mirror of
https://github.com/pineappleEA/pineapple-src.git
synced 2024-12-11 23:08:25 -05:00
469 lines
9.4 KiB
C
469 lines
9.4 KiB
C
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/* $OpenBSD: bs_cbb.c,v 1.23 2020/09/16 05:52:04 jsing Exp $ */
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/*
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* Copyright (c) 2014, Google Inc.
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*
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* Permission to use, copy, modify, and/or distribute this software for any
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* purpose with or without fee is hereby granted, provided that the above
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* copyright notice and this permission notice appear in all copies.
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*
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* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
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* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
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* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
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* SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
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* WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
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* OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
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* CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */
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#include <stdlib.h>
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#include <string.h>
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#include <openssl/opensslconf.h>
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#include "bytestring.h"
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#define CBB_INITIAL_SIZE 64
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static int
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cbb_init(CBB *cbb, uint8_t *buf, size_t cap)
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{
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struct cbb_buffer_st *base;
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if ((base = calloc(1, sizeof(struct cbb_buffer_st))) == NULL)
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return 0;
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base->buf = buf;
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base->len = 0;
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base->cap = cap;
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base->can_resize = 1;
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cbb->base = base;
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cbb->is_top_level = 1;
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return 1;
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}
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int
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CBB_init(CBB *cbb, size_t initial_capacity)
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{
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uint8_t *buf = NULL;
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memset(cbb, 0, sizeof(*cbb));
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if (initial_capacity == 0)
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initial_capacity = CBB_INITIAL_SIZE;
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if ((buf = calloc(1, initial_capacity)) == NULL)
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return 0;
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if (!cbb_init(cbb, buf, initial_capacity)) {
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free(buf);
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return 0;
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}
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return 1;
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}
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int
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CBB_init_fixed(CBB *cbb, uint8_t *buf, size_t len)
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{
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memset(cbb, 0, sizeof(*cbb));
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if (!cbb_init(cbb, buf, len))
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return 0;
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cbb->base->can_resize = 0;
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return 1;
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}
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void
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CBB_cleanup(CBB *cbb)
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{
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if (cbb->base) {
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if (cbb->base->can_resize)
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freezero(cbb->base->buf, cbb->base->cap);
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free(cbb->base);
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}
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cbb->base = NULL;
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cbb->child = NULL;
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}
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static int
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cbb_buffer_add(struct cbb_buffer_st *base, uint8_t **out, size_t len)
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{
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size_t newlen;
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if (base == NULL)
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return 0;
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newlen = base->len + len;
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if (newlen < base->len)
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/* Overflow */
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return 0;
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if (newlen > base->cap) {
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size_t newcap = base->cap * 2;
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uint8_t *newbuf;
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if (!base->can_resize)
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return 0;
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if (newcap < base->cap || newcap < newlen)
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newcap = newlen;
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newbuf = recallocarray(base->buf, base->cap, newcap, 1);
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if (newbuf == NULL)
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return 0;
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base->buf = newbuf;
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base->cap = newcap;
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}
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if (out)
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*out = base->buf + base->len;
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base->len = newlen;
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return 1;
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}
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static int
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cbb_add_u(CBB *cbb, uint32_t v, size_t len_len)
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{
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uint8_t *buf;
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size_t i;
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if (len_len == 0)
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return 1;
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if (len_len > 4)
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return 0;
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if (!CBB_flush(cbb) || !cbb_buffer_add(cbb->base, &buf, len_len))
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return 0;
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for (i = len_len - 1; i < len_len; i--) {
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buf[i] = v;
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v >>= 8;
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}
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return 1;
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}
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int
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CBB_finish(CBB *cbb, uint8_t **out_data, size_t *out_len)
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{
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if (!cbb->is_top_level)
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return 0;
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if (!CBB_flush(cbb))
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return 0;
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if (cbb->base->can_resize && (out_data == NULL || out_len == NULL))
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/*
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* |out_data| and |out_len| can only be NULL if the CBB is
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* fixed.
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*/
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return 0;
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if (out_data != NULL)
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*out_data = cbb->base->buf;
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if (out_len != NULL)
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*out_len = cbb->base->len;
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cbb->base->buf = NULL;
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CBB_cleanup(cbb);
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return 1;
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}
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/*
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* CBB_flush recurses and then writes out any pending length prefix. The current
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* length of the underlying base is taken to be the length of the
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* length-prefixed data.
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*/
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int
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CBB_flush(CBB *cbb)
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{
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size_t child_start, i, len;
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if (cbb->base == NULL)
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return 0;
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if (cbb->child == NULL || cbb->pending_len_len == 0)
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return 1;
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child_start = cbb->offset + cbb->pending_len_len;
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if (!CBB_flush(cbb->child) || child_start < cbb->offset ||
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cbb->base->len < child_start)
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return 0;
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len = cbb->base->len - child_start;
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if (cbb->pending_is_asn1) {
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/*
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* For ASN.1, we assumed that we were using short form which
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* only requires a single byte for the length octet.
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*
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* If it turns out that we need long form, we have to move
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* the contents along in order to make space for more length
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* octets.
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*/
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size_t len_len = 1; /* total number of length octets */
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uint8_t initial_length_byte;
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/* We already wrote 1 byte for the length. */
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if (cbb->pending_len_len != 1)
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return 0;
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/* Check for long form */
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if (len > 0xfffffffe)
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return 0; /* 0xffffffff is reserved */
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else if (len > 0xffffff)
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len_len = 5;
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else if (len > 0xffff)
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len_len = 4;
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else if (len > 0xff)
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len_len = 3;
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else if (len > 0x7f)
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len_len = 2;
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if (len_len == 1) {
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/* For short form, the initial byte is the length. */
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initial_length_byte = len;
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len = 0;
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} else {
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/*
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* For long form, the initial byte is the number of
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* subsequent length octets (plus bit 8 set).
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*/
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initial_length_byte = 0x80 | (len_len - 1);
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/*
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* We need to move the contents along in order to make
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* space for the long form length octets.
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*/
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size_t extra_bytes = len_len - 1;
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if (!cbb_buffer_add(cbb->base, NULL, extra_bytes))
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return 0;
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memmove(cbb->base->buf + child_start + extra_bytes,
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cbb->base->buf + child_start, len);
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}
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cbb->base->buf[cbb->offset++] = initial_length_byte;
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cbb->pending_len_len = len_len - 1;
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}
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for (i = cbb->pending_len_len - 1; i < cbb->pending_len_len; i--) {
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cbb->base->buf[cbb->offset + i] = len;
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len >>= 8;
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}
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if (len != 0)
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return 0;
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cbb->child->base = NULL;
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cbb->child = NULL;
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cbb->pending_len_len = 0;
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cbb->pending_is_asn1 = 0;
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cbb->offset = 0;
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return 1;
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}
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void
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CBB_discard_child(CBB *cbb)
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{
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if (cbb->child == NULL)
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return;
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cbb->base->len = cbb->offset;
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cbb->child->base = NULL;
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cbb->child = NULL;
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cbb->pending_len_len = 0;
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cbb->pending_is_asn1 = 0;
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cbb->offset = 0;
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}
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static int
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cbb_add_length_prefixed(CBB *cbb, CBB *out_contents, size_t len_len)
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{
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uint8_t *prefix_bytes;
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if (!CBB_flush(cbb))
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return 0;
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cbb->offset = cbb->base->len;
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if (!cbb_buffer_add(cbb->base, &prefix_bytes, len_len))
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return 0;
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memset(prefix_bytes, 0, len_len);
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memset(out_contents, 0, sizeof(CBB));
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out_contents->base = cbb->base;
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cbb->child = out_contents;
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cbb->pending_len_len = len_len;
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cbb->pending_is_asn1 = 0;
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return 1;
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}
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int
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CBB_add_u8_length_prefixed(CBB *cbb, CBB *out_contents)
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{
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return cbb_add_length_prefixed(cbb, out_contents, 1);
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}
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int
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CBB_add_u16_length_prefixed(CBB *cbb, CBB *out_contents)
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{
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return cbb_add_length_prefixed(cbb, out_contents, 2);
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}
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int
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CBB_add_u24_length_prefixed(CBB *cbb, CBB *out_contents)
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{
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return cbb_add_length_prefixed(cbb, out_contents, 3);
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}
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int
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CBB_add_asn1(CBB *cbb, CBB *out_contents, unsigned int tag)
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{
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if (tag > UINT8_MAX)
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return 0;
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/* Long form identifier octets are not supported. */
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if ((tag & 0x1f) == 0x1f)
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return 0;
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/* Short-form identifier octet only needs a single byte */
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if (!CBB_flush(cbb) || !CBB_add_u8(cbb, tag))
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return 0;
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/*
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* Add 1 byte to cover the short-form length octet case. If it turns
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* out we need long-form, it will be extended later.
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*/
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cbb->offset = cbb->base->len;
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if (!CBB_add_u8(cbb, 0))
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return 0;
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memset(out_contents, 0, sizeof(CBB));
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out_contents->base = cbb->base;
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cbb->child = out_contents;
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cbb->pending_len_len = 1;
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cbb->pending_is_asn1 = 1;
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return 1;
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}
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int
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CBB_add_bytes(CBB *cbb, const uint8_t *data, size_t len)
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{
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uint8_t *dest;
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if (!CBB_flush(cbb) || !cbb_buffer_add(cbb->base, &dest, len))
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return 0;
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memcpy(dest, data, len);
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return 1;
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}
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int
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CBB_add_space(CBB *cbb, uint8_t **out_data, size_t len)
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{
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if (!CBB_flush(cbb) || !cbb_buffer_add(cbb->base, out_data, len))
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return 0;
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memset(*out_data, 0, len);
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return 1;
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}
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int
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CBB_add_u8(CBB *cbb, size_t value)
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{
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if (value > UINT8_MAX)
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return 0;
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return cbb_add_u(cbb, (uint32_t)value, 1);
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}
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int
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CBB_add_u16(CBB *cbb, size_t value)
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{
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if (value > UINT16_MAX)
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return 0;
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return cbb_add_u(cbb, (uint32_t)value, 2);
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}
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int
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CBB_add_u24(CBB *cbb, size_t value)
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{
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if (value > 0xffffffUL)
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return 0;
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return cbb_add_u(cbb, (uint32_t)value, 3);
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}
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int
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CBB_add_u32(CBB *cbb, size_t value)
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{
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if (value > 0xffffffffUL)
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return 0;
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return cbb_add_u(cbb, (uint32_t)value, 4);
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}
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int
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CBB_add_asn1_uint64(CBB *cbb, uint64_t value)
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{
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CBB child;
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size_t i;
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int started = 0;
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if (!CBB_add_asn1(cbb, &child, CBS_ASN1_INTEGER))
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return 0;
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for (i = 0; i < 8; i++) {
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uint8_t byte = (value >> 8 * (7 - i)) & 0xff;
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/*
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* ASN.1 restriction: first 9 bits cannot be all zeroes or
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* all ones. Since this function only encodes unsigned
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* integers, the only concerns are not encoding leading
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* zeros and adding a padding byte if necessary.
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*
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* In practice, this means:
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* 1) Skip leading octets of all zero bits in the value
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* 2) After skipping the leading zero octets, if the next 9
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* bits are all ones, add an all zero prefix octet (and
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* set the high bit of the prefix octet if negative).
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*
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* Additionally, for an unsigned value, add an all zero
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* prefix if the high bit of the first octet would be one.
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*/
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if (!started) {
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if (byte == 0)
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/* Don't encode leading zeros. */
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continue;
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/*
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* If the high bit is set, add a padding byte to make it
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* unsigned.
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*/
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if ((byte & 0x80) && !CBB_add_u8(&child, 0))
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return 0;
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started = 1;
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}
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if (!CBB_add_u8(&child, byte))
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return 0;
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}
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/* 0 is encoded as a single 0, not the empty string. */
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if (!started && !CBB_add_u8(&child, 0))
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return 0;
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||
|
|
||
|
return CBB_flush(cbb);
|
||
|
}
|