#ifndef _IPXE_ASN1_H
#define _IPXE_ASN1_H

/** @file
 *
 * ASN.1 encoding
 *
 */

FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );

#include <stddef.h>
#include <stdint.h>
#include <stdarg.h>
#include <assert.h>
#include <time.h>
#include <ipxe/tables.h>

/** An ASN.1 object cursor */
struct asn1_cursor {
	/** Start of data */
	const void *data;
	/** Length of data */
	size_t len;
};

/** An ASN.1 object builder */
struct asn1_builder {
	/** Data
	 *
	 * This is always dynamically allocated.  If @c data is NULL
	 * while @len is non-zero, this indicates that a memory
	 * allocation error has occurred during the building process.
	 */
	void *data;
	/** Length of data */
	size_t len;
};

/** Maximum (viable) length of ASN.1 length
 *
 * While in theory unlimited, this length is sufficient to contain a
 * size_t.
 */
#define ASN1_MAX_LEN_LEN ( 1 + sizeof ( size_t ) )

/** An ASN.1 header */
struct asn1_builder_header {
	/** Type */
	uint8_t type;
	/** Length (encoded) */
	uint8_t length[ASN1_MAX_LEN_LEN];
} __attribute__ (( packed ));

/** ASN.1 end */
#define ASN1_END 0x00

/** ASN.1 boolean */
#define ASN1_BOOLEAN 0x01

/** ASN.1 integer */
#define ASN1_INTEGER 0x02

/** ASN.1 bit string */
#define ASN1_BIT_STRING 0x03

/** ASN.1 octet string */
#define ASN1_OCTET_STRING 0x04

/** ASN.1 null */
#define ASN1_NULL 0x05

/** ASN.1 object identifier */
#define ASN1_OID 0x06

/** ASN.1 enumeration */
#define ASN1_ENUMERATED 0x0a

/** ASN.1 UTF-8 string */
#define ASN1_UTF8_STRING 0x0c

/** ASN.1 UTC time */
#define ASN1_UTC_TIME 0x17

/** ASN.1 generalized time */
#define ASN1_GENERALIZED_TIME 0x18

/** ASN.1 sequence */
#define ASN1_SEQUENCE 0x30

/** ASN.1 set */
#define ASN1_SET 0x31

/** ASN.1 implicit tag */
#define ASN1_IMPLICIT_TAG( number) ( 0x80 | (number) )

/** ASN.1 explicit tag */
#define ASN1_EXPLICIT_TAG( number) ( 0xa0 | (number) )

/** ASN.1 "any tag" magic value */
#define ASN1_ANY -1U

/** Construct a short ASN.1 value */
#define ASN1_SHORT( tag, ... ) \
	(tag), VA_ARG_COUNT ( __VA_ARGS__ ), __VA_ARGS__

/** Initial OID byte */
#define ASN1_OID_INITIAL( first, second ) ( ( (first) * 40 ) + (second) )

/** Single-byte OID value
 *
 * Valid for values up to 127
 */
#define ASN1_OID_SINGLE( value ) ( (value) & 0x7f )

/** Double-byte OID value
 *
 * Valid for values up to 16383
 */
#define ASN1_OID_DOUBLE( value ) \
	( 0x80 | ( ( (value) >> 7 ) & 0x7f ) ), ASN1_OID_SINGLE ( (value) )

/** Double-byte OID value
 *
 * Valid for values up to 2097151
 */
#define ASN1_OID_TRIPLE( value ) \
	( 0x80 | ( ( (value) >> 14 ) & 0x7f ) ), ASN1_OID_DOUBLE ( (value) )

/** ASN.1 OID for prime256v1 (1.2.840.10045.3.1.7) */
#define ASN1_OID_PRIME256V1					\
	ASN1_OID_INITIAL ( 1, 1 ), ASN1_OID_DOUBLE ( 840 ),	\
	ASN1_OID_DOUBLE ( 10045 ), ASN1_OID_SINGLE ( 3 ),	\
	ASN1_OID_SINGLE ( 1 ), ASN1_OID_SINGLE ( 7 )

/** ASN.1 OID for rsaEncryption (1.2.840.113549.1.1.1) */
#define ASN1_OID_RSAENCRYPTION					\
	ASN1_OID_INITIAL ( 1, 2 ), ASN1_OID_DOUBLE ( 840 ),	\
	ASN1_OID_TRIPLE ( 113549 ), ASN1_OID_SINGLE ( 1 ),	\
	ASN1_OID_SINGLE ( 1 ), ASN1_OID_SINGLE ( 1 )

/** ASN.1 OID for md5WithRSAEncryption (1.2.840.113549.1.1.4) */
#define ASN1_OID_MD5WITHRSAENCRYPTION				\
	ASN1_OID_INITIAL ( 1, 2 ), ASN1_OID_DOUBLE ( 840 ),	\
	ASN1_OID_TRIPLE ( 113549 ), ASN1_OID_SINGLE ( 1 ),	\
	ASN1_OID_SINGLE ( 1 ), ASN1_OID_SINGLE ( 4 )

/** ASN.1 OID for sha1WithRSAEncryption (1.2.840.113549.1.1.5) */
#define ASN1_OID_SHA1WITHRSAENCRYPTION				\
	ASN1_OID_INITIAL ( 1, 2 ), ASN1_OID_DOUBLE ( 840 ),	\
	ASN1_OID_TRIPLE ( 113549 ), ASN1_OID_SINGLE ( 1 ),	\
	ASN1_OID_SINGLE ( 1 ), ASN1_OID_SINGLE ( 5 )

/** ASN.1 OID for sha256WithRSAEncryption (1.2.840.113549.1.1.11) */
#define ASN1_OID_SHA256WITHRSAENCRYPTION			\
	ASN1_OID_INITIAL ( 1, 2 ), ASN1_OID_DOUBLE ( 840 ),	\
	ASN1_OID_TRIPLE ( 113549 ), ASN1_OID_SINGLE ( 1 ),	\
	ASN1_OID_SINGLE ( 1 ), ASN1_OID_SINGLE ( 11 )

/** ASN.1 OID for sha384WithRSAEncryption (1.2.840.113549.1.1.12) */
#define ASN1_OID_SHA384WITHRSAENCRYPTION			\
	ASN1_OID_INITIAL ( 1, 2 ), ASN1_OID_DOUBLE ( 840 ),	\
	ASN1_OID_TRIPLE ( 113549 ), ASN1_OID_SINGLE ( 1 ),	\
	ASN1_OID_SINGLE ( 1 ), ASN1_OID_SINGLE ( 12 )

/** ASN.1 OID for sha512WithRSAEncryption (1.2.840.113549.1.1.13) */
#define ASN1_OID_SHA512WITHRSAENCRYPTION			\
	ASN1_OID_INITIAL ( 1, 2 ), ASN1_OID_DOUBLE ( 840 ),	\
	ASN1_OID_TRIPLE ( 113549 ), ASN1_OID_SINGLE ( 1 ),	\
	ASN1_OID_SINGLE ( 1 ), ASN1_OID_SINGLE ( 13 )

/** ASN.1 OID for sha224WithRSAEncryption (1.2.840.113549.1.1.14) */
#define ASN1_OID_SHA224WITHRSAENCRYPTION			\
	ASN1_OID_INITIAL ( 1, 2 ), ASN1_OID_DOUBLE ( 840 ),	\
	ASN1_OID_TRIPLE ( 113549 ), ASN1_OID_SINGLE ( 1 ),	\
	ASN1_OID_SINGLE ( 1 ), ASN1_OID_SINGLE ( 14 )

/** ASN.1 OID for id-md4 (1.2.840.113549.2.4) */
#define ASN1_OID_MD4						\
	ASN1_OID_INITIAL ( 1, 2 ), ASN1_OID_DOUBLE ( 840 ),	\
	ASN1_OID_TRIPLE ( 113549 ), ASN1_OID_SINGLE ( 2 ),	\
	ASN1_OID_SINGLE ( 4 )

/** ASN.1 OID for id-md5 (1.2.840.113549.2.5) */
#define ASN1_OID_MD5						\
	ASN1_OID_INITIAL ( 1, 2 ), ASN1_OID_DOUBLE ( 840 ),	\
	ASN1_OID_TRIPLE ( 113549 ), ASN1_OID_SINGLE ( 2 ),	\
	ASN1_OID_SINGLE ( 5 )

/** ASN.1 OID for id-sha1 (1.3.14.3.2.26) */
#define ASN1_OID_SHA1						\
	ASN1_OID_INITIAL ( 1, 3 ), ASN1_OID_SINGLE ( 14 ),	\
	ASN1_OID_SINGLE ( 3 ), ASN1_OID_SINGLE ( 2 ),		\
	ASN1_OID_SINGLE ( 26 )

/** ASN.1 OID for id-x25519 (1.3.101.110) */
#define ASN1_OID_X25519						\
	ASN1_OID_INITIAL ( 1, 3 ), ASN1_OID_SINGLE ( 101 ),	\
	ASN1_OID_SINGLE ( 110 )

/** ASN.1 OID for secp384r1 (1.3.132.0.34) */
#define ASN1_OID_SECP384R1					\
	ASN1_OID_INITIAL ( 1, 3 ), ASN1_OID_DOUBLE ( 132 ),	\
	ASN1_OID_SINGLE ( 0 ), ASN1_OID_SINGLE ( 34 )

/** ASN.1 OID for id-aes128-cbc (2.16.840.1.101.3.4.1.2) */
#define ASN1_OID_AES128_CBC					\
	ASN1_OID_INITIAL ( 2, 16 ), ASN1_OID_DOUBLE ( 840 ),	\
	ASN1_OID_SINGLE ( 1 ), ASN1_OID_SINGLE ( 101 ),		\
	ASN1_OID_SINGLE ( 3 ), ASN1_OID_SINGLE ( 4 ),		\
	ASN1_OID_SINGLE ( 1 ), ASN1_OID_SINGLE ( 2 )

/** ASN.1 OID for id-aes128-gcm (2.16.840.1.101.3.4.1.6) */
#define ASN1_OID_AES128_GCM					\
	ASN1_OID_INITIAL ( 2, 16 ), ASN1_OID_DOUBLE ( 840 ),	\
	ASN1_OID_SINGLE ( 1 ), ASN1_OID_SINGLE ( 101 ),		\
	ASN1_OID_SINGLE ( 3 ), ASN1_OID_SINGLE ( 4 ),		\
	ASN1_OID_SINGLE ( 1 ), ASN1_OID_SINGLE ( 6 )

/** ASN.1 OID for id-aes192-cbc (2.16.840.1.101.3.4.1.22) */
#define ASN1_OID_AES192_CBC					\
	ASN1_OID_INITIAL ( 2, 16 ), ASN1_OID_DOUBLE ( 840 ),	\
	ASN1_OID_SINGLE ( 1 ), ASN1_OID_SINGLE ( 101 ),		\
	ASN1_OID_SINGLE ( 3 ), ASN1_OID_SINGLE ( 4 ),		\
	ASN1_OID_SINGLE ( 1 ), ASN1_OID_SINGLE ( 22 )

/** ASN.1 OID for id-aes192-gcm (2.16.840.1.101.3.4.1.26) */
#define ASN1_OID_AES192_GCM					\
	ASN1_OID_INITIAL ( 2, 16 ), ASN1_OID_DOUBLE ( 840 ),	\
	ASN1_OID_SINGLE ( 1 ), ASN1_OID_SINGLE ( 101 ),		\
	ASN1_OID_SINGLE ( 3 ), ASN1_OID_SINGLE ( 4 ),		\
	ASN1_OID_SINGLE ( 1 ), ASN1_OID_SINGLE ( 26 )

/** ASN.1 OID for id-aes256-cbc (2.16.840.1.101.3.4.1.42) */
#define ASN1_OID_AES256_CBC					\
	ASN1_OID_INITIAL ( 2, 16 ), ASN1_OID_DOUBLE ( 840 ),	\
	ASN1_OID_SINGLE ( 1 ), ASN1_OID_SINGLE ( 101 ),		\
	ASN1_OID_SINGLE ( 3 ), ASN1_OID_SINGLE ( 4 ),		\
	ASN1_OID_SINGLE ( 1 ), ASN1_OID_SINGLE ( 42 )

/** ASN.1 OID for id-aes256-gcm (2.16.840.1.101.3.4.1.46) */
#define ASN1_OID_AES256_GCM					\
	ASN1_OID_INITIAL ( 2, 16 ), ASN1_OID_DOUBLE ( 840 ),	\
	ASN1_OID_SINGLE ( 1 ), ASN1_OID_SINGLE ( 101 ),		\
	ASN1_OID_SINGLE ( 3 ), ASN1_OID_SINGLE ( 4 ),		\
	ASN1_OID_SINGLE ( 1 ), ASN1_OID_SINGLE ( 46 )

/** ASN.1 OID for id-sha256 (2.16.840.1.101.3.4.2.1) */
#define ASN1_OID_SHA256						\
	ASN1_OID_INITIAL ( 2, 16 ), ASN1_OID_DOUBLE ( 840 ),	\
	ASN1_OID_SINGLE ( 1 ), ASN1_OID_SINGLE ( 101 ),		\
	ASN1_OID_SINGLE ( 3 ), ASN1_OID_SINGLE ( 4 ),		\
	ASN1_OID_SINGLE ( 2 ), ASN1_OID_SINGLE ( 1 )

/** ASN.1 OID for id-sha384 (2.16.840.1.101.3.4.2.2) */
#define ASN1_OID_SHA384						\
	ASN1_OID_INITIAL ( 2, 16 ), ASN1_OID_DOUBLE ( 840 ),	\
	ASN1_OID_SINGLE ( 1 ), ASN1_OID_SINGLE ( 101 ),		\
	ASN1_OID_SINGLE ( 3 ), ASN1_OID_SINGLE ( 4 ),		\
	ASN1_OID_SINGLE ( 2 ), ASN1_OID_SINGLE ( 2 )

/** ASN.1 OID for id-sha512 (2.16.840.1.101.3.4.2.3) */
#define ASN1_OID_SHA512						\
	ASN1_OID_INITIAL ( 2, 16 ), ASN1_OID_DOUBLE ( 840 ),	\
	ASN1_OID_SINGLE ( 1 ), ASN1_OID_SINGLE ( 101 ),		\
	ASN1_OID_SINGLE ( 3 ), ASN1_OID_SINGLE ( 4 ),		\
	ASN1_OID_SINGLE ( 2 ), ASN1_OID_SINGLE ( 3 )

/** ASN.1 OID for id-sha224 (2.16.840.1.101.3.4.2.4) */
#define ASN1_OID_SHA224						\
	ASN1_OID_INITIAL ( 2, 16 ), ASN1_OID_DOUBLE ( 840 ),	\
	ASN1_OID_SINGLE ( 1 ), ASN1_OID_SINGLE ( 101 ),		\
	ASN1_OID_SINGLE ( 3 ), ASN1_OID_SINGLE ( 4 ),		\
	ASN1_OID_SINGLE ( 2 ), ASN1_OID_SINGLE ( 4 )

/** ASN.1 OID for id-sha512-224 (2.16.840.1.101.3.4.2.5) */
#define ASN1_OID_SHA512_224						\
	ASN1_OID_INITIAL ( 2, 16 ), ASN1_OID_DOUBLE ( 840 ),	\
	ASN1_OID_SINGLE ( 1 ), ASN1_OID_SINGLE ( 101 ),		\
	ASN1_OID_SINGLE ( 3 ), ASN1_OID_SINGLE ( 4 ),		\
	ASN1_OID_SINGLE ( 2 ), ASN1_OID_SINGLE ( 5 )

/** ASN.1 OID for id-sha512-256 (2.16.840.1.101.3.4.2.6) */
#define ASN1_OID_SHA512_256						\
	ASN1_OID_INITIAL ( 2, 16 ), ASN1_OID_DOUBLE ( 840 ),	\
	ASN1_OID_SINGLE ( 1 ), ASN1_OID_SINGLE ( 101 ),		\
	ASN1_OID_SINGLE ( 3 ), ASN1_OID_SINGLE ( 4 ),		\
	ASN1_OID_SINGLE ( 2 ), ASN1_OID_SINGLE ( 6 )

/** ASN.1 OID for commonName (2.5.4.3) */
#define ASN1_OID_COMMON_NAME					\
	ASN1_OID_INITIAL ( 2, 5 ), ASN1_OID_SINGLE ( 4 ),	\
	ASN1_OID_SINGLE ( 3 )

/** ASN.1 OID for id-ce-keyUsage (2.5.29.15) */
#define ASN1_OID_KEYUSAGE					\
	ASN1_OID_INITIAL ( 2, 5 ), ASN1_OID_SINGLE ( 29 ),	\
	ASN1_OID_SINGLE ( 15 )

/** ASN.1 OID for id-ce-basicConstraints (2.5.29.19) */
#define ASN1_OID_BASICCONSTRAINTS				\
	ASN1_OID_INITIAL ( 2, 5 ), ASN1_OID_SINGLE ( 29 ),	\
	ASN1_OID_SINGLE ( 19 )

/** ASN.1 OID for id-ce-extKeyUsage (2.5.29.37) */
#define ASN1_OID_EXTKEYUSAGE					\
	ASN1_OID_INITIAL ( 2, 5 ), ASN1_OID_SINGLE ( 29 ),	\
	ASN1_OID_SINGLE ( 37 )

/** ASN.1 OID for id-kp-codeSigning (1.3.6.1.5.5.7.3.3) */
#define ASN1_OID_CODESIGNING					\
	ASN1_OID_INITIAL ( 1, 3 ), ASN1_OID_SINGLE ( 6 ),	\
	ASN1_OID_SINGLE ( 1 ), ASN1_OID_SINGLE ( 5 ),		\
	ASN1_OID_SINGLE ( 5 ), ASN1_OID_SINGLE ( 7 ),		\
	ASN1_OID_SINGLE ( 3 ), ASN1_OID_SINGLE ( 3 )

/** ASN.1 OID for id-signedData (1.2.840.113549.1.7.2) */
#define ASN1_OID_SIGNEDDATA					\
	ASN1_OID_INITIAL ( 1, 2 ), ASN1_OID_DOUBLE ( 840 ),	\
	ASN1_OID_TRIPLE ( 113549 ), ASN1_OID_SINGLE ( 1 ),	\
	ASN1_OID_SINGLE ( 7 ), ASN1_OID_SINGLE ( 2 )

/** ASN.1 OID for id-envelopedData (1.2.840.113549.1.7.3) */
#define ASN1_OID_ENVELOPEDDATA					\
	ASN1_OID_INITIAL ( 1, 2 ), ASN1_OID_DOUBLE ( 840 ),	\
	ASN1_OID_TRIPLE ( 113549 ), ASN1_OID_SINGLE ( 1 ),	\
	ASN1_OID_SINGLE ( 7 ), ASN1_OID_SINGLE ( 3 )

/** ASN.1 OID for id-authEnvelopedData (1.2.840.113549.1.9.16.1.23) */
#define ASN1_OID_AUTHENVELOPEDDATA					\
	ASN1_OID_INITIAL ( 1, 2 ), ASN1_OID_DOUBLE ( 840 ),	\
	ASN1_OID_TRIPLE ( 113549 ), ASN1_OID_SINGLE ( 1 ),	\
	ASN1_OID_SINGLE ( 9 ), ASN1_OID_SINGLE ( 16 ),		\
	ASN1_OID_SINGLE ( 1 ), ASN1_OID_SINGLE ( 23 )

/** ASN.1 OID for id-pe-authorityInfoAccess (1.3.6.1.5.5.7.1.1) */
#define ASN1_OID_AUTHORITYINFOACCESS				\
	ASN1_OID_INITIAL ( 1, 3 ), ASN1_OID_SINGLE ( 6 ),	\
	ASN1_OID_SINGLE ( 1 ), ASN1_OID_SINGLE ( 5 ),		\
	ASN1_OID_SINGLE ( 5 ), ASN1_OID_SINGLE ( 7 ),		\
	ASN1_OID_SINGLE ( 1 ), ASN1_OID_SINGLE ( 1 )

/** ASN.1 OID for id-ad-ocsp (1.3.6.1.5.5.7.48.1) */
#define ASN1_OID_OCSP						\
	ASN1_OID_INITIAL ( 1, 3 ), ASN1_OID_SINGLE ( 6 ),	\
	ASN1_OID_SINGLE ( 1 ), ASN1_OID_SINGLE ( 5 ),		\
	ASN1_OID_SINGLE ( 5 ), ASN1_OID_SINGLE ( 7 ),		\
	ASN1_OID_SINGLE ( 48 ), ASN1_OID_SINGLE ( 1 )

/** ASN.1 OID for id-pkix-ocsp-basic ( 1.3.6.1.5.5.7.48.1.1) */
#define ASN1_OID_OCSP_BASIC					\
	ASN1_OID_INITIAL ( 1, 3 ), ASN1_OID_SINGLE ( 6 ),	\
	ASN1_OID_SINGLE ( 1 ), ASN1_OID_SINGLE ( 5 ),		\
	ASN1_OID_SINGLE ( 5 ), ASN1_OID_SINGLE ( 7 ),		\
	ASN1_OID_SINGLE ( 48 ), ASN1_OID_SINGLE ( 1 ),		\
	ASN1_OID_SINGLE ( 1 )

/** ASN.1 OID for id-kp-OCSPSigning (1.3.6.1.5.5.7.3.9) */
#define ASN1_OID_OCSPSIGNING					\
	ASN1_OID_INITIAL ( 1, 3 ), ASN1_OID_SINGLE ( 6 ),	\
	ASN1_OID_SINGLE ( 1 ), ASN1_OID_SINGLE ( 5 ),		\
	ASN1_OID_SINGLE ( 5 ), ASN1_OID_SINGLE ( 7 ),		\
	ASN1_OID_SINGLE ( 3 ), ASN1_OID_SINGLE ( 9 )

/** ASN.1 OID for id-ce-subjectAltName (2.5.29.17) */
#define ASN1_OID_SUBJECTALTNAME					\
	ASN1_OID_INITIAL ( 2, 5 ), ASN1_OID_SINGLE ( 29 ),	\
	ASN1_OID_SINGLE ( 17 )

/** Define an ASN.1 cursor for a static value */
#define ASN1_CURSOR( value ) {					\
		.data = value,					\
		.len = sizeof ( value ),			\
	}

/** An ASN.1 OID-identified algorithm */
struct asn1_algorithm {
	/** Name */
	const char *name;
	/** Object identifier */
	struct asn1_cursor oid;
	/** Public-key algorithm (if applicable) */
	struct pubkey_algorithm *pubkey;
	/** Digest algorithm (if applicable) */
	struct digest_algorithm *digest;
	/** Cipher algorithm (if applicable) */
	struct cipher_algorithm *cipher;
	/** Elliptic curve (if applicable) */
	struct elliptic_curve *curve;
	/**
	 * Parse algorithm parameters (optional)
	 *
	 * @v algorithm		Algorithm
	 * @v param		Parameters to parse (and potentially modify)
	 * @ret rc		Return status code
	 */
	int ( * parse ) ( struct asn1_algorithm *algorithm,
			  struct asn1_cursor *params );
};

/** ASN.1 OID-identified algorithms */
#define ASN1_ALGORITHMS __table ( struct asn1_algorithm, "asn1_algorithms" )

/** Declare an ASN.1 OID-identified algorithm */
#define __asn1_algorithm __table_entry ( ASN1_ALGORITHMS, 01 )

/* ASN.1 OID-identified algorithms */
extern struct asn1_algorithm rsa_encryption_algorithm __asn1_algorithm;
extern struct asn1_algorithm md5_with_rsa_encryption_algorithm __asn1_algorithm;
extern struct asn1_algorithm
sha1_with_rsa_encryption_algorithm __asn1_algorithm;
extern struct asn1_algorithm
sha256_with_rsa_encryption_algorithm __asn1_algorithm;
extern struct asn1_algorithm
sha384_with_rsa_encryption_algorithm __asn1_algorithm;
extern struct asn1_algorithm
sha512_with_rsa_encryption_algorithm __asn1_algorithm;
extern struct asn1_algorithm
sha224_with_rsa_encryption_algorithm __asn1_algorithm;
extern struct asn1_algorithm oid_md4_algorithm __asn1_algorithm;
extern struct asn1_algorithm oid_md5_algorithm __asn1_algorithm;
extern struct asn1_algorithm oid_sha1_algorithm __asn1_algorithm;
extern struct asn1_algorithm oid_sha256_algorithm __asn1_algorithm;
extern struct asn1_algorithm oid_sha384_algorithm __asn1_algorithm;
extern struct asn1_algorithm oid_sha512_algorithm __asn1_algorithm;
extern struct asn1_algorithm oid_sha224_algorithm __asn1_algorithm;
extern struct asn1_algorithm oid_sha512_224_algorithm __asn1_algorithm;
extern struct asn1_algorithm oid_sha512_256_algorithm __asn1_algorithm;

/** An ASN.1 bit string */
struct asn1_bit_string {
	/** Data */
	const void *data;
	/** Length */
	size_t len;
	/** Unused bits at end of data */
	unsigned int unused;
} __attribute__ (( packed ));

/**
 * Invalidate ASN.1 object cursor
 *
 * @v cursor		ASN.1 object cursor
 */
static inline __attribute__ (( always_inline )) void
asn1_invalidate_cursor ( struct asn1_cursor *cursor ) {
	cursor->len = 0;
}

/**
 * Extract ASN.1 type
 *
 * @v cursor		ASN.1 object cursor
 * @ret type		Type, or ASN1_END if cursor is invalid
 */
static inline __attribute__ (( always_inline )) unsigned int
asn1_type ( const struct asn1_cursor *cursor ) {
	const uint8_t *type = cursor->data;

	return ( ( cursor->len >= sizeof ( *type ) ) ? *type : ASN1_END );
}

/**
 * Get cursor for built object
 *
 * @v builder		ASN.1 object builder
 * @ret cursor		ASN.1 object cursor
 */
static inline __attribute__ (( always_inline )) struct asn1_cursor *
asn1_built ( struct asn1_builder *builder ) {
	union {
		struct asn1_builder builder;
		struct asn1_cursor cursor;
	} *u = container_of ( builder, typeof ( *u ), builder );

	/* Sanity check */
	build_assert ( ( ( const void * ) &u->builder.data ) ==
		       &u->cursor.data );
	build_assert ( &u->builder.len == &u->cursor.len );

	return &u->cursor;
}

extern int asn1_enter_partial ( struct asn1_cursor *cursor, unsigned int type,
				size_t *extra );
extern int asn1_enter ( struct asn1_cursor *cursor, unsigned int type );
extern int asn1_skip_if_exists ( struct asn1_cursor *cursor,
				 unsigned int type );
extern int asn1_skip ( struct asn1_cursor *cursor, unsigned int type );
extern int asn1_shrink ( struct asn1_cursor *cursor, unsigned int type );
extern int asn1_enter_any ( struct asn1_cursor *cursor );
extern int asn1_skip_any ( struct asn1_cursor *cursor );
extern int asn1_shrink_any ( struct asn1_cursor *cursor );
extern int asn1_boolean ( const struct asn1_cursor *cursor );
extern int asn1_integer ( const struct asn1_cursor *cursor, int *value );
extern int asn1_bit_string ( const struct asn1_cursor *cursor,
			     struct asn1_bit_string *bits );
extern int asn1_integral_bit_string ( const struct asn1_cursor *cursor,
				      struct asn1_bit_string *bits );
extern int asn1_compare ( const struct asn1_cursor *cursor1,
			  const struct asn1_cursor *cursor2 );
extern int asn1_algorithm ( const struct asn1_cursor *cursor,
			    struct asn1_algorithm **algorithm,
			    struct asn1_cursor *params );
extern int asn1_pubkey_algorithm ( const struct asn1_cursor *cursor,
				   struct asn1_algorithm **algorithm );
extern int asn1_digest_algorithm ( const struct asn1_cursor *cursor,
				   struct asn1_algorithm **algorithm );
extern int asn1_cipher_algorithm ( const struct asn1_cursor *cursor,
				   struct asn1_algorithm **algorithm,
				   struct asn1_cursor *params );
extern int asn1_signature_algorithm ( const struct asn1_cursor *cursor,
				      struct asn1_algorithm **algorithm );
extern int asn1_check_algorithm ( const struct asn1_cursor *cursor,
				  struct asn1_algorithm *expected );
extern int asn1_parse_cbc ( struct asn1_algorithm *algorithm,
			    struct asn1_cursor *params );
extern int asn1_parse_gcm ( struct asn1_algorithm *algorithm,
			    struct asn1_cursor *params );
extern int asn1_generalized_time ( const struct asn1_cursor *cursor,
				   time_t *time );
extern int asn1_grow ( struct asn1_builder *builder, size_t extra );
extern int asn1_prepend_raw ( struct asn1_builder *builder, const void *data,
			      size_t len );
extern int asn1_prepend ( struct asn1_builder *builder, unsigned int type,
			  const void *data, size_t len );
extern int asn1_wrap ( struct asn1_builder *builder, unsigned int type );

#endif /* _IPXE_ASN1_H */
