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Diffstat (limited to 'lib/mbedtls-2.27.0/include/mbedtls/asn1.h')
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diff --git a/lib/mbedtls-2.27.0/include/mbedtls/asn1.h b/lib/mbedtls-2.27.0/include/mbedtls/asn1.h new file mode 100644 index 0000000..6b79196 --- /dev/null +++ b/lib/mbedtls-2.27.0/include/mbedtls/asn1.h @@ -0,0 +1,607 @@ +/** + * \file asn1.h + * + * \brief Generic ASN.1 parsing + */ +/* + * Copyright The Mbed TLS Contributors + * SPDX-License-Identifier: Apache-2.0 + * + * Licensed under the Apache License, Version 2.0 (the "License"); you may + * not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT + * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ +#ifndef MBEDTLS_ASN1_H +#define MBEDTLS_ASN1_H + +#if !defined(MBEDTLS_CONFIG_FILE) +#include "mbedtls/config.h" +#else +#include MBEDTLS_CONFIG_FILE +#endif + +#include <stddef.h> + +#if defined(MBEDTLS_BIGNUM_C) +#include "mbedtls/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. */ +#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_ENUMERATED 0x0A +#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 + +/* Slightly smaller way to check if tag is a string tag + * compared to canonical implementation. */ +#define MBEDTLS_ASN1_IS_STRING_TAG( tag ) \ + ( ( tag ) < 32u && ( \ + ( ( 1u << ( tag ) ) & ( ( 1u << MBEDTLS_ASN1_BMP_STRING ) | \ + ( 1u << MBEDTLS_ASN1_UTF8_STRING ) | \ + ( 1u << MBEDTLS_ASN1_T61_STRING ) | \ + ( 1u << MBEDTLS_ASN1_IA5_STRING ) | \ + ( 1u << MBEDTLS_ASN1_UNIVERSAL_STRING ) | \ + ( 1u << MBEDTLS_ASN1_PRINTABLE_STRING ) | \ + ( 1u << MBEDTLS_ASN1_BIT_STRING ) ) ) != 0 ) ) + +/* + * 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 ) + +#define MBEDTLS_OID_CMP_RAW(oid_str, oid_buf, oid_buf_len) \ + ( ( MBEDTLS_OID_SIZE(oid_str) != (oid_buf_len) ) || \ + memcmp( (oid_str), (oid_buf), (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 On entry, \c *p points to the first byte of the length, + * i.e. immediately after the tag. + * On successful completion, \c *p points to the first byte + * after the length, i.e. the first byte of the content. + * On error, the value of \c *p is undefined. + * \param end End of data. + * \param len On successful completion, \c *len contains the length + * read from the ASN.1 input. + * + * \return 0 if successful. + * \return #MBEDTLS_ERR_ASN1_OUT_OF_DATA if the ASN.1 element + * would end beyond \p end. + * \return #MBEDTLS_ERR_ASN1_INVALID_LENGTH if the 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 element. + * Check for the requested tag. + * Updates the pointer to immediately behind the tag and length. + * + * \param p On entry, \c *p points to the start of the ASN.1 element. + * On successful completion, \c *p points to the first byte + * after the length, i.e. the first byte of the content. + * On error, the value of \c *p is undefined. + * \param end End of data. + * \param len On successful completion, \c *len contains the length + * read from the ASN.1 input. + * \param tag The expected tag. + * + * \return 0 if successful. + * \return #MBEDTLS_ERR_ASN1_UNEXPECTED_TAG if the data does not start + * with the requested tag. + * \return #MBEDTLS_ERR_ASN1_OUT_OF_DATA if the ASN.1 element + * would end beyond \p end. + * \return #MBEDTLS_ERR_ASN1_INVALID_LENGTH if the length is unparseable. + */ +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 On entry, \c *p points to the start of the ASN.1 element. + * On successful completion, \c *p points to the first byte + * beyond the ASN.1 element. + * On error, the value of \c *p is undefined. + * \param end End of data. + * \param val On success, the parsed value (\c 0 or \c 1). + * + * \return 0 if successful. + * \return An ASN.1 error code if the input does not start with + * a valid ASN.1 BOOLEAN. + */ +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 On entry, \c *p points to the start of the ASN.1 element. + * On successful completion, \c *p points to the first byte + * beyond the ASN.1 element. + * On error, the value of \c *p is undefined. + * \param end End of data. + * \param val On success, the parsed value. + * + * \return 0 if successful. + * \return An ASN.1 error code if the input does not start with + * a valid ASN.1 INTEGER. + * \return #MBEDTLS_ERR_ASN1_INVALID_LENGTH if the parsed value does + * not fit in an \c int. + */ +int mbedtls_asn1_get_int( unsigned char **p, + const unsigned char *end, + int *val ); + +/** + * \brief Retrieve an enumerated ASN.1 tag and its value. + * Updates the pointer to immediately behind the full tag. + * + * \param p On entry, \c *p points to the start of the ASN.1 element. + * On successful completion, \c *p points to the first byte + * beyond the ASN.1 element. + * On error, the value of \c *p is undefined. + * \param end End of data. + * \param val On success, the parsed value. + * + * \return 0 if successful. + * \return An ASN.1 error code if the input does not start with + * a valid ASN.1 ENUMERATED. + * \return #MBEDTLS_ERR_ASN1_INVALID_LENGTH if the parsed value does + * not fit in an \c int. + */ +int mbedtls_asn1_get_enum( 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 On entry, \c *p points to the start of the ASN.1 element. + * On successful completion, \c *p is equal to \p end. + * On error, the value of \c *p is undefined. + * \param end End of data. + * \param bs On success, ::mbedtls_asn1_bitstring information about + * the parsed value. + * + * \return 0 if successful. + * \return #MBEDTLS_ERR_ASN1_LENGTH_MISMATCH if the input contains + * extra data after a valid BIT STRING. + * \return An ASN.1 error code if the input does not start with + * a valid ASN.1 BIT STRING. + */ +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 On entry, \c *p points to the start of the ASN.1 element. + * On successful completion, \c *p points to the first byte + * of the content of the BIT STRING. + * On error, the value of \c *p is undefined. + * \param end End of data. + * \param len On success, \c *len is the length of the content in bytes. + * + * \return 0 if successful. + * \return #MBEDTLS_ERR_ASN1_INVALID_DATA if the input starts with + * a valid BIT STRING with a nonzero number of unused bits. + * \return An ASN.1 error code if the input does not start with + * a valid ASN.1 BIT STRING. + */ +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>". + * Updates the pointer to immediately behind the full sequence tag. + * + * This function allocates memory for the sequence elements. You can free + * the allocated memory with mbedtls_asn1_sequence_free(). + * + * \note On error, this function may return a partial list in \p cur. + * You must set `cur->next = NULL` before calling this function! + * Otherwise it is impossible to distinguish a previously non-null + * pointer from a pointer to an object allocated by this function. + * + * \note If the sequence is empty, this function does not modify + * \c *cur. If the sequence is valid and non-empty, this + * function sets `cur->buf.tag` to \p tag. This allows + * callers to distinguish between an empty sequence and + * a one-element sequence. + * + * \param p On entry, \c *p points to the start of the ASN.1 element. + * On successful completion, \c *p is equal to \p end. + * On error, the value of \c *p is undefined. + * \param end End of data. + * \param cur A ::mbedtls_asn1_sequence which this function fills. + * When this function returns, \c *cur is the head of a linked + * list. Each node in this list is allocated with + * mbedtls_calloc() apart from \p cur itself, and should + * therefore be freed with mbedtls_free(). + * The list describes the content of the sequence. + * The head of the list (i.e. \c *cur itself) describes the + * first element, `*cur->next` describes the second element, etc. + * For each element, `buf.tag == tag`, `buf.len` is the length + * of the content of the content of the element, and `buf.p` + * points to the first byte of the content (i.e. immediately + * past the length of the element). + * Note that list elements may be allocated even on error. + * \param tag Each element of the sequence must have this tag. + * + * \return 0 if successful. + * \return #MBEDTLS_ERR_ASN1_LENGTH_MISMATCH if the input contains + * extra data after a valid SEQUENCE OF \p tag. + * \return #MBEDTLS_ERR_ASN1_UNEXPECTED_TAG if the input starts with + * an ASN.1 SEQUENCE in which an element has a tag that + * is different from \p tag. + * \return #MBEDTLS_ERR_ASN1_ALLOC_FAILED if a memory allocation failed. + * \return An ASN.1 error code if the input does not start with + * a valid ASN.1 SEQUENCE. + */ +int mbedtls_asn1_get_sequence_of( unsigned char **p, + const unsigned char *end, + mbedtls_asn1_sequence *cur, + int tag ); +/** + * \brief Free a heap-allocated linked list presentation of + * an ASN.1 sequence, including the first element. + * + * There are two common ways to manage the memory used for the representation + * of a parsed ASN.1 sequence: + * - Allocate a head node `mbedtls_asn1_sequence *head` with mbedtls_calloc(). + * Pass this node as the `cur` argument to mbedtls_asn1_get_sequence_of(). + * When you have finished processing the sequence, + * call mbedtls_asn1_sequence_free() on `head`. + * - Allocate a head node `mbedtls_asn1_sequence *head` in any manner, + * for example on the stack. Make sure that `head->next == NULL`. + * Pass `head` as the `cur` argument to mbedtls_asn1_get_sequence_of(). + * When you have finished processing the sequence, + * call mbedtls_asn1_sequence_free() on `head->cur`, + * then free `head` itself in the appropriate manner. + * + * \param seq The address of the first sequence component. This may + * be \c NULL, in which case this functions returns + * immediately. + */ +void mbedtls_asn1_sequence_free( mbedtls_asn1_sequence *seq ); + +/** + * \brief Traverse an ASN.1 SEQUENCE container and + * call a callback for each entry. + * + * This function checks that the input is a SEQUENCE of elements that + * each have a "must" tag, and calls a callback function on the elements + * that have a "may" tag. + * + * For example, to validate that the input is a SEQUENCE of `tag1` and call + * `cb` on each element, use + * ``` + * mbedtls_asn1_traverse_sequence_of(&p, end, 0xff, tag1, 0, 0, cb, ctx); + * ``` + * + * To validate that the input is a SEQUENCE of ANY and call `cb` on + * each element, use + * ``` + * mbedtls_asn1_traverse_sequence_of(&p, end, 0, 0, 0, 0, cb, ctx); + * ``` + * + * To validate that the input is a SEQUENCE of CHOICE {NULL, OCTET STRING} + * and call `cb` on each element that is an OCTET STRING, use + * ``` + * mbedtls_asn1_traverse_sequence_of(&p, end, 0xfe, 0x04, 0xff, 0x04, cb, ctx); + * ``` + * + * The callback is called on the elements with a "may" tag from left to + * right. If the input is not a valid SEQUENCE of elements with a "must" tag, + * the callback is called on the elements up to the leftmost point where + * the input is invalid. + * + * \warning This function is still experimental and may change + * at any time. + * + * \param p The address of the pointer to the beginning of + * the ASN.1 SEQUENCE header. This is updated to + * point to the end of the ASN.1 SEQUENCE container + * on a successful invocation. + * \param end The end of the ASN.1 SEQUENCE container. + * \param tag_must_mask A mask to be applied to the ASN.1 tags found within + * the SEQUENCE before comparing to \p tag_must_value. + * \param tag_must_val The required value of each ASN.1 tag found in the + * SEQUENCE, after masking with \p tag_must_mask. + * Mismatching tags lead to an error. + * For example, a value of \c 0 for both \p tag_must_mask + * and \p tag_must_val means that every tag is allowed, + * while a value of \c 0xFF for \p tag_must_mask means + * that \p tag_must_val is the only allowed tag. + * \param tag_may_mask A mask to be applied to the ASN.1 tags found within + * the SEQUENCE before comparing to \p tag_may_value. + * \param tag_may_val The desired value of each ASN.1 tag found in the + * SEQUENCE, after masking with \p tag_may_mask. + * Mismatching tags will be silently ignored. + * For example, a value of \c 0 for \p tag_may_mask and + * \p tag_may_val means that any tag will be considered, + * while a value of \c 0xFF for \p tag_may_mask means + * that all tags with value different from \p tag_may_val + * will be ignored. + * \param cb The callback to trigger for each component + * in the ASN.1 SEQUENCE that matches \p tag_may_val. + * The callback function is called with the following + * parameters: + * - \p ctx. + * - The tag of the current element. + * - A pointer to the start of the current element's + * content inside the input. + * - The length of the content of the current element. + * If the callback returns a non-zero value, + * the function stops immediately, + * forwarding the callback's return value. + * \param ctx The context to be passed to the callback \p cb. + * + * \return \c 0 if successful the entire ASN.1 SEQUENCE + * was traversed without parsing or callback errors. + * \return #MBEDTLS_ERR_ASN1_LENGTH_MISMATCH if the input + * contains extra data after a valid SEQUENCE + * of elements with an accepted tag. + * \return #MBEDTLS_ERR_ASN1_UNEXPECTED_TAG if the input starts + * with an ASN.1 SEQUENCE in which an element has a tag + * that is not accepted. + * \return An ASN.1 error code if the input does not start with + * a valid ASN.1 SEQUENCE. + * \return A non-zero error code forwarded from the callback + * \p cb in case the latter returns a non-zero value. + */ +int mbedtls_asn1_traverse_sequence_of( + unsigned char **p, + const unsigned char *end, + unsigned char tag_must_mask, unsigned char tag_must_val, + unsigned char tag_may_mask, unsigned char tag_may_val, + int (*cb)( void *ctx, int tag, + unsigned char* start, size_t len ), + void *ctx ); + +#if defined(MBEDTLS_BIGNUM_C) +/** + * \brief Retrieve an integer ASN.1 tag and its value. + * Updates the pointer to immediately behind the full tag. + * + * \param p On entry, \c *p points to the start of the ASN.1 element. + * On successful completion, \c *p points to the first byte + * beyond the ASN.1 element. + * On error, the value of \c *p is undefined. + * \param end End of data. + * \param X On success, the parsed value. + * + * \return 0 if successful. + * \return An ASN.1 error code if the input does not start with + * a valid ASN.1 INTEGER. + * \return #MBEDTLS_ERR_ASN1_INVALID_LENGTH if the parsed value does + * not fit in an \c int. + * \return An MPI error code if the parsed value is too large. + */ +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 On entry, \c *p points to the start of the ASN.1 element. + * On successful completion, \c *p points to the first byte + * beyond the AlgorithmIdentifier element. + * On error, the value of \c *p is undefined. + * \param end End of data. + * \param alg The buffer to receive the OID. + * \param params The buffer to receive the parameters. + * This is zeroized if there are no parameters. + * + * \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 On entry, \c *p points to the start of the ASN.1 element. + * On successful completion, \c *p points to the first byte + * beyond the AlgorithmIdentifier element. + * On error, the value of \c *p is undefined. + * \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. + * This function calls mbedtls_free() on + * `entry->oid.p` and `entry->val.p`. + */ +void mbedtls_asn1_free_named_data( mbedtls_asn1_named_data *entry ); + +/** + * \brief Free all entries in a mbedtls_asn1_named_data list. + * + * \param head Pointer to the head of the list of named data entries to free. + * This function calls mbedtls_asn1_free_named_data() and + * mbedtls_free() on each list element and + * sets \c *head to \c NULL. + */ +void mbedtls_asn1_free_named_data_list( mbedtls_asn1_named_data **head ); + +#ifdef __cplusplus +} +#endif + +#endif /* asn1.h */ |