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emrtd: Remove unnecessary memcpys from two dump functions

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Ave 2020-12-18 04:26:39 +03:00
parent 79e9875b43
commit 9b4e0c212f
1 changed files with 9 additions and 14 deletions
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23
client/src/cmdhfemrtd.c
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@ -711,18 +711,17 @@ static bool emrtd_select_and_read(uint8_t *dataout, int *dataoutlen, const char
}
static bool emrtd_dump_ef_dg2(uint8_t *file_contents, int file_length) {
uint8_t data[EMRTD_MAX_FILE_SIZE];
int datalen = 0;
int offset, datalen = 0;
// This is a hacky impl that just looks for the image header. I'll improve it eventually.
// based on mrpkey.py
// FF D8 FF E0 -> JPEG
// 00 00 00 0C 6A 50 -> JPEG 2000
for (int i = 0; i < file_length - 6; i++) {
if ((file_contents[i] == 0xFF && file_contents[i + 1] == 0xD8 && file_contents[i + 2] == 0xFF && file_contents[i + 3] == 0xE0) ||
(file_contents[i] == 0x00 && file_contents[i + 1] == 0x00 && file_contents[i + 2] == 0x00 && file_contents[i + 3] == 0x0C && file_contents[i + 4] == 0x6A && file_contents[i + 5] == 0x50)) {
datalen = file_length - i;
memcpy(data, file_contents + i, datalen);
// Note: Doing file_length - 6 to account for the longest data we're checking.
for (offset = 0; offset < file_length - 6; offset++) {
if ((file_contents[offset] == 0xFF && file_contents[offset + 1] == 0xD8 && file_contents[offset + 2] == 0xFF && file_contents[offset + 3] == 0xE0) ||
(file_contents[offset] == 0x00 && file_contents[offset + 1] == 0x00 && file_contents[offset + 2] == 0x00 && file_contents[offset + 3] == 0x0C && file_contents[offset + 4] == 0x6A && file_contents[offset + 5] == 0x50)) {
datalen = file_length - offset;
break;
}
}
@ -732,7 +731,7 @@ static bool emrtd_dump_ef_dg2(uint8_t *file_contents, int file_length) {
return false;
}
saveFile("EF_DG2", ".jpg", data, datalen);
saveFile("EF_DG2", ".jpg", file_contents + offset, datalen);
return true;
}
@ -756,19 +755,15 @@ static bool emrtd_dump_ef_dg5(uint8_t *file_contents, int file_length) {
}
static bool emrtd_dump_ef_sod(uint8_t *file_contents, int file_length) {
uint8_t data[EMRTD_MAX_FILE_SIZE];
int fieldlen = emrtd_get_asn1_field_length(file_contents, file_length, 1);
int datalen = emrtd_get_asn1_data_length(file_contents, file_length, 1);
if (fieldlen + 1 < EMRTD_MAX_FILE_SIZE) {
memcpy(data, file_contents + fieldlen + 1, datalen);
} else {
if (fieldlen + 1 > EMRTD_MAX_FILE_SIZE) {
PrintAndLogEx(ERR, "error (emrtd_dump_ef_sod) fieldlen out-of-bounds");
return false;
}
saveFile("EF_SOD", ".p7b", data, datalen);
saveFile("EF_SOD", ".p7b", file_contents + fieldlen + 1, datalen);
return true;
}