1 files changed, 103 insertions, 107 deletions

diff --git a/src/lib/libcrypto/bn/bn_exp.c b/src/lib/libcrypto/bn/bn_exp.c
index c056a5083f..2df1614ada 100644
--- a/src/lib/libcrypto/bn/bn_exp.c
+++ b/src/lib/libcrypto/bn/bn_exp.c
@@ -60,22 +60,23 @@
 #include "cryptlib.h"
 #include "bn_lcl.h"
 
+#define TABLE_SIZE      16
+
 /* slow but works */
-int BN_mod_mul(ret, a, b, m, ctx)
-BIGNUM *ret;
-BIGNUM *a;
-BIGNUM *b;
-BIGNUM *m;
-BN_CTX *ctx;
+int BN_mod_mul(BIGNUM *ret, BIGNUM *a, BIGNUM *b, const BIGNUM *m, BN_CTX *ctx)
         {
         BIGNUM *t;
         int r=0;
 
-        t=ctx->bn[ctx->tos++];
+        bn_check_top(a);
+        bn_check_top(b);
+        bn_check_top(m);
+
+        t= &(ctx->bn[ctx->tos++]);
         if (a == b)
                 { if (!BN_sqr(t,a,ctx)) goto err; }
         else
-                { if (!BN_mul(t,a,b)) goto err; }
+                { if (!BN_mul(t,a,b,ctx)) goto err; }
         if (!BN_mod(ret,t,m,ctx)) goto err;
         r=1;
 err:
@@ -85,22 +86,20 @@ err:
 
 #if 0
 /* this one works - simple but works */
-int BN_mod_exp(r,a,p,m,ctx)
-BIGNUM *r,*a,*p,*m;
-BN_CTX *ctx;
+int BN_mod_exp(BIGNUM *r, BIGNUM *a, BIGNUM *p, BIGNUM *m, BN_CTX *ctx)
         {
         int i,bits,ret=0;
         BIGNUM *v,*tmp;
 
-        v=ctx->bn[ctx->tos++];
-        tmp=ctx->bn[ctx->tos++];
+        v= &(ctx->bn[ctx->tos++]);
+        tmp= &(ctx->bn[ctx->tos++]);
 
         if (BN_copy(v,a) == NULL) goto err;
         bits=BN_num_bits(p);
 
         if (BN_is_odd(p))
                 { if (BN_copy(r,a) == NULL) goto err; }
-        else    { if (BN_one(r)) goto err; }
+        else    { if (!BN_one(r)) goto err; }
 
         for (i=1; i<bits; i++)
                 {
@@ -108,7 +107,7 @@ BN_CTX *ctx;
                 if (!BN_mod(v,tmp,m,ctx)) goto err;
                 if (BN_is_bit_set(p,i))
                         {
-                        if (!BN_mul(tmp,r,v)) goto err;
+                        if (!BN_mul(tmp,r,v,ctx)) goto err;
                         if (!BN_mod(r,tmp,m,ctx)) goto err;
                         }
                 }
@@ -121,46 +120,49 @@ err:
 #endif
 
 /* this one works - simple but works */
-int BN_exp(r,a,p,ctx)
-BIGNUM *r,*a,*p;
-BN_CTX *ctx;
+int BN_exp(BIGNUM *r, BIGNUM *a, BIGNUM *p, BN_CTX *ctx)
         {
-        int i,bits,ret=0;
-        BIGNUM *v,*tmp;
+        int i,bits,ret=0,tos;
+        BIGNUM *v,*rr;
 
-        v=ctx->bn[ctx->tos++];
-        tmp=ctx->bn[ctx->tos++];
+        tos=ctx->tos;
+        v= &(ctx->bn[ctx->tos++]);
+        if ((r == a) || (r == p))
+                rr= &(ctx->bn[ctx->tos++]);
+        else
+                rr=r;
 
         if (BN_copy(v,a) == NULL) goto err;
         bits=BN_num_bits(p);
 
         if (BN_is_odd(p))
-                { if (BN_copy(r,a) == NULL) goto err; }
-        else    { if (BN_one(r)) goto err; }
+                { if (BN_copy(rr,a) == NULL) goto err; }
+        else    { if (!BN_one(rr)) goto err; }
 
         for (i=1; i<bits; i++)
                 {
-                if (!BN_sqr(tmp,v,ctx)) goto err;
+                if (!BN_sqr(v,v,ctx)) goto err;
                 if (BN_is_bit_set(p,i))
                         {
-                        if (!BN_mul(tmp,r,v)) goto err;
+                        if (!BN_mul(rr,rr,v,ctx)) goto err;
                         }
                 }
         ret=1;
 err:
-        ctx->tos-=2;
+        ctx->tos=tos;
+        if (r != rr) BN_copy(r,rr);
         return(ret);
         }
 
-int BN_mod_exp(r,a,p,m,ctx)
-BIGNUM *r;
-BIGNUM *a;
-BIGNUM *p;
-BIGNUM *m;
-BN_CTX *ctx;
+int BN_mod_exp(BIGNUM *r, 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);
+
 #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
@@ -182,20 +184,16 @@ BN_CTX *ctx;
         }
 
 /* #ifdef RECP_MUL_MOD */
-int BN_mod_exp_recp(r,a,p,m,ctx)
-BIGNUM *r;
-BIGNUM *a;
-BIGNUM *p;
-BIGNUM *m;
-BN_CTX *ctx;
+int BN_mod_exp_recp(BIGNUM *r, const BIGNUM *a, const BIGNUM *p,
+                    const BIGNUM *m, BN_CTX *ctx)
         {
-        int nb,i,j,bits,ret=0,wstart,wend,window,wvalue;
-        int start=1;
-        BIGNUM *d,*aa;
-        BIGNUM *val[16];
+        int i,j,bits,ret=0,wstart,wend,window,wvalue;
+        int start=1,ts=0;
+        BIGNUM *aa;
+        BIGNUM val[TABLE_SIZE];
+        BN_RECP_CTX recp;
 
-        d=ctx->bn[ctx->tos++];
-        aa=ctx->bn[ctx->tos++];
+        aa= &(ctx->bn[ctx->tos++]);
         bits=BN_num_bits(p);
 
         if (bits == 0)
@@ -203,12 +201,14 @@ BN_CTX *ctx;
                 BN_one(r);
                 return(1);
                 }
-        nb=BN_reciprocal(d,m,ctx);
-        if (nb == -1) goto err;
+        BN_RECP_CTX_init(&recp);
+        if (BN_RECP_CTX_set(&recp,m,ctx) <= 0) goto err;
 
-        val[0]=BN_new();
-        if (!BN_mod(val[0],a,m,ctx)) goto err;          /* 1 */
-        if (!BN_mod_mul_reciprocal(aa,val[0],val[0],m,d,nb,ctx))
+        BN_init(&(val[0]));
+        ts=1;
+
+        if (!BN_mod(&(val[0]),a,m,ctx)) goto err;               /* 1 */
+        if (!BN_mod_mul_reciprocal(aa,&(val[0]),&(val[0]),&recp,ctx))
                 goto err;                               /* 2 */
 
         if (bits <= 17) /* This is probably 3 or 0x10001, so just do singles */
@@ -223,12 +223,11 @@ BN_CTX *ctx;
         j=1<<(window-1);
         for (i=1; i<j; i++)
                 {
-                val[i]=BN_new();
-                if (!BN_mod_mul_reciprocal(val[i],val[i-1],aa,m,d,nb,ctx))
+                BN_init(&val[i]);
+                if (!BN_mod_mul_reciprocal(&(val[i]),&(val[i-1]),aa,&recp,ctx))
                         goto err;
                 }
-        for (; i<16; i++)
-                val[i]=NULL;
+        ts=i;
 
         start=1;        /* This is used to avoid multiplication etc
                          * when there is only the value '1' in the
@@ -244,7 +243,7 @@ BN_CTX *ctx;
                 if (BN_is_bit_set(p,wstart) == 0)
                         {
                         if (!start)
-                                if (!BN_mod_mul_reciprocal(r,r,r,m,d,nb,ctx))
+                                if (!BN_mod_mul_reciprocal(r,r,r,&recp,ctx))
                                 goto err;
                         if (wstart == 0) break;
                         wstart--;
@@ -274,12 +273,12 @@ BN_CTX *ctx;
                 if (!start)
                         for (i=0; i<j; i++)
                                 {
-                                if (!BN_mod_mul_reciprocal(r,r,r,m,d,nb,ctx))
+                                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],m,d,nb,ctx))
+                if (!BN_mod_mul_reciprocal(r,r,&(val[wvalue>>1]),&recp,ctx))
                         goto err;
 
                 /* move the 'window' down further */
@@ -290,35 +289,36 @@ BN_CTX *ctx;
                 }
         ret=1;
 err:
-        ctx->tos-=2;
-        for (i=0; i<16; i++)
-                if (val[i] != NULL) BN_clear_free(val[i]);
+        ctx->tos--;
+        for (i=0; i<ts; i++)
+                BN_clear_free(&(val[i]));
+        BN_RECP_CTX_free(&recp);
         return(ret);
         }
 /* #endif */
 
 /* #ifdef MONT_MUL_MOD */
-int BN_mod_exp_mont(r,a,p,m,ctx,in_mont)
-BIGNUM *r;
-BIGNUM *a;
-BIGNUM *p;
-BIGNUM *m;
-BN_CTX *ctx;
-BN_MONT_CTX *in_mont;
+int BN_mod_exp_mont(BIGNUM *rr, BIGNUM *a, const BIGNUM *p,
+                    const BIGNUM *m, BN_CTX *ctx, BN_MONT_CTX *in_mont)
         {
-#define TABLE_SIZE      16
         int i,j,bits,ret=0,wstart,wend,window,wvalue;
-        int start=1;
-        BIGNUM *d,*aa;
-        BIGNUM *val[TABLE_SIZE];
+        int start=1,ts=0;
+        BIGNUM *d,*r;
+        BIGNUM *aa;
+        BIGNUM val[TABLE_SIZE];
         BN_MONT_CTX *mont=NULL;
 
+        bn_check_top(a);
+        bn_check_top(p);
+        bn_check_top(m);
+
         if (!(m->d[0] & 1))
                 {
                 BNerr(BN_F_BN_MOD_EXP_MONT,BN_R_CALLED_WITH_EVEN_MODULUS);
                 return(0);
                 }
-        d=ctx->bn[ctx->tos++];
+        d= &(ctx->bn[ctx->tos++]);
+        r= &(ctx->bn[ctx->tos++]);
         bits=BN_num_bits(p);
         if (bits == 0)
                 {
@@ -339,22 +339,23 @@ BN_MONT_CTX *in_mont;
                 if (!BN_MONT_CTX_set(mont,m,ctx)) goto err;
                 }
 
-        val[0]=BN_new();
+        BN_init(&val[0]);
+        ts=1;
         if (BN_ucmp(a,m) >= 0)
                 {
-                BN_mod(val[0],a,m,ctx);
-                aa=val[0];
+                BN_mod(&(val[0]),a,m,ctx);
+                aa= &(val[0]);
                 }
         else
                 aa=a;
-        if (!BN_to_montgomery(val[0],aa,mont,ctx)) goto err; /* 1 */
-        if (!BN_mod_mul_montgomery(d,val[0],val[0],mont,ctx)) goto err; /* 2 */
+        if (!BN_to_montgomery(&(val[0]),aa,mont,ctx)) goto err; /* 1 */
+        if (!BN_mod_mul_montgomery(d,&(val[0]),&(val[0]),mont,ctx)) goto err; /* 2 */
 
         if (bits <= 20) /* This is probably 3 or 0x10001, so just do singles */
                 window=1;
-        else if (bits > 250)
+        else if (bits >= 256)
                 window=5;       /* max size of window */
-        else if (bits >= 120)
+        else if (bits >= 128)
                 window=4;
         else
                 window=3;
@@ -362,12 +363,11 @@ BN_MONT_CTX *in_mont;
         j=1<<(window-1);
         for (i=1; i<j; i++)
                 {
-                val[i]=BN_new();
-                if (!BN_mod_mul_montgomery(val[i],val[i-1],d,mont,ctx))
+                BN_init(&(val[i]));
+                if (!BN_mod_mul_montgomery(&(val[i]),&(val[i-1]),d,mont,ctx))
                         goto err;
                 }
-        for (; i<TABLE_SIZE; i++)
-                val[i]=NULL;
+        ts=i;
 
         start=1;        /* This is used to avoid multiplication etc
                          * when there is only the value '1' in the
@@ -419,7 +419,7 @@ BN_MONT_CTX *in_mont;
                                 }
                 
                 /* wvalue will be an odd number < 2^window */
-                if (!BN_mod_mul_montgomery(r,r,val[wvalue>>1],mont,ctx))
+                if (!BN_mod_mul_montgomery(r,r,&(val[wvalue>>1]),mont,ctx))
                         goto err;
 
                 /* move the 'window' down further */
@@ -428,31 +428,27 @@ BN_MONT_CTX *in_mont;
                 start=0;
                 if (wstart < 0) break;
                 }
-        BN_from_montgomery(r,r,mont,ctx);
+        BN_from_montgomery(rr,r,mont,ctx);
         ret=1;
 err:
         if ((in_mont == NULL) && (mont != NULL)) BN_MONT_CTX_free(mont);
-        ctx->tos--;
-        for (i=0; i<TABLE_SIZE; i++)
-                if (val[i] != NULL) BN_clear_free(val[i]);
+        ctx->tos-=2;
+        for (i=0; i<ts; i++)
+                BN_clear_free(&(val[i]));
         return(ret);
         }
 /* #endif */
 
 /* The old fallback, simple version :-) */
-int BN_mod_exp_simple(r,a,p,m,ctx)
-BIGNUM *r;
-BIGNUM *a;
-BIGNUM *p;
-BIGNUM *m;
-BN_CTX *ctx;
+int BN_mod_exp_simple(BIGNUM *r, BIGNUM *a, BIGNUM *p, BIGNUM *m,
+             BN_CTX *ctx)
         {
-        int i,j,bits,ret=0,wstart,wend,window,wvalue;
+        int i,j,bits,ret=0,wstart,wend,window,wvalue,ts=0;
         int start=1;
         BIGNUM *d;
-        BIGNUM *val[16];
+        BIGNUM val[TABLE_SIZE];
 
-        d=ctx->bn[ctx->tos++];
+        d= &(ctx->bn[ctx->tos++]);
         bits=BN_num_bits(p);
 
         if (bits == 0)
@@ -461,9 +457,10 @@ BN_CTX *ctx;
                 return(1);
                 }
 
-        val[0]=BN_new();
-        if (!BN_mod(val[0],a,m,ctx)) goto err;          /* 1 */
-        if (!BN_mod_mul(d,val[0],val[0],m,ctx))
+        BN_init(&(val[0]));
+        ts=1;
+        if (!BN_mod(&(val[0]),a,m,ctx)) goto err;               /* 1 */
+        if (!BN_mod_mul(d,&(val[0]),&(val[0]),m,ctx))
                 goto err;                               /* 2 */
 
         if (bits <= 17) /* This is probably 3 or 0x10001, so just do singles */
@@ -478,12 +475,11 @@ BN_CTX *ctx;
         j=1<<(window-1);
         for (i=1; i<j; i++)
                 {
-                val[i]=BN_new();
-                if (!BN_mod_mul(val[i],val[i-1],d,m,ctx))
+                BN_init(&(val[i]));
+                if (!BN_mod_mul(&(val[i]),&(val[i-1]),d,m,ctx))
                         goto err;
                 }
-        for (; i<16; i++)
-                val[i]=NULL;
+        ts=i;
 
         start=1;        /* This is used to avoid multiplication etc
                          * when there is only the value '1' in the
@@ -534,7 +530,7 @@ BN_CTX *ctx;
                                 }
                 
                 /* wvalue will be an odd number < 2^window */
-                if (!BN_mod_mul(r,r,val[wvalue>>1],m,ctx))
+                if (!BN_mod_mul(r,r,&(val[wvalue>>1]),m,ctx))
                         goto err;
 
                 /* move the 'window' down further */
@@ -546,8 +542,8 @@ BN_CTX *ctx;
         ret=1;
 err:
         ctx->tos--;
-        for (i=0; i<16; i++)
-                if (val[i] != NULL) BN_clear_free(val[i]);
+        for (i=0; i<ts; i++)
+                BN_clear_free(&(val[i]));
         return(ret);
         }