Fix RPC calls: ATTRIBUTE buf not null but length 0

Let's add a support for cases when the buffer != NULL but the
length is 0. According to Oasis, buffer = NULL and length = 0
means a query of the length so the subsequent calls with a
buffer != NULL should fill then buffer when length is long enough.
If not, according to Oasis, one should get a CKR_BUFFER_TOO_SMALL.

See the previous commit for IN_ULONG_BUFFER(). This patch is
follow a similar design pattern.

Fix: issue #257

diff --git a/p11-kit/rpc-message.c b/p11-kit/rpc-message.c
index 3039a3d5d02fe030e8926595c634d721189c827f..1f8fbc2167ca7bce5db54b89a2a604e108215d2f 100644 (file)
--- a/p11-kit/rpc-message.c
+++ b/p11-kit/rpc-message.c
@@ -241,14 +241,20 @@ p11_rpc_message_write_attribute_buffer (p11_rpc_message *msg,
        /* Write the number of items */
        p11_rpc_buffer_add_uint32 (msg->output, num);
 
+       /* Is arr not null ? */
+       p11_rpc_buffer_add_byte (msg->output, arr ? 0 : 1);
+
        for (i = 0; i < num; ++i) {
                attr = &(arr[i]);
 
                /* The attribute type */
                p11_rpc_buffer_add_uint32 (msg->output, attr->type);
 
+               /* rpc_server.c:value_is_null, is the value buffer not NULL ? */
+               p11_rpc_buffer_add_byte (msg->output, attr->pValue ? 0 : 1);
+
                /* And the attribute buffer length */
-               p11_rpc_buffer_add_uint32 (msg->output, attr->pValue ? attr->ulValueLen : 0);
+               p11_rpc_buffer_add_uint32 (msg->output, attr->ulValueLen);
        }
 
        return !p11_buffer_failed (msg->output);

diff --git a/p11-kit/rpc-server.c b/p11-kit/rpc-server.c
index 764ad34087c08962f7174f1bb68af0f317665fc1..297d2e77c54a62870c2508b48611a4f86591bbee 100644 (file)
--- a/p11-kit/rpc-server.c
+++ b/p11-kit/rpc-server.c
@@ -237,6 +237,7 @@ proto_read_attribute_buffer (p11_rpc_message *msg,
 {
        CK_ATTRIBUTE_PTR attrs;
        uint32_t n_attrs, i;
+       uint8_t attrs_is_null;
        uint32_t value;
 
        assert (msg != NULL);
@@ -251,6 +252,16 @@ proto_read_attribute_buffer (p11_rpc_message *msg,
        if (!p11_rpc_buffer_get_uint32 (msg->input, &msg->parsed, &n_attrs))
                return PARSE_ERROR;
 
+       /* Is attrs pointer null or not ? */
+       if (!p11_rpc_buffer_get_byte (msg->input, &msg->parsed, &attrs_is_null))
+               return PARSE_ERROR;
+
+       if (attrs_is_null) {
+               *result = NULL;
+               *n_result = n_attrs;
+               return CKR_OK;
+       }
+
        /* Allocate memory for the attribute structures */
        attrs = p11_rpc_message_alloc_extra (msg, n_attrs * sizeof (CK_ATTRIBUTE));
        if (attrs == NULL)
@@ -258,6 +269,7 @@ proto_read_attribute_buffer (p11_rpc_message *msg,
 
        /* Now go through and fill in each one */
        for (i = 0; i < n_attrs; ++i) {
+               uint8_t value_is_null;
 
                /* The attribute type */
                if (!p11_rpc_buffer_get_uint32 (msg->input, &msg->parsed, &value))
@@ -265,18 +277,22 @@ proto_read_attribute_buffer (p11_rpc_message *msg,
 
                attrs[i].type = value;
 
+               /* Is the value buffer not NULL ?  */
+               if (!p11_rpc_buffer_get_byte (msg->input, &msg->parsed, &value_is_null))
+                       return PARSE_ERROR;
+
                /* The number of bytes to allocate */
                if (!p11_rpc_buffer_get_uint32 (msg->input, &msg->parsed, &value))
                        return PARSE_ERROR;
 
-               if (value == 0) {
+               attrs[i].ulValueLen = value;
+
+               if (value_is_null) {
                        attrs[i].pValue = NULL;
-                       attrs[i].ulValueLen = 0;
                } else {
                        attrs[i].pValue = p11_rpc_message_alloc_extra (msg, value);
                        if (!attrs[i].pValue)
                                return CKR_DEVICE_MEMORY;
-                       attrs[i].ulValueLen = value;
                }
        }