/*
- * Copyright (c) 2010, JANET(UK)
+ * Copyright (c) 2011, JANET(UK)
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* SUCH DAMAGE.
*/
+/*
+ * Message protection services: determine maximum input size.
+ */
+
#include "gssapiP_eap.h"
+OM_uint32
+gss_wrap_size_limit(OM_uint32 *minor,
+ gss_ctx_id_t ctx,
+ int conf_req_flag,
+ gss_qop_t qop_req,
+ OM_uint32 req_output_size,
+ OM_uint32 *max_input_size)
+{
+ gss_iov_buffer_desc iov[4];
+ OM_uint32 major, overhead;
+
+ if (ctx == GSS_C_NO_CONTEXT) {
+ *minor = EINVAL;
+ return GSS_S_CALL_INACCESSIBLE_READ | GSS_S_NO_CONTEXT;
+ }
+
+ *minor = 0;
+
+ GSSEAP_MUTEX_LOCK(&ctx->mutex);
+
+ if (!CTX_IS_ESTABLISHED(ctx)) {
+ major = GSS_S_NO_CONTEXT;
+ *minor = GSSEAP_CONTEXT_INCOMPLETE;
+ goto cleanup;
+ }
+
+ iov[0].type = GSS_IOV_BUFFER_TYPE_HEADER;
+ iov[0].buffer.value = NULL;
+ iov[0].buffer.length = 0;
+
+ iov[1].type = GSS_IOV_BUFFER_TYPE_DATA;
+ iov[1].buffer.length = req_output_size;
+ iov[1].buffer.value = NULL;
+
+ iov[2].type = GSS_IOV_BUFFER_TYPE_PADDING;
+ iov[2].buffer.value = NULL;
+ iov[2].buffer.length = 0;
+
+ iov[3].type = GSS_IOV_BUFFER_TYPE_TRAILER;
+ iov[3].buffer.value = NULL;
+ iov[3].buffer.length = 0;
+
+ major = gssEapWrapIovLength(minor, ctx, conf_req_flag, qop_req,
+ NULL, iov, 4);
+ if (GSS_ERROR(major))
+ goto cleanup;
+
+ overhead = iov[0].buffer.length + iov[3].buffer.length;
+
+ if (iov[2].buffer.length == 0 && overhead < req_output_size)
+ *max_input_size = req_output_size - overhead;
+ else
+ *max_input_size = 0;
+
+cleanup:
+ GSSEAP_MUTEX_UNLOCK(&ctx->mutex);
+
+ return major;
+}