asn1.c File Reference

ASN.1 encoding. More...

#include <stdint.h>
#include <stddef.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>
#include <errno.h>
#include <time.h>
#include <ipxe/tables.h>
#include <ipxe/image.h>
#include <ipxe/asn1.h>

Go to the source code of this file.

Macros
#define	EINVAL_ASN1_EMPTY   __einfo_error ( EINFO_EINVAL_ASN1_EMPTY )
#define	EINFO_EINVAL_ASN1_EMPTY   __einfo_uniqify ( EINFO_EINVAL, 0x01, "Empty or underlength cursor" )
#define	EINVAL_ASN1_LEN_LEN   __einfo_error ( EINFO_EINVAL_ASN1_LEN_LEN )
#define	EINFO_EINVAL_ASN1_LEN_LEN   __einfo_uniqify ( EINFO_EINVAL, 0x02, "Length field overruns cursor" )
#define	EINVAL_ASN1_LEN   __einfo_error ( EINFO_EINVAL_ASN1_LEN )
#define	EINFO_EINVAL_ASN1_LEN   __einfo_uniqify ( EINFO_EINVAL, 0x03, "Field overruns cursor" )
#define	EINVAL_ASN1_BOOLEAN   __einfo_error ( EINFO_EINVAL_ASN1_BOOLEAN )
#define	EINFO_EINVAL_ASN1_BOOLEAN   __einfo_uniqify ( EINFO_EINVAL, 0x04, "Invalid boolean" )
#define	EINVAL_ASN1_INTEGER   __einfo_error ( EINFO_EINVAL_ASN1_INTEGER )
#define	EINFO_EINVAL_ASN1_INTEGER   __einfo_uniqify ( EINFO_EINVAL, 0x04, "Invalid integer" )
#define	EINVAL_ASN1_TIME   __einfo_error ( EINFO_EINVAL_ASN1_TIME )
#define	EINFO_EINVAL_ASN1_TIME   __einfo_uniqify ( EINFO_EINVAL, 0x05, "Invalid time" )
#define	EINVAL_ASN1_ALGORITHM   __einfo_error ( EINFO_EINVAL_ASN1_ALGORITHM )
#define	EINFO_EINVAL_ASN1_ALGORITHM   __einfo_uniqify ( EINFO_EINVAL, 0x06, "Invalid algorithm" )
#define	EINVAL_BIT_STRING   __einfo_error ( EINFO_EINVAL_BIT_STRING )
#define	EINFO_EINVAL_BIT_STRING   __einfo_uniqify ( EINFO_EINVAL, 0x07, "Invalid bit string" )
#define	ENOTSUP_ALGORITHM   __einfo_error ( EINFO_ENOTSUP_ALGORITHM )
#define	EINFO_ENOTSUP_ALGORITHM   __einfo_uniqify ( EINFO_ENOTSUP, 0x01, "Unsupported algorithm" )
#define	ENOTTY_ALGORITHM   __einfo_error ( EINFO_ENOTTY_ALGORITHM )
#define	EINFO_ENOTTY_ALGORITHM   __einfo_uniqify ( EINFO_ENOTTY, 0x01, "Inappropriate algorithm" )

Functions
	FILE_LICENCE (GPL2_OR_LATER_OR_UBDL)
int	asn1_start (struct asn1_cursor *cursor, unsigned int type, size_t extra)
	Start parsing ASN.1 object. More...
int	asn1_enter (struct asn1_cursor *cursor, unsigned int type)
	Enter ASN.1 object. More...
int	asn1_skip_if_exists (struct asn1_cursor *cursor, unsigned int type)
	Skip ASN.1 object if present. More...
int	asn1_skip (struct asn1_cursor *cursor, unsigned int type)
	Skip ASN.1 object. More...
int	asn1_shrink (struct asn1_cursor *cursor, unsigned int type)
	Shrink ASN.1 cursor to fit object. More...
int	asn1_enter_any (struct asn1_cursor *cursor)
	Enter ASN.1 object of any type. More...
int	asn1_skip_any (struct asn1_cursor *cursor)
	Skip ASN.1 object of any type. More...
int	asn1_shrink_any (struct asn1_cursor *cursor)
	Shrink ASN.1 object of any type. More...
int	asn1_boolean (const struct asn1_cursor *cursor)
	Parse value of ASN.1 boolean. More...
int	asn1_integer (const struct asn1_cursor *cursor, int *value)
	Parse value of ASN.1 integer. More...
int	asn1_bit_string (const struct asn1_cursor *cursor, struct asn1_bit_string *bits)
	Parse ASN.1 bit string. More...
int	asn1_integral_bit_string (const struct asn1_cursor *cursor, struct asn1_bit_string *bits)
	Parse ASN.1 bit string that must be an integral number of bytes. More...
int	asn1_compare (const struct asn1_cursor *cursor1, const struct asn1_cursor *cursor2)
	Compare two ASN.1 objects. More...
static struct asn1_algorithm *	asn1_find_algorithm (const struct asn1_cursor *cursor)
	Identify ASN.1 algorithm by OID. More...
int	asn1_algorithm (const struct asn1_cursor *cursor, struct asn1_algorithm **algorithm)
	Parse ASN.1 OID-identified algorithm. More...
int	asn1_pubkey_algorithm (const struct asn1_cursor *cursor, struct asn1_algorithm **algorithm)
	Parse ASN.1 OID-identified public-key algorithm. More...
int	asn1_digest_algorithm (const struct asn1_cursor *cursor, struct asn1_algorithm **algorithm)
	Parse ASN.1 OID-identified digest algorithm. More...
int	asn1_signature_algorithm (const struct asn1_cursor *cursor, struct asn1_algorithm **algorithm)
	Parse ASN.1 OID-identified signature algorithm. More...
int	asn1_check_algorithm (const struct asn1_cursor *cursor, struct asn1_algorithm *expected)
	Check ASN.1 OID-identified algorithm. More...
int	asn1_generalized_time (const struct asn1_cursor *cursor, time_t *time)
	Parse ASN.1 GeneralizedTime. More...
static size_t	asn1_header (struct asn1_builder_header *header, unsigned int type, size_t len)
	Construct ASN.1 header. More...
int	asn1_grow (struct asn1_builder *builder, size_t extra)
	Grow ASN.1 builder. More...
int	asn1_prepend_raw (struct asn1_builder *builder, const void *data, size_t len)
	Prepend raw data to ASN.1 builder. More...
int	asn1_prepend (struct asn1_builder *builder, unsigned int type, const void *data, size_t len)
	Prepend data to ASN.1 builder. More...
int	asn1_wrap (struct asn1_builder *builder, unsigned int type)
	Wrap ASN.1 builder. More...
int	image_asn1 (struct image *image, size_t offset, struct asn1_cursor **cursor)
	Extract ASN.1 object from image. More...
	REQUIRING_SYMBOL (image_asn1)
	REQUIRE_OBJECT (config_asn1)

Detailed Description

ASN.1 encoding.

Definition in file asn1.c.

Macro Definition Documentation

EINVAL_ASN1_EMPTY

#define EINVAL_ASN1_EMPTY   __einfo_error ( EINFO_EINVAL_ASN1_EMPTY )

Definition at line 44 of file asn1.c.

EINFO_EINVAL_ASN1_EMPTY

#define EINFO_EINVAL_ASN1_EMPTY   __einfo_uniqify ( EINFO_EINVAL, 0x01, "Empty or underlength cursor" )

Definition at line 46 of file asn1.c.

EINVAL_ASN1_LEN_LEN

#define EINVAL_ASN1_LEN_LEN   __einfo_error ( EINFO_EINVAL_ASN1_LEN_LEN )

Definition at line 48 of file asn1.c.

EINFO_EINVAL_ASN1_LEN_LEN

#define EINFO_EINVAL_ASN1_LEN_LEN   __einfo_uniqify ( EINFO_EINVAL, 0x02, "Length field overruns cursor" )

Definition at line 50 of file asn1.c.

EINVAL_ASN1_LEN

#define EINVAL_ASN1_LEN   __einfo_error ( EINFO_EINVAL_ASN1_LEN )

Definition at line 52 of file asn1.c.

EINFO_EINVAL_ASN1_LEN

#define EINFO_EINVAL_ASN1_LEN   __einfo_uniqify ( EINFO_EINVAL, 0x03, "Field overruns cursor" )

Definition at line 54 of file asn1.c.

EINVAL_ASN1_BOOLEAN

#define EINVAL_ASN1_BOOLEAN   __einfo_error ( EINFO_EINVAL_ASN1_BOOLEAN )

Definition at line 56 of file asn1.c.

EINFO_EINVAL_ASN1_BOOLEAN

#define EINFO_EINVAL_ASN1_BOOLEAN   __einfo_uniqify ( EINFO_EINVAL, 0x04, "Invalid boolean" )

Definition at line 58 of file asn1.c.

EINVAL_ASN1_INTEGER

#define EINVAL_ASN1_INTEGER   __einfo_error ( EINFO_EINVAL_ASN1_INTEGER )

Definition at line 60 of file asn1.c.

EINFO_EINVAL_ASN1_INTEGER

#define EINFO_EINVAL_ASN1_INTEGER   __einfo_uniqify ( EINFO_EINVAL, 0x04, "Invalid integer" )

Definition at line 62 of file asn1.c.

EINVAL_ASN1_TIME

#define EINVAL_ASN1_TIME   __einfo_error ( EINFO_EINVAL_ASN1_TIME )

Definition at line 64 of file asn1.c.

EINFO_EINVAL_ASN1_TIME

#define EINFO_EINVAL_ASN1_TIME   __einfo_uniqify ( EINFO_EINVAL, 0x05, "Invalid time" )

Definition at line 66 of file asn1.c.

EINVAL_ASN1_ALGORITHM

#define EINVAL_ASN1_ALGORITHM   __einfo_error ( EINFO_EINVAL_ASN1_ALGORITHM )

Definition at line 68 of file asn1.c.

EINFO_EINVAL_ASN1_ALGORITHM

#define EINFO_EINVAL_ASN1_ALGORITHM   __einfo_uniqify ( EINFO_EINVAL, 0x06, "Invalid algorithm" )

Definition at line 70 of file asn1.c.

EINVAL_BIT_STRING

#define EINVAL_BIT_STRING   __einfo_error ( EINFO_EINVAL_BIT_STRING )

Definition at line 72 of file asn1.c.

EINFO_EINVAL_BIT_STRING

#define EINFO_EINVAL_BIT_STRING   __einfo_uniqify ( EINFO_EINVAL, 0x07, "Invalid bit string" )

Definition at line 74 of file asn1.c.

ENOTSUP_ALGORITHM

#define ENOTSUP_ALGORITHM   __einfo_error ( EINFO_ENOTSUP_ALGORITHM )

Definition at line 76 of file asn1.c.

EINFO_ENOTSUP_ALGORITHM

#define EINFO_ENOTSUP_ALGORITHM   __einfo_uniqify ( EINFO_ENOTSUP, 0x01, "Unsupported algorithm" )

Definition at line 78 of file asn1.c.

ENOTTY_ALGORITHM

#define ENOTTY_ALGORITHM   __einfo_error ( EINFO_ENOTTY_ALGORITHM )

Definition at line 80 of file asn1.c.

EINFO_ENOTTY_ALGORITHM

#define EINFO_ENOTTY_ALGORITHM   __einfo_uniqify ( EINFO_ENOTTY, 0x01, "Inappropriate algorithm" )

Definition at line 82 of file asn1.c.

Function Documentation

FILE_LICENCE()

FILE_LICENCE

(

GPL2_OR_LATER_OR_UBDL

)

asn1_start()

int asn1_start	(	struct asn1_cursor *	cursor,
		unsigned int	type,
		size_t	extra
	)

Start parsing ASN.1 object.

Parameters

cursor	ASN.1 object cursor
type	Expected type, or ASN1_ANY
extra	Additional length not present within partial cursor

Return values

len	Length of object body, or negative error

The object cursor will be updated to point to the start of the object body (i.e. the first byte following the length byte(s)), and the length of the object body (i.e. the number of bytes until the following object tag, if any) is returned.

Definition at line 98 of file asn1.c.

                                                                               {
        unsigned int len_len;
        unsigned int len;

        /* Sanity check */
        if ( cursor->len < 2 /* Tag byte and first length byte */ ) {
                if ( cursor->len )
                        DBGC ( cursor, "ASN1 %p too short\n", cursor );
                return -EINVAL_ASN1_EMPTY;
        }

        /* Check the tag byte */
        if ( ( type != ASN1_ANY ) && ( type != asn1_type ( cursor ) ) ) {
                DBGC ( cursor, "ASN1 %p type mismatch (expected %d, got %d)\n",
                       cursor, type, *( ( uint8_t * ) cursor->data ) );
                return -ENXIO;
        }
        cursor->data++;
        cursor->len--;

        /* Extract length of the length field and sanity check */
        len_len = *( ( uint8_t * ) cursor->data );
        if ( len_len & 0x80 ) {
                len_len = ( len_len & 0x7f );
                cursor->data++;
                cursor->len--;
        } else {
                len_len = 1;
        }
        if ( cursor->len < len_len ) {
                DBGC ( cursor, "ASN1 %p bad length field length %d (max "
                       "%zd)\n", cursor, len_len, cursor->len );
                return -EINVAL_ASN1_LEN_LEN;
        }

        /* Extract the length and sanity check */
        for ( len = 0 ; len_len ; len_len-- ) {
                len <<= 8;
                len |= *( ( uint8_t * ) cursor->data );
                cursor->data++;
                cursor->len--;
        }
        if ( ( cursor->len + extra ) < len ) {
                DBGC ( cursor, "ASN1 %p bad length %d (max %zd)\n",
                       cursor, len, ( cursor->len + extra ) );
                return -EINVAL_ASN1_LEN;
        }

        return len;
}

References ASN1_ANY, asn1_type(), asn1_cursor::data, DBGC, EINVAL_ASN1_EMPTY, EINVAL_ASN1_LEN, EINVAL_ASN1_LEN_LEN, ENXIO, extra, len, asn1_cursor::len, and type.

Referenced by asn1_enter(), asn1_shrink(), asn1_skip_if_exists(), and der_probe().

asn1_enter()

int asn1_enter	(	struct asn1_cursor *	cursor,
		unsigned int	type
	)

Enter ASN.1 object.

Parameters

cursor	ASN.1 object cursor
type	Expected type, or ASN1_ANY

Return values

rc	Return status code

The object cursor will be updated to point to the body of the current ASN.1 object. If any error occurs, the object cursor will be invalidated.

Definition at line 160 of file asn1.c.

                                                                 {
        int len;

        len = asn1_start ( cursor, type, 0 );
        if ( len < 0 ) {
                asn1_invalidate_cursor ( cursor );
                return len;
        }

        cursor->len = len;
        DBGC ( cursor, "ASN1 %p entered object type %02x (len %x)\n",
               cursor, type, len );

        return 0;
}

References asn1_invalidate_cursor(), asn1_start(), DBGC, len, asn1_cursor::len, and type.

Referenced by asn1_algorithm(), asn1_bit_string(), asn1_boolean(), asn1_enter_any(), asn1_generalized_time(), asn1_integer(), cms_parse(), cms_parse_certificates(), cms_parse_content_type(), cms_parse_signature_value(), cms_parse_signer_identifier(), cms_parse_signer_info(), ocsp_compare_responder_key_hash(), ocsp_parse_basic_response(), ocsp_parse_cert_id(), ocsp_parse_certs(), ocsp_parse_response(), ocsp_parse_response_bytes(), ocsp_parse_response_status(), ocsp_parse_response_type(), ocsp_parse_responses(), ocsp_parse_tbs_response_data(), ocsp_request(), rsa_parse_integer(), rsa_parse_mod_exp(), validator_append(), x509_parse(), x509_parse_access_description(), x509_parse_authority_info_access(), x509_parse_basic_constraints(), x509_parse_common_name(), x509_parse_extended_key_usage(), x509_parse_extension(), x509_parse_extensions(), x509_parse_key_purpose(), x509_parse_ocsp(), x509_parse_public_key(), x509_parse_subject_alt_name(), x509_parse_tbscertificate(), x509_parse_validity(), and x509_parse_version().

asn1_skip_if_exists()

int asn1_skip_if_exists	(	struct asn1_cursor *	cursor,
		unsigned int	type
	)

Skip ASN.1 object if present.

Parameters

cursor	ASN.1 object cursor
type	Expected type, or ASN1_ANY

Return values

rc	Return status code

The object cursor will be updated to point to the next ASN.1 object. If any error occurs, the object cursor will not be modified.

Definition at line 187 of file asn1.c.

                                                                          {
        int len;

        len = asn1_start ( cursor, type, 0 );
        if ( len < 0 )
                return len;

        cursor->data += len;
        cursor->len -= len;
        DBGC ( cursor, "ASN1 %p skipped object type %02x (len %x)\n",
               cursor, type, len );

        if ( ! cursor->len ) {
                DBGC ( cursor, "ASN1 %p reached end of object\n", cursor );
                return -ENOENT;
        }

        return 0;
}

References asn1_start(), asn1_cursor::data, DBGC, ENOENT, len, asn1_cursor::len, and type.

Referenced by asn1_skip(), cms_parse(), cms_parse_signer_info(), and ocsp_parse_tbs_response_data().

asn1_skip()

int asn1_skip	(	struct asn1_cursor *	cursor,
		unsigned int	type
	)

Skip ASN.1 object.

Parameters

cursor	ASN.1 object cursor
type	Expected type, or ASN1_ANY

Return values

rc	Return status code

The object cursor will be updated to point to the next ASN.1 object. If any error occurs, the object cursor will be invalidated.

Definition at line 218 of file asn1.c.

                                                                {
        int rc;

        if ( ( rc = asn1_skip_if_exists ( cursor, type ) ) != 0 ) {
                asn1_invalidate_cursor ( cursor );
                return rc;
        }

        return 0;
}

References asn1_invalidate_cursor(), asn1_skip_if_exists(), rc, and type.

Referenced by asn1_skip_any(), cms_parse(), cms_parse_signer_info(), ocsp_parse_cert_id(), ocsp_request(), and rsa_parse_mod_exp().

asn1_shrink()

int asn1_shrink	(	struct asn1_cursor *	cursor,
		unsigned int	type
	)

Shrink ASN.1 cursor to fit object.

Parameters

cursor	ASN.1 object cursor
type	Expected type, or ASN1_ANY

Return values

rc	Return status code

The object cursor will be shrunk to contain only the current ASN.1 object. If any error occurs, the object cursor will be invalidated.

Definition at line 240 of file asn1.c.

                                                                  {
        struct asn1_cursor temp;
        const void *end;
        int len;

        /* Find end of object */
        memcpy ( &temp, cursor, sizeof ( temp ) );
        len = asn1_start ( &temp, type, 0 );
        if ( len < 0 ) {
                asn1_invalidate_cursor ( cursor );
                return len;
        }
        end = ( temp.data + len );

        /* Shrink original cursor to contain only its first object */
        cursor->len = ( end - cursor->data );

        return 0;
}

References asn1_invalidate_cursor(), asn1_start(), asn1_cursor::data, end, len, asn1_cursor::len, memcpy(), and type.

Referenced by asn1_shrink_any(), cms_parse_signer_identifier(), ocsp_parse_cert_id(), x509_parse_issuer(), and x509_parse_serial().

asn1_enter_any()

int asn1_enter_any

(

struct asn1_cursor *

cursor

)

Enter ASN.1 object of any type.

Parameters

cursor

ASN.1 object cursor

Return values

rc	Return status code

Definition at line 266 of file asn1.c.

                                                  {
        return asn1_enter ( cursor, ASN1_ANY );
}

References ASN1_ANY, and asn1_enter().

Referenced by ocsp_parse_responder_id(), x509_check_alt_name(), and x509_parse_common_name().

asn1_skip_any()

int asn1_skip_any

(

struct asn1_cursor *

cursor

)

Skip ASN.1 object of any type.

Parameters

cursor

ASN.1 object cursor

Return values

rc	Return status code

Definition at line 276 of file asn1.c.

                                                 {
        return asn1_skip ( cursor, ASN1_ANY );
}

References ASN1_ANY, and asn1_skip().

Referenced by cms_parse(), cms_parse_certificates(), cms_parse_signer_identifier(), cms_parse_signer_info(), ocsp_parse_basic_response(), ocsp_parse_certs(), ocsp_parse_response(), ocsp_parse_response_bytes(), ocsp_parse_responses(), ocsp_parse_tbs_response_data(), rsa_parse_mod_exp(), validator_append(), x509_check_name(), x509_parse(), x509_parse_access_description(), x509_parse_authority_info_access(), x509_parse_basic_constraints(), x509_parse_common_name(), x509_parse_extended_key_usage(), x509_parse_extension(), x509_parse_extensions(), x509_parse_public_key(), x509_parse_tbscertificate(), and x509_parse_validity().

asn1_shrink_any()

int asn1_shrink_any

(

struct asn1_cursor *

cursor

)

Shrink ASN.1 object of any type.

Parameters

cursor

ASN.1 object cursor

Return values

rc	Return status code

Definition at line 286 of file asn1.c.

                                                   {
        return asn1_shrink ( cursor, ASN1_ANY );
}

References ASN1_ANY, and asn1_shrink().

Referenced by cms_signature(), ocsp_parse_tbs_response_data(), x509_certificate(), x509_parse_public_key(), x509_parse_subject(), and x509_parse_tbscertificate().

asn1_boolean()

int asn1_boolean

(

const struct asn1_cursor *

cursor

)

Parse value of ASN.1 boolean.

Parameters

cursor

ASN.1 object cursor

Return values

value

Value, or negative error

Definition at line 296 of file asn1.c.

                                                      {
        struct asn1_cursor contents;
        const struct {
                uint8_t value;
        } __attribute__ (( packed )) *boolean;

        /* Enter boolean */
        memcpy ( &contents, cursor, sizeof ( contents ) );
        asn1_enter ( &contents, ASN1_BOOLEAN );
        if ( contents.len != sizeof ( *boolean ) )
                return -EINVAL_ASN1_BOOLEAN;

        /* Extract value */
        boolean = contents.data;
        return boolean->value;
}

References __attribute__, ASN1_BOOLEAN, asn1_enter(), asn1_cursor::data, EINVAL_ASN1_BOOLEAN, asn1_cursor::len, memcpy(), and value.

Referenced by x509_parse_basic_constraints(), and x509_parse_extension().

asn1_integer()

int asn1_integer	(	const struct asn1_cursor *	cursor,
		int *	value
	)

Parse value of ASN.1 integer.

Parameters

cursor	ASN.1 object cursor
value	Value to fill in

Return values

rc	Return status code

Definition at line 320 of file asn1.c.

                                                                  {
        struct asn1_cursor contents;
        uint8_t high_byte;
        int rc;

        /* Enter integer */
        memcpy ( &contents, cursor, sizeof ( contents ) );
        if ( ( rc = asn1_enter ( &contents, ASN1_INTEGER ) ) != 0 )
                return rc;
        if ( contents.len < 1 )
                return -EINVAL_ASN1_INTEGER;

        /* Initialise value according to sign byte */
        *value = *( ( int8_t * ) contents.data );
        contents.data++;
        contents.len--;

        /* Process value */
        while ( contents.len ) {
                high_byte = ( (*value) >> ( 8 * ( sizeof ( *value ) - 1 ) ) );
                if ( ( high_byte != 0x00 ) && ( high_byte != 0xff ) ) {
                        DBGC ( cursor, "ASN1 %p integer overflow\n", cursor );
                        return -EINVAL_ASN1_INTEGER;
                }
                *value = ( ( *value << 8 ) | *( ( uint8_t * ) contents.data ) );
                contents.data++;
                contents.len--;
        }

        return 0;
}

References asn1_enter(), ASN1_INTEGER, asn1_cursor::data, DBGC, EINVAL_ASN1_INTEGER, asn1_cursor::len, memcpy(), rc, and value.

Referenced by x509_parse_basic_constraints(), and x509_parse_version().

asn1_bit_string()

int asn1_bit_string	(	const struct asn1_cursor *	cursor,
		struct asn1_bit_string *	bits
	)

Parse ASN.1 bit string.

Parameters

cursor	ASN.1 cursor
bits	Bit string to fill in

Return values

rc	Return status code

Definition at line 359 of file asn1.c.

                                                     {
        struct asn1_cursor contents;
        const struct {
                uint8_t unused;
                uint8_t data[0];
        } __attribute__ (( packed )) *bit_string;
        size_t len;
        unsigned int unused;
        uint8_t unused_mask;
        const uint8_t *last;
        int rc;

        /* Enter bit string */
        memcpy ( &contents, cursor, sizeof ( contents ) );
        if ( ( rc = asn1_enter ( &contents, ASN1_BIT_STRING ) ) != 0 ) {
                DBGC ( cursor, "ASN1 %p cannot locate bit string:\n", cursor );
                DBGC_HDA ( cursor, 0, cursor->data, cursor->len );
                return rc;
        }

        /* Validity checks */
        if ( contents.len < sizeof ( *bit_string ) ) {
                DBGC ( cursor, "ASN1 %p invalid bit string:\n", cursor );
                DBGC_HDA ( cursor, 0, cursor->data, cursor->len );
                return -EINVAL_BIT_STRING;
        }
        bit_string = contents.data;
        len = ( contents.len - offsetof ( typeof ( *bit_string ), data ) );
        unused = bit_string->unused;
        unused_mask = ( 0xff >> ( 8 - unused ) );
        last = ( bit_string->data + len - 1 );
        if ( ( unused >= 8 ) ||
             ( ( unused > 0 ) && ( len == 0 ) ) ||
             ( ( *last & unused_mask ) != 0 ) ) {
                DBGC ( cursor, "ASN1 %p invalid bit string:\n", cursor );
                DBGC_HDA ( cursor, 0, cursor->data, cursor->len );
                return -EINVAL_BIT_STRING;
        }

        /* Populate bit string */
        bits->data = &bit_string->data;
        bits->len = len;
        bits->unused = unused;

        return 0;
}

References __attribute__, ASN1_BIT_STRING, asn1_enter(), bits, data, asn1_cursor::data, DBGC, DBGC_HDA, EINVAL_BIT_STRING, last, len, asn1_cursor::len, memcpy(), offsetof, rc, typeof(), and unused.

asn1_integral_bit_string()

int asn1_integral_bit_string	(	const struct asn1_cursor *	cursor,
		struct asn1_bit_string *	bits
	)

Parse ASN.1 bit string that must be an integral number of bytes.

Parameters

cursor	ASN.1 cursor
bits	Bit string to fill in

Return values

rc	Return status code

Definition at line 414 of file asn1.c.

                                                              {
        int rc;

        /* Parse bit string */
        if ( ( rc = asn1_bit_string ( cursor, bits ) ) != 0 )
                return rc;

        /* Check that there are no unused bits at end of string */
        if ( bits->unused ) {
                DBGC ( cursor, "ASN1 %p invalid integral bit string:\n",
                       cursor );
                DBGC_HDA ( cursor, 0, cursor->data, cursor->len );
                return -EINVAL_BIT_STRING;
        }

        return 0;
}

References bits, asn1_cursor::data, DBGC, DBGC_HDA, EINVAL_BIT_STRING, asn1_cursor::len, and rc.

Referenced by ocsp_parse_basic_response(), rsa_parse_mod_exp(), and x509_parse().

asn1_compare()

int asn1_compare	(	const struct asn1_cursor *	cursor1,
		const struct asn1_cursor *	cursor2
	)

Compare two ASN.1 objects.

Parameters

cursor1	ASN.1 object cursor
cursor2	ASN.1 object cursor

Return values

difference

Difference as returned by memcmp()

Note that invalid and empty cursors will compare as equal with each other.

Definition at line 443 of file asn1.c.

                                                       {
        int difference;

        difference = ( cursor2->len - cursor1->len );
        return ( difference ? difference :
                 memcmp ( cursor1->data, cursor2->data, cursor1->len ) );
}

References asn1_cursor::data, asn1_cursor::len, and memcmp().

Referenced by asn1_find_algorithm(), certstore_find(), cms_find_issuer_serial(), cms_parse_content_type(), ocsp_compare_responder_name(), ocsp_parse_cert_id(), ocsp_parse_response_type(), rsa_match(), validator_step(), x509_check_issuer(), x509_find_access_method(), x509_find_extension(), x509_find_subject(), x509_parse_common_name(), and x509_parse_key_purpose().

asn1_find_algorithm()

static struct asn1_algorithm* asn1_find_algorithm ( const struct asn1_cursor *  cursor )

static

Identify ASN.1 algorithm by OID.

Parameters

cursor

ASN.1 object cursor

Return values

algorithm

Algorithm, or NULL

Definition at line 460 of file asn1.c.

                                                         {
        struct asn1_algorithm *algorithm;

        for_each_table_entry ( algorithm, ASN1_ALGORITHMS ) {
                if ( asn1_compare ( &algorithm->oid, cursor ) == 0 )
                        return algorithm;
        }

        return NULL;
}

References algorithm, ASN1_ALGORITHMS, asn1_compare(), for_each_table_entry, and NULL.

Referenced by asn1_algorithm().

asn1_algorithm()

int asn1_algorithm	(	const struct asn1_cursor *	cursor,
		struct asn1_algorithm **	algorithm
	)

Parse ASN.1 OID-identified algorithm.

Parameters

cursor

ASN.1 object cursor

Return values

algorithm	Algorithm
rc	Return status code

Definition at line 478 of file asn1.c.

                                                         {
        struct asn1_cursor contents;
        int rc;

        /* Enter signatureAlgorithm */
        memcpy ( &contents, cursor, sizeof ( contents ) );
        asn1_enter ( &contents, ASN1_SEQUENCE );

        /* Enter algorithm */
        if ( ( rc = asn1_enter ( &contents, ASN1_OID ) ) != 0 ) {
                DBGC ( cursor, "ASN1 %p cannot locate algorithm OID:\n",
                       cursor );
                DBGC_HDA ( cursor, 0, cursor->data, cursor->len );
                return -EINVAL_ASN1_ALGORITHM;
        }

        /* Identify algorithm */
        *algorithm = asn1_find_algorithm ( &contents );
        if ( ! *algorithm ) {
                DBGC ( cursor, "ASN1 %p unrecognised algorithm:\n", cursor );
                DBGC_HDA ( cursor, 0, cursor->data, cursor->len );
                return -ENOTSUP_ALGORITHM;
        }

        return 0;
}

References algorithm, asn1_enter(), asn1_find_algorithm(), ASN1_OID, ASN1_SEQUENCE, asn1_cursor::data, DBGC, DBGC_HDA, EINVAL_ASN1_ALGORITHM, ENOTSUP_ALGORITHM, asn1_cursor::len, memcpy(), and rc.

asn1_pubkey_algorithm()

int asn1_pubkey_algorithm	(	const struct asn1_cursor *	cursor,
		struct asn1_algorithm **	algorithm
	)

Parse ASN.1 OID-identified public-key algorithm.

Parameters

cursor

ASN.1 object cursor

Return values

algorithm	Algorithm
rc	Return status code

Definition at line 513 of file asn1.c.

                                                                {
        int rc;

        /* Parse algorithm */
        if ( ( rc = asn1_algorithm ( cursor, algorithm ) ) != 0 )
                return rc;

        /* Check algorithm has a public key */
        if ( ! (*algorithm)->pubkey ) {
                DBGC ( cursor, "ASN1 %p algorithm %s is not a public-key "
                       "algorithm:\n", cursor, (*algorithm)->name );
                DBGC_HDA ( cursor, 0, cursor->data, cursor->len );
                return -ENOTTY_ALGORITHM;
        }

        return 0;
}

References algorithm, asn1_cursor::data, DBGC, DBGC_HDA, ENOTTY_ALGORITHM, asn1_cursor::len, and rc.

Referenced by cms_parse_signature_algorithm(), and x509_parse_public_key().

asn1_digest_algorithm()

int asn1_digest_algorithm	(	const struct asn1_cursor *	cursor,
		struct asn1_algorithm **	algorithm
	)

Parse ASN.1 OID-identified digest algorithm.

Parameters

cursor

ASN.1 object cursor

Return values

algorithm	Algorithm
rc	Return status code

Definition at line 539 of file asn1.c.

                                                                {
        int rc;

        /* Parse algorithm */
        if ( ( rc = asn1_algorithm ( cursor, algorithm ) ) != 0 )
                return rc;

        /* Check algorithm has a digest */
        if ( ! (*algorithm)->digest ) {
                DBGC ( cursor, "ASN1 %p algorithm %s is not a digest "
                       "algorithm:\n", cursor, (*algorithm)->name );
                DBGC_HDA ( cursor, 0, cursor->data, cursor->len );
                return -ENOTTY_ALGORITHM;
        }

        return 0;
}

References algorithm, asn1_cursor::data, DBGC, DBGC_HDA, ENOTTY_ALGORITHM, asn1_cursor::len, and rc.

Referenced by cms_parse_digest_algorithm().

asn1_signature_algorithm()

int asn1_signature_algorithm	(	const struct asn1_cursor *	cursor,
		struct asn1_algorithm **	algorithm
	)

Parse ASN.1 OID-identified signature algorithm.

Parameters

cursor

ASN.1 object cursor

Return values

algorithm	Algorithm
rc	Return status code

Definition at line 565 of file asn1.c.

                                                                   {
        int rc;

        /* Parse algorithm */
        if ( ( rc = asn1_algorithm ( cursor, algorithm ) ) != 0 )
                return rc;

        /* Check algorithm has a public key */
        if ( ! (*algorithm)->pubkey ) {
                DBGC ( cursor, "ASN1 %p algorithm %s is not a signature "
                       "algorithm:\n", cursor, (*algorithm)->name );
                DBGC_HDA ( cursor, 0, cursor->data, cursor->len );
                return -ENOTTY_ALGORITHM;
        }

        /* Check algorithm has a digest */
        if ( ! (*algorithm)->digest ) {
                DBGC ( cursor, "ASN1 %p algorithm %s is not a signature "
                       "algorithm:\n", cursor, (*algorithm)->name );
                DBGC_HDA ( cursor, 0, cursor->data, cursor->len );
                return -ENOTTY_ALGORITHM;
        }

        return 0;
}

References algorithm, asn1_cursor::data, DBGC, DBGC_HDA, ENOTTY_ALGORITHM, asn1_cursor::len, and rc.

Referenced by ocsp_parse_basic_response(), x509_parse(), and x509_parse_tbscertificate().

asn1_check_algorithm()

int asn1_check_algorithm	(	const struct asn1_cursor *	cursor,
		struct asn1_algorithm *	expected
	)

Check ASN.1 OID-identified algorithm.

Parameters

cursor	ASN.1 object cursor
expected	Expected algorithm

Return values

rc	Return status code

Definition at line 599 of file asn1.c.

                                                             {
        struct asn1_algorithm *actual;
        int rc;

        /* Parse algorithm */
        if ( ( rc = asn1_algorithm ( cursor, &actual ) ) != 0 )
                return rc;

        /* Check algorithm matches */
        if ( actual != expected ) {
                DBGC ( cursor, "ASN1 %p algorithm %s does not match %s\n",
                       cursor, actual->name, expected->name );
                return -ENOTTY_ALGORITHM;
        }

        return 0;
}

References DBGC, ENOTTY_ALGORITHM, asn1_algorithm::name, and rc.

Referenced by rsa_parse_mod_exp().

asn1_generalized_time()

int asn1_generalized_time	(	const struct asn1_cursor *	cursor,
		time_t *	time
	)

Parse ASN.1 GeneralizedTime.

Parameters

cursor	ASN.1 cursor
time	Time to fill in

Return values

rc	Return status code

RFC 5280 section 4.1.2.5 places several restrictions on the allowed formats for UTCTime and GeneralizedTime, and mandates the interpretation of centuryless year values.

Definition at line 629 of file asn1.c.

                                                                             {
        struct asn1_cursor contents;
        unsigned int have_century;
        unsigned int type;
        union {
                struct {
                        uint8_t century;
                        uint8_t year;
                        uint8_t month;
                        uint8_t day;
                        uint8_t hour;
                        uint8_t minute;
                        uint8_t second;
                } __attribute__ (( packed )) named;
                uint8_t raw[7];
        } pairs;
        struct tm tm;
        const uint8_t *data;
        size_t remaining;
        unsigned int tens;
        unsigned int units;
        unsigned int i;
        int rc;

        /* Determine time format utcTime/generalizedTime */
        memcpy ( &contents, cursor, sizeof ( contents ) );
        type = asn1_type ( &contents );
        switch ( type ) {
        case ASN1_UTC_TIME:
                have_century = 0;
                break;
        case ASN1_GENERALIZED_TIME:
                have_century = 1;
                break;
        default:
                DBGC ( cursor, "ASN1 %p invalid time type %02x\n",
                       cursor, type );
                DBGC_HDA ( cursor, 0, cursor->data, cursor->len );
                return -EINVAL_ASN1_TIME;
        }

        /* Enter utcTime/generalizedTime */
        if ( ( rc = asn1_enter ( &contents, type ) ) != 0 ) {
                DBGC ( cursor, "ASN1 %p cannot locate %s time:\n", cursor,
                       ( ( type == ASN1_UTC_TIME ) ? "UTC" : "generalized" ) );
                DBGC_HDA ( cursor, 0, cursor->data, cursor->len );
                return rc;
        }

        /* Parse digit string a pair at a time */
        memset ( &pairs, 0, sizeof ( pairs ) );
        data = contents.data;
        remaining = contents.len;
        for ( i = ( have_century ? 0 : 1 ) ; i < sizeof ( pairs.raw ) ; i++ ) {
                if ( remaining < 2 ) {
                        /* Some certificates violate the X.509 RFC by
                         * omitting the "seconds" value.
                         */
                        if ( i == ( sizeof ( pairs.raw ) - 1 ) )
                                break;
                        DBGC ( cursor, "ASN1 %p invalid time:\n", cursor );
                        DBGC_HDA ( cursor, 0, cursor->data, cursor->len );
                        return -EINVAL_ASN1_TIME;
                }
                tens = data[0];
                units = data[1];
                if ( ! ( isdigit ( tens ) && isdigit ( units ) ) ) {
                        DBGC ( cursor, "ASN1 %p invalid time:\n", cursor );
                        DBGC_HDA ( cursor, 0, cursor->data, cursor->len );
                        return -EINVAL_ASN1_TIME;
                }
                pairs.raw[i] = ( ( 10 * ( tens - '0' ) ) + ( units - '0' ) );
                data += 2;
                remaining -= 2;
        }

        /* Determine century if applicable */
        if ( ! have_century )
                pairs.named.century = ( ( pairs.named.year >= 50 ) ? 19 : 20 );

        /* Check for trailing "Z" */
        if ( ( remaining != 1 ) || ( data[0] != 'Z' ) ) {
                DBGC ( cursor, "ASN1 %p invalid time:\n", cursor );
                DBGC_HDA ( cursor, 0, cursor->data, cursor->len );
                return -EINVAL_ASN1_TIME;
        }

        /* Fill in time */
        tm.tm_year = ( ( ( pairs.named.century - 19 ) * 100 ) +
                       pairs.named.year );
        tm.tm_mon = ( pairs.named.month - 1 );
        tm.tm_mday = pairs.named.day;
        tm.tm_hour = pairs.named.hour;
        tm.tm_min = pairs.named.minute;
        tm.tm_sec = pairs.named.second;

        /* Convert to seconds since the Epoch */
        *time = mktime ( &tm );

        return 0;
}

References __attribute__, asn1_enter(), ASN1_GENERALIZED_TIME, asn1_type(), ASN1_UTC_TIME, data, asn1_cursor::data, DBGC, DBGC_HDA, EINVAL_ASN1_TIME, isdigit(), asn1_cursor::len, memcpy(), memset(), mktime(), raw, rc, second, time, tm::tm_hour, tm::tm_mday, tm::tm_min, tm::tm_mon, tm::tm_sec, tm::tm_year, and type.

Referenced by ocsp_parse_responses(), and x509_parse_validity().

asn1_header()

static size_t asn1_header ( struct asn1_builder_header *  header, unsigned int  type, size_t  len  )

static

Construct ASN.1 header.

Parameters

header	ASN.1 builder header
type	Type
len	Content length

Return values

header_len

Header length

Definition at line 739 of file asn1.c.

                                                            {
        unsigned int header_len = 2;
        unsigned int len_len = 0;
        size_t temp;

        /* Construct header */
        header->type = type;
        if ( len < 0x80 ) {
                header->length[0] = len;
        } else {
                for ( temp = len ; temp ; temp >>= 8 )
                        len_len++;
                header->length[0] = ( 0x80 | len_len );
                header_len += len_len;
                for ( temp = len ; temp ; temp >>= 8 )
                        header->length[len_len--] = ( temp & 0xff );
        }

        return header_len;
}

References header, len, and type.

Referenced by asn1_prepend(), and asn1_wrap().

asn1_grow()

int asn1_grow	(	struct asn1_builder *	builder,
		size_t	extra
	)

Grow ASN.1 builder.

Parameters

builder	ASN.1 builder
extra	Extra space to prepend

Return values

rc	Return status code

Definition at line 768 of file asn1.c.

                                                             {
        size_t new_len;
        void *new;

        /* As with the ASN1 parsing functions, make errors permanent */
        if ( builder->len && ! builder->data )
                return -ENOMEM;

        /* Reallocate data buffer */
        new_len = ( builder->len + extra );
        new = realloc ( builder->data, new_len );
        if ( ! new ) {
                free ( builder->data );
                builder->data = NULL;
                return -ENOMEM;
        }
        builder->data = new;

        /* Move existing data to end of buffer */
        memmove ( ( builder->data + extra ), builder->data, builder->len );
        builder->len = new_len;

        return 0;
}

References asn1_builder::data, ENOMEM, extra, free, asn1_builder::len, memmove(), NULL, and realloc().

Referenced by asn1_prepend(), asn1_prepend_raw(), asn1_wrap(), and icert_cert().

asn1_prepend_raw()

int asn1_prepend_raw	(	struct asn1_builder *	builder,
		const void *	data,
		size_t	len
	)

Prepend raw data to ASN.1 builder.

Parameters

builder	ASN.1 builder
data	Data to prepend
len	Length of data to prepend

Return values

rc	Return status code

Definition at line 801 of file asn1.c.

                                    {
        int rc;

        /* Grow buffer */
        if ( ( rc = asn1_grow ( builder, len ) ) != 0 )
                return rc;

        /* Populate data buffer */
        memcpy ( builder->data, data, len );

        return 0;
}

References asn1_grow(), data, asn1_builder::data, len, memcpy(), and rc.

Referenced by icert_cert(), icert_certs(), and ocsp_request().

asn1_prepend()

int asn1_prepend	(	struct asn1_builder *	builder,
		unsigned int	type,
		const void *	data,
		size_t	len
	)

Prepend data to ASN.1 builder.

Parameters

builder	ASN.1 builder
type	Type
data	Data to prepend
len	Length of data to prepend

Return values

rc	Return status code

Definition at line 824 of file asn1.c.

                                                  {
        struct asn1_builder_header header;
        size_t header_len;
        int rc;

        /* Construct header */
        header_len = asn1_header ( &header, type, len );

        /* Grow buffer */
        if ( ( rc = asn1_grow ( builder, header_len + len ) ) != 0 )
                return rc;

        /* Populate data buffer */
        memcpy ( builder->data, &header, header_len );
        memcpy ( ( builder->data + header_len ), data, len );

        return 0;
}

References asn1_grow(), asn1_header(), data, asn1_builder::data, header, len, memcpy(), rc, and type.

Referenced by icert_certs(), and ocsp_request().

asn1_wrap()

int asn1_wrap	(	struct asn1_builder *	builder,
		unsigned int	type
	)

Wrap ASN.1 builder.

Parameters

builder	ASN.1 builder
type	Type

Return values

rc	Return status code

Definition at line 851 of file asn1.c.

                                                                  {
        struct asn1_builder_header header;
        size_t header_len;
        int rc;

        /* Construct header */
        header_len = asn1_header ( &header, type, builder->len );

        /* Grow buffer */
        if ( ( rc = asn1_grow ( builder, header_len ) ) != 0 )
                return rc;

        /* Populate data buffer */
        memcpy ( builder->data, &header, header_len );

        return 0;
}

References asn1_grow(), asn1_header(), asn1_builder::data, header, asn1_builder::len, memcpy(), rc, and type.

Referenced by icert_cert(), icert_certs(), and ocsp_request().

image_asn1()

int image_asn1	(	struct image *	image,
		size_t	offset,
		struct asn1_cursor **	cursor
	)

Extract ASN.1 object from image.

Parameters

image	Image
offset	Offset within image
cursor	ASN.1 cursor to fill in

Return values

next	Offset to next image, or negative error

The caller is responsible for eventually calling free() on the allocated ASN.1 cursor.

Definition at line 880 of file asn1.c.

                                               {
        int next;
        int rc;

        /* Sanity check */
        assert ( offset <= image->len );

        /* Check that this image can be used to extract an ASN.1 object */
        if ( ! ( image->type && image->type->asn1 ) )
                return -ENOTSUP;

        /* Try creating ASN.1 cursor */
        next = image->type->asn1 ( image, offset, cursor );
        if ( next < 0 ) {
                rc = next;
                DBGC ( image, "IMAGE %s could not extract ASN.1 object: %s\n",
                       image->name, strerror ( rc ) );
                return rc;
        }

        return next;
}

References image_type::asn1, assert(), DBGC, ENOTSUP, len, image::name, next, offset, rc, strerror(), and image::type.

Referenced by asn1_okx(), image_x509(), and imgverify().

REQUIRING_SYMBOL()

REQUIRING_SYMBOL

(

image_asn1

)

REQUIRE_OBJECT()

REQUIRE_OBJECT

(

config_asn1

)