Hide BN_CTX structure details.

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

diff --git a/crypto/bn/bn_ctx.c b/crypto/bn/bn_ctx.c
index 8b079e237f1b569995ff630898a2e725fea6a04f..7daf19eb8436cf42bfec2aaba2a1866353b642b0 100644 (file)
--- a/crypto/bn/bn_ctx.c
+++ b/crypto/bn/bn_ctx.c
@@ -54,17 +54,23 @@
  *
  */
 
  *
  */
 

+#ifndef BN_CTX_DEBUG
+# undef NDEBUG /* avoid conflicting definitions */
+# define NDEBUG
+#endif
+

 #include <stdio.h>
 #include <assert.h>
 #include <stdio.h>
 #include <assert.h>

+

 #include "cryptlib.h"
 #include "cryptlib.h"

-#include <openssl/bn.h>
+#include "bn_lcl.h"

 
 
 BN_CTX *BN_CTX_new(void)
        {
        BN_CTX *ret;
 
 
 
 BN_CTX *BN_CTX_new(void)
        {
        BN_CTX *ret;
 

-       ret=(BN_CTX *)Malloc(sizeof(BN_CTX));
+       ret=(BN_CTX *)OPENSSL_malloc(sizeof(BN_CTX));

        if (ret == NULL)
                {
                BNerr(BN_F_BN_CTX_NEW,ERR_R_MALLOC_FAILURE);
        if (ret == NULL)
                {
                BNerr(BN_F_BN_CTX_NEW,ERR_R_MALLOC_FAILURE);


@@ -78,12 +84,17 @@ BN_CTX *BN_CTX_new(void)
 
 void BN_CTX_init(BN_CTX *ctx)
        {
 
 void BN_CTX_init(BN_CTX *ctx)
        {

+#if 0 /* explicit version */

        int i;
        ctx->tos = 0;
        ctx->flags = 0;
        ctx->depth = 0;
        int i;
        ctx->tos = 0;
        ctx->flags = 0;
        ctx->depth = 0;

+       ctx->too_many = 0;

        for (i = 0; i < BN_CTX_NUM; i++)
                BN_init(&(ctx->bn[i]));
        for (i = 0; i < BN_CTX_NUM; i++)
                BN_init(&(ctx->bn[i]));

+#else
+       memset(ctx, 0, sizeof *ctx);
+#endif

        }
 
 void BN_CTX_free(BN_CTX *ctx)
        }
 
 void BN_CTX_free(BN_CTX *ctx)


@@ -96,19 +107,32 @@ void BN_CTX_free(BN_CTX *ctx)
        for (i=0; i < BN_CTX_NUM; i++)
                BN_clear_free(&(ctx->bn[i]));
        if (ctx->flags & BN_FLG_MALLOCED)
        for (i=0; i < BN_CTX_NUM; i++)
                BN_clear_free(&(ctx->bn[i]));
        if (ctx->flags & BN_FLG_MALLOCED)

-               Free(ctx);
+               OPENSSL_free(ctx);

        }
 
 void BN_CTX_start(BN_CTX *ctx)
        {
        }
 
 void BN_CTX_start(BN_CTX *ctx)
        {

-       ctx->pos[ctx->depth++] = ctx->tos;
+       if (ctx->depth < BN_CTX_NUM_POS)
+               ctx->pos[ctx->depth] = ctx->tos;
+       ctx->depth++;

        }
 
        }
 

+

 BIGNUM *BN_CTX_get(BN_CTX *ctx)
        {
 BIGNUM *BN_CTX_get(BN_CTX *ctx)
        {

-       if (ctx->tos >= BN_CTX_NUM)
+       /* Note: If BN_CTX_get is ever changed to allocate BIGNUMs dynamically,
+        * make sure that if BN_CTX_get fails once it will return NULL again
+        * until BN_CTX_end is called.  (This is so that callers have to check
+        * only the last return value.)
+        */
+       if (ctx->depth > BN_CTX_NUM_POS || ctx->tos >= BN_CTX_NUM)

                {
                {

-               BNerr(BN_F_BN_CTX_GET,BN_R_TOO_MANY_TEMPORARY_VARIABLES);
+               if (!ctx->too_many)
+                       {
+                       BNerr(BN_F_BN_CTX_GET,BN_R_TOO_MANY_TEMPORARY_VARIABLES);
+                       /* disable error code until BN_CTX_end is called: */
+                       ctx->too_many = 1;
+                       }

                return NULL;
                }
        return (&(ctx->bn[ctx->tos++]));
                return NULL;
                }
        return (&(ctx->bn[ctx->tos++]));


@@ -118,6 +142,14 @@ void BN_CTX_end(BN_CTX *ctx)
        {
        if (ctx == NULL) return;
        assert(ctx->depth > 0);
        {
        if (ctx == NULL) return;
        assert(ctx->depth > 0);

+       if (ctx->depth == 0)
+               /* should never happen, but we can tolerate it if not in
+                * debug mode (could be a 'goto err' in the calling function
+                * before BN_CTX_start was reached) */
+               BN_CTX_start(ctx);
+
+       ctx->too_many = 0;

        ctx->depth--;
        ctx->depth--;

-       ctx->tos = ctx->pos[ctx->depth];
+       if (ctx->depth < BN_CTX_NUM_POS)
+               ctx->tos = ctx->pos[ctx->depth];

        }
        }