--- /dev/null
+/**
+ * \file asn1.h
+ *
+ * \brief Generic ASN.1 parsing
+ */
+/*
+ * Copyright (C) 2006-2015, ARM Limited, All Rights Reserved
+ * SPDX-License-Identifier: GPL-2.0
+ *
+ * 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.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * This file is part of mbed TLS (https://tls.mbed.org)
+ */
+#ifndef MBEDTLS_ASN1_H
+#define MBEDTLS_ASN1_H
+
+#if !defined(MBEDTLS_CONFIG_FILE)
+#include "config.h"
+#else
+#include MBEDTLS_CONFIG_FILE
+#endif
+
+#include <stddef.h>
+
+#if defined(MBEDTLS_BIGNUM_C)
+#include "bignum.h"
+#endif
+
+/**
+ * \addtogroup asn1_module
+ * \{
+ */
+
+/**
+ * \name ASN1 Error codes
+ * These error codes are OR'ed to X509 error codes for
+ * higher error granularity.
+ * ASN1 is a standard to specify data structures.
+ * \{
+ */
+#define MBEDTLS_ERR_ASN1_OUT_OF_DATA -0x0060 /**< Out of data when parsing an ASN1 data structure. */
+#define MBEDTLS_ERR_ASN1_UNEXPECTED_TAG -0x0062 /**< ASN1 tag was of an unexpected value. */
+#define MBEDTLS_ERR_ASN1_INVALID_LENGTH -0x0064 /**< Error when trying to determine the length or invalid length. */
+#define MBEDTLS_ERR_ASN1_LENGTH_MISMATCH -0x0066 /**< Actual length differs from expected length. */
+#define MBEDTLS_ERR_ASN1_INVALID_DATA -0x0068 /**< Data is invalid. (not used) */
+#define MBEDTLS_ERR_ASN1_ALLOC_FAILED -0x006A /**< Memory allocation failed */
+#define MBEDTLS_ERR_ASN1_BUF_TOO_SMALL -0x006C /**< Buffer too small when writing ASN.1 data structure. */
+
+/* \} name */
+
+/**
+ * \name DER constants
+ * These constants comply with the DER encoded ASN.1 type tags.
+ * DER encoding uses hexadecimal representation.
+ * An example DER sequence is:\n
+ * - 0x02 -- tag indicating INTEGER
+ * - 0x01 -- length in octets
+ * - 0x05 -- value
+ * Such sequences are typically read into \c ::mbedtls_x509_buf.
+ * \{
+ */
+#define MBEDTLS_ASN1_BOOLEAN 0x01
+#define MBEDTLS_ASN1_INTEGER 0x02
+#define MBEDTLS_ASN1_BIT_STRING 0x03
+#define MBEDTLS_ASN1_OCTET_STRING 0x04
+#define MBEDTLS_ASN1_NULL 0x05
+#define MBEDTLS_ASN1_OID 0x06
+#define MBEDTLS_ASN1_UTF8_STRING 0x0C
+#define MBEDTLS_ASN1_SEQUENCE 0x10
+#define MBEDTLS_ASN1_SET 0x11
+#define MBEDTLS_ASN1_PRINTABLE_STRING 0x13
+#define MBEDTLS_ASN1_T61_STRING 0x14
+#define MBEDTLS_ASN1_IA5_STRING 0x16
+#define MBEDTLS_ASN1_UTC_TIME 0x17
+#define MBEDTLS_ASN1_GENERALIZED_TIME 0x18
+#define MBEDTLS_ASN1_UNIVERSAL_STRING 0x1C
+#define MBEDTLS_ASN1_BMP_STRING 0x1E
+#define MBEDTLS_ASN1_PRIMITIVE 0x00
+#define MBEDTLS_ASN1_CONSTRUCTED 0x20
+#define MBEDTLS_ASN1_CONTEXT_SPECIFIC 0x80
+
+/*
+ * Bit masks for each of the components of an ASN.1 tag as specified in
+ * ITU X.690 (08/2015), section 8.1 "General rules for encoding",
+ * paragraph 8.1.2.2:
+ *
+ * Bit 8 7 6 5 1
+ * +-------+-----+------------+
+ * | Class | P/C | Tag number |
+ * +-------+-----+------------+
+ */
+#define MBEDTLS_ASN1_TAG_CLASS_MASK 0xC0
+#define MBEDTLS_ASN1_TAG_PC_MASK 0x20
+#define MBEDTLS_ASN1_TAG_VALUE_MASK 0x1F
+
+/* \} name */
+/* \} addtogroup asn1_module */
+
+/** Returns the size of the binary string, without the trailing \\0 */
+#define MBEDTLS_OID_SIZE(x) (sizeof(x) - 1)
+
+/**
+ * Compares an mbedtls_asn1_buf structure to a reference OID.
+ *
+ * Only works for 'defined' oid_str values (MBEDTLS_OID_HMAC_SHA1), you cannot use a
+ * 'unsigned char *oid' here!
+ */
+#define MBEDTLS_OID_CMP(oid_str, oid_buf) \
+ ( ( MBEDTLS_OID_SIZE(oid_str) != (oid_buf)->len ) || \
+ memcmp( (oid_str), (oid_buf)->p, (oid_buf)->len) != 0 )
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/**
+ * \name Functions to parse ASN.1 data structures
+ * \{
+ */
+
+/**
+ * Type-length-value structure that allows for ASN1 using DER.
+ */
+typedef struct mbedtls_asn1_buf
+{
+ int tag; /**< ASN1 type, e.g. MBEDTLS_ASN1_UTF8_STRING. */
+ size_t len; /**< ASN1 length, in octets. */
+ unsigned char *p; /**< ASN1 data, e.g. in ASCII. */
+}
+mbedtls_asn1_buf;
+
+/**
+ * Container for ASN1 bit strings.
+ */
+typedef struct mbedtls_asn1_bitstring
+{
+ size_t len; /**< ASN1 length, in octets. */
+ unsigned char unused_bits; /**< Number of unused bits at the end of the string */
+ unsigned char *p; /**< Raw ASN1 data for the bit string */
+}
+mbedtls_asn1_bitstring;
+
+/**
+ * Container for a sequence of ASN.1 items
+ */
+typedef struct mbedtls_asn1_sequence
+{
+ mbedtls_asn1_buf buf; /**< Buffer containing the given ASN.1 item. */
+ struct mbedtls_asn1_sequence *next; /**< The next entry in the sequence. */
+}
+mbedtls_asn1_sequence;
+
+/**
+ * Container for a sequence or list of 'named' ASN.1 data items
+ */
+typedef struct mbedtls_asn1_named_data
+{
+ mbedtls_asn1_buf oid; /**< The object identifier. */
+ mbedtls_asn1_buf val; /**< The named value. */
+ struct mbedtls_asn1_named_data *next; /**< The next entry in the sequence. */
+ unsigned char next_merged; /**< Merge next item into the current one? */
+}
+mbedtls_asn1_named_data;
+
+/**
+ * \brief Get the length of an ASN.1 element.
+ * Updates the pointer to immediately behind the length.
+ *
+ * \param p The position in the ASN.1 data
+ * \param end End of data
+ * \param len The variable that will receive the value
+ *
+ * \return 0 if successful, MBEDTLS_ERR_ASN1_OUT_OF_DATA on reaching
+ * end of data, MBEDTLS_ERR_ASN1_INVALID_LENGTH if length is
+ * unparseable.
+ */
+int mbedtls_asn1_get_len( unsigned char **p,
+ const unsigned char *end,
+ size_t *len );
+
+/**
+ * \brief Get the tag and length of the tag. Check for the requested tag.
+ * Updates the pointer to immediately behind the tag and length.
+ *
+ * \param p The position in the ASN.1 data
+ * \param end End of data
+ * \param len The variable that will receive the length
+ * \param tag The expected tag
+ *
+ * \return 0 if successful, MBEDTLS_ERR_ASN1_UNEXPECTED_TAG if tag did
+ * not match requested tag, or another specific ASN.1 error code.
+ */
+int mbedtls_asn1_get_tag( unsigned char **p,
+ const unsigned char *end,
+ size_t *len, int tag );
+
+/**
+ * \brief Retrieve a boolean ASN.1 tag and its value.
+ * Updates the pointer to immediately behind the full tag.
+ *
+ * \param p The position in the ASN.1 data
+ * \param end End of data
+ * \param val The variable that will receive the value
+ *
+ * \return 0 if successful or a specific ASN.1 error code.
+ */
+int mbedtls_asn1_get_bool( unsigned char **p,
+ const unsigned char *end,
+ int *val );
+
+/**
+ * \brief Retrieve an integer ASN.1 tag and its value.
+ * Updates the pointer to immediately behind the full tag.
+ *
+ * \param p The position in the ASN.1 data
+ * \param end End of data
+ * \param val The variable that will receive the value
+ *
+ * \return 0 if successful or a specific ASN.1 error code.
+ */
+int mbedtls_asn1_get_int( unsigned char **p,
+ const unsigned char *end,
+ int *val );
+
+/**
+ * \brief Retrieve a bitstring ASN.1 tag and its value.
+ * Updates the pointer to immediately behind the full tag.
+ *
+ * \param p The position in the ASN.1 data
+ * \param end End of data
+ * \param bs The variable that will receive the value
+ *
+ * \return 0 if successful or a specific ASN.1 error code.
+ */
+int mbedtls_asn1_get_bitstring( unsigned char **p, const unsigned char *end,
+ mbedtls_asn1_bitstring *bs);
+
+/**
+ * \brief Retrieve a bitstring ASN.1 tag without unused bits and its
+ * value.
+ * Updates the pointer to the beginning of the bit/octet string.
+ *
+ * \param p The position in the ASN.1 data
+ * \param end End of data
+ * \param len Length of the actual bit/octect string in bytes
+ *
+ * \return 0 if successful or a specific ASN.1 error code.
+ */
+int mbedtls_asn1_get_bitstring_null( unsigned char **p, const unsigned char *end,
+ size_t *len );
+
+/**
+ * \brief Parses and splits an ASN.1 "SEQUENCE OF <tag>"
+ * Updated the pointer to immediately behind the full sequence tag.
+ *
+ * \param p The position in the ASN.1 data
+ * \param end End of data
+ * \param cur First variable in the chain to fill
+ * \param tag Type of sequence
+ *
+ * \return 0 if successful or a specific ASN.1 error code.
+ */
+int mbedtls_asn1_get_sequence_of( unsigned char **p,
+ const unsigned char *end,
+ mbedtls_asn1_sequence *cur,
+ int tag);
+
+#if defined(MBEDTLS_BIGNUM_C)
+/**
+ * \brief Retrieve a MPI value from an integer ASN.1 tag.
+ * Updates the pointer to immediately behind the full tag.
+ *
+ * \param p The position in the ASN.1 data
+ * \param end End of data
+ * \param X The MPI that will receive the value
+ *
+ * \return 0 if successful or a specific ASN.1 or MPI error code.
+ */
+int mbedtls_asn1_get_mpi( unsigned char **p,
+ const unsigned char *end,
+ mbedtls_mpi *X );
+#endif /* MBEDTLS_BIGNUM_C */
+
+/**
+ * \brief Retrieve an AlgorithmIdentifier ASN.1 sequence.
+ * Updates the pointer to immediately behind the full
+ * AlgorithmIdentifier.
+ *
+ * \param p The position in the ASN.1 data
+ * \param end End of data
+ * \param alg The buffer to receive the OID
+ * \param params The buffer to receive the params (if any)
+ *
+ * \return 0 if successful or a specific ASN.1 or MPI error code.
+ */
+int mbedtls_asn1_get_alg( unsigned char **p,
+ const unsigned char *end,
+ mbedtls_asn1_buf *alg, mbedtls_asn1_buf *params );
+
+/**
+ * \brief Retrieve an AlgorithmIdentifier ASN.1 sequence with NULL or no
+ * params.
+ * Updates the pointer to immediately behind the full
+ * AlgorithmIdentifier.
+ *
+ * \param p The position in the ASN.1 data
+ * \param end End of data
+ * \param alg The buffer to receive the OID
+ *
+ * \return 0 if successful or a specific ASN.1 or MPI error code.
+ */
+int mbedtls_asn1_get_alg_null( unsigned char **p,
+ const unsigned char *end,
+ mbedtls_asn1_buf *alg );
+
+/**
+ * \brief Find a specific named_data entry in a sequence or list based on
+ * the OID.
+ *
+ * \param list The list to seek through
+ * \param oid The OID to look for
+ * \param len Size of the OID
+ *
+ * \return NULL if not found, or a pointer to the existing entry.
+ */
+mbedtls_asn1_named_data *mbedtls_asn1_find_named_data( mbedtls_asn1_named_data *list,
+ const char *oid, size_t len );
+
+/**
+ * \brief Free a mbedtls_asn1_named_data entry
+ *
+ * \param entry The named data entry to free
+ */
+void mbedtls_asn1_free_named_data( mbedtls_asn1_named_data *entry );
+
+/**
+ * \brief Free all entries in a mbedtls_asn1_named_data list
+ * Head will be set to NULL
+ *
+ * \param head Pointer to the head of the list of named data entries to free
+ */
+void mbedtls_asn1_free_named_data_list( mbedtls_asn1_named_data **head );
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* asn1.h */
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