Don't walk past the end of ldb values.

This is a partial fix towards bugs due to us walking past the end of
what we think are strings in ldb.  There is much more work to do in
this area.

Andrew Bartlett
(This used to be commit 5805a9a8f35fd90fa4f718f73534817fa3bbdfd2)

1 files changed, 16 insertions, 7 deletions

diff --git a/source4/lib/ldb/common/ldb_dn.c b/source4/lib/ldb/common/ldb_dn.c
index 08911344b7..c0d36cfbf3 100644
--- a/source4/lib/ldb/common/ldb_dn.c
+++ b/source4/lib/ldb/common/ldb_dn.c
@@ -71,7 +71,7 @@ struct ldb_dn {
 };
 
 /* strdn may be NULL */
-struct ldb_dn *ldb_dn_new(void *mem_ctx, struct ldb_context *ldb, const char *strdn)
+struct ldb_dn *ldb_dn_from_ldb_val(void *mem_ctx, struct ldb_context *ldb, const struct ldb_val *strdn)
 {
 	struct ldb_dn *dn;
 
@@ -82,27 +82,27 @@ struct ldb_dn *ldb_dn_new(void *mem_ctx, struct ldb_context *ldb, const char *st
 
 	dn->ldb = ldb;
 
-	if (strdn) {
-		if (strdn[0] == '@') {
+	if (strdn->data && strdn->length) {
+		if (strdn->data[0] == '@') {
 			dn->special = true;
 		}
-		if (strncasecmp(strdn, "<GUID=", 6) == 0) {
+		if (strdn->length >= 6 && strncasecmp((const char *)strdn->data, "<GUID=", 6) == 0) {
 			/* this is special DN returned when the
 			 * exploded_dn control is used */
 			dn->special = true;
 			/* FIXME: add a GUID string to ldb_dn structure */
-		} else if (strncasecmp(strdn, "<SID=", 8) == 0) {
+		} else if (strdn->length >= 8 && strncasecmp((const char *)strdn->data, "<SID=", 8) == 0) {
 			/* this is special DN returned when the
 			 * exploded_dn control is used */
 			dn->special = true;
 			/* FIXME: add a SID string to ldb_dn structure */
-		} else if (strncasecmp(strdn, "<WKGUID=", 8) == 0) {
+		} else if (strdn->length >= 8 && strncasecmp((const char *)strdn->data, "<WKGUID=", 8) == 0) {
 			/* this is special DN returned when the
 			 * exploded_dn control is used */
 			dn->special = true;
 			/* FIXME: add a WKGUID string to ldb_dn structure */
 		}
-		dn->linearized = talloc_strdup(dn, strdn);
+		dn->linearized = talloc_strndup(dn, (const char *)strdn->data, strdn->length);
 	} else {
 		dn->linearized = talloc_strdup(dn, "");
 	}
@@ -115,6 +115,15 @@ failed:
 	return NULL;
 }
 
+/* strdn may be NULL */
+struct ldb_dn *ldb_dn_new(void *mem_ctx, struct ldb_context *ldb, const char *strdn)
+{
+	struct ldb_val blob;
+	blob.data = strdn;
+	blob.length = strdn ? strlen(strdn) : 0;
+	return ldb_dn_from_ldb_val(mem_ctx, ldb, &blob);
+}
+
 struct ldb_dn *ldb_dn_new_fmt(void *mem_ctx, struct ldb_context *ldb, const char *new_fmt, ...)
 {
 	struct ldb_dn *dn;