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)

8 files changed, 130 insertions, 170 deletions

diff --git a/crypto/dsa/dsa_ameth.c b/crypto/dsa/dsa_ameth.c
index ddd262b..510b204 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;
     }
-
-    if ((a = BN_dup(from->pkey.dsa->p)) == NULL)
+    if (!ffc_params_copy(&to->pkey.dsa->params, &from->pkey.dsa->params))
         return 0;
-    BN_free(to->pkey.dsa->p);
-    to->pkey.dsa->p = a;
 
-    if ((a = BN_dup(from->pkey.dsa->q)) == NULL)
-        return 0;
-    BN_free(to->pkey.dsa->q);
-    to->pkey.dsa->q = a;
-
-    if ((a = BN_dup(from->pkey.dsa->g)) == NULL)
-        return 0;
-    BN_free(to->pkey.dsa->g);
-    to->pkey.dsa->g = a;
     to->pkey.dsa->dirty_cnt++;
     return 1;
 }
 
 static int dsa_cmp_parameters(const EVP_PKEY *a, const EVP_PKEY *b)
 {
-    if (BN_cmp(a->pkey.dsa->p, b->pkey.dsa->p) ||
-        BN_cmp(a->pkey.dsa->q, b->pkey.dsa->q) ||
-        BN_cmp(a->pkey.dsa->g, b->pkey.dsa->g))
-        return 0;
-    else
-        return 1;
+    return ffc_params_cmp(&a->pkey.dsa->params, &b->pkey.dsa->params, 1);
 }
 
 static int dsa_pub_cmp(const EVP_PKEY *a, const EVP_PKEY *b)
 {
-    if (BN_cmp(b->pkey.dsa->pub_key, a->pkey.dsa->pub_key) != 0)
-        return 0;
-    else
-        return 1;
+    return BN_cmp(b->pkey.dsa->pub_key, a->pkey.dsa->pub_key) == 0;
 }
 
 static void int_dsa_free(EVP_PKEY *pkey)
@@ -338,8 +321,8 @@ static int do_dsa_print(BIO *bp, const DSA *x, int off, int ptype)
     const BIGNUM *priv_key, *pub_key;
     int mod_len = 0;
 
-    if (x->p != NULL)
-        mod_len = BN_num_bits(x->p);
+    if (x->params.p != NULL)
+        mod_len = DSA_bits(x);
 
     if (ptype == 2)
         priv_key = x->priv_key;
@@ -358,11 +341,10 @@ static int do_dsa_print(BIO *bp, const DSA *x, int off, int ptype)
     else
         ktype = "DSA-Parameters";
 
-    if (priv_key) {
+    if (priv_key != NULL) {
         if (!BIO_indent(bp, off, 128))
             goto err;
-        if (BIO_printf(bp, "%s: (%d bit)\n", ktype, BN_num_bits(x->p))
-            <= 0)
+        if (BIO_printf(bp, "%s: (%d bit)\n", ktype, mod_len) <= 0)
             goto err;
     } else {
         if (BIO_printf(bp, "Public-Key: (%d bit)\n", mod_len) <= 0)
@@ -373,11 +355,7 @@ static int do_dsa_print(BIO *bp, const DSA *x, int off, int ptype)
         goto err;
     if (!ASN1_bn_print(bp, "pub: ", pub_key, NULL, off))
         goto err;
-    if (!ASN1_bn_print(bp, "P:   ", x->p, NULL, off))
-        goto err;
-    if (!ASN1_bn_print(bp, "Q:   ", x->q, NULL, off))
-        goto err;
-    if (!ASN1_bn_print(bp, "G:   ", x->g, NULL, off))
+    if (!ffc_params_print(bp, &x->params, off))
         goto err;
     ret = 1;
  err:
@@ -446,7 +424,7 @@ static int dsa_sig_print(BIO *bp, const X509_ALGOR *sigalg,
     DSA_SIG *dsa_sig;
     const unsigned char *p;
 
-    if (!sig) {
+    if (sig == NULL) {
         if (BIO_puts(bp, "\n") <= 0)
             return 0;
         else
@@ -454,7 +432,7 @@ static int dsa_sig_print(BIO *bp, const X509_ALGOR *sigalg,
     }
     p = sig->data;
     dsa_sig = d2i_DSA_SIG(NULL, &p, sig->length);
-    if (dsa_sig) {
+    if (dsa_sig != NULL) {
         int rv = 0;
         const BIGNUM *r, *s;
 
diff --git a/crypto/dsa/dsa_asn1.c b/crypto/dsa/dsa_asn1.c
index 20bf251..ba1cbad 100644
--- a/crypto/dsa/dsa_asn1.c
+++ b/crypto/dsa/dsa_asn1.c
@@ -34,9 +34,9 @@ static int dsa_cb(int operation, ASN1_VALUE **pval, const ASN1_ITEM *it,
 
 ASN1_SEQUENCE_cb(DSAPrivateKey, dsa_cb) = {
         ASN1_EMBED(DSA, version, INT32),
-        ASN1_SIMPLE(DSA, p, BIGNUM),
-        ASN1_SIMPLE(DSA, q, BIGNUM),
-        ASN1_SIMPLE(DSA, g, BIGNUM),
+        ASN1_SIMPLE(DSA, params.p, BIGNUM),
+        ASN1_SIMPLE(DSA, params.q, BIGNUM),
+        ASN1_SIMPLE(DSA, params.g, BIGNUM),
         ASN1_SIMPLE(DSA, pub_key, BIGNUM),
         ASN1_SIMPLE(DSA, priv_key, CBIGNUM)
 } static_ASN1_SEQUENCE_END_cb(DSA, DSAPrivateKey)
@@ -44,18 +44,18 @@ ASN1_SEQUENCE_cb(DSAPrivateKey, dsa_cb) = {
 IMPLEMENT_ASN1_ENCODE_FUNCTIONS_fname(DSA, DSAPrivateKey, DSAPrivateKey)
 
 ASN1_SEQUENCE_cb(DSAparams, dsa_cb) = {
-        ASN1_SIMPLE(DSA, p, BIGNUM),
-        ASN1_SIMPLE(DSA, q, BIGNUM),
-        ASN1_SIMPLE(DSA, g, BIGNUM),
+        ASN1_SIMPLE(DSA, params.p, BIGNUM),
+        ASN1_SIMPLE(DSA, params.q, BIGNUM),
+        ASN1_SIMPLE(DSA, params.g, BIGNUM),
 } static_ASN1_SEQUENCE_END_cb(DSA, DSAparams)
 
 IMPLEMENT_ASN1_ENCODE_FUNCTIONS_fname(DSA, DSAparams, DSAparams)
 
 ASN1_SEQUENCE_cb(DSAPublicKey, dsa_cb) = {
         ASN1_SIMPLE(DSA, pub_key, BIGNUM),
-        ASN1_SIMPLE(DSA, p, BIGNUM),
-        ASN1_SIMPLE(DSA, q, BIGNUM),
-        ASN1_SIMPLE(DSA, g, BIGNUM)
+        ASN1_SIMPLE(DSA, params.p, BIGNUM),
+        ASN1_SIMPLE(DSA, params.q, BIGNUM),
+        ASN1_SIMPLE(DSA, params.g, BIGNUM)
 } static_ASN1_SEQUENCE_END_cb(DSA, DSAPublicKey)
 
 IMPLEMENT_ASN1_ENCODE_FUNCTIONS_fname(DSA, DSAPublicKey, DSAPublicKey)
diff --git a/crypto/dsa/dsa_gen.c b/crypto/dsa/dsa_gen.c
index 67551e5..02c2bd8 100644
--- a/crypto/dsa/dsa_gen.c
+++ b/crypto/dsa/dsa_gen.c
@@ -274,14 +274,16 @@ int dsa_builtin_paramgen(DSA *ret, size_t bits, size_t qbits,
     ok = 1;
  err:
     if (ok) {
-        BN_free(ret->p);
-        BN_free(ret->q);
-        BN_free(ret->g);
-        ret->p = BN_dup(p);
-        ret->q = BN_dup(q);
-        ret->g = BN_dup(g);
+        BN_free(ret->params.p);
+        BN_free(ret->params.q);
+        BN_free(ret->params.g);
+        ret->params.p = BN_dup(p);
+        ret->params.q = BN_dup(q);
+        ret->params.g = BN_dup(g);
         ret->dirty_cnt++;
-        if (ret->p == NULL || ret->q == NULL || ret->g == NULL) {
+        if (ret->params.p == NULL
+            || ret->params.q == NULL
+            || ret->params.g == NULL) {
             ok = 0;
             goto err;
         }
@@ -343,7 +345,7 @@ int dsa_builtin_paramgen2(DSA *ret, size_t L, size_t N,
 
     mdsize = EVP_MD_size(evpmd);
     /* If unverifiable g generation only don't need seed */
-    if (!ret->p || !ret->q || idx >= 0) {
+    if (!ret->params.p || !ret->params.q || idx >= 0) {
         if (seed_len == 0)
             seed_len = mdsize;
 
@@ -379,9 +381,9 @@ int dsa_builtin_paramgen2(DSA *ret, size_t L, size_t N,
         goto err;
 
     /* if p, q already supplied generate g only */
-    if (ret->p && ret->q) {
-        p = ret->p;
-        q = ret->q;
+    if (ret->params.p && ret->params.q) {
+        p = ret->params.p;
+        q = ret->params.q;
         if (idx >= 0)
             memcpy(seed_tmp, seed, seed_len);
         goto g_only;
@@ -583,17 +585,19 @@ int dsa_builtin_paramgen2(DSA *ret, size_t L, size_t N,
     ok = 1;
  err:
     if (ok == 1) {
-        if (p != ret->p) {
-            BN_free(ret->p);
-            ret->p = BN_dup(p);
+        if (p != ret->params.p) {
+            BN_free(ret->params.p);
+            ret->params.p = BN_dup(p);
         }
-        if (q != ret->q) {
-            BN_free(ret->q);
-            ret->q = BN_dup(q);
+        if (q != ret->params.q) {
+            BN_free(ret->params.q);
+            ret->params.q = BN_dup(q);
         }
-        BN_free(ret->g);
-        ret->g = BN_dup(g);
-        if (ret->p == NULL || ret->q == NULL || ret->g == NULL) {
+        BN_free(ret->params.g);
+        ret->params.g = BN_dup(g);
+        if (ret->params.p == NULL
+            || ret->params.q == NULL
+            || ret->params.g == NULL) {
             ok = -1;
             goto err;
         }
diff --git a/crypto/dsa/dsa_key.c b/crypto/dsa/dsa_key.c
index 6e5039a..efc1252 100644
--- a/crypto/dsa/dsa_key.c
+++ b/crypto/dsa/dsa_key.c
@@ -38,7 +38,7 @@ static int dsa_builtin_keygen(DSA *dsa)
         priv_key = dsa->priv_key;
 
     do
-        if (!BN_priv_rand_range(priv_key, dsa->q))
+        if (!BN_priv_rand_range(priv_key, dsa->params.q))
             goto err;
     while (BN_is_zero(priv_key)) ;
 
@@ -55,7 +55,7 @@ static int dsa_builtin_keygen(DSA *dsa)
             goto err;
         BN_with_flags(prk, priv_key, BN_FLG_CONSTTIME);
 
-        if (!BN_mod_exp(pub_key, dsa->g, prk, dsa->p, ctx)) {
+        if (!BN_mod_exp(pub_key, dsa->params.g, prk, dsa->params.p, ctx)) {
             BN_free(prk);
             goto err;
         }
diff --git a/crypto/dsa/dsa_lib.c b/crypto/dsa/dsa_lib.c
index 976eb62..469746e 100644
--- a/crypto/dsa/dsa_lib.c
+++ b/crypto/dsa/dsa_lib.c
@@ -1,5 +1,5 @@
 /*
- * Copyright 1995-2018 The OpenSSL Project Authors. All Rights Reserved.
+ * Copyright 1995-2020 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
@@ -11,11 +11,11 @@
 #include "internal/cryptlib.h"
 #include "internal/refcount.h"
 #include <openssl/bn.h>
-#include "dsa_local.h"
 #include <openssl/asn1.h>
 #include <openssl/engine.h>
-#include <openssl/dh.h>
+#include "dsa_local.h"
 #include "crypto/dsa.h"
+#include "crypto/dh.h" /* required by DSA_dup_DH() */
 
 #ifndef FIPS_MODE
 
@@ -29,34 +29,25 @@ void *DSA_get_ex_data(DSA *d, int idx)
     return CRYPTO_get_ex_data(&d->ex_data, idx);
 }
 
-#ifndef OPENSSL_NO_DH
+# ifndef OPENSSL_NO_DH
 DH *DSA_dup_DH(const DSA *r)
 {
     /*
-     * DSA has p, q, g, optional pub_key, optional priv_key. DH has p,
-     * optional length, g, optional pub_key, optional priv_key, optional q.
+     * DSA has p, q, g, optional pub_key, optional priv_key.
+     * DH has p, optional length, g, optional pub_key,
+     * optional priv_key, optional q.
      */
-
     DH *ret = NULL;
-    BIGNUM *p = NULL, *q = NULL, *g = NULL, *pub_key = NULL, *priv_key = NULL;
+    BIGNUM *pub_key = NULL, *priv_key = NULL;
 
     if (r == NULL)
         goto err;
     ret = DH_new();
     if (ret == NULL)
         goto err;
-    if (r->p != NULL || r->g != NULL || r->q != NULL) {
-        if (r->p == NULL || r->g == NULL || r->q == NULL) {
-            /* Shouldn't happen */
-            goto err;
-        }
-        p = BN_dup(r->p);
-        g = BN_dup(r->g);
-        q = BN_dup(r->q);
-        if (p == NULL || g == NULL || q == NULL || !DH_set0_pqg(ret, p, q, g))
-            goto err;
-        p = g = q = NULL;
-    }
+
+    if (!ffc_params_copy(dh_get0_params(ret), &r->params))
+        goto err;
 
     if (r->pub_key != NULL) {
         pub_key = BN_dup(r->pub_key);
@@ -77,29 +68,26 @@ DH *DSA_dup_DH(const DSA *r)
     return ret;
 
  err:
-    BN_free(p);
-    BN_free(g);
-    BN_free(q);
     BN_free(pub_key);
     BN_free(priv_key);
     DH_free(ret);
     return NULL;
 }
-#endif
+# endif /*  OPENSSL_NO_DH */
 
 const BIGNUM *DSA_get0_p(const DSA *d)
 {
-    return d->p;
+    return d->params.p;
 }
 
 const BIGNUM *DSA_get0_q(const DSA *d)
 {
-    return d->q;
+    return d->params.q;
 }
 
 const BIGNUM *DSA_get0_g(const DSA *d)
 {
-    return d->g;
+    return d->params.g;
 }
 
 const BIGNUM *DSA_get0_pub_key(const DSA *d)
@@ -250,9 +238,7 @@ void DSA_free(DSA *r)
 
     CRYPTO_THREAD_lock_free(r->lock);
 
-    BN_clear_free(r->p);
-    BN_clear_free(r->q);
-    BN_clear_free(r->g);
+    ffc_params_cleanup(&r->params);
     BN_clear_free(r->pub_key);
     BN_clear_free(r->priv_key);
     OPENSSL_free(r);
@@ -273,12 +259,7 @@ int DSA_up_ref(DSA *r)
 void DSA_get0_pqg(const DSA *d,
                   const BIGNUM **p, const BIGNUM **q, const BIGNUM **g)
 {
-    if (p != NULL)
-        *p = d->p;
-    if (q != NULL)
-        *q = d->q;
-    if (g != NULL)
-        *g = d->g;
+    ffc_params_get0_pqg(&d->params, p, q, g);
 }
 
 int DSA_set0_pqg(DSA *d, BIGNUM *p, BIGNUM *q, BIGNUM *g)
@@ -286,23 +267,12 @@ int DSA_set0_pqg(DSA *d, BIGNUM *p, BIGNUM *q, BIGNUM *g)
     /* If the fields p, q and g in d are NULL, the corresponding input
      * parameters MUST be non-NULL.
      */
-    if ((d->p == NULL && p == NULL)
-        || (d->q == NULL && q == NULL)
-        || (d->g == NULL && g == NULL))
+    if ((d->params.p == NULL && p == NULL)
+        || (d->params.q == NULL && q == NULL)
+        || (d->params.g == NULL && g == NULL))
         return 0;
 
-    if (p != NULL) {
-        BN_free(d->p);
-        d->p = p;
-    }
-    if (q != NULL) {
-        BN_free(d->q);
-        d->q = q;
-    }
-    if (g != NULL) {
-        BN_free(d->g);
-        d->g = g;
-    }
+    ffc_params_set0_pqg(&d->params, p, q, g);
     d->dirty_cnt++;
 
     return 1;
@@ -341,12 +311,13 @@ int DSA_set0_key(DSA *d, BIGNUM *pub_key, BIGNUM *priv_key)
 
 int DSA_security_bits(const DSA *d)
 {
-    if (d->p && d->q)
-        return BN_security_bits(BN_num_bits(d->p), BN_num_bits(d->q));
+    if (d->params.p != NULL && d->params.q != NULL)
+        return BN_security_bits(BN_num_bits(d->params.p),
+                                BN_num_bits(d->params.q));
     return -1;
 }
 
 int DSA_bits(const DSA *dsa)
 {
-    return BN_num_bits(dsa->p);
+    return BN_num_bits(dsa->params.p);
 }
diff --git a/crypto/dsa/dsa_local.h b/crypto/dsa/dsa_local.h
index f0ec734..49b36c5 100644
--- a/crypto/dsa/dsa_local.h
+++ b/crypto/dsa/dsa_local.h
@@ -9,6 +9,7 @@
 
 #include <openssl/dsa.h>
 #include "internal/refcount.h"
+#include "internal/ffc.h"
 
 struct dsa_st {
     /*
@@ -17,9 +18,7 @@ struct dsa_st {
      */
     int pad;
     int32_t version;
-    BIGNUM *p;
-    BIGNUM *q;                  /* == 20 */
-    BIGNUM *g;
+    FFC_PARAMS params;
     BIGNUM *pub_key;            /* y public key */
     BIGNUM *priv_key;           /* x private key */
     int flags;
diff --git a/crypto/dsa/dsa_ossl.c b/crypto/dsa/dsa_ossl.c
index af0fa6b..8de5a36 100644
--- a/crypto/dsa/dsa_ossl.c
+++ b/crypto/dsa/dsa_ossl.c
@@ -71,7 +71,9 @@ DSA_SIG *dsa_do_sign_int(OPENSSL_CTX *libctx, const unsigned char *dgst,
     DSA_SIG *ret = NULL;
     int rv = 0;
 
-    if (dsa->p == NULL || dsa->q == NULL || dsa->g == NULL) {
+    if (dsa->params.p == NULL
+        || dsa->params.q == NULL
+        || dsa->params.g == NULL) {
         reason = DSA_R_MISSING_PARAMETERS;
         goto err;
     }
@@ -102,13 +104,13 @@ DSA_SIG *dsa_do_sign_int(OPENSSL_CTX *libctx, const unsigned char *dgst,
     if (!dsa_sign_setup(dsa, ctx, &kinv, &ret->r, dgst, dlen))
         goto err;
 
-    if (dlen > BN_num_bytes(dsa->q))
+    if (dlen > BN_num_bytes(dsa->params.q))
         /*
          * if the digest length is greater than the size of q use the
          * BN_num_bits(dsa->q) leftmost bits of the digest, see fips 186-3,
          * 4.2
          */
-        dlen = BN_num_bytes(dsa->q);
+        dlen = BN_num_bytes(dsa->params.q);
     if (BN_bin2bn(dgst, dlen, m) == NULL)
         goto err;
 
@@ -124,7 +126,7 @@ DSA_SIG *dsa_do_sign_int(OPENSSL_CTX *libctx, const unsigned char *dgst,
 
     /* Generate a blinding value */
     do {
-        if (!BN_priv_rand_ex(blind, BN_num_bits(dsa->q) - 1,
+        if (!BN_priv_rand_ex(blind, BN_num_bits(dsa->params.q) - 1,
                              BN_RAND_TOP_ANY, BN_RAND_BOTTOM_ANY, ctx))
             goto err;
     } while (BN_is_zero(blind));
@@ -133,27 +135,27 @@ DSA_SIG *dsa_do_sign_int(OPENSSL_CTX *libctx, const unsigned char *dgst,
     BN_set_flags(tmp, BN_FLG_CONSTTIME);
 
     /* tmp := blind * priv_key * r mod q */
-    if (!BN_mod_mul(tmp, blind, dsa->priv_key, dsa->q, ctx))
+    if (!BN_mod_mul(tmp, blind, dsa->priv_key, dsa->params.q, ctx))
         goto err;
-    if (!BN_mod_mul(tmp, tmp, ret->r, dsa->q, ctx))
+    if (!BN_mod_mul(tmp, tmp, ret->r, dsa->params.q, ctx))
         goto err;
 
     /* blindm := blind * m mod q */
-    if (!BN_mod_mul(blindm, blind, m, dsa->q, ctx))
+    if (!BN_mod_mul(blindm, blind, m, dsa->params.q, ctx))
         goto err;
 
     /* s : = (blind * priv_key * r) + (blind * m) mod q */
-    if (!BN_mod_add_quick(ret->s, tmp, blindm, dsa->q))
+    if (!BN_mod_add_quick(ret->s, tmp, blindm, dsa->params.q))
         goto err;
 
     /* s := s * k^-1 mod q */
-    if (!BN_mod_mul(ret->s, ret->s, kinv, dsa->q, ctx))
+    if (!BN_mod_mul(ret->s, ret->s, kinv, dsa->params.q, ctx))
         goto err;
 
     /* s:= s * blind^-1 mod q */
-    if (BN_mod_inverse(blind, blind, dsa->q, ctx) == NULL)
+    if (BN_mod_inverse(blind, blind, dsa->params.q, ctx) == NULL)
         goto err;
-    if (!BN_mod_mul(ret->s, ret->s, blind, dsa->q, ctx))
+    if (!BN_mod_mul(ret->s, ret->s, blind, dsa->params.q, ctx))
         goto err;
 
     /*
@@ -197,13 +199,15 @@ static int dsa_sign_setup(DSA *dsa, BN_CTX *ctx_in,
     int ret = 0;
     int q_bits, q_words;
 
-    if (!dsa->p || !dsa->q || !dsa->g) {
+    if (!dsa->params.p || !dsa->params.q || !dsa->params.g) {
         DSAerr(DSA_F_DSA_SIGN_SETUP, DSA_R_MISSING_PARAMETERS);
         return 0;
     }
 
     /* Reject obviously invalid parameters */
-    if (BN_is_zero(dsa->p) || BN_is_zero(dsa->q) || BN_is_zero(dsa->g)) {
+    if (BN_is_zero(dsa->params.p)
+        || BN_is_zero(dsa->params.q)
+        || BN_is_zero(dsa->params.g)) {
         DSAerr(DSA_F_DSA_SIGN_SETUP, DSA_R_INVALID_PARAMETERS);
         return 0;
     }
@@ -225,8 +229,8 @@ static int dsa_sign_setup(DSA *dsa, BN_CTX *ctx_in,
         ctx = ctx_in;
 
     /* Preallocate space */
-    q_bits = BN_num_bits(dsa->q);
-    q_words = bn_get_top(dsa->q);
+    q_bits = BN_num_bits(dsa->params.q);
+    q_words = bn_get_top(dsa->params.q);
     if (!bn_wexpand(k, q_words + 2)
         || !bn_wexpand(l, q_words + 2))
         goto err;
@@ -238,10 +242,10 @@ static int dsa_sign_setup(DSA *dsa, BN_CTX *ctx_in,
              * We calculate k from SHA512(private_key + H(message) + random).
              * This protects the private key from a weak PRNG.
              */
-            if (!BN_generate_dsa_nonce(k, dsa->q, dsa->priv_key, dgst,
+            if (!BN_generate_dsa_nonce(k, dsa->params.q, dsa->priv_key, dgst,
                                        dlen, ctx))
                 goto err;
-        } else if (!BN_priv_rand_range_ex(k, dsa->q, ctx))
+        } else if (!BN_priv_rand_range_ex(k, dsa->params.q, ctx))
             goto err;
     } while (BN_is_zero(k));
 
@@ -250,7 +254,7 @@ static int dsa_sign_setup(DSA *dsa, BN_CTX *ctx_in,
 
     if (dsa->flags & DSA_FLAG_CACHE_MONT_P) {
         if (!BN_MONT_CTX_set_locked(&dsa->method_mont_p,
-                                    dsa->lock, dsa->p, ctx))
+                                    dsa->lock, dsa->params.p, ctx))
             goto err;
     }
 
@@ -269,26 +273,27 @@ static int dsa_sign_setup(DSA *dsa, BN_CTX *ctx_in,
      *     https://github.com/openssl/openssl/pull/7486#discussion_r228323705
      * The fix is to rework BN so these gymnastics aren't required.
      */
-    if (!BN_add(l, k, dsa->q)
-        || !BN_add(k, l, dsa->q))
+    if (!BN_add(l, k, dsa->params.q)
+        || !BN_add(k, l, dsa->params.q))
         goto err;
 
     BN_consttime_swap(BN_is_bit_set(l, q_bits), k, l, q_words + 2);
 
     if ((dsa)->meth->bn_mod_exp != NULL) {
-            if (!dsa->meth->bn_mod_exp(dsa, r, dsa->g, k, dsa->p, ctx,
-                                       dsa->method_mont_p))
+            if (!dsa->meth->bn_mod_exp(dsa, r, dsa->params.g, k, dsa->params.p,
+                                       ctx, dsa->method_mont_p))
                 goto err;
     } else {
-            if (!BN_mod_exp_mont(r, dsa->g, k, dsa->p, ctx, dsa->method_mont_p))
+            if (!BN_mod_exp_mont(r, dsa->params.g, k, dsa->params.p, ctx,
+                                 dsa->method_mont_p))
                 goto err;
     }
 
-    if (!BN_mod(r, r, dsa->q, ctx))
+    if (!BN_mod(r, r, dsa->params.q, ctx))
         goto err;
 
     /* Compute part of 's = inv(k) (m + xr) mod q' */
-    if ((kinv = dsa_mod_inverse_fermat(k, dsa->q, ctx)) == NULL)
+    if ((kinv = dsa_mod_inverse_fermat(k, dsa->params.q, ctx)) == NULL)
         goto err;
 
     BN_clear_free(*kinvp);
@@ -313,19 +318,21 @@ static int dsa_do_verify(const unsigned char *dgst, int dgst_len,
     BN_MONT_CTX *mont = NULL;
     const BIGNUM *r, *s;
     int ret = -1, i;
-    if (!dsa->p || !dsa->q || !dsa->g) {
+    if (dsa->params.p == NULL
+        || dsa->params.q == NULL
+        || dsa->params.g == NULL) {
         DSAerr(DSA_F_DSA_DO_VERIFY, DSA_R_MISSING_PARAMETERS);
         return -1;
     }
 
-    i = BN_num_bits(dsa->q);
+    i = BN_num_bits(dsa->params.q);
     /* fips 186-3 allows only different sizes for q */
     if (i != 160 && i != 224 && i != 256) {
         DSAerr(DSA_F_DSA_DO_VERIFY, DSA_R_BAD_Q_VALUE);
         return -1;
     }
 
-    if (BN_num_bits(dsa->p) > OPENSSL_DSA_MAX_MODULUS_BITS) {
+    if (BN_num_bits(dsa->params.p) > OPENSSL_DSA_MAX_MODULUS_BITS) {
         DSAerr(DSA_F_DSA_DO_VERIFY, DSA_R_MODULUS_TOO_LARGE);
         return -1;
     }
@@ -339,12 +346,12 @@ static int dsa_do_verify(const unsigned char *dgst, int dgst_len,
     DSA_SIG_get0(sig, &r, &s);
 
     if (BN_is_zero(r) || BN_is_negative(r) ||
-        BN_ucmp(r, dsa->q) >= 0) {
+        BN_ucmp(r, dsa->params.q) >= 0) {
         ret = 0;
         goto err;
     }
     if (BN_is_zero(s) || BN_is_negative(s) ||
-        BN_ucmp(s, dsa->q) >= 0) {
+        BN_ucmp(s, dsa->params.q) >= 0) {
         ret = 0;
         goto err;
     }
@@ -352,7 +359,7 @@ static int dsa_do_verify(const unsigned char *dgst, int dgst_len,
     /*
      * Calculate W = inv(S) mod Q save W in u2
      */
-    if ((BN_mod_inverse(u2, s, dsa->q, ctx)) == NULL)
+    if ((BN_mod_inverse(u2, s, dsa->params.q, ctx)) == NULL)
         goto err;
 
     /* save M in u1 */
@@ -367,32 +374,32 @@ static int dsa_do_verify(const unsigned char *dgst, int dgst_len,
         goto err;
 
     /* u1 = M * w mod q */
-    if (!BN_mod_mul(u1, u1, u2, dsa->q, ctx))
+    if (!BN_mod_mul(u1, u1, u2, dsa->params.q, ctx))
         goto err;
 
     /* u2 = r * w mod q */
-    if (!BN_mod_mul(u2, r, u2, dsa->q, ctx))
+    if (!BN_mod_mul(u2, r, u2, dsa->params.q, ctx))
         goto err;
 
     if (dsa->flags & DSA_FLAG_CACHE_MONT_P) {
         mont = BN_MONT_CTX_set_locked(&dsa->method_mont_p,
-                                      dsa->lock, dsa->p, ctx);
+                                      dsa->lock, dsa->params.p, ctx);
         if (!mont)
             goto err;
     }
 
     if (dsa->meth->dsa_mod_exp != NULL) {
-        if (!dsa->meth->dsa_mod_exp(dsa, t1, dsa->g, u1, dsa->pub_key, u2,
-                                    dsa->p, ctx, mont))
+        if (!dsa->meth->dsa_mod_exp(dsa, t1, dsa->params.g, u1, dsa->pub_key, u2,
+                                    dsa->params.p, ctx, mont))
             goto err;
     } else {
-        if (!BN_mod_exp2_mont(t1, dsa->g, u1, dsa->pub_key, u2, dsa->p, ctx,
-                              mont))
+        if (!BN_mod_exp2_mont(t1, dsa->params.g, u1, dsa->pub_key, u2,
+                              dsa->params.p, ctx, mont))
             goto err;
     }
 
     /* let u1 = u1 mod q */
-    if (!BN_mod(u1, t1, dsa->q, ctx))
+    if (!BN_mod(u1, t1, dsa->params.q, ctx))
         goto err;
 
     /*
@@ -413,6 +420,7 @@ static int dsa_do_verify(const unsigned char *dgst, int dgst_len,
 static int dsa_init(DSA *dsa)
 {
     dsa->flags |= DSA_FLAG_CACHE_MONT_P;
+    ffc_params_init(&dsa->params);
     return 1;
 }
 
diff --git a/crypto/dsa/dsa_sign.c b/crypto/dsa/dsa_sign.c
index d09aaea..d3e8cfa 100644
--- a/crypto/dsa/dsa_sign.c
+++ b/crypto/dsa/dsa_sign.c
@@ -115,7 +115,7 @@ int DSA_size(const DSA *dsa)
     int ret;
     DSA_SIG sig;
 
-    sig.r = sig.s = dsa->q;
+    sig.r = sig.s = dsa->params.q;
     ret = i2d_DSA_SIG(&sig, NULL);
 
     if (ret < 0)