Use MONT_WORD macro to control if the word-based or the bignum (6535eb17) · Commits · CYBER - Cyber Security / TS 103 523 MSP / TLMSP / TLMSP OpenSSL

crypto/bn/bn.h

+0 −1

Original line number	Diff line number	Diff line
		@@ -260,7 +260,6 @@ typedef struct bn_blinding_st
		/* Used for montgomery multiplication */
		typedef struct bn_mont_ctx_st
		{
		int use_word; /* 0 for word form, 1 for bignum form */
		int ri; /* number of bits in R */
		BIGNUM RR; /* used to convert to montgomery form */
		BIGNUM N; /* The modulus */

crypto/bn/bn_mont.c

+95 −114

Original line number	Diff line number	Diff line
		@@ -67,6 +67,8 @@
		#include "cryptlib.h"
		#include "bn_lcl.h"

		#define MONT_WORD /* use the faster word-based algorithm */

		int BN_mod_mul_montgomery(BIGNUM r, BIGNUM a, BIGNUM *b,
		BN_MONT_CTX mont, BN_CTX ctx)
		{
		@@ -105,22 +107,17 @@ err:
		return(0);
		}

		#define BN_RECURSION_MONT

		int BN_from_montgomery(BIGNUM ret, BIGNUM a, BN_MONT_CTX *mont,
		BN_CTX *ctx)
		{
		int retn=0;
		BN_CTX_start(ctx);

		#ifdef BN_RECURSION_MONT
		if (mont->use_word)
		#endif
		{
		#ifdef MONT_WORD
		BIGNUM n,r;
		BN_ULONG ap,np,rp,n0,v,nrp;
		int al,nl,max,i,x,ri;

		BN_CTX_start(ctx);
		if ((r = BN_CTX_get(ctx)) == NULL) goto err;

		if (!BN_copy(r,a)) goto err;
		@@ -203,18 +200,10 @@ printf("word BN_from_montgomery %d * %d\n",nl,nl);
		for (; i<al; i++)
		rp[i]=ap[i];
		#endif

		if (BN_ucmp(ret, &(mont->N)) >= 0)
		{
		BN_usub(ret,ret,&(mont->N)); /* XXX */
		}
		retn=1;
		}
		#ifdef BN_RECURSION_MONT
		else /* bignum version */
		{
		#else /* !MONT_WORD */
		BIGNUM t1,t2;

		BN_CTX_start(ctx);
		t1 = BN_CTX_get(ctx);
		t2 = BN_CTX_get(ctx);
		if (t1 == NULL \|\| t2 == NULL) goto err;
		@@ -228,12 +217,13 @@ printf("word BN_from_montgomery %d * %d\n",nl,nl);
		if (!BN_mul(t1,t2,&mont->N,ctx)) goto err;
		if (!BN_add(t2,a,t1)) goto err;
		BN_rshift(ret,t2,mont->ri);
		#endif /* MONT_WORD */

		if (BN_ucmp(ret,&mont->N) >= 0)
		BN_usub(ret,ret,&mont->N);
		retn=1;
		if (BN_ucmp(ret, &(mont->N)) >= 0)
		{
		BN_usub(ret,ret,&(mont->N));
		}
		#endif
		retn=1;
		err:
		BN_CTX_end(ctx);
		return(retn);
		@@ -253,7 +243,6 @@ BN_MONT_CTX *BN_MONT_CTX_new(void)

		void BN_MONT_CTX_init(BN_MONT_CTX *ctx)
		{
		ctx->use_word=0;
		ctx->ri=0;
		BN_init(&(ctx->RR));
		BN_init(&(ctx->N));
		@@ -281,16 +270,11 @@ int BN_MONT_CTX_set(BN_MONT_CTX mont, const BIGNUM mod, BN_CTX *ctx)
		R= &(mont->RR); /* grab RR as a temp */
		BN_copy(&(mont->N),mod); /* Set N */

		#ifdef BN_RECURSION_MONT
		/* the word-based algorithm is faster */
		if (mont->N.top > BN_MONT_CTX_SET_SIZE_WORD)
		#endif
		#ifdef MONT_WORD
		{
		BIGNUM tmod;
		BN_ULONG buf[2];

		mont->use_word=1;

		mont->ri=(BN_num_bits(mod)+(BN_BITS2-1))/BN_BITS2*BN_BITS2;
		BN_zero(R);
		BN_set_bit(R,BN_BITS2); /* R */
		@@ -314,10 +298,8 @@ int BN_MONT_CTX_set(BN_MONT_CTX mont, const BIGNUM mod, BN_CTX *ctx)
		mont->n0=Ri.d[0];
		BN_free(&Ri);
		}
		#ifdef BN_RECURSION_MONT
		else
		#else /* !MONT_WORD */
		{ /* bignum version */
		mont->use_word=0;
		mont->ri=BN_num_bits(mod);
		BN_zero(R);
		BN_set_bit(R,mont->ri); /* R = 2^ri */
		@@ -349,7 +331,6 @@ BN_MONT_CTX BN_MONT_CTX_copy(BN_MONT_CTX to, BN_MONT_CTX *from)
		BN_copy(&(to->RR),&(from->RR));
		BN_copy(&(to->N),&(from->N));
		BN_copy(&(to->Ni),&(from->Ni));
		to->use_word=from->use_word;
		to->ri=from->ri;
		to->n0=from->n0;
		return(to);

doc/crypto/BN_mod_mul_montgomery.pod

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Original line number	Diff line number	Diff line
		@@ -58,7 +58,6 @@ The B<BN_MONT_CTX> structure is defined as follows:

		typedef struct bn_mont_ctx_st
		{
		int use_word; /* 0 for word form, 1 for bignum form */
		int ri; /* number of bits in R */
		BIGNUM RR; /* R^2 (used to convert to Montgomery form) */
		BIGNUM N; /* The modulus */