proxmark3/client/crypto/asn1utils.c

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//-----------------------------------------------------------------------------
// Copyright (C) 2018 Merlok
//
// This code is licensed to you under the terms of the GNU GPL, version 2 or,
// at your option, any later version. See the LICENSE.txt file for the text of
// the license.
//-----------------------------------------------------------------------------
// asn.1 utils
//-----------------------------------------------------------------------------
#include "asn1utils.h"
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#include <ctype.h>
#include <stdlib.h>
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#include <mbedtls/asn1.h>
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#include "emv/tlv.h"
#include "emv/dump.h"
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#include "asn1dump.h"
#include "util.h"
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int ecdsa_asn1_get_signature(uint8_t *signature, size_t signaturelen, uint8_t *rval, uint8_t *sval) {
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if (!signature || !signaturelen || !rval || !sval)
return 1;
int res = 0;
unsigned char *p = signature;
const unsigned char *end = p + signaturelen;
size_t len;
mbedtls_mpi xmpi;
if ((res = mbedtls_asn1_get_tag(&p, end, &len, MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE)) == 0) {
mbedtls_mpi_init(&xmpi);
res = mbedtls_asn1_get_mpi(&p, end, &xmpi);
if (res) {
mbedtls_mpi_free(&xmpi);
goto exit;
}
res = mbedtls_mpi_write_binary(&xmpi, rval, 32);
mbedtls_mpi_free(&xmpi);
if (res)
goto exit;
mbedtls_mpi_init(&xmpi);
res = mbedtls_asn1_get_mpi(&p, end, &xmpi);
if (res) {
mbedtls_mpi_free(&xmpi);
goto exit;
}
res = mbedtls_mpi_write_binary(&xmpi, sval, 32);
mbedtls_mpi_free(&xmpi);
if (res)
goto exit;
// check size
if (end != p)
return 2;
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}
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exit:
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return res;
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}
static bool print_cb(void *data, const struct tlv *tlv, int level, bool is_leaf) {
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bool candump = true;
asn1_tag_dump(tlv, stdout, level, &candump);
if (is_leaf && candump) {
dump_buffer(tlv->value, tlv->len, stdout, level);
}
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return true;
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}
int asn1_print(uint8_t *asn1buf, size_t asn1buflen, const char *indent) {
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struct tlvdb *t = tlvdb_parse_multi(asn1buf, asn1buflen);
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if (t) {
tlvdb_visit(t, print_cb, NULL, 0);
tlvdb_free(t);
} else {
PrintAndLogEx(ERR, "Can't parse data as TLV tree.");
return 1;
}
return 0;
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}