Modify DSA and DH keys to use a shared FFC_PARAMS struct

This is required in order to share code for FIPS related parameter generation and validation routinues.
Note the 'counter' field is now stored as a integer (as that is the form required for generation/validation functions).

Reviewed-by: Matt Caswell <matt@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/10860)

20 files changed, 464 insertions, 375 deletions

diff --git a/crypto/build.info b/crypto/build.info
index daa26b8ed4..6906c54db2 100644
--- a/crypto/build.info
+++ b/crypto/build.info
@@ -5,7 +5,8 @@ SUBDIRS=objects buffer bio stack lhash rand evp asn1 pem x509 conf \
         md2 md4 md5 sha mdc2 hmac ripemd whrlpool poly1305 \
         siphash sm3 des aes rc2 rc4 rc5 idea aria bf cast camellia \
         seed sm4 chacha modes bn ec rsa dsa dh sm2 dso engine \
-        err comp ocsp cms ts srp cmac ct async ess crmf cmp serializer
+        err comp ocsp cms ts srp cmac ct async ess crmf cmp serializer \
+        ffc
 
 LIBS=../libcrypto
 
diff --git a/crypto/dh/dh_ameth.c b/crypto/dh/dh_ameth.c
index 174bd04cef..fd241831dc 100644
--- a/crypto/dh/dh_ameth.c
+++ b/crypto/dh/dh_ameth.c
@@ -282,7 +282,7 @@ static int do_dh_print(BIO *bp, const DH *x, int indent, int ptype)
     else
         pub_key = NULL;
 
-    if (x->p == NULL || (ptype == 2 && priv_key == NULL)
+    if (x->params.p == NULL || (ptype == 2 && priv_key == NULL)
             || (ptype > 0 && pub_key == NULL)) {
         reason = ERR_R_PASSED_NULL_PARAMETER;
         goto err;
@@ -296,7 +296,7 @@ static int do_dh_print(BIO *bp, const DH *x, int indent, int ptype)
         ktype = "DH Parameters";
 
     if (!BIO_indent(bp, indent, 128)
-            || BIO_printf(bp, "%s: (%d bit)\n", ktype, BN_num_bits(x->p)) <= 0)
+            || BIO_printf(bp, "%s: (%d bit)\n", ktype, DH_bits(x)) <= 0)
         goto err;
     indent += 4;
 
@@ -305,35 +305,9 @@ static int do_dh_print(BIO *bp, const DH *x, int indent, int ptype)
     if (!ASN1_bn_print(bp, "public-key:", pub_key, NULL, indent))
         goto err;
 
-    if (!ASN1_bn_print(bp, "prime:", x->p, NULL, indent))
+    if (!ffc_params_print(bp, &x->params, indent))
         goto err;
-    if (!ASN1_bn_print(bp, "generator:", x->g, NULL, indent))
-        goto err;
-    if (x->q && !ASN1_bn_print(bp, "subgroup order:", x->q, NULL, indent))
-        goto err;
-    if (x->j && !ASN1_bn_print(bp, "subgroup factor:", x->j, NULL, indent))
-        goto err;
-    if (x->seed) {
-        int i;
 
-        if (!BIO_indent(bp, indent, 128)
-                || BIO_puts(bp, "seed:") <= 0)
-            goto err;
-        for (i = 0; i < x->seedlen; i++) {
-            if ((i % 15) == 0) {
-                if (BIO_puts(bp, "\n") <= 0
-                    || !BIO_indent(bp, indent + 4, 128))
-                    goto err;
-            }
-            if (BIO_printf(bp, "%02x%s", x->seed[i],
-                           ((i + 1) == x->seedlen) ? "" : ":") <= 0)
-                goto err;
-        }
-        if (BIO_write(bp, "\n", 1) <= 0)
-            return 0;
-    }
-    if (x->counter && !ASN1_bn_print(bp, "counter:", x->counter, NULL, indent))
-        goto err;
     if (x->length != 0) {
         if (!BIO_indent(bp, indent, 128)
                 || BIO_printf(bp, "recommended-private-length: %d bits\n",
@@ -355,7 +329,7 @@ static int int_dh_size(const EVP_PKEY *pkey)
 
 static int dh_bits(const EVP_PKEY *pkey)
 {
-    return BN_num_bits(pkey->pkey.dh->p);
+    return DH_bits(pkey->pkey.dh);
 }
 
 static int dh_security_bits(const EVP_PKEY *pkey)
@@ -365,59 +339,17 @@ static int dh_security_bits(const EVP_PKEY *pkey)
 
 static int dh_cmp_parameters(const EVP_PKEY *a, const EVP_PKEY *b)
 {
-    if (BN_cmp(a->pkey.dh->p, b->pkey.dh->p) ||
-        BN_cmp(a->pkey.dh->g, b->pkey.dh->g))
-        return 0;
-    else if (a->ameth == &dhx_asn1_meth) {
-        if (BN_cmp(a->pkey.dh->q, b->pkey.dh->q))
-            return 0;
-    }
-    return 1;
-}
-
-static int int_dh_bn_cpy(BIGNUM **dst, const BIGNUM *src)
-{
-    BIGNUM *a;
-
-    /*
-     * If source is read only just copy the pointer, so
-     * we don't have to reallocate it.
-     */
-    if (src == NULL)
-        a = NULL;
-    else if (BN_get_flags(src, BN_FLG_STATIC_DATA)
-                && !BN_get_flags(src, BN_FLG_MALLOCED))
-        a = (BIGNUM *)src;
-    else if ((a = BN_dup(src)) == NULL)
-        return 0;
-    BN_clear_free(*dst);
-    *dst = a;
-    return 1;
+    return ffc_params_cmp(&a->pkey.dh->params, &a->pkey.dh->params,
+                          a->ameth != &dhx_asn1_meth);
 }
 
 static int int_dh_param_copy(DH *to, const DH *from, int is_x942)
 {
     if (is_x942 == -1)
-        is_x942 = ! !from->q;
-    if (!int_dh_bn_cpy(&to->p, from->p))
+        is_x942 = (from->params.q != NULL);
+    if (!ffc_params_copy(&to->params, &from->params))
         return 0;
-    if (!int_dh_bn_cpy(&to->g, from->g))
-        return 0;
-    if (is_x942) {
-        if (!int_dh_bn_cpy(&to->q, from->q))
-            return 0;
-        if (!int_dh_bn_cpy(&to->j, from->j))
-            return 0;
-        OPENSSL_free(to->seed);
-        to->seed = NULL;
-        to->seedlen = 0;
-        if (from->seed) {
-            to->seed = OPENSSL_memdup(from->seed, from->seedlen);
-            if (!to->seed)
-                return 0;
-            to->seedlen = from->seedlen;
-        }
-    } else
+    if (!is_x942)
         to->length = from->length;
     to->dirty_cnt++;
     return 1;
@@ -449,9 +381,9 @@ static int dh_copy_parameters(EVP_PKEY *to, const EVP_PKEY *from)
 
 static int dh_missing_parameters(const EVP_PKEY *a)
 {
-    if (a->pkey.dh == NULL || a->pkey.dh->p == NULL || a->pkey.dh->g == NULL)
-        return 1;
-    return 0;
+    return a->pkey.dh == NULL
+        || a->pkey.dh->params.p == NULL
+        || a->pkey.dh->params.g == NULL;
 }
 
 static int dh_pub_cmp(const EVP_PKEY *a, const EVP_PKEY *b)
@@ -820,6 +752,7 @@ static int dh_cms_set_shared_info(EVP_PKEY_CTX *pctx, CMS_RecipientInfo *ri)
 static int dh_cms_decrypt(CMS_RecipientInfo *ri)
 {
     EVP_PKEY_CTX *pctx;
+
     pctx = CMS_RecipientInfo_get0_pkey_ctx(ri);
 
     if (pctx == NULL)
diff --git a/crypto/dh/dh_asn1.c b/crypto/dh/dh_asn1.c
index 2708a81cd0..75f2dd5bde 100644
--- a/crypto/dh/dh_asn1.c
+++ b/crypto/dh/dh_asn1.c
@@ -34,8 +34,8 @@ static int dh_cb(int operation, ASN1_VALUE **pval, const ASN1_ITEM *it,
 }
 
 ASN1_SEQUENCE_cb(DHparams, dh_cb) = {
-        ASN1_SIMPLE(DH, p, BIGNUM),
-        ASN1_SIMPLE(DH, g, BIGNUM),
+        ASN1_SIMPLE(DH, params.p, BIGNUM),
+        ASN1_SIMPLE(DH, params.g, BIGNUM),
         ASN1_OPT_EMBED(DH, length, ZINT32),
 } ASN1_SEQUENCE_END_cb(DH, DHparams)
 
@@ -82,6 +82,7 @@ IMPLEMENT_ASN1_ENCODE_FUNCTIONS_fname(int_dhx942_dh, DHxparams, int_dhx)
 
 DH *d2i_DHxparams(DH **a, const unsigned char **pp, long length)
 {
+    FFC_PARAMS *params;
     int_dhx942_dh *dhx = NULL;
     DH *dh = NULL;
     dh = DH_new();
@@ -93,22 +94,22 @@ DH *d2i_DHxparams(DH **a, const unsigned char **pp, long length)
         return NULL;
     }
 
-    if (a) {
+    if (a != NULL) {
         DH_free(*a);
         *a = dh;
     }
 
-    dh->p = dhx->p;
-    dh->q = dhx->q;
-    dh->g = dhx->g;
-    dh->j = dhx->j;
+    params = &dh->params;
+    ffc_params_set0_pqg(params, dhx->p, dhx->q, dhx->g);
+    ffc_params_set0_j(params, dhx->j);
 
-    if (dhx->vparams) {
-        dh->seed = dhx->vparams->seed->data;
-        dh->seedlen = dhx->vparams->seed->length;
-        dh->counter = dhx->vparams->counter;
-        dhx->vparams->seed->data = NULL;
+    if (dhx->vparams != NULL) {
+        /* The counter has a maximum value of 4 * numbits(p) - 1 */
+        size_t counter = (size_t)BN_get_word(dhx->vparams->counter);
+        ffc_params_set_validate_params(params, dhx->vparams->seed->data,
+                                       dhx->vparams->seed->length, counter);
         ASN1_BIT_STRING_free(dhx->vparams->seed);
+        BN_free(dhx->vparams->counter);
         OPENSSL_free(dhx->vparams);
         dhx->vparams = NULL;
     }
@@ -119,22 +120,34 @@ DH *d2i_DHxparams(DH **a, const unsigned char **pp, long length)
 
 int i2d_DHxparams(const DH *dh, unsigned char **pp)
 {
+    int ret = 0;
     int_dhx942_dh dhx;
-    int_dhvparams dhv;
-    ASN1_BIT_STRING bs;
-    dhx.p = dh->p;
-    dhx.g = dh->g;
-    dhx.q = dh->q;
-    dhx.j = dh->j;
-    if (dh->counter && dh->seed && dh->seedlen > 0) {
-        bs.flags = ASN1_STRING_FLAG_BITS_LEFT;
-        bs.data = dh->seed;
-        bs.length = dh->seedlen;
-        dhv.seed = &bs;
-        dhv.counter = dh->counter;
+    int_dhvparams dhv = { NULL, NULL };
+    ASN1_BIT_STRING seed;
+    size_t seedlen = 0;
+    const FFC_PARAMS *params = &dh->params;
+    int counter;
+
+    ffc_params_get0_pqg(params, (const BIGNUM **)&dhx.p,
+                        (const BIGNUM **)&dhx.q, (const BIGNUM **)&dhx.g);
+    dhx.j = params->j;
+    ffc_params_get_validate_params(params, &seed.data, &seedlen, &counter);
+    seed.length = (int)seedlen;
+
+    if (counter != -1 && seed.data != NULL && seed.length > 0) {
+        seed.flags = ASN1_STRING_FLAG_BITS_LEFT;
+        dhv.seed = &seed;
+        dhv.counter = BN_new();
+        if (dhv.counter == NULL)
+            return 0;
+        if (!BN_set_word(dhv.counter, (BN_ULONG)counter))
+            goto err;
         dhx.vparams = &dhv;
-    } else
+    } else {
         dhx.vparams = NULL;
-
-    return i2d_int_dhx(&dhx, pp);
+    }
+    ret = i2d_int_dhx(&dhx, pp);
+err:
+    BN_free(dhv.counter);
+    return ret;
 }
diff --git a/crypto/dh/dh_check.c b/crypto/dh/dh_check.c
index 70f083603f..8bb245207b 100644
--- a/crypto/dh/dh_check.c
+++ b/crypto/dh/dh_check.c
@@ -52,17 +52,19 @@ int DH_check_params(const DH *dh, int *ret)
     if (tmp == NULL)
         goto err;
 
-    if (!BN_is_odd(dh->p))
+    if (!BN_is_odd(dh->params.p))
         *ret |= DH_CHECK_P_NOT_PRIME;
-    if (BN_is_negative(dh->g) || BN_is_zero(dh->g) || BN_is_one(dh->g))
+    if (BN_is_negative(dh->params.g)
+        || BN_is_zero(dh->params.g)
+        || BN_is_one(dh->params.g))
         *ret |= DH_NOT_SUITABLE_GENERATOR;
-    if (BN_copy(tmp, dh->p) == NULL || !BN_sub_word(tmp, 1))
+    if (BN_copy(tmp, dh->params.p) == NULL || !BN_sub_word(tmp, 1))
         goto err;
-    if (BN_cmp(dh->g, tmp) >= 0)
+    if (BN_cmp(dh->params.g, tmp) >= 0)
         *ret |= DH_NOT_SUITABLE_GENERATOR;
-    if (BN_num_bits(dh->p) < DH_MIN_MODULUS_BITS)
+    if (BN_num_bits(dh->params.p) < DH_MIN_MODULUS_BITS)
         *ret |= DH_MODULUS_TOO_SMALL;
-    if (BN_num_bits(dh->p) > OPENSSL_DH_MAX_MODULUS_BITS)
+    if (BN_num_bits(dh->params.p) > OPENSSL_DH_MAX_MODULUS_BITS)
         *ret |= DH_MODULUS_TOO_LARGE;
 
     ok = 1;
@@ -123,39 +125,40 @@ int DH_check(const DH *dh, int *ret)
     if (t2 == NULL)
         goto err;
 
-    if (dh->q) {
-        if (BN_cmp(dh->g, BN_value_one()) <= 0)
+    if (dh->params.q != NULL) {
+        if (BN_cmp(dh->params.g, BN_value_one()) <= 0)
             *ret |= DH_NOT_SUITABLE_GENERATOR;
-        else if (BN_cmp(dh->g, dh->p) >= 0)
+        else if (BN_cmp(dh->params.g, dh->params.p) >= 0)
             *ret |= DH_NOT_SUITABLE_GENERATOR;
         else {
             /* Check g^q == 1 mod p */
-            if (!BN_mod_exp(t1, dh->g, dh->q, dh->p, ctx))
+            if (!BN_mod_exp(t1, dh->params.g, dh->params.q, dh->params.p, ctx))
                 goto err;
             if (!BN_is_one(t1))
                 *ret |= DH_NOT_SUITABLE_GENERATOR;
         }
-        r = BN_check_prime(dh->q, ctx, NULL);
+        r = BN_check_prime(dh->params.q, ctx, NULL);
         if (r < 0)
             goto err;
         if (!r)
             *ret |= DH_CHECK_Q_NOT_PRIME;
         /* Check p == 1 mod q  i.e. q divides p - 1 */
-        if (!BN_div(t1, t2, dh->p, dh->q, ctx))
+        if (!BN_div(t1, t2, dh->params.p, dh->params.q, ctx))
             goto err;
         if (!BN_is_one(t2))
             *ret |= DH_CHECK_INVALID_Q_VALUE;
-        if (dh->j && BN_cmp(dh->j, t1))
+        if (dh->params.j != NULL
+            && BN_cmp(dh->params.j, t1))
             *ret |= DH_CHECK_INVALID_J_VALUE;
     }
 
-    r = BN_check_prime(dh->p, ctx, NULL);
+    r = BN_check_prime(dh->params.p, ctx, NULL);
     if (r < 0)
         goto err;
     if (!r)
         *ret |= DH_CHECK_P_NOT_PRIME;
-    else if (!dh->q) {
-        if (!BN_rshift1(t1, dh->p))
+    else if (dh->params.q == NULL) {
+        if (!BN_rshift1(t1, dh->params.p))
             goto err;
         r = BN_check_prime(t1, ctx, NULL);
         if (r < 0)
@@ -203,14 +206,14 @@ int DH_check_pub_key(const DH *dh, const BIGNUM *pub_key, int *ret)
         goto err;
     if (BN_cmp(pub_key, tmp) <= 0)
         *ret |= DH_CHECK_PUBKEY_TOO_SMALL;
-    if (BN_copy(tmp, dh->p) == NULL || !BN_sub_word(tmp, 1))
+    if (BN_copy(tmp, dh->params.p) == NULL || !BN_sub_word(tmp, 1))
         goto err;
     if (BN_cmp(pub_key, tmp) >= 0)
         *ret |= DH_CHECK_PUBKEY_TOO_LARGE;
 
-    if (dh->q != NULL) {
+    if (dh->params.q != NULL) {
         /* Check pub_key^q == 1 mod p */
-        if (!BN_mod_exp(tmp, pub_key, dh->q, dh->p, ctx))
+        if (!BN_mod_exp(tmp, pub_key, dh->params.q, dh->params.p, ctx))
             goto err;
         if (!BN_is_one(tmp))
             *ret |= DH_CHECK_PUBKEY_INVALID;
diff --git a/crypto/dh/dh_gen.c b/crypto/dh/dh_gen.c
index 0506bbe2e5..75548592b8 100644
--- a/crypto/dh/dh_gen.c
+++ b/crypto/dh/dh_gen.c
@@ -81,9 +81,9 @@ static int dh_builtin_genparams(DH *ret, int prime_len, int generator,
         goto err;
 
     /* Make sure 'ret' has the necessary elements */
-    if (!ret->p && ((ret->p = BN_new()) == NULL))
+    if (ret->params.p == NULL && ((ret->params.p = BN_new()) == NULL))
         goto err;
-    if (!ret->g && ((ret->g = BN_new()) == NULL))
+    if (ret->params.g == NULL && ((ret->params.g = BN_new()) == NULL))
         goto err;
 
     if (generator <= 1) {
@@ -115,11 +115,11 @@ static int dh_builtin_genparams(DH *ret, int prime_len, int generator,
         g = generator;
     }
 
-    if (!BN_generate_prime_ex(ret->p, prime_len, 1, t1, t2, cb))
+    if (!BN_generate_prime_ex(ret->params.p, prime_len, 1, t1, t2, cb))
         goto err;
     if (!BN_GENCB_call(cb, 3, 0))
         goto err;
-    if (!BN_set_word(ret->g, g))
+    if (!BN_set_word(ret->params.g, g))
         goto err;
     ret->dirty_cnt++;
     ok = 1;
diff --git a/crypto/dh/dh_key.c b/crypto/dh/dh_key.c
index bd9b5c824b..4c5d78a19f 100644
--- a/crypto/dh/dh_key.c
+++ b/crypto/dh/dh_key.c
@@ -34,12 +34,12 @@ int dh_compute_key(OPENSSL_CTX *libctx, unsigned char *key,
     int check_result;
 #endif
 
-    if (BN_num_bits(dh->p) > OPENSSL_DH_MAX_MODULUS_BITS) {
+    if (BN_num_bits(dh->params.p) > OPENSSL_DH_MAX_MODULUS_BITS) {
         DHerr(0, DH_R_MODULUS_TOO_LARGE);
         goto err;
     }
 
-    if (BN_num_bits(dh->p) < DH_MIN_MODULUS_BITS) {
+    if (BN_num_bits(dh->params.p) < DH_MIN_MODULUS_BITS) {
         DHerr(0, DH_R_MODULUS_TOO_SMALL);
         return 0;
     }
@@ -59,7 +59,7 @@ int dh_compute_key(OPENSSL_CTX *libctx, unsigned char *key,
 
     if (dh->flags & DH_FLAG_CACHE_MONT_P) {
         mont = BN_MONT_CTX_set_locked(&dh->method_mont_p,
-                                      dh->lock, dh->p, ctx);
+                                      dh->lock, dh->params.p, ctx);
         BN_set_flags(dh->priv_key, BN_FLG_CONSTTIME);
         if (!mont)
             goto err;
@@ -71,7 +71,7 @@ int dh_compute_key(OPENSSL_CTX *libctx, unsigned char *key,
         goto err;
     }
 #endif
-    if (!dh->meth->bn_mod_exp(dh, tmp, pub_key, dh->priv_key, dh->p, ctx,
+    if (!dh->meth->bn_mod_exp(dh, tmp, pub_key, dh->priv_key, dh->params.p, ctx,
                               mont)) {
         DHerr(0, ERR_R_BN_LIB);
         goto err;
@@ -101,7 +101,7 @@ int dh_compute_key_padded(OPENSSL_CTX *libctx, unsigned char *key,
 #endif
     if (rv <= 0)
         return rv;
-    pad = BN_num_bytes(dh->p) - rv;
+    pad = BN_num_bytes(dh->params.p) - rv;
     if (pad > 0) {
         memmove(key + pad, key, rv);
         memset(key, 0, pad);
@@ -159,6 +159,7 @@ static int dh_bn_mod_exp(const DH *dh, BIGNUM *r,
 static int dh_init(DH *dh)
 {
     dh->flags |= DH_FLAG_CACHE_MONT_P;
+    ffc_params_init(&dh->params);
     return 1;
 }
 
@@ -189,12 +190,12 @@ static int generate_key(DH *dh)
     BN_MONT_CTX *mont = NULL;
     BIGNUM *pub_key = NULL, *priv_key = NULL;
 
-    if (BN_num_bits(dh->p) > OPENSSL_DH_MAX_MODULUS_BITS) {
+    if (BN_num_bits(dh->params.p) > OPENSSL_DH_MAX_MODULUS_BITS) {
         DHerr(DH_F_GENERATE_KEY, DH_R_MODULUS_TOO_LARGE);
         return 0;
     }
 
-    if (BN_num_bits(dh->p) < DH_MIN_MODULUS_BITS) {
+    if (BN_num_bits(dh->params.p) < DH_MIN_MODULUS_BITS) {
         DHerr(DH_F_GENERATE_KEY, DH_R_MODULUS_TOO_SMALL);
         return 0;
     }
@@ -220,28 +221,29 @@ static int generate_key(DH *dh)
 
     if (dh->flags & DH_FLAG_CACHE_MONT_P) {
         mont = BN_MONT_CTX_set_locked(&dh->method_mont_p,
-                                      dh->lock, dh->p, ctx);
+                                      dh->lock, dh->params.p, ctx);
         if (!mont)
             goto err;
     }
 
     if (generate_new_key) {
-        if (dh->q) {
+        if (dh->params.q != NULL) {
             do {
-                if (!BN_priv_rand_range(priv_key, dh->q))
+                if (!BN_priv_rand_range(priv_key, dh->params.q))
                     goto err;
             }
             while (BN_is_zero(priv_key) || BN_is_one(priv_key));
         } else {
             /* secret exponent length */
-            l = dh->length ? dh->length : BN_num_bits(dh->p) - 1;
+            l = dh->length ? dh->length : BN_num_bits(dh->params.p) - 1;
             if (!BN_priv_rand(priv_key, l, BN_RAND_TOP_ONE, BN_RAND_BOTTOM_ANY))
                 goto err;
             /*
              * We handle just one known case where g is a quadratic non-residue:
              * for g = 2: p % 8 == 3
              */
-            if (BN_is_word(dh->g, DH_GENERATOR_2) && !BN_is_bit_set(dh->p, 2)) {
+            if (BN_is_word(dh->params.g, DH_GENERATOR_2)
+                && !BN_is_bit_set(dh->params.p, 2)) {
                 /* clear bit 0, since it won't be a secret anyway */
                 if (!BN_clear_bit(priv_key, 0))
                     goto err;
@@ -256,7 +258,8 @@ static int generate_key(DH *dh)
             goto err;
         BN_with_flags(prk, priv_key, BN_FLG_CONSTTIME);
 
-        if (!dh->meth->bn_mod_exp(dh, pub_key, dh->g, prk, dh->p, ctx, mont)) {
+        if (!dh->meth->bn_mod_exp(dh, pub_key, dh->params.g, prk, dh->params.p,
+                                  ctx, mont)) {
             BN_clear_free(prk);
             goto err;
         }
@@ -280,6 +283,7 @@ static int generate_key(DH *dh)
     return ok;
 }
 
+
 int dh_buf2key(DH *dh, const unsigned char *buf, size_t len)
 {
     int err_reason = DH_R_BN_ERROR;
diff --git a/crypto/dh/dh_lib.c b/crypto/dh/dh_lib.c
index c9679d7e52..2f5aa10401 100644
--- a/crypto/dh/dh_lib.c
+++ b/crypto/dh/dh_lib.c
@@ -14,6 +14,7 @@
 #include "dh_local.h"
 #include "crypto/dh.h"
 #include <openssl/engine.h>
+#include "crypto/dh.h"
 
 #ifndef FIPS_MODE
 int DH_set_method(DH *dh, const DH_METHOD *meth)
@@ -122,12 +123,7 @@ void DH_free(DH *r)
 
     CRYPTO_THREAD_lock_free(r->lock);
 
-    BN_clear_free(r->p);
-    BN_clear_free(r->g);
-    BN_clear_free(r->q);
-    BN_clear_free(r->j);
-    OPENSSL_free(r->seed);
-    BN_clear_free(r->counter);
+    ffc_params_cleanup(&r->params);
     BN_clear_free(r->pub_key);
     BN_clear_free(r->priv_key);
     OPENSSL_free(r);
@@ -159,35 +155,30 @@ void *DH_get_ex_data(DH *d, int idx)
 
 int DH_bits(const DH *dh)
 {
-    return BN_num_bits(dh->p);
+    return BN_num_bits(dh->params.p);
 }
 
 int DH_size(const DH *dh)
 {
-    return BN_num_bytes(dh->p);
+    return BN_num_bytes(dh->params.p);
 }
 
 int DH_security_bits(const DH *dh)
 {
     int N;
-    if (dh->q)
-        N = BN_num_bits(dh->q);
+    if (dh->params.q != NULL)
+        N = BN_num_bits(dh->params.q);
     else if (dh->length)
         N = dh->length;
     else
         N = -1;
-    return BN_security_bits(BN_num_bits(dh->p), N);
+    return BN_security_bits(BN_num_bits(dh->params.p), N);
 }
 
 void DH_get0_pqg(const DH *dh,
                  const BIGNUM **p, const BIGNUM **q, const BIGNUM **g)
 {
-    if (p != NULL)
-        *p = dh->p;
-    if (q != NULL)
-        *q = dh->q;
-    if (g != NULL)
-        *g = dh->g;
+    ffc_params_get0_pqg(&dh->params, p, q, g);
 }
 
 int DH_set0_pqg(DH *dh, BIGNUM *p, BIGNUM *q, BIGNUM *g)
@@ -195,26 +186,14 @@ int DH_set0_pqg(DH *dh, BIGNUM *p, BIGNUM *q, BIGNUM *g)
     /* If the fields p and g in d are NULL, the corresponding input
      * parameters MUST be non-NULL.  q may remain NULL.
      */
-    if ((dh->p == NULL && p == NULL)
-        || (dh->g == NULL && g == NULL))
+    if ((dh->params.p == NULL && p == NULL)
+        || (dh->params.g == NULL && g == NULL))
         return 0;
 
-    if (p != NULL) {
-        BN_free(dh->p);
-        dh->p = p;
-    }
-    if (q != NULL) {
-        BN_free(dh->q);
-        dh->q = q;
-    }
-    if (g != NULL) {
-        BN_free(dh->g);
-        dh->g = g;
-    }
+    ffc_params_set0_pqg(&dh->params, p, q, g);
 
-    if (q != NULL) {
+    if (q != NULL)
         dh->length = BN_num_bits(q);
-    }
 
     dh->dirty_cnt++;
     return 1;
@@ -256,17 +235,17 @@ int DH_set0_key(DH *dh, BIGNUM *pub_key, BIGNUM *priv_key)
 
 const BIGNUM *DH_get0_p(const DH *dh)
 {
-    return dh->p;
+    return dh->params.p;
 }
 
 const BIGNUM *DH_get0_q(const DH *dh)
 {
-    return dh->q;
+    return dh->params.q;
 }
 
 const BIGNUM *DH_get0_g(const DH *dh)
 {
-    return dh->g;
+    return dh->params.g;
 }
 
 const BIGNUM *DH_get0_priv_key(const DH *dh)
@@ -300,3 +279,8 @@ ENGINE *DH_get0_engine(DH *dh)
     return dh->engine;
 }
 #endif /*FIPS_MODE */
+
+FFC_PARAMS *dh_get0_params(DH *dh)
+{
+    return &dh->params;
+}
diff --git a/crypto/dh/dh_local.h b/crypto/dh/dh_local.h
index 2a200c748e..57d9d3489f 100644
--- a/crypto/dh/dh_local.h
+++ b/crypto/dh/dh_local.h
@@ -1,5 +1,5 @@
 /*
- * Copyright 2016 The OpenSSL Project Authors. All Rights Reserved.
+ * Copyright 2016-2020 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
@@ -9,6 +9,7 @@
 
 #include <openssl/dh.h>
 #include "internal/refcount.h"
+#include "internal/ffc.h"
 
 #define DH_MIN_MODULUS_BITS     512
 
@@ -19,19 +20,12 @@ struct dh_st {
      */
     int pad;
     int version;
-    BIGNUM *p;
-    BIGNUM *g;
-    int32_t length;             /* optional */
+    FFC_PARAMS params;
+    int32_t length;             /* optional value of N (if there is no q) */
     BIGNUM *pub_key;            /* g^x % p */
     BIGNUM *priv_key;           /* x */
     int flags;
     BN_MONT_CTX *method_mont_p;
-    /* Place holders if we want to do X9.42 DH */
-    BIGNUM *q;
-    BIGNUM *j;
-    unsigned char *seed;
-    int seedlen;
-    BIGNUM *counter;
     CRYPTO_REF_COUNT references;
 #ifndef FIPS_MODE
     CRYPTO_EX_DATA ex_data;
diff --git a/crypto/dh/dh_rfc5114.c b/crypto/dh/dh_rfc5114.c
index 823f6d92e3..3bbfea12d3 100644
--- a/crypto/dh/dh_rfc5114.c
+++ b/crypto/dh/dh_rfc5114.c
@@ -26,10 +26,10 @@ DH *DH_get_##x(void) \
 \
     if (dh == NULL) \
         return NULL; \
-    dh->p = BN_dup(&_bignum_dh##x##_p); \
-    dh->g = BN_dup(&_bignum_dh##x##_g); \
-    dh->q = BN_dup(&_bignum_dh##x##_q); \
-    if (dh->p == NULL || dh->q == NULL || dh->g == NULL) {\
+    dh->params.p = BN_dup(&_bignum_dh##x##_p); \
+    dh->params.g = BN_dup(&_bignum_dh##x##_g); \
+    dh->params.q = BN_dup(&_bignum_dh##x##_q); \
+    if (dh->params.p == NULL || dh->params.q == NULL || dh->params.g == NULL) {\
         DH_free(dh); \
         return NULL; \
     } \
diff --git a/crypto/dh/dh_rfc7919.c b/crypto/dh/dh_rfc7919.c
index e36712facf..92e5000e28 100644
--- a/crypto/dh/dh_rfc7919.c
+++ b/crypto/dh/dh_rfc7919.c
@@ -19,8 +19,8 @@ static DH *dh_param_init(const BIGNUM *p, int32_t nbits)
     DH *dh = DH_new();
     if (dh == NULL)
         return NULL;
-    dh->p = (BIGNUM *)p;
-    dh->g = (BIGNUM *)&_bignum_const_2;
+    dh->params.p = (BIGNUM *)p;
+    dh->params.g = (BIGNUM *)&_bignum_const_2;
     dh->length = nbits;
     dh->dirty_cnt++;
     return dh;
@@ -49,25 +49,25 @@ int DH_get_nid(const DH *dh)
 {
     int nid;
 
-    if (BN_get_word(dh->g) != 2)
+    if (BN_get_word(dh->params.g) != 2)
         return NID_undef;
-    if (!BN_cmp(dh->p, &_bignum_ffdhe2048_p))
+    if (!BN_cmp(dh->params.p, &_bignum_ffdhe2048_p))
         nid = NID_ffdhe2048;
-    else if (!BN_cmp(dh->p, &_bignum_ffdhe3072_p))
+    else if (!BN_cmp(dh->params.p, &_bignum_ffdhe3072_p))
         nid = NID_ffdhe3072;
-    else if (!BN_cmp(dh->p, &_bignum_ffdhe4096_p))
+    else if (!BN_cmp(dh->params.p, &_bignum_ffdhe4096_p))
         nid = NID_ffdhe4096;
-    else if (!BN_cmp(dh->p, &_bignum_ffdhe6144_p))
+    else if (!BN_cmp(dh->params.p, &_bignum_ffdhe6144_p))
         nid = NID_ffdhe6144;
-    else if (!BN_cmp(dh->p, &_bignum_ffdhe8192_p))
+    else if (!BN_cmp(dh->params.p, &_bignum_ffdhe8192_p))
         nid = NID_ffdhe8192;
     else
         return NID_undef;
-    if (dh->q != NULL) {
-        BIGNUM *q = BN_dup(dh->p);
+    if (dh->params.q != NULL) {
+        BIGNUM *q = BN_dup(dh->params.p);
 
         /* Check q = p * 2 + 1 we already know q is odd, so just shift right */
-        if (q == NULL || !BN_rshift1(q, q) || !BN_cmp(dh->q, q))
+        if (q == NULL || !BN_rshift1(q, q) || !BN_cmp(dh->params.q, q))
             nid = NID_undef;
         BN_free(q);
     }
diff --git a/crypto/dsa/dsa_ameth.c b/crypto/dsa/dsa_ameth.c
index ddd262bdde..510b204b2d 100644
--- a/crypto/dsa/dsa_ameth.c
+++ b/crypto/dsa/dsa_ameth.c
@@ -88,7 +88,10 @@ static int dsa_pub_encode(X509_PUBKEY *pk, const EVP_PKEY *pkey)
     ASN1_OBJECT *aobj;
 
     dsa = pkey->pkey.dsa;
-    if (pkey->save_parameters && dsa->p && dsa->q && dsa->g) {
+    if (pkey->save_parameters
+        && dsa->params.p != NULL
+        && dsa->params.q != NULL
+        && dsa->params.g != NULL) {
         str = ASN1_STRING_new();
         if (str == NULL) {
             DSAerr(DSA_F_DSA_PUB_ENCODE, ERR_R_MALLOC_FAILURE);
@@ -183,7 +186,8 @@ static int dsa_priv_decode(EVP_PKEY *pkey, const PKCS8_PRIV_KEY_INFO *p8)
     }
 
     BN_set_flags(dsa->priv_key, BN_FLG_CONSTTIME);
-    if (!BN_mod_exp(dsa->pub_key, dsa->g, dsa->priv_key, dsa->p, ctx)) {
+    if (!BN_mod_exp(dsa->pub_key, dsa->params.g, dsa->priv_key, dsa->params.p,
+                    ctx)) {
         DSAerr(DSA_F_DSA_PRIV_DECODE, DSA_R_BN_ERROR);
         goto dsaerr;
     }
@@ -275,55 +279,34 @@ static int dsa_missing_parameters(const EVP_PKEY *pkey)
 {
     DSA *dsa;
     dsa = pkey->pkey.dsa;
-    if (dsa == NULL || dsa->p == NULL || dsa->q == NULL || dsa->g == NULL)
-        return 1;
-    return 0;
+    return dsa == NULL
+        || dsa->params.p == NULL
+        || dsa->params.q == NULL
+        || dsa->params.g == NULL;
 }
 
 static int dsa_copy_parameters(EVP_PKEY *to, const EVP_PKEY *from)
 {
-    BIGNUM *a;
-
     if (to->pkey.dsa == NULL) {
         to->pkey.dsa = DSA_new();
         if (to->pkey.dsa == NULL)
             return 0;