Merged origin/release (checked in because wanted to merge new stuff)

1 files changed, 1237 insertions, 941 deletions

diff --git a/openssl/crypto/bn/bn_exp.c b/openssl/crypto/bn/bn_exp.c
index 611fa3262..28a9fd53b 100644
--- a/openssl/crypto/bn/bn_exp.c
+++ b/openssl/crypto/bn/bn_exp.c
@@ -5,21 +5,21 @@
  * This package is an SSL implementation written
  * by Eric Young (eay@cryptsoft.com).
  * The implementation was written so as to conform with Netscapes SSL.
- * 
+ *
  * This library is free for commercial and non-commercial use as long as
  * the following conditions are aheared to.  The following conditions
  * apply to all code found in this distribution, be it the RC4, RSA,
  * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
  * included with this distribution is covered by the same copyright terms
  * except that the holder is Tim Hudson (tjh@cryptsoft.com).
- * 
+ *
  * Copyright remains Eric Young's, and as such any Copyright notices in
  * the code are not to be removed.
  * If this package is used in a product, Eric Young should be given attribution
  * as the author of the parts of the library used.
  * This can be in the form of a textual message at program startup or
  * in documentation (online or textual) provided with the package.
- * 
+ *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
@@ -34,10 +34,10 @@
  *     Eric Young (eay@cryptsoft.com)"
  *    The word 'cryptographic' can be left out if the rouines from the library
  *    being used are not cryptographic related :-).
- * 4. If you include any Windows specific code (or a derivative thereof) from 
+ * 4. If you include any Windows specific code (or a derivative thereof) from
  *    the apps directory (application code) you must include an acknowledgement:
  *    "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
- * 
+ *
  * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
@@ -49,7 +49,7 @@
  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  * SUCH DAMAGE.
- * 
+ *
  * The licence and distribution terms for any publically available version or
  * derivative of this code cannot be changed.  i.e. this code cannot simply be
  * copied and put under another distribution licence
@@ -63,7 +63,7 @@
  * are met:
  *
  * 1. Redistributions of source code must retain the above copyright
- *    notice, this list of conditions and the following disclaimer. 
+ *    notice, this list of conditions and the following disclaimer.
  *
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in
@@ -109,7 +109,6 @@
  *
  */
 
-
 #include "cryptlib.h"
 #include "bn_lcl.h"
 
@@ -123,982 +122,1279 @@
 # ifndef alloca
 #  define alloca(s) __builtin_alloca((s))
 # endif
+#elif defined(__sun)
+# include <alloca.h>
+#endif
+
+#undef RSAZ_ENABLED
+#if defined(OPENSSL_BN_ASM_MONT) && \
+        (defined(__x86_64) || defined(__x86_64__) || \
+         defined(_M_AMD64) || defined(_M_X64))
+# include "rsaz_exp.h"
+# define RSAZ_ENABLED
+#endif
+
+#undef SPARC_T4_MONT
+#if defined(OPENSSL_BN_ASM_MONT) && (defined(__sparc__) || defined(__sparc))
+# include "sparc_arch.h"
+extern unsigned int OPENSSL_sparcv9cap_P[];
+# define SPARC_T4_MONT
 #endif
 
 /* maximum precomputation table size for *variable* sliding windows */
-#define TABLE_SIZE	32
+#define TABLE_SIZE      32
 
 /* this one works - simple but works */
 int BN_exp(BIGNUM *r, const BIGNUM *a, const BIGNUM *p, BN_CTX *ctx)
-	{
-	int i,bits,ret=0;
-	BIGNUM *v,*rr;
-
-	if (BN_get_flags(p, BN_FLG_CONSTTIME) != 0)
-		{
-		/* BN_FLG_CONSTTIME only supported by BN_mod_exp_mont() */
-		BNerr(BN_F_BN_EXP,ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
-		return -1;
-		}
-
-	BN_CTX_start(ctx);
-	if ((r == a) || (r == p))
-		rr = BN_CTX_get(ctx);
-	else
-		rr = r;
-	v = BN_CTX_get(ctx);
-	if (rr == NULL || v == NULL) goto err;
-
-	if (BN_copy(v,a) == NULL) goto err;
-	bits=BN_num_bits(p);
-
-	if (BN_is_odd(p))
-		{ if (BN_copy(rr,a) == NULL) goto err; }
-	else	{ if (!BN_one(rr)) goto err; }
-
-	for (i=1; i<bits; i++)
-		{
-		if (!BN_sqr(v,v,ctx)) goto err;
-		if (BN_is_bit_set(p,i))
-			{
-			if (!BN_mul(rr,rr,v,ctx)) goto err;
-			}
-		}
-	ret=1;
-err:
-	if (r != rr) BN_copy(r,rr);
-	BN_CTX_end(ctx);
-	bn_check_top(r);
-	return(ret);
-	}
-
+{
+    int i, bits, ret = 0;
+    BIGNUM *v, *rr;
+
+    if (BN_get_flags(p, BN_FLG_CONSTTIME) != 0) {
+        /* BN_FLG_CONSTTIME only supported by BN_mod_exp_mont() */
+        BNerr(BN_F_BN_EXP, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
+        return -1;
+    }
+
+    BN_CTX_start(ctx);
+    if ((r == a) || (r == p))
+        rr = BN_CTX_get(ctx);
+    else
+        rr = r;
+    v = BN_CTX_get(ctx);
+    if (rr == NULL || v == NULL)
+        goto err;
+
+    if (BN_copy(v, a) == NULL)
+        goto err;
+    bits = BN_num_bits(p);
+
+    if (BN_is_odd(p)) {
+        if (BN_copy(rr, a) == NULL)
+            goto err;
+    } else {
+        if (!BN_one(rr))
+            goto err;
+    }
+
+    for (i = 1; i < bits; i++) {
+        if (!BN_sqr(v, v, ctx))
+            goto err;
+        if (BN_is_bit_set(p, i)) {
+            if (!BN_mul(rr, rr, v, ctx))
+                goto err;
+        }
+    }
+    ret = 1;
+ err:
+    if (r != rr)
+        BN_copy(r, rr);
+    BN_CTX_end(ctx);
+    bn_check_top(r);
+    return (ret);
+}
 
 int BN_mod_exp(BIGNUM *r, const BIGNUM *a, const BIGNUM *p, const BIGNUM *m,
-	       BN_CTX *ctx)
-	{
-	int ret;
-
-	bn_check_top(a);
-	bn_check_top(p);
-	bn_check_top(m);
-
-	/* For even modulus  m = 2^k*m_odd,  it might make sense to compute
-	 * a^p mod m_odd  and  a^p mod 2^k  separately (with Montgomery
-	 * exponentiation for the odd part), using appropriate exponent
-	 * reductions, and combine the results using the CRT.
-	 *
-	 * For now, we use Montgomery only if the modulus is odd; otherwise,
-	 * exponentiation using the reciprocal-based quick remaindering
-	 * algorithm is used.
-	 *
-	 * (Timing obtained with expspeed.c [computations  a^p mod m
-	 * where  a, p, m  are of the same length: 256, 512, 1024, 2048,
-	 * 4096, 8192 bits], compared to the running time of the
-	 * standard algorithm:
-	 *
-	 *   BN_mod_exp_mont   33 .. 40 %  [AMD K6-2, Linux, debug configuration]
-         *                     55 .. 77 %  [UltraSparc processor, but
-	 *                                  debug-solaris-sparcv8-gcc conf.]
-	 * 
-	 *   BN_mod_exp_recp   50 .. 70 %  [AMD K6-2, Linux, debug configuration]
-	 *                     62 .. 118 % [UltraSparc, debug-solaris-sparcv8-gcc]
-	 *
-	 * On the Sparc, BN_mod_exp_recp was faster than BN_mod_exp_mont
-	 * at 2048 and more bits, but at 512 and 1024 bits, it was
-	 * slower even than the standard algorithm!
-	 *
-	 * "Real" timings [linux-elf, solaris-sparcv9-gcc configurations]
-	 * should be obtained when the new Montgomery reduction code
-	 * has been integrated into OpenSSL.)
-	 */
+               BN_CTX *ctx)
+{
+    int ret;
+
+    bn_check_top(a);
+    bn_check_top(p);
+    bn_check_top(m);
+
+    /*-
+     * For even modulus  m = 2^k*m_odd,  it might make sense to compute
+     * a^p mod m_odd  and  a^p mod 2^k  separately (with Montgomery
+     * exponentiation for the odd part), using appropriate exponent
+     * reductions, and combine the results using the CRT.
+     *
+     * For now, we use Montgomery only if the modulus is odd; otherwise,
+     * exponentiation using the reciprocal-based quick remaindering
+     * algorithm is used.
+     *
+     * (Timing obtained with expspeed.c [computations  a^p mod m
+     * where  a, p, m  are of the same length: 256, 512, 1024, 2048,
+     * 4096, 8192 bits], compared to the running time of the
+     * standard algorithm:
+     *
+     *   BN_mod_exp_mont   33 .. 40 %  [AMD K6-2, Linux, debug configuration]
+     *                     55 .. 77 %  [UltraSparc processor, but
+     *                                  debug-solaris-sparcv8-gcc conf.]
+     *
+     *   BN_mod_exp_recp   50 .. 70 %  [AMD K6-2, Linux, debug configuration]
+     *                     62 .. 118 % [UltraSparc, debug-solaris-sparcv8-gcc]
+     *
+     * On the Sparc, BN_mod_exp_recp was faster than BN_mod_exp_mont
+     * at 2048 and more bits, but at 512 and 1024 bits, it was
+     * slower even than the standard algorithm!
+     *
+     * "Real" timings [linux-elf, solaris-sparcv9-gcc configurations]
+     * should be obtained when the new Montgomery reduction code
+     * has been integrated into OpenSSL.)
+     */
 
 #define MONT_MUL_MOD
 #define MONT_EXP_WORD
 #define RECP_MUL_MOD
 
 #ifdef MONT_MUL_MOD
-	/* I have finally been able to take out this pre-condition of
-	 * the top bit being set.  It was caused by an error in BN_div
-	 * with negatives.  There was also another problem when for a^b%m
-	 * a >= m.  eay 07-May-97 */
-/*	if ((m->d[m->top-1]&BN_TBIT) && BN_is_odd(m)) */
-
-	if (BN_is_odd(m))
-		{
-#  ifdef MONT_EXP_WORD
-		if (a->top == 1 && !a->neg && (BN_get_flags(p, BN_FLG_CONSTTIME) == 0))
-			{
-			BN_ULONG A = a->d[0];
-			ret=BN_mod_exp_mont_word(r,A,p,m,ctx,NULL);
-			}
-		else
-#  endif
-			ret=BN_mod_exp_mont(r,a,p,m,ctx,NULL);
-		}
-	else
+    /*
+     * I have finally been able to take out this pre-condition of the top bit
+     * being set.  It was caused by an error in BN_div with negatives.  There
+     * was also another problem when for a^b%m a >= m.  eay 07-May-97
+     */
+    /* if ((m->d[m->top-1]&BN_TBIT) && BN_is_odd(m)) */
+
+    if (BN_is_odd(m)) {
+# ifdef MONT_EXP_WORD
+        if (a->top == 1 && !a->neg
+            && (BN_get_flags(p, BN_FLG_CONSTTIME) == 0)) {
+            BN_ULONG A = a->d[0];
+            ret = BN_mod_exp_mont_word(r, A, p, m, ctx, NULL);
+        } else
+# endif
+            ret = BN_mod_exp_mont(r, a, p, m, ctx, NULL);
+    } else
 #endif
 #ifdef RECP_MUL_MOD
-		{ ret=BN_mod_exp_recp(r,a,p,m,ctx); }
+    {
+        ret = BN_mod_exp_recp(r, a, p, m, ctx);
+    }
 #else
-		{ ret=BN_mod_exp_simple(r,a,p,m,ctx); }
+    {
+        ret = BN_mod_exp_simple(r, a, p, m, ctx);
+    }
 #endif
 
-	bn_check_top(r);
-	return(ret);
-	}
-
+    bn_check_top(r);
+    return (ret);
+}
 
 int BN_mod_exp_recp(BIGNUM *r, const BIGNUM *a, const BIGNUM *p,
-		    const BIGNUM *m, BN_CTX *ctx)
-	{
-	int i,j,bits,ret=0,wstart,wend,window,wvalue;
-	int start=1;
-	BIGNUM *aa;
-	/* Table of variables obtained from 'ctx' */
-	BIGNUM *val[TABLE_SIZE];
-	BN_RECP_CTX recp;
-
-	if (BN_get_flags(p, BN_FLG_CONSTTIME) != 0)
-		{
-		/* BN_FLG_CONSTTIME only supported by BN_mod_exp_mont() */
-		BNerr(BN_F_BN_MOD_EXP_RECP,ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
-		return -1;
-		}
-
-	bits=BN_num_bits(p);
-
-	if (bits == 0)
-		{
-		ret = BN_one(r);
-		return ret;
-		}
-
-	BN_CTX_start(ctx);
-	aa = BN_CTX_get(ctx);
-	val[0] = BN_CTX_get(ctx);
-	if(!aa || !val[0]) goto err;
-
-	BN_RECP_CTX_init(&recp);
-	if (m->neg)
-		{
-		/* ignore sign of 'm' */
-		if (!BN_copy(aa, m)) goto err;
-		aa->neg = 0;
-		if (BN_RECP_CTX_set(&recp,aa,ctx) <= 0) goto err;
-		}
-	else
-		{
-		if (BN_RECP_CTX_set(&recp,m,ctx) <= 0) goto err;
-		}
-
-	if (!BN_nnmod(val[0],a,m,ctx)) goto err;		/* 1 */
-	if (BN_is_zero(val[0]))
-		{
-		BN_zero(r);
-		ret = 1;
-		goto err;
-		}
-
-	window = BN_window_bits_for_exponent_size(bits);
-	if (window > 1)
-		{
-		if (!BN_mod_mul_reciprocal(aa,val[0],val[0],&recp,ctx))
-			goto err;				/* 2 */
-		j=1<<(window-1);
-		for (i=1; i<j; i++)
-			{
-			if(((val[i] = BN_CTX_get(ctx)) == NULL) ||
-					!BN_mod_mul_reciprocal(val[i],val[i-1],
-						aa,&recp,ctx))
-				goto err;
-			}
-		}
-		
-	start=1;	/* This is used to avoid multiplication etc
-			 * when there is only the value '1' in the
-			 * buffer. */
-	wvalue=0;	/* The 'value' of the window */
-	wstart=bits-1;	/* The top bit of the window */
-	wend=0;		/* The bottom bit of the window */
-
-	if (!BN_one(r)) goto err;
-
-	for (;;)
-		{
-		if (BN_is_bit_set(p,wstart) == 0)
-			{
-			if (!start)
-				if (!BN_mod_mul_reciprocal(r,r,r,&recp,ctx))
-				goto err;
-			if (wstart == 0) break;
-			wstart--;
-			continue;
-			}
-		/* We now have wstart on a 'set' bit, we now need to work out
-		 * how bit a window to do.  To do this we need to scan
-		 * forward until the last set bit before the end of the
-		 * window */
-		j=wstart;
-		wvalue=1;
-		wend=0;
-		for (i=1; i<window; i++)
-			{
-			if (wstart-i < 0) break;
-			if (BN_is_bit_set(p,wstart-i))
-				{
-				wvalue<<=(i-wend);
-				wvalue|=1;
-				wend=i;
-				}
-			}
-
-		/* wend is the size of the current window */
-		j=wend+1;
-		/* add the 'bytes above' */
-		if (!start)
-			for (i=0; i<j; i++)
-				{
-				if (!BN_mod_mul_reciprocal(r,r,r,&recp,ctx))
-					goto err;
-				}
-		
-		/* wvalue will be an odd number < 2^window */
-		if (!BN_mod_mul_reciprocal(r,r,val[wvalue>>1],&recp,ctx))
-			goto err;
-
-		/* move the 'window' down further */
-		wstart-=wend+1;
-		wvalue=0;
-		start=0;
-		if (wstart < 0) break;
-		}
-	ret=1;
-err:
-	BN_CTX_end(ctx);
-	BN_RECP_CTX_free(&recp);
-	bn_check_top(r);
-	return(ret);
-	}
-
+                    const BIGNUM *m, BN_CTX *ctx)
+{
+    int i, j, bits, ret = 0, wstart, wend, window, wvalue;
+    int start = 1;
+    BIGNUM *aa;
+    /* Table of variables obtained from 'ctx' */
+    BIGNUM *val[TABLE_SIZE];
+    BN_RECP_CTX recp;
+
+    if (BN_get_flags(p, BN_FLG_CONSTTIME) != 0) {
+        /* BN_FLG_CONSTTIME only supported by BN_mod_exp_mont() */
+        BNerr(BN_F_BN_MOD_EXP_RECP, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
+        return -1;
+    }
+
+    bits = BN_num_bits(p);
+
+    if (bits == 0) {
+        ret = BN_one(r);
+        return ret;
+    }
+
+    BN_CTX_start(ctx);
+    aa = BN_CTX_get(ctx);
+    val[0] = BN_CTX_get(ctx);
+    if (!aa || !val[0])
+        goto err;
+
+    BN_RECP_CTX_init(&recp);
+    if (m->neg) {
+        /* ignore sign of 'm' */
+        if (!BN_copy(aa, m))
+            goto err;
+        aa->neg = 0;
+        if (BN_RECP_CTX_set(&recp, aa, ctx) <= 0)
+            goto err;
+    } else {
+        if (BN_RECP_CTX_set(&recp, m, ctx) <= 0)
+            goto err;
+    }
+
+    if (!BN_nnmod(val[0], a, m, ctx))
+        goto err;               /* 1 */
+    if (BN_is_zero(val[0])) {
+        BN_zero(r);
+        ret = 1;
+        goto err;
+    }
+
+    window = BN_window_bits_for_exponent_size(bits);
+    if (window > 1) {
+        if (!BN_mod_mul_reciprocal(aa, val[0], val[0], &recp, ctx))
+            goto err;           /* 2 */
+        j = 1 << (window - 1);
+        for (i = 1; i < j; i++) {
+            if (((val[i] = BN_CTX_get(ctx)) == NULL) ||
+                !BN_mod_mul_reciprocal(val[i], val[i - 1], aa, &recp, ctx))
+                goto err;
+        }
+    }
+
+    start = 1;                  /* This is used to avoid multiplication etc
+                                 * when there is only the value '1' in the
+                                 * buffer. */
+    wvalue = 0;                 /* The 'value' of the window */
+    wstart = bits - 1;          /* The top bit of the window */
+    wend = 0;                   /* The bottom bit of the window */
+
+    if (!BN_one(r))
+        goto err;
+
+    for (;;) {
+        if (BN_is_bit_set(p, wstart) == 0) {
+            if (!start)
+                if (!BN_mod_mul_reciprocal(r, r, r, &recp, ctx))
+                    goto err;
+            if (wstart == 0)
+                break;
+            wstart--;
+            continue;
+        }
+        /*
+         * We now have wstart on a 'set' bit, we now need to work out how bit
+         * a window to do.  To do this we need to scan forward until the last
+         * set bit before the end of the window
+         */
+        j = wstart;
+        wvalue = 1;
+        wend = 0;
+        for (i = 1; i < window; i++) {
+            if (wstart - i < 0)
+                break;
+            if (BN_is_bit_set(p, wstart - i)) {
+                wvalue <<= (i - wend);
+                wvalue |= 1;
+                wend = i;
+            }
+        }
+
+        /* wend is the size of the current window */
+        j = wend + 1;
+        /* add the 'bytes above' */
+        if (!start)
+            for (i = 0; i < j; i++) {
+                if (!BN_mod_mul_reciprocal(r, r, r, &recp, ctx))
+                    goto err;
+            }
+
+        /* wvalue will be an odd number < 2^window */
+        if (!BN_mod_mul_reciprocal(r, r, val[wvalue >> 1], &recp, ctx))
+            goto err;
+
+        /* move the 'window' down further */
+        wstart -= wend + 1;
+        wvalue = 0;
+        start = 0;
+        if (wstart < 0)
+            break;
+    }
+    ret = 1;
+ err:
+    BN_CTX_end(ctx);
+    BN_RECP_CTX_free(&recp);
+    bn_check_top(r);
+    return (ret);
+}
 
 int BN_mod_exp_mont(BIGNUM *rr, const BIGNUM *a, const BIGNUM *p,
-		    const BIGNUM *m, BN_CTX *ctx, BN_MONT_CTX *in_mont)
-	{
-	int i,j,bits,ret=0,wstart,wend,window,wvalue;
-	int start=1;
-	BIGNUM *d,*r;
-	const BIGNUM *aa;
-	/* Table of variables obtained from 'ctx' */
-	BIGNUM *val[TABLE_SIZE];
-	BN_MONT_CTX *mont=NULL;
-
-	if (BN_get_flags(p, BN_FLG_CONSTTIME) != 0)
-		{
-		return BN_mod_exp_mont_consttime(rr, a, p, m, ctx, in_mont);
-		}
-
-	bn_check_top(a);
-	bn_check_top(p);
-	bn_check_top(m);
-
-	if (!BN_is_odd(m))
-		{
-		BNerr(BN_F_BN_MOD_EXP_MONT,BN_R_CALLED_WITH_EVEN_MODULUS);
-		return(0);
-		}
-	bits=BN_num_bits(p);
-	if (bits == 0)
-		{
-		ret = BN_one(rr);
-		return ret;
-		}
-
-	BN_CTX_start(ctx);
-	d = BN_CTX_get(ctx);
-	r = BN_CTX_get(ctx);
-	val[0] = BN_CTX_get(ctx);
-	if (!d || !r || !val[0]) goto err;
-
-	/* If this is not done, things will break in the montgomery
-	 * part */
-
-	if (in_mont != NULL)
-		mont=in_mont;
-	else
-		{
-		if ((mont=BN_MONT_CTX_new()) == NULL) goto err;
-		if (!BN_MONT_CTX_set(mont,m,ctx)) goto err;
-		}
-
-	if (a->neg || BN_ucmp(a,m) >= 0)
-		{
-		if (!BN_nnmod(val[0],a,m,ctx))
-			goto err;
-		aa= val[0];
-		}
-	else
-		aa=a;
-	if (BN_is_zero(aa))
-		{
-		BN_zero(rr);
-		ret = 1;
-		goto err;
-		}
-	if (!BN_to_montgomery(val[0],aa,mont,ctx)) goto err; /* 1 */
-
-	window = BN_window_bits_for_exponent_size(bits);
-	if (window > 1)
-		{
-		if (!BN_mod_mul_montgomery(d,val[0],val[0],mont,ctx)) goto err; /* 2 */
-		j=1<<(window-1);
-		for (i=1; i<j; i++)
-			{
-			if(((val[i] = BN_CTX_get(ctx)) == NULL) ||
-					!BN_mod_mul_montgomery(val[i],val[i-1],
-						d,mont,ctx))
-				goto err;
-			}
-		}
-
-	start=1;	/* This is used to avoid multiplication etc
-			 * when there is only the value '1' in the
-			 * buffer. */
-	wvalue=0;	/* The 'value' of the window */
-	wstart=bits-1;	/* The top bit of the window */
-	wend=0;		/* The bottom bit of the window */
-
-	if (!BN_to_montgomery(r,BN_value_one(),mont,ctx)) goto err;
-	for (;;)
-		{
-		if (BN_is_bit_set(p,wstart) == 0)
-			{
-			if (!start)
-				{
-				if (!BN_mod_mul_montgomery(r,r,r,mont,ctx))
-				goto err;
-				}
-			if (wstart == 0) break;
-			wstart--;
-			continue;
-			}
-		/* We now have wstart on a 'set' bit, we now need to work out
-		 * how bit a window to do.  To do this we need to scan
-		 * forward until the last set bit before the end of the
-		 * window */
-		j=wstart;
-		wvalue=1;
-		wend=0;
-		for (i=1; i<window; i++)
-			{
-			if (wstart-i < 0) break;
-			if (BN_is_bit_set(p,wstart-i))
-				{
-				wvalue<<=(i-wend);
-				wvalue|=1;
-				wend=i;
-				}
-			}
-
-		/* wend is the size of the current window */
-		j=wend+1;
-		/* add the 'bytes above' */
-		if (!start)
-			for (i=0; i<j; i++)
-				{
-				if (!BN_mod_mul_montgomery(r,r,r,mont,ctx))
-					goto err;
-				}
-		
-		/* wvalue will be an odd number < 2^window */
-		if (!BN_mod_mul_montgomery(r,r,val[wvalue>>1],mont,ctx))
-			goto err;
-
-		/* move the 'window' down further */
-		wstart-=wend+1;
-		wvalue=0;
-		start=0;
-		if (wstart < 0) break;
-		}
-	if (!BN_from_montgomery(rr,r,mont,ctx)) goto err;
-	ret=1;
-err:
-	if ((in_mont == NULL) && (mont != NULL)) BN_MONT_CTX_free(mont);
-	BN_CTX_end(ctx);
-	bn_check_top(rr);
-	return(ret);
-	}
-
-
-/* BN_mod_exp_mont_consttime() stores the precomputed powers in a specific layout
- * so that accessing any of these table values shows the same access pattern as far
- * as cache lines are concerned.  The following functions are used to transfer a BIGNUM
- * from/to that table. */
-
-static int MOD_EXP_CTIME_COPY_TO_PREBUF(const BIGNUM *b, int top, unsigned char *buf, int idx, int width)
-	{
-	size_t i, j;
-
-	if (top > b->top)
-		top = b->top; /* this works because 'buf' is explicitly zeroed */
-	for (i = 0, j=idx; i < top * sizeof b->d[0]; i++, j+=width)
-		{
-		buf[j] = ((unsigned char*)b->d)[i];
-		}
-
-	return 1;
-	}
-
-static int MOD_EXP_CTIME_COPY_FROM_PREBUF(BIGNUM *b, int top, unsigned char *buf, int idx, int width)
-	{
-	size_t i, j;
-
-	if (bn_wexpand(b, top) == NULL)
-		return 0;
-
-	for (i=0, j=idx; i < top * sizeof b->d[0]; i++, j+=width)
-		{
-		((unsigned char*)b->d)[i] = buf[j];
-		}
-
-	b->top = top;
-	bn_correct_top(b);
-	return 1;
-	}	
-
-/* Given a pointer value, compute the next address that is a cache line multiple. */
-#define MOD_EXP_CTIME_ALIGN(x_) \
-	((unsigned char*)(x_) + (MOD_EXP_CTIME_MIN_CACHE_LINE_WIDTH - (((size_t)(x_)) & (MOD_EXP_CTIME_MIN_CACHE_LINE_MASK))))
+                    const BIGNUM *m, BN_CTX *ctx, BN_MONT_CTX *in_mont)
+{
+    int i, j, bits, ret = 0, wstart, wend, window, wvalue;
+    int start = 1;
+    BIGNUM *d, *r;
+    const BIGNUM *aa;
+    /* Table of variables obtained from 'ctx' */
+    BIGNUM *val[TABLE_SIZE];
+    BN_MONT_CTX *mont = NULL;
+
+    if (BN_get_flags(p, BN_FLG_CONSTTIME) != 0) {
+        return BN_mod_exp_mont_consttime(rr, a, p, m, ctx, in_mont);
+    }
+
+    bn_check_top(a);
+    bn_check_top(p);
+    bn_check_top(m);
+
+    if (!BN_is_odd(m)) {
+        BNerr(BN_F_BN_MOD_EXP_MONT, BN_R_CALLED_WITH_EVEN_MODULUS);
+        return (0);
+    }
+    bits = BN_num_bits(p);
+    if (bits == 0) {
+        ret = BN_one(rr);
+        return ret;
+    }
+
+    BN_CTX_start(ctx);
+    d = BN_CTX_get(ctx);
+    r = BN_CTX_get(ctx);
+    val[0] = BN_CTX_get(ctx);
+    if (!d || !r || !val[0])
+        goto err;
+
+    /*
+     * If this is not done, things will break in the montgomery part
+     */
+
+    if (in_mont != NULL)
+        mont = in_mont;
+    else {
+        if ((mont = BN_MONT_CTX_new()) == NULL)
+            goto err;
+        if (!BN_MONT_CTX_set(mont, m, ctx))
+            goto err;
+    }
+
+    if (a->neg || BN_ucmp(a, m) >= 0) {
+        if (!BN_nnmod(val[0], a, m, ctx))
+            goto err;
+        aa = val[0];
+    } else
+        aa = a;
+    if (BN_is_zero(aa)) {
+        BN_zero(rr);
+        ret = 1;
+        goto err;
+    }
+    if (!BN_to_montgomery(val[0], aa, mont, ctx))
+        goto err;               /* 1 */
+
+    window = BN_window_bits_for_exponent_size(bits);
+    if (window > 1) {
+        if (!BN_mod_mul_montgomery(d, val[0], val[0], mont, ctx))
+            goto err;           /* 2 */
+        j = 1 << (window - 1);
+        for (i = 1; i < j; i++) {
+            if (((val[i] = BN_CTX_get(ctx)) == NULL) ||
+                !BN_mod_mul_montgomery(val[i], val[i - 1], d, mont, ctx))
+                goto err;
+        }
+    }
+
+    start = 1;                  /* This is used to avoid multiplication etc
+                                 * when there is only the value '1' in the
+                                 * buffer. */
+    wvalue = 0;                 /* The 'value' of the window */
+    wstart = bits - 1;          /* The top bit of the window */
+    wend = 0;                   /* The bottom bit of the window */
+
+#if 1                           /* by Shay Gueron's suggestion */
+    j = m->top;                 /* borrow j */
+    if (m->d[j - 1] & (((BN_ULONG)1) << (BN_BITS2 - 1))) {
+        if (bn_wexpand(r, j) == NULL)
+            goto err;
+        /* 2^(top*BN_BITS2) - m */
+        r->d[0] = (0 - m->d[0]) & BN_MASK2;
+        for (i = 1; i < j; i++)
+            r->d[i] = (~m->d[i]) & BN_MASK2;
+        r->top = j;
+        /*
+         * Upper words will be zero if the corresponding words of 'm' were
+         * 0xfff[...], so decrement r->top accordingly.
+         */
+        bn_correct_top(r);
+    } else
+#endif
+    if (!BN_to_montgomery(r, BN_value_one(), mont, ctx))
+        goto err;
+    for (;;) {
+        if (BN_is_bit_set(p, wstart) == 0) {
+            if (!start) {
+                if (!BN_mod_mul_montgomery(r, r, r, mont, ctx))
+                    goto err;
+            }
+            if (wstart == 0)
+                break;
+            wstart--;
+            continue;
+        }
+        /*
+         * We now have wstart on a 'set' bit, we now need to work out how bit
+         * a window to do.  To do this we need to scan forward until the last
+         * set bit before the end of the window
+         */
+        j = wstart;
+        wvalue = 1;
+        wend = 0;
+        for (i = 1; i < window; i++) {
+            if (wstart - i < 0)
+                break;
+            if (BN_is_bit_set(p, wstart - i)) {
+                wvalue <<= (i - wend);
+                wvalue |= 1;
+                wend = i;
+            }
+        }
+
+        /* wend is the size of the current window */
+        j = wend + 1;
+        /* add the 'bytes above' */
+        if (!start)
+            for (i = 0; i < j; i++) {
+                if (!BN_mod_mul_montgomery(r, r, r, mont, ctx))
+                    goto err;
+            }
+
+        /* wvalue will be an odd number < 2^window */
+        if (!BN_mod_mul_montgomery(r, r, val[wvalue >> 1], mont, ctx))
+            goto err;
+
+        /* move the 'window' down further */
+        wstart -= wend + 1;
+        wvalue = 0;
+        start = 0;
+        if (wstart < 0)
+            break;
+    }
+#if defined(SPARC_T4_MONT)
+    if (OPENSSL_sparcv9cap_P[0] & (SPARCV9_VIS3 | SPARCV9_PREFER_FPU)) {
+        j = mont->N.top;        /* borrow j */
+        val[0]->d[0] = 1;       /* borrow val[0] */
+        for (i = 1; i < j; i++)
+            val[0]->d[i] = 0;
+        val[0]->top = j;
+        if (!BN_mod_mul_montgomery(rr, r, val[0], mont, ctx))
+            goto err;
+    } else
+#endif
+    if (!BN_from_montgomery(rr, r, mont, ctx))
+        goto err;
+    ret = 1;
+ err:
+    if ((in_mont == NULL) && (mont != NULL))
+        BN_MONT_CTX_free(mont);
+    BN_CTX_end(ctx);
+    bn_check_top(rr);
+    return (ret);
+}
+
+#if defined(SPARC_T4_MONT)
+static BN_ULONG bn_get_bits(const BIGNUM *a, int bitpos)
+{
+    BN_ULONG ret = 0;
+    int wordpos;
+
+    wordpos = bitpos / BN_BITS2;
+    bitpos %= BN_BITS2;
+    if (wordpos >= 0 && wordpos < a->top) {
+        ret = a->d[wordpos] & BN_MASK2;
+        if (bitpos) {
+            ret >>= bitpos;
+            if (++wordpos < a->top)
+                ret |= a->d[wordpos] << (BN_BITS2 - bitpos);
+        }
+    }
+
+    return ret & BN_MASK2;
+}
+#endif
 
-/* This variant of BN_mod_exp_mont() uses fixed windows and the special
- * precomputation memory layout to limit data-dependency to a minimum
- * to protect secret exponents (cf. the hyper-threading timing attacks
- * pointed out by Colin Percival,
- * http://www.daemonology.net/hyperthreading-considered-harmful/)
+/*
+ * BN_mod_exp_mont_consttime() stores the precomputed powers in a specific
+ * layout so that accessing any of these table values shows the same access
+ * pattern as far as cache lines are concerned.  The following functions are
+ * used to transfer a BIGNUM from/to that table.
+ */
+
+static int MOD_EXP_CTIME_COPY_TO_PREBUF(const BIGNUM *b, int top,
+                                        unsigned char *buf, int idx,
+                                        int width)
+{
+    size_t i, j;
+
+    if (top > b->top)
+        top = b->top;           /* this works because 'buf' is explicitly
+                                 * zeroed */
+    for (i = 0, j = idx; i < top * sizeof b->d[0]; i++, j += width) {
+        buf[j] = ((unsigned char *)b->d)[i];
+    }
+
+    return 1;
+}
+
+static int MOD_EXP_CTIME_COPY_FROM_PREBUF(BIGNUM *b, int top,
+                                          unsigned char *buf, int idx,
+                                          int width)
+{
+    size_t i, j;
+
+    if (bn_wexpand(b, top) == NULL)
+        return 0;
+
+    for (i = 0, j = idx; i < top * sizeof b->d[0]; i++, j += width) {
+        ((unsigned char *)b->d)[i] = buf[j];
+    }
+
+    b->top = top;
+    bn_correct_top(b);
+    return 1;
+}
+
+/*
+ * Given a pointer value, compute the next address that is a cache line
+ * multiple.
+ */
+#define MOD_EXP_CTIME_ALIGN(x_) \
+        ((unsigned char*)(x_) + (MOD_EXP_CTIME_MIN_CACHE_LINE_WIDTH - (((size_t)(x_)) & (MOD_EXP_CTIME_MIN_CACHE_LINE_MASK))))
+
+/*
+ * This variant of BN_mod_exp_mont() uses fixed windows and the special
+ * precomputation memory layout to limit data-dependency to a minimum to
+ * protect secret exponents (cf. the hyper-threading timing attacks pointed
+ * out by Colin Percival,
+ * http://www.daemong-consideredperthreading-considered-harmful/)
  */
 int BN_mod_exp_mont_consttime(BIGNUM *rr, const BIGNUM *a, const BIGNUM *p,
-		    const BIGNUM *m, BN_CTX *ctx, BN_MONT_CTX *in_mont)
-	{
-	int i,bits,ret=0,window,wvalue;
-	int top;
-	BN_MONT_CTX *mont=NULL;
-
-	int numPowers;
-	unsigned char *powerbufFree=NULL;
-	int powerbufLen = 0;
-	unsigned char *powerbuf=NULL;
-	BIGNUM tmp, am;
-
-	bn_check_top(a);
-	bn_check_top(p);
-	bn_check_top(m);
-
-	top = m->top;
-
-	if (!(m->d[0] & 1))
-		{
-		BNerr(BN_F_BN_MOD_EXP_MONT_CONSTTIME,BN_R_CALLED_WITH_EVEN_MODULUS);
-		return(0);
-		}
-	bits=BN_num_bits(p);
-	if (bits == 0)
-		{
-		ret = BN_one(rr);
-		return ret;
-		}
-
-	BN_CTX_start(ctx);
-
-	/* Allocate a montgomery context if it was not supplied by the caller.
-	 * If this is not done, things will break in the montgomery part.
- 	 */
-	if (in_mont != NULL)
-		mont=in_mont;
-	else
-		{
-		if ((mont=BN_MONT_CTX_new()) == NULL) goto err;
-		if (!BN_MONT_CTX_set(mont,m,ctx)) goto err;
-		}
-
-	/* Get the window size to use with size of p. */
-	window = BN_window_bits_for_ctime_exponent_size(bits);
-#if defined(OPENSSL_BN_ASM_MONT5)
-	if (window==6 && bits<=1024) window=5;	/* ~5% improvement of 2048-bit RSA sign */
+                              const BIGNUM *m, BN_CTX *ctx,
+                              BN_MONT_CTX *in_mont)
+{
+    int i, bits, ret = 0, window, wvalue;
+    int top;
+    BN_MONT_CTX *mont = NULL;
+
+    int numPowers;
+    unsigned char *powerbufFree = NULL;
+    int powerbufLen = 0;
+    unsigned char *powerbuf = NULL;
+    BIGNUM tmp, am;
+#if defined(SPARC_T4_MONT)
+    unsigned int t4 = 0;
 #endif
 
-	/* Allocate a buffer large enough to hold all of the pre-computed
-	 * powers of am, am itself and tmp.
-	 */
-	numPowers = 1 << window;
-	powerbufLen = sizeof(m->d[0])*(top*numPowers +
-				((2*top)>numPowers?(2*top):numPowers));
-#ifdef alloca
-	if (powerbufLen < 3072)
-		powerbufFree = alloca(powerbufLen+MOD_EXP_CTIME_MIN_CACHE_LINE_WIDTH);
-	else
+    bn_check_top(a);
+    bn_check_top(p);
+    bn_check_top(m);
+
+    top = m->top;
+
+    if (!(m->d[0] & 1)) {
+        BNerr(BN_F_BN_MOD_EXP_MONT_CONSTTIME, BN_R_CALLED_WITH_EVEN_MODULUS);
+        return (0);
+    }
+    bits = BN_num_bits(p);
+    if (bits == 0) {
+        ret = BN_one(rr);
+        return ret;
+    }
+
+    BN_CTX_start(ctx);
+
+    /*
+     * Allocate a montgomery context if it was not supplied by the caller. If
+     * this is not done, things will break in the montgomery part.
+     */
+    if (in_mont != NULL)
+        mont = in_mont;
+    else {
+        if ((mont = BN_MONT_CTX_new()) == NULL)
+            goto err;
+        if (!BN_MONT_CTX_set(mont, m, ctx))
+            goto err;
+    }
+
+#ifdef RSAZ_ENABLED
+    /*
+     * If the size of the operands allow it, perform the optimized
+     * RSAZ exponentiation. For further information see
+     * crypto/bn/rsaz_exp.c and accompanying assembly modules.
+     */
+    if ((16 == a->top) && (16 == p->top) && (BN_num_bits(m) == 1024)
+        && rsaz_avx2_eligible()) {
+        if (NULL == bn_wexpand(rr, 16))
+            goto err;
+        RSAZ_1024_mod_exp_avx2(rr->d, a->d, p->d, m->d, mont->RR.d,
+                               mont->n0[0]);
+        rr->top = 16;
+        rr->neg = 0;
+        bn_correct_top(rr);
+        ret = 1;
+        goto err;
+    } else if ((8 == a->top) && (8 == p->top) && (BN_num_bits(m) == 512)) {
+        if (NULL == bn_wexpand(rr, 8))
+            goto err;
+        RSAZ_512_mod_exp(rr->d, a->d, p->d, m->d, mont->n0[0], mont->RR.d);
+        rr->top = 8;
+        rr->neg = 0;
+        bn_correct_top(rr);
+        ret = 1;
+        goto err;
+    }
 #endif
-	if ((powerbufFree=(unsigned char*)OPENSSL_malloc(powerbufLen+MOD_EXP_CTIME_MIN_CACHE_LINE_WIDTH)) == NULL)
-		goto err;
-		
-	powerbuf = MOD_EXP_CTIME_ALIGN(powerbufFree);
-	memset(powerbuf, 0, powerbufLen);
 
+    /* Get the window size to use with size of p. */
+    window = BN_window_bits_for_ctime_exponent_size(bits);
+#if defined(SPARC_T4_MONT)
+    if (window >= 5 && (top & 15) == 0 && top <= 64 &&
+        (OPENSSL_sparcv9cap_P[1] & (CFR_MONTMUL | CFR_MONTSQR)) ==
+        (CFR_MONTMUL | CFR_MONTSQR) && (t4 = OPENSSL_sparcv9cap_P[0]))
+        window = 5;
+    else
+#endif
+#if defined(OPENSSL_BN_ASM_MONT5)
+    if (window >= 5) {
+        window = 5;             /* ~5% improvement for RSA2048 sign, and even
+                                 * for RSA4096 */
+        if ((top & 7) == 0)
+            powerbufLen += 2 * top * sizeof(m->d[0]);
+    }
+#endif
+    (void)0;
+
+    /*
+     * Allocate a buffer large enough to hold all of the pre-computed powers
+     * of am, am itself and tmp.
+     */
+    numPowers = 1 << window;
+    powerbufLen += sizeof(m->d[0]) * (top * numPowers +
+                                      ((2 * top) >
+                                       numPowers ? (2 * top) : numPowers));
 #ifdef alloca
-	if (powerbufLen < 3072)
-		powerbufFree = NULL;
+    if (powerbufLen < 3072)
+        powerbufFree =
+            alloca(powerbufLen + MOD_EXP_CTIME_MIN_CACHE_LINE_WIDTH);
+    else
 #endif
+        if ((powerbufFree =
+             (unsigned char *)OPENSSL_malloc(powerbufLen +
+                                             MOD_EXP_CTIME_MIN_CACHE_LINE_WIDTH))
+            == NULL)
+        goto err;
 
-	/* lay down tmp and am right after powers table */
-	tmp.d     = (BN_ULONG *)(powerbuf + sizeof(m->d[0])*top*numPowers);
-	am.d      = tmp.d + top;
-	tmp.top   = am.top  = 0;
-	tmp.dmax  = am.dmax = top;
-	tmp.neg   = am.neg  = 0;
-	tmp.flags = am.flags = BN_FLG_STATIC_DATA;
-
-	/* prepare a^0 in Montgomery domain */
-#if 1
- 	if (!BN_to_montgomery(&tmp,BN_value_one(),mont,ctx))	goto err;
-#else
-	tmp.d[0] = (0-m->d[0])&BN_MASK2;	/* 2^(top*BN_BITS2) - m */
-	for (i=1;i<top;i++)
-		tmp.d[i] = (~m->d[i])&BN_MASK2;
-	tmp.top = top;
-#endif
+    powerbuf = MOD_EXP_CTIME_ALIGN(powerbufFree);
+    memset(powerbuf, 0, powerbufLen);
 
-	/* prepare a^1 in Montgomery domain */
-	if (a->neg || BN_ucmp(a,m) >= 0)
-		{
-		if (!BN_mod(&am,a,m,ctx))			goto err;
-		if (!BN_to_montgomery(&am,&am,mont,ctx))	goto err;
-		}
-	else	if (!BN_to_montgomery(&am,a,mont,ctx))		goto err;
+#ifdef alloca
+    if (powerbufLen < 3072)
+        powerbufFree = NULL;
+#endif
 
+    /* lay down tmp and am right after powers table */
+    tmp.d = (BN_ULONG *)(powerbuf + sizeof(m->d[0]) * top * numPowers);
+    am.d = tmp.d + top;
+    tmp.top = am.top = 0;
+    tmp.dmax = am.dmax = top;
+    tmp.neg = am.neg = 0;
+    tmp.flags = am.flags = BN_FLG_STATIC_DATA;
+
+    /* prepare a^0 in Montgomery domain */
+#if 1                           /* by Shay Gueron's suggestion */
+    if (m->d[top - 1] & (((BN_ULONG)1) << (BN_BITS2 - 1))) {
+        /* 2^(top*BN_BITS2) - m */
+        tmp.d[0] = (0 - m->d[0]) & BN_MASK2;
+        for (i = 1; i < top; i++)
+            tmp.d[i] = (~m->d[i]) & BN_MASK2;
+        tmp.top = top;
+    } else
+#endif
+    if (!BN_to_montgomery(&tmp, BN_value_one(), mont, ctx))
+        goto err;
+
+    /* prepare a^1 in Montgomery domain */
+    if (a->neg || BN_ucmp(a, m) >= 0) {
+        if (!BN_mod(&am, a, m, ctx))
+            goto err;
+        if (!BN_to_montgomery(&am, &am, mont, ctx))
+            goto err;
+    } else if (!BN_to_montgomery(&am, a, mont, ctx))
+        goto err;
+
+#if defined(SPARC_T4_MONT)
+    if (t4) {
+        typedef int (*bn_pwr5_mont_f) (BN_ULONG *tp, const BN_ULONG *np,
+                                       const BN_ULONG *n0, const void *table,
+                                       int power, int bits);
+        int bn_pwr5_mont_t4_8(BN_ULONG *tp, const BN_ULONG *np,
+                              const BN_ULONG *n0, const void *table,
+                              int power, int bits);
+        int bn_pwr5_mont_t4_16(BN_ULONG *tp, const BN_ULONG *np,
+                               const BN_ULONG *n0, const void *table,
+                               int power, int bits);
+        int bn_pwr5_mont_t4_24(BN_ULONG *tp, const BN_ULONG *np,
+                               const BN_ULONG *n0, const void *table,
+                               int power, int bits);
+        int bn_pwr5_mont_t4_32(BN_ULONG *tp, const BN_ULONG *np,
+                               const BN_ULONG *n0, const void *table,
+                               int power, int bits);
+        static const bn_pwr5_mont_f pwr5_funcs[4] = {
+            bn_pwr5_mont_t4_8, bn_pwr5_mont_t4_16,
+            bn_pwr5_mont_t4_24, bn_pwr5_mont_t4_32
+        };
+        bn_pwr5_mont_f pwr5_worker = pwr5_funcs[top / 16 - 1];
+
+        typedef int (*bn_mul_mont_f) (BN_ULONG *rp, const BN_ULONG *ap,
+                                      const void *bp, const BN_ULONG *np,
+                                      const BN_ULONG *n0);
+        int bn_mul_mont_t4_8(BN_ULONG *rp, const BN_ULONG *ap, const void *bp,
+                             const BN_ULONG *np, const BN_ULONG *n0);
+        int bn_mul_mont_t4_16(BN_ULONG *rp, const BN_ULONG *ap,
+                              const void *bp, const BN_ULONG *np,
+                              const BN_ULONG *n0);
+        int bn_mul_mont_t4_24(BN_ULONG *rp, const BN_ULONG *ap,
+                              const void *bp, const BN_ULONG *np,
+                              const BN_ULONG *n0);
+        int bn_mul_mont_t4_32(BN_ULONG *rp, const BN_ULONG *ap,
+                              const void *bp, const BN_ULONG *np,
+                              const BN_ULONG *n0);
+        static const bn_mul_mont_f mul_funcs[4] = {
+            bn_mul_mont_t4_8, bn_mul_mont_t4_16,
+            bn_mul_mont_t4_24, bn_mul_mont_t4_32
+        };
+        bn_mul_mont_f mul_worker = mul_funcs[top / 16 - 1];
+
+        void bn_mul_mont_vis3(BN_ULONG *rp, const BN_ULONG *ap,
+                              const void *bp, const BN_ULONG *np,
+                              const BN_ULONG *n0, int num);
+        void bn_mul_mont_t4(BN_ULONG *rp, const BN_ULONG *ap,
+                            const void *bp, const BN_ULONG *np,
+                            const BN_ULONG *n0, int num);
+        void bn_mul_mont_gather5_t4(BN_ULONG *rp, const BN_ULONG *ap,
+                                    const void *table, const BN_ULONG *np,
+                                    const BN_ULONG *n0, int num, int power);
+        void bn_flip_n_scatter5_t4(const BN_ULONG *inp, size_t num,
+                                   void *table, size_t power);
+        void bn_gather5_t4(BN_ULONG *out, size_t num,
+                           void *table, size_t power);
+        void bn_flip_t4(BN_ULONG *dst, BN_ULONG *src, size_t num);
+
+        BN_ULONG *np = mont->N.d, *n0 = mont->n0;
+        int stride = 5 * (6 - (top / 16 - 1)); /* multiple of 5, but less
+                                                * than 32 */
+
+        /*
+         * BN_to_montgomery can contaminate words above .top [in
+         * BN_DEBUG[_DEBUG] build]...
+         */
+        for (i = am.top; i < top; i++)
+            am.d[i] = 0;
+        for (i = tmp.top; i < top; i++)
+            tmp.d[i] = 0;
+
+        bn_flip_n_scatter5_t4(tmp.d, top, powerbuf, 0);
+        bn_flip_n_scatter5_t4(am.d, top, powerbuf, 1);
+        if (!(*mul_worker) (tmp.d, am.d, am.d, np, n0) &&
+            !(*mul_worker) (tmp.d, am.d, am.d, np, n0))
+            bn_mul_mont_vis3(tmp.d, am.d, am.d, np, n0, top);
+        bn_flip_n_scatter5_t4(tmp.d, top, powerbuf, 2);
+
+        for (i = 3; i < 32; i++) {
+            /* Calculate a^i = a^(i-1) * a */
+            if (!(*mul_worker) (tmp.d, tmp.d, am.d, np, n0) &&
+                !(*mul_worker) (tmp.d, tmp.d, am.d, np, n0))
+                bn_mul_mont_vis3(tmp.d, tmp.d, am.d, np, n0, top);
+            bn_flip_n_scatter5_t4(tmp.d, top, powerbuf, i);
+        }
+
+        /* switch to 64-bit domain */
+        np = alloca(top * sizeof(BN_ULONG));
+        top /= 2;
+        bn_flip_t4(np, mont->N.d, top);
+
+        bits--;
+        for (wvalue = 0, i = bits % 5; i >= 0; i--, bits--)
+            wvalue = (wvalue << 1) + BN_is_bit_set(p, bits);
+        bn_gather5_t4(tmp.d, top, powerbuf, wvalue);
+
+        /*
+         * Scan the exponent one window at a time starting from the most
+         * significant bits.
+         */
+        while (bits >= 0) {
+            if (bits < stride)
+                stride = bits + 1;
+            bits -= stride;
+            wvalue = bn_get_bits(p, bits + 1);
+
+            if ((*pwr5_worker) (tmp.d, np, n0, powerbuf, wvalue, stride))
+                continue;
+            /* retry once and fall back */
+            if ((*pwr5_worker) (tmp.d, np, n0, powerbuf, wvalue, stride))
+                continue;
+
+            bits += stride - 5;
+            wvalue >>= stride - 5;
+            wvalue &= 31;
+            bn_mul_mont_t4(tmp.d, tmp.d, tmp.d, np, n0, top);
+            bn_mul_mont_t4(tmp.d, tmp.d, tmp.d, np, n0, top);
+            bn_mul_mont_t4(tmp.d, tmp.d, tmp.d, np, n0, top);
+            bn_mul_mont_t4(tmp.d, tmp.d, tmp.d, np, n0, top);
+            bn_mul_mont_t4(tmp.d, tmp.d, tmp.d, np, n0, top);
+            bn_mul_mont_gather5_t4(tmp.d, tmp.d, powerbuf, np, n0, top,
+                                   wvalue);
+        }
+
+        bn_flip_t4(tmp.d, tmp.d, top);
+        top *= 2;
+        /* back to 32-bit domain */
+        tmp.top = top;
+        bn_correct_top(&tmp);
+        OPENSSL_cleanse(np, top * sizeof(BN_ULONG));
+    } else
+#endif
 #if defined(OPENSSL_BN_ASM_MONT5)
-    /* This optimization uses ideas from http://eprint.iacr.org/2011/239,
-     * specifically optimization of cache-timing attack countermeasures
-     * and pre-computation optimization. */
-
-    /* Dedicated window==4 case improves 512-bit RSA sign by ~15%, but as
-     * 512-bit RSA is hardly relevant, we omit it to spare size... */ 
-    if (window==5 && top>1)
-	{
-	void bn_mul_mont_gather5(BN_ULONG *rp,const BN_ULONG *ap,
-			const void *table,const BN_ULONG *np,
-			const BN_ULONG *n0,int num,int power);
-	void bn_scatter5(const BN_ULONG *inp,size_t num,
-			void *table,size_t power);
-	void bn_gather5(BN_ULONG *out,size_t num,
-			void *table,size_t power);
-
-	BN_ULONG *np=mont->N.d, *n0=mont->n0;
-
-	/* BN_to_montgomery can contaminate words above .top
-	 * [in BN_DEBUG[_DEBUG] build]... */
-	for (i=am.top; i<top; i++)	am.d[i]=0;
-	for (i=tmp.top; i<top; i++)	tmp.d[i]=0;
-
-	bn_scatter5(tmp.d,top,powerbuf,0);
-	bn_scatter5(am.d,am.top,powerbuf,1);
-	bn_mul_mont(tmp.d,am.d,am.d,np,n0,top);
-	bn_scatter5(tmp.d,top,powerbuf,2);
-
-#if 0
-	for (i=3; i<32; i++)
-		{
-		/* Calculate a^i = a^(i-1) * a */
-		bn_mul_mont_gather5(tmp.d,am.d,powerbuf,np,n0,top,i-1);
-		bn_scatter5(tmp.d,top,powerbuf,i);
-		}
-#else
-	/* same as above, but uses squaring for 1/2 of operations */
-	for (i=4; i<32; i*=2)
-		{
-		bn_mul_mont(tmp.d,tmp.d,tmp.d,np,n0,top);
-		bn_scatter5(tmp.d,top,powerbuf,i);
-		}
-	for (i=3; i<8; i+=2)
-		{
-		int j;
-		bn_mul_mont_gather5(tmp.d,am.d,powerbuf,np,n0,top,i-1);
-		bn_scatter5(tmp.d,top,powerbuf,i);
-		for (j=2*i; j<32; j*=2)
-			{
-			bn_mul_mont(tmp.d,tmp.d,tmp.d,np,n0,top);
-			bn_scatter5(tmp.d,top,powerbuf,j);
-			}
-		}
-	for (; i<16; i+=2)
-		{
-		bn_mul_mont_gather5(tmp.d,am.d,powerbuf,np,n0,top,i-1);
-		bn_scatter5(tmp.d,top,powerbuf,i);
-		bn_mul_mont(tmp.d,tmp.d,tmp.d,np,n0,top);
-		bn_scatter5(tmp.d,top,powerbuf,2*i);
-		}
-	for (; i<32; i+=2)
-		{
-		bn_mul_mont_gather5(tmp.d,am.d,powerbuf,np,n0,top,i-1);
-		bn_scatter5(tmp.d,top,powerbuf,i);
-		}
+    if (window == 5 && top > 1) {
+        /*
+         * This optimization uses ideas from http://eprint.iacr.org/2011/239,
+         * specifically optimization of cache-timing attack countermeasures
+         * and pre-computation optimization.
+         */
+
+        /*
+         * Dedicated window==4 case improves 512-bit RSA sign by ~15%, but as
+         * 512-bit RSA is hardly relevant, we omit it to spare size...
+         */
+        void bn_mul_mont_gather5(BN_ULONG *rp, const BN_ULONG *ap,
+                                 const void *table, const BN_ULONG *np,
+                                 const BN_ULONG *n0, int num, int power);
+        void bn_scatter5(const BN_ULONG *inp, size_t num,
+                         void *table, size_t power);
+        void bn_gather5(BN_ULONG *out, size_t num, void *table, size_t power);
+        void bn_power5(BN_ULONG *rp, const BN_ULONG *ap,
+                       const void *table, const BN_ULONG *np,
+                       const BN_ULONG *n0, int num, int power);
+        int bn_get_bits5(const BN_ULONG *ap, int off);
+        int bn_from_montgomery(BN_ULONG *rp, const BN_ULONG *ap,
+                               const BN_ULONG *not_used, const BN_ULONG *np,
+                               const BN_ULONG *n0, int num);
+
+        BN_ULONG *np = mont->N.d, *n0 = mont->n0, *np2;
+
+        /*
+         * BN_to_montgomery can contaminate words above .top [in
+         * BN_DEBUG[_DEBUG] build]...
+         */
+        for (i = am.top; i < top; i++)
+            am.d[i] = 0;
+        for (i = tmp.top; i < top; i++)
+            tmp.d[i] = 0;
+
+        if (top & 7)
+            np2 = np;
+        else
+            for (np2 = am.d + top, i = 0; i < top; i++)
+                np2[2 * i] = np[i];
+
+        bn_scatter5(tmp.d, top, powerbuf, 0);
+        bn_scatter5(am.d, am.top, powerbuf, 1);
+        bn_mul_mont(tmp.d, am.d, am.d, np, n0, top);
+        bn_scatter5(tmp.d, top, powerbuf, 2);
+
+# if 0
+        for (i = 3; i < 32; i++) {
+            /* Calculate a^i = a^(i-1) * a */
+            bn_mul_mont_gather5(tmp.d, am.d, powerbuf, np2, n0, top, i - 1);
+            bn_scatter5(tmp.d, top, powerbuf, i);
+        }
+# else
+        /* same as above, but uses squaring for 1/2 of operations */
+        for (i = 4; i < 32; i *= 2) {
+            bn_mul_mont(tmp.d, tmp.d, tmp.d, np, n0, top);
+            bn_scatter5(tmp.d, top, powerbuf, i);
+        }
+        for (i = 3; i < 8; i += 2) {
+            int j;
+            bn_mul_mont_gather5(tmp.d, am.d, powerbuf, np2, n0, top, i - 1);
+            bn_scatter5(tmp.d, top, powerbuf, i);
+            for (j = 2 * i; j < 32; j *= 2) {
+                bn_mul_mont(tmp.d, tmp.d, tmp.d, np, n0, top);
+                bn_scatter5(tmp.d, top, powerbuf, j);
+            }
+        }
+        for (; i < 16; i += 2) {
+            bn_mul_mont_gather5(tmp.d, am.d, powerbuf, np2, n0, top, i - 1);
+            bn_scatter5(tmp.d, top, powerbuf, i);
+            bn_mul_mont(tmp.d, tmp.d, tmp.d, np, n0, top);
+            bn_scatter5(tmp.d, top, powerbuf, 2 * i);
+        }
+        for (; i < 32; i += 2) {
+            bn_mul_mont_gather5(tmp.d, am.d, powerbuf, np2, n0, top, i - 1);
+            bn_scatter5(tmp.d, top, powerbuf, i);
+        }
+# endif
+        bits--;
+        for (wvalue = 0, i = bits % 5; i >= 0; i--, bits--)
+            wvalue = (wvalue << 1) + BN_is_bit_set(p, bits);
+        bn_gather5(tmp.d, top, powerbuf, wvalue);
+
+        /*
+         * Scan the exponent one window at a time starting from the most
+         * significant bits.
+         */
+        if (top & 7)
+            while (bits >= 0) {
+                for (wvalue = 0, i = 0; i < 5; i++, bits--)
+                    wvalue = (wvalue << 1) + BN_is_bit_set(p, bits);
+
+                bn_mul_mont(tmp.d, tmp.d, tmp.d, np, n0, top);
+                bn_mul_mont(tmp.d, tmp.d, tmp.d, np, n0, top);
+                bn_mul_mont(tmp.d, tmp.d, tmp.d, np, n0, top);
+                bn_mul_mont(tmp.d, tmp.d, tmp.d, np, n0, top);
+                bn_mul_mont(tmp.d, tmp.d, tmp.d, np, n0, top);
+                bn_mul_mont_gather5(tmp.d, tmp.d, powerbuf, np, n0, top,
+                                    wvalue);
+        } else {
+            while (bits >= 0) {
+                wvalue = bn_get_bits5(p->d, bits - 4);
+                bits -= 5;
+                bn_power5(tmp.d, tmp.d, powerbuf, np2, n0, top, wvalue);
+            }
+        }
+
+        ret = bn_from_montgomery(tmp.d, tmp.d, NULL, np2, n0, top);
+        tmp.top = top;
+        bn_correct_top(&tmp);
+        if (ret) {
+            if (!BN_copy(rr, &tmp))
+                ret = 0;
+            goto err;           /* non-zero ret means it's not error */
+        }
+    } else
 #endif
-	bits--;
-	for (wvalue=0, i=bits%5; i>=0; i--,bits--)
-		wvalue = (wvalue<<1)+BN_is_bit_set(p,bits);
-	bn_gather5(tmp.d,top,powerbuf,wvalue);
-
-	/* Scan the exponent one window at a time starting from the most
-	 * significant bits.
-	 */
-	while (bits >= 0)
-		{
-		for (wvalue=0, i=0; i<5; i++,bits--)
-			wvalue = (wvalue<<1)+BN_is_bit_set(p,bits);
-
-		bn_mul_mont(tmp.d,tmp.d,tmp.d,np,n0,top);
-		bn_mul_mont(tmp.d,tmp.d,tmp.d,np,n0,top);
-		bn_mul_mont(tmp.d,tmp.d,tmp.d,np,n0,top);
-		bn_mul_mont(tmp.d,tmp.d,tmp.d,np,n0,top);
-		bn_mul_mont(tmp.d,tmp.d,tmp.d,np,n0,top);
-		bn_mul_mont_gather5(tmp.d,tmp.d,powerbuf,np,n0,top,wvalue);
-		}
-
-	tmp.top=top;
-	bn_correct_top(&tmp);
-	}
-    else
+    {
+        if (!MOD_EXP_CTIME_COPY_TO_PREBUF(&tmp, top, powerbuf, 0, numPowers))
+            goto err;
+        if (!MOD_EXP_CTIME_COPY_TO_PREBUF(&am, top, powerbuf, 1, numPowers))
+            goto err;
+
+        /*
+         * If the window size is greater than 1, then calculate
+         * val[i=2..2^winsize-1]. Powers are computed as a*a^(i-1) (even
+         * powers could instead be computed as (a^(i/2))^2 to use the slight
+         * performance advantage of sqr over mul).
+         */
+        if (window > 1) {
+            if (!BN_mod_mul_montgomery(&tmp, &am, &am, mont, ctx))
+                goto err;
+            if (!MOD_EXP_CTIME_COPY_TO_PREBUF
+                (&tmp, top, powerbuf, 2, numPowers))
+                goto err;
+            for (i = 3; i < numPowers; i++) {
+                /* Calculate a^i = a^(i-1) * a */
+                if (!BN_mod_mul_montgomery(&tmp, &am, &tmp, mont, ctx))
+                    goto err;
+                if (!MOD_EXP_CTIME_COPY_TO_PREBUF
+                    (&tmp, top, powerbuf, i, numPowers))
+                    goto err;
+            }
+        }
+
+        bits--;
+        for (wvalue = 0, i = bits % window; i >= 0; i--, bits--)
+            wvalue = (wvalue << 1) + BN_is_bit_set(p, bits);
+        if (!MOD_EXP_CTIME_COPY_FROM_PREBUF
+            (&tmp, top, powerbuf, wvalue, numPowers))
+            goto err;
+
+        /*
+         * Scan the exponent one window at a time starting from the most
+         * significant bits.
+         */
+        while (bits >= 0) {
+            wvalue = 0;         /* The 'value' of the window */
+
+            /* Scan the window, squaring the result as we go */
+            for (i = 0; i < window; i++, bits--) {
+                if (!BN_mod_mul_montgomery(&tmp, &tmp, &tmp, mont, ctx))
+                    goto err;
+                wvalue = (wvalue << 1) + BN_is_bit_set(p, bits);
+            }
+
+            /*
+             * Fetch the appropriate pre-computed value from the pre-buf
+             */
+            if (!MOD_EXP_CTIME_COPY_FROM_PREBUF
+                (&am, top, powerbuf, wvalue, numPowers))
+                goto err;
+
+            /* Multiply the result into the intermediate result */
+            if (!BN_mod_mul_montgomery(&tmp, &tmp, &am, mont, ctx))
+                goto err;
+        }
+    }
+
+    /* Convert the final result from montgomery to standard format */
+#if defined(SPARC_T4_MONT)
+    if (OPENSSL_sparcv9cap_P[0] & (SPARCV9_VIS3 | SPARCV9_PREFER_FPU)) {
+        am.d[0] = 1;            /* borrow am */
+        for (i = 1; i < top; i++)
+            am.d[i] = 0;
+        if (!BN_mod_mul_montgomery(rr, &tmp, &am, mont, ctx))
+            goto err;
+    } else
 #endif
-	{
-	if (!MOD_EXP_CTIME_COPY_TO_PREBUF(&tmp, top, powerbuf, 0, numPowers)) goto err;
-	if (!MOD_EXP_CTIME_COPY_TO_PREBUF(&am,  top, powerbuf, 1, numPowers)) goto err;
-
-	/* If the window size is greater than 1, then calculate
-	 * val[i=2..2^winsize-1]. Powers are computed as a*a^(i-1)
-	 * (even powers could instead be computed as (a^(i/2))^2
-	 * to use the slight performance advantage of sqr over mul).
-	 */
-	if (window > 1)
-		{
-		if (!BN_mod_mul_montgomery(&tmp,&am,&am,mont,ctx))	goto err;
-		if (!MOD_EXP_CTIME_COPY_TO_PREBUF(&tmp, top, powerbuf, 2, numPowers)) goto err;
-		for (i=3; i<numPowers; i++)
-			{
-			/* Calculate a^i = a^(i-1) * a */
-			if (!BN_mod_mul_montgomery(&tmp,&am,&tmp,mont,ctx))
-				goto err;
-			if (!MOD_EXP_CTIME_COPY_TO_PREBUF(&tmp, top, powerbuf, i, numPowers)) goto err;
-			}
-		}
-
-	bits--;
-	for (wvalue=0, i=bits%window; i>=0; i--,bits--)
-		wvalue = (wvalue<<1)+BN_is_bit_set(p,bits);
-	if (!MOD_EXP_CTIME_COPY_FROM_PREBUF(&tmp,top,powerbuf,wvalue,numPowers)) goto err;
- 
-	/* Scan the exponent one window at a time starting from the most
-	 * significant bits.
-	 */
- 	while (bits >= 0)
-  		{
- 		wvalue=0; /* The 'value' of the window */
- 		
- 		/* Scan the window, squaring the result as we go */
- 		for (i=0; i<window; i++,bits--)
- 			{
-			if (!BN_mod_mul_montgomery(&tmp,&tmp,&tmp,mont,ctx))	goto err;
-			wvalue = (wvalue<<1)+BN_is_bit_set(p,bits);
-  			}
- 		
-		/* Fetch the appropriate pre-computed value from the pre-buf */
-		if (!MOD_EXP_CTIME_COPY_FROM_PREBUF(&am, top, powerbuf, wvalue, numPowers)) goto err;
-
- 		/* Multiply the result into the intermediate result */
- 		if (!BN_mod_mul_montgomery(&tmp,&tmp,&am,mont,ctx)) goto err;
-  		}
-	}
-
- 	/* Convert the final result from montgomery to standard format */
-	if (!BN_from_montgomery(rr,&tmp,mont,ctx)) goto err;
-	ret=1;
-err:
-	if ((in_mont == NULL) && (mont != NULL)) BN_MONT_CTX_free(mont);
-	if (powerbuf!=NULL)
-		{
-		OPENSSL_cleanse(powerbuf,powerbufLen);
-		if (powerbufFree) OPENSSL_free(powerbufFree);
-		}
-	BN_CTX_end(ctx);
-	return(ret);
-	}
+    if (!BN_from_montgomery(rr, &tmp, mont, ctx))
+        goto err;
+    ret = 1;
+ err:
+    if ((in_mont == NULL) && (mont != NULL))
+        BN_MONT_CTX_free(mont);
+    if (powerbuf != NULL) {
+        OPENSSL_cleanse(powerbuf, powerbufLen);
+        if (powerbufFree)
+            OPENSSL_free(powerbufFree);
+    }
+    BN_CTX_end(ctx);
+    return (ret);
+}
 
 int BN_mod_exp_mont_word(BIGNUM *rr, BN_ULONG a, const BIGNUM *p,
                          const BIGNUM *m, BN_CTX *ctx, BN_MONT_CTX *in_mont)
-	{
-	BN_MONT_CTX *mont = NULL;
-	int b, bits, ret=0;
-	int r_is_one;
-	BN_ULONG w, next_w;
-	BIGNUM *d, *r, *t;
-	BIGNUM *swap_tmp;
+{
+    BN_MONT_CTX *mont = NULL;
+    int b, bits, ret = 0;
+    int r_is_one;
+    BN_ULONG w, next_w;
+    BIGNUM *d, *r, *t;
+    BIGNUM *swap_tmp;
 #define BN_MOD_MUL_WORD(r, w, m) \
-		(BN_mul_word(r, (w)) && \
-		(/* BN_ucmp(r, (m)) < 0 ? 1 :*/  \
-			(BN_mod(t, r, m, ctx) && (swap_tmp = r, r = t, t = swap_tmp, 1))))
-		/* BN_MOD_MUL_WORD is only used with 'w' large,
-		 * so the BN_ucmp test is probably more overhead
-		 * than always using BN_mod (which uses BN_copy if
-		 * a similar test returns true). */
-		/* We can use BN_mod and do not need BN_nnmod because our
-		 * accumulator is never negative (the result of BN_mod does
-		 * not depend on the sign of the modulus).
-		 */
+                (BN_mul_word(r, (w)) && \
+                (/* BN_ucmp(r, (m)) < 0 ? 1 :*/  \
+                        (BN_mod(t, r, m, ctx) && (swap_tmp = r, r = t, t = swap_tmp, 1))))
+    /*
+     * BN_MOD_MUL_WORD is only used with 'w' large, so the BN_ucmp test is
+     * probably more overhead than always using BN_mod (which uses BN_copy if
+     * a similar test returns true).
+     */
+    /*
+     * We can use BN_mod and do not need BN_nnmod because our accumulator is
+     * never negative (the result of BN_mod does not depend on the sign of
+     * the modulus).
+     */
 #define BN_TO_MONTGOMERY_WORD(r, w, mont) \
-		(BN_set_word(r, (w)) && BN_to_montgomery(r, r, (mont), ctx))
-
-	if (BN_get_flags(p, BN_FLG_CONSTTIME) != 0)
-		{
-		/* BN_FLG_CONSTTIME only supported by BN_mod_exp_mont() */
-		BNerr(BN_F_BN_MOD_EXP_MONT_WORD,ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
-		return -1;
-		}
-
-	bn_check_top(p);
-	bn_check_top(m);
-
-	if (!BN_is_odd(m))
-		{
-		BNerr(BN_F_BN_MOD_EXP_MONT_WORD,BN_R_CALLED_WITH_EVEN_MODULUS);
-		return(0);
-		}
-	if (m->top == 1)
-		a %= m->d[0]; /* make sure that 'a' is reduced */
-
-	bits = BN_num_bits(p);
-	if (bits == 0)
-		{
-		/* x**0 mod 1 is still zero. */
-		if (BN_is_one(m))
-			{
-			ret = 1;
-			BN_zero(rr);
-			}
-		else
-			ret = BN_one(rr);
-		return ret;
-		}
-	if (a == 0)
-		{
-		BN_zero(rr);
-		ret = 1;
-		return ret;
-		}
-
-	BN_CTX_start(ctx);
-	d = BN_CTX_get(ctx);
-	r = BN_CTX_get(ctx);
-	t = BN_CTX_get(ctx);
-	if (d == NULL || r == NULL || t == NULL) goto err;
-
-	if (in_mont != NULL)
-		mont=in_mont;
-	else
-		{
-		if ((mont = BN_MONT_CTX_new()) == NULL) goto err;
-		if (!BN_MONT_CTX_set(mont, m, ctx)) goto err;
-		}
-
-	r_is_one = 1; /* except for Montgomery factor */
-
-	/* bits-1 >= 0 */
-
-	/* The result is accumulated in the product r*w. */
-	w = a; /* bit 'bits-1' of 'p' is always set */
-	for (b = bits-2; b >= 0; b--)
-		{
-		/* First, square r*w. */
-		next_w = w*w;
-		if ((next_w/w) != w) /* overflow */
-			{
-			if (r_is_one)
-				{
-				if (!BN_TO_MONTGOMERY_WORD(r, w, mont)) goto err;
-				r_is_one = 0;
-				}
-			else
-				{
-				if (!BN_MOD_MUL_WORD(r, w, m)) goto err;
-				}
-			next_w = 1;
-			}
-		w = next_w;
-		if (!r_is_one)
-			{
-			if (!BN_mod_mul_montgomery(r, r, r, mont, ctx)) goto err;
-			}
-
-		/* Second, multiply r*w by 'a' if exponent bit is set. */
-		if (BN_is_bit_set(p, b))
-			{
-			next_w = w*a;
-			if ((next_w/a) != w) /* overflow */
-				{
-				if (r_is_one)
-					{
-					if (!BN_TO_MONTGOMERY_WORD(r, w, mont)) goto err;
-					r_is_one = 0;
-					}
-				else
-					{
-					if (!BN_MOD_MUL_WORD(r, w, m)) goto err;
-					}
-				next_w = a;
-				}
-			w = next_w;
-			}
-		}
-
-	/* Finally, set r:=r*w. */
-	if (w != 1)
-		{
-		if (r_is_one)
-			{
-			if (!BN_TO_MONTGOMERY_WORD(r, w, mont)) goto err;
-			r_is_one = 0;
-			}
-		else
-			{
-			if (!BN_MOD_MUL_WORD(r, w, m)) goto err;
-			}
-		}
-
-	if (r_is_one) /* can happen only if a == 1*/
-		{
-		if (!BN_one(rr)) goto err;
-		}
-	else
-		{
-		if (!BN_from_montgomery(rr, r, mont, ctx)) goto err;
-		}
-	ret = 1;
-err:
-	if ((in_mont == NULL) && (mont != NULL)) BN_MONT_CTX_free(mont);
-	BN_CTX_end(ctx);
-	bn_check_top(rr);
-	return(ret);
-	}
-
+                (BN_set_word(r, (w)) && BN_to_montgomery(r, r, (mont), ctx))
+
+    if (BN_get_flags(p, BN_FLG_CONSTTIME) != 0) {
+        /* BN_FLG_CONSTTIME only supported by BN_mod_exp_mont() */
+        BNerr(BN_F_BN_MOD_EXP_MONT_WORD, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
+        return -1;
+    }
+
+    bn_check_top(p);
+    bn_check_top(m);
+
+    if (!BN_is_odd(m)) {
+        BNerr(BN_F_BN_MOD_EXP_MONT_WORD, BN_R_CALLED_WITH_EVEN_MODULUS);
+        return (0);
+    }
+    if (m->top == 1)
+        a %= m->d[0];           /* make sure that 'a' is reduced */
+
+    bits = BN_num_bits(p);
+    if (bits == 0) {
+        /* x**0 mod 1 is still zero. */
+        if (BN_is_one(m)) {
+            ret = 1;
+            BN_zero(rr);
+        } else
+            ret = BN_one(rr);
+        return ret;
+    }
+    if (a == 0) {
+        BN_zero(rr);
+        ret = 1;
+        return ret;
+    }
+
+    BN_CTX_start(ctx);
+    d = BN_CTX_get(ctx);
+    r = BN_CTX_get(ctx);
+    t = BN_CTX_get(ctx);
+    if (d == NULL || r == NULL || t == NULL)
+        goto err;
+
+    if (in_mont != NULL)
+        mont = in_mont;
+    else {
+        if ((mont = BN_MONT_CTX_new()) == NULL)
+            goto err;
+        if (!BN_MONT_CTX_set(mont, m, ctx))
+            goto err;
+    }
+
+    r_is_one = 1;               /* except for Montgomery factor */
+
+    /* bits-1 >= 0 */
+
+    /* The result is accumulated in the product r*w. */
+    w = a;                      /* bit 'bits-1' of 'p' is always set */
+    for (b = bits - 2; b >= 0; b--) {
+        /* First, square r*w. */
+        next_w = w * w;
+        if ((next_w / w) != w) { /* overflow */
+            if (r_is_one) {
+                if (!BN_TO_MONTGOMERY_WORD(r, w, mont))
+                    goto err;
+                r_is_one = 0;
+            } else {
+                if (!BN_MOD_MUL_WORD(r, w, m))
+                    goto err;
+            }
+            next_w = 1;
+        }
+        w = next_w;
+        if (!r_is_one) {
+            if (!BN_mod_mul_montgomery(r, r, r, mont, ctx))
+                goto err;
+        }
+
+        /* Second, multiply r*w by 'a' if exponent bit is set. */
+        if (BN_is_bit_set(p, b)) {
+            next_w = w * a;
+            if ((next_w / a) != w) { /* overflow */
+                if (r_is_one) {
+                    if (!BN_TO_MONTGOMERY_WORD(r, w, mont))
+                        goto err;
+                    r_is_one = 0;
+                } else {
+                    if (!BN_MOD_MUL_WORD(r, w, m))
+                        goto err;
+                }
+                next_w = a;
+            }
+            w = next_w;
+        }
+    }
+
+    /* Finally, set r:=r*w. */
+    if (w != 1) {
+        if (r_is_one) {
+            if (!BN_TO_MONTGOMERY_WORD(r, w, mont))
+                goto err;
+            r_is_one = 0;
+        } else {
+            if (!BN_MOD_MUL_WORD(r, w, m))
+                goto err;
+        }
+    }
+
+    if (r_is_one) {             /* can happen only if a == 1 */
+        if (!BN_one(rr))
+            goto err;
+    } else {
+        if (!BN_from_montgomery(rr, r, mont, ctx))
+            goto err;
+    }
+    ret = 1;
+ err:
+    if ((in_mont == NULL) && (mont != NULL))
+        BN_MONT_CTX_free(mont);
+    BN_CTX_end(ctx);
+    bn_check_top(rr);
+    return (ret);
+}
 
 /* The old fallback, simple version :-) */
 int BN_mod_exp_simple(BIGNUM *r, const BIGNUM *a, const BIGNUM *p,
-		const BIGNUM *m, BN_CTX *ctx)
-	{
-	int i,j,bits,ret=0,wstart,wend,window,wvalue;
-	int start=1;
-	BIGNUM *d;
-	/* Table of variables obtained from 'ctx' */
-	BIGNUM *val[TABLE_SIZE];
-
-	if (BN_get_flags(p, BN_FLG_CONSTTIME) != 0)
-		{
-		/* BN_FLG_CONSTTIME only supported by BN_mod_exp_mont() */
-		BNerr(BN_F_BN_MOD_EXP_SIMPLE,ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
-		return -1;
-		}
-
-	bits=BN_num_bits(p);
-
-	if (bits == 0)
-		{
-		ret = BN_one(r);
-		return ret;
-		}
-
-	BN_CTX_start(ctx);
-	d = BN_CTX_get(ctx);
-	val[0] = BN_CTX_get(ctx);
-	if(!d || !val[0]) goto err;
-
-	if (!BN_nnmod(val[0],a,m,ctx)) goto err;		/* 1 */
-	if (BN_is_zero(val[0]))
-		{
-		BN_zero(r);
-		ret = 1;
-		goto err;
-		}
-
-	window = BN_window_bits_for_exponent_size(bits);
-	if (window > 1)
-		{
-		if (!BN_mod_mul(d,val[0],val[0],m,ctx))
-			goto err;				/* 2 */
-		j=1<<(window-1);
-		for (i=1; i<j; i++)
-			{
-			if(((val[i] = BN_CTX_get(ctx)) == NULL) ||
-					!BN_mod_mul(val[i],val[i-1],d,m,ctx))
-				goto err;
-			}
-		}
-
-	start=1;	/* This is used to avoid multiplication etc
-			 * when there is only the value '1' in the
-			 * buffer. */
-	wvalue=0;	/* The 'value' of the window */
-	wstart=bits-1;	/* The top bit of the window */
-	wend=0;		/* The bottom bit of the window */
-
-	if (!BN_one(r)) goto err;
-
-	for (;;)
-		{
-		if (BN_is_bit_set(p,wstart) == 0)
-			{
-			if (!start)
-				if (!BN_mod_mul(r,r,r,m,ctx))
-				goto err;
-			if (wstart == 0) break;
-			wstart--;
-			continue;
-			}
-		/* We now have wstart on a 'set' bit, we now need to work out
-		 * how bit a window to do.  To do this we need to scan
-		 * forward until the last set bit before the end of the
-		 * window */
-		j=wstart;
-		wvalue=1;
-		wend=0;
-		for (i=1; i<window; i++)
-			{
-			if (wstart-i < 0) break;
-			if (BN_is_bit_set(p,wstart-i))
-				{
-				wvalue<<=(i-wend);
-				wvalue|=1;
-				wend=i;
-				}
-			}
-
-		/* wend is the size of the current window */
-		j=wend+1;
-		/* add the 'bytes above' */
-		if (!start)
-			for (i=0; i<j; i++)
-				{
-				if (!BN_mod_mul(r,r,r,m,ctx))
-					goto err;
-				}
-		
-		/* wvalue will be an odd number < 2^window */
-		if (!BN_mod_mul(r,r,val[wvalue>>1],m,ctx))
-			goto err;
-
-		/* move the 'window' down further */
-		wstart-=wend+1;
-		wvalue=0;
-		start=0;
-		if (wstart < 0) break;
-		}
-	ret=1;
-err:
-	BN_CTX_end(ctx);
-	bn_check_top(r);
-	return(ret);
-	}
+                      const BIGNUM *m, BN_CTX *ctx)
+{
+    int i, j, bits, ret = 0, wstart, wend, window, wvalue;
+    int start = 1;
+    BIGNUM *d;
+    /* Table of variables obtained from 'ctx' */
+    BIGNUM *val[TABLE_SIZE];
+
+    if (BN_get_flags(p, BN_FLG_CONSTTIME) != 0) {
+        /* BN_FLG_CONSTTIME only supported by BN_mod_exp_mont() */
+        BNerr(BN_F_BN_MOD_EXP_SIMPLE, ERR_R_SHOULD_NOT_HAVE_BEEN_CALLED);
+        return -1;
+    }
+
+    bits = BN_num_bits(p);
+
+    if (bits == 0) {
+        ret = BN_one(r);
+        return ret;
+    }
+
+    BN_CTX_start(ctx);
+    d = BN_CTX_get(ctx);
+    val[0] = BN_CTX_get(ctx);
+    if (!d || !val[0])
+        goto err;
+
+    if (!BN_nnmod(val[0], a, m, ctx))
+        goto err;               /* 1 */
+    if (BN_is_zero(val[0])) {
+        BN_zero(r);
+        ret = 1;
+        goto err;
+    }
+
+    window = BN_window_bits_for_exponent_size(bits);
+    if (window > 1) {
+        if (!BN_mod_mul(d, val[0], val[0], m, ctx))
+            goto err;           /* 2 */
+        j = 1 << (window - 1);
+        for (i = 1; i < j; i++) {
+            if (((val[i] = BN_CTX_get(ctx)) == NULL) ||
+                !BN_mod_mul(val[i], val[i - 1], d, m, ctx))
+                goto err;
+        }
+    }
+
+    start = 1;                  /* This is used to avoid multiplication etc
+                                 * when there is only the value '1' in the
+                                 * buffer. */
+    wvalue = 0;                 /* The 'value' of the window */
+    wstart = bits - 1;          /* The top bit of the window */
+    wend = 0;                   /* The bottom bit of the window */
+
+    if (!BN_one(r))
+        goto err;
+
+    for (;;) {
+        if (BN_is_bit_set(p, wstart) == 0) {
+            if (!start)
+                if (!BN_mod_mul(r, r, r, m, ctx))
+                    goto err;
+            if (wstart == 0)
+                break;
+            wstart--;
+            continue;
+        }
+        /*
+         * We now have wstart on a 'set' bit, we now need to work out how bit
+         * a window to do.  To do this we need to scan forward until the last
+         * set bit before the end of the window
+         */
+        j = wstart;
+        wvalue = 1;
+        wend = 0;
+        for (i = 1; i < window; i++) {
+            if (wstart - i < 0)
+                break;
+            if (BN_is_bit_set(p, wstart - i)) {
+                wvalue <<= (i - wend);
+                wvalue |= 1;
+                wend = i;
+            }
+        }
+
+        /* wend is the size of the current window */
+        j = wend + 1;
+        /* add the 'bytes above' */
+        if (!start)
+            for (i = 0; i < j; i++) {
+                if (!BN_mod_mul(r, r, r, m, ctx))
+                    goto err;
+            }
+
+        /* wvalue will be an odd number < 2^window */
+        if (!BN_mod_mul(r, r, val[wvalue >> 1], m, ctx))
+            goto err;
+
+        /* move the 'window' down further */
+        wstart -= wend + 1;
+        wvalue = 0;
+        start = 0;
+        if (wstart < 0)
+            break;
+    }
+    ret = 1;
+ err:
+    BN_CTX_end(ctx);
+    bn_check_top(r);
+    return (ret);
+}