Addenum to "Constify obj_dat.[ch]."

1 files changed, 15 insertions, 7 deletions

diff --git a/crypto/asn1/a_object.c b/crypto/asn1/a_object.c
index 6a421a66a6..6e4ae3b073 100644
--- a/crypto/asn1/a_object.c
+++ b/crypto/asn1/a_object.c
@@ -287,6 +287,7 @@ ASN1_OBJECT *c2i_ASN1_OBJECT(ASN1_OBJECT **a, const unsigned char **pp,
 	{
 	ASN1_OBJECT *ret=NULL;
 	const unsigned char *p;
+	unsigned char *data;
 	int i;
 
 	/* only the ASN1_OBJECTs from the 'table' will have values
@@ -299,15 +300,22 @@ ASN1_OBJECT *c2i_ASN1_OBJECT(ASN1_OBJECT **a, const unsigned char **pp,
 	else	ret=(*a);
 
 	p= *pp;
-	if ((ret->data == NULL) || (ret->length < len))
+	/* detach data from object */
+	data = (unsigned char *)ret->data;
+	ret->data = NULL;
+	/* once detached we can change it */
+	if ((data == NULL) || (ret->length < len))
 		{
-		if (ret->data != NULL) OPENSSL_free(ret->data);
-		ret->data=(unsigned char *)OPENSSL_malloc(len ? (int)len : 1);
-		ret->flags|=ASN1_OBJECT_FLAG_DYNAMIC_DATA;
-		if (ret->data == NULL)
+		ret->length=0;
+		if (data != NULL) OPENSSL_free(data);
+		data=(unsigned char *)OPENSSL_malloc(len ? (int)len : 1);
+		if (data == NULL)
 			{ i=ERR_R_MALLOC_FAILURE; goto err; }
+		ret->flags|=ASN1_OBJECT_FLAG_DYNAMIC_DATA;
 		}
-	memcpy(ret->data,p,(int)len);
+	memcpy(data,p,(int)len);
+	/* reattach data to object, after which it remains const */
+	ret->data  =data;
 	ret->length=(int)len;
 	ret->sn=NULL;
 	ret->ln=NULL;
@@ -356,7 +364,7 @@ void ASN1_OBJECT_free(ASN1_OBJECT *a)
 		}
 	if (a->flags & ASN1_OBJECT_FLAG_DYNAMIC_DATA)
 		{
-		if (a->data != NULL) OPENSSL_free(a->data);
+		if (a->data != NULL) OPENSSL_free((void *)a->data);
 		a->data=NULL;
 		a->length=0;
 		}