Commit 2bfd2c74 authored by Geoff Thorpe's avatar Geoff Thorpe
Browse files

Incremental cleanups to bn_lib.c. 

- Add missing bn_check_top() calls and relocate some others
- Use BN_is_zero() where appropriate
- Remove assert()s that bn_check_top() is already covering
- Simplify the code in places (esp. bn_expand2())
- Only keep ambiguous zero handling if BN_STRICT isn't defined
- Remove some white-space and make some other aesthetic tweaks
parent 82b2f57e

crypto/bn/bn_lib.c

+38 −48
Original line number Diff line number Diff line
@@ -244,16 +244,11 @@ int BN_num_bits_word(BN_ULONG l) 


int BN_num_bits(const BIGNUM *a)

	{

	BN_ULONG l;

	int i;



	int i = a->top - 1;

	bn_check_top(a);



	if (a->top == 0) return(0);

	l=a->d[a->top-1];

	assert(l != 0);

	i=(a->top-1)*BN_BITS2;

	return(i+BN_num_bits_word(l));

	if (BN_is_zero(a)) return 0;

	return ((i*BN_BITS2) + BN_num_bits_word(a->d[i]));

	}



void BN_clear_free(BIGNUM *a)
@@ -261,6 +256,7 @@ void BN_clear_free(BIGNUM *a) 
	int i;



	if (a == NULL) return;

	bn_check_top(a);

	if (a->d != NULL)

		{

		OPENSSL_cleanse(a->d,a->dmax*sizeof(a->d[0]));
@@ -276,6 +272,7 @@ void BN_clear_free(BIGNUM *a) 
void BN_free(BIGNUM *a)

	{

	if (a == NULL) return;

	bn_check_top(a);

	if ((a->d != NULL) && !(BN_get_flags(a,BN_FLG_STATIC_DATA)))

		OPENSSL_free(a->d);

	if (a->flags & BN_FLG_MALLOCED)
@@ -321,13 +318,13 @@ static BN_ULONG *bn_expand_internal(const BIGNUM *b, int words) 
	const BN_ULONG *B;

	int i;



	bn_check_top(b);



	if (words > (INT_MAX/(4*BN_BITS2)))

		{

		BNerr(BN_F_BN_EXPAND_INTERNAL,BN_R_BIGNUM_TOO_LONG);

		return NULL;

		}



	bn_check_top(b);	

	if (BN_get_flags(b,BN_FLG_STATIC_DATA))

		{

		BNerr(BN_F_BN_EXPAND_INTERNAL,BN_R_EXPAND_ON_STATIC_BIGNUM_DATA);
@@ -394,6 +391,8 @@ BIGNUM *bn_dup_expand(const BIGNUM *b, int words) 
	{

	BIGNUM *r = NULL;



	bn_check_top(b);



	/* This function does not work if

	 *      words <= b->dmax && top < words

	 * because BN_dup() does not preserve 'dmax'!
@@ -443,23 +442,19 @@ BIGNUM *bn_expand2(BIGNUM *b, int words) 
	BN_ULONG *A;

	int i;



	bn_check_top(b);



	if (words > b->dmax)

		{

		BN_ULONG *a = bn_expand_internal(b, words);



		if (a)

			{

			if (b->d)

				OPENSSL_free(b->d);

		if(!a) return NULL;

		if(b->d) OPENSSL_free(b->d);

		b->d=a;

		b->dmax=words;

		}

		else

			b = NULL;

		}



	/* NB: bn_wexpand() calls this only if the BIGNUM really has to grow */

	if ((b != NULL) && (b->top < b->dmax))

	if (b->top < b->dmax)

		{

		A = &(b->d[b->top]);

		for (i=(b->dmax - b->top)>>3; i>0; i--,A+=8)
@@ -471,26 +466,26 @@ BIGNUM *bn_expand2(BIGNUM *b, int words) 
			A[0]=0;

		assert(A == &(b->d[b->dmax]));

		}

	else if(b) bn_check_top(b);

	bn_check_top(b);

	return b;

	}



BIGNUM *BN_dup(const BIGNUM *a)

	{

	BIGNUM *r, *t;

	BIGNUM *t;



	if (a == NULL) return NULL;



	bn_check_top(a);



	t = BN_new();

	if (t == NULL) return(NULL);

	r = BN_copy(t, a);

	/* now  r == t || r == NULL */

	if (r == NULL)

	if (t == NULL) return NULL;

	if(!BN_copy(t, a))

		{

		BN_free(t);

	bn_check_top(r);

	return r;

		return NULL;

		}

	bn_check_top(t);

	return t;

	}



BIGNUM *BN_copy(BIGNUM *a, const BIGNUM *b)
@@ -524,10 +519,11 @@ BIGNUM *BN_copy(BIGNUM *a, const BIGNUM *b) 
	memcpy(a->d,b->d,sizeof(b->d[0])*b->top);

#endif



/*	memset(&(a->d[b->top]),0,sizeof(a->d[0])*(a->max-b->top));*/

	a->top=b->top;

#ifndef BN_STRICT

	if ((a->top == 0) && (a->d != NULL))

		a->d[0]=0;

#endif

	a->neg=b->neg;

	bn_check_top(a);

	return(a);
@@ -540,18 +536,15 @@ BIGNUM *BN_ncopy(BIGNUM *a, const BIGNUM *b, size_t n) 
	const BN_ULONG *B;



	bn_check_top(b);



	if (a == b)

		return a;



	min = (b->top < (int)n)? b->top: (int)n;



	if (!min)

		{

		BN_zero(a);

		return a;

		}



	if (bn_wexpand(a, min) == NULL)

		return NULL;
@@ -571,11 +564,8 @@ BIGNUM *BN_ncopy(BIGNUM *a, const BIGNUM *b, size_t n) 
		case 0: ;

		}

	a->top = min;



	a->neg = b->neg;

	bn_correct_top(a);



	bn_check_top(a);

	return(a);

	}
@@ -612,7 +602,6 @@ void BN_swap(BIGNUM *a, BIGNUM *b) 
	bn_check_top(b);

	}





void BN_clear(BIGNUM *a)

	{

	bn_check_top(a);
@@ -743,7 +732,7 @@ int BN_ucmp(const BIGNUM *a, const BIGNUM *b) 
		t1= ap[i];

		t2= bp[i];

		if (t1 != t2)

			return(t1 > t2?1:-1);

			return((t1 > t2) ? 1 : -1);

		}

	return(0);

	}
@@ -815,8 +804,8 @@ int BN_clear_bit(BIGNUM *a, int n) 
	{

	int i,j;



	if (n < 0)

		return 0;

	bn_check_top(a);

	if (n < 0) return 0;



	i=n/BN_BITS2;

	j=n%BN_BITS2;
@@ -831,10 +820,11 @@ int BN_is_bit_set(const BIGNUM *a, int n) 
	{

	int i,j;



	if (n < 0) return(0);

	bn_check_top(a);

	if (n < 0) return 0;

	i=n/BN_BITS2;

	j=n%BN_BITS2;

	if (a->top <= i) return(0);

	if (a->top <= i) return 0;

	return((a->d[i]&(((BN_ULONG)1)<<j))?1:0);

	}
@@ -842,12 +832,12 @@ int BN_mask_bits(BIGNUM *a, int n) 
	{

	int b,w;



	if (n < 0)

		return 0;

	bn_check_top(a);

	if (n < 0) return 0;



	w=n/BN_BITS2;

	b=n%BN_BITS2;

	if (w >= a->top) return(0);

	if (w >= a->top) return 0;

	if (b == 0)

		a->top=w;

	else