wireshark/asn1.c
Guy Harris 60f9476740 Rename "asn1_octet_string_value_decode()" to
"asn1_string_value_decode()", as it can be used for various character
string types as well.

Turn "asn1_octet_string_decode()" into "asn1_string_decode()", which
takes an additional argument giving the tag expected for the string in
question, and make "asn1_octet_string_decode()" a wrapper around it.

Clean up the ASN.1 dissection in the Kerberos dissector, making more use
of the code in "asn1.c", wrapping more operations up in macros, and
doing some more type checking.

Use "REP" rather than "RESP" in names and strings; "REP" is what the
Kerberos spec uses.

Make the routines in the Kerberos dissector not used outside that
dissector static.

Fix some problems with the dissection of strings in the Kerberos
dissector (it was extracting the data from the wrong place in the
packet).

In Kerberos V5, the "kvno" item in the EncryptedData type is optional;
treat it as such.

Treat integers as unsigned in the Kerberos dissector.

svn path=/trunk/; revision=2777
2000-12-24 09:10:12 +00:00

936 lines
27 KiB
C

/* asn1.c
* Routines for ASN.1 BER dissection
*
* $Id: asn1.c,v 1.6 2000/12/24 09:10:11 guy Exp $
*
* Ethereal - Network traffic analyzer
* By Gerald Combs <gerald@zing.org>
*
* Based on "g_asn1.c" from:
*
* GXSNMP -- An snmp mangament application
* Copyright (C) 1998 Gregory McLean & Jochen Friedrich
* Beholder RMON ethernet network monitor, Copyright (C) 1993 DNPAP group
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*
*/
/*
* MODULE INFORMATION
* ------------------
* FILE NAME: g_asn1.c
* SYSTEM NAME: ASN1 Basic Encoding
* ORIGINAL AUTHOR(S): Dirk Wisse
* VERSION NUMBER: 1
* CREATION DATE: 1990/11/22
*
* DESCRIPTION: ASN1 Basic Encoding Rules.
*
* To decode this we must do:
*
* asn1_open (asn1, buf_start, buf_len);
* asn1_header_decode (asn1, &end_of_seq, cls, con, tag, def, len);
* asn1_header_decode (asn1, &end_of_octs, cls, con, tag, def, len);
* asn1_octets_decode (asn1, end_of_octs, str, len);
* asn1_header_decode (asn1, &end_of_int, cls, con, tag);
* asn1_int_decode (asn1, end_of_int, &integer);
* asn1_eoc_decode (asn1, end_of_seq);
* asn1_close (asn1, &buf_start, &buf_len);
*
* For indefinite encoding end_of_seq and &end_of_seq in the
* example above should be replaced by NULL.
* For indefinite decoding nothing has to be changed.
* This can be very useful if you want to decode both
* definite and indefinite encodings.
*/
#ifdef HAVE_CONFIG_H
# include "config.h"
#endif
#ifdef HAVE_SYS_TYPES_H
# include <sys/types.h>
#endif
#ifdef HAVE_WINSOCK_H
#include <winsock.h>
#endif
#include <glib.h>
#include "asn1.h"
/*
* NAME: asn1_open [API]
* SYNOPSIS: void asn1_open
* (
* ASN1_SCK *asn1,
* const guchar *buf,
* guint len,
* )
* DESCRIPTION: Opens an ASN1 socket.
* Parameters:
* asn1: pointer to ASN1 socket.
* buf: Character buffer for encoding.
* len: Length of character buffer.
* Encoding starts at the end of the buffer, and
* proceeds to the beginning.
* RETURNS: void
*/
void
asn1_open(ASN1_SCK *asn1, const guchar *buf, guint len)
{
asn1->begin = buf;
asn1->end = buf + len;
asn1->pointer = buf;
}
/*
* NAME: asn1_close [API]
* SYNOPSIS: void asn1_close
* (
* ASN1_SCK *asn1,
* guchar **buf,
* guint *len
* )
* DESCRIPTION: Closes an ASN1 socket.
* Parameters:
* asn1: pointer to ASN1 socket.
* buf: pointer to beginning of encoding.
* len: Length of encoding.
* RETURNS: void
*/
void
asn1_close(ASN1_SCK *asn1, const guchar **buf, guint *len)
{
*buf = asn1->pointer;
*len = asn1->end - asn1->pointer;
}
/*
* NAME: asn1_octet_decode
* SYNOPSIS: int asn1_octet_decode
* (
* ASN1_SCK *asn1,
* guchar *ch
* )
* DESCRIPTION: Decodes an octet.
* RETURNS: ASN1_ERR value (ASN1_ERR_NOERROR on success)
*/
int
asn1_octet_decode(ASN1_SCK *asn1, guchar *ch)
{
if (asn1->pointer >= asn1->end)
return ASN1_ERR_EMPTY;
*ch = *(asn1->pointer)++;
return ASN1_ERR_NOERROR;
}
/*
* NAME: asn1_tag_decode
* SYNOPSIS: int asn1_tag_decode
* (
* ASN1_SCK *asn1,
* guint *tag
* )
* DESCRIPTION: Decodes a tag.
* RETURNS: ASN1_ERR value (ASN1_ERR_NOERROR on success)
*/
int
asn1_tag_decode(ASN1_SCK *asn1, guint *tag)
{
int ret;
guchar ch;
*tag = 0;
do {
ret = asn1_octet_decode (asn1, &ch);
if (ret != ASN1_ERR_NOERROR)
return ret;
*tag <<= 7;
*tag |= ch & 0x7F;
} while ((ch & 0x80) == 0x80);
return ASN1_ERR_NOERROR;
}
/*
* NAME: asn1_id_decode
* SYNOPSIS: int asn1_id_decode
* (
* ASN1_SCK *asn1,
* guint *cls,
* guint *con,
* guint *tag
* )
* DESCRIPTION: Decodes an identifier.
* RETURNS: ASN1_ERR value (ASN1_ERR_NOERROR on success)
*/
int
asn1_id_decode(ASN1_SCK *asn1, guint *cls, guint *con, guint *tag)
{
int ret;
guchar ch;
ret = asn1_octet_decode (asn1, &ch);
if (ret != ASN1_ERR_NOERROR)
return ret;
*cls = (ch & 0xC0) >> 6;
*con = (ch & 0x20) >> 5;
*tag = (ch & 0x1F);
if (*tag == 0x1F) {
ret = asn1_tag_decode (asn1, tag);
if (ret != ASN1_ERR_NOERROR)
return ret;
}
return ASN1_ERR_NOERROR;
}
/*
* NAME: asn1_length_decode
* SYNOPSIS: int asn1_length_decode
* (
* ASN1_SCK *asn1,
* gboolean *def,
* guint *len
* )
* DESCRIPTION: Decodes an ASN1 length.
* Parameters:
* asn1: pointer to ASN1 socket.
* def: Boolean - TRUE if length definite, FALSE if not
* len: length, if length is definite
* DESCRIPTION: Decodes a definite or indefinite length.
* RETURNS: ASN1_ERR value (ASN1_ERR_NOERROR on success)
*/
int
asn1_length_decode(ASN1_SCK *asn1, gboolean *def, guint *len)
{
int ret;
guchar ch, cnt;
ret = asn1_octet_decode (asn1, &ch);
if (ret != ASN1_ERR_NOERROR)
return ret;
if (ch == 0x80)
*def = FALSE; /* indefinite length */
else {
*def = TRUE; /* definite length */
if (ch < 0x80)
*len = ch;
else {
cnt = (guchar) (ch & 0x7F);
*len = 0;
while (cnt > 0) {
ret = asn1_octet_decode (asn1, &ch);
if (ret != ASN1_ERR_NOERROR)
return ret;
*len <<= 8;
*len |= ch;
cnt--;
}
}
}
return ASN1_ERR_NOERROR;
}
/*
* NAME: asn1_header_decode [API]
* SYNOPSIS: int asn1_header_decode
* (
* ASN1_SCK *asn1,
* guint *cls,
* guint *con,
* guint *tag
* gboolean *defp,
* guint *lenp
* )
* DESCRIPTION: Decodes an ASN1 header.
* Parameters:
* asn1: pointer to ASN1 socket.
* cls: Class (see asn1.h)
* con: Primitive, Constructed (ASN1_PRI, ASN1_CON)
* tag: Tag (see asn1.h)
* defp: Boolean - TRUE if length definite, FALSE if not
* lenp: length, if length is definite
* RETURNS: ASN1_ERR value (ASN1_ERR_NOERROR on success)
*/
int
asn1_header_decode(ASN1_SCK *asn1, guint *cls, guint *con, guint *tag,
gboolean *defp, guint *lenp)
{
int ret;
guint def, len;
ret = asn1_id_decode (asn1, cls, con, tag);
if (ret != ASN1_ERR_NOERROR)
return ret;
ret = asn1_length_decode (asn1, &def, &len);
if (ret != ASN1_ERR_NOERROR)
return ret;
*defp = def;
*lenp = len;
return ASN1_ERR_NOERROR;
}
/*
* NAME: asn1_eoc [API]
* SYNOPSIS: gboolean asn1_eoc
* (
* ASN1_SCK *asn1,
* guchar *eoc
* )
* DESCRIPTION: Checks if decoding is at End Of Contents.
* Parameters:
* asn1: pointer to ASN1 socket.
* eoc: pointer to end of encoding or 0 if
* indefinite.
* RETURNS: gboolean success
*/
gboolean
asn1_eoc ( ASN1_SCK *asn1, const guchar *eoc)
{
if (eoc == 0)
return (asn1->pointer [0] == 0x00 && asn1->pointer [1] == 0x00);
else
return (asn1->pointer >= eoc);
}
/*
* NAME: asn1_eoc_decode [API]
* SYNOPSIS: int asn1_eoc_decode
* (
* ASN1_SCK *asn1,
* guchar *eoc
* )
* DESCRIPTION: Decodes End Of Contents.
* Parameters:
* asn1: pointer to ASN1 socket.
* eoc: pointer to end of encoding or 0 if
* indefinite.
* If eoc is 0 it decodes an ASN1 End Of
* Contents (0x00 0x00), so it has to be an
* indefinite length encoding. If eoc is a
* character pointer, it probably was filled by
* asn1_header_decode, and should point to the octet
* after the last of the encoding. It is checked
* if this pointer points to the octet to be
* decoded. This only takes place in decoding a
* definite length encoding.
* RETURNS: ASN1_ERR value (ASN1_ERR_NOERROR on success)
*/
int
asn1_eoc_decode (ASN1_SCK *asn1, const guchar *eoc)
{
int ret;
guchar ch;
if (eoc == 0) {
ret = asn1_octet_decode (asn1, &ch);
if (ret != ASN1_ERR_NOERROR)
return ret;
if (ch != 0x00)
return ASN1_ERR_EOC_MISMATCH;
ret = asn1_octet_decode (asn1, &ch);
if (ret != ASN1_ERR_NOERROR)
return ret;
if (ch != 0x00)
return ASN1_ERR_EOC_MISMATCH;
return ASN1_ERR_NOERROR;
} else {
if (asn1->pointer != eoc)
return ASN1_ERR_LENGTH_MISMATCH;
return ASN1_ERR_NOERROR;
}
}
/*
* NAME: asn1_null_decode [API]
* SYNOPSIS: int asn1_null_decode
* (
* ASN1_SCK *asn1,
* int enc_len
* )
* DESCRIPTION: Decodes Null.
* Parameters:
* asn1: pointer to ASN1 socket.
* enc_len: length of encoding of value.
* RETURNS: ASN1_ERR value (ASN1_ERR_NOERROR on success)
*/
int
asn1_null_decode ( ASN1_SCK *asn1, int enc_len)
{
asn1->pointer += enc_len;
return ASN1_ERR_NOERROR;
}
/*
* NAME: asn1_bool_decode [API]
* SYNOPSIS: int asn1_bool_decode
* (
* ASN1_SCK *asn1,
* int enc_len,
* gboolean *bool
* )
* DESCRIPTION: Decodes Boolean.
* Parameters:
* asn1: pointer to ASN1 socket.
* enc_len: length of encoding of value.
* bool: False, True (0, !0).
* RETURNS: ASN1_ERR value (ASN1_ERR_NOERROR on success)
*/
int
asn1_bool_decode ( ASN1_SCK *asn1, int enc_len, gboolean *bool)
{
int ret;
guchar ch;
if (enc_len != 1)
return ASN1_ERR_LENGTH_MISMATCH;
ret = asn1_octet_decode (asn1, &ch);
if (ret != ASN1_ERR_NOERROR)
return ret;
*bool = ch ? TRUE : FALSE;
return ASN1_ERR_NOERROR;
}
/*
* NAME: asn1_int32_value_decode [API]
* SYNOPSIS: int asn1_int32_value_decode
* (
* ASN1_SCK *asn1,
* int enc_len,
* gint32 *integer
* )
* DESCRIPTION: Decodes value portion of Integer (which must be no more
* than 32 bits).
* Parameters:
* asn1: pointer to ASN1 socket.
* enc_len: length of encoding of value.
* integer: Integer.
* RETURNS: ASN1_ERR value (ASN1_ERR_NOERROR on success)
*/
int
asn1_int32_value_decode ( ASN1_SCK *asn1, int enc_len, gint32 *integer)
{
int ret;
const guchar *eoc;
guchar ch;
guint len;
eoc = asn1->pointer + enc_len;
ret = asn1_octet_decode (asn1, &ch);
if (ret != ASN1_ERR_NOERROR)
return ret;
*integer = (gint) ch;
len = 1;
while (asn1->pointer < eoc) {
if (++len > sizeof (gint32))
return ASN1_ERR_WRONG_LENGTH_FOR_TYPE;
ret = asn1_octet_decode (asn1, &ch);
if (ret != ASN1_ERR_NOERROR)
return ret;
*integer <<= 8;
*integer |= ch;
}
return ASN1_ERR_NOERROR;
}
/*
* NAME: asn1_int32_decode [API]
* SYNOPSIS: int asn1_int32_decode
* (
* ASN1_SCK *asn1,
* gint32 *integer,
* guint *nbytes,
* )
* DESCRIPTION: Decodes Integer (which must be no more than 32 bits).
* Parameters:
* asn1: pointer to ASN1 socket.
* integer: Integer.
* nbytes: number of bytes used to encode it.
* RETURNS: ASN1_ERR value (ASN1_ERR_NOERROR on success)
*/
int
asn1_int32_decode ( ASN1_SCK *asn1, gint32 *integer, guint *nbytes)
{
int ret;
const guchar *start;
guint cls;
guint con;
guint tag;
gboolean def;
guint enc_len;
start = asn1->pointer;
ret = asn1_header_decode (asn1, &cls, &con, &tag, &def, &enc_len);
if (ret != ASN1_ERR_NOERROR)
goto done;
if (cls != ASN1_UNI || con != ASN1_PRI || tag != ASN1_INT) {
ret = ASN1_ERR_WRONG_TYPE;
goto done;
}
if (!def) {
ret = ASN1_ERR_LENGTH_NOT_DEFINITE;
goto done;
}
ret = asn1_int32_value_decode (asn1, enc_len, integer);
done:
*nbytes = asn1->pointer - start;
return ret;
}
/*
* NAME: asn1_uint32_value_decode [API]
* SYNOPSIS: int asn1_uint32_value_decode
* (
* ASN1_SCK *asn1,
* int enc_len,
* guint32 *integer
* )
* DESCRIPTION: Decodes value part of Unsigned Integer (which must be no
* more than 32 bits).
* Parameters:
* asn1: pointer to ASN1 socket.
* enc_len: length of encoding of value.
* integer: Integer.
* RETURNS: ASN1_ERR value (ASN1_ERR_NOERROR on success)
*/
int
asn1_uint32_value_decode ( ASN1_SCK *asn1, int enc_len, guint *integer)
{
int ret;
const guchar *eoc;
guchar ch;
guint len;
eoc = asn1->pointer + enc_len;
ret = asn1_octet_decode (asn1, &ch);
if (ret != ASN1_ERR_NOERROR)
return ret;
*integer = ch;
if (ch == 0)
len = 0;
else
len = 1;
while (asn1->pointer < eoc) {
if (++len > sizeof (guint32))
return ASN1_ERR_WRONG_LENGTH_FOR_TYPE;
ret = asn1_octet_decode (asn1, &ch);
if (ret != ASN1_ERR_NOERROR)
return ret;
*integer <<= 8;
*integer |= ch;
}
return ASN1_ERR_NOERROR;
}
/*
* NAME: asn1_uint32_decode [API]
* SYNOPSIS: int asn1_uint32_decode
* (
* ASN1_SCK *asn1,
* guint32 *integer,
* guint *nbytes,
* )
* DESCRIPTION: Decodes Unsigned Integer (which must be no more than 32 bits).
* Parameters:
* asn1: pointer to ASN1 socket.
* integer: Integer.
* nbytes: number of bytes used to encode it.
* RETURNS: ASN1_ERR value (ASN1_ERR_NOERROR on success)
*/
int
asn1_uint32_decode ( ASN1_SCK *asn1, guint32 *integer, guint *nbytes)
{
int ret;
const guchar *start;
guint cls;
guint con;
guint tag;
gboolean def;
guint enc_len;
start = asn1->pointer;
ret = asn1_header_decode (asn1, &cls, &con, &tag, &def, &enc_len);
if (ret != ASN1_ERR_NOERROR)
goto done;
if (cls != ASN1_UNI || con != ASN1_PRI || tag != ASN1_INT) {
ret = ASN1_ERR_WRONG_TYPE;
goto done;
}
if (!def) {
ret = ASN1_ERR_LENGTH_NOT_DEFINITE;
goto done;
}
ret = asn1_uint32_value_decode (asn1, enc_len, integer);
done:
*nbytes = asn1->pointer - start;
return ret;
}
/*
* NAME: asn1_bits_decode [API]
* SYNOPSIS: int asn1_bits_decode
* (
* ASN1_SCK *asn1,
* guchar *eoc,
* guchar *bits,
* guint size,
* guint len,
* guchar unused
* )
* DESCRIPTION: Decodes Bit String.
* Parameters:
* asn1: pointer to ASN1 socket.
* eoc: pointer to end of encoding or 0 if
* indefinite.
* bits: pointer to begin of Bit String.
* size: Size of Bit String in characters.
* len: Length of Bit String in characters.
* unused: Number of unused bits in last character.
* RETURNS: ASN1_ERR value (ASN1_ERR_NOERROR on success)
*/
int
asn1_bits_decode ( ASN1_SCK *asn1, const guchar *eoc, guchar **bits,
guint *len, guchar *unused)
{
int ret;
*bits = NULL;
ret = asn1_octet_decode (asn1, unused);
if (ret != ASN1_ERR_NOERROR)
return ret;
*len = 0;
*bits = g_malloc(eoc - asn1->pointer);
while (asn1->pointer < eoc) {
ret = asn1_octet_decode (asn1, (guchar *)bits++);
if (ret != ASN1_ERR_NOERROR) {
g_free(*bits);
*bits = NULL;
return ret;
}
}
return ASN1_ERR_NOERROR;
}
/*
* NAME: asn1_string_value_decode [API]
* SYNOPSIS: int asn1_string_value_decode
* (
* ASN1_SCK *asn1,
* int enc_len,
* guchar **octets
* )
* DESCRIPTION: Decodes value portion of string (Octet String, various
* character string types)
* Parameters:
* asn1: pointer to ASN1 socket.
* enc_len: length of encoding of value.
* octets: pointer to variable we set to point to string.
* RETURNS: ASN1_ERR value (ASN1_ERR_NOERROR on success)
*/
int
asn1_string_value_decode ( ASN1_SCK *asn1, int enc_len, guchar **octets)
{
int ret;
const guchar *eoc;
guchar *ptr;
eoc = asn1->pointer + enc_len;
*octets = g_malloc (enc_len);
ptr = *octets;
while (asn1->pointer < eoc) {
ret = asn1_octet_decode (asn1, (guchar *)ptr++);
if (ret != ASN1_ERR_NOERROR) {
g_free(*octets);
*octets = NULL;
return ret;
}
}
return ASN1_ERR_NOERROR;
}
/*
* NAME: asn1_string_decode [API]
* SYNOPSIS: int asn1_string_decode
* (
* ASN1_SCK *asn1,
* guchar **octets,
* guint *str_len,
* guint *nbytes,
* guint expected_tag
* )
* DESCRIPTION: Decodes string (Octet String, various character string
* types)
* Parameters:
* asn1: pointer to ASN1 socket.
* octets: pointer to variable we set to point to string.
* str_len: length of octet_string.
* nbytes: number of bytes used to encode.
* expected_tag: tag expected for this type of string.
* RETURNS: ASN1_ERR value (ASN1_ERR_NOERROR on success)
*/
int
asn1_string_decode ( ASN1_SCK *asn1, guchar **octets, guint *str_len,
guint *nbytes, guint expected_tag)
{
int ret;
const guchar *start;
int enc_len;
guint cls;
guint con;
guint tag;
gboolean def;
start = asn1->pointer;
ret = asn1_header_decode (asn1, &cls, &con, &tag, &def, &enc_len);
if (ret != ASN1_ERR_NOERROR)
goto done;
if (cls != ASN1_UNI || con != ASN1_PRI || tag != expected_tag) {
/* XXX - handle the constructed encoding? */
ret = ASN1_ERR_WRONG_TYPE;
goto done;
}
if (!def) {
ret = ASN1_ERR_LENGTH_NOT_DEFINITE;
goto done;
}
ret = asn1_string_value_decode (asn1, enc_len, octets);
*str_len = enc_len;
done:
*nbytes = asn1->pointer - start;
return ret;
}
/*
* NAME: asn1_octet_string_decode [API]
* SYNOPSIS: int asn1_octet_string_decode
* (
* ASN1_SCK *asn1,
* guchar **octets,
* guint *str_len,
* guint *nbytes,
* )
* DESCRIPTION: Decodes Octet String.
* Parameters:
* asn1: pointer to ASN1 socket.
* octets: pointer to variable we set to point to string.
* str_len: length of octet_string.
* nbytes: number of bytes used to encode.
* RETURNS: ASN1_ERR value (ASN1_ERR_NOERROR on success)
*/
int
asn1_octet_string_decode ( ASN1_SCK *asn1, guchar **octets, guint *str_len,
guint *nbytes)
{
return asn1_string_decode(asn1, octets, str_len, nbytes, ASN1_OTS);
}
/*
* NAME: asn1_subid_decode
* SYNOPSIS: int asn1_subid_decode
* (
* ASN1_SCK *asn1,
* subid_t *subid
* )
* DESCRIPTION: Decodes Sub Identifier.
* Parameters:
* asn1: pointer to ASN1 socket.
* subid: Sub Identifier.
* RETURNS: ASN1_ERR value (ASN1_ERR_NOERROR on success)
*/
int
asn1_subid_decode ( ASN1_SCK *asn1, subid_t *subid)
{
int ret;
guchar ch;
*subid = 0;
do {
ret = asn1_octet_decode(asn1, &ch);
if (ret != ASN1_ERR_NOERROR)
return ret;
*subid <<= 7;
*subid |= ch & 0x7F;
} while ((ch & 0x80) == 0x80);
return ASN1_ERR_NOERROR;
}
/*
* NAME: asn1_oid_value_decode [API]
* SYNOPSIS: int asn1_oid_value_decode
* (
* ASN1_SCK *asn1,
* int enc_len,
* subid_t **oid,
* guint *len
* )
* DESCRIPTION: Decodes value portion of Object Identifier.
* Parameters:
* asn1: pointer to ASN1 socket.
* enc_len: length of encoding of value.
* oid: pointer to variable we set to Object Identifier.
* len: Length of Object Identifier in gulongs.
* RETURNS: ASN1_ERR value (ASN1_ERR_NOERROR on success)
*/
int
asn1_oid_value_decode ( ASN1_SCK *asn1, int enc_len, subid_t **oid, guint *len)
{
int ret;
const guchar *eoc;
subid_t subid;
guint size;
subid_t *optr;
eoc = asn1->pointer + enc_len;
size = enc_len + 1;
*oid = g_malloc(size * sizeof(gulong));
optr = *oid;
ret = asn1_subid_decode (asn1, &subid);
if (ret != ASN1_ERR_NOERROR) {
g_free(*oid);
*oid = NULL;
return ret;
}
if (subid < 40) {
optr[0] = 0;
optr[1] = subid;
} else if (subid < 80) {
optr[0] = 1;
optr[1] = subid - 40;
} else {
optr[0] = 2;
optr[1] = subid - 80;
}
*len = 2;
optr += 2;
while (asn1->pointer < eoc) {
if (++(*len) > size) {
g_free(*oid);
*oid = NULL;
return ASN1_ERR_WRONG_LENGTH_FOR_TYPE;
}
ret = asn1_subid_decode (asn1, optr++);
if (ret != ASN1_ERR_NOERROR) {
g_free(*oid);
*oid = NULL;
return ret;
}
}
return ASN1_ERR_NOERROR;
}
/*
* NAME: asn1_oid_decode [API]
* SYNOPSIS: int asn1_oid_decode
* (
* ASN1_SCK *asn1,
* subid_t **oid,
* guint *len,
* guint *nbytes
* )
* DESCRIPTION: Decodes Object Identifier.
* Parameters:
* asn1: pointer to ASN1 socket.
* oid: pointer to variable we set to Object Identifier.
* len: Length of Object Identifier in gulongs.
* nbytes: number of bytes used to encode.
* RETURNS: ASN1_ERR value (ASN1_ERR_NOERROR on success)
*/
int
asn1_oid_decode ( ASN1_SCK *asn1, subid_t **oid, guint *len, guint *nbytes)
{
int ret;
const guchar *start;
guint cls;
guint con;
guint tag;
gboolean def;
guint enc_len;
start = asn1->pointer;
ret = asn1_header_decode (asn1, &cls, &con, &tag, &def, &enc_len);
if (ret != ASN1_ERR_NOERROR)
goto done;
if (cls != ASN1_UNI || con != ASN1_PRI || tag != ASN1_OJI) {
ret = ASN1_ERR_WRONG_TYPE;
goto done;
}
if (!def) {
ret = ASN1_ERR_LENGTH_NOT_DEFINITE;
goto done;
}
ret = asn1_oid_value_decode (asn1, enc_len, oid, len);
done:
*nbytes = asn1->pointer - start;
return ret;
}
/*
* NAME: asn1_sequence_decode [API]
* SYNOPSIS: int asn1_sequence_decode
* (
* ASN1_SCK *asn1,
* guint *seq_len,
* guint *nbytes
* )
* DESCRIPTION: Decodes header for SEQUENCE.
* Parameters:
* asn1: pointer to ASN1 socket.
* seq_len: length of sequence.
* nbytes: number of bytes used to encode header.
* RETURNS: ASN1_ERR value (ASN1_ERR_NOERROR on success)
*/
int
asn1_sequence_decode ( ASN1_SCK *asn1, guint *seq_len, guint *nbytes)
{
int ret;
const guchar *start;
guint cls;
guint con;
guint tag;
gboolean def;
start = asn1->pointer;
ret = asn1_header_decode(asn1, &cls, &con, &tag,
&def, seq_len);
if (ret != ASN1_ERR_NOERROR)
goto done;
if (cls != ASN1_UNI || con != ASN1_CON || tag != ASN1_SEQ) {
ret = ASN1_ERR_WRONG_TYPE;
goto done;
}
if (!def) {
/* XXX - might some sequences have an indefinite length? */
ret = ASN1_ERR_LENGTH_NOT_DEFINITE;
goto done;
}
ret = ASN1_ERR_NOERROR;
done:
*nbytes = asn1->pointer - start;
return ret;
}