108 lines
3.0 KiB
C
108 lines
3.0 KiB
C
#include "ch32v30x_rtc.h"
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#include "meshcore/meshframing.h"
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#include "meshcore/packetstructs.h"
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#include "group.h"
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#include "lib/config.h"
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#include "util/hexdump.h"
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#include "util/log.h"
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#include "string.h"
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#define TAG "GroupMessage"
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void sendGroupMessage (GroupTextMessage msg) {
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msg.channelHash = persistent.aesKeys[msg.keyIndex][0];
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msg.flags = 0;
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msg.timestamp = RTC_GetCounter();
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FrameStruct frame;
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frame.header = ROUTE_TYPE_FLOOD | PAYLOAD_TYPE_GRP_TXT | PAYLOAD_VERSION_0;
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frame.path.pathLen = 0;
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size_t offset = 0;
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memset (frame.payload, 0, sizeof (frame.payload));
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frame.payload[offset++] = msg.channelHash;
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uint8_t cipherBuf[176];
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size_t offset2 = 0;
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memcpy (cipherBuf, (const void *)&(msg.timestamp), 4);
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offset2 += 4;
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cipherBuf[offset2++] = msg.flags;
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size_t textSize = offset2 + strlen ((const char *)msg.text);
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if (textSize > 175) {
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textSize = 175;
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}
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memcpy (cipherBuf + offset2, msg.text, textSize);
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offset2 += textSize;
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size_t olen = 0;
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hexdump ("TxDumpDec", cipherBuf, offset2);
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encrypt_then_mac (&(persistent.aesKeys[msg.keyIndex][1]), 16, cipherBuf, offset2, &(frame.payload[offset]), &olen);
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frame.payloadLen = olen + 1;
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sendFrame (frame);
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return;
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}
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void makeSendGroupMessage (char *txt, uint8_t keyIndex) {
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GroupTextMessage msg;
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strcpy((char *) msg.text, persistent.nodeName);
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strcat ((char *)msg.text, ": ");
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strcat ((char *)msg.text, txt);
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msg.keyIndex = keyIndex;
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sendGroupMessage (msg);
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return;
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}
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GroupTextMessage decodeGroupMessage (FrameStruct frame) {
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GroupTextMessage msg;
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memset (&msg, 0, sizeof (msg));
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if ((frame.header & PAYLOAD_TYPE_MASK) != PAYLOAD_TYPE_GRP_TXT) {
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ESP_LOGW (TAG, "Not a group text");
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return msg;
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}
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unsigned char index = 0;
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msg.channelHash = frame.payload[index++];
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unsigned char tmp[184];
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unsigned char decrypted = 0;
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for (unsigned char i = 0; i < AESKeyCount; i++) {
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if (msg.channelHash != persistent.aesKeys[i][0]) {
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ESP_LOGW (TAG, "Hash %d does not equal %d", persistent.aesKeys[i][0], msg.channelHash);
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continue;
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}
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ESP_LOGW (TAG, "Hash does equal %d", msg.channelHash);
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if (mac_then_decrypt (persistent.aesKeys[i] + 1, 16, frame.payload + index, frame.payloadLen - index, tmp) != 0) {
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ESP_LOGW (TAG, "HMAC failed on grouphash key %d not matching %d", persistent.aesKeys[i][0], msg.channelHash);
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continue;
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}
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hexdump ("RxDumpDec", tmp, frame.payloadLen - index);
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decrypted = 1;
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break;
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}
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if (!decrypted) {
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return msg;
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}
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unsigned char plaintextLen = frame.payloadLen - index;
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index = 0;
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memcpy (&msg.timestamp, tmp + index, 4);
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index += 4;
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msg.flags = tmp[index++];
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memcpy (msg.text, tmp + index, plaintextLen - index);
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return msg;
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}
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void printGroupMessage (GroupTextMessage msg) {
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printf ("Message with channel hash %d, flags %d: %s\n", msg.channelHash,
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msg.flags, msg.text);
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} |