github/RRG-Proxmark3
1
0
Fork 0
mirror of https://github.com/RfidResearchGroup/proxmark3.git synced 2025-08-25 07:35:40 -07:00
Code Issues Projects Releases Packages Wiki Activity Actions 4

crc32 ok, ev1/enc channel ok.

Browse source
This commit is contained in:
merlokk 2021-07-09 01:27:28 +03:00
commit 2fde5d90ae
1 changed files with 44 additions and 5 deletions
Download patch file Download diff file Expand all files Collapse all files

49
client/src/mifare/desfiresecurechan.c
View file

@ -67,7 +67,6 @@ static void DesfireSecureChannelEncodeEV1(DesfireContext *ctx, uint8_t cmd, uint
memcpy(&data[1], srcdata, srcdatalen);
uint8_t cmac[DESFIRE_MAX_CRYPTO_BLOCK_SIZE] = {0};
DesfireCryptoCMAC(ctx, data, srcdatalen + 1, cmac);
PrintAndLogEx(INFO, "mac iv: %s", sprint_hex(ctx->IV, 16));
memcpy(dstdata, srcdata, srcdatalen);
if (srcdatalen != 0 && ctx->commMode == DCMMACed) {
@ -148,12 +147,52 @@ static void DesfireSecureChannelDecodeEV1(DesfireContext *ctx, uint8_t *srcdata,
PrintAndLogEx(INFO, " calculated MAC: %s", sprint_hex(cmac, desfire_get_key_block_length(ctx->keyType)));
}
} else if (ctx->commMode == DCMEncrypted) {
//mifare_cypher_blocks_chained(tag, NULL, NULL, res, *nbytes, MCD_RECEIVE, MCO_DECYPHER);
PrintAndLogEx(INFO, "data: %s", sprint_hex(srcdata, srcdatalen));
PrintAndLogEx(INFO, "dec iv: %s", sprint_hex(ctx->IV, 16));
if (srcdatalen < desfire_get_key_block_length(ctx->keyType)) {
memcpy(dstdata, srcdata, srcdatalen);
*dstdatalen = srcdatalen;
return;
}
DesfireCryptoEncDec(ctx, true, srcdata, srcdatalen, dstdata, false);
PrintAndLogEx(INFO, "dec iv: %s", sprint_hex(ctx->IV, 16));
PrintAndLogEx(INFO, "decoded[%d]: %s", srcdatalen, sprint_hex(dstdata, srcdatalen));
size_t crcpos = srcdatalen - 1;
while (crcpos > 0)
if (dstdata[crcpos] == 0)
crcpos--;
else
break;
crcpos++; // crc may be 0x00000000
*dstdatalen = crcpos;
PrintAndLogEx(INFO, "crcpos: %d", crcpos);
if (crcpos < 4) {
PrintAndLogEx(WARNING, "No space for crc. pos: %d", crcpos);
return;
}
uint8_t crcdata[1024] = {0};
bool crcok = false;
for (int i = 0; i < 5; i++) {
if (crcpos == 0)
break;
if (crcpos - i + 4 > srcdatalen)
continue;
memcpy(crcdata, dstdata, crcpos - i);
crcdata[crcpos - i] = respcode;
if (desfire_crc32_check(crcdata, crcpos - i + 1, &dstdata[crcpos - i])) {
crcpos -= i;
crcok = true;
break;
}
}
if (crcok) {
*dstdatalen = crcpos;
} else {
PrintAndLogEx(WARNING, "CRC32 error. pos: %d", crcpos);
}
} else {
memcpy(dstdata, srcdata, srcdatalen);
*dstdatalen = srcdatalen;