From a005fb019f1266fac53c32a9f17d7f1e92aa2536 Mon Sep 17 00:00:00 2001
From: Andy Polyakov <appro@openssl.org>
Date: Tue, 18 Sep 2007 22:15:31 +0000
Subject: [PATCH] Addenum to "Constify obj_dat.[ch]."

---
 crypto/asn1/a_object.c   | 22 +++++++++++++++-------
 crypto/asn1/asn1.h       |  2 +-
 crypto/asn1/tasn_enc.c   |  3 ++-
 crypto/objects/obj_lib.c | 35 ++++++++++++++++++-----------------
 4 files changed, 36 insertions(+), 26 deletions(-)

diff --git a/crypto/asn1/a_object.c b/crypto/asn1/a_object.c
index 6a421a66a..6e4ae3b07 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;
 		}
diff --git a/crypto/asn1/asn1.h b/crypto/asn1/asn1.h
index eeb884fc3..1bf227d27 100644
--- a/crypto/asn1/asn1.h
+++ b/crypto/asn1/asn1.h
@@ -208,7 +208,7 @@ typedef struct asn1_object_st
 	const char *sn,*ln;
 	int nid;
 	int length;
-	unsigned char *data;
+	const unsigned char *data;	/* data remains const after init */
 	int flags;	/* Should we free this one */
 	} ASN1_OBJECT;
 
diff --git a/crypto/asn1/tasn_enc.c b/crypto/asn1/tasn_enc.c
index 28f6e4252..03e59d59c 100644
--- a/crypto/asn1/tasn_enc.c
+++ b/crypto/asn1/tasn_enc.c
@@ -569,7 +569,8 @@ int asn1_ex_i2c(ASN1_VALUE **pval, unsigned char *cout, int *putype,
 	ASN1_STRING *strtmp;
 	ASN1_OBJECT *otmp;
 	int utype;
-	unsigned char *cont, c;
+	const unsigned char *cont;
+	unsigned char c;
 	int len;
 	const ASN1_PRIMITIVE_FUNCS *pf;
 	pf = it->funcs;
diff --git a/crypto/objects/obj_lib.c b/crypto/objects/obj_lib.c
index 706fa0b0e..23e9d48cd 100644
--- a/crypto/objects/obj_lib.c
+++ b/crypto/objects/obj_lib.c
@@ -66,7 +66,8 @@ ASN1_OBJECT *OBJ_dup(const ASN1_OBJECT *o)
 	{
 	ASN1_OBJECT *r;
 	int i;
-	char *ln=NULL;
+	char *ln=NULL,*sn=NULL;
+	unsigned char *data=NULL;
 
 	if (o == NULL) return(NULL);
 	if (!(o->flags & ASN1_OBJECT_FLAG_DYNAMIC))
@@ -79,42 +80,42 @@ ASN1_OBJECT *OBJ_dup(const ASN1_OBJECT *o)
 		OBJerr(OBJ_F_OBJ_DUP,ERR_R_ASN1_LIB);
 		return(NULL);
 		}
-	r->data=OPENSSL_malloc(o->length);
-	if (r->data == NULL)
+	data=OPENSSL_malloc(o->length);
+	if (data == NULL)
 		goto err;
 	if (o->data != NULL)
-		memcpy(r->data,o->data,o->length);
+		memcpy(data,o->data,o->length);
+	/* once data attached to object it remains const */
+	r->data = data;
 	r->length=o->length;
 	r->nid=o->nid;
 	r->ln=r->sn=NULL;
 	if (o->ln != NULL)
 		{
 		i=strlen(o->ln)+1;
-		r->ln=ln=OPENSSL_malloc(i);
-		if (r->ln == NULL) goto err;
+		ln=OPENSSL_malloc(i);
+		if (ln == NULL) goto err;
 		memcpy(ln,o->ln,i);
+		r->ln=ln;
 		}
 
 	if (o->sn != NULL)
 		{
-		char *s;
-
 		i=strlen(o->sn)+1;
-		r->sn=s=OPENSSL_malloc(i);
-		if (r->sn == NULL) goto err;
-		memcpy(s,o->sn,i);
+		sn=OPENSSL_malloc(i);
+		if (sn == NULL) goto err;
+		memcpy(sn,o->sn,i);
+		r->sn=sn;
 		}
 	r->flags=o->flags|(ASN1_OBJECT_FLAG_DYNAMIC|
 		ASN1_OBJECT_FLAG_DYNAMIC_STRINGS|ASN1_OBJECT_FLAG_DYNAMIC_DATA);
 	return(r);
 err:
 	OBJerr(OBJ_F_OBJ_DUP,ERR_R_MALLOC_FAILURE);
-	if (r != NULL)
-		{
-		if (ln != NULL) OPENSSL_free(ln);
-		if (r->data != NULL) OPENSSL_free(r->data);
-		OPENSSL_free(r);
-		}
+	if (ln != NULL)		OPENSSL_free(ln);
+	if (sn != NULL)		OPENSSL_free(sn);
+	if (data != NULL)	OPENSSL_free(data);
+	if (r != NULL)		OPENSSL_free(r);
 	return(NULL);
 	}