Remove flags for disabling constant-time operations.

This removes support for DSA_FLAG_NO_EXP_CONSTTIME, DH_FLAG_NO_EXP_CONSTTIME,
and RSA_FLAG_NO_CONSTTIME flags, making all of these operations unconditionally
constant-time.

Based on the original patch by César Pereid.  ok beck@

16 files changed, 174 insertions, 354 deletions

diff --git a/src/lib/libcrypto/dh/dh.h b/src/lib/libcrypto/dh/dh.h
index a20467c9d0..631cd5c685 100644
--- a/src/lib/libcrypto/dh/dh.h
+++ b/src/lib/libcrypto/dh/dh.h
@@ -1,4 +1,4 @@
-/* $OpenBSD: dh.h,v 1.16 2014/06/12 15:49:28 deraadt Exp $ */
+/* $OpenBSD: dh.h,v 1.17 2016/06/30 02:02:06 bcook Exp $ */
 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
  * All rights reserved.
  *
@@ -78,13 +78,6 @@
 #endif
 
 #define DH_FLAG_CACHE_MONT_P     0x01
-#define DH_FLAG_NO_EXP_CONSTTIME 0x02 /* new with 0.9.7h; the built-in DH
-                                       * implementation now uses constant time
-                                       * modular exponentiation for secret exponents
-                                       * by default. This flag causes the
-                                       * faster variable sliding window method to
-                                       * be used for all exponents.
-                                       */
 
 /* If this flag is set the DH method is FIPS compliant and can be used
  * in FIPS mode. This is set in the validated module method. If an
diff --git a/src/lib/libcrypto/dh/dh_key.c b/src/lib/libcrypto/dh/dh_key.c
index 31bc7b3dfd..25e8968ef5 100644
--- a/src/lib/libcrypto/dh/dh_key.c
+++ b/src/lib/libcrypto/dh/dh_key.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: dh_key.c,v 1.23 2015/02/09 15:49:22 jsing Exp $ */
+/* $OpenBSD: dh_key.c,v 1.24 2016/06/30 02:02:06 bcook Exp $ */
 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
  * All rights reserved.
  *
@@ -147,21 +147,16 @@ generate_key(DH *dh)
         }
 
         {
-                BIGNUM local_prk;
-                BIGNUM *prk;
+                BIGNUM prk;
 
-                if ((dh->flags & DH_FLAG_NO_EXP_CONSTTIME) == 0) {
-                        BN_init(&local_prk);
-                        prk = &local_prk;
-                        BN_with_flags(prk, priv_key, BN_FLG_CONSTTIME);
-                } else
-                        prk = priv_key;
+                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->g, &prk, dh->p, ctx,
+                    mont)) {
                         goto err;
+                }
         }
-                
+
         dh->pub_key = pub_key;
         dh->priv_key = priv_key;
         ok = 1;
@@ -206,10 +201,9 @@ compute_key(unsigned char *key, const BIGNUM *pub_key, DH *dh)
         if (dh->flags & DH_FLAG_CACHE_MONT_P) {
                 mont = BN_MONT_CTX_set_locked(&dh->method_mont_p,
                     CRYPTO_LOCK_DH, dh->p, ctx);
-                if ((dh->flags & DH_FLAG_NO_EXP_CONSTTIME) == 0) {
-                        /* XXX */
-                        BN_set_flags(dh->priv_key, BN_FLG_CONSTTIME);
-                }
+
+                BN_set_flags(dh->priv_key, BN_FLG_CONSTTIME);
+
                 if (!mont)
                         goto err;
         }
@@ -238,16 +232,7 @@ static int
 dh_bn_mod_exp(const DH *dh, BIGNUM *r, const BIGNUM *a, const BIGNUM *p,
     const BIGNUM *m, BN_CTX *ctx, BN_MONT_CTX *m_ctx)
 {
-        /*
-         * If a is only one word long and constant time is false, use the faster
-         * exponenentiation function.
-         */
-        if (a->top == 1 && (dh->flags & DH_FLAG_NO_EXP_CONSTTIME) != 0) {
-                BN_ULONG A = a->d[0];
-
-                return BN_mod_exp_mont_word(r, A, p, m, ctx, m_ctx);
-        } else
-                return BN_mod_exp_mont(r, a, p, m, ctx, m_ctx);
+        return BN_mod_exp_mont(r, a, p, m, ctx, m_ctx);
 }
 
 static int
diff --git a/src/lib/libcrypto/dsa/dsa.h b/src/lib/libcrypto/dsa/dsa.h
index f7f81cfa94..b4d7c1ff0f 100644
--- a/src/lib/libcrypto/dsa/dsa.h
+++ b/src/lib/libcrypto/dsa/dsa.h
@@ -1,4 +1,4 @@
-/* $OpenBSD: dsa.h,v 1.20 2016/06/21 04:16:53 bcook Exp $ */
+/* $OpenBSD: dsa.h,v 1.21 2016/06/30 02:02:06 bcook Exp $ */
 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
  * All rights reserved.
  *
@@ -89,9 +89,6 @@
 #endif
 
 #define DSA_FLAG_CACHE_MONT_P   0x01
-#define DSA_FLAG_NO_EXP_CONSTTIME       0x00 /* Does nothing. Previously this switched off 
-                                              * constant time behaviour.
-                                              */
 
 /* If this flag is set the DSA method is FIPS compliant and can be used
  * in FIPS mode. This is set in the validated module method. If an
diff --git a/src/lib/libcrypto/dsa/dsa_key.c b/src/lib/libcrypto/dsa/dsa_key.c
index 4732c471ed..fc4eb9c433 100644
--- a/src/lib/libcrypto/dsa/dsa_key.c
+++ b/src/lib/libcrypto/dsa/dsa_key.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: dsa_key.c,v 1.21 2016/06/21 04:16:53 bcook Exp $ */
+/* $OpenBSD: dsa_key.c,v 1.22 2016/06/30 02:02:06 bcook Exp $ */
 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
  * All rights reserved.
  *
@@ -104,18 +104,12 @@ dsa_builtin_keygen(DSA *dsa)
                 pub_key=dsa->pub_key;
         
         {
-                BIGNUM *prk = BN_new();
+                BIGNUM prk;
 
-                if (prk == NULL)
-                        goto err;
-
-                BN_with_flags(prk, priv_key, BN_FLG_CONSTTIME);
+                BN_with_flags(&prk, priv_key, BN_FLG_CONSTTIME);
 
-                if (!BN_mod_exp(pub_key, dsa->g, prk, dsa->p, ctx)) {
-                        BN_free(prk);
+                if (!BN_mod_exp(pub_key, dsa->g, &prk, dsa->p, ctx))
                         goto err;
-                }
-                BN_free(prk);
         }
 
         dsa->priv_key = priv_key;
diff --git a/src/lib/libcrypto/rsa/rsa.h b/src/lib/libcrypto/rsa/rsa.h
index 4045a6cbf3..d240294809 100644
--- a/src/lib/libcrypto/rsa/rsa.h
+++ b/src/lib/libcrypto/rsa/rsa.h
@@ -1,4 +1,4 @@
-/* $OpenBSD: rsa.h,v 1.27 2015/02/14 15:10:39 miod Exp $ */
+/* $OpenBSD: rsa.h,v 1.28 2016/06/30 02:02:06 bcook Exp $ */
 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
  * All rights reserved.
  *
@@ -194,16 +194,6 @@ struct rsa_st {
  */
 #define RSA_FLAG_NO_BLINDING            0x0080
 
-/*
- * The built-in RSA implementation uses constant time operations by default
- * in private key operations, e.g., constant time modular exponentiation,
- * modular inverse without leaking branches, division without leaking branches.
- * This flag disables these constant time operations and results in faster RSA
- * private key operations.
- */
-#define RSA_FLAG_NO_CONSTTIME           0x0100
-
-
 #define EVP_PKEY_CTX_set_rsa_padding(ctx, pad) \
         EVP_PKEY_CTX_ctrl(ctx, EVP_PKEY_RSA, -1, EVP_PKEY_CTRL_RSA_PADDING, \
                                 pad, NULL)
diff --git a/src/lib/libcrypto/rsa/rsa_crpt.c b/src/lib/libcrypto/rsa/rsa_crpt.c
index 809dd14c92..b50e4a4a6f 100644
--- a/src/lib/libcrypto/rsa/rsa_crpt.c
+++ b/src/lib/libcrypto/rsa/rsa_crpt.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: rsa_crpt.c,v 1.14 2015/02/11 03:19:37 doug Exp $ */
+/* $OpenBSD: rsa_crpt.c,v 1.15 2016/06/30 02:02:06 bcook Exp $ */
 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
  * All rights reserved.
  *
@@ -169,8 +169,8 @@ err:
 BN_BLINDING *
 RSA_setup_blinding(RSA *rsa, BN_CTX *in_ctx)
 {
-        BIGNUM local_n;
-        BIGNUM *e, *n;
+        BIGNUM *e;
+        BIGNUM n;
         BN_CTX *ctx;
         BN_BLINDING *ret = NULL;
 
@@ -192,15 +192,11 @@ RSA_setup_blinding(RSA *rsa, BN_CTX *in_ctx)
         } else
                 e = rsa->e;
 
-        if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME)) {
-                /* Set BN_FLG_CONSTTIME flag */
-                n = &local_n;
-                BN_with_flags(n, rsa->n, BN_FLG_CONSTTIME);
-        } else
-                n = rsa->n;
+        BN_with_flags(&n, rsa->n, BN_FLG_CONSTTIME);
 
-        ret = BN_BLINDING_create_param(NULL, e, n, ctx, rsa->meth->bn_mod_exp,
+        ret = BN_BLINDING_create_param(NULL, e, &n, ctx, rsa->meth->bn_mod_exp,
             rsa->_method_mod_n);
+
         if (ret == NULL) {
                 RSAerr(RSA_F_RSA_SETUP_BLINDING, ERR_R_BN_LIB);
                 goto err;
diff --git a/src/lib/libcrypto/rsa/rsa_eay.c b/src/lib/libcrypto/rsa/rsa_eay.c
index 76863e7220..6edfd7e5fd 100644
--- a/src/lib/libcrypto/rsa/rsa_eay.c
+++ b/src/lib/libcrypto/rsa/rsa_eay.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: rsa_eay.c,v 1.40 2015/09/10 15:56:25 jsing Exp $ */
+/* $OpenBSD: rsa_eay.c,v 1.41 2016/06/30 02:02:06 bcook Exp $ */
 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
  * All rights reserved.
  *
@@ -177,11 +177,13 @@ RSA_eay_public_encrypt(int flen, const unsigned char *from, unsigned char *to,
 
         if ((ctx = BN_CTX_new()) == NULL)
                 goto err;
+
         BN_CTX_start(ctx);
         f = BN_CTX_get(ctx);
         ret = BN_CTX_get(ctx);
         num = BN_num_bytes(rsa->n);
         buf = malloc(num);
+
         if (f == NULL || ret == NULL || buf == NULL) {
                 RSAerr(RSA_F_RSA_EAY_PUBLIC_ENCRYPT, ERR_R_MALLOC_FAILURE);
                 goto err;
@@ -362,11 +364,13 @@ RSA_eay_private_encrypt(int flen, const unsigned char *from, unsigned char *to,
 
         if ((ctx = BN_CTX_new()) == NULL)
                 goto err;
+
         BN_CTX_start(ctx);
         f = BN_CTX_get(ctx);
         ret = BN_CTX_get(ctx);
         num = BN_num_bytes(rsa->n);
         buf = malloc(num);
+
         if (f == NULL || ret == NULL || buf == NULL) {
                 RSAerr(RSA_F_RSA_EAY_PRIVATE_ENCRYPT, ERR_R_MALLOC_FAILURE);
                 goto err;
@@ -426,24 +430,19 @@ RSA_eay_private_encrypt(int flen, const unsigned char *from, unsigned char *to,
                 if (!rsa->meth->rsa_mod_exp(ret, f, rsa, ctx))
                         goto err;
         } else {
-                BIGNUM local_d;
-                BIGNUM *d = NULL;
+                BIGNUM d;
 
-                if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME)) {
-                        BN_init(&local_d);
-                        d = &local_d;
-                        BN_with_flags(d, rsa->d, BN_FLG_CONSTTIME);
-                } else
-                        d = rsa->d;
+                BN_with_flags(&d, rsa->d, BN_FLG_CONSTTIME);
 
                 if (rsa->flags & RSA_FLAG_CACHE_PUBLIC)
                         if (!BN_MONT_CTX_set_locked(&rsa->_method_mod_n,
                             CRYPTO_LOCK_RSA, rsa->n, ctx))
                                 goto err;
 
-                if (!rsa->meth->bn_mod_exp(ret, f, d, rsa->n, ctx,
-                    rsa->_method_mod_n))
+                if (!rsa->meth->bn_mod_exp(ret, f, &d, rsa->n, ctx,
+                    rsa->_method_mod_n)) {
                         goto err;
+                }
         }
 
         if (blinding)
@@ -499,11 +498,13 @@ RSA_eay_private_decrypt(int flen, const unsigned char *from, unsigned char *to,
 
         if ((ctx = BN_CTX_new()) == NULL)
                 goto err;
+
         BN_CTX_start(ctx);
         f = BN_CTX_get(ctx);
         ret = BN_CTX_get(ctx);
         num = BN_num_bytes(rsa->n);
         buf = malloc(num);
+
         if (!f || !ret || !buf) {
                 RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT, ERR_R_MALLOC_FAILURE);
                 goto err;
@@ -553,22 +554,19 @@ RSA_eay_private_decrypt(int flen, const unsigned char *from, unsigned char *to,
                 if (!rsa->meth->rsa_mod_exp(ret, f, rsa, ctx))
                         goto err;
         } else {
-                BIGNUM local_d;
-                BIGNUM *d = NULL;
+                BIGNUM d;
 
-                if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME)) {
-                        d = &local_d;
-                        BN_with_flags(d, rsa->d, BN_FLG_CONSTTIME);
-                } else
-                        d = rsa->d;
+                BN_with_flags(&d, rsa->d, BN_FLG_CONSTTIME);
 
                 if (rsa->flags & RSA_FLAG_CACHE_PUBLIC)
                         if (!BN_MONT_CTX_set_locked(&rsa->_method_mod_n,
                             CRYPTO_LOCK_RSA, rsa->n, ctx))
                                 goto err;
-                if (!rsa->meth->bn_mod_exp(ret, f, d, rsa->n, ctx,
-                    rsa->_method_mod_n))
+
+                if (!rsa->meth->bn_mod_exp(ret, f, &d, rsa->n, ctx,
+                    rsa->_method_mod_n)) {
                         goto err;
+                }
         }
 
         if (blinding)
@@ -645,11 +643,13 @@ RSA_eay_public_decrypt(int flen, const unsigned char *from, unsigned char *to,
 
         if ((ctx = BN_CTX_new()) == NULL)
                 goto err;
+
         BN_CTX_start(ctx);
         f = BN_CTX_get(ctx);
         ret = BN_CTX_get(ctx);
         num = BN_num_bytes(rsa->n);
         buf = malloc(num);
+
         if (!f || !ret || !buf) {
                 RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT, ERR_R_MALLOC_FAILURE);
                 goto err;
@@ -723,8 +723,7 @@ static int
 RSA_eay_mod_exp(BIGNUM *r0, const BIGNUM *I, RSA *rsa, BN_CTX *ctx)
 {
         BIGNUM *r1, *m1, *vrfy;
-        BIGNUM local_dmp1, local_dmq1, local_c, local_r1;
-        BIGNUM *dmp1, *dmq1, *c, *pr1;
+        BIGNUM dmp1, dmq1, c, pr1;
         int ret = 0;
 
         BN_CTX_start(ctx);
@@ -737,33 +736,22 @@ RSA_eay_mod_exp(BIGNUM *r0, const BIGNUM *I, RSA *rsa, BN_CTX *ctx)
         }
 
         {
-                BIGNUM local_p, local_q;
-                BIGNUM *p = NULL, *q = NULL;
+                BIGNUM p, q;
 
                 /*
                  * Make sure BN_mod_inverse in Montgomery intialization uses the
-                 * BN_FLG_CONSTTIME flag (unless RSA_FLAG_NO_CONSTTIME is set)
+                 * BN_FLG_CONSTTIME flag
                  */
-                if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME)) {
-                        BN_init(&local_p);
-                        p = &local_p;
-                        BN_with_flags(p, rsa->p, BN_FLG_CONSTTIME);
-
-                        BN_init(&local_q);
-                        q = &local_q;
-                        BN_with_flags(q, rsa->q, BN_FLG_CONSTTIME);
-                } else {
-                        p = rsa->p;
-                        q = rsa->q;
-                }
+                BN_with_flags(&p, rsa->p, BN_FLG_CONSTTIME);
+                BN_with_flags(&q, rsa->q, BN_FLG_CONSTTIME);
 
                 if (rsa->flags & RSA_FLAG_CACHE_PRIVATE) {
                         if (!BN_MONT_CTX_set_locked(&rsa->_method_mod_p,
-                            CRYPTO_LOCK_RSA, p, ctx))
-                                goto err;
-                        if (!BN_MONT_CTX_set_locked(&rsa->_method_mod_q,
-                            CRYPTO_LOCK_RSA, q, ctx))
+                             CRYPTO_LOCK_RSA, &p, ctx) ||
+                            !BN_MONT_CTX_set_locked(&rsa->_method_mod_q,
+                             CRYPTO_LOCK_RSA, &q, ctx)) {
                                 goto err;
+                        }
                 }
         }
 
@@ -773,49 +761,34 @@ RSA_eay_mod_exp(BIGNUM *r0, const BIGNUM *I, RSA *rsa, BN_CTX *ctx)
                         goto err;
 
         /* compute I mod q */
-        if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME)) {
-                c = &local_c;
-                BN_with_flags(c, I, BN_FLG_CONSTTIME);
-                if (!BN_mod(r1, c, rsa->q, ctx))
-                        goto err;
-        } else {
-                if (!BN_mod(r1, I, rsa->q, ctx))
-                        goto err;
-        }
+        BN_with_flags(&c, I, BN_FLG_CONSTTIME);
+
+        if (!BN_mod(r1, &c, rsa->q, ctx))
+                goto err;
 
         /* compute r1^dmq1 mod q */
-        if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME)) {
-                dmq1 = &local_dmq1;
-                BN_with_flags(dmq1, rsa->dmq1, BN_FLG_CONSTTIME);
-        } else
-                dmq1 = rsa->dmq1;
-        if (!rsa->meth->bn_mod_exp(m1, r1, dmq1, rsa->q, ctx,
+        BN_with_flags(&dmq1, rsa->dmq1, BN_FLG_CONSTTIME);
+
+        if (!rsa->meth->bn_mod_exp(m1, r1, &dmq1, rsa->q, ctx,
             rsa->_method_mod_q))
                 goto err;
 
         /* compute I mod p */
-        if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME)) {
-                c = &local_c;
-                BN_with_flags(c, I, BN_FLG_CONSTTIME);
-                if (!BN_mod(r1, c, rsa->p, ctx))
-                        goto err;
-        } else {
-                if (!BN_mod(r1, I, rsa->p, ctx))
-                        goto err;
-        }
+        BN_with_flags(&c, I, BN_FLG_CONSTTIME);
+
+        if (!BN_mod(r1, &c, rsa->p, ctx))
+                goto err;
 
         /* compute r1^dmp1 mod p */
-        if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME)) {
-                dmp1 = &local_dmp1;
-                BN_with_flags(dmp1, rsa->dmp1, BN_FLG_CONSTTIME);
-        } else
-                dmp1 = rsa->dmp1;
-        if (!rsa->meth->bn_mod_exp(r0, r1, dmp1, rsa->p, ctx,
+        BN_with_flags(&dmp1, rsa->dmp1, BN_FLG_CONSTTIME);
+
+        if (!rsa->meth->bn_mod_exp(r0, r1, &dmp1, rsa->p, ctx,
             rsa->_method_mod_p))
                 goto err;
 
         if (!BN_sub(r0, r0, m1))
                 goto err;
+
         /*
          * This will help stop the size of r0 increasing, which does
          * affect the multiply if it optimised for a power of 2 size
@@ -828,12 +801,9 @@ RSA_eay_mod_exp(BIGNUM *r0, const BIGNUM *I, RSA *rsa, BN_CTX *ctx)
                 goto err;
 
         /* Turn BN_FLG_CONSTTIME flag on before division operation */
-        if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME)) {
-                pr1 = &local_r1;
-                BN_with_flags(pr1, r1, BN_FLG_CONSTTIME);
-        } else
-                pr1 = r1;
-        if (!BN_mod(r0, pr1, rsa->p, ctx))
+        BN_with_flags(&pr1, r1, BN_FLG_CONSTTIME);
+
+        if (!BN_mod(r0, &pr1, rsa->p, ctx))
                 goto err;
 
         /*
@@ -875,18 +845,14 @@ RSA_eay_mod_exp(BIGNUM *r0, const BIGNUM *I, RSA *rsa, BN_CTX *ctx)
                          * miscalculated CRT output, just do a raw (slower)
                          * mod_exp and return that instead.
                          */
+                        BIGNUM d;
 
-                        BIGNUM local_d;
-                        BIGNUM *d = NULL;
+                        BN_with_flags(&d, rsa->d, BN_FLG_CONSTTIME);
 
-                        if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME)) {
-                                d = &local_d;
-                                BN_with_flags(d, rsa->d, BN_FLG_CONSTTIME);
-                        } else
-                                d = rsa->d;
-                        if (!rsa->meth->bn_mod_exp(r0, I, d, rsa->n, ctx,
-                            rsa->_method_mod_n))
+                        if (!rsa->meth->bn_mod_exp(r0, I, &d, rsa->n, ctx,
+                            rsa->_method_mod_n)) {
                                 goto err;
+                        }
                 }
         }
         ret = 1;
diff --git a/src/lib/libcrypto/rsa/rsa_gen.c b/src/lib/libcrypto/rsa/rsa_gen.c
index f6f051c442..d46f4f2478 100644
--- a/src/lib/libcrypto/rsa/rsa_gen.c
+++ b/src/lib/libcrypto/rsa/rsa_gen.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: rsa_gen.c,v 1.17 2015/02/09 15:49:22 jsing Exp $ */
+/* $OpenBSD: rsa_gen.c,v 1.18 2016/06/30 02:02:06 bcook Exp $ */
 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
  * All rights reserved.
  *
@@ -90,8 +90,7 @@ static int
 rsa_builtin_keygen(RSA *rsa, int bits, BIGNUM *e_value, BN_GENCB *cb)
 {
         BIGNUM *r0 = NULL, *r1 = NULL, *r2 = NULL, *r3 = NULL, *tmp;
-        BIGNUM local_r0, local_d, local_p;
-        BIGNUM *pr0, *d, *p;
+        BIGNUM pr0, d, p;
         int bitsp, bitsq, ok = -1, n = 0;
         BN_CTX *ctx = NULL;
 
@@ -193,36 +192,26 @@ rsa_builtin_keygen(RSA *rsa, int bits, BIGNUM *e_value, BN_GENCB *cb)
                 goto err;
         if (!BN_mul(r0, r1, r2, ctx))                   /* (p-1)(q-1) */
                 goto err;
-        if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME)) {
-                pr0 = &local_r0;
-                BN_with_flags(pr0, r0, BN_FLG_CONSTTIME);
-        } else
-                pr0 = r0;
-        if (!BN_mod_inverse(rsa->d, rsa->e, pr0, ctx))  /* d */
+
+        BN_with_flags(&pr0, r0, BN_FLG_CONSTTIME);
+
+        if (!BN_mod_inverse(rsa->d, rsa->e, &pr0, ctx)) /* d */
                 goto err;
 
         /* set up d for correct BN_FLG_CONSTTIME flag */
-        if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME)) {
-                d = &local_d;
-                BN_with_flags(d, rsa->d, BN_FLG_CONSTTIME);
-        } else
-                d = rsa->d;
+        BN_with_flags(&d, rsa->d, BN_FLG_CONSTTIME);
 
         /* calculate d mod (p-1) */
-        if (!BN_mod(rsa->dmp1, d, r1, ctx))
+        if (!BN_mod(rsa->dmp1, &d, r1, ctx))
                 goto err;
 
         /* calculate d mod (q-1) */
-        if (!BN_mod(rsa->dmq1, d, r2, ctx))
+        if (!BN_mod(rsa->dmq1, &d, r2, ctx))
                 goto err;
 
         /* calculate inverse of q mod p */
-        if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME)) {
-                p = &local_p;
-                BN_with_flags(p, rsa->p, BN_FLG_CONSTTIME);
-        } else
-                p = rsa->p;
-        if (!BN_mod_inverse(rsa->iqmp, rsa->q, p, ctx))
+        BN_with_flags(&p, rsa->p, BN_FLG_CONSTTIME);
+        if (!BN_mod_inverse(rsa->iqmp, rsa->q, &p, ctx))
                 goto err;
 
         ok = 1;
diff --git a/src/lib/libssl/src/crypto/dh/dh.h b/src/lib/libssl/src/crypto/dh/dh.h
index a20467c9d0..631cd5c685 100644
--- a/src/lib/libssl/src/crypto/dh/dh.h
+++ b/src/lib/libssl/src/crypto/dh/dh.h
@@ -1,4 +1,4 @@
-/* $OpenBSD: dh.h,v 1.16 2014/06/12 15:49:28 deraadt Exp $ */
+/* $OpenBSD: dh.h,v 1.17 2016/06/30 02:02:06 bcook Exp $ */
 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
  * All rights reserved.
  *
@@ -78,13 +78,6 @@
 #endif
 
 #define DH_FLAG_CACHE_MONT_P     0x01
-#define DH_FLAG_NO_EXP_CONSTTIME 0x02 /* new with 0.9.7h; the built-in DH
-                                       * implementation now uses constant time
-                                       * modular exponentiation for secret exponents
-                                       * by default. This flag causes the
-                                       * faster variable sliding window method to
-                                       * be used for all exponents.
-                                       */
 
 /* If this flag is set the DH method is FIPS compliant and can be used
  * in FIPS mode. This is set in the validated module method. If an
diff --git a/src/lib/libssl/src/crypto/dh/dh_key.c b/src/lib/libssl/src/crypto/dh/dh_key.c
index 31bc7b3dfd..25e8968ef5 100644
--- a/src/lib/libssl/src/crypto/dh/dh_key.c
+++ b/src/lib/libssl/src/crypto/dh/dh_key.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: dh_key.c,v 1.23 2015/02/09 15:49:22 jsing Exp $ */
+/* $OpenBSD: dh_key.c,v 1.24 2016/06/30 02:02:06 bcook Exp $ */
 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
  * All rights reserved.
  *
@@ -147,21 +147,16 @@ generate_key(DH *dh)
         }
 
         {
-                BIGNUM local_prk;
-                BIGNUM *prk;
+                BIGNUM prk;
 
-                if ((dh->flags & DH_FLAG_NO_EXP_CONSTTIME) == 0) {
-                        BN_init(&local_prk);
-                        prk = &local_prk;
-                        BN_with_flags(prk, priv_key, BN_FLG_CONSTTIME);
-                } else
-                        prk = priv_key;
+                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->g, &prk, dh->p, ctx,
+                    mont)) {
                         goto err;
+                }
         }
-                
+
         dh->pub_key = pub_key;
         dh->priv_key = priv_key;
         ok = 1;
@@ -206,10 +201,9 @@ compute_key(unsigned char *key, const BIGNUM *pub_key, DH *dh)
         if (dh->flags & DH_FLAG_CACHE_MONT_P) {
                 mont = BN_MONT_CTX_set_locked(&dh->method_mont_p,
                     CRYPTO_LOCK_DH, dh->p, ctx);
-                if ((dh->flags & DH_FLAG_NO_EXP_CONSTTIME) == 0) {
-                        /* XXX */
-                        BN_set_flags(dh->priv_key, BN_FLG_CONSTTIME);
-                }
+
+                BN_set_flags(dh->priv_key, BN_FLG_CONSTTIME);
+
                 if (!mont)
                         goto err;
         }
@@ -238,16 +232,7 @@ static int
 dh_bn_mod_exp(const DH *dh, BIGNUM *r, const BIGNUM *a, const BIGNUM *p,
     const BIGNUM *m, BN_CTX *ctx, BN_MONT_CTX *m_ctx)
 {
-        /*
-         * If a is only one word long and constant time is false, use the faster
-         * exponenentiation function.
-         */
-        if (a->top == 1 && (dh->flags & DH_FLAG_NO_EXP_CONSTTIME) != 0) {
-                BN_ULONG A = a->d[0];
-
-                return BN_mod_exp_mont_word(r, A, p, m, ctx, m_ctx);
-        } else
-                return BN_mod_exp_mont(r, a, p, m, ctx, m_ctx);
+        return BN_mod_exp_mont(r, a, p, m, ctx, m_ctx);
 }
 
 static int
diff --git a/src/lib/libssl/src/crypto/dsa/dsa.h b/src/lib/libssl/src/crypto/dsa/dsa.h
index f7f81cfa94..b4d7c1ff0f 100644
--- a/src/lib/libssl/src/crypto/dsa/dsa.h
+++ b/src/lib/libssl/src/crypto/dsa/dsa.h
@@ -1,4 +1,4 @@
-/* $OpenBSD: dsa.h,v 1.20 2016/06/21 04:16:53 bcook Exp $ */
+/* $OpenBSD: dsa.h,v 1.21 2016/06/30 02:02:06 bcook Exp $ */
 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
  * All rights reserved.
  *
@@ -89,9 +89,6 @@
 #endif
 
 #define DSA_FLAG_CACHE_MONT_P   0x01
-#define DSA_FLAG_NO_EXP_CONSTTIME       0x00 /* Does nothing. Previously this switched off 
-                                              * constant time behaviour.
-                                              */
 
 /* If this flag is set the DSA method is FIPS compliant and can be used
  * in FIPS mode. This is set in the validated module method. If an
diff --git a/src/lib/libssl/src/crypto/dsa/dsa_key.c b/src/lib/libssl/src/crypto/dsa/dsa_key.c
index 4732c471ed..fc4eb9c433 100644
--- a/src/lib/libssl/src/crypto/dsa/dsa_key.c
+++ b/src/lib/libssl/src/crypto/dsa/dsa_key.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: dsa_key.c,v 1.21 2016/06/21 04:16:53 bcook Exp $ */
+/* $OpenBSD: dsa_key.c,v 1.22 2016/06/30 02:02:06 bcook Exp $ */
 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
  * All rights reserved.
  *
@@ -104,18 +104,12 @@ dsa_builtin_keygen(DSA *dsa)
                 pub_key=dsa->pub_key;
         
         {
-                BIGNUM *prk = BN_new();
+                BIGNUM prk;
 
-                if (prk == NULL)
-                        goto err;
-
-                BN_with_flags(prk, priv_key, BN_FLG_CONSTTIME);
+                BN_with_flags(&prk, priv_key, BN_FLG_CONSTTIME);
 
-                if (!BN_mod_exp(pub_key, dsa->g, prk, dsa->p, ctx)) {
-                        BN_free(prk);
+                if (!BN_mod_exp(pub_key, dsa->g, &prk, dsa->p, ctx))
                         goto err;
-                }
-                BN_free(prk);
         }
 
         dsa->priv_key = priv_key;
diff --git a/src/lib/libssl/src/crypto/rsa/rsa.h b/src/lib/libssl/src/crypto/rsa/rsa.h
index 4045a6cbf3..d240294809 100644
--- a/src/lib/libssl/src/crypto/rsa/rsa.h
+++ b/src/lib/libssl/src/crypto/rsa/rsa.h
@@ -1,4 +1,4 @@
-/* $OpenBSD: rsa.h,v 1.27 2015/02/14 15:10:39 miod Exp $ */
+/* $OpenBSD: rsa.h,v 1.28 2016/06/30 02:02:06 bcook Exp $ */
 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
  * All rights reserved.
  *
@@ -194,16 +194,6 @@ struct rsa_st {
  */
 #define RSA_FLAG_NO_BLINDING            0x0080
 
-/*
- * The built-in RSA implementation uses constant time operations by default
- * in private key operations, e.g., constant time modular exponentiation,
- * modular inverse without leaking branches, division without leaking branches.
- * This flag disables these constant time operations and results in faster RSA
- * private key operations.
- */
-#define RSA_FLAG_NO_CONSTTIME           0x0100
-
-
 #define EVP_PKEY_CTX_set_rsa_padding(ctx, pad) \
         EVP_PKEY_CTX_ctrl(ctx, EVP_PKEY_RSA, -1, EVP_PKEY_CTRL_RSA_PADDING, \
                                 pad, NULL)
diff --git a/src/lib/libssl/src/crypto/rsa/rsa_crpt.c b/src/lib/libssl/src/crypto/rsa/rsa_crpt.c
index 809dd14c92..b50e4a4a6f 100644
--- a/src/lib/libssl/src/crypto/rsa/rsa_crpt.c
+++ b/src/lib/libssl/src/crypto/rsa/rsa_crpt.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: rsa_crpt.c,v 1.14 2015/02/11 03:19:37 doug Exp $ */
+/* $OpenBSD: rsa_crpt.c,v 1.15 2016/06/30 02:02:06 bcook Exp $ */
 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
  * All rights reserved.
  *
@@ -169,8 +169,8 @@ err:
 BN_BLINDING *
 RSA_setup_blinding(RSA *rsa, BN_CTX *in_ctx)
 {
-        BIGNUM local_n;
-        BIGNUM *e, *n;
+        BIGNUM *e;
+        BIGNUM n;
         BN_CTX *ctx;
         BN_BLINDING *ret = NULL;
 
@@ -192,15 +192,11 @@ RSA_setup_blinding(RSA *rsa, BN_CTX *in_ctx)
         } else
                 e = rsa->e;
 
-        if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME)) {
-                /* Set BN_FLG_CONSTTIME flag */
-                n = &local_n;
-                BN_with_flags(n, rsa->n, BN_FLG_CONSTTIME);
-        } else
-                n = rsa->n;
+        BN_with_flags(&n, rsa->n, BN_FLG_CONSTTIME);
 
-        ret = BN_BLINDING_create_param(NULL, e, n, ctx, rsa->meth->bn_mod_exp,
+        ret = BN_BLINDING_create_param(NULL, e, &n, ctx, rsa->meth->bn_mod_exp,
             rsa->_method_mod_n);
+
         if (ret == NULL) {
                 RSAerr(RSA_F_RSA_SETUP_BLINDING, ERR_R_BN_LIB);
                 goto err;
diff --git a/src/lib/libssl/src/crypto/rsa/rsa_eay.c b/src/lib/libssl/src/crypto/rsa/rsa_eay.c
index 76863e7220..6edfd7e5fd 100644
--- a/src/lib/libssl/src/crypto/rsa/rsa_eay.c
+++ b/src/lib/libssl/src/crypto/rsa/rsa_eay.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: rsa_eay.c,v 1.40 2015/09/10 15:56:25 jsing Exp $ */
+/* $OpenBSD: rsa_eay.c,v 1.41 2016/06/30 02:02:06 bcook Exp $ */
 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
  * All rights reserved.
  *
@@ -177,11 +177,13 @@ RSA_eay_public_encrypt(int flen, const unsigned char *from, unsigned char *to,
 
         if ((ctx = BN_CTX_new()) == NULL)
                 goto err;
+
         BN_CTX_start(ctx);
         f = BN_CTX_get(ctx);
         ret = BN_CTX_get(ctx);
         num = BN_num_bytes(rsa->n);
         buf = malloc(num);
+
         if (f == NULL || ret == NULL || buf == NULL) {
                 RSAerr(RSA_F_RSA_EAY_PUBLIC_ENCRYPT, ERR_R_MALLOC_FAILURE);
                 goto err;
@@ -362,11 +364,13 @@ RSA_eay_private_encrypt(int flen, const unsigned char *from, unsigned char *to,
 
         if ((ctx = BN_CTX_new()) == NULL)
                 goto err;
+
         BN_CTX_start(ctx);
         f = BN_CTX_get(ctx);
         ret = BN_CTX_get(ctx);
         num = BN_num_bytes(rsa->n);
         buf = malloc(num);
+
         if (f == NULL || ret == NULL || buf == NULL) {
                 RSAerr(RSA_F_RSA_EAY_PRIVATE_ENCRYPT, ERR_R_MALLOC_FAILURE);
                 goto err;
@@ -426,24 +430,19 @@ RSA_eay_private_encrypt(int flen, const unsigned char *from, unsigned char *to,
                 if (!rsa->meth->rsa_mod_exp(ret, f, rsa, ctx))
                         goto err;
         } else {
-                BIGNUM local_d;
-                BIGNUM *d = NULL;
+                BIGNUM d;
 
-                if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME)) {
-                        BN_init(&local_d);
-                        d = &local_d;
-                        BN_with_flags(d, rsa->d, BN_FLG_CONSTTIME);
-                } else
-                        d = rsa->d;
+                BN_with_flags(&d, rsa->d, BN_FLG_CONSTTIME);
 
                 if (rsa->flags & RSA_FLAG_CACHE_PUBLIC)
                         if (!BN_MONT_CTX_set_locked(&rsa->_method_mod_n,
                             CRYPTO_LOCK_RSA, rsa->n, ctx))
                                 goto err;
 
-                if (!rsa->meth->bn_mod_exp(ret, f, d, rsa->n, ctx,
-                    rsa->_method_mod_n))
+                if (!rsa->meth->bn_mod_exp(ret, f, &d, rsa->n, ctx,
+                    rsa->_method_mod_n)) {
                         goto err;
+                }
         }
 
         if (blinding)
@@ -499,11 +498,13 @@ RSA_eay_private_decrypt(int flen, const unsigned char *from, unsigned char *to,
 
         if ((ctx = BN_CTX_new()) == NULL)
                 goto err;
+
         BN_CTX_start(ctx);
         f = BN_CTX_get(ctx);
         ret = BN_CTX_get(ctx);
         num = BN_num_bytes(rsa->n);
         buf = malloc(num);
+
         if (!f || !ret || !buf) {
                 RSAerr(RSA_F_RSA_EAY_PRIVATE_DECRYPT, ERR_R_MALLOC_FAILURE);
                 goto err;
@@ -553,22 +554,19 @@ RSA_eay_private_decrypt(int flen, const unsigned char *from, unsigned char *to,
                 if (!rsa->meth->rsa_mod_exp(ret, f, rsa, ctx))
                         goto err;
         } else {
-                BIGNUM local_d;
-                BIGNUM *d = NULL;
+                BIGNUM d;
 
-                if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME)) {
-                        d = &local_d;
-                        BN_with_flags(d, rsa->d, BN_FLG_CONSTTIME);
-                } else
-                        d = rsa->d;
+                BN_with_flags(&d, rsa->d, BN_FLG_CONSTTIME);
 
                 if (rsa->flags & RSA_FLAG_CACHE_PUBLIC)
                         if (!BN_MONT_CTX_set_locked(&rsa->_method_mod_n,
                             CRYPTO_LOCK_RSA, rsa->n, ctx))
                                 goto err;
-                if (!rsa->meth->bn_mod_exp(ret, f, d, rsa->n, ctx,
-                    rsa->_method_mod_n))
+
+                if (!rsa->meth->bn_mod_exp(ret, f, &d, rsa->n, ctx,
+                    rsa->_method_mod_n)) {
                         goto err;
+                }
         }
 
         if (blinding)
@@ -645,11 +643,13 @@ RSA_eay_public_decrypt(int flen, const unsigned char *from, unsigned char *to,
 
         if ((ctx = BN_CTX_new()) == NULL)
                 goto err;
+
         BN_CTX_start(ctx);
         f = BN_CTX_get(ctx);
         ret = BN_CTX_get(ctx);
         num = BN_num_bytes(rsa->n);
         buf = malloc(num);
+
         if (!f || !ret || !buf) {
                 RSAerr(RSA_F_RSA_EAY_PUBLIC_DECRYPT, ERR_R_MALLOC_FAILURE);
                 goto err;
@@ -723,8 +723,7 @@ static int
 RSA_eay_mod_exp(BIGNUM *r0, const BIGNUM *I, RSA *rsa, BN_CTX *ctx)
 {
         BIGNUM *r1, *m1, *vrfy;
-        BIGNUM local_dmp1, local_dmq1, local_c, local_r1;
-        BIGNUM *dmp1, *dmq1, *c, *pr1;
+        BIGNUM dmp1, dmq1, c, pr1;
         int ret = 0;
 
         BN_CTX_start(ctx);
@@ -737,33 +736,22 @@ RSA_eay_mod_exp(BIGNUM *r0, const BIGNUM *I, RSA *rsa, BN_CTX *ctx)
         }
 
         {
-                BIGNUM local_p, local_q;
-                BIGNUM *p = NULL, *q = NULL;
+                BIGNUM p, q;
 
                 /*
                  * Make sure BN_mod_inverse in Montgomery intialization uses the
-                 * BN_FLG_CONSTTIME flag (unless RSA_FLAG_NO_CONSTTIME is set)
+                 * BN_FLG_CONSTTIME flag
                  */
-                if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME)) {
-                        BN_init(&local_p);
-                        p = &local_p;
-                        BN_with_flags(p, rsa->p, BN_FLG_CONSTTIME);
-
-                        BN_init(&local_q);
-                        q = &local_q;
-                        BN_with_flags(q, rsa->q, BN_FLG_CONSTTIME);
-                } else {
-                        p = rsa->p;
-                        q = rsa->q;
-                }
+                BN_with_flags(&p, rsa->p, BN_FLG_CONSTTIME);
+                BN_with_flags(&q, rsa->q, BN_FLG_CONSTTIME);
 
                 if (rsa->flags & RSA_FLAG_CACHE_PRIVATE) {
                         if (!BN_MONT_CTX_set_locked(&rsa->_method_mod_p,
-                            CRYPTO_LOCK_RSA, p, ctx))
-                                goto err;
-                        if (!BN_MONT_CTX_set_locked(&rsa->_method_mod_q,
-                            CRYPTO_LOCK_RSA, q, ctx))
+                             CRYPTO_LOCK_RSA, &p, ctx) ||
+                            !BN_MONT_CTX_set_locked(&rsa->_method_mod_q,
+                             CRYPTO_LOCK_RSA, &q, ctx)) {
                                 goto err;
+                        }
                 }
         }
 
@@ -773,49 +761,34 @@ RSA_eay_mod_exp(BIGNUM *r0, const BIGNUM *I, RSA *rsa, BN_CTX *ctx)
                         goto err;
 
         /* compute I mod q */
-        if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME)) {
-                c = &local_c;
-                BN_with_flags(c, I, BN_FLG_CONSTTIME);
-                if (!BN_mod(r1, c, rsa->q, ctx))
-                        goto err;
-        } else {
-                if (!BN_mod(r1, I, rsa->q, ctx))
-                        goto err;
-        }
+        BN_with_flags(&c, I, BN_FLG_CONSTTIME);
+
+        if (!BN_mod(r1, &c, rsa->q, ctx))
+                goto err;
 
         /* compute r1^dmq1 mod q */
-        if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME)) {
-                dmq1 = &local_dmq1;
-                BN_with_flags(dmq1, rsa->dmq1, BN_FLG_CONSTTIME);
-        } else
-                dmq1 = rsa->dmq1;
-        if (!rsa->meth->bn_mod_exp(m1, r1, dmq1, rsa->q, ctx,
+        BN_with_flags(&dmq1, rsa->dmq1, BN_FLG_CONSTTIME);
+
+        if (!rsa->meth->bn_mod_exp(m1, r1, &dmq1, rsa->q, ctx,
             rsa->_method_mod_q))
                 goto err;
 
         /* compute I mod p */
-        if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME)) {
-                c = &local_c;
-                BN_with_flags(c, I, BN_FLG_CONSTTIME);
-                if (!BN_mod(r1, c, rsa->p, ctx))
-                        goto err;
-        } else {
-                if (!BN_mod(r1, I, rsa->p, ctx))
-                        goto err;
-        }
+        BN_with_flags(&c, I, BN_FLG_CONSTTIME);
+
+        if (!BN_mod(r1, &c, rsa->p, ctx))
+                goto err;
 
         /* compute r1^dmp1 mod p */
-        if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME)) {
-                dmp1 = &local_dmp1;
-                BN_with_flags(dmp1, rsa->dmp1, BN_FLG_CONSTTIME);
-        } else
-                dmp1 = rsa->dmp1;
-        if (!rsa->meth->bn_mod_exp(r0, r1, dmp1, rsa->p, ctx,
+        BN_with_flags(&dmp1, rsa->dmp1, BN_FLG_CONSTTIME);
+
+        if (!rsa->meth->bn_mod_exp(r0, r1, &dmp1, rsa->p, ctx,
             rsa->_method_mod_p))
                 goto err;
 
         if (!BN_sub(r0, r0, m1))
                 goto err;
+
         /*
          * This will help stop the size of r0 increasing, which does
          * affect the multiply if it optimised for a power of 2 size
@@ -828,12 +801,9 @@ RSA_eay_mod_exp(BIGNUM *r0, const BIGNUM *I, RSA *rsa, BN_CTX *ctx)
                 goto err;
 
         /* Turn BN_FLG_CONSTTIME flag on before division operation */
-        if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME)) {
-                pr1 = &local_r1;
-                BN_with_flags(pr1, r1, BN_FLG_CONSTTIME);
-        } else
-                pr1 = r1;
-        if (!BN_mod(r0, pr1, rsa->p, ctx))
+        BN_with_flags(&pr1, r1, BN_FLG_CONSTTIME);
+
+        if (!BN_mod(r0, &pr1, rsa->p, ctx))
                 goto err;
 
         /*
@@ -875,18 +845,14 @@ RSA_eay_mod_exp(BIGNUM *r0, const BIGNUM *I, RSA *rsa, BN_CTX *ctx)
                          * miscalculated CRT output, just do a raw (slower)
                          * mod_exp and return that instead.
                          */
+                        BIGNUM d;
 
-                        BIGNUM local_d;
-                        BIGNUM *d = NULL;
+                        BN_with_flags(&d, rsa->d, BN_FLG_CONSTTIME);
 
-                        if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME)) {
-                                d = &local_d;
-                                BN_with_flags(d, rsa->d, BN_FLG_CONSTTIME);
-                        } else
-                                d = rsa->d;
-                        if (!rsa->meth->bn_mod_exp(r0, I, d, rsa->n, ctx,
-                            rsa->_method_mod_n))
+                        if (!rsa->meth->bn_mod_exp(r0, I, &d, rsa->n, ctx,
+                            rsa->_method_mod_n)) {
                                 goto err;
+                        }
                 }
         }
         ret = 1;
diff --git a/src/lib/libssl/src/crypto/rsa/rsa_gen.c b/src/lib/libssl/src/crypto/rsa/rsa_gen.c
index f6f051c442..d46f4f2478 100644
--- a/src/lib/libssl/src/crypto/rsa/rsa_gen.c
+++ b/src/lib/libssl/src/crypto/rsa/rsa_gen.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: rsa_gen.c,v 1.17 2015/02/09 15:49:22 jsing Exp $ */
+/* $OpenBSD: rsa_gen.c,v 1.18 2016/06/30 02:02:06 bcook Exp $ */
 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
  * All rights reserved.
  *
@@ -90,8 +90,7 @@ static int
 rsa_builtin_keygen(RSA *rsa, int bits, BIGNUM *e_value, BN_GENCB *cb)
 {
         BIGNUM *r0 = NULL, *r1 = NULL, *r2 = NULL, *r3 = NULL, *tmp;
-        BIGNUM local_r0, local_d, local_p;
-        BIGNUM *pr0, *d, *p;
+        BIGNUM pr0, d, p;
         int bitsp, bitsq, ok = -1, n = 0;
         BN_CTX *ctx = NULL;
 
@@ -193,36 +192,26 @@ rsa_builtin_keygen(RSA *rsa, int bits, BIGNUM *e_value, BN_GENCB *cb)
                 goto err;
         if (!BN_mul(r0, r1, r2, ctx))                   /* (p-1)(q-1) */
                 goto err;
-        if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME)) {
-                pr0 = &local_r0;
-                BN_with_flags(pr0, r0, BN_FLG_CONSTTIME);
-        } else
-                pr0 = r0;
-        if (!BN_mod_inverse(rsa->d, rsa->e, pr0, ctx))  /* d */
+
+        BN_with_flags(&pr0, r0, BN_FLG_CONSTTIME);
+
+        if (!BN_mod_inverse(rsa->d, rsa->e, &pr0, ctx)) /* d */
                 goto err;
 
         /* set up d for correct BN_FLG_CONSTTIME flag */
-        if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME)) {
-                d = &local_d;
-                BN_with_flags(d, rsa->d, BN_FLG_CONSTTIME);
-        } else
-                d = rsa->d;
+        BN_with_flags(&d, rsa->d, BN_FLG_CONSTTIME);
 
         /* calculate d mod (p-1) */
-        if (!BN_mod(rsa->dmp1, d, r1, ctx))
+        if (!BN_mod(rsa->dmp1, &d, r1, ctx))
                 goto err;
 
         /* calculate d mod (q-1) */
-        if (!BN_mod(rsa->dmq1, d, r2, ctx))
+        if (!BN_mod(rsa->dmq1, &d, r2, ctx))
                 goto err;
 
         /* calculate inverse of q mod p */
-        if (!(rsa->flags & RSA_FLAG_NO_CONSTTIME)) {
-                p = &local_p;
-                BN_with_flags(p, rsa->p, BN_FLG_CONSTTIME);
-        } else
-                p = rsa->p;
-        if (!BN_mod_inverse(rsa->iqmp, rsa->q, p, ctx))
+        BN_with_flags(&p, rsa->p, BN_FLG_CONSTTIME);
+        if (!BN_mod_inverse(rsa->iqmp, rsa->q, &p, ctx))
                 goto err;
 
         ok = 1;