encode with padding sketch

This commit is contained in:
merlokk 2021-08-04 20:01:11 +03:00
commit e78c563e45
5 changed files with 19 additions and 9 deletions

View file

@ -2628,14 +2628,12 @@ static int CmdHF14ADesSetConfiguration(const char *Cmd) {
return res;
}
DesfireSetCommMode(&dctx, DCMEncryptedPlain);
res = DesfireSetConfiguration(&dctx, paramid, param, paramlen);
if (res == PM3_SUCCESS) {
PrintAndLogEx(SUCCESS, "Set configuration 0x%02x " _GREEN_("ok") " ", paramid);
} else {
PrintAndLogEx(FAILED, "Set configuration 0x%02x " _RED_("failed") " ", paramid);
}
DesfireSetCommMode(&dctx, DCMEncrypted);
DropField();
return res;

View file

@ -2545,7 +2545,7 @@ int DesfireSetConfiguration(DesfireContext *dctx, uint8_t paramid, uint8_t *para
size_t datalen = 1 + paramlen;
// add crc
/*// add crc
if (dctx->secureChannel == DACd40) {
iso14443a_crc_append(&data[1], datalen - 1);
datalen += 2;
@ -2553,11 +2553,12 @@ int DesfireSetConfiguration(DesfireContext *dctx, uint8_t paramid, uint8_t *para
desfire_crc32_append(cdata, datalen + 1);
datalen += 4;
}
*/
// dynamic length
if (paramid == 0x02) {
data[datalen] = 0x80;
datalen++;
if (paramid == 0x02 && dctx->commMode == DCMEncrypted) {
dctx->commMode = DCMEncryptedWithPadding;
//data[datalen] = 0x80;
//datalen++;
}
// send command

View file

@ -429,6 +429,7 @@ uint8_t DesfireCommModeToFileCommMode(DesfireCommunicationMode comm_mode) {
fmode = 0x01;
break;
case DCMEncrypted:
case DCMEncryptedWithPadding:
case DCMEncryptedPlain:
fmode = 0x11;
break;

View file

@ -58,6 +58,7 @@ typedef enum {
DCMPlain,
DCMMACed,
DCMEncrypted,
DCMEncryptedWithPadding,
DCMEncryptedPlain
} DesfireCommunicationMode;

View file

@ -260,16 +260,24 @@ static void DesfireSecureChannelEncodeEV1(DesfireContext *ctx, uint8_t cmd, uint
memcpy(&dstdata[srcdatalen], cmac, DesfireGetMACLength(ctx));
*dstdatalen = srcdatalen + DesfireGetMACLength(ctx);
}
} else if (ctx->commMode == DCMEncrypted) {
rlen = padded_data_length(srcdatalen + 4 - hdrlen, desfire_get_key_block_length(ctx->keyType));
} else if (ctx->commMode == DCMEncrypted || ctx->commMode == DCMEncryptedWithPadding) {
uint8_t paddinglen = (ctx->commMode == DCMEncryptedWithPadding) ? 1 : 0;
rlen = padded_data_length(srcdatalen + 4 + paddinglen - hdrlen, desfire_get_key_block_length(ctx->keyType));
data[0] = cmd;
// crc
memcpy(&data[1], srcdata, srcdatalen);
desfire_crc32_append(data, srcdatalen + 1);
// add padding
if (paddinglen > 0)
data[srcdatalen + 1 + 4] = 0x80;
memcpy(dstdata, srcdata, hdrlen);
DesfireCryptoEncDec(ctx, DCOSessionKeyEnc, &data[1 + hdrlen], rlen, &dstdata[hdrlen], true);
*dstdatalen = hdrlen + rlen;
ctx->commMode = DCMEncrypted;
} else if (ctx->commMode == DCMEncryptedPlain) {
if (srcdatalen <= hdrlen)
return;
@ -374,6 +382,7 @@ static void DesfireSecureChannelDecodeD40(DesfireContext *ctx, uint8_t *srcdata,
break;
}
case DCMEncrypted:
case DCMEncryptedWithPadding:
if (srcdatalen < desfire_get_key_block_length(ctx->keyType)) {
memcpy(dstdata, srcdata, srcdatalen);
*dstdatalen = srcdatalen;