
}

const BIGNUM *RSA_get0_dmq1(const RSA *r)
{
    return r->dmq1;
}

const BIGNUM *RSA_get0_iqmp(const RSA *r)
{
    return r->iqmp;
}

const RSA_PSS_PARAMS *RSA_get0_pss_params(const RSA *r)
{
#ifdef FIPS_MODULE
    return NULL;
#else
    return r->pss;
#endif
}

/* Internal */
int ossl_rsa_set0_pss_params(RSA *r, RSA_PSS_PARAMS *pss)
{
#ifdef FIPS_MODULE
    return 0;
#else
    RSA_PSS_PARAMS_free(r->pss);
    r->pss = pss;
    return 1;
#endif
}

/* Internal */
RSA_PSS_PARAMS_30 *ossl_rsa_get0_pss_params_30(RSA *r)
{
    return &r->pss_params;
}

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;
}

#ifndef FIPS_MODULE
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->legacy_keytype != EVP_PKEY_RSA
            && ctx->legacy_keytype != EVP_PKEY_RSA_PSS))
        return -1;
    return EVP_PKEY_CTX_ctrl(ctx, -1, optype, cmd, p1, p2);
}
#endif

DEFINE_STACK_OF(BIGNUM)

/*
 * Note: This function deletes values from the parameter
 * stack values as they are consumed and set in the RSA key.
 */
int ossl_rsa_set0_all_params(RSA *r, STACK_OF(BIGNUM) *primes,
    STACK_OF(BIGNUM) *exps,
    STACK_OF(BIGNUM) *coeffs)
{
#ifndef FIPS_MODULE
    STACK_OF(RSA_PRIME_INFO) *prime_infos, *old_infos = NULL;
#endif
    int pnum;

    if (primes == NULL || exps == NULL || coeffs == NULL)
        return 0;

    pnum = sk_BIGNUM_num(primes);

    /* we need at least 2 primes */
    if (pnum < 2)
        return 0;

    if (!RSA_set0_factors(r, sk_BIGNUM_value(primes, 0),
            sk_BIGNUM_value(primes, 1)))
        return 0;

    /*
     * if we managed to set everything above, remove those elements from the
     * stack
     * Note, we do this after the above all to ensure that we have taken
     * ownership of all the elements in the RSA key to avoid memory leaks
     * we also use delete 0 here as we are grabbing items from the end of the
     * stack rather than the start, otherwise we could use pop
     */
    sk_BIGNUM_delete(primes, 0);
    sk_BIGNUM_delete(primes, 0);

    if (pnum == sk_BIGNUM_num(exps)
        && pnum == sk_BIGNUM_num(coeffs) + 1) {

        if (!RSA_set0_crt_params(r, sk_BIGNUM_value(exps, 0),
                sk_BIGNUM_value(exps, 1),
                sk_BIGNUM_value(coeffs, 0)))
            return 0;

        /* as above, once we consume the above params, delete them from the list */
        sk_BIGNUM_delete(exps, 0);
        sk_BIGNUM_delete(exps, 0);
        sk_BIGNUM_delete(coeffs, 0);
    }

#ifndef FIPS_MODULE
    old_infos = r->prime_infos;
#endif

    if (pnum > 2) {
#ifndef FIPS_MODULE
        int i;

        prime_infos = sk_RSA_PRIME_INFO_new_reserve(NULL, pnum);
        if (prime_infos == NULL)
            return 0;

        for (i = 2; i < pnum; i++) {
            BIGNUM *prime = sk_BIGNUM_pop(primes);
            BIGNUM *exp = sk_BIGNUM_pop(exps);
            BIGNUM *coeff = sk_BIGNUM_pop(coeffs);
            RSA_PRIME_INFO *pinfo = NULL;

            if (!ossl_assert(prime != NULL && exp != NULL && coeff != NULL))
                goto err;

            /* Using ossl_rsa_multip_info_new() is wasteful, so allocate directly */
            if ((pinfo = OPENSSL_zalloc(sizeof(*pinfo))) == NULL)
                goto err;

            pinfo->r = prime;
            pinfo->d = exp;
            pinfo->t = coeff;
            BN_set_flags(pinfo->r, BN_FLG_CONSTTIME);
            BN_set_flags(pinfo->d, BN_FLG_CONSTTIME);
            BN_set_flags(pinfo->t, BN_FLG_CONSTTIME);
            (void)sk_RSA_PRIME_INFO_push(prime_infos, pinfo);
        }

        r->prime_infos = prime_infos;

        if (!ossl_rsa_multip_calc_product(r)) {
            r->prime_infos = old_infos;
            goto err;
        }
#else
        return 0;
#endif
    }

#ifndef FIPS_MODULE
    if (old_infos != 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_infos, ossl_rsa_multip_info_free);
    }
#endif

    r->version = pnum > 2 ? RSA_ASN1_VERSION_MULTI : RSA_ASN1_VERSION_DEFAULT;
    r->dirty_cnt++;

    return 1;
#ifndef FIPS_MODULE
err:
    /* r, d, t should not be freed */
    sk_RSA_PRIME_INFO_pop_free(prime_infos, ossl_rsa_multip_info_free_ex);
    return 0;
#endif
}

DEFINE_SPECIAL_STACK_OF_CONST(BIGNUM_const, BIGNUM)

int ossl_rsa_get0_all_params(RSA *r, STACK_OF(BIGNUM_const) *primes,
    STACK_OF(BIGNUM_const) *exps,
    STACK_OF(BIGNUM_const) *coeffs)
{
#ifndef FIPS_MODULE
    RSA_PRIME_INFO *pinfo;
    int i, pnum;
#endif

    if (r == NULL)
        return 0;

    /* If |p| is NULL, there are no CRT parameters */
    if (RSA_get0_p(r) == NULL)
        return 1;

    sk_BIGNUM_const_push(primes, RSA_get0_p(r));
    sk_BIGNUM_const_push(primes, RSA_get0_q(r));
    sk_BIGNUM_const_push(exps, RSA_get0_dmp1(r));
    sk_BIGNUM_const_push(exps, RSA_get0_dmq1(r));
    sk_BIGNUM_const_push(coeffs, RSA_get0_iqmp(r));

#ifndef FIPS_MODULE
    pnum = RSA_get_multi_prime_extra_count(r);
    for (i = 0; i < pnum; i++) {
        pinfo = sk_RSA_PRIME_INFO_value(r->prime_infos, i);
        sk_BIGNUM_const_push(primes, pinfo->r);
        sk_BIGNUM_const_push(exps, pinfo->d);
        sk_BIGNUM_const_push(coeffs, pinfo->t);
    }
#endif

    return 1;
}

#define safe_BN_num_bits(_k_) (((_k_) == NULL) ? 0 : BN_num_bits((_k_)))
int ossl_rsa_check_factors(RSA *r)
{
    int valid = 0;
    int n, i, bits;
    STACK_OF(BIGNUM_const) *factors = sk_BIGNUM_const_new_null();
    STACK_OF(BIGNUM_const) *exps = sk_BIGNUM_const_new_null();
    STACK_OF(BIGNUM_const) *coeffs = sk_BIGNUM_const_new_null();

    if (factors == NULL || exps == NULL || coeffs == NULL)
        goto done;

    /*
     * Simple sanity check for RSA key. All RSA key parameters
     * must be less-than/equal-to RSA parameter n.
     */
    ossl_rsa_get0_all_params(r, factors, exps, coeffs);
    n = safe_BN_num_bits(RSA_get0_n(r));

    if (safe_BN_num_bits(RSA_get0_d(r)) > n)
        goto done;

    for (i = 0; i < sk_BIGNUM_const_num(exps); i++) {
        bits = safe_BN_num_bits(sk_BIGNUM_const_value(exps, i));
        if (bits > n)
            goto done;
    }

    for (i = 0; i < sk_BIGNUM_const_num(factors); i++) {
        bits = safe_BN_num_bits(sk_BIGNUM_const_value(factors, i));
        if (bits > n)
            goto done;
    }

    for (i = 0; i < sk_BIGNUM_const_num(coeffs); i++) {
        bits = safe_BN_num_bits(sk_BIGNUM_const_value(coeffs, i));
        if (bits > n)
            goto done;
    }

    valid = 1;

done:
    sk_BIGNUM_const_free(factors);
    sk_BIGNUM_const_free(exps);
    sk_BIGNUM_const_free(coeffs);

    return valid;
}

#ifndef FIPS_MODULE
/* Helpers to set or get diverse hash algorithm names */
static int int_set_rsa_md_name(EVP_PKEY_CTX *ctx,
    /* For checks */
    int keytype, int optype,
    /* For EVP_PKEY_CTX_set_params() */
    const char *mdkey, const char *mdname,
    const char *propkey, const char *mdprops)
{
    OSSL_PARAM params[3], *p = params;

    if (ctx == NULL || mdname == NULL || (ctx->operation & optype) == 0) {
        ERR_raise(ERR_LIB_EVP, EVP_R_COMMAND_NOT_SUPPORTED);
        /* Uses the same return values as EVP_PKEY_CTX_ctrl */
        return -2;
    }

    /* If key type not RSA return error */
    switch (keytype) {
    case -1:
        if (!EVP_PKEY_CTX_is_a(ctx, "RSA")
            && !EVP_PKEY_CTX_is_a(ctx, "RSA-PSS"))
            return -1;
        break;
    default:
        if (!EVP_PKEY_CTX_is_a(ctx, evp_pkey_type2name(keytype)))
            return -1;
        break;
    }

    /* Cast away the const. This is read only so should be safe */
    *p++ = OSSL_PARAM_construct_utf8_string(mdkey, (char *)mdname, 0);
    if (evp_pkey_ctx_is_provided(ctx) && mdprops != NULL) {
        /* Cast away the const. This is read only so should be safe */
        *p++ = OSSL_PARAM_construct_utf8_string(propkey, (char *)mdprops, 0);
    }
    *p++ = OSSL_PARAM_construct_end();

    return evp_pkey_ctx_set_params_strict(ctx, params);
}

/* Helpers to set or get diverse hash algorithm names */
static int int_get_rsa_md_name(EVP_PKEY_CTX *ctx,
    /* For checks */
    int keytype, int optype,
    /* For EVP_PKEY_CTX_get_params() */
    const char *mdkey,
    char *mdname, size_t mdnamesize)
{
    OSSL_PARAM params[2], *p = params;

    if (ctx == NULL || mdname == NULL || (ctx->operation & optype) == 0) {
        ERR_raise(ERR_LIB_EVP, EVP_R_COMMAND_NOT_SUPPORTED);
        /* Uses the same return values as EVP_PKEY_CTX_ctrl */
        return -2;
    }

    /* If key type not RSA return error */
    switch (keytype) {
    case -1:
        if (!EVP_PKEY_CTX_is_a(ctx, "RSA")
            && !EVP_PKEY_CTX_is_a(ctx, "RSA-PSS"))
            return -1;
        break;
    default:
        if (!EVP_PKEY_CTX_is_a(ctx, evp_pkey_type2name(keytype)))
            return -1;
        break;
    }

    /* Cast away the const. This is read only so should be safe */
    *p++ = OSSL_PARAM_construct_utf8_string(mdkey, (char *)mdname, mdnamesize);
    *p++ = OSSL_PARAM_construct_end();

    return evp_pkey_ctx_get_params_strict(ctx, params);
}

/*
 * This one is currently implemented as an EVP_PKEY_CTX_ctrl() wrapper,
 * simply because that's easier.
 */
int EVP_PKEY_CTX_set_rsa_padding(EVP_PKEY_CTX *ctx, int pad_mode)
{
    return RSA_pkey_ctx_ctrl(ctx, -1, EVP_PKEY_CTRL_RSA_PADDING,
        pad_mode, NULL);
}

/*
 * This one is currently implemented as an EVP_PKEY_CTX_ctrl() wrapper,
 * simply because that's easier.
 */
int EVP_PKEY_CTX_get_rsa_padding(EVP_PKEY_CTX *ctx, int *pad_mode)
{
    return RSA_pkey_ctx_ctrl(ctx, -1, EVP_PKEY_CTRL_GET_RSA_PADDING,
        0, pad_mode);
}

/*
 * This one is currently implemented as an EVP_PKEY_CTX_ctrl() wrapper,
 * simply because that's easier.
 */
int EVP_PKEY_CTX_set_rsa_pss_keygen_md(EVP_PKEY_CTX *ctx, const EVP_MD *md)
{
    return EVP_PKEY_CTX_ctrl(ctx, EVP_PKEY_RSA_PSS, EVP_PKEY_OP_KEYGEN,
        EVP_PKEY_CTRL_MD, 0, (void *)(md));
}

int EVP_PKEY_CTX_set_rsa_pss_keygen_md_name(EVP_PKEY_CTX *ctx,
    const char *mdname,
    const char *mdprops)
{
    return int_set_rsa_md_name(ctx, EVP_PKEY_RSA_PSS, EVP_PKEY_OP_KEYGEN,
        OSSL_PKEY_PARAM_RSA_DIGEST, mdname,
        OSSL_PKEY_PARAM_RSA_DIGEST_PROPS, mdprops);
}

/*
 * This one is currently implemented as an EVP_PKEY_CTX_ctrl() wrapper,
 * simply because that's easier.
 */
int EVP_PKEY_CTX_set_rsa_oaep_md(EVP_PKEY_CTX *ctx, const EVP_MD *md)
{
    /* If key type not RSA return error */
    if (!EVP_PKEY_CTX_is_a(ctx, "RSA"))
        return -1;

    return EVP_PKEY_CTX_ctrl(ctx, EVP_PKEY_RSA, EVP_PKEY_OP_TYPE_CRYPT,
        EVP_PKEY_CTRL_RSA_OAEP_MD, 0, (void *)(md));
}

int EVP_PKEY_CTX_set_rsa_oaep_md_name(EVP_PKEY_CTX *ctx, const char *mdname,
    const char *mdprops)
{
    return int_set_rsa_md_name(ctx, EVP_PKEY_RSA, EVP_PKEY_OP_TYPE_CRYPT,
        OSSL_ASYM_CIPHER_PARAM_OAEP_DIGEST, mdname,
        OSSL_ASYM_CIPHER_PARAM_OAEP_DIGEST_PROPS, mdprops);
}

int EVP_PKEY_CTX_get_rsa_oaep_md_name(EVP_PKEY_CTX *ctx, char *name,
    size_t namesize)
{
    return int_get_rsa_md_name(ctx, EVP_PKEY_RSA, EVP_PKEY_OP_TYPE_CRYPT,
        OSSL_ASYM_CIPHER_PARAM_OAEP_DIGEST,
        name, namesize);
}

/*
 * This one is currently implemented as an EVP_PKEY_CTX_ctrl() wrapper,
 * simply because that's easier.
 */
int EVP_PKEY_CTX_get_rsa_oaep_md(EVP_PKEY_CTX *ctx, const EVP_MD **md)
{
    /* If key type not RSA return error */
    if (!EVP_PKEY_CTX_is_a(ctx, "RSA"))
        return -1;

    return EVP_PKEY_CTX_ctrl(ctx, EVP_PKEY_RSA, EVP_PKEY_OP_TYPE_CRYPT,
        EVP_PKEY_CTRL_GET_RSA_OAEP_MD, 0, (void *)md);
}

/*
 * This one is currently implemented as an EVP_PKEY_CTX_ctrl() wrapper,
 * simply because that's easier.
 */
int EVP_PKEY_CTX_set_rsa_mgf1_md(EVP_PKEY_CTX *ctx, const EVP_MD *md)
{
    return RSA_pkey_ctx_ctrl(ctx, EVP_PKEY_OP_TYPE_SIG | EVP_PKEY_OP_TYPE_CRYPT,
        EVP_PKEY_CTRL_RSA_MGF1_MD, 0, (void *)(md));
}

int EVP_PKEY_CTX_set_rsa_mgf1_md_name(EVP_PKEY_CTX *ctx, const char *mdname,
    const char *mdprops)
{
    return int_set_rsa_md_name(ctx, -1,
        EVP_PKEY_OP_TYPE_CRYPT | EVP_PKEY_OP_TYPE_SIG,
        OSSL_PKEY_PARAM_MGF1_DIGEST, mdname,
        OSSL_PKEY_PARAM_MGF1_PROPERTIES, mdprops);
}

int EVP_PKEY_CTX_get_rsa_mgf1_md_name(EVP_PKEY_CTX *ctx, char *name,
    size_t namesize)
{
    return int_get_rsa_md_name(ctx, -1,
        EVP_PKEY_OP_TYPE_CRYPT | EVP_PKEY_OP_TYPE_SIG,
        OSSL_PKEY_PARAM_MGF1_DIGEST, name, namesize);
}

/*
 * This one is currently implemented as an EVP_PKEY_CTX_ctrl() wrapper,
 * simply because that's easier.
 */
int EVP_PKEY_CTX_set_rsa_pss_keygen_mgf1_md(EVP_PKEY_CTX *ctx, const EVP_MD *md)
{
    return EVP_PKEY_CTX_ctrl(ctx, EVP_PKEY_RSA_PSS, EVP_PKEY_OP_KEYGEN,
        EVP_PKEY_CTRL_RSA_MGF1_MD, 0, (void *)(md));
}

int EVP_PKEY_CTX_set_rsa_pss_keygen_mgf1_md_name(EVP_PKEY_CTX *ctx,
    const char *mdname)
{
    return int_set_rsa_md_name(ctx, EVP_PKEY_RSA_PSS, EVP_PKEY_OP_KEYGEN,
        OSSL_PKEY_PARAM_MGF1_DIGEST, mdname,
        NULL, NULL);
}

/*
 * This one is currently implemented as an EVP_PKEY_CTX_ctrl() wrapper,
 * simply because that's easier.
 */
int EVP_PKEY_CTX_get_rsa_mgf1_md(EVP_PKEY_CTX *ctx, const EVP_MD **md)
{
    return RSA_pkey_ctx_ctrl(ctx, EVP_PKEY_OP_TYPE_SIG | EVP_PKEY_OP_TYPE_CRYPT,
        EVP_PKEY_CTRL_GET_RSA_MGF1_MD, 0, (void *)(md));
}

int EVP_PKEY_CTX_set0_rsa_oaep_label(EVP_PKEY_CTX *ctx, void *label, int llen)
{
    OSSL_PARAM rsa_params[2], *p = rsa_params;
    const char *empty = "";
    /*
     * Needed as we swap label with empty if it is NULL, and label is
     * freed at the end of this function.
     */
    void *plabel = label;
    int ret;

    if (ctx == NULL || !EVP_PKEY_CTX_IS_ASYM_CIPHER_OP(ctx)) {
        ERR_raise(ERR_LIB_EVP, EVP_R_COMMAND_NOT_SUPPORTED);
        /* Uses the same return values as EVP_PKEY_CTX_ctrl */
        return -2;
    }

    /* If key type not RSA return error */
    if (!EVP_PKEY_CTX_is_a(ctx, "RSA"))
        return -1;

    /* Accept NULL for backward compatibility */
    if (label == NULL && llen == 0)
        plabel = (void *)empty;

    /* Cast away the const. This is read only so should be safe */
    *p++ = OSSL_PARAM_construct_octet_string(OSSL_ASYM_CIPHER_PARAM_OAEP_LABEL,
        (void *)plabel, (size_t)llen);
    *p++ = OSSL_PARAM_construct_end();

    ret = evp_pkey_ctx_set_params_strict(ctx, rsa_params);
    if (ret <= 0)
        return ret;

    /* Ownership is supposed to be transferred to the callee. */
    OPENSSL_free(label);
    return 1;
}

int EVP_PKEY_CTX_get0_rsa_oaep_label(EVP_PKEY_CTX *ctx, unsigned char **label)
{
    OSSL_PARAM rsa_params[2], *p = rsa_params;
    size_t labellen;

    if (ctx == NULL || !EVP_PKEY_CTX_IS_ASYM_CIPHER_OP(ctx)) {
        ERR_raise(ERR_LIB_EVP, EVP_R_COMMAND_NOT_SUPPORTED);
        /* Uses the same return values as EVP_PKEY_CTX_ctrl */
        return -2;
    }

    /* If key type not RSA return error */
    if (!EVP_PKEY_CTX_is_a(ctx, "RSA"))
        return -1;

    *p++ = OSSL_PARAM_construct_octet_ptr(OSSL_ASYM_CIPHER_PARAM_OAEP_LABEL,
        (void **)label, 0);
    *p++ = OSSL_PARAM_construct_end();

    if (!EVP_PKEY_CTX_get_params(ctx, rsa_params))
        return -1;

    labellen = rsa_params[0].return_size;
    if (labellen > INT_MAX)
        return -1;

    return (int)labellen;
}

/*
 * This one is currently implemented as an EVP_PKEY_CTX_ctrl() wrapper,
 * simply because that's easier.
 */
int EVP_PKEY_CTX_set_rsa_pss_saltlen(EVP_PKEY_CTX *ctx, int saltlen)
{
    /*
     * For some reason, the optype was set to this:
     *
     * EVP_PKEY_OP_SIGN|EVP_PKEY_OP_VERIFY
     *
     * However, we do use RSA-PSS with the whole gamut of diverse signature
     * and verification operations, so the optype gets upgraded to this:
     *
     * EVP_PKEY_OP_TYPE_SIG
     */
    return RSA_pkey_ctx_ctrl(ctx, EVP_PKEY_OP_TYPE_SIG,
        EVP_PKEY_CTRL_RSA_PSS_SALTLEN, saltlen, NULL);
}

/*
 * This one is currently implemented as an EVP_PKEY_CTX_ctrl() wrapper,
 * simply because that's easier.
 */
int EVP_PKEY_CTX_get_rsa_pss_saltlen(EVP_PKEY_CTX *ctx, int *saltlen)
{
    /*
     * Because of circumstances, the optype is updated from:
     *
     * EVP_PKEY_OP_SIGN|EVP_PKEY_OP_VERIFY
     *
     * to:
     *
     * EVP_PKEY_OP_TYPE_SIG
     */
    return RSA_pkey_ctx_ctrl(ctx, EVP_PKEY_OP_TYPE_SIG,
        EVP_PKEY_CTRL_GET_RSA_PSS_SALTLEN, 0, saltlen);
}

int EVP_PKEY_CTX_set_rsa_pss_keygen_saltlen(EVP_PKEY_CTX *ctx, int saltlen)
{
    OSSL_PARAM pad_params[2], *p = pad_params;

    if (ctx == NULL || !EVP_PKEY_CTX_IS_GEN_OP(ctx)) {
        ERR_raise(ERR_LIB_EVP, EVP_R_COMMAND_NOT_SUPPORTED);
        /* Uses the same return values as EVP_PKEY_CTX_ctrl */
        return -2;
    }

    if (!EVP_PKEY_CTX_is_a(ctx, "RSA-PSS"))
        return -1;

    *p++ = OSSL_PARAM_construct_int(OSSL_SIGNATURE_PARAM_PSS_SALTLEN,
        &saltlen);
    *p++ = OSSL_PARAM_construct_end();

    return evp_pkey_ctx_set_params_strict(ctx, pad_params);
}

int EVP_PKEY_CTX_set_rsa_keygen_bits(EVP_PKEY_CTX *ctx, int bits)
{
    OSSL_PARAM params[2], *p = params;
    size_t bits2 = bits;

    if (ctx == NULL || !EVP_PKEY_CTX_IS_GEN_OP(ctx)) {
        ERR_raise(ERR_LIB_EVP, EVP_R_COMMAND_NOT_SUPPORTED);
        /* Uses the same return values as EVP_PKEY_CTX_ctrl */
        return -2;
    }

    /* If key type not RSA return error */
    if (!EVP_PKEY_CTX_is_a(ctx, "RSA")
        && !EVP_PKEY_CTX_is_a(ctx, "RSA-PSS"))
        return -1;

    *p++ = OSSL_PARAM_construct_size_t(OSSL_PKEY_PARAM_RSA_BITS, &bits2);
    *p++ = OSSL_PARAM_construct_end();

    return evp_pkey_ctx_set_params_strict(ctx, params);
}

int EVP_PKEY_CTX_set_rsa_keygen_pubexp(EVP_PKEY_CTX *ctx, BIGNUM *pubexp)
{
    int ret = RSA_pkey_ctx_ctrl(ctx, EVP_PKEY_OP_KEYGEN,
        EVP_PKEY_CTRL_RSA_KEYGEN_PUBEXP, 0, pubexp);

    /*
     * Satisfy memory semantics for pre-3.0 callers of
     * EVP_PKEY_CTX_set_rsa_keygen_pubexp(): their expectation is that input
     * pubexp BIGNUM becomes managed by the EVP_PKEY_CTX on success.
     */
    if (ret > 0 && evp_pkey_ctx_is_provided(ctx)) {
        BN_free(ctx->rsa_pubexp);
        ctx->rsa_pubexp = pubexp;
    }

    return ret;
}

int EVP_PKEY_CTX_set1_rsa_keygen_pubexp(EVP_PKEY_CTX *ctx, BIGNUM *pubexp)
{
    int ret = 0;

    /*
     * When we're dealing with a provider, there's no need to duplicate
     * pubexp, as it gets copied when transforming to an OSSL_PARAM anyway.
     */
    if (evp_pkey_ctx_is_legacy(ctx)) {
        pubexp = BN_dup(pubexp);
        if (pubexp == NULL)
            return 0;
    }
    ret = EVP_PKEY_CTX_ctrl(ctx, EVP_PKEY_RSA, EVP_PKEY_OP_KEYGEN,
        EVP_PKEY_CTRL_RSA_KEYGEN_PUBEXP, 0, pubexp);
    if (evp_pkey_ctx_is_legacy(ctx) && ret <= 0)
        BN_free(pubexp);
    return ret;
}

int EVP_PKEY_CTX_set_rsa_keygen_primes(EVP_PKEY_CTX *ctx, int primes)
{
    OSSL_PARAM params[2], *p = params;
    size_t primes2 = primes;

    if (ctx == NULL || !EVP_PKEY_CTX_IS_GEN_OP(ctx)) {
        ERR_raise(ERR_LIB_EVP, EVP_R_COMMAND_NOT_SUPPORTED);
        /* Uses the same return values as EVP_PKEY_CTX_ctrl */
        return -2;
    }

    /* If key type not RSA return error */
    if (!EVP_PKEY_CTX_is_a(ctx, "RSA")
        && !EVP_PKEY_CTX_is_a(ctx, "RSA-PSS"))
        return -1;

    *p++ = OSSL_PARAM_construct_size_t(OSSL_PKEY_PARAM_RSA_PRIMES, &primes2);
    *p++ = OSSL_PARAM_construct_end();

    return evp_pkey_ctx_set_params_strict(ctx, params);
}

#endif

Coverage Report

Created: 2026-06-18 06:34