openssl/crypto/asn1/asn1_par.c
Pauli 60eba30f60 Memory bounds checking in asn1 code.
Check that sprint, strcpy don't overflow.

Avoid some strlen operations when the previous sprintf return value can be used.

Also fix the undefined behaviour `*(long *)x = y` when x isn't a long or character pointer.
ISO/IEC 9899:1999 6.5/7 for the details.

Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/3869)
2017-07-06 12:59:51 +10:00

376 lines
13 KiB
C

/*
* Copyright 1995-2017 The OpenSSL Project Authors. All Rights Reserved.
*
* Licensed under the OpenSSL license (the "License"). You may not use
* this file except in compliance with the License. You can obtain a copy
* in the file LICENSE in the source distribution or at
* https://www.openssl.org/source/license.html
*/
#include <stdio.h>
#include "internal/cryptlib.h"
#include <openssl/buffer.h>
#include <openssl/objects.h>
#include <openssl/asn1.h>
#ifndef ASN1_PARSE_MAXDEPTH
#define ASN1_PARSE_MAXDEPTH 128
#endif
static int asn1_print_info(BIO *bp, int tag, int xclass, int constructed,
int indent);
static int asn1_parse2(BIO *bp, const unsigned char **pp, long length,
int offset, int depth, int indent, int dump);
static int asn1_print_info(BIO *bp, int tag, int xclass, int constructed,
int indent)
{
static const char fmt[] = "%-18s";
char str[128];
const char *p;
if (constructed & V_ASN1_CONSTRUCTED)
p = "cons: ";
else
p = "prim: ";
if (BIO_write(bp, p, 6) < 6)
goto err;
BIO_indent(bp, indent, 128);
p = str;
if ((xclass & V_ASN1_PRIVATE) == V_ASN1_PRIVATE)
BIO_snprintf(str, sizeof(str), "priv [ %d ] ", tag);
else if ((xclass & V_ASN1_CONTEXT_SPECIFIC) == V_ASN1_CONTEXT_SPECIFIC)
BIO_snprintf(str, sizeof(str), "cont [ %d ]", tag);
else if ((xclass & V_ASN1_APPLICATION) == V_ASN1_APPLICATION)
BIO_snprintf(str, sizeof(str), "appl [ %d ]", tag);
else if (tag > 30)
BIO_snprintf(str, sizeof(str), "<ASN1 %d>", tag);
else
p = ASN1_tag2str(tag);
if (BIO_printf(bp, fmt, p) <= 0)
goto err;
return 1;
err:
return 0;
}
int ASN1_parse(BIO *bp, const unsigned char *pp, long len, int indent)
{
return asn1_parse2(bp, &pp, len, 0, 0, indent, 0);
}
int ASN1_parse_dump(BIO *bp, const unsigned char *pp, long len, int indent,
int dump)
{
return asn1_parse2(bp, &pp, len, 0, 0, indent, dump);
}
static int asn1_parse2(BIO *bp, const unsigned char **pp, long length,
int offset, int depth, int indent, int dump)
{
const unsigned char *p, *ep, *tot, *op, *opp;
long len;
int tag, xclass, ret = 0;
int nl, hl, j, r;
ASN1_OBJECT *o = NULL;
ASN1_OCTET_STRING *os = NULL;
/* ASN1_BMPSTRING *bmp=NULL; */
int dump_indent, dump_cont = 0;
if (depth > ASN1_PARSE_MAXDEPTH) {
BIO_puts(bp, "BAD RECURSION DEPTH\n");
return 0;
}
dump_indent = 6; /* Because we know BIO_dump_indent() */
p = *pp;
tot = p + length;
while (length > 0) {
op = p;
j = ASN1_get_object(&p, &len, &tag, &xclass, length);
if (j & 0x80) {
if (BIO_write(bp, "Error in encoding\n", 18) <= 0)
goto end;
ret = 0;
goto end;
}
hl = (p - op);
length -= hl;
/*
* if j == 0x21 it is a constructed indefinite length object
*/
if (BIO_printf(bp, "%5ld:", (long)offset + (long)(op - *pp))
<= 0)
goto end;
if (j != (V_ASN1_CONSTRUCTED | 1)) {
if (BIO_printf(bp, "d=%-2d hl=%ld l=%4ld ",
depth, (long)hl, len) <= 0)
goto end;
} else {
if (BIO_printf(bp, "d=%-2d hl=%ld l=inf ", depth, (long)hl) <= 0)
goto end;
}
if (!asn1_print_info(bp, tag, xclass, j, (indent) ? depth : 0))
goto end;
if (j & V_ASN1_CONSTRUCTED) {
const unsigned char *sp = p;
ep = p + len;
if (BIO_write(bp, "\n", 1) <= 0)
goto end;
if (len > length) {
BIO_printf(bp, "length is greater than %ld\n", length);
ret = 0;
goto end;
}
if ((j == 0x21) && (len == 0)) {
for (;;) {
r = asn1_parse2(bp, &p, (long)(tot - p),
offset + (p - *pp), depth + 1,
indent, dump);
if (r == 0) {
ret = 0;
goto end;
}
if ((r == 2) || (p >= tot)) {
len = p - sp;
break;
}
}
} else {
long tmp = len;
while (p < ep) {
sp = p;
r = asn1_parse2(bp, &p, tmp,
offset + (p - *pp), depth + 1,
indent, dump);
if (r == 0) {
ret = 0;
goto end;
}
tmp -= p - sp;
}
}
} else if (xclass != 0) {
p += len;
if (BIO_write(bp, "\n", 1) <= 0)
goto end;
} else {
nl = 0;
if ((tag == V_ASN1_PRINTABLESTRING) ||
(tag == V_ASN1_T61STRING) ||
(tag == V_ASN1_IA5STRING) ||
(tag == V_ASN1_VISIBLESTRING) ||
(tag == V_ASN1_NUMERICSTRING) ||
(tag == V_ASN1_UTF8STRING) ||
(tag == V_ASN1_UTCTIME) || (tag == V_ASN1_GENERALIZEDTIME)) {
if (BIO_write(bp, ":", 1) <= 0)
goto end;
if ((len > 0) && BIO_write(bp, (const char *)p, (int)len)
!= (int)len)
goto end;
} else if (tag == V_ASN1_OBJECT) {
opp = op;
if (d2i_ASN1_OBJECT(&o, &opp, len + hl) != NULL) {
if (BIO_write(bp, ":", 1) <= 0)
goto end;
i2a_ASN1_OBJECT(bp, o);
} else {
if (BIO_puts(bp, ":BAD OBJECT") <= 0)
goto end;
dump_cont = 1;
}
} else if (tag == V_ASN1_BOOLEAN) {
if (len != 1) {
if (BIO_puts(bp, ":BAD BOOLEAN") <= 0)
goto end;
dump_cont = 1;
}
if (len > 0)
BIO_printf(bp, ":%u", p[0]);
} else if (tag == V_ASN1_BMPSTRING) {
/* do the BMP thang */
} else if (tag == V_ASN1_OCTET_STRING) {
int i, printable = 1;
opp = op;
os = d2i_ASN1_OCTET_STRING(NULL, &opp, len + hl);
if (os != NULL && os->length > 0) {
opp = os->data;
/*
* testing whether the octet string is printable
*/
for (i = 0; i < os->length; i++) {
if (((opp[i] < ' ') &&
(opp[i] != '\n') &&
(opp[i] != '\r') &&
(opp[i] != '\t')) || (opp[i] > '~')) {
printable = 0;
break;
}
}
if (printable)
/* printable string */
{
if (BIO_write(bp, ":", 1) <= 0)
goto end;
if (BIO_write(bp, (const char *)opp, os->length) <= 0)
goto end;
} else if (!dump)
/*
* not printable => print octet string as hex dump
*/
{
if (BIO_write(bp, "[HEX DUMP]:", 11) <= 0)
goto end;
for (i = 0; i < os->length; i++) {
if (BIO_printf(bp, "%02X", opp[i]) <= 0)
goto end;
}
} else
/* print the normal dump */
{
if (!nl) {
if (BIO_write(bp, "\n", 1) <= 0)
goto end;
}
if (BIO_dump_indent(bp,
(const char *)opp,
((dump == -1 || dump >
os->
length) ? os->length : dump),
dump_indent) <= 0)
goto end;
nl = 1;
}
}
ASN1_OCTET_STRING_free(os);
os = NULL;
} else if (tag == V_ASN1_INTEGER) {
ASN1_INTEGER *bs;
int i;
opp = op;
bs = d2i_ASN1_INTEGER(NULL, &opp, len + hl);
if (bs != NULL) {
if (BIO_write(bp, ":", 1) <= 0)
goto end;
if (bs->type == V_ASN1_NEG_INTEGER)
if (BIO_write(bp, "-", 1) <= 0)
goto end;
for (i = 0; i < bs->length; i++) {
if (BIO_printf(bp, "%02X", bs->data[i]) <= 0)
goto end;
}
if (bs->length == 0) {
if (BIO_write(bp, "00", 2) <= 0)
goto end;
}
} else {
if (BIO_puts(bp, ":BAD INTEGER") <= 0)
goto end;
dump_cont = 1;
}
ASN1_INTEGER_free(bs);
} else if (tag == V_ASN1_ENUMERATED) {
ASN1_ENUMERATED *bs;
int i;
opp = op;
bs = d2i_ASN1_ENUMERATED(NULL, &opp, len + hl);
if (bs != NULL) {
if (BIO_write(bp, ":", 1) <= 0)
goto end;
if (bs->type == V_ASN1_NEG_ENUMERATED)
if (BIO_write(bp, "-", 1) <= 0)
goto end;
for (i = 0; i < bs->length; i++) {
if (BIO_printf(bp, "%02X", bs->data[i]) <= 0)
goto end;
}
if (bs->length == 0) {
if (BIO_write(bp, "00", 2) <= 0)
goto end;
}
} else {
if (BIO_puts(bp, ":BAD ENUMERATED") <= 0)
goto end;
dump_cont = 1;
}
ASN1_ENUMERATED_free(bs);
} else if (len > 0 && dump) {
if (!nl) {
if (BIO_write(bp, "\n", 1) <= 0)
goto end;
}
if (BIO_dump_indent(bp, (const char *)p,
((dump == -1 || dump > len) ? len : dump),
dump_indent) <= 0)
goto end;
nl = 1;
}
if (dump_cont) {
int i;
const unsigned char *tmp = op + hl;
if (BIO_puts(bp, ":[") <= 0)
goto end;
for (i = 0; i < len; i++) {
if (BIO_printf(bp, "%02X", tmp[i]) <= 0)
goto end;
}
if (BIO_puts(bp, "]") <= 0)
goto end;
}
if (!nl) {
if (BIO_write(bp, "\n", 1) <= 0)
goto end;
}
p += len;
if ((tag == V_ASN1_EOC) && (xclass == 0)) {
ret = 2; /* End of sequence */
goto end;
}
}
length -= len;
}
ret = 1;
end:
ASN1_OBJECT_free(o);
ASN1_OCTET_STRING_free(os);
*pp = p;
return ret;
}
const char *ASN1_tag2str(int tag)
{
static const char *const tag2str[] = {
/* 0-4 */
"EOC", "BOOLEAN", "INTEGER", "BIT STRING", "OCTET STRING",
/* 5-9 */
"NULL", "OBJECT", "OBJECT DESCRIPTOR", "EXTERNAL", "REAL",
/* 10-13 */
"ENUMERATED", "<ASN1 11>", "UTF8STRING", "<ASN1 13>",
/* 15-17 */
"<ASN1 14>", "<ASN1 15>", "SEQUENCE", "SET",
/* 18-20 */
"NUMERICSTRING", "PRINTABLESTRING", "T61STRING",
/* 21-24 */
"VIDEOTEXSTRING", "IA5STRING", "UTCTIME", "GENERALIZEDTIME",
/* 25-27 */
"GRAPHICSTRING", "VISIBLESTRING", "GENERALSTRING",
/* 28-30 */
"UNIVERSALSTRING", "<ASN1 29>", "BMPSTRING"
};
if ((tag == V_ASN1_NEG_INTEGER) || (tag == V_ASN1_NEG_ENUMERATED))
tag &= ~0x100;
if (tag < 0 || tag > 30)
return "(unknown)";
return tag2str[tag];
}