/*

 * Copyright 1995-2021 The OpenSSL Project Authors. All Rights Reserved.

 *

 * Licensed under the Apache License 2.0 (the "License").  You may not use

 * this file except in compliance with the License.  You can obtain a copy

 * in the file LICENSE in the source distribution or at

 * https://www.openssl.org/source/license.html

 */

#include <stdio.h>

#include <limits.h>

#include "internal/cryptlib.h"

#include "internal/numbers.h"

#include <openssl/buffer.h>

#include <openssl/asn1.h>

#include "internal/asn1.h"

#include "crypto/asn1.h"

#ifndef NO_OLD_ASN1

# ifndef OPENSSL_NO_STDIO

void *ASN1_d2i_fp(void *(*xnew) (void), d2i_of_void *d2i, FILE *in, void **x)

{

    BIO *b;

    void *ret;

    if ((b = BIO_new(BIO_s_file())) == NULL) {

        ERR_raise(ERR_LIB_ASN1, ERR_R_BUF_LIB);

        return NULL;

    }

    BIO_set_fp(b, in, BIO_NOCLOSE);

    ret = ASN1_d2i_bio(xnew, d2i, b, x);

    BIO_free(b);

    return ret;

}

# endif

void *ASN1_d2i_bio(void *(*xnew) (void), d2i_of_void *d2i, BIO *in, void **x)

{

    BUF_MEM *b = NULL;

    const unsigned char *p;

    void *ret = NULL;

    int len;

    len = asn1_d2i_read_bio(in, &b);

    if (len < 0)

        goto err;

    p = (unsigned char *)b->data;

    ret = d2i(x, &p, len);

 err:

    BUF_MEM_free(b);

    return ret;

}

#endif

void *ASN1_item_d2i_bio_ex(const ASN1_ITEM *it, BIO *in, void *x,

                           OSSL_LIB_CTX *libctx, const char *propq)

{

    BUF_MEM *b = NULL;

    const unsigned char *p;

    void *ret = NULL;

    int len;

    if (in == NULL)

        return NULL;

    len = asn1_d2i_read_bio(in, &b);

    if (len < 0)

        goto err;

    p = (const unsigned char *)b->data;

    ret = ASN1_item_d2i_ex(x, &p, len, it, libctx, propq);

 err:

    BUF_MEM_free(b);

    return ret;

}

void *ASN1_item_d2i_bio(const ASN1_ITEM *it, BIO *in, void *x)

{

    return ASN1_item_d2i_bio_ex(it, in, x, NULL, NULL);

}

#ifndef OPENSSL_NO_STDIO

void *ASN1_item_d2i_fp_ex(const ASN1_ITEM *it, FILE *in, void *x,

                          OSSL_LIB_CTX *libctx, const char *propq)

{

    BIO *b;

    char *ret;

    if ((b = BIO_new(BIO_s_file())) == NULL) {

        ERR_raise(ERR_LIB_ASN1, ERR_R_BUF_LIB);

        return NULL;

    }

    BIO_set_fp(b, in, BIO_NOCLOSE);

    ret = ASN1_item_d2i_bio_ex(it, b, x, libctx, propq);

    BIO_free(b);

    return ret;

}

void *ASN1_item_d2i_fp(const ASN1_ITEM *it, FILE *in, void *x)

{

    return ASN1_item_d2i_fp_ex(it, in, x, NULL, NULL);

}

#endif

#define HEADER_SIZE   8

#define ASN1_CHUNK_INITIAL_SIZE (16 * 1024)

int asn1_d2i_read_bio(BIO *in, BUF_MEM **pb)

{

    BUF_MEM *b;

    unsigned char *p;

    int i;

    size_t want = HEADER_SIZE;

    uint32_t eos = 0;

    size_t off = 0;

    size_t len = 0;

    size_t diff;

    const unsigned char *q;

    long slen;

    int inf, tag, xclass;

    b = BUF_MEM_new();

    if (b == NULL) {

        ERR_raise(ERR_LIB_ASN1, ERR_R_BUF_LIB);

        return -1;

    }

    ERR_set_mark();

    for (;;) {

        diff = len - off;

        if (want >= diff) {

            want -= diff;

            if (len + want < len || !BUF_MEM_grow_clean(b, len + want)) {

                ERR_raise(ERR_LIB_ASN1, ERR_R_BUF_LIB);

                goto err;

            }

            i = BIO_read(in, &(b->data[len]), want);

            if (i < 0 && diff == 0) {

                ERR_raise(ERR_LIB_ASN1, ASN1_R_NOT_ENOUGH_DATA);

                goto err;

            }

            if (i > 0) {

                if (len + i < len) {

                    ERR_raise(ERR_LIB_ASN1, ASN1_R_TOO_LONG);

                    goto err;

                }

                len += i;

            }

        }

        /* else data already loaded */

        p = (unsigned char *)&(b->data[off]);

        q = p;

        diff = len - off;

        if (diff == 0)

            goto err;

        inf = ASN1_get_object(&q, &slen, &tag, &xclass, diff);

        if (inf & 0x80) {

            unsigned long e;

            e = ERR_GET_REASON(ERR_peek_last_error());

            if (e != ASN1_R_TOO_LONG)

                goto err;

            ERR_pop_to_mark();

        }

        i = q - p;            /* header length */

        off += i;               /* end of data */

        if (inf & 1) {

            /* no data body so go round again */

            if (eos == UINT32_MAX) {

                ERR_raise(ERR_LIB_ASN1, ASN1_R_HEADER_TOO_LONG);

                goto err;

            }

            eos++;

            want = HEADER_SIZE;

        } else if (eos && (slen == 0) && (tag == V_ASN1_EOC)) {

            /* eos value, so go back and read another header */

            eos--;

            if (eos == 0)

                break;

            else

                want = HEADER_SIZE;

        } else {

            /* suck in slen bytes of data */

            want = slen;

            if (want > (len - off)) {

                size_t chunk_max = ASN1_CHUNK_INITIAL_SIZE;

                want -= (len - off);

                if (want > INT_MAX /* BIO_read takes an int length */  ||

                    len + want < len) {

                    ERR_raise(ERR_LIB_ASN1, ASN1_R_TOO_LONG);

                    goto err;

                }

                while (want > 0) {

                    /*

                     * Read content in chunks of increasing size

                     * so we can return an error for EOF without

                     * having to allocate the entire content length

                     * in one go.

                     */

                    size_t chunk = want > chunk_max ? chunk_max : want;

                    if (!BUF_MEM_grow_clean(b, len + chunk)) {

                        ERR_raise(ERR_LIB_ASN1, ERR_R_BUF_LIB);

                        goto err;

                    }

                    want -= chunk;

                    while (chunk > 0) {

                        i = BIO_read(in, &(b->data[len]), chunk);

                        if (i <= 0) {

                            ERR_raise(ERR_LIB_ASN1, ASN1_R_NOT_ENOUGH_DATA);

                            goto err;

                        }

                    /*

                     * This can't overflow because |len+want| didn't

                     * overflow.

                     */

                        len += i;

                        chunk -= i;

                    }

                    if (chunk_max < INT_MAX/2)

                        chunk_max *= 2;

                }

            }

            if (off + slen < off) {

                ERR_raise(ERR_LIB_ASN1, ASN1_R_TOO_LONG);

                goto err;

            }

            off += slen;

            if (eos == 0) {

                break;

            } else

                want = HEADER_SIZE;

        }

    }

    if (off > INT_MAX) {

        ERR_raise(ERR_LIB_ASN1, ASN1_R_TOO_LONG);

        goto err;

    }

    *pb = b;

    return off;

 err:

    ERR_clear_last_mark();

    BUF_MEM_free(b);

    return -1;

}