X-Git-Url: https://gerrit.opnfv.org/gerrit/gitweb?a=blobdiff_plain;f=qemu%2Froms%2Fipxe%2Fsrc%2Fcrypto%2Fasn1.c;fp=qemu%2Froms%2Fipxe%2Fsrc%2Fcrypto%2Fasn1.c;h=6d880704f3b369d6b65bb8a52f84903ac1933a6a;hb=e44e3482bdb4d0ebde2d8b41830ac2cdb07948fb;hp=0000000000000000000000000000000000000000;hpb=9ca8dbcc65cfc63d6f5ef3312a33184e1d726e00;p=kvmfornfv.git diff --git a/qemu/roms/ipxe/src/crypto/asn1.c b/qemu/roms/ipxe/src/crypto/asn1.c new file mode 100644 index 000000000..6d880704f --- /dev/null +++ b/qemu/roms/ipxe/src/crypto/asn1.c @@ -0,0 +1,847 @@ +/* + * Copyright (C) 2007 Michael Brown . + * + * 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 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. + */ + +FILE_LICENCE ( GPL2_OR_LATER ); + +#include +#include +#include +#include +#include +#include +#include +#include +#include + +/** @file + * + * ASN.1 encoding + * + */ + +/* Disambiguate the various error causes */ +#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" ) + +/** + * Invalidate ASN.1 object cursor + * + * @v cursor ASN.1 object cursor + */ +void asn1_invalidate_cursor ( struct asn1_cursor *cursor ) { + static uint8_t asn1_invalid_object[] = { ASN1_END, 0 }; + + cursor->data = asn1_invalid_object; + cursor->len = 0; +} + +/** + * Start parsing ASN.1 object + * + * @v cursor ASN.1 object cursor + * @v type Expected type, or ASN1_ANY + * @ret 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. + */ +static int asn1_start ( struct asn1_cursor *cursor, unsigned int type ) { + 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 < len ) { + DBGC ( cursor, "ASN1 %p bad length %d (max %zd)\n", + cursor, len, cursor->len ); + return -EINVAL_ASN1_LEN; + } + + return len; +} + +/** + * Enter ASN.1 object + * + * @v cursor ASN.1 object cursor + * @v type Expected type, or ASN1_ANY + * @ret 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. + */ +int asn1_enter ( struct asn1_cursor *cursor, unsigned int type ) { + int len; + + len = asn1_start ( cursor, type ); + 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; +} + +/** + * Skip ASN.1 object if present + * + * @v cursor ASN.1 object cursor + * @v type Expected type, or ASN1_ANY + * @ret 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. + */ +int asn1_skip_if_exists ( struct asn1_cursor *cursor, unsigned int type ) { + int len; + + len = asn1_start ( cursor, type ); + 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; +} + +/** + * Skip ASN.1 object + * + * @v cursor ASN.1 object cursor + * @v type Expected type, or ASN1_ANY + * @ret 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. + */ +int asn1_skip ( struct asn1_cursor *cursor, unsigned int type ) { + int rc; + + if ( ( rc = asn1_skip_if_exists ( cursor, type ) ) != 0 ) { + asn1_invalidate_cursor ( cursor ); + return rc; + } + + return 0; +} + +/** + * Shrink ASN.1 cursor to fit object + * + * @v cursor ASN.1 object cursor + * @v type Expected type, or ASN1_ANY + * @ret 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. + */ +int asn1_shrink ( struct asn1_cursor *cursor, unsigned int type ) { + struct asn1_cursor temp; + const void *end; + int len; + + /* Find end of object */ + memcpy ( &temp, cursor, sizeof ( temp ) ); + len = asn1_start ( &temp, type ); + 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; +} + +/** + * Enter ASN.1 object of any type + * + * @v cursor ASN.1 object cursor + * @ret rc Return status code + */ +int asn1_enter_any ( struct asn1_cursor *cursor ) { + return asn1_enter ( cursor, ASN1_ANY ); +} + +/** + * Skip ASN.1 object of any type + * + * @v cursor ASN.1 object cursor + * @ret rc Return status code + */ +int asn1_skip_any ( struct asn1_cursor *cursor ) { + return asn1_skip ( cursor, ASN1_ANY ); +} + +/** + * Shrink ASN.1 object of any type + * + * @v cursor ASN.1 object cursor + * @ret rc Return status code + */ +int asn1_shrink_any ( struct asn1_cursor *cursor ) { + return asn1_shrink ( cursor, ASN1_ANY ); +} + +/** + * Parse value of ASN.1 boolean + * + * @v cursor ASN.1 object cursor + * @ret value Value, or negative error + */ +int asn1_boolean ( const struct asn1_cursor *cursor ) { + 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; +} + +/** + * Parse value of ASN.1 integer + * + * @v cursor ASN.1 object cursor + * @v value Value to fill in + * @ret rc Return status code + */ +int asn1_integer ( const struct asn1_cursor *cursor, int *value ) { + 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; +} + +/** + * Parse ASN.1 bit string + * + * @v cursor ASN.1 cursor + * @v bits Bit string to fill in + * @ret rc Return status code + */ +int asn1_bit_string ( const struct asn1_cursor *cursor, + struct asn1_bit_string *bits ) { + 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; +} + +/** + * Parse ASN.1 bit string that must be an integral number of bytes + * + * @v cursor ASN.1 cursor + * @v bits Bit string to fill in + * @ret rc Return status code + */ +int asn1_integral_bit_string ( const struct asn1_cursor *cursor, + struct asn1_bit_string *bits ) { + 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; +} + +/** + * Compare two ASN.1 objects + * + * @v cursor1 ASN.1 object cursor + * @v cursor2 ASN.1 object cursor + * @ret difference Difference as returned by memcmp() + * + * Note that invalid and empty cursors will compare as equal with each + * other. + */ +int asn1_compare ( const struct asn1_cursor *cursor1, + const struct asn1_cursor *cursor2 ) { + int difference; + + difference = ( cursor2->len - cursor1->len ); + return ( difference ? difference : + memcmp ( cursor1->data, cursor2->data, cursor1->len ) ); +} + +/** + * Identify ASN.1 algorithm by OID + * + * @v cursor ASN.1 object cursor + + * @ret algorithm Algorithm, or NULL + */ +static struct asn1_algorithm * +asn1_find_algorithm ( const struct asn1_cursor *cursor ) { + struct asn1_algorithm *algorithm; + + for_each_table_entry ( algorithm, ASN1_ALGORITHMS ) { + if ( asn1_compare ( &algorithm->oid, cursor ) == 0 ) + return algorithm; + } + + return NULL; +} + +/** + * Parse ASN.1 OID-identified algorithm + * + * @v cursor ASN.1 object cursor + * @ret algorithm Algorithm + * @ret rc Return status code + */ +int asn1_algorithm ( const struct asn1_cursor *cursor, + struct asn1_algorithm **algorithm ) { + 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; +} + +/** + * Parse ASN.1 OID-identified public-key algorithm + * + * @v cursor ASN.1 object cursor + * @ret algorithm Algorithm + * @ret rc Return status code + */ +int asn1_pubkey_algorithm ( const struct asn1_cursor *cursor, + struct asn1_algorithm **algorithm ) { + 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; +} + +/** + * Parse ASN.1 OID-identified digest algorithm + * + * @v cursor ASN.1 object cursor + * @ret algorithm Algorithm + * @ret rc Return status code + */ +int asn1_digest_algorithm ( const struct asn1_cursor *cursor, + struct asn1_algorithm **algorithm ) { + 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; +} + +/** + * Parse ASN.1 OID-identified signature algorithm + * + * @v cursor ASN.1 object cursor + * @ret algorithm Algorithm + * @ret rc Return status code + */ +int asn1_signature_algorithm ( const struct asn1_cursor *cursor, + struct asn1_algorithm **algorithm ) { + 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; +} + +/** + * Parse ASN.1 GeneralizedTime + * + * @v cursor ASN.1 cursor + * @v time Time to fill in + * @ret 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. + */ +int asn1_generalized_time ( const struct asn1_cursor *cursor, time_t *time ) { + 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; +} + +/** + * Construct ASN.1 header + * + * @v header ASN.1 builder header + * @v type Type + * @v len Content length + * @ret header_len Header length + */ +static size_t asn1_header ( struct asn1_builder_header *header, + unsigned int type, size_t len ) { + 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; +} + +/** + * Grow ASN.1 builder + * + * @v builder ASN.1 builder + * @v extra Extra space to prepend + * @ret rc Return status code + */ +static int asn1_grow ( struct asn1_builder *builder, size_t extra ) { + 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; +} + +/** + * Prepend raw data to ASN.1 builder + * + * @v builder ASN.1 builder + * @v data Data to prepend + * @v len Length of data to prepend + * @ret rc Return status code + */ +int asn1_prepend_raw ( struct asn1_builder *builder, const void *data, + size_t len ) { + int rc; + + /* Grow buffer */ + if ( ( rc = asn1_grow ( builder, len ) ) != 0 ) + return rc; + + /* Populate data buffer */ + memcpy ( builder->data, data, len ); + + return 0; +} + +/** + * Prepend data to ASN.1 builder + * + * @v builder ASN.1 builder + * @v type Type + * @v data Data to prepend + * @v len Length of data to prepend + * @ret rc Return status code + */ +int asn1_prepend ( struct asn1_builder *builder, unsigned int type, + const void *data, size_t len ) { + 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; +} + +/** + * Wrap ASN.1 builder + * + * @v builder ASN.1 builder + * @v type Type + * @ret rc Return status code + */ +int asn1_wrap ( struct asn1_builder *builder, unsigned int type ) { + 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; +}