/* $OpenBSD: ber.c,v 1.9 2015/02/12 00:30:38 pelikan Exp $ */
/*
* Copyright (c) 2007 Reyk Floeter <reyk@vantronix.net>
* Copyright (c) 2006, 2007 Claudio Jeker <claudio@openbsd.org>
* Copyright (c) 2006, 2007 Marc Balmer <mbalmer@openbsd.org>
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
*
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
* ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
* ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
#include <sys/types.h>
#include <errno.h>
#include <limits.h>
#include <stdlib.h>
#include <err.h> /* XXX for debug output */
#include <stdio.h> /* XXX for debug output */
#include <string.h>
#include <unistd.h>
#include <stdarg.h>
#include "ber.h"
#define MINIMUM(a, b) (((a) < (b)) ? (a) : (b))
#define BER_TYPE_CONSTRUCTED 0x20 /* otherwise primitive */
#define BER_TYPE_SINGLE_MAX 30
#define BER_TAG_MASK 0x1f
#define BER_TAG_MORE 0x80 /* more subsequent octets */
#define BER_TAG_TYPE_MASK 0x7f
#define BER_CLASS_SHIFT 6
static int ber_dump_element(struct ber *ber, struct ber_element *root);
static void ber_dump_header(struct ber *ber, struct ber_element *root);
static void ber_putc(struct ber *ber, u_char c);
static void ber_write(struct ber *ber, void *buf, size_t len);
static ssize_t get_id(struct ber *b, unsigned long *tag, int *class,
int *cstruct);
static ssize_t get_len(struct ber *b, ssize_t *len);
static ssize_t ber_read_element(struct ber *ber, struct ber_element *elm);
static ssize_t ber_readbuf(struct ber *b, void *buf, size_t nbytes);
static ssize_t ber_getc(struct ber *b, u_char *c);
static ssize_t ber_read(struct ber *ber, void *buf, size_t len);
#ifdef DEBUG
#define DPRINTF(...) printf(__VA_ARGS__)
#else
#define DPRINTF(...) do { } while (0)
#endif
struct ber_element *
ber_get_element(unsigned long encoding)
{
struct ber_element *elm;
if ((elm = calloc(1, sizeof(*elm))) == NULL)
return NULL;
elm->be_encoding = encoding;
ber_set_header(elm, BER_CLASS_UNIVERSAL, BER_TYPE_DEFAULT);
return elm;
}
void
ber_set_header(struct ber_element *elm, int class, unsigned long type)
{
elm->be_class = class & BER_CLASS_MASK;
if (type == BER_TYPE_DEFAULT)
type = elm->be_encoding;
elm->be_type = type;
}
void
ber_link_elements(struct ber_element *prev, struct ber_element *elm)
{
if (prev != NULL) {
if ((prev->be_encoding == BER_TYPE_SEQUENCE ||
prev->be_encoding == BER_TYPE_SET) &&
prev->be_sub == NULL)
prev->be_sub = elm;
else
prev->be_next = elm;
}
}
struct ber_element *
ber_unlink_elements(struct ber_element *prev)
{
struct ber_element *elm;
if ((prev->be_encoding == BER_TYPE_SEQUENCE ||
prev->be_encoding == BER_TYPE_SET) &&
prev->be_sub != NULL) {
elm = prev->be_sub;
prev->be_sub = NULL;
} else {
elm = prev->be_next;
prev->be_next = NULL;
}
return (elm);
}
void
ber_replace_elements(struct ber_element *prev, struct ber_element *new)
{
struct ber_element *ber, *next;
ber = ber_unlink_elements(prev);
next = ber_unlink_elements(ber);
ber_link_elements(new, next);
ber_link_elements(prev, new);
/* cleanup old element */
ber_free_elements(ber);
}
struct ber_element *
ber_add_sequence(struct ber_element *prev)
{
struct ber_element *elm;
if ((elm = ber_get_element(BER_TYPE_SEQUENCE)) == NULL)
return NULL;
ber_link_elements(prev, elm);
return elm;
}
struct ber_element *
ber_add_set(struct ber_element *prev)
{
struct ber_element *elm;
if ((elm = ber_get_element(BER_TYPE_SET)) == NULL)
return NULL;
ber_link_elements(prev, elm);
return elm;
}
struct ber_element *
ber_add_enumerated(struct ber_element *prev, long long val)
{
struct ber_element *elm;
u_int i, len = 0;
u_char cur, last = 0;
if ((elm = ber_get_element(BER_TYPE_ENUMERATED)) == NULL)
return NULL;
elm->be_numeric = val;
for (i = 0; i < sizeof(long long); i++) {
cur = val & 0xff;
if (cur != 0 && cur != 0xff)
len = i;
if ((cur == 0 && last & 0x80) ||
(cur == 0xff && (last & 0x80) == 0))
len = i;
val >>= 8;
last = cur;
}
elm->be_len = len + 1;
ber_link_elements(prev, elm);
return elm;
}
struct ber_element *
ber_add_integer(struct ber_element *prev, long long val)
{
struct ber_element *elm;
u_int i, len = 0;
u_char cur, last = 0;
if ((elm = ber_get_element(BER_TYPE_INTEGER)) == NULL)
return NULL;
elm->be_numeric = val;
for (i = 0; i < sizeof(long long); i++) {
cur = val & 0xff;
if (cur != 0 && cur != 0xff)
len = i;
if ((cur == 0 && last & 0x80) ||
(cur == 0xff && (last & 0x80) == 0))
len = i;
val >>= 8;
last = cur;
}
elm->be_len = len + 1;
ber_link_elements(prev, elm);
return elm;
}
int
ber_get_integer(struct ber_element *elm, long long *n)
{
if (elm->be_encoding != BER_TYPE_INTEGER)
return -1;
*n = elm->be_numeric;
return 0;
}
int
ber_get_enumerated(struct ber_element *elm, long long *n)
{
if (elm->be_encoding != BER_TYPE_ENUMERATED)
return -1;
*n = elm->be_numeric;
return 0;
}
struct ber_element *
ber_add_boolean(struct ber_element *prev, int bool)
{
struct ber_element *elm;
if ((elm = ber_get_element(BER_TYPE_BOOLEAN)) == NULL)
return NULL;
elm->be_numeric = bool ? 0xff : 0;
elm->be_len = 1;
ber_link_elements(prev, elm);
return elm;
}
int
ber_get_boolean(struct ber_element *elm, int *b)
{
if (elm->be_encoding != BER_TYPE_BOOLEAN)
return -1;
*b = !(elm->be_numeric == 0);
return 0;
}
struct ber_element *
ber_add_string(struct ber_element *prev, const char *string)
{
return ber_add_nstring(prev, string, strlen(string));
}
struct ber_element *
ber_add_nstring(struct ber_element *prev, const char *string0, size_t len)
{
struct ber_element *elm;
char *string;
if ((string = calloc(1, len)) == NULL)
return NULL;
if ((elm = ber_get_element(BER_TYPE_OCTETSTRING)) == NULL) {
free(string);
return NULL;
}
bcopy(string0, string, len);
elm->be_val = string;
elm->be_len = len;
elm->be_free = 1; /* free string on cleanup */
ber_link_elements(prev, elm);
return elm;
}
int
ber_get_string(struct ber_element *elm, char **s)
{
if (elm->be_encoding != BER_TYPE_OCTETSTRING)
return -1;
*s = elm->be_val;
return 0;
}
int
ber_get_nstring(struct ber_element *elm, void **p, size_t *len)
{
if (elm->be_encoding != BER_TYPE_OCTETSTRING)
return -1;
*p = elm->be_val;
*len = elm->be_len;
return 0;
}
struct ber_element *
ber_add_bitstring(struct ber_element *prev, const void *v0, size_t len)
{
struct ber_element *elm;
void *v;
if ((v = calloc(1, len)) == NULL)
return NULL;
if ((elm = ber_get_element(BER_TYPE_BITSTRING)) == NULL) {
free(v);
return NULL;
}
bcopy(v0, v, len);
elm->be_val = v;
elm->be_len = len;
elm->be_free = 1; /* free string on cleanup */
ber_link_elements(prev, elm);
return elm;
}
int
ber_get_bitstring(struct ber_element *elm, void **v, size_t *len)
{
if (elm->be_encoding != BER_TYPE_BITSTRING)
return -1;
*v = elm->be_val;
*len = elm->be_len;
return 0;
}
struct ber_element *
ber_add_null(struct ber_element *prev)
{
struct ber_element *elm;
if ((elm = ber_get_element(BER_TYPE_NULL)) == NULL)
return NULL;
ber_link_elements(prev, elm);
return elm;
}
int
ber_get_null(struct ber_element *elm)
{
if (elm->be_encoding != BER_TYPE_NULL)
return -1;
return 0;
}
struct ber_element *
ber_add_eoc(struct ber_element *prev)
{
struct ber_element *elm;
if ((elm = ber_get_element(BER_TYPE_EOC)) == NULL)
return NULL;
ber_link_elements(prev, elm);
return elm;
}
int
ber_get_eoc(struct ber_element *elm)
{
if (elm->be_encoding != BER_TYPE_EOC)
return -1;
return 0;
}
size_t
ber_oid2ber(struct ber_oid *o, u_int8_t *buf, size_t len)
{
u_int32_t v;
u_int i, j = 0, k;
if (o->bo_n < BER_MIN_OID_LEN || o->bo_n > BER_MAX_OID_LEN ||
o->bo_id[0] > 2 || o->bo_id[1] > 40)
return (0);
v = (o->bo_id[0] * 40) + o->bo_id[1];
for (i = 2, j = 0; i <= o->bo_n; v = o->bo_id[i], i++) {
for (k = 28; k >= 7; k -= 7) {
if (v >= (u_int)(1 << k)) {
if (len)
buf[j] = v >> k | BER_TAG_MORE;
j++;
}
}
if (len)
buf[j] = v & BER_TAG_TYPE_MASK;
j++;
}
return (j);
}
int
ber_string2oid(const char *oidstr, struct ber_oid *o)
{
char *sp, *p, str[BUFSIZ];
const char *errstr;
if (strlcpy(str, oidstr, sizeof(str)) >= sizeof(str))
return (-1);
bzero(o, sizeof(*o));
/* Parse OID strings in the common forms n.n.n, n_n_n_n, or n-n-n */
for (p = sp = str; p != NULL; sp = p) {
if ((p = strpbrk(p, "._-")) != NULL)
*p++ = '\0';
o->bo_id[o->bo_n++] = strtonum(sp, 0, UINT_MAX, &errstr);
if (errstr || o->bo_n > BER_MAX_OID_LEN)
return (-1);
}
return (0);
}
struct ber_element *
ber_add_oid(struct ber_element *prev, struct ber_oid *o)
{
struct ber_element *elm;
u_int8_t *buf;
size_t len;
if ((elm = ber_get_element(BER_TYPE_OBJECT)) == NULL)
return (NULL);
if ((len = ber_oid2ber(o, NULL, 0)) == 0)
goto fail;
if ((buf = calloc(1, len)) == NULL)
goto fail;
elm->be_val = buf;
elm->be_len = len;
elm->be_free = 1;
if (ber_oid2ber(o, buf, len) != len)
goto fail;
ber_link_elements(prev, elm);
return (elm);
fail:
ber_free_elements(elm);
return (NULL);
}
struct ber_element *
ber_add_noid(struct ber_element *prev, struct ber_oid *o, int n)
{
struct ber_oid no;
if (n > BER_MAX_OID_LEN)
return (NULL);
no.bo_n = n;
bcopy(&o->bo_id, &no.bo_id, sizeof(no.bo_id));
return (ber_add_oid(prev, &no));
}
struct ber_element *
ber_add_oidstring(struct ber_element *prev, const char *oidstr)
{
struct ber_oid o;
if (ber_string2oid(oidstr, &o) == -1)
return (NULL);
return (ber_add_oid(prev, &o));
}
int
ber_get_oid(struct ber_element *elm, struct ber_oid *o)
{
u_int8_t *buf;
size_t len, i = 0, j = 0;
if (elm->be_encoding != BER_TYPE_OBJECT)
return (-1);
buf = elm->be_val;
len = elm->be_len;
if (!buf[i])
return (-1);
bzero(o, sizeof(*o));
o->bo_id[j++] = buf[i] / 40;
o->bo_id[j++] = buf[i++] % 40;
for (; i < len && j < BER_MAX_OID_LEN; i++) {
o->bo_id[j] = (o->bo_id[j] << 7) + (buf[i] & ~0x80);
if (buf[i] & 0x80)
continue;
j++;
}
o->bo_n = j;
return (0);
}
struct ber_element *
ber_printf_elements(struct ber_element *ber, char *fmt, ...)
{
va_list ap;
int d, class;
size_t len;
unsigned long type;
long long i;
char *s;
void *p;
struct ber_oid *o;
struct ber_element *sub = ber, *e;
va_start(ap, fmt);
while (*fmt) {
switch (*fmt++) {
case 'B':
p = va_arg(ap, void *);
len = va_arg(ap, size_t);
if ((ber = ber_add_bitstring(ber, p, len)) == NULL)
goto fail;
break;
case 'b':
d = va_arg(ap, int);
if ((ber = ber_add_boolean(ber, d)) == NULL)
goto fail;
break;
case 'd':
d = va_arg(ap, int);
if ((ber = ber_add_integer(ber, d)) == NULL)
goto fail;
break;
case 'e':
e = va_arg(ap, struct ber_element *);
ber_link_elements(ber, e);
break;
case 'E':
i = va_arg(ap, long long);
if ((ber = ber_add_enumerated(ber, i)) == NULL)
goto fail;
break;
case 'i':
i = va_arg(ap, long long);
if ((ber = ber_add_integer(ber, i)) == NULL)
goto fail;
break;
case 'O':
o = va_arg(ap, struct ber_oid *);
if ((ber = ber_add_oid(ber, o)) == NULL)
goto fail;
break;
case 'o':
s = va_arg(ap, char *);
if ((ber = ber_add_oidstring(ber, s)) == NULL)
goto fail;
break;
case 's':
s = va_arg(ap, char *);
if ((ber = ber_add_string(ber, s)) == NULL)
goto fail;
break;
case 't':
class = va_arg(ap, int);
type = va_arg(ap, unsigned long);
ber_set_header(ber, class, type);
break;
case 'x':
s = va_arg(ap, char *);
len = va_arg(ap, size_t);
if ((ber = ber_add_nstring(ber, s, len)) == NULL)
goto fail;
break;
case '0':
if ((ber = ber_add_null(ber)) == NULL)
goto fail;
break;
case '{':
if ((ber = sub = ber_add_sequence(ber)) == NULL)
goto fail;
break;
case '(':
if ((ber = sub = ber_add_set(ber)) == NULL)
goto fail;
break;
case '}':
case ')':
ber = sub;
break;
case '.':
if ((e = ber_add_eoc(ber)) == NULL)
goto fail;
ber = e;
break;
default:
break;
}
}
va_end(ap);
return (ber);
fail:
va_end(ap);
return (NULL);
}
int
ber_scanf_elements(struct ber_element *ber, char *fmt, ...)
{
#define _MAX_SEQ 128
va_list ap;
int *d, level = -1;
unsigned long *t;
long long *i;
void **ptr;
size_t *len, ret = 0, n = strlen(fmt);
char **s;
struct ber_oid *o;
struct ber_element *parent[_MAX_SEQ], **e;
bzero(parent, sizeof(struct ber_element *) * _MAX_SEQ);
va_start(ap, fmt);
while (*fmt) {
switch (*fmt++) {
case 'B':
ptr = va_arg(ap, void **);
len = va_arg(ap, size_t *);
if (ber_get_bitstring(ber, ptr, len) == -1)
goto fail;
ret++;
break;
case 'b':
d = va_arg(ap, int *);
if (ber_get_boolean(ber, d) == -1)
goto fail;
ret++;
break;
case 'e':
e = va_arg(ap, struct ber_element **);
*e = ber;
ret++;
continue;
case 'E':
i = va_arg(ap, long long *);
if (ber_get_enumerated(ber, i) == -1)
goto fail;
ret++;
break;
case 'i':
i = va_arg(ap, long long *);
if (ber_get_integer(ber, i) == -1)
goto fail;
ret++;
break;
case 'o':
o = va_arg(ap, struct ber_oid *);
if (ber_get_oid(ber, o) == -1)
goto fail;
ret++;
break;
case 'S':
ret++;
break;
case 's':
s = va_arg(ap, char **);
if (ber_get_string(ber, s) == -1)
goto fail;
ret++;
break;
case 't':
d = va_arg(ap, int *);
t = va_arg(ap, unsigned long *);
*d = ber->be_class;
*t = ber->be_type;
ret++;
continue;
case 'x':
ptr = va_arg(ap, void **);
len = va_arg(ap, size_t *);
if (ber_get_nstring(ber, ptr, len) == -1)
goto fail;
ret++;
break;
case '0':
if (ber->be_encoding != BER_TYPE_NULL)
goto fail;
ret++;
break;
case '.':
if (ber->be_encoding != BER_TYPE_EOC)
goto fail;
ret++;
break;
case '{':
case '(':
if (ber->be_encoding != BER_TYPE_SEQUENCE &&
ber->be_encoding != BER_TYPE_SET)
goto fail;
if (ber->be_sub == NULL || level >= _MAX_SEQ-1)
goto fail;
parent[++level] = ber;
ber = ber->be_sub;
ret++;
continue;
case '}':
case ')':
if (level < 0 || parent[level] == NULL)
goto fail;
ber = parent[level--];
ret++;
continue;
default:
goto fail;
}
if (ber->be_next == NULL)
continue;
ber = ber->be_next;
}
va_end(ap);
return (ret == n ? 0 : -1);
fail:
va_end(ap);
return (-1);
}
/*
* write ber elements to the socket
*
* params:
* ber holds the socket
* root fully populated element tree
*
* returns:
* >=0 number of bytes written
* -1 on failure and sets errno
*/
int
ber_write_elements(struct ber *ber, struct ber_element *root)
{
size_t len;
/* calculate length because only the definite form is required */
len = ber_calc_len(root);
DPRINTF("write ber element of %zd bytes length\n", len);
if (ber->br_wbuf != NULL && ber->br_wbuf + len > ber->br_wend) {
free(ber->br_wbuf);
ber->br_wbuf = NULL;
}
if (ber->br_wbuf == NULL) {
if ((ber->br_wbuf = malloc(len)) == NULL)
return -1;
ber->br_wend = ber->br_wbuf + len;
}
/* reset write pointer */
ber->br_wptr = ber->br_wbuf;
if (ber_dump_element(ber, root) == -1)
return -1;
/* XXX this should be moved to a different function */
if (ber->fd != -1)
return write(ber->fd, ber->br_wbuf, len);
return (len);
}
/*
* read ber elements from the socket
*
* params:
* ber holds the socket and lot more
* root if NULL, build up an element tree from what we receive on
* the wire. If not null, use the specified encoding for the
* elements received.
*
* returns:
* !=NULL, elements read and store in the ber_element tree
* NULL, type mismatch or read error
*/
struct ber_element *
ber_read_elements(struct ber *ber, struct ber_element *elm)
{
struct ber_element *root = elm;
if (root == NULL) {
if ((root = ber_get_element(0)) == NULL)
return NULL;
}
DPRINTF("read ber elements, root %p\n", root);
if (ber_read_element(ber, root) == -1) {
/* Cleanup if root was allocated by us */
if (elm == NULL)
ber_free_elements(root);
return NULL;
}
return root;
}
void
ber_free_elements(struct ber_element *root)
{
if (root->be_sub && (root->be_encoding == BER_TYPE_SEQUENCE ||
root->be_encoding == BER_TYPE_SET))
ber_free_elements(root->be_sub);
if (root->be_next)
ber_free_elements(root->be_next);
if (root->be_free && (root->be_encoding == BER_TYPE_OCTETSTRING ||
root->be_encoding == BER_TYPE_BITSTRING ||
root->be_encoding == BER_TYPE_OBJECT))
free(root->be_val);
free(root);
}
size_t
ber_calc_len(struct ber_element *root)
{
unsigned long t;
size_t s;
size_t size = 2; /* minimum 1 byte head and 1 byte size */
/* calculate the real length of a sequence or set */
if (root->be_sub && (root->be_encoding == BER_TYPE_SEQUENCE ||
root->be_encoding == BER_TYPE_SET))
root->be_len = ber_calc_len(root->be_sub);
/* fix header length for extended types */
if (root->be_type > BER_TYPE_SINGLE_MAX)
for (t = root->be_type; t > 0; t >>= 7)
size++;
if (root->be_len >= BER_TAG_MORE)
for (s = root->be_len; s > 0; s >>= 8)
size++;
/* calculate the length of the following elements */
if (root->be_next)
size += ber_calc_len(root->be_next);
/* This is an empty element, do not use a minimal size */
if (root->be_type == BER_TYPE_EOC && root->be_len == 0)
return (0);
return (root->be_len + size);
}
/*
* internal functions
*/
static int
ber_dump_element(struct ber *ber, struct ber_element *root)
{
unsigned long long l;
int i;
uint8_t u;
ber_dump_header(ber, root);
switch (root->be_encoding) {
case BER_TYPE_BOOLEAN:
case BER_TYPE_INTEGER:
case BER_TYPE_ENUMERATED:
l = (unsigned long long)root->be_numeric;
for (i = root->be_len; i > 0; i--) {
u = (l >> ((i - 1) * 8)) & 0xff;
ber_putc(ber, u);
}
break;
case BER_TYPE_BITSTRING:
return -1;
case BER_TYPE_OCTETSTRING:
case BER_TYPE_OBJECT:
ber_write(ber, root->be_val, root->be_len);
break;
case BER_TYPE_NULL: /* no payload */
case BER_TYPE_EOC:
break;
case BER_TYPE_SEQUENCE:
case BER_TYPE_SET:
if (root->be_sub && ber_dump_element(ber, root->be_sub) == -1)
return -1;
break;
}
if (root->be_next == NULL)
return 0;
return ber_dump_element(ber, root->be_next);
}
static void
ber_dump_header(struct ber *ber, struct ber_element *root)
{
u_char id = 0, t, buf[8];
unsigned long type;
size_t size;
/* class universal, type encoding depending on type value */
/* length encoding */
if (root->be_type <= BER_TYPE_SINGLE_MAX) {
id = root->be_type | (root->be_class << BER_CLASS_SHIFT);
if (root->be_encoding == BER_TYPE_SEQUENCE ||
root->be_encoding == BER_TYPE_SET)
id |= BER_TYPE_CONSTRUCTED;
ber_putc(ber, id);
} else {
id = BER_TAG_MASK | (root->be_class << BER_CLASS_SHIFT);
if (root->be_encoding == BER_TYPE_SEQUENCE ||
root->be_encoding == BER_TYPE_SET)
id |= BER_TYPE_CONSTRUCTED;
ber_putc(ber, id);
for (t = 0, type = root->be_type; type > 0; type >>= 7)
buf[t++] = type & ~BER_TAG_MORE;
while (t-- > 0) {
if (t > 0)
buf[t] |= BER_TAG_MORE;
ber_putc(ber, buf[t]);
}
}
if (root->be_len < BER_TAG_MORE) {
/* short form */
ber_putc(ber, root->be_len);
} else {
for (t = 0, size = root->be_len; size > 0; size >>= 8)
buf[t++] = size & 0xff;
ber_putc(ber, t | BER_TAG_MORE);
while (t > 0)
ber_putc(ber, buf[--t]);
}
}
static void
ber_putc(struct ber *ber, u_char c)
{
if (ber->br_wptr + 1 <= ber->br_wend)
*ber->br_wptr = c;
ber->br_wptr++;
}
static void
ber_write(struct ber *ber, void *buf, size_t len)
{
if (ber->br_wptr + len <= ber->br_wend)
bcopy(buf, ber->br_wptr, len);
ber->br_wptr += len;
}
/*
* extract a BER encoded tag. There are two types, a short and long form.
*/
static ssize_t
get_id(struct ber *b, unsigned long *tag, int *class, int *cstruct)
{
u_char u;
size_t i = 0;
unsigned long t = 0;
if (ber_getc(b, &u) == -1)
return -1;
*class = (u >> BER_CLASS_SHIFT) & BER_CLASS_MASK;
*cstruct = (u & BER_TYPE_CONSTRUCTED) == BER_TYPE_CONSTRUCTED;
if ((u & BER_TAG_MASK) != BER_TAG_MASK) {
*tag = u & BER_TAG_MASK;
return 1;
}
do {
if (ber_getc(b, &u) == -1)
return -1;
t = (t << 7) | (u & ~BER_TAG_MORE);
i++;
} while (u & BER_TAG_MORE);
if (i > sizeof(unsigned long)) {
errno = ERANGE;
return -1;
}
*tag = t;
return i + 1;
}
/*
* extract length of a ber object -- if length is unknown an error is returned.
*/
static ssize_t
get_len(struct ber *b, ssize_t *len)
{
u_char u, n;
ssize_t s, r;
if (ber_getc(b, &u) == -1)
return -1;
if ((u & BER_TAG_MORE) == 0) {
/* short form */
*len = u;
return 1;
}
n = u & ~BER_TAG_MORE;
if (sizeof(ssize_t) < n) {
errno = ERANGE;
return -1;
}
r = n + 1;
for (s = 0; n > 0; n--) {
if (ber_getc(b, &u) == -1)
return -1;
s = (s << 8) | u;
}
if (s < 0) {
/* overflow */
errno = ERANGE;
return -1;
}
if (s == 0) {
/* invalid encoding */
errno = EINVAL;
return -1;
}
*len = s;
return r;
}
static ssize_t
ber_read_element(struct ber *ber, struct ber_element *elm)
{
long long val = 0;
struct ber_element *next;
unsigned long type;
int i, class, cstruct;
ssize_t len, r, totlen = 0;
u_char c;
if ((r = get_id(ber, &type, &class, &cstruct)) == -1)
return -1;
DPRINTF("ber read got class %d type %lu, %s\n",
class, type, cstruct ? "constructive" : "primitive");
totlen += r;
if ((r = get_len(ber, &len)) == -1)
return -1;
DPRINTF("ber read element size %zd\n", len);
totlen += r + len;
/*
* If using an external buffer and the total size of the element
* is larger, then the external buffer don't bother to continue.
*/
if (ber->fd == -1 && len > ber->br_rend - ber->br_rptr) {
errno = ECANCELED;
return -1;
}
elm->be_type = type;
elm->be_len = len;
elm->be_class = class;
if (elm->be_encoding == 0) {
/* try to figure out the encoding via class, type and cstruct */
if (cstruct)
elm->be_encoding = BER_TYPE_SEQUENCE;
else if (class == BER_CLASS_UNIVERSAL)
elm->be_encoding = type;
else if (ber->br_application != NULL) {
/*
* Ask the application to map the encoding to a
* universal type. For example, a SMI IpAddress
* type is defined as 4 byte OCTET STRING.
*/
elm->be_encoding = (*ber->br_application)(elm);
} else
/* last resort option */
elm->be_encoding = BER_TYPE_NULL;
}
switch (elm->be_encoding) {
case BER_TYPE_EOC: /* End-Of-Content */
break;
case BER_TYPE_BOOLEAN:
case BER_TYPE_INTEGER:
case BER_TYPE_ENUMERATED:
if (len > (ssize_t)sizeof(long long))
return -1;
for (i = 0; i < len; i++) {
if (ber_getc(ber, &c) != 1)
return -1;
val <<= 8;
val |= c;
}
/* sign extend if MSB is set */
if (val >> ((i - 1) * 8) & 0x80)
val |= ULLONG_MAX << (i * 8);
elm->be_numeric = val;
break;
case BER_TYPE_BITSTRING:
elm->be_val = malloc(len);
if (elm->be_val == NULL)
return -1;
elm->be_free = 1;
elm->be_len = len;
ber_read(ber, elm->be_val, len);
break;
case BER_TYPE_OCTETSTRING:
case BER_TYPE_OBJECT:
elm->be_val = malloc(len + 1);
if (elm->be_val == NULL)
return -1;
elm->be_free = 1;
elm->be_len = len;
ber_read(ber, elm->be_val, len);
((u_char *)elm->be_val)[len] = '\0';
break;
case BER_TYPE_NULL: /* no payload */
if (len != 0)
return -1;
break;
case BER_TYPE_SEQUENCE:
case BER_TYPE_SET:
if (elm->be_sub == NULL) {
if ((elm->be_sub = ber_get_element(0)) == NULL)
return -1;
}
next = elm->be_sub;
while (len > 0) {
r = ber_read_element(ber, next);
if (r == -1)
return -1;
len -= r;
if (len > 0 && next->be_next == NULL) {
if ((next->be_next = ber_get_element(0)) ==
NULL)
return -1;
}
next = next->be_next;
}
break;
}
return totlen;
}
static ssize_t
ber_readbuf(struct ber *b, void *buf, size_t nbytes)
{
size_t sz;
size_t len;
if (b->br_rbuf == NULL)
return -1;
sz = b->br_rend - b->br_rptr;
len = MINIMUM(nbytes, sz);
if (len == 0) {
errno = ECANCELED;
return (-1); /* end of buffer and parser wants more data */
}
bcopy(b->br_rptr, buf, len);
b->br_rptr += len;
return (len);
}
void
ber_set_readbuf(struct ber *b, void *buf, size_t len)
{
b->br_rbuf = b->br_rptr = buf;
b->br_rend = (u_int8_t *)buf + len;
}
ssize_t
ber_get_writebuf(struct ber *b, void **buf)
{
if (b->br_wbuf == NULL)
return -1;
*buf = b->br_wbuf;
return (b->br_wend - b->br_wbuf);
}
void
ber_set_application(struct ber *b, unsigned long (*cb)(struct ber_element *))
{
b->br_application = cb;
}
void
ber_free(struct ber *b)
{
free(b->br_wbuf);
}
static ssize_t
ber_getc(struct ber *b, u_char *c)
{
ssize_t r;
/*
* XXX calling read here is wrong in many ways. The most obvious one
* being that we will block till data arrives.
* But for now it is _good enough_ *gulp*
*/
if (b->fd == -1)
r = ber_readbuf(b, c, 1);
else
r = read(b->fd, c, 1);
return r;
}
static ssize_t
ber_read(struct ber *ber, void *buf, size_t len)
{
u_char *b = buf;
ssize_t r, remain = len;
/*
* XXX calling read here is wrong in many ways. The most obvious one
* being that we will block till data arrives.
* But for now it is _good enough_ *gulp*
*/
while (remain > 0) {
if (ber->fd == -1)
r = ber_readbuf(ber, b, remain);
else
r = read(ber->fd, b, remain);
if (r == -1) {
if (errno == EINTR || errno == EAGAIN)
continue;
return -1;
}
if (r == 0)
return (b - (u_char *)buf);
b += r;
remain -= r;
}
return (b - (u_char *)buf);
}
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