rpc: Convert attribute value for portability

When using the RPC across multiple architectures, where data models
are different, say LP64 vs ILP32, there can be unwanted truncation of
attribute values.

This patch converts the values into portable format for the known
attributes.

Co-authored-by: Nikos Mavrogiannopoulos <nmav@redhat.com>

1 files changed, 23 insertions, 40 deletions

diff --git a/p11-kit/rpc-client.c b/p11-kit/rpc-client.c
index c69dcfd..3521ddd 100644
--- a/p11-kit/rpc-client.c
+++ b/p11-kit/rpc-client.c
@@ -196,11 +196,7 @@ proto_read_attribute_array (p11_rpc_message *msg,
                             CK_ATTRIBUTE_PTR arr,
                             CK_ULONG len)
 {
-	uint32_t i, num, value, type;
-	CK_ATTRIBUTE_PTR attr;
-	const unsigned char *attrval = NULL;
-	size_t attrlen = 0;
-	unsigned char validity;
+	uint32_t i, num;
 	CK_RV ret;
 
 	assert (len != 0);
@@ -229,62 +225,49 @@ proto_read_attribute_array (p11_rpc_message *msg,
 
 	/* We need to go ahead and read everything in all cases */
 	for (i = 0; i < num; ++i) {
+		size_t offset = msg->parsed;
+		CK_ATTRIBUTE temp;
 
-		/* The attribute type */
-		p11_rpc_buffer_get_uint32 (msg->input, &msg->parsed, &type);
-
-		/* Attribute validity */
-		p11_rpc_buffer_get_byte (msg->input, &msg->parsed, &validity);
-
-		/* And the data itself */
-		if (validity) {
-			if (p11_rpc_buffer_get_uint32 (msg->input, &msg->parsed, &value) &&
-			    p11_rpc_buffer_get_byte_array (msg->input, &msg->parsed, &attrval, &attrlen)) {
-				if (attrval && value != attrlen) {
-					p11_message ("attribute length does not match attribute data");
-					return PARSE_ERROR;
-				}
-				attrlen = value;
-			}
+		memset (&temp, 0, sizeof (temp));
+		if (!p11_rpc_buffer_get_attribute (msg->input, &offset, &temp)) {
+			msg->parsed = offset;
+			return PARSE_ERROR;
 		}
 
-		/* Don't act on this data unless no errors */
-		if (p11_buffer_failed (msg->input))
-			break;
-
 		/* Try and stuff it in the output data */
 		if (arr) {
-			attr = &(arr[i]);
-			if (attr->type != type) {
+			CK_ATTRIBUTE *attr = &(arr[i]);
+
+			if (temp.type != attr->type) {
 				p11_message ("returned attributes in invalid order");
+				msg->parsed = offset;
 				return PARSE_ERROR;
 			}
 
-			if (validity) {
+			if (temp.ulValueLen != ((CK_ULONG)-1)) {
 				/* Just requesting the attribute size */
 				if (!attr->pValue) {
-					attr->ulValueLen = attrlen;
+					attr->ulValueLen = temp.ulValueLen;
 
 				/* Wants attribute data, but too small */
-				} else if (attr->ulValueLen < attrlen) {
-					attr->ulValueLen = attrlen;
+				} else if (attr->ulValueLen < temp.ulValueLen) {
+					attr->ulValueLen = temp.ulValueLen;
 					ret = CKR_BUFFER_TOO_SMALL;
 
-				/* Wants attribute data, value is null */
-				} else if (attrval == NULL) {
-					attr->ulValueLen = 0;
-
 				/* Wants attribute data, enough space */
 				} else {
-					attr->ulValueLen = attrlen;
-					memcpy (attr->pValue, attrval, attrlen);
+					size_t offset2 = msg->parsed;
+					if (!p11_rpc_buffer_get_attribute (msg->input, &offset2, attr)) {
+						msg->parsed = offset2;
+						return PARSE_ERROR;
+					}
 				}
-
-			/* Not a valid attribute */
 			} else {
-				attr->ulValueLen = ((CK_ULONG)-1);
+				attr->ulValueLen = temp.ulValueLen;
 			}
 		}
+
+		msg->parsed = offset;
 	}
 
 	if (p11_buffer_failed (msg->input))