BN_div bugfix. The q-- loop should not be entered in the n0==d0 case.

[openssl.git] / crypto / bn / bn_gcd.c

diff --git a/crypto/bn/bn_gcd.c b/crypto/bn/bn_gcd.c
index 071bba3b4b3a0521359682c21e69e94e8d4f6f05..398207196be841403cc5c2b3caf36e9c7cb8e9a4 100644 (file)
--- a/crypto/bn/bn_gcd.c
+++ b/crypto/bn/bn_gcd.c
@@ -60,21 +60,20 @@
 #include "cryptlib.h"
 #include "bn_lcl.h"
 
-#ifndef NOPROTO
 static BIGNUM *euclid(BIGNUM *a, BIGNUM *b);
-#else
-static BIGNUM *euclid();
-#endif
 
-int BN_gcd(r,in_a,in_b,ctx)
-BIGNUM *r,*in_a,*in_b;
-BN_CTX *ctx;
+int BN_gcd(BIGNUM *r, BIGNUM *in_a, BIGNUM *in_b, BN_CTX *ctx)
        {
        BIGNUM *a,*b,*t;
        int ret=0;
 
-       a=ctx->bn[ctx->tos];
-       b=ctx->bn[ctx->tos+1];
+       bn_check_top(in_a);
+       bn_check_top(in_b);
+
+       BN_CTX_start(ctx);
+       a = BN_CTX_get(ctx);
+       b = BN_CTX_get(ctx);
+       if (a == NULL || b == NULL) goto err;
 
        if (BN_copy(a,in_a) == NULL) goto err;
        if (BN_copy(b,in_b) == NULL) goto err;
@@ -86,15 +85,18 @@ BN_CTX *ctx;
        if (BN_copy(r,t) == NULL) goto err;
        ret=1;
 err:
+       BN_CTX_end(ctx);
        return(ret);
        }
 
-static BIGNUM *euclid(a,b)
-BIGNUM *a,*b;
+static BIGNUM *euclid(BIGNUM *a, BIGNUM *b)
        {
        BIGNUM *t;
        int shifts=0;
 
+       bn_check_top(a);
+       bn_check_top(b);
+
        for (;;)
                {
                if (BN_is_zero(b))
@@ -142,23 +144,28 @@ err:
        }
 
 /* solves ax == 1 (mod n) */
-BIGNUM *BN_mod_inverse(a, n, ctx)
-BIGNUM *a;
-BIGNUM *n;
-BN_CTX *ctx;
+BIGNUM *BN_mod_inverse(BIGNUM *in, BIGNUM *a, const BIGNUM *n, BN_CTX *ctx)
        {
-       BIGNUM *A,*B,*X,*Y,*M,*D,*R;
-       BIGNUM *ret=NULL,*T;
+       BIGNUM *A,*B,*X,*Y,*M,*D,*R=NULL;
+       BIGNUM *T,*ret=NULL;
        int sign;
 
-       A=ctx->bn[ctx->tos];
-       B=ctx->bn[ctx->tos+1];
-       X=ctx->bn[ctx->tos+2];
-       D=ctx->bn[ctx->tos+3];
-       M=ctx->bn[ctx->tos+4];
-       Y=ctx->bn[ctx->tos+5];
-       ctx->tos+=6;
-       R=BN_new();
+       bn_check_top(a);
+       bn_check_top(n);
+
+       BN_CTX_start(ctx);
+       A = BN_CTX_get(ctx);
+       B = BN_CTX_get(ctx);
+       X = BN_CTX_get(ctx);
+       D = BN_CTX_get(ctx);
+       M = BN_CTX_get(ctx);
+       Y = BN_CTX_get(ctx);
+       if (Y == NULL) goto err;
+
+       if (in == NULL)
+               R=BN_new();
+       else
+               R=in;
        if (R == NULL) goto err;
 
        BN_zero(X);
@@ -175,7 +182,7 @@ BN_CTX *ctx;
                B=M;
                /* T has a struct, M does not */
 
-               if (!BN_mul(T,D,X)) goto err;
+               if (!BN_mul(T,D,X,ctx)) goto err;
                if (!BN_add(T,T,Y)) goto err;
                M=Y;
                Y=X;
@@ -196,8 +203,8 @@ BN_CTX *ctx;
                }
        ret=R;
 err:
-       if ((ret == NULL) && (R != NULL)) BN_free(R);
-       ctx->tos-=6;
+       if ((ret == NULL) && (in == NULL)) BN_free(R);
+       BN_CTX_end(ctx);
        return(ret);
        }