730 lines
17 KiB
C
730 lines
17 KiB
C
/*
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* Copyright (c) 1997 - 2007 Kungliga Tekniska Högskolan
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* (Royal Institute of Technology, Stockholm, Sweden).
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* All rights reserved.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions
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* are met:
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*
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* 1. Redistributions of source code must retain the above copyright
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* notice, this list of conditions and the following disclaimer.
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*
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* 2. Redistributions in binary form must reproduce the above copyright
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* notice, this list of conditions and the following disclaimer in the
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* documentation and/or other materials provided with the distribution.
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*
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* 3. Neither the name of the Institute nor the names of its contributors
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* may be used to endorse or promote products derived from this software
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* without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
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* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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* ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
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* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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* SUCH DAMAGE.
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*/
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#include "der_locl.h"
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/*
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* All decoding functions take a pointer `p' to first position in
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* which to read, from the left, `len' which means the maximum number
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* of characters we are able to read, `ret' were the value will be
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* returned and `size' where the number of used bytes is stored.
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* Either 0 or an error code is returned.
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*/
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int ASN1CALL
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der_get_unsigned (const unsigned char *p, size_t len,
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unsigned *ret, size_t *size)
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{
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unsigned val = 0;
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size_t oldlen = len;
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if (len == sizeof(val) + 1 && p[0] == 0)
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;
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else if (len > sizeof(val))
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return ASN1_OVERRUN;
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while (len--)
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val = val * 256 + *p++;
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*ret = val;
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if(size) *size = oldlen;
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return 0;
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}
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int ASN1CALL
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der_get_unsigned64 (const unsigned char *p, size_t len,
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uint64_t *ret, size_t *size)
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{
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uint64_t val = 0;
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size_t oldlen = len;
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if (len == sizeof(val) + 1 && p[0] == 0)
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;
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else if (len > sizeof(val))
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return ASN1_OVERRUN;
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while (len--)
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val = val * 256 + *p++;
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*ret = val;
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if(size) *size = oldlen;
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return 0;
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}
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int ASN1CALL
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der_get_integer (const unsigned char *p, size_t len,
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int *ret, size_t *size)
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{
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int val = 0;
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size_t oldlen = len;
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if (len > sizeof(val))
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return ASN1_OVERRUN;
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if (len > 0) {
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val = (signed char)*p++;
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while (--len)
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val = val * 256 + *p++;
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}
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*ret = val;
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if(size) *size = oldlen;
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return 0;
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}
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int ASN1CALL
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der_get_integer64 (const unsigned char *p, size_t len,
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int64_t *ret, size_t *size)
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{
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int64_t val = 0;
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size_t oldlen = len;
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if (len > sizeof(val))
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return ASN1_OVERRUN;
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if (len > 0) {
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val = (signed char)*p++;
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while (--len)
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val = val * 256 + *p++;
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}
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*ret = val;
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if(size) *size = oldlen;
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return 0;
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}
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int ASN1CALL
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der_get_length (const unsigned char *p, size_t len,
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size_t *val, size_t *size)
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{
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size_t v;
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if (len <= 0)
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return ASN1_OVERRUN;
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--len;
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v = *p++;
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if (v < 128) {
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*val = v;
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if(size) *size = 1;
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} else {
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int e;
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size_t l;
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unsigned tmp;
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if(v == 0x80){
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*val = ASN1_INDEFINITE;
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if(size) *size = 1;
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return 0;
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}
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v &= 0x7F;
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if (len < v)
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return ASN1_OVERRUN;
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e = der_get_unsigned (p, v, &tmp, &l);
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if(e) return e;
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*val = tmp;
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if(size) *size = l + 1;
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}
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return 0;
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}
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int ASN1CALL
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der_get_boolean(const unsigned char *p, size_t len, int *data, size_t *size)
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{
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if(len < 1)
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return ASN1_OVERRUN;
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if(*p != 0)
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*data = 1;
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else
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*data = 0;
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*size = 1;
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return 0;
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}
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int ASN1CALL
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der_get_general_string (const unsigned char *p, size_t len,
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heim_general_string *str, size_t *size)
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{
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const unsigned char *p1;
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char *s;
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p1 = memchr(p, 0, len);
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if (p1 != NULL) {
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/*
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* Allow trailing NULs. We allow this since MIT Kerberos sends
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* an strings in the NEED_PREAUTH case that includes a
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* trailing NUL.
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*/
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while ((size_t)(p1 - p) < len && *p1 == '\0')
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p1++;
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if ((size_t)(p1 - p) != len) {
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*str = NULL;
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return ASN1_BAD_CHARACTER;
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}
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}
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if (len == SIZE_MAX) {
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*str = NULL;
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return ASN1_BAD_LENGTH;
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}
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*str = s = malloc (len + 1);
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if (s == NULL)
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return ENOMEM;
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memcpy (s, p, len);
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s[len] = '\0';
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if(size) *size = len;
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return 0;
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}
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int ASN1CALL
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der_get_utf8string (const unsigned char *p, size_t len,
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heim_utf8_string *str, size_t *size)
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{
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return der_get_general_string(p, len, str, size);
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}
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#define gen_data_zero(_data) \
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do { (_data)->length = 0; (_data)->data = NULL; } while(0)
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int ASN1CALL
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der_get_printable_string(const unsigned char *p, size_t len,
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heim_printable_string *str, size_t *size)
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{
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if (len == SIZE_MAX) {
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gen_data_zero(str);
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return ASN1_BAD_LENGTH;
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}
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str->length = len;
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str->data = malloc(len + 1);
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if (str->data == NULL) {
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gen_data_zero(str);
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return ENOMEM;
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}
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memcpy(str->data, p, len);
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((char *)str->data)[len] = '\0';
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if(size) *size = len;
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return 0;
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}
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int ASN1CALL
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der_get_ia5_string(const unsigned char *p, size_t len,
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heim_ia5_string *str, size_t *size)
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{
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return der_get_printable_string(p, len, str, size);
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}
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int ASN1CALL
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der_get_bmp_string (const unsigned char *p, size_t len,
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heim_bmp_string *data, size_t *size)
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{
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size_t i;
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if (len & 1) {
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gen_data_zero(data);
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return ASN1_BAD_FORMAT;
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}
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data->length = len / 2;
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if (data->length > UINT_MAX/sizeof(data->data[0])) {
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gen_data_zero(data);
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return ERANGE;
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}
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data->data = malloc(data->length * sizeof(data->data[0]));
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if (data->data == NULL && data->length != 0) {
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gen_data_zero(data);
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return ENOMEM;
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}
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for (i = 0; i < data->length; i++) {
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data->data[i] = (p[0] << 8) | p[1];
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p += 2;
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/* check for NUL in the middle of the string */
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if (data->data[i] == 0 && i != (data->length - 1)) {
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free(data->data);
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gen_data_zero(data);
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return ASN1_BAD_CHARACTER;
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}
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}
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if (size) *size = len;
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return 0;
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}
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int ASN1CALL
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der_get_universal_string (const unsigned char *p, size_t len,
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heim_universal_string *data, size_t *size)
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{
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size_t i;
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if (len & 3) {
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gen_data_zero(data);
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return ASN1_BAD_FORMAT;
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}
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data->length = len / 4;
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if (data->length > UINT_MAX/sizeof(data->data[0])) {
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gen_data_zero(data);
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return ERANGE;
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}
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data->data = malloc(data->length * sizeof(data->data[0]));
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if (data->data == NULL && data->length != 0) {
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gen_data_zero(data);
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return ENOMEM;
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}
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for (i = 0; i < data->length; i++) {
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data->data[i] = (p[0] << 24) | (p[1] << 16) | (p[2] << 8) | p[3];
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p += 4;
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/* check for NUL in the middle of the string */
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if (data->data[i] == 0 && i != (data->length - 1)) {
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free(data->data);
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gen_data_zero(data);
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return ASN1_BAD_CHARACTER;
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}
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}
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if (size) *size = len;
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return 0;
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}
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int ASN1CALL
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der_get_visible_string (const unsigned char *p, size_t len,
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heim_visible_string *str, size_t *size)
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{
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return der_get_general_string(p, len, str, size);
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}
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int ASN1CALL
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der_get_octet_string (const unsigned char *p, size_t len,
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heim_octet_string *data, size_t *size)
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{
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data->length = len;
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data->data = malloc(len);
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if (data->data == NULL && data->length != 0)
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return ENOMEM;
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memcpy (data->data, p, len);
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if(size) *size = len;
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return 0;
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}
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int ASN1CALL
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der_get_octet_string_ber (const unsigned char *p, size_t len,
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heim_octet_string *data, size_t *size)
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{
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int e;
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Der_type type;
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Der_class cls;
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unsigned int tag, depth = 0;
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size_t l, datalen, oldlen = len;
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data->length = 0;
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data->data = NULL;
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while (len) {
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e = der_get_tag (p, len, &cls, &type, &tag, &l);
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if (e) goto out;
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if (cls != ASN1_C_UNIV) {
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e = ASN1_BAD_ID;
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goto out;
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}
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if (type == PRIM && tag == UT_EndOfContent) {
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if (depth == 0)
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break;
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depth--;
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}
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if (tag != UT_OctetString) {
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e = ASN1_BAD_ID;
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goto out;
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}
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p += l;
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len -= l;
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e = der_get_length (p, len, &datalen, &l);
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if (e) goto out;
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p += l;
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len -= l;
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if (datalen > len)
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return ASN1_OVERRUN;
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if (type == PRIM && datalen) {
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void *ptr;
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ptr = realloc(data->data, data->length + datalen);
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if (ptr == NULL) {
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e = ENOMEM;
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goto out;
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}
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data->data = ptr;
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memcpy(((unsigned char *)data->data) + data->length, p, datalen);
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data->length += datalen;
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} else if (type != PRIM)
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depth++;
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p += datalen;
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len -= datalen;
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}
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if (depth != 0)
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return ASN1_INDEF_OVERRUN;
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if(size) *size = oldlen - len;
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return 0;
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out:
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free(data->data);
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data->data = NULL;
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data->length = 0;
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return e;
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}
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int ASN1CALL
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der_get_heim_integer (const unsigned char *p, size_t len,
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heim_integer *data, size_t *size)
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{
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data->length = 0;
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data->negative = 0;
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data->data = NULL;
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if (len == 0) {
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if (size)
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*size = 0;
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return 0;
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}
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if (p[0] & 0x80) {
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unsigned char *q;
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int carry = 1;
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data->negative = 1;
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data->length = len;
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if (p[0] == 0xff) {
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p++;
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data->length--;
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}
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data->data = malloc(data->length);
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if (data->data == NULL) {
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data->length = 0;
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if (size)
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*size = 0;
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return ENOMEM;
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}
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q = &((unsigned char*)data->data)[data->length - 1];
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p += data->length - 1;
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while (q >= (unsigned char*)data->data) {
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*q = *p ^ 0xff;
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if (carry)
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carry = !++*q;
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p--;
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q--;
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}
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} else {
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data->negative = 0;
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data->length = len;
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if (p[0] == 0) {
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p++;
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data->length--;
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}
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data->data = malloc(data->length);
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if (data->data == NULL && data->length != 0) {
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data->length = 0;
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if (size)
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*size = 0;
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return ENOMEM;
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}
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memcpy(data->data, p, data->length);
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}
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if (size)
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*size = len;
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return 0;
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}
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static int
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generalizedtime2time (const char *s, time_t *t)
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{
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struct tm tm;
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memset(&tm, 0, sizeof(tm));
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if (sscanf (s, "%04d%02d%02d%02d%02d%02dZ",
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&tm.tm_year, &tm.tm_mon, &tm.tm_mday, &tm.tm_hour,
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&tm.tm_min, &tm.tm_sec) != 6) {
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if (sscanf (s, "%02d%02d%02d%02d%02d%02dZ",
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&tm.tm_year, &tm.tm_mon, &tm.tm_mday, &tm.tm_hour,
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&tm.tm_min, &tm.tm_sec) != 6)
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return ASN1_BAD_TIMEFORMAT;
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if (tm.tm_year < 50)
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tm.tm_year += 2000;
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else
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tm.tm_year += 1900;
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}
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tm.tm_year -= 1900;
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tm.tm_mon -= 1;
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*t = _der_timegm (&tm);
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return 0;
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}
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static int ASN1CALL
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der_get_time (const unsigned char *p, size_t len,
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time_t *data, size_t *size)
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{
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char *times;
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int e;
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if (len == SIZE_MAX || len == 0)
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return ASN1_BAD_LENGTH;
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times = malloc(len + 1);
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if (times == NULL)
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return ENOMEM;
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memcpy(times, p, len);
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times[len] = '\0';
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e = generalizedtime2time(times, data);
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free (times);
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if(size) *size = len;
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return e;
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}
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int ASN1CALL
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der_get_generalized_time (const unsigned char *p, size_t len,
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time_t *data, size_t *size)
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{
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return der_get_time(p, len, data, size);
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}
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int ASN1CALL
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der_get_utctime (const unsigned char *p, size_t len,
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time_t *data, size_t *size)
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{
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return der_get_time(p, len, data, size);
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}
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int ASN1CALL
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der_get_oid (const unsigned char *p, size_t len,
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heim_oid *data, size_t *size)
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{
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size_t n;
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size_t oldlen = len;
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if (len < 1)
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return ASN1_OVERRUN;
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if (len == SIZE_MAX)
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return ASN1_BAD_LENGTH;
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if (len + 1 > UINT_MAX/sizeof(data->components[0]))
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return ERANGE;
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data->components = malloc((len + 1) * sizeof(data->components[0]));
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if (data->components == NULL)
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return ENOMEM;
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data->components[0] = (*p) / 40;
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data->components[1] = (*p) % 40;
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--len;
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++p;
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for (n = 2; len > 0; ++n) {
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unsigned u = 0, u1;
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do {
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--len;
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u1 = u * 128 + (*p++ % 128);
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/* check that we don't overflow the element */
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if (u1 < u) {
|
|
der_free_oid(data);
|
|
return ASN1_OVERRUN;
|
|
}
|
|
u = u1;
|
|
} while (len > 0 && p[-1] & 0x80);
|
|
data->components[n] = u;
|
|
}
|
|
if (n > 2 && p[-1] & 0x80) {
|
|
der_free_oid (data);
|
|
return ASN1_OVERRUN;
|
|
}
|
|
data->length = n;
|
|
if (size)
|
|
*size = oldlen;
|
|
return 0;
|
|
}
|
|
|
|
int ASN1CALL
|
|
der_get_tag (const unsigned char *p, size_t len,
|
|
Der_class *cls, Der_type *type,
|
|
unsigned int *tag, size_t *size)
|
|
{
|
|
size_t ret = 0;
|
|
if (len < 1)
|
|
return ASN1_MISSING_FIELD;
|
|
*cls = (Der_class)(((*p) >> 6) & 0x03);
|
|
*type = (Der_type)(((*p) >> 5) & 0x01);
|
|
*tag = (*p) & 0x1f;
|
|
p++; len--; ret++;
|
|
if(*tag == 0x1f) {
|
|
unsigned int continuation;
|
|
unsigned int tag1;
|
|
*tag = 0;
|
|
do {
|
|
if(len < 1)
|
|
return ASN1_OVERRUN;
|
|
continuation = *p & 128;
|
|
tag1 = *tag * 128 + (*p % 128);
|
|
/* check that we don't overflow the tag */
|
|
if (tag1 < *tag)
|
|
return ASN1_OVERFLOW;
|
|
*tag = tag1;
|
|
p++; len--; ret++;
|
|
} while(continuation);
|
|
}
|
|
if(size) *size = ret;
|
|
return 0;
|
|
}
|
|
|
|
int ASN1CALL
|
|
der_match_tag (const unsigned char *p, size_t len,
|
|
Der_class cls, Der_type type,
|
|
unsigned int tag, size_t *size)
|
|
{
|
|
Der_type thistype;
|
|
int e;
|
|
|
|
e = der_match_tag2(p, len, cls, &thistype, tag, size);
|
|
if (e) return e;
|
|
if (thistype != type) return ASN1_BAD_ID;
|
|
return 0;
|
|
}
|
|
|
|
int ASN1CALL
|
|
der_match_tag2 (const unsigned char *p, size_t len,
|
|
Der_class cls, Der_type *type,
|
|
unsigned int tag, size_t *size)
|
|
{
|
|
size_t l;
|
|
Der_class thisclass;
|
|
unsigned int thistag;
|
|
int e;
|
|
|
|
e = der_get_tag(p, len, &thisclass, type, &thistag, &l);
|
|
if (e) return e;
|
|
/*
|
|
* We do depend on ASN1_BAD_ID being returned in places where we're
|
|
* essentially implementing an application-level CHOICE where we try to
|
|
* decode one way then the other. In Heimdal this happens only in lib/hdb/
|
|
* where we try to decode a blob as an hdb_entry, then as an
|
|
* hdb_entry_alias. Applications should really not depend on this.
|
|
*/
|
|
if (cls != thisclass && (cls == ASN1_C_APPL || thisclass == ASN1_C_APPL))
|
|
return ASN1_BAD_ID;
|
|
if (cls != thisclass || tag != thistag)
|
|
return ASN1_MISSING_FIELD;
|
|
if (size) *size = l;
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* Returns 0 if the encoded data at `p' of length `len' starts with the tag of
|
|
* class `cls`, type `type', and tag value `tag', and puts the length of the
|
|
* payload (i.e., the length of V in TLV, not the length of TLV) in
|
|
* `*length_ret', and the size of the whole thing (the TLV) in `*size' if
|
|
* `size' is not NULL.
|
|
*
|
|
* Else returns an error.
|
|
*/
|
|
int ASN1CALL
|
|
der_match_tag_and_length (const unsigned char *p, size_t len,
|
|
Der_class cls, Der_type *type, unsigned int tag,
|
|
size_t *length_ret, size_t *size)
|
|
{
|
|
size_t l, ret = 0;
|
|
int e;
|
|
|
|
e = der_match_tag2 (p, len, cls, type, tag, &l);
|
|
if (e) return e;
|
|
p += l;
|
|
len -= l;
|
|
ret += l;
|
|
e = der_get_length (p, len, length_ret, &l);
|
|
if (e) return e;
|
|
if(size) *size = ret + l;
|
|
return 0;
|
|
}
|
|
|
|
|
|
|
|
/*
|
|
* Old versions of DCE was based on a very early beta of the MIT code,
|
|
* which used MAVROS for ASN.1 encoding. MAVROS had the interesting
|
|
* feature that it encoded data in the forward direction, which has
|
|
* it's problems, since you have no idea how long the data will be
|
|
* until after you're done. MAVROS solved this by reserving one byte
|
|
* for length, and later, if the actual length was longer, it reverted
|
|
* to indefinite, BER style, lengths. The version of MAVROS used by
|
|
* the DCE people could apparently generate correct X.509 DER encodings, and
|
|
* did this by making space for the length after encoding, but
|
|
* unfortunately this feature wasn't used with Kerberos.
|
|
*/
|
|
|
|
int
|
|
_heim_fix_dce(size_t reallen, size_t *len)
|
|
{
|
|
if(reallen == ASN1_INDEFINITE)
|
|
return 1;
|
|
if(*len < reallen)
|
|
return -1;
|
|
*len = reallen;
|
|
return 0;
|
|
}
|
|
|
|
int ASN1CALL
|
|
der_get_bit_string (const unsigned char *p, size_t len,
|
|
heim_bit_string *data, size_t *size)
|
|
{
|
|
if (len < 1)
|
|
return ASN1_OVERRUN;
|
|
if (p[0] > 7)
|
|
return ASN1_BAD_FORMAT;
|
|
if (len - 1 == 0 && p[0] != 0)
|
|
return ASN1_BAD_FORMAT;
|
|
/* check if any of the three upper bits are set
|
|
* any of them will cause a interger overrun */
|
|
if ((len - 1) >> (sizeof(len) * 8 - 3))
|
|
return ASN1_OVERRUN;
|
|
/*
|
|
* If there is data to copy, do that now.
|
|
*/
|
|
if (len - 1 > 0) {
|
|
data->length = (len - 1) * 8;
|
|
data->data = malloc(len - 1);
|
|
if (data->data == NULL)
|
|
return ENOMEM;
|
|
memcpy (data->data, p + 1, len - 1);
|
|
data->length -= p[0];
|
|
} else {
|
|
data->data = NULL;
|
|
data->length = 0;
|
|
}
|
|
if(size) *size = len;
|
|
return 0;
|
|
}
|