Convert openssl code not to assume the deprecated form of BN_zero().

Remove certain redundant BN_zero() initialisations, because BN_CTX_get(),
BN_init(), [etc] already initialise to zero.

Correct error checking in bn_sqr.c, and be less wishy-wash about how/why
the result's 'top' value is set (note also, 'max' is always > 0 at this
point).

diff --git a/CHANGES b/CHANGES
index e675c90309ce6281d5cc66b841ef5cd6c14588cd..a8866ad9a03d35d4fbd7566f3dbcd398b3f862f9 100644 (file)
--- a/CHANGES
+++ b/CHANGES
@@ -4,6 +4,12 @@
 
  Changes between 0.9.7c and 0.9.8  [xx XXX xxxx]
 
+  *) BN_zero() only needs to set 'top' and 'neg' to zero for correct results,
+     and this should never fail. So the return value from the use of
+     BN_set_word() (which can fail due to needless expansion) is now deprecated;
+     if OPENSSL_NO_DEPRECATED is defined, BN_zero() is a void macro.
+     [Geoff Thorpe]
+
   *) BN_CTX_get() should return zero-valued bignums, providing the same
      initialised value as BN_new().
      [Geoff Thorpe, suggested by Ulf Möller]

diff --git a/crypto/bn/bn_exp.c b/crypto/bn/bn_exp.c
index aef77cb792692e1360a1a42fd495f82aeb4e835d..c11e5afd3288fc82b72e656385cdf07c7832c315 100644 (file)
--- a/crypto/bn/bn_exp.c
+++ b/crypto/bn/bn_exp.c
@@ -266,7 +266,8 @@ int BN_mod_exp_recp(BIGNUM *r, const BIGNUM *a, const BIGNUM *p,
        if (!BN_nnmod(&(val[0]),a,m,ctx)) goto err;             /* 1 */
        if (BN_is_zero(&(val[0])))
                {
-               ret = BN_zero(r);
+               BN_zero(r);
+               ret = 1;
                goto err;
                }
 
@@ -409,7 +410,8 @@ int BN_mod_exp_mont(BIGNUM *rr, const BIGNUM *a, const BIGNUM *p,
                aa=a;
        if (BN_is_zero(aa))
                {
-               ret = BN_zero(rr);
+               BN_zero(rr);
+               ret = 1;
                goto err;
                }
        if (!BN_to_montgomery(&(val[0]),aa,mont,ctx)) goto err; /* 1 */
@@ -541,7 +543,8 @@ int BN_mod_exp_mont_word(BIGNUM *rr, BN_ULONG a, const BIGNUM *p,
                }
        if (a == 0)
                {
-               ret = BN_zero(rr);
+               BN_zero(rr);
+               ret = 1;
                return ret;
                }
 
@@ -666,7 +669,8 @@ int BN_mod_exp_simple(BIGNUM *r, const BIGNUM *a, const BIGNUM *p,
        if (!BN_nnmod(&(val[0]),a,m,ctx)) goto err;             /* 1 */
        if (BN_is_zero(&(val[0])))
                {
-               ret = BN_zero(r);
+               BN_zero(r);
+               ret = 1;
                goto err;
                }
 

diff --git a/crypto/bn/bn_exp2.c b/crypto/bn/bn_exp2.c
index 979ceeffce8cbc21f990c7f89d25c614fed9ffe3..1223c678ce3d4bb04e07a706f327212367ac3b08 100644 (file)
--- a/crypto/bn/bn_exp2.c
+++ b/crypto/bn/bn_exp2.c
@@ -179,7 +179,8 @@ int BN_mod_exp2_mont(BIGNUM *rr, const BIGNUM *a1, const BIGNUM *p1,
                a_mod_m = a1;
        if (BN_is_zero(a_mod_m))
                {
-               ret = BN_zero(rr);
+               BN_zero(rr);
+               ret = 1;
                goto err;
                }
 
@@ -214,7 +215,8 @@ int BN_mod_exp2_mont(BIGNUM *rr, const BIGNUM *a1, const BIGNUM *p1,
                a_mod_m = a2;
        if (BN_is_zero(a_mod_m))
                {
-               ret = BN_zero(rr);
+               BN_zero(rr);
+               ret = 1;
                goto err;
                }
        if (!BN_to_montgomery(&(val2[0]),a_mod_m,mont,ctx)) goto err;

diff --git a/crypto/bn/bn_gf2m.c b/crypto/bn/bn_gf2m.c
index 30520eedecdca03aebaf63506a33392c61957d67..17513b116639bfc38822d0b56dc798c756e7d319 100644 (file)
--- a/crypto/bn/bn_gf2m.c
+++ b/crypto/bn/bn_gf2m.c
@@ -329,8 +329,11 @@ int BN_GF2m_mod_arr(BIGNUM *r, const BIGNUM *a, const unsigned int p[])
        bn_check_top(a);
 
        if (!p[0])
+               {
                /* reduction mod 1 => return 0 */
-               return BN_zero(r);
+               BN_zero(r);
+               return 1;
+               }
 
        /* Since the algorithm does reduction in the r value, if a != r, copy
         * the contents of a into r so we can do reduction in r. 
@@ -590,7 +593,6 @@ int BN_GF2m_mod_inv(BIGNUM *r, const BIGNUM *a, const BIGNUM *p, BN_CTX *ctx)
        if (v == NULL) goto err;
 
        if (!BN_one(b)) goto err;
-       if (!BN_zero(c)) goto err;
        if (!BN_GF2m_mod(u, a, p)) goto err;
        if (!BN_copy(v, p)) goto err;
 
@@ -709,7 +711,6 @@ int BN_GF2m_mod_div(BIGNUM *r, const BIGNUM *y, const BIGNUM *x, const BIGNUM *p
        if (!BN_GF2m_mod(u, y, p)) goto err;
        if (!BN_GF2m_mod(a, x, p)) goto err;
        if (!BN_copy(b, p)) goto err;
-       if (!BN_zero(v)) goto err;
        
        while (!BN_is_odd(a))
                {
@@ -865,13 +866,15 @@ int       BN_GF2m_mod_sqrt_arr(BIGNUM *r, const BIGNUM *a, const unsigned int p[], BN_
        bn_check_top(a);
 
        if (!p[0])
+               {
                /* reduction mod 1 => return 0 */
-               return BN_zero(r);
+               BN_zero(r);
+               return 1;
+               }
 
        BN_CTX_start(ctx);
        if ((u = BN_CTX_get(ctx)) == NULL) goto err;
        
-       if (!BN_zero(u)) goto err;
        if (!BN_set_bit(u, p[0] - 1)) goto err;
        ret = BN_GF2m_mod_exp_arr(r, a, u, p, ctx);
        bn_check_top(r);
@@ -921,8 +924,11 @@ int BN_GF2m_mod_solve_quad_arr(BIGNUM *r, const BIGNUM *a_, const unsigned int p
        bn_check_top(a_);
 
        if (!p[0])
+               {
                /* reduction mod 1 => return 0 */
-               return BN_zero(r);
+               BN_zero(r);
+               return 1;
+               }
 
        BN_CTX_start(ctx);
        a = BN_CTX_get(ctx);
@@ -934,7 +940,8 @@ int BN_GF2m_mod_solve_quad_arr(BIGNUM *r, const BIGNUM *a_, const unsigned int p
        
        if (BN_is_zero(a))
                {
-               ret = BN_zero(r);
+               BN_zero(r);
+               ret = 1;
                goto err;
                }
 
@@ -960,7 +967,7 @@ int BN_GF2m_mod_solve_quad_arr(BIGNUM *r, const BIGNUM *a_, const unsigned int p
                        {
                        if (!BN_rand(rho, p[0], 0, 0)) goto err;
                        if (!BN_GF2m_mod_arr(rho, rho, p)) goto err;
-                       if (!BN_zero(z)) goto err;
+                       BN_zero(z);
                        if (!BN_copy(w, rho)) goto err;
                        for (j = 1; j <= p[0] - 1; j++)
                                {

diff --git a/crypto/bn/bn_mont.c b/crypto/bn/bn_mont.c
index 22d23cc3d73635e892b2220692550dc93f53ca4f..14650ab9d5a4e2c8c77898ae12fccb9d066006cc 100644 (file)
--- a/crypto/bn/bn_mont.c
+++ b/crypto/bn/bn_mont.c
@@ -284,7 +284,7 @@ int BN_MONT_CTX_set(BN_MONT_CTX *mont, const BIGNUM *mod, BN_CTX *ctx)
                BN_ULONG buf[2];
 
                mont->ri=(BN_num_bits(mod)+(BN_BITS2-1))/BN_BITS2*BN_BITS2;
-               if (!(BN_zero(R))) goto err;
+               BN_zero(R);
                if (!(BN_set_bit(R,BN_BITS2))) goto err;        /* R */
 
                buf[0]=mod->d[0]; /* tmod = N mod word size */
@@ -314,7 +314,7 @@ int BN_MONT_CTX_set(BN_MONT_CTX *mont, const BIGNUM *mod, BN_CTX *ctx)
 #else /* !MONT_WORD */
                { /* bignum version */
                mont->ri=BN_num_bits(&mont->N);
-               if (!BN_zero(R)) goto err;
+               BN_zero(R);
                if (!BN_set_bit(R,mont->ri)) goto err;  /* R = 2^ri */
                                                        /* Ri = R^-1 mod N*/
                if ((BN_mod_inverse(&Ri,R,&mont->N,ctx)) == NULL)
@@ -328,7 +328,7 @@ int BN_MONT_CTX_set(BN_MONT_CTX *mont, const BIGNUM *mod, BN_CTX *ctx)
 #endif
 
        /* setup RR for conversions */
-       if (!BN_zero(&(mont->RR))) goto err;
+       BN_zero(&(mont->RR));
        if (!BN_set_bit(&(mont->RR),mont->ri*2)) goto err;
        if (!BN_mod(&(mont->RR),&(mont->RR),&(mont->N),ctx)) goto err;
 

diff --git a/crypto/bn/bn_mul.c b/crypto/bn/bn_mul.c
index 5a92f9a335c76b333bbc333930029da9a7bbcbcc..aec1eafc65fbb25a8fbeda30f8f6025129a3c716 100644 (file)
--- a/crypto/bn/bn_mul.c
+++ b/crypto/bn/bn_mul.c
@@ -964,7 +964,7 @@ int BN_mul(BIGNUM *r, const BIGNUM *a, const BIGNUM *b, BN_CTX *ctx)
 
        if ((al == 0) || (bl == 0))
                {
-               if (!BN_zero(r)) goto err;
+               BN_zero(r);
                return(1);
                }
        top=al+bl;
@@ -1094,8 +1094,8 @@ end:
        if (r != rr) BN_copy(r,rr);
        ret=1;
 err:
-       BN_CTX_end(ctx);
        bn_check_top(r);
+       BN_CTX_end(ctx);
        return(ret);
        }
 

diff --git a/crypto/bn/bn_nist.c b/crypto/bn/bn_nist.c
index a29503be25e9ae47c3a167a2c6e77acd7193a4e7..bbe2cbe74971fa7655ad6e4c9f1ebe061e58777f 100644 (file)
--- a/crypto/bn/bn_nist.c
+++ b/crypto/bn/bn_nist.c
@@ -319,7 +319,10 @@ int BN_nist_mod_192(BIGNUM *r, const BIGNUM *a, const BIGNUM *field,
 
        top = BN_ucmp(field, a);
        if (top == 0)
-               return BN_zero(r);
+               {
+               BN_zero(r);
+               return 1;
+               }
        else if (top > 0)
                return (r == a)? 1 : (BN_copy(r ,a) != NULL);
 
@@ -394,7 +397,10 @@ int BN_nist_mod_224(BIGNUM *r, const BIGNUM *a, const BIGNUM *field,
 
        tmp_int = BN_ucmp(field, a);
        if (tmp_int == 0)
-               return BN_zero(r);
+               {
+               BN_zero(r);
+               return 1;
+               }
        else if (tmp_int > 0)
                return (r == a)? 1 : (BN_copy(r ,a) != NULL);
 
@@ -514,7 +520,10 @@ int BN_nist_mod_256(BIGNUM *r, const BIGNUM *a, const BIGNUM *field,
        
        tmp_int = BN_ucmp(field, a);
        if (tmp_int == 0)
-               return BN_zero(r);
+               {
+               BN_zero(r);
+               return 1;
+               }
        else if (tmp_int > 0)
                return (r == a)? 1 : (BN_copy(r ,a) != NULL);
 
@@ -672,7 +681,10 @@ int BN_nist_mod_384(BIGNUM *r, const BIGNUM *a, const BIGNUM *field,
 
        tmp_int = BN_ucmp(field, a);
        if (tmp_int == 0)
-               return BN_zero(r);
+               {
+               BN_zero(r);
+               return 1;
+               }
        else if (tmp_int > 0)
                return (r == a)? 1 : (BN_copy(r ,a) != NULL);
 

diff --git a/crypto/bn/bn_rand.c b/crypto/bn/bn_rand.c
index de5a1f0c6317242cb44cf87cd6d53f6ec129a0b6..df45575f9a7d0142683fd8c56dbe01fbdab22f31 100644 (file)
--- a/crypto/bn/bn_rand.c
+++ b/crypto/bn/bn_rand.c
@@ -244,9 +244,7 @@ static int bn_rand_range(int pseudo, BIGNUM *r, BIGNUM *range)
        /* BN_is_bit_set(range, n - 1) always holds */
 
        if (n == 1)
-               {
-               if (!BN_zero(r)) return 0;
-               }
+               BN_zero(r);
        else if (!BN_is_bit_set(range, n - 2) && !BN_is_bit_set(range, n - 3))
                {
                /* range = 100..._2,

diff --git a/crypto/bn/bn_recp.c b/crypto/bn/bn_recp.c
index 411dd608956f2ffdf040356e2d124445b9c46240..05b845b2a19f0df8e9ded38189ecef49568f71db 100644 (file)
--- a/crypto/bn/bn_recp.c
+++ b/crypto/bn/bn_recp.c
@@ -94,7 +94,7 @@ void BN_RECP_CTX_free(BN_RECP_CTX *recp)
 int BN_RECP_CTX_set(BN_RECP_CTX *recp, const BIGNUM *d, BN_CTX *ctx)
        {
        if (!BN_copy(&(recp->N),d)) return 0;
-       if (!BN_zero(&(recp->Nr))) return 0;
+       BN_zero(&(recp->Nr));
        recp->num_bits=BN_num_bits(d);
        recp->shift=0;
        return(1);
@@ -148,7 +148,7 @@ int BN_div_recp(BIGNUM *dv, BIGNUM *rem, const BIGNUM *m,
 
        if (BN_ucmp(m,&(recp->N)) < 0)
                {
-               if (!BN_zero(d)) return 0;
+               BN_zero(d);
                if (!BN_copy(r,m)) return 0;
                BN_CTX_end(ctx);
                return(1);
@@ -221,7 +221,6 @@ int BN_reciprocal(BIGNUM *r, const BIGNUM *m, int len, BN_CTX *ctx)
 
        BN_init(&t);
 
-       if (!BN_zero(&t)) goto err;
        if (!BN_set_bit(&t,len)) goto err;
 
        if (!BN_div(r,NULL,&t,m,ctx)) goto err;

diff --git a/crypto/bn/bn_sqr.c b/crypto/bn/bn_sqr.c
index ab678d1f30f52ad805f92eaafe62777724abba58..8831daa390a7be5cdbb0bc7815cfb6ebe0efb6b1 100644 (file)
--- a/crypto/bn/bn_sqr.c
+++ b/crypto/bn/bn_sqr.c
@@ -77,15 +77,15 @@ int BN_sqr(BIGNUM *r, const BIGNUM *a, BN_CTX *ctx)
        if (al <= 0)
                {
                r->top=0;
-               return(1);
+               return 1;
                }
 
        BN_CTX_start(ctx);
        rr=(a != r) ? r : BN_CTX_get(ctx);
        tmp=BN_CTX_get(ctx);
-       if (tmp == NULL) goto err;
+       if (!rr || !tmp) goto err;
 
-       max=(al+al);
+       max = 2 * al; /* Non-zero (from above) */
        if (bn_wexpand(rr,max+1) == NULL) goto err;
 
        if (al == 4)
@@ -138,14 +138,19 @@ int BN_sqr(BIGNUM *r, const BIGNUM *a, BN_CTX *ctx)
 #endif
                }
 
-       rr->top=max;
        rr->neg=0;
-       if ((max > 0) && (rr->d[max-1] == 0)) rr->top--;
+       /* If the most-significant half of the top word of 'a' is zero, then
+        * the square of 'a' will max-1 words. */
+       if(a->d[al - 1] == (a->d[al - 1] & BN_MASK2l))
+               rr->top = max - 1;
+       else
+               rr->top = max;
        if (rr != r) BN_copy(r,rr);
        ret = 1;
  err:
+       if(rr) bn_check_top(rr);
+       if(tmp) bn_check_top(tmp);
        BN_CTX_end(ctx);
-       bn_check_top(r);
        return(ret);
        }
 

diff --git a/crypto/bn/bn_sqrt.c b/crypto/bn/bn_sqrt.c
index 51902703e1ed1e8b4ba3e8d621894079feeeacd7..924ee274dfc7ddb047dd066269c673e827a5965c 100644 (file)
--- a/crypto/bn/bn_sqrt.c
+++ b/crypto/bn/bn_sqrt.c
@@ -288,7 +288,7 @@ BIGNUM *BN_mod_sqrt(BIGNUM *in, const BIGNUM *a, const BIGNUM *p, BN_CTX *ctx)
                if (BN_is_zero(t))
                        {
                        /* special case: a == 0  (mod p) */
-                       if (!BN_zero(ret)) goto end;
+                       BN_zero(ret);
                        err = 0;
                        goto end;
                        }
@@ -301,7 +301,7 @@ BIGNUM *BN_mod_sqrt(BIGNUM *in, const BIGNUM *a, const BIGNUM *p, BN_CTX *ctx)
                if (BN_is_zero(x))
                        {
                        /* special case: a == 0  (mod p) */
-                       if (!BN_zero(ret)) goto end;
+                       BN_zero(ret);
                        err = 0;
                        goto end;
                        }

diff --git a/crypto/ec/ec2_mult.c b/crypto/ec/ec2_mult.c
index a0ee7c152ff6d11eefba780ac055ca938c731e9b..a8ead01d610d1d0fb717f8cbdac9b44d9269206a 100644 (file)
--- a/crypto/ec/ec2_mult.c
+++ b/crypto/ec/ec2_mult.c
@@ -155,8 +155,8 @@ static int gf2m_Mxy(const EC_GROUP *group, const BIGNUM *x, const BIGNUM *y, BIG
        
        if (BN_is_zero(z1))
                {
-               if (!BN_zero(x2)) return 0;
-               if (!BN_zero(z2)) return 0;
+               BN_zero(x2);
+               BN_zero(z2);
                return 1;
                }
        

diff --git a/crypto/ec/ec2_smpl.c b/crypto/ec/ec2_smpl.c
index 89e81520150062179d95ed126826d5dae6f3b954..1132c8e5afa828333202066c3d0309a583504b0e 100644 (file)
--- a/crypto/ec/ec2_smpl.c
+++ b/crypto/ec/ec2_smpl.c
@@ -335,7 +335,8 @@ int ec_GF2m_simple_point_copy(EC_POINT *dest, const EC_POINT *src)
 int ec_GF2m_simple_point_set_to_infinity(const EC_GROUP *group, EC_POINT *point)
        {
        point->Z_is_one = 0;
-       return (BN_zero(&point->Z));
+       BN_zero(&point->Z);
+       return 1;
        }
 
 

diff --git a/crypto/ec/ec_lib.c b/crypto/ec/ec_lib.c
index b3ef05659ada196f0213ff1c4dcd7777e5a9429f..ba5b821c9c88955895e24689ca41ff199360a54a 100644 (file)
--- a/crypto/ec/ec_lib.c
+++ b/crypto/ec/ec_lib.c
@@ -299,12 +299,12 @@ int EC_GROUP_set_generator(EC_GROUP *group, const EC_POINT *generator, const BIG
        if (order != NULL)
                { if (!BN_copy(&group->order, order)) return 0; }       
        else
-               { if (!BN_zero(&group->order)) return 0; }      
+               BN_zero(&group->order);
 
        if (cofactor != NULL)
                { if (!BN_copy(&group->cofactor, cofactor)) return 0; } 
        else
-               { if (!BN_zero(&group->cofactor)) return 0; }   
+               BN_zero(&group->cofactor);
 
        return 1;
        }

diff --git a/crypto/ec/ecp_smpl.c b/crypto/ec/ecp_smpl.c
index 1abe831a375e063fdbda9e0eba59e49c601221eb..de90f90aa10defb62c9f69cc5a889d3421fa2048 100644 (file)
--- a/crypto/ec/ecp_smpl.c
+++ b/crypto/ec/ecp_smpl.c
@@ -385,7 +385,8 @@ int ec_GFp_simple_point_copy(EC_POINT *dest, const EC_POINT *src)
 int ec_GFp_simple_point_set_to_infinity(const EC_GROUP *group, EC_POINT *point)
        {
        point->Z_is_one = 0;
-       return (BN_zero(&point->Z));
+       BN_zero(&point->Z);
+       return 1;
        }
 
 
@@ -1093,7 +1094,7 @@ int ec_GFp_simple_add(const EC_GROUP *group, EC_POINT *r, const EC_POINT *a, con
                else
                        {
                        /* a is the inverse of b */
-                       if (!BN_zero(&r->Z)) goto end;
+                       BN_zero(&r->Z);
                        r->Z_is_one = 0;
                        ret = 1;
                        goto end;
@@ -1169,7 +1170,7 @@ int ec_GFp_simple_dbl(const EC_GROUP *group, EC_POINT *r, const EC_POINT *a, BN_
        
        if (EC_POINT_is_at_infinity(group, a))
                {
-               if (!BN_zero(&r->Z)) return 0;
+               BN_zero(&r->Z);
                r->Z_is_one = 0;
                return 1;
                }