/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
 * All rights reserved.
 *
 * This package is an SSL implementation written
 * by Eric Young (eay@cryptsoft.com).
 * The implementation was written so as to conform with Netscapes SSL.
 *
 * This library is free for commercial and non-commercial use as long as
 * the following conditions are aheared to.  The following conditions
 * apply to all code found in this distribution, be it the RC4, RSA,
 * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
 * included with this distribution is covered by the same copyright terms
 * except that the holder is Tim Hudson (tjh@cryptsoft.com).
 *
 * Copyright remains Eric Young's, and as such any Copyright notices in
 * the code are not to be removed.
 * If this package is used in a product, Eric Young should be given attribution
 * as the author of the parts of the library used.
 * This can be in the form of a textual message at program startup or
 * in documentation (online or textual) provided with the package.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *    "This product includes cryptographic software written by
 *     Eric Young (eay@cryptsoft.com)"
 *    The word 'cryptographic' can be left out if the rouines from the library
 *    being used are not cryptographic related :-).
 * 4. If you include any Windows specific code (or a derivative thereof) from
 *    the apps directory (application code) you must include an acknowledgement:
 *    "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
 *
 * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 * The licence and distribution terms for any publically available version or
 * derivative of this code cannot be changed.  i.e. this code cannot simply be
 * copied and put under another distribution licence
 * [including the GNU Public Licence.] */

#include <openssl_grpc/asn1.h>

#include <limits.h>

#include <openssl_grpc/buf.h>
#include <openssl_grpc/err.h>
#include <openssl_grpc/mem.h>

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

#ifndef NO_OLD_ASN1
# ifndef OPENSSL_NO_FP_API

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) {
        OPENSSL_PUT_ERROR(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:
    if (b != NULL)
        BUF_MEM_free(b);
    return (ret);
}

#endif

void *ASN1_item_d2i_bio(const ASN1_ITEM *it, 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 = (const unsigned char *)b->data;
    ret = ASN1_item_d2i(x, &p, len, it);
 err:
    if (b != NULL)
        BUF_MEM_free(b);
    return (ret);
}

#ifndef OPENSSL_NO_FP_API
void *ASN1_item_d2i_fp(const ASN1_ITEM *it, FILE *in, void *x)
{
    BIO *b;
    char *ret;

    if ((b = BIO_new(BIO_s_file())) == NULL) {
        OPENSSL_PUT_ERROR(ASN1, ERR_R_BUF_LIB);
        return (NULL);
    }
    BIO_set_fp(b, in, BIO_NOCLOSE);
    ret = ASN1_item_d2i_bio(it, b, x);
    BIO_free(b);
    return (ret);
}
#endif

typedef struct asn1_const_ctx_st
    {
    const unsigned char *p;/* work char pointer */
    int eos;    /* end of sequence read for indefinite encoding */
    int error;  /* error code to use when returning an error */
    int inf;    /* constructed if 0x20, indefinite is 0x21 */
    int tag;    /* tag from last 'get object' */
    int xclass; /* class from last 'get object' */
    long slen;  /* length of last 'get object' */
    const unsigned char *max; /* largest value of p allowed */
    const unsigned char *q;/* temporary variable */
    const unsigned char **pp;/* variable */
    int line;   /* used in error processing */
    } ASN1_const_CTX;

#define HEADER_SIZE   8
#define ASN1_CHUNK_INITIAL_SIZE (16 * 1024)
static int asn1_d2i_read_bio(BIO *in, BUF_MEM **pb)
{
    BUF_MEM *b;
    unsigned char *p;
    int i;
    ASN1_const_CTX c;
    size_t want = HEADER_SIZE;
    int eos = 0;
    size_t off = 0;
    size_t len = 0;

    b = BUF_MEM_new();
    if (b == NULL) {
        OPENSSL_PUT_ERROR(ASN1, ERR_R_MALLOC_FAILURE);
        return -1;
    }

    ERR_clear_error();
    for (;;) {
        if (want >= (len - off)) {
            want -= (len - off);

            if (len + want < len || !BUF_MEM_grow_clean(b, len + want)) {
                OPENSSL_PUT_ERROR(ASN1, ERR_R_MALLOC_FAILURE);
                goto err;
            }
            i = BIO_read(in, &(b->data[len]), want);
            if ((i < 0) && ((len - off) == 0)) {
                OPENSSL_PUT_ERROR(ASN1, ASN1_R_NOT_ENOUGH_DATA);
                goto err;
            }
            if (i > 0) {
                if (len + i < len) {
                    OPENSSL_PUT_ERROR(ASN1, ASN1_R_TOO_LONG);
                    goto err;
                }
                len += i;
            }
        }
        /* else data already loaded */

        p = (unsigned char *)&(b->data[off]);
        c.p = p;
        c.inf = ASN1_get_object(&(c.p), &(c.slen), &(c.tag), &(c.xclass),
                                len - off);
        if (c.inf & 0x80) {
            uint32_t e;

            e = ERR_GET_REASON(ERR_peek_error());
            if (e != ASN1_R_TOO_LONG)
                goto err;
            else
                ERR_clear_error(); /* clear error */
        }
        i = c.p - p;            /* header length */
        off += i;               /* end of data */

        if (c.inf & 1) {
            /* no data body so go round again */
            eos++;
            if (eos < 0) {
                OPENSSL_PUT_ERROR(ASN1, ASN1_R_HEADER_TOO_LONG);
                goto err;
            }
            want = HEADER_SIZE;
        } else if (eos && (c.slen == 0) && (c.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 c.slen bytes of data */
            want = c.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) {
                    OPENSSL_PUT_ERROR(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)) {
                        OPENSSL_PUT_ERROR(ASN1, ERR_R_MALLOC_FAILURE);
                        goto err;
                    }
                    want -= chunk;
                    while (chunk > 0) {
                        i = BIO_read(in, &(b->data[len]), chunk);
                        if (i <= 0) {
                            OPENSSL_PUT_ERROR(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 + c.slen < off) {
                OPENSSL_PUT_ERROR(ASN1, ASN1_R_TOO_LONG);
                goto err;
            }
            off += c.slen;
            if (eos <= 0) {
                break;
            } else
                want = HEADER_SIZE;
        }
    }

    if (off > INT_MAX) {
        OPENSSL_PUT_ERROR(ASN1, ASN1_R_TOO_LONG);
        goto err;
    }

    *pb = b;
    return off;
 err:
    if (b != NULL)
        BUF_MEM_free(b);
    return -1;
}
