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-rw-r--r--src/eap_server/eap_server_tls_common.c401
1 files changed, 401 insertions, 0 deletions
diff --git a/src/eap_server/eap_server_tls_common.c b/src/eap_server/eap_server_tls_common.c
new file mode 100644
index 0000000..25ae683
--- /dev/null
+++ b/src/eap_server/eap_server_tls_common.c
@@ -0,0 +1,401 @@
+/*
+ * EAP-TLS/PEAP/TTLS/FAST server common functions
+ * Copyright (c) 2004-2009, Jouni Malinen <j@w1.fi>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * Alternatively, this software may be distributed under the terms of BSD
+ * license.
+ *
+ * See README and COPYING for more details.
+ */
+
+#include "includes.h"
+
+#include "common.h"
+#include "crypto/sha1.h"
+#include "crypto/tls.h"
+#include "eap_i.h"
+#include "eap_tls_common.h"
+
+
+static void eap_server_tls_free_in_buf(struct eap_ssl_data *data);
+
+
+int eap_server_tls_ssl_init(struct eap_sm *sm, struct eap_ssl_data *data,
+ int verify_peer)
+{
+ data->eap = sm;
+ data->phase2 = sm->init_phase2;
+
+ data->conn = tls_connection_init(sm->ssl_ctx);
+ if (data->conn == NULL) {
+ wpa_printf(MSG_INFO, "SSL: Failed to initialize new TLS "
+ "connection");
+ return -1;
+ }
+
+ if (tls_connection_set_verify(sm->ssl_ctx, data->conn, verify_peer)) {
+ wpa_printf(MSG_INFO, "SSL: Failed to configure verification "
+ "of TLS peer certificate");
+ tls_connection_deinit(sm->ssl_ctx, data->conn);
+ data->conn = NULL;
+ return -1;
+ }
+
+ /* TODO: make this configurable */
+ data->tls_out_limit = 1398;
+ if (data->phase2) {
+ /* Limit the fragment size in the inner TLS authentication
+ * since the outer authentication with EAP-PEAP does not yet
+ * support fragmentation */
+ if (data->tls_out_limit > 100)
+ data->tls_out_limit -= 100;
+ }
+ return 0;
+}
+
+
+void eap_server_tls_ssl_deinit(struct eap_sm *sm, struct eap_ssl_data *data)
+{
+ tls_connection_deinit(sm->ssl_ctx, data->conn);
+ eap_server_tls_free_in_buf(data);
+ wpabuf_free(data->tls_out);
+ data->tls_out = NULL;
+}
+
+
+u8 * eap_server_tls_derive_key(struct eap_sm *sm, struct eap_ssl_data *data,
+ char *label, size_t len)
+{
+ struct tls_keys keys;
+ u8 *rnd = NULL, *out;
+
+ out = os_malloc(len);
+ if (out == NULL)
+ return NULL;
+
+ if (tls_connection_prf(sm->ssl_ctx, data->conn, label, 0, out, len) ==
+ 0)
+ return out;
+
+ if (tls_connection_get_keys(sm->ssl_ctx, data->conn, &keys))
+ goto fail;
+
+ if (keys.client_random == NULL || keys.server_random == NULL ||
+ keys.master_key == NULL)
+ goto fail;
+
+ rnd = os_malloc(keys.client_random_len + keys.server_random_len);
+ if (rnd == NULL)
+ goto fail;
+ os_memcpy(rnd, keys.client_random, keys.client_random_len);
+ os_memcpy(rnd + keys.client_random_len, keys.server_random,
+ keys.server_random_len);
+
+ if (tls_prf(keys.master_key, keys.master_key_len,
+ label, rnd, keys.client_random_len +
+ keys.server_random_len, out, len))
+ goto fail;
+
+ os_free(rnd);
+ return out;
+
+fail:
+ os_free(out);
+ os_free(rnd);
+ return NULL;
+}
+
+
+struct wpabuf * eap_server_tls_build_msg(struct eap_ssl_data *data,
+ int eap_type, int version, u8 id)
+{
+ struct wpabuf *req;
+ u8 flags;
+ size_t send_len, plen;
+
+ wpa_printf(MSG_DEBUG, "SSL: Generating Request");
+ if (data->tls_out == NULL) {
+ wpa_printf(MSG_ERROR, "SSL: tls_out NULL in %s", __func__);
+ return NULL;
+ }
+
+ flags = version;
+ send_len = wpabuf_len(data->tls_out) - data->tls_out_pos;
+ if (1 + send_len > data->tls_out_limit) {
+ send_len = data->tls_out_limit - 1;
+ flags |= EAP_TLS_FLAGS_MORE_FRAGMENTS;
+ if (data->tls_out_pos == 0) {
+ flags |= EAP_TLS_FLAGS_LENGTH_INCLUDED;
+ send_len -= 4;
+ }
+ }
+
+ plen = 1 + send_len;
+ if (flags & EAP_TLS_FLAGS_LENGTH_INCLUDED)
+ plen += 4;
+
+ req = eap_msg_alloc(EAP_VENDOR_IETF, eap_type, plen,
+ EAP_CODE_REQUEST, id);
+ if (req == NULL)
+ return NULL;
+
+ wpabuf_put_u8(req, flags); /* Flags */
+ if (flags & EAP_TLS_FLAGS_LENGTH_INCLUDED)
+ wpabuf_put_be32(req, wpabuf_len(data->tls_out));
+
+ wpabuf_put_data(req, wpabuf_head_u8(data->tls_out) + data->tls_out_pos,
+ send_len);
+ data->tls_out_pos += send_len;
+
+ if (data->tls_out_pos == wpabuf_len(data->tls_out)) {
+ wpa_printf(MSG_DEBUG, "SSL: Sending out %lu bytes "
+ "(message sent completely)",
+ (unsigned long) send_len);
+ wpabuf_free(data->tls_out);
+ data->tls_out = NULL;
+ data->tls_out_pos = 0;
+ data->state = MSG;
+ } else {
+ wpa_printf(MSG_DEBUG, "SSL: Sending out %lu bytes "
+ "(%lu more to send)", (unsigned long) send_len,
+ (unsigned long) wpabuf_len(data->tls_out) -
+ data->tls_out_pos);
+ data->state = WAIT_FRAG_ACK;
+ }
+
+ return req;
+}
+
+
+struct wpabuf * eap_server_tls_build_ack(u8 id, int eap_type, int version)
+{
+ struct wpabuf *req;
+
+ req = eap_msg_alloc(EAP_VENDOR_IETF, eap_type, 1, EAP_CODE_REQUEST,
+ id);
+ if (req == NULL)
+ return NULL;
+ wpa_printf(MSG_DEBUG, "SSL: Building ACK");
+ wpabuf_put_u8(req, version); /* Flags */
+ return req;
+}
+
+
+static int eap_server_tls_process_cont(struct eap_ssl_data *data,
+ const u8 *buf, size_t len)
+{
+ /* Process continuation of a pending message */
+ if (len > wpabuf_tailroom(data->tls_in)) {
+ wpa_printf(MSG_DEBUG, "SSL: Fragment overflow");
+ return -1;
+ }
+
+ wpabuf_put_data(data->tls_in, buf, len);
+ wpa_printf(MSG_DEBUG, "SSL: Received %lu bytes, waiting for %lu "
+ "bytes more", (unsigned long) len,
+ (unsigned long) wpabuf_tailroom(data->tls_in));
+
+ return 0;
+}
+
+
+static int eap_server_tls_process_fragment(struct eap_ssl_data *data,
+ u8 flags, u32 message_length,
+ const u8 *buf, size_t len)
+{
+ /* Process a fragment that is not the last one of the message */
+ if (data->tls_in == NULL && !(flags & EAP_TLS_FLAGS_LENGTH_INCLUDED)) {
+ wpa_printf(MSG_DEBUG, "SSL: No Message Length field in a "
+ "fragmented packet");
+ return -1;
+ }
+
+ if (data->tls_in == NULL) {
+ /* First fragment of the message */
+
+ /* Limit length to avoid rogue peers from causing large
+ * memory allocations. */
+ if (message_length > 65536) {
+ wpa_printf(MSG_INFO, "SSL: Too long TLS fragment (size"
+ " over 64 kB)");
+ return -1;
+ }
+
+ data->tls_in = wpabuf_alloc(message_length);
+ if (data->tls_in == NULL) {
+ wpa_printf(MSG_DEBUG, "SSL: No memory for message");
+ return -1;
+ }
+ wpabuf_put_data(data->tls_in, buf, len);
+ wpa_printf(MSG_DEBUG, "SSL: Received %lu bytes in first "
+ "fragment, waiting for %lu bytes more",
+ (unsigned long) len,
+ (unsigned long) wpabuf_tailroom(data->tls_in));
+ }
+
+ return 0;
+}
+
+
+int eap_server_tls_phase1(struct eap_sm *sm, struct eap_ssl_data *data)
+{
+ if (data->tls_out) {
+ /* This should not happen.. */
+ wpa_printf(MSG_INFO, "SSL: pending tls_out data when "
+ "processing new message");
+ wpabuf_free(data->tls_out);
+ WPA_ASSERT(data->tls_out == NULL);
+ }
+
+ data->tls_out = tls_connection_server_handshake(sm->ssl_ctx,
+ data->conn,
+ data->tls_in, NULL);
+ if (data->tls_out == NULL) {
+ wpa_printf(MSG_INFO, "SSL: TLS processing failed");
+ return -1;
+ }
+ if (tls_connection_get_failed(sm->ssl_ctx, data->conn)) {
+ /* TLS processing has failed - return error */
+ wpa_printf(MSG_DEBUG, "SSL: Failed - tls_out available to "
+ "report error");
+ return -1;
+ }
+
+ return 0;
+}
+
+
+static int eap_server_tls_reassemble(struct eap_ssl_data *data, u8 flags,
+ const u8 **pos, size_t *left)
+{
+ unsigned int tls_msg_len = 0;
+ const u8 *end = *pos + *left;
+
+ if (flags & EAP_TLS_FLAGS_LENGTH_INCLUDED) {
+ if (*left < 4) {
+ wpa_printf(MSG_INFO, "SSL: Short frame with TLS "
+ "length");
+ return -1;
+ }
+ tls_msg_len = WPA_GET_BE32(*pos);
+ wpa_printf(MSG_DEBUG, "SSL: TLS Message Length: %d",
+ tls_msg_len);
+ *pos += 4;
+ *left -= 4;
+ }
+
+ wpa_printf(MSG_DEBUG, "SSL: Received packet: Flags 0x%x "
+ "Message Length %u", flags, tls_msg_len);
+
+ if (data->state == WAIT_FRAG_ACK) {
+ if (*left != 0) {
+ wpa_printf(MSG_DEBUG, "SSL: Unexpected payload in "
+ "WAIT_FRAG_ACK state");
+ return -1;
+ }
+ wpa_printf(MSG_DEBUG, "SSL: Fragment acknowledged");
+ return 1;
+ }
+
+ if (data->tls_in &&
+ eap_server_tls_process_cont(data, *pos, end - *pos) < 0)
+ return -1;
+
+ if (flags & EAP_TLS_FLAGS_MORE_FRAGMENTS) {
+ if (eap_server_tls_process_fragment(data, flags, tls_msg_len,
+ *pos, end - *pos) < 0)
+ return -1;
+
+ data->state = FRAG_ACK;
+ return 1;
+ }
+
+ if (data->state == FRAG_ACK) {
+ wpa_printf(MSG_DEBUG, "SSL: All fragments received");
+ data->state = MSG;
+ }
+
+ if (data->tls_in == NULL) {
+ /* Wrap unfragmented messages as wpabuf without extra copy */
+ wpabuf_set(&data->tmpbuf, *pos, end - *pos);
+ data->tls_in = &data->tmpbuf;
+ }
+
+ return 0;
+}
+
+
+static void eap_server_tls_free_in_buf(struct eap_ssl_data *data)
+{
+ if (data->tls_in != &data->tmpbuf)
+ wpabuf_free(data->tls_in);
+ data->tls_in = NULL;
+}
+
+
+struct wpabuf * eap_server_tls_encrypt(struct eap_sm *sm,
+ struct eap_ssl_data *data,
+ const struct wpabuf *plain)
+{
+ struct wpabuf *buf;
+
+ buf = tls_connection_encrypt(sm->ssl_ctx, data->conn,
+ plain);
+ if (buf == NULL) {
+ wpa_printf(MSG_INFO, "SSL: Failed to encrypt Phase 2 data");
+ return NULL;
+ }
+
+ return buf;
+}
+
+
+int eap_server_tls_process(struct eap_sm *sm, struct eap_ssl_data *data,
+ struct wpabuf *respData, void *priv, int eap_type,
+ int (*proc_version)(struct eap_sm *sm, void *priv,
+ int peer_version),
+ void (*proc_msg)(struct eap_sm *sm, void *priv,
+ const struct wpabuf *respData))
+{
+ const u8 *pos;
+ u8 flags;
+ size_t left;
+ int ret, res = 0;
+
+ pos = eap_hdr_validate(EAP_VENDOR_IETF, eap_type, respData, &left);
+ if (pos == NULL || left < 1)
+ return 0; /* Should not happen - frame already validated */
+ flags = *pos++;
+ left--;
+ wpa_printf(MSG_DEBUG, "SSL: Received packet(len=%lu) - Flags 0x%02x",
+ (unsigned long) wpabuf_len(respData), flags);
+
+ if (proc_version &&
+ proc_version(sm, priv, flags & EAP_TLS_VERSION_MASK) < 0)
+ return -1;
+
+ ret = eap_server_tls_reassemble(data, flags, &pos, &left);
+ if (ret < 0) {
+ res = -1;
+ goto done;
+ } else if (ret == 1)
+ return 0;
+
+ if (proc_msg)
+ proc_msg(sm, priv, respData);
+
+ if (tls_connection_get_write_alerts(sm->ssl_ctx, data->conn) > 1) {
+ wpa_printf(MSG_INFO, "SSL: Locally detected fatal error in "
+ "TLS processing");
+ res = -1;
+ }
+
+done:
+ eap_server_tls_free_in_buf(data);
+
+ return res;
+}