Generate just one error code if iterated SSL_CTX_get() fails.

Avoid enabled 'assert()' in production library.

3 files changed, 31 insertions, 5 deletions

diff --git a/crypto/bn/Makefile.ssl b/crypto/bn/Makefile.ssl
index 94da20bd5a..3b7b29827c 100644
--- a/crypto/bn/Makefile.ssl
+++ b/crypto/bn/Makefile.ssl
@@ -185,6 +185,12 @@ bn_blind.o: ../../include/openssl/e_os.h ../../include/openssl/e_os2.h
 bn_blind.o: ../../include/openssl/err.h ../../include/openssl/opensslconf.h
 bn_blind.o: ../../include/openssl/opensslv.h ../../include/openssl/safestack.h
 bn_blind.o: ../../include/openssl/stack.h ../cryptlib.h bn_lcl.h
+bn_ctx.o: ../../include/openssl/bio.h ../../include/openssl/bn.h
+bn_ctx.o: ../../include/openssl/buffer.h ../../include/openssl/crypto.h
+bn_ctx.o: ../../include/openssl/e_os.h ../../include/openssl/e_os2.h
+bn_ctx.o: ../../include/openssl/err.h ../../include/openssl/opensslconf.h
+bn_ctx.o: ../../include/openssl/opensslv.h ../../include/openssl/safestack.h
+bn_ctx.o: ../../include/openssl/stack.h ../cryptlib.h
 bn_div.o: ../../include/openssl/bio.h ../../include/openssl/bn.h
 bn_div.o: ../../include/openssl/buffer.h ../../include/openssl/crypto.h
 bn_div.o: ../../include/openssl/e_os.h ../../include/openssl/e_os2.h
diff --git a/crypto/bn/bn_ctx.c b/crypto/bn/bn_ctx.c
index 8b079e237f..f72b075ccf 100644
--- a/crypto/bn/bn_ctx.c
+++ b/crypto/bn/bn_ctx.c
@@ -54,6 +54,11 @@
  *
  */
 
+#ifndef BN_CTX_DEBUG
+# undef NDEBUG /* avoid conflicting definitions */
+# define NDEBUG
+#endif
+
 #include <stdio.h>
 #include <assert.h>
 #include "cryptlib.h"
@@ -101,14 +106,21 @@ void BN_CTX_free(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)
 	{
-	if (ctx->tos >= BN_CTX_NUM)
+	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 SSL_CTX_end is called: */
+			ctx->too_many = 1;
+			}
 		return NULL;
 		}
 	return (&(ctx->bn[ctx->tos++]));
@@ -118,6 +130,14 @@ void BN_CTX_end(BN_CTX *ctx)
 	{
 	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->tos = ctx->pos[ctx->depth];
+	if (ctx->depth < BN_CTX_NUM_POS)
+		ctx->tos = ctx->pos[ctx->depth];
 	}
diff --git a/crypto/bn/bn_err.c b/crypto/bn/bn_err.c
index de3aaeb034..f3b9497dca 100644
--- a/crypto/bn/bn_err.c
+++ b/crypto/bn/bn_err.c
@@ -71,7 +71,7 @@ static ERR_STRING_DATA BN_str_functs[]=
 {ERR_PACK(0,BN_F_BN_BLINDING_UPDATE,0),	"BN_BLINDING_update"},
 {ERR_PACK(0,BN_F_BN_BN2DEC,0),	"BN_bn2dec"},
 {ERR_PACK(0,BN_F_BN_BN2HEX,0),	"BN_bn2hex"},
-{ERR_PACK(0,BN_F_BN_CTX_GET,0),	"BN_CTX_GET"},
+{ERR_PACK(0,BN_F_BN_CTX_GET,0),	"BN_CTX_get"},
 {ERR_PACK(0,BN_F_BN_CTX_NEW,0),	"BN_CTX_new"},
 {ERR_PACK(0,BN_F_BN_DIV,0),	"BN_div"},
 {ERR_PACK(0,BN_F_BN_EXPAND2,0),	"bn_expand2"},