proxmark3/client/crypto/asn1dump.c
Fl0-0 994f21fe01 Fix format-truncation warning, missing string.h inclusion and strnlen warning (#723)
* Fix format-truncation warning, missing string.h inclusion and strnlen warning

* Dynamic string width field
2018-11-30 09:03:44 +01:00

357 lines
8.5 KiB
C

//-----------------------------------------------------------------------------
// 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 dumping
//-----------------------------------------------------------------------------
#define _POSIX_C_SOURCE 200809L // need for strnlen()
#include "asn1dump.h"
#include <ctype.h>
#include <stdlib.h>
#include <unistd.h>
#include <stdio.h>
#include <string.h>
#include <jansson.h>
#include <mbedtls/asn1.h>
#include <mbedtls/oid.h>
#include "emv/emv_tags.h"
#include "emv/dump.h"
#include "emv/emvjson.h"
#include "util.h"
#include "proxmark3.h"
#define PRINT_INDENT(level) {for (int i = 0; i < (level); i++) fprintf(f, " ");}
enum asn1_tag_t {
ASN1_TAG_GENERIC,
ASN1_TAG_BOOLEAN,
ASN1_TAG_INTEGER,
ASN1_TAG_STRING,
ASN1_TAG_OCTET_STRING,
ASN1_TAG_UTC_TIME,
ASN1_TAG_STR_TIME,
ASN1_TAG_OBJECT_ID,
};
struct asn1_tag {
tlv_tag_t tag;
char *name;
enum asn1_tag_t type;
const void *data;
};
static const struct asn1_tag asn1_tags[] = {
// internal
{ 0x00 , "Unknown ???" },
// ASN.1
{ 0x01, "BOOLEAN", ASN1_TAG_BOOLEAN },
{ 0x02, "INTEGER", ASN1_TAG_INTEGER },
{ 0x03, "BIT STRING" },
{ 0x04, "OCTET STRING", ASN1_TAG_OCTET_STRING},
{ 0x05, "NULL" },
{ 0x06, "OBJECT IDENTIFIER", ASN1_TAG_OBJECT_ID },
{ 0x07, "OBJECT DESCRIPTOR" },
{ 0x08, "EXTERNAL" },
{ 0x09, "REAL" },
{ 0x0A, "ENUMERATED" },
{ 0x0B, "EMBEDDED_PDV" },
{ 0x0C, "UTF8String", ASN1_TAG_STRING },
{ 0x10, "SEQUENCE" },
{ 0x11, "SET" },
{ 0x12, "NumericString", ASN1_TAG_STRING },
{ 0x13, "PrintableString", ASN1_TAG_STRING },
{ 0x14, "T61String" },
{ 0x15, "VideotexString" },
{ 0x16, "IA5String" },
{ 0x17, "UTCTime", ASN1_TAG_UTC_TIME },
{ 0x18, "GeneralizedTime", ASN1_TAG_STR_TIME },
{ 0x19, "GraphicString" },
{ 0x1A, "VisibleString", ASN1_TAG_STRING },
{ 0x1B, "GeneralString", ASN1_TAG_STRING },
{ 0x1C, "UniversalString", ASN1_TAG_STRING },
{ 0x1E, "BMPString" },
{ 0x30, "SEQUENCE" },
{ 0x31, "SET" },
{ 0xa0, "[0]" },
{ 0xa1, "[1]" },
{ 0xa2, "[2]" },
{ 0xa3, "[3]" },
{ 0xa4, "[4]" },
{ 0xa5, "[5]" },
};
static int asn1_sort_tag(tlv_tag_t tag) {
return (int)(tag >= 0x100 ? tag : tag << 8);
}
static int asn1_tlv_compare(const void *a, const void *b) {
const struct tlv *tlv = a;
const struct asn1_tag *tag = b;
return asn1_sort_tag(tlv->tag) - (asn1_sort_tag(tag->tag));
}
static const struct asn1_tag *asn1_get_tag(const struct tlv *tlv) {
struct asn1_tag *tag = bsearch(tlv, asn1_tags, sizeof(asn1_tags) / sizeof(asn1_tags[0]),
sizeof(asn1_tags[0]), asn1_tlv_compare);
return tag ? tag : &asn1_tags[0];
}
static void asn1_tag_dump_str_time(const struct tlv *tlv, const struct asn1_tag *tag, FILE *f, int level, bool longyear, bool *needdump){
int len = tlv->len;
*needdump = false;
int startindx = longyear ? 4 : 2;
if (len > 4) {
fprintf(f, "\tvalue: '");
while (true) {
// year
if (!longyear)
fprintf(f, "20");
fwrite(tlv->value, 1, longyear ? 4 : 2, f);
fprintf(f, "-");
if (len < startindx + 2)
break;
// month
fwrite(&tlv->value[startindx], 1, 2, f);
fprintf(f, "-");
if (len < startindx + 4)
break;
// day
fwrite(&tlv->value[startindx + 2], 1, 2, f);
fprintf(f, " ");
if (len < startindx + 6)
break;
// hour
fwrite(&tlv->value[startindx + 4], 1, 2, f);
fprintf(f, ":");
if (len < startindx + 8)
break;
// min
fwrite(&tlv->value[startindx + 6], 1, 2, f);
fprintf(f, ":");
if (len < startindx + 10)
break;
// sec
fwrite(&tlv->value[startindx + 8], 1, 2, f);
if (len < startindx + 11)
break;
// time zone
fprintf(f, " zone: %.*s", len - 10 - (longyear ? 4 : 2), &tlv->value[startindx + 10]);
break;
}
fprintf(f, "'\n");
} else {
fprintf(f, "\n");
*needdump = true;
}
}
static void asn1_tag_dump_string(const struct tlv *tlv, const struct asn1_tag *tag, FILE *f, int level){
fprintf(f, "\tvalue: '");
fwrite(tlv->value, 1, tlv->len, f);
fprintf(f, "'\n");
}
static void asn1_tag_dump_octet_string(const struct tlv *tlv, const struct asn1_tag *tag, FILE *f, int level, bool *needdump){
*needdump = false;
for (int i = 0; i < tlv->len; i++)
if (!isspace(tlv->value[i]) && !isprint(tlv->value[i])){
*needdump = true;
break;
}
if (*needdump) {
fprintf(f, "'\n");
} else {
fprintf(f, "\t\t");
asn1_tag_dump_string(tlv, tag, f, level);
}
}
static unsigned long asn1_value_integer(const struct tlv *tlv, unsigned start, unsigned end) {
unsigned long ret = 0;
int i;
if (end > tlv->len * 2)
return ret;
if (start >= end)
return ret;
if (start & 1) {
ret += tlv->value[start/2] & 0xf;
i = start + 1;
} else
i = start;
for (; i < end - 1; i += 2) {
ret *= 10;
ret += tlv->value[i/2] >> 4;
ret *= 10;
ret += tlv->value[i/2] & 0xf;
}
if (end & 1) {
ret *= 10;
ret += tlv->value[end/2] >> 4;
}
return ret;
}
static void asn1_tag_dump_boolean(const struct tlv *tlv, const struct asn1_tag *tag, FILE *f, int level) {
PRINT_INDENT(level);
if (tlv->len > 0) {
fprintf(f, "\tvalue: %s\n", tlv->value[0]?"true":"false");
} else {
fprintf(f, "n/a\n");
}
}
static void asn1_tag_dump_integer(const struct tlv *tlv, const struct asn1_tag *tag, FILE *f, int level) {
PRINT_INDENT(level);
if (tlv->len == 4) {
int32_t val = 0;
for (int i = 0; i < tlv->len; i++)
val = (val << 8) + tlv->value[i];
fprintf(f, "\tvalue4b: %d\n", val);
return;
}
fprintf(f, "\tvalue: %lu\n", asn1_value_integer(tlv, 0, tlv->len * 2));
}
static char *asn1_oid_description(const char *oid, bool with_group_desc) {
json_error_t error;
json_t *root = NULL;
char fname[300] = {0};
static char res[300];
memset(res, 0x00, sizeof(res));
strcpy(fname, get_my_executable_directory());
strcat(fname, "crypto/oids.json");
if (access(fname, F_OK) < 0) {
strcpy(fname, get_my_executable_directory());
strcat(fname, "oids.json");
if (access(fname, F_OK) < 0) {
goto error; // file not found
}
}
// load `oids.json`
root = json_load_file(fname, 0, &error);
if (!root || !json_is_object(root)) {
goto error;
}
json_t *elm = json_object_get(root, oid);
if (!elm) {
goto error;
}
if (JsonLoadStr(elm, "$.d", res))
goto error;
char strext[300] = {0};
if (!JsonLoadStr(elm, "$.c", strext)) {
strcat(res, " (");
strcat(res, strext);
strcat(res, ")");
}
json_decref(root);
return res;
error:
if (root)
json_decref(root);
return NULL;
}
static void asn1_tag_dump_object_id(const struct tlv *tlv, const struct asn1_tag *tag, FILE *f, int level) {
PRINT_INDENT(level);
mbedtls_asn1_buf asn1_buf;
asn1_buf.len = tlv->len;
asn1_buf.p = (uint8_t *)tlv->value;
char pstr[300];
mbedtls_oid_get_numeric_string(pstr, sizeof(pstr), &asn1_buf);
fprintf(f, " %s", pstr);
char *jsondesc = asn1_oid_description(pstr, true);
if (jsondesc) {
fprintf(f, " - %s", jsondesc);
} else {
const char *ppstr;
mbedtls_oid_get_attr_short_name(&asn1_buf, &ppstr);
if (ppstr && strnlen(ppstr, 1)) {
fprintf(f, " (%s)\n", ppstr);
return;
}
mbedtls_oid_get_sig_alg_desc(&asn1_buf, &ppstr);
if (ppstr && strnlen(ppstr, 1)) {
fprintf(f, " (%s)\n", ppstr);
return;
}
mbedtls_oid_get_extended_key_usage(&asn1_buf, &ppstr);
if (ppstr && strnlen(ppstr, 1)) {
fprintf(f, " (%s)\n", ppstr);
return;
}
}
fprintf(f, "\n");
}
bool asn1_tag_dump(const struct tlv *tlv, FILE *f, int level, bool *candump) {
if (!tlv) {
fprintf(f, "NULL\n");
return false;
}
const struct asn1_tag *tag = asn1_get_tag(tlv);
PRINT_INDENT(level);
fprintf(f, "--%2hx[%02zx] '%s':", tlv->tag, tlv->len, tag->name);
switch (tag->type) {
case ASN1_TAG_GENERIC:
fprintf(f, "\n");
break;
case ASN1_TAG_STRING:
asn1_tag_dump_string(tlv, tag, f, level);
*candump = false;
break;
case ASN1_TAG_OCTET_STRING:
asn1_tag_dump_octet_string(tlv, tag, f, level, candump);
break;
case ASN1_TAG_BOOLEAN:
asn1_tag_dump_boolean(tlv, tag, f, level);
*candump = false;
break;
case ASN1_TAG_INTEGER:
asn1_tag_dump_integer(tlv, tag, f, level);
*candump = false;
break;
case ASN1_TAG_UTC_TIME:
asn1_tag_dump_str_time(tlv, tag, f, level, false, candump);
break;
case ASN1_TAG_STR_TIME:
asn1_tag_dump_str_time(tlv, tag, f, level, true, candump);
break;
case ASN1_TAG_OBJECT_ID:
asn1_tag_dump_object_id(tlv, tag, f, level);
*candump = false;
break;
};
return true;
}