ldb:ldb_msg.c - make "ldb_msg_find_attr_as_*" more robust against invalid values

- Integer handling was modeled after validate code from "schema_syntax.c".
- Double handling was modeled similar, but with a dynamic buffer.
  I don't know if there is a maximum literal length for double values but an
  allocation shouldn't a problem here since doubles are rare.
- String handlind is enhanced with a terminating "0" test for safety.

Reviewed-by: abartlet + metze

Autobuild-User: Matthias Dieter Wallnöfer <mdw@samba.org>
Autobuild-Date: Thu Apr  7 16:38:57 CEST 2011 on sn-devel-104

1 files changed, 106 insertions, 19 deletions

diff --git a/source4/lib/ldb/common/ldb_msg.c b/source4/lib/ldb/common/ldb_msg.c
index 8060476d7d..9c5a279b8a 100644
--- a/source4/lib/ldb/common/ldb_msg.c
+++ b/source4/lib/ldb/common/ldb_msg.c
@@ -391,30 +391,63 @@ int ldb_msg_find_attr_as_int(const struct ldb_message *msg,
 			     int default_value)
 {
 	const struct ldb_val *v = ldb_msg_find_ldb_val(msg, attr_name);
+	char buf[sizeof("-2147483648")];
+	char *end = NULL;
+	int ret;
+
 	if (!v || !v->data) {
 		return default_value;
 	}
-	return strtol((const char *)v->data, NULL, 0);
+
+	ZERO_STRUCT(buf);
+	if (v->length >= sizeof(buf)) {
+		return default_value;
+	}
+
+	memcpy(buf, v->data, v->length);
+	errno = 0;
+	ret = (int) strtoll(buf, &end, 10);
+	if (errno != 0) {
+		return default_value;
+	}
+	if (end && end[0] != '\0') {
+		return default_value;
+	}
+	return ret;
 }
 
-unsigned int ldb_msg_find_attr_as_uint(const struct ldb_message *msg, 
+unsigned int ldb_msg_find_attr_as_uint(const struct ldb_message *msg,
 				       const char *attr_name,
 				       unsigned int default_value)
 {
-	unsigned int ret;
 	const struct ldb_val *v = ldb_msg_find_ldb_val(msg, attr_name);
+	char buf[sizeof("-2147483648")];
+	char *end = NULL;
+	unsigned int ret;
+
 	if (!v || !v->data) {
 		return default_value;
 	}
 
-	/* in LDAP there're only int32_t values */
-	errno = 0;
-	ret = strtol((const char *)v->data, NULL, 0);
-	if (errno == 0) {
-		return ret;
+	ZERO_STRUCT(buf);
+	if (v->length >= sizeof(buf)) {
+		return default_value;
 	}
 
-	return strtoul((const char *)v->data, NULL, 0);
+	memcpy(buf, v->data, v->length);
+	errno = 0;
+	ret = (unsigned int) strtoll(buf, &end, 10);
+	if (errno != 0) {
+		errno = 0;
+		ret = (unsigned int) strtoull(buf, &end, 10);
+		if (errno != 0) {
+			return default_value;
+		}
+	}
+	if (end && end[0] != '\0') {
+		return default_value;
+	}
+	return ret;
 }
 
 int64_t ldb_msg_find_attr_as_int64(const struct ldb_message *msg, 
@@ -422,30 +455,63 @@ int64_t ldb_msg_find_attr_as_int64(const struct ldb_message *msg,
 				   int64_t default_value)
 {
 	const struct ldb_val *v = ldb_msg_find_ldb_val(msg, attr_name);
+	char buf[sizeof("-9223372036854775808")];
+	char *end = NULL;
+	int64_t ret;
+
 	if (!v || !v->data) {
 		return default_value;
 	}
-	return strtoll((const char *)v->data, NULL, 0);
+
+	ZERO_STRUCT(buf);
+	if (v->length >= sizeof(buf)) {
+		return default_value;
+	}
+
+	memcpy(buf, v->data, v->length);
+	errno = 0;
+	ret = (int64_t) strtoll(buf, &end, 10);
+	if (errno != 0) {
+		return default_value;
+	}
+	if (end && end[0] != '\0') {
+		return default_value;
+	}
+	return ret;
 }
 
-uint64_t ldb_msg_find_attr_as_uint64(const struct ldb_message *msg, 
+uint64_t ldb_msg_find_attr_as_uint64(const struct ldb_message *msg,
 				     const char *attr_name,
 				     uint64_t default_value)
 {
-	uint64_t ret;
 	const struct ldb_val *v = ldb_msg_find_ldb_val(msg, attr_name);
+	char buf[sizeof("-9223372036854775808")];
+	char *end = NULL;
+	uint64_t ret;
+
 	if (!v || !v->data) {
 		return default_value;
 	}
 
-	/* in LDAP there're only int64_t values */
-	errno = 0;
-	ret = strtoll((const char *)v->data, NULL, 0);
-	if (errno == 0) {
-		return ret;
+	ZERO_STRUCT(buf);
+	if (v->length >= sizeof(buf)) {
+		return default_value;
 	}
 
-	return strtoull((const char *)v->data, NULL, 0);
+	memcpy(buf, v->data, v->length);
+	errno = 0;
+	ret = (uint64_t) strtoll(buf, &end, 10);
+	if (errno != 0) {
+		errno = 0;
+		ret = (uint64_t) strtoull(buf, &end, 10);
+		if (errno != 0) {
+			return default_value;
+		}
+	}
+	if (end && end[0] != '\0') {
+		return default_value;
+	}
+	return ret;
 }
 
 double ldb_msg_find_attr_as_double(const struct ldb_message *msg, 
@@ -453,10 +519,28 @@ double ldb_msg_find_attr_as_double(const struct ldb_message *msg,
 				   double default_value)
 {
 	const struct ldb_val *v = ldb_msg_find_ldb_val(msg, attr_name);
+	char *buf;
+	char *end = NULL;
+	double ret;
+
 	if (!v || !v->data) {
 		return default_value;
 	}
-	return strtod((const char *)v->data, NULL);
+	buf = talloc_strndup(msg, (const char *)v->data, v->length);
+	if (buf == NULL) {
+		return default_value;
+	}
+
+	errno = 0;
+	ret = strtod(buf, &end);
+	talloc_free(buf);
+	if (errno != 0) {
+		return default_value;
+	}
+	if (end && end[0] != '\0') {
+		return default_value;
+	}
+	return ret;
 }
 
 int ldb_msg_find_attr_as_bool(const struct ldb_message *msg, 
@@ -484,6 +568,9 @@ const char *ldb_msg_find_attr_as_string(const struct ldb_message *msg,
 	if (!v || !v->data) {
 		return default_value;
 	}
+	if (v->data[v->length] != '\0') {
+		return default_value;
+	}
 	return (const char *)v->data;
 }