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			348 lines
		
	
	
		
			11 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			348 lines
		
	
	
		
			11 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /**
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|  * \file asn1.h
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|  *
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|  * \brief Generic ASN.1 parsing
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|  *
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|  *  Copyright (C) 2006-2013, Brainspark B.V.
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|  *
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|  *  This file is part of PolarSSL (http://www.polarssl.org)
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|  *  Lead Maintainer: Paul Bakker <polarssl_maintainer at polarssl.org>
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|  *
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|  *  All rights reserved.
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|  *
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|  *  This program is free software; you can redistribute it and/or modify
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|  *  it under the terms of the GNU General Public License as published by
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|  *  the Free Software Foundation; either version 2 of the License, or
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|  *  (at your option) any later version.
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|  *
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|  *  This program is distributed in the hope that it will be useful,
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|  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
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|  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
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|  *  GNU General Public License for more details.
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|  *
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|  *  You should have received a copy of the GNU General Public License along
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|  *  with this program; if not, write to the Free Software Foundation, Inc.,
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|  *  51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
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|  */
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| #ifndef POLARSSL_ASN1_H
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| #define POLARSSL_ASN1_H
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| 
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| #if !defined(POLARSSL_CONFIG_FILE)
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| #include "config.h"
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| #else
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| #include POLARSSL_CONFIG_FILE
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| #endif
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| 
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| #if defined(POLARSSL_BIGNUM_C)
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| #include "bignum.h"
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| #endif
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| 
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| #include <string.h>
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| 
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| /**
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|  * \addtogroup asn1_module
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|  * \{
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|  */
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| 
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| /**
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|  * \name ASN1 Error codes
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|  * These error codes are OR'ed to X509 error codes for
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|  * higher error granularity.
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|  * ASN1 is a standard to specify data structures.
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|  * \{
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|  */
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| #define POLARSSL_ERR_ASN1_OUT_OF_DATA                      -0x0060  /**< Out of data when parsing an ASN1 data structure. */
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| #define POLARSSL_ERR_ASN1_UNEXPECTED_TAG                   -0x0062  /**< ASN1 tag was of an unexpected value. */
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| #define POLARSSL_ERR_ASN1_INVALID_LENGTH                   -0x0064  /**< Error when trying to determine the length or invalid length. */
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| #define POLARSSL_ERR_ASN1_LENGTH_MISMATCH                  -0x0066  /**< Actual length differs from expected length. */
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| #define POLARSSL_ERR_ASN1_INVALID_DATA                     -0x0068  /**< Data is invalid. (not used) */
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| #define POLARSSL_ERR_ASN1_MALLOC_FAILED                    -0x006A  /**< Memory allocation failed */
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| #define POLARSSL_ERR_ASN1_BUF_TOO_SMALL                    -0x006C  /**< Buffer too small when writing ASN.1 data structure. */
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| 
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| /* \} name */
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| 
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| /**
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|  * \name DER constants
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|  * These constants comply with DER encoded the ANS1 type tags.
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|  * DER encoding uses hexadecimal representation.
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|  * An example DER sequence is:\n
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|  * - 0x02 -- tag indicating INTEGER
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|  * - 0x01 -- length in octets
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|  * - 0x05 -- value
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|  * Such sequences are typically read into \c ::x509_buf.
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|  * \{
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|  */
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| #define ASN1_BOOLEAN                 0x01
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| #define ASN1_INTEGER                 0x02
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| #define ASN1_BIT_STRING              0x03
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| #define ASN1_OCTET_STRING            0x04
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| #define ASN1_NULL                    0x05
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| #define ASN1_OID                     0x06
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| #define ASN1_UTF8_STRING             0x0C
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| #define ASN1_SEQUENCE                0x10
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| #define ASN1_SET                     0x11
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| #define ASN1_PRINTABLE_STRING        0x13
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| #define ASN1_T61_STRING              0x14
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| #define ASN1_IA5_STRING              0x16
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| #define ASN1_UTC_TIME                0x17
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| #define ASN1_GENERALIZED_TIME        0x18
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| #define ASN1_UNIVERSAL_STRING        0x1C
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| #define ASN1_BMP_STRING              0x1E
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| #define ASN1_PRIMITIVE               0x00
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| #define ASN1_CONSTRUCTED             0x20
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| #define ASN1_CONTEXT_SPECIFIC        0x80
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| /* \} name */
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| /* \} addtogroup asn1_module */
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| 
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| /** Returns the size of the binary string, without the trailing \\0 */
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| #define OID_SIZE(x) (sizeof(x) - 1)
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| 
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| /**
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|  * Compares an asn1_buf structure to a reference OID.
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|  *
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|  * Only works for 'defined' oid_str values (OID_HMAC_SHA1), you cannot use a
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|  * 'unsigned char *oid' here!
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|  *
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|  * Warning: returns true when the OIDs are equal (unlike memcmp)!
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|  */
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| #define OID_CMP(oid_str, oid_buf)                                   \
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|         ( ( OID_SIZE(oid_str) == (oid_buf)->len ) &&                \
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|           memcmp( (oid_str), (oid_buf)->p, (oid_buf)->len) == 0 )
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| 
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| #ifdef __cplusplus
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| extern "C" {
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| #endif
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| 
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| /**
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|  * \name Functions to parse ASN.1 data structures
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|  * \{
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|  */
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| 
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| /**
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|  * Type-length-value structure that allows for ASN1 using DER.
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|  */
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| typedef struct _asn1_buf
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| {
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|     int tag;                /**< ASN1 type, e.g. ASN1_UTF8_STRING. */
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|     size_t len;             /**< ASN1 length, e.g. in octets. */
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|     unsigned char *p;       /**< ASN1 data, e.g. in ASCII. */
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| }
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| asn1_buf;
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| 
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| /**
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|  * Container for ASN1 bit strings.
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|  */
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| typedef struct _asn1_bitstring
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| {
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|     size_t len;                 /**< ASN1 length, e.g. in octets. */
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|     unsigned char unused_bits;  /**< Number of unused bits at the end of the string */
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|     unsigned char *p;           /**< Raw ASN1 data for the bit string */
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| }
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| asn1_bitstring;
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| 
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| /**
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|  * Container for a sequence of ASN.1 items
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|  */
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| typedef struct _asn1_sequence
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| {
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|     asn1_buf buf;                   /**< Buffer containing the given ASN.1 item. */
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|     struct _asn1_sequence *next;    /**< The next entry in the sequence. */
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| }
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| asn1_sequence;
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| 
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| /**
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|  * Container for a sequence or list of 'named' ASN.1 data items
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|  */
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| typedef struct _asn1_named_data
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| {
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|     asn1_buf oid;                   /**< The object identifier. */
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|     asn1_buf val;                   /**< The named value. */
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|     struct _asn1_named_data *next;  /**< The next entry in the sequence. */
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| }
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| asn1_named_data;
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| 
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| /**
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|  * \brief       Get the length of an ASN.1 element.
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|  *              Updates the pointer to immediately behind the length.
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|  *
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|  * \param p     The position in the ASN.1 data
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|  * \param end   End of data
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|  * \param len   The variable that will receive the value
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|  *
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|  * \return      0 if successful, POLARSSL_ERR_ASN1_OUT_OF_DATA on reaching
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|  *              end of data, POLARSSL_ERR_ASN1_INVALID_LENGTH if length is
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|  *              unparseable.
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|  */
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| int asn1_get_len( unsigned char **p,
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|                   const unsigned char *end,
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|                   size_t *len );
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| 
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| /**
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|  * \brief       Get the tag and length of the tag. Check for the requested tag.
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|  *              Updates the pointer to immediately behind the tag and length.
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|  *
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|  * \param p     The position in the ASN.1 data
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|  * \param end   End of data
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|  * \param len   The variable that will receive the length
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|  * \param tag   The expected tag
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|  *
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|  * \return      0 if successful, POLARSSL_ERR_ASN1_UNEXPECTED_TAG if tag did
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|  *              not match requested tag, or another specific ASN.1 error code.
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|  */
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| int asn1_get_tag( unsigned char **p,
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|                   const unsigned char *end,
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|                   size_t *len, int tag );
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| 
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| /**
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|  * \brief       Retrieve a boolean ASN.1 tag and its value.
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|  *              Updates the pointer to immediately behind the full tag.
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|  *
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|  * \param p     The position in the ASN.1 data
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|  * \param end   End of data
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|  * \param val   The variable that will receive the value
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|  *
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|  * \return      0 if successful or a specific ASN.1 error code.
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|  */
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| int asn1_get_bool( unsigned char **p,
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|                    const unsigned char *end,
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|                    int *val );
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| 
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| /**
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|  * \brief       Retrieve an integer ASN.1 tag and its value.
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|  *              Updates the pointer to immediately behind the full tag.
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|  *
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|  * \param p     The position in the ASN.1 data
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|  * \param end   End of data
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|  * \param val   The variable that will receive the value
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|  *
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|  * \return      0 if successful or a specific ASN.1 error code.
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|  */
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| int asn1_get_int( unsigned char **p,
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|                   const unsigned char *end,
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|                   int *val );
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| 
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| /**
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|  * \brief       Retrieve a bitstring ASN.1 tag and its value.
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|  *              Updates the pointer to immediately behind the full tag.
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|  *
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|  * \param p     The position in the ASN.1 data
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|  * \param end   End of data
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|  * \param bs    The variable that will receive the value
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|  *
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|  * \return      0 if successful or a specific ASN.1 error code.
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|  */
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| int asn1_get_bitstring( unsigned char **p, const unsigned char *end,
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|                         asn1_bitstring *bs);
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| 
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| /**
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|  * \brief       Retrieve a bitstring ASN.1 tag without unused bits and its
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|  *              value.
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|  *              Updates the pointer to the beginning of the bit/octet string.
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|  *
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|  * \param p     The position in the ASN.1 data
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|  * \param end   End of data
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|  * \param len   Length of the actual bit/octect string in bytes
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|  *
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|  * \return      0 if successful or a specific ASN.1 error code.
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|  */
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| int asn1_get_bitstring_null( unsigned char **p, const unsigned char *end,
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|                              size_t *len );
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| 
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| /**
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|  * \brief       Parses and splits an ASN.1 "SEQUENCE OF <tag>"
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|  *              Updated the pointer to immediately behind the full sequence tag.
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|  *
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|  * \param p     The position in the ASN.1 data
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|  * \param end   End of data
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|  * \param cur   First variable in the chain to fill
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|  * \param tag   Type of sequence
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|  *
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|  * \return      0 if successful or a specific ASN.1 error code.
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|  */
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| int asn1_get_sequence_of( unsigned char **p,
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|                           const unsigned char *end,
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|                           asn1_sequence *cur,
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|                           int tag);
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| 
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| #if defined(POLARSSL_BIGNUM_C)
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| /**
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|  * \brief       Retrieve a MPI value from an integer ASN.1 tag.
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|  *              Updates the pointer to immediately behind the full tag.
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|  *
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|  * \param p     The position in the ASN.1 data
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|  * \param end   End of data
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|  * \param X     The MPI that will receive the value
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|  *
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|  * \return      0 if successful or a specific ASN.1 or MPI error code.
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|  */
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| int asn1_get_mpi( unsigned char **p,
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|                   const unsigned char *end,
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|                   mpi *X );
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| #endif /* POLARSSL_BIGNUM_C */
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| 
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| /**
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|  * \brief       Retrieve an AlgorithmIdentifier ASN.1 sequence.
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|  *              Updates the pointer to immediately behind the full
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|  *              AlgorithmIdentifier.
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|  *
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|  * \param p     The position in the ASN.1 data
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|  * \param end   End of data
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|  * \param alg   The buffer to receive the OID
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|  * \param params The buffer to receive the params (if any)
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|  *
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|  * \return      0 if successful or a specific ASN.1 or MPI error code.
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|  */
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| int asn1_get_alg( unsigned char **p,
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|                   const unsigned char *end,
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|                   asn1_buf *alg, asn1_buf *params );
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| 
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| /**
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|  * \brief       Retrieve an AlgorithmIdentifier ASN.1 sequence with NULL or no
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|  *              params.
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|  *              Updates the pointer to immediately behind the full
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|  *              AlgorithmIdentifier.
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|  *
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|  * \param p     The position in the ASN.1 data
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|  * \param end   End of data
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|  * \param alg   The buffer to receive the OID
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|  *
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|  * \return      0 if successful or a specific ASN.1 or MPI error code.
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|  */
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| int asn1_get_alg_null( unsigned char **p,
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|                        const unsigned char *end,
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|                        asn1_buf *alg );
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| 
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| /**
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|  * \brief       Find a specific named_data entry in a sequence or list based on
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|  *              the OID.
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|  *
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|  * \param list  The list to seek through
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|  * \param oid   The OID to look for
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|  * \param len   Size of the OID
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|  *
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|  * \return      NULL if not found, or a pointer to the existing entry.
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|  */
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| asn1_named_data *asn1_find_named_data( asn1_named_data *list,
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|                                        const char *oid, size_t len );
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| 
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| /**
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|  * \brief       Free a asn1_named_data entry
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|  *
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|  * \param entry The named data entry to free
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|  */
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| void asn1_free_named_data( asn1_named_data *entry );
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| 
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| /**
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|  * \brief       Free all entries in a asn1_named_data list
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|  *              Head will be set to NULL
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|  *
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|  * \param head  Pointer to the head of the list of named data entries to free
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|  */
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| void asn1_free_named_data_list( asn1_named_data **head );
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| 
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| #ifdef __cplusplus
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| }
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| #endif
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| 
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| #endif /* asn1.h */
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