| 1 | //----------------------------------------------------------------------------- |
| 2 | // Copyright (C) 2018 Merlok |
| 3 | // |
| 4 | // This code is licensed to you under the terms of the GNU GPL, version 2 or, |
| 5 | // at your option, any later version. See the LICENSE.txt file for the text of |
| 6 | // the license. |
| 7 | //----------------------------------------------------------------------------- |
| 8 | // asn.1 utils |
| 9 | //----------------------------------------------------------------------------- |
| 10 | |
| 11 | #include "asn1utils.h" |
| 12 | #include <ctype.h> |
| 13 | #include <stdlib.h> |
| 14 | #include <mbedtls/asn1.h> |
| 15 | #include "emv/tlv.h" |
| 16 | #include "emv/dump.h" |
| 17 | #include "asn1dump.h" |
| 18 | #include "util.h" |
| 19 | #include "ui.h" // PrintAndLog |
| 20 | |
| 21 | int ecdsa_asn1_get_signature(uint8_t *signature, size_t signaturelen, uint8_t *rval, uint8_t *sval) { |
| 22 | if (!signature || !signaturelen || !rval || !sval) |
| 23 | return 1; |
| 24 | |
| 25 | int res = 0; |
| 26 | unsigned char *p = signature; |
| 27 | const unsigned char *end = p + signaturelen; |
| 28 | size_t len; |
| 29 | mbedtls_mpi xmpi; |
| 30 | |
| 31 | if ((res = mbedtls_asn1_get_tag(&p, end, &len, MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE)) == 0) { |
| 32 | mbedtls_mpi_init(&xmpi); |
| 33 | res = mbedtls_asn1_get_mpi(&p, end, &xmpi); |
| 34 | if (res) { |
| 35 | mbedtls_mpi_free(&xmpi); |
| 36 | goto exit; |
| 37 | } |
| 38 | |
| 39 | res = mbedtls_mpi_write_binary(&xmpi, rval, 32); |
| 40 | mbedtls_mpi_free(&xmpi); |
| 41 | if (res) |
| 42 | goto exit; |
| 43 | |
| 44 | mbedtls_mpi_init(&xmpi); |
| 45 | res = mbedtls_asn1_get_mpi(&p, end, &xmpi); |
| 46 | if (res) { |
| 47 | mbedtls_mpi_free(&xmpi); |
| 48 | goto exit; |
| 49 | } |
| 50 | |
| 51 | res = mbedtls_mpi_write_binary(&xmpi, sval, 32); |
| 52 | mbedtls_mpi_free(&xmpi); |
| 53 | if (res) |
| 54 | goto exit; |
| 55 | |
| 56 | // check size |
| 57 | if (end != p) |
| 58 | return 2; |
| 59 | } |
| 60 | |
| 61 | exit: |
| 62 | return res; |
| 63 | } |
| 64 | |
| 65 | static bool print_cb(void *data, const struct tlv *tlv, int level, bool is_leaf) { |
| 66 | bool candump = true; |
| 67 | asn1_tag_dump(tlv, stdout, level, &candump); |
| 68 | if (is_leaf && candump) { |
| 69 | dump_buffer(tlv->value, tlv->len, stdout, level); |
| 70 | } |
| 71 | |
| 72 | return true; |
| 73 | } |
| 74 | |
| 75 | int asn1_print(uint8_t *asn1buf, size_t asn1buflen, char *indent) { |
| 76 | |
| 77 | struct tlvdb *t = NULL; |
| 78 | t = tlvdb_parse_multi(asn1buf, asn1buflen); |
| 79 | if (t) { |
| 80 | tlvdb_visit(t, print_cb, NULL, 0); |
| 81 | tlvdb_free(t); |
| 82 | } else { |
| 83 | PrintAndLogEx(ERR, "Can't parse data as TLV tree."); |
| 84 | return 1; |
| 85 | } |
| 86 | |
| 87 | return 0; |
| 88 | } |
| 89 | |
| 90 | |