chromium/third_party/boringssl/src/crypto/bytestring/ber.c

/* Copyright (c) 2014, Google Inc.
 *
 * Permission to use, copy, modify, and/or distribute this software for any
 * purpose with or without fee is hereby granted, provided that the above
 * copyright notice and this permission notice appear in all copies.
 *
 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY
 * SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION
 * OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
 * CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. */

#include <openssl/bytestring.h>

#include <assert.h>
#include <string.h>

#include "internal.h"


// kMaxDepth limits the recursion depth to avoid overflowing the stack.
static const uint32_t kMaxDepth = …;

// is_string_type returns one if |tag| is a string type and zero otherwise. It
// ignores the constructed bit.
static int is_string_type(CBS_ASN1_TAG tag) { … }

// cbs_find_ber walks an ASN.1 structure in |orig_in| and sets |*ber_found|
// depending on whether an indefinite length element or constructed string was
// found. The value of |orig_in| is not changed. It returns one on success (i.e.
// |*ber_found| was set) and zero on error.
static int cbs_find_ber(const CBS *orig_in, int *ber_found, uint32_t depth) { … }

// cbs_get_eoc returns one if |cbs| begins with an "end of contents" (EOC) value
// and zero otherwise. If an EOC was found, it advances |cbs| past it.
static int cbs_get_eoc(CBS *cbs) { … }

// cbs_convert_ber reads BER data from |in| and writes DER data to |out|. If
// |string_tag| is non-zero, then all elements must match |string_tag| up to the
// constructed bit and primitive element bodies are written to |out| without
// element headers. This is used when concatenating the fragments of a
// constructed string. If |looking_for_eoc| is set then any EOC elements found
// will cause the function to return after consuming it. It returns one on
// success and zero on error.
static int cbs_convert_ber(CBS *in, CBB *out, CBS_ASN1_TAG string_tag,
                           int looking_for_eoc, uint32_t depth) { … }

int CBS_asn1_ber_to_der(CBS *in, CBS *out, uint8_t **out_storage) { … }

int CBS_get_asn1_implicit_string(CBS *in, CBS *out, uint8_t **out_storage,
                                 CBS_ASN1_TAG outer_tag,
                                 CBS_ASN1_TAG inner_tag) { … }