+/* HomeMatic protocol-functions
+ *
+ * Copyright (c) 2014-15 Michael Gernoth <michael@gernoth.net>
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to
+ * deal in the Software without restriction, including without limitation the
+ * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
+ * sell copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
+ * IN THE SOFTWARE.
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+#include <stdint.h>
+#include <string.h>
+#include <strings.h>
+#include <errno.h>
+#include <sys/types.h>
+#include <sys/time.h>
+
+#include "aes.h"
+#include "hexdump.h"
+#include "hm.h"
+
+static int debug = 0;
+
+uint8_t* hm_sign(uint8_t *key, uint8_t *challenge, uint8_t *m_frame, uint8_t *exp_auth, uint8_t *resp)
+{
+ uint8_t signkey[16];
+ WORD ks[60];
+ struct timeval tv;
+ int i;
+
+ printf("AES-request with challenge: %02x%02x%02x%02x%02x%02x\n",
+ challenge[0], challenge[1], challenge[2],
+ challenge[3], challenge[4], challenge[5]);
+
+ /*
+ * Build signing key by XORing the first 6 bytes of
+ * the key with the challenge.
+ */
+ memcpy(signkey, key, sizeof(signkey));
+ for (i = 0; i < 6; i++) {
+ signkey[i] ^= challenge[i];
+ }
+ aes_key_setup(signkey, ks, 128);
+
+ /*
+ * Generate payload for first encryption.
+ */
+ gettimeofday(&tv, NULL);
+ resp[0] = tv.tv_sec >> 24 & 0xff;
+ resp[1] = tv.tv_sec >> 16 & 0xff;
+ resp[2] = tv.tv_sec >> 8 & 0xff;
+ resp[3] = tv.tv_sec & 0xff;
+ resp[4] = tv.tv_usec >> 8 & 0xff;
+ resp[5] = tv.tv_usec & 0xff;
+ memcpy(&(resp[6]), &(m_frame[MSGID]), 10);
+
+ if (debug)
+ hexdump(resp, 16, "P > ");
+
+ aes_encrypt(resp, resp, ks, 128);
+
+ if (debug)
+ hexdump(resp, 16, "Pe > ");
+
+ /*
+ * Device has to answer with the first 4 bytes of the
+ * encrypted payload to authenticate, so pass them to
+ * the caller.
+ */
+
+ if (exp_auth) {
+ memcpy(exp_auth, resp, 4);
+ }
+
+ /*
+ * XOR parameters of the m_frame to the payload.
+ */
+ for (i = 0; i < PAYLOADLEN(m_frame) - 1; i++) {
+ if (i == 16) {
+ break;
+ }
+
+ resp[i] ^= m_frame[PAYLOAD + 1+ i];
+ }
+
+ if (debug)
+ hexdump(resp, 16, "Pe^ > ");
+
+ /*
+ * Encrypt payload again
+ */
+ aes_encrypt(resp, resp, ks, 128);
+
+ if (debug)
+ hexdump(resp, 16, "Pe^e> ");
+
+ return resp;
+}
projects / hmcfgusb / commitdiff