/*

 * Copyright 1998-2026 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

 *

 * Uses brotli compression library from https://github.com/google/brotli

 */

#include <stdio.h>

#include <stdlib.h>

#include <string.h>

#include <openssl/objects.h>

#include "internal/comp.h"

#include <openssl/err.h>

#include "crypto/cryptlib.h"

#include "internal/bio.h"

#include "internal/thread_once.h"

#include "comp_local.h"

COMP_METHOD *COMP_brotli(void);

#ifdef OPENSSL_NO_BROTLI

#undef BROTLI_SHARED

#else

#include <brotli/decode.h>

#include <brotli/encode.h>

/* memory allocations functions for brotli initialisation */

static void *brotli_alloc(void *opaque, size_t size)

{

    return OPENSSL_zalloc(size);

}

static void brotli_free(void *opaque, void *address)

{

    OPENSSL_free(address);

}

/*

 * When OpenSSL is built on Windows, we do not want to require that

 * the BROTLI.DLL be available in order for the OpenSSL DLLs to

 * work.  Therefore, all BROTLI routines are loaded at run time

 * and we do not link to a .LIB file when BROTLI_SHARED is set.

 */

#if defined(OPENSSL_SYS_WINDOWS) || defined(OPENSSL_SYS_WIN32)

#include <windows.h>

#endif

#ifdef BROTLI_SHARED

#include "internal/dso.h"

/* Function pointers */

typedef BrotliEncoderState *(*encode_init_ft)(brotli_alloc_func, brotli_free_func, void *);

typedef BROTLI_BOOL (*encode_stream_ft)(BrotliEncoderState *, BrotliEncoderOperation, size_t *, const uint8_t **, size_t *, uint8_t **, size_t *);

typedef BROTLI_BOOL (*encode_has_more_ft)(BrotliEncoderState *);

typedef void (*encode_end_ft)(BrotliEncoderState *);

typedef BROTLI_BOOL (*encode_oneshot_ft)(int, int, BrotliEncoderMode, size_t, const uint8_t in[], size_t *, uint8_t out[]);

typedef BrotliDecoderState *(*decode_init_ft)(brotli_alloc_func, brotli_free_func, void *);

typedef BROTLI_BOOL (*decode_stream_ft)(BrotliDecoderState *, size_t *, const uint8_t **, size_t *, uint8_t **, size_t *);

typedef BROTLI_BOOL (*decode_has_more_ft)(BrotliDecoderState *);

typedef void (*decode_end_ft)(BrotliDecoderState *);

typedef BrotliDecoderErrorCode (*decode_error_ft)(BrotliDecoderState *);

typedef const char *(*decode_error_string_ft)(BrotliDecoderErrorCode);

typedef BROTLI_BOOL (*decode_is_finished_ft)(BrotliDecoderState *);

typedef BrotliDecoderResult (*decode_oneshot_ft)(size_t, const uint8_t in[], size_t *, uint8_t out[]);

static encode_init_ft p_encode_init = NULL;

static encode_stream_ft p_encode_stream = NULL;

static encode_has_more_ft p_encode_has_more = NULL;

static encode_end_ft p_encode_end = NULL;

static encode_oneshot_ft p_encode_oneshot = NULL;

static decode_init_ft p_decode_init = NULL;

static decode_stream_ft p_decode_stream = NULL;

static decode_has_more_ft p_decode_has_more = NULL;

static decode_end_ft p_decode_end = NULL;

static decode_error_ft p_decode_error = NULL;

static decode_error_string_ft p_decode_error_string = NULL;

static decode_is_finished_ft p_decode_is_finished = NULL;

static decode_oneshot_ft p_decode_oneshot = NULL;

static DSO *brotli_encode_dso = NULL;

static DSO *brotli_decode_dso = NULL;

#define BrotliEncoderCreateInstance p_encode_init

#define BrotliEncoderCompressStream p_encode_stream

#define BrotliEncoderHasMoreOutput p_encode_has_more

#define BrotliEncoderDestroyInstance p_encode_end

#define BrotliEncoderCompress p_encode_oneshot

#define BrotliDecoderCreateInstance p_decode_init

#define BrotliDecoderDecompressStream p_decode_stream

#define BrotliDecoderHasMoreOutput p_decode_has_more

#define BrotliDecoderDestroyInstance p_decode_end

#define BrotliDecoderGetErrorCode p_decode_error

#define BrotliDecoderErrorString p_decode_error_string

#define BrotliDecoderIsFinished p_decode_is_finished

#define BrotliDecoderDecompress p_decode_oneshot

#endif /* ifdef BROTLI_SHARED */

struct brotli_state {

    BrotliEncoderState *encoder;

    BrotliDecoderState *decoder;

};

static int brotli_stateful_init(COMP_CTX *ctx)

{

    struct brotli_state *state = OPENSSL_zalloc(sizeof(*state));

    if (state == NULL)

        return 0;

    state->encoder = BrotliEncoderCreateInstance(brotli_alloc, brotli_free, NULL);

    if (state->encoder == NULL)

        goto err;

    state->decoder = BrotliDecoderCreateInstance(brotli_alloc, brotli_free, NULL);

    if (state->decoder == NULL)

        goto err;

    ctx->data = state;

    return 1;

err:

    BrotliDecoderDestroyInstance(state->decoder);

    BrotliEncoderDestroyInstance(state->encoder);

    OPENSSL_free(state);

    return 0;

}

static void brotli_stateful_finish(COMP_CTX *ctx)

{

    struct brotli_state *state = ctx->data;

    if (state != NULL) {

        BrotliDecoderDestroyInstance(state->decoder);

        BrotliEncoderDestroyInstance(state->encoder);

        OPENSSL_free(state);

        ctx->data = NULL;

    }

}

static ossl_ssize_t brotli_stateful_compress_block(COMP_CTX *ctx, unsigned char *out,

    size_t olen, unsigned char *in,

    size_t ilen)

{

    BROTLI_BOOL done;

    struct brotli_state *state = ctx->data;

    size_t in_avail = ilen;

    size_t out_avail = olen;

    if (state == NULL || olen > OSSL_SSIZE_MAX)

        return -1;

    if (ilen == 0)

        return 0;

    /*

     * The finish API does not provide a final output buffer,

     * so each compress operation has to be flushed, if all

     * the input data can't be accepted, or there is more output,

     * this has to be considered an error, since there is no more

     * output buffer space

     */

    done = BrotliEncoderCompressStream(state->encoder, BROTLI_OPERATION_FLUSH,

        &in_avail, (const uint8_t **)&in,

        &out_avail, &out, NULL);

    if (done == BROTLI_FALSE

        || in_avail != 0

        || BrotliEncoderHasMoreOutput(state->encoder))

        return -1;

    if (out_avail > olen)

        return -1;

    return (ossl_ssize_t)(olen - out_avail);

}

static ossl_ssize_t brotli_stateful_expand_block(COMP_CTX *ctx, unsigned char *out,

    size_t olen, unsigned char *in,

    size_t ilen)

{

    BrotliDecoderResult result;

    struct brotli_state *state = ctx->data;

    size_t in_avail = ilen;

    size_t out_avail = olen;

    if (state == NULL || olen > OSSL_SSIZE_MAX)

        return -1;

    if (ilen == 0)

        return 0;

    result = BrotliDecoderDecompressStream(state->decoder, &in_avail,

        (const uint8_t **)&in, &out_avail,

        &out, NULL);

    if (result == BROTLI_DECODER_RESULT_ERROR

        || in_avail != 0

        || BrotliDecoderHasMoreOutput(state->decoder))

        return -1;

    if (out_avail > olen)

        return -1;

    return (ossl_ssize_t)(olen - out_avail);

}

static COMP_METHOD brotli_stateful_method = {

    NID_brotli,

    LN_brotli,

    brotli_stateful_init,

    brotli_stateful_finish,

    brotli_stateful_compress_block,

    brotli_stateful_expand_block

};

static int brotli_oneshot_init(COMP_CTX *ctx)

{

    return 1;

}

static void brotli_oneshot_finish(COMP_CTX *ctx)

{

}

static ossl_ssize_t brotli_oneshot_compress_block(COMP_CTX *ctx, unsigned char *out,

    size_t olen, unsigned char *in,

    size_t ilen)

{

    size_t out_size = olen;

    ossl_ssize_t ret;

    if (ilen == 0)

        return 0;

    if (BrotliEncoderCompress(BROTLI_DEFAULT_QUALITY, BROTLI_DEFAULT_WINDOW,

            BROTLI_DEFAULT_MODE, ilen, in,

            &out_size, out)

        == BROTLI_FALSE)

        return -1;

    if (out_size > OSSL_SSIZE_MAX)

        return -1;

    ret = (ossl_ssize_t)out_size;

    if (ret < 0)

        return -1;

    return ret;

}

static ossl_ssize_t brotli_oneshot_expand_block(COMP_CTX *ctx, unsigned char *out,

    size_t olen, unsigned char *in,

    size_t ilen)

{

    size_t out_size = olen;

    ossl_ssize_t ret;

    if (ilen == 0)

        return 0;

    if (BrotliDecoderDecompress(ilen, in, &out_size, out) != BROTLI_DECODER_RESULT_SUCCESS)

        return -1;

    if (out_size > OSSL_SSIZE_MAX)

        return -1;

    ret = (ossl_ssize_t)out_size;

    if (ret < 0)

        return -1;

    return ret;

}

static COMP_METHOD brotli_oneshot_method = {

    NID_brotli,

    LN_brotli,

    brotli_oneshot_init,

    brotli_oneshot_finish,

    brotli_oneshot_compress_block,

    brotli_oneshot_expand_block

};

static CRYPTO_ONCE brotli_once = CRYPTO_ONCE_STATIC_INIT;

DEFINE_RUN_ONCE_STATIC(ossl_comp_brotli_init)

{

#ifdef BROTLI_SHARED

#if defined(OPENSSL_SYS_WINDOWS) || defined(OPENSSL_SYS_WIN32)

#define LIBBROTLIENC "BROTLIENC"

#define LIBBROTLIDEC "BROTLIDEC"

#else

#define LIBBROTLIENC "brotlienc"

#define LIBBROTLIDEC "brotlidec"

#endif

    ERR_set_mark();

    brotli_encode_dso = DSO_load(NULL, LIBBROTLIENC, NULL, 0);

    if (brotli_encode_dso != NULL) {

        p_encode_init = (encode_init_ft)DSO_bind_func(brotli_encode_dso, "BrotliEncoderCreateInstance");

        p_encode_stream = (encode_stream_ft)DSO_bind_func(brotli_encode_dso, "BrotliEncoderCompressStream");

        p_encode_has_more = (encode_has_more_ft)DSO_bind_func(brotli_encode_dso, "BrotliEncoderHasMoreOutput");

        p_encode_end = (encode_end_ft)DSO_bind_func(brotli_encode_dso, "BrotliEncoderDestroyInstance");

        p_encode_oneshot = (encode_oneshot_ft)DSO_bind_func(brotli_encode_dso, "BrotliEncoderCompress");

    }

    brotli_decode_dso = DSO_load(NULL, LIBBROTLIDEC, NULL, 0);

    if (brotli_decode_dso != NULL) {

        p_decode_init = (decode_init_ft)DSO_bind_func(brotli_decode_dso, "BrotliDecoderCreateInstance");

        p_decode_stream = (decode_stream_ft)DSO_bind_func(brotli_decode_dso, "BrotliDecoderDecompressStream");

        p_decode_has_more = (decode_has_more_ft)DSO_bind_func(brotli_decode_dso, "BrotliDecoderHasMoreOutput");

        p_decode_end = (decode_end_ft)DSO_bind_func(brotli_decode_dso, "BrotliDecoderDestroyInstance");

        p_decode_error = (decode_error_ft)DSO_bind_func(brotli_decode_dso, "BrotliDecoderGetErrorCode");

        p_decode_error_string = (decode_error_string_ft)DSO_bind_func(brotli_decode_dso, "BrotliDecoderErrorString");

        p_decode_is_finished = (decode_is_finished_ft)DSO_bind_func(brotli_decode_dso, "BrotliDecoderIsFinished");

        p_decode_oneshot = (decode_oneshot_ft)DSO_bind_func(brotli_decode_dso, "BrotliDecoderDecompress");

    }

    if (p_encode_init == NULL || p_encode_stream == NULL || p_encode_has_more == NULL

        || p_encode_end == NULL || p_encode_oneshot == NULL || p_decode_init == NULL

        || p_decode_stream == NULL || p_decode_has_more == NULL || p_decode_end == NULL

        || p_decode_error == NULL || p_decode_error_string == NULL || p_decode_is_finished == NULL

        || p_decode_oneshot == NULL) {

        ERR_clear_last_mark();

        ossl_comp_brotli_cleanup();

        return 0;

    }

    /* Do not leave errors behind on success. */

    ERR_pop_to_mark();

#endif

    return 1;

}

#endif /* ifndef BROTLI / else */

COMP_METHOD *COMP_brotli(void)

{

    COMP_METHOD *meth = NULL;

#ifndef OPENSSL_NO_BROTLI

    if (RUN_ONCE(&brotli_once, ossl_comp_brotli_init))

        meth = &brotli_stateful_method;

#endif

    return meth;

}

COMP_METHOD *COMP_brotli_oneshot(void)

{

    COMP_METHOD *meth = NULL;

#ifndef OPENSSL_NO_BROTLI

    if (RUN_ONCE(&brotli_once, ossl_comp_brotli_init))

        meth = &brotli_oneshot_method;

#endif

    return meth;

}

/* Also called from OPENSSL_cleanup() */

void ossl_comp_brotli_cleanup(void)

{

#ifdef BROTLI_SHARED

    DSO_free(brotli_encode_dso);

    brotli_encode_dso = NULL;

    DSO_free(brotli_decode_dso);

    brotli_decode_dso = NULL;

    p_encode_init = NULL;

    p_encode_stream = NULL;

    p_encode_has_more = NULL;

    p_encode_end = NULL;

    p_encode_oneshot = NULL;

    p_decode_init = NULL;

    p_decode_stream = NULL;

    p_decode_has_more = NULL;

    p_decode_end = NULL;

    p_decode_error = NULL;

    p_decode_error_string = NULL;

    p_decode_is_finished = NULL;

    p_decode_oneshot = NULL;

#endif

}

#ifndef OPENSSL_NO_BROTLI

/* Brotli-based compression/decompression filter BIO */

typedef struct {

    struct { /* input structure */

        size_t avail_in;

        unsigned char *next_in;

        size_t avail_out;

        unsigned char *next_out;

        unsigned char *buf;

        size_t bufsize;

        BrotliDecoderState *state;

    } decode;

    struct { /* output structure */

        size_t avail_in;

        unsigned char *next_in;

        size_t avail_out;

        unsigned char *next_out;

        unsigned char *buf;

        size_t bufsize;

        BrotliEncoderState *state;

        int mode; /* Encoder mode to use */

        int done;

        unsigned char *ptr;

        size_t count;

    } encode;

} BIO_BROTLI_CTX;

#define BROTLI_DEFAULT_BUFSIZE 1024

static int bio_brotli_new(BIO *bi);

static int bio_brotli_free(BIO *bi);

static int bio_brotli_read(BIO *b, char *out, int outl);

static int bio_brotli_write(BIO *b, const char *in, int inl);

static long bio_brotli_ctrl(BIO *b, int cmd, long num, void *ptr);

static long bio_brotli_callback_ctrl(BIO *b, int cmd, BIO_info_cb *fp);

static const BIO_METHOD bio_meth_brotli = {

    BIO_TYPE_COMP,

    "brotli",

    /* TODO: Convert to new style write function */

    bwrite_conv,

    bio_brotli_write,

    /* TODO: Convert to new style read function */

    bread_conv,

    bio_brotli_read,

    NULL, /* bio_brotli_puts, */

    NULL, /* bio_brotli_gets, */

    bio_brotli_ctrl,

    bio_brotli_new,

    bio_brotli_free,

    bio_brotli_callback_ctrl

};

#endif

const BIO_METHOD *BIO_f_brotli(void)

{

#ifndef OPENSSL_NO_BROTLI

    if (RUN_ONCE(&brotli_once, ossl_comp_brotli_init))

        return &bio_meth_brotli;

#endif

    return NULL;

}

#ifndef OPENSSL_NO_BROTLI

static int bio_brotli_new(BIO *bi)

{

    BIO_BROTLI_CTX *ctx;

#ifdef BROTLI_SHARED

    if (!RUN_ONCE(&brotli_once, ossl_comp_brotli_init)) {

        ERR_raise(ERR_LIB_COMP, COMP_R_BROTLI_NOT_SUPPORTED);

        return 0;

    }

#endif

    ctx = OPENSSL_zalloc(sizeof(*ctx));

    if (ctx == NULL) {

        ERR_raise(ERR_LIB_COMP, ERR_R_MALLOC_FAILURE);

        return 0;

    }

    ctx->decode.bufsize = BROTLI_DEFAULT_BUFSIZE;

    ctx->decode.state = BrotliDecoderCreateInstance(brotli_alloc, brotli_free, NULL);

    if (ctx->decode.state == NULL)

        goto err;

    ctx->encode.bufsize = BROTLI_DEFAULT_BUFSIZE;

    ctx->encode.state = BrotliEncoderCreateInstance(brotli_alloc, brotli_free, NULL);

    if (ctx->encode.state == NULL)

        goto err;

    ctx->encode.mode = BROTLI_DEFAULT_MODE;

    BIO_set_init(bi, 1);

    BIO_set_data(bi, ctx);

    return 1;

err:

    ERR_raise(ERR_LIB_COMP, ERR_R_MALLOC_FAILURE);

    BrotliDecoderDestroyInstance(ctx->decode.state);

    BrotliEncoderDestroyInstance(ctx->encode.state);

    OPENSSL_free(ctx);

    return 0;

}

static int bio_brotli_free(BIO *bi)

{

    BIO_BROTLI_CTX *ctx;

    if (bi == NULL)

        return 0;

    ctx = BIO_get_data(bi);

    if (ctx != NULL) {

        BrotliDecoderDestroyInstance(ctx->decode.state);

        OPENSSL_free(ctx->decode.buf);

        BrotliEncoderDestroyInstance(ctx->encode.state);

        OPENSSL_free(ctx->encode.buf);

        OPENSSL_free(ctx);

    }

    BIO_set_data(bi, NULL);

    BIO_set_init(bi, 0);

    return 1;

}

static int bio_brotli_read(BIO *b, char *out, int outl)

{

    BIO_BROTLI_CTX *ctx;

    BrotliDecoderResult bret;

    int ret;

    BIO *next = BIO_next(b);

    if (out == NULL || outl <= 0) {

        ERR_raise(ERR_LIB_COMP, ERR_R_PASSED_INVALID_ARGUMENT);

        return 0;

    }

#if INT_MAX > SIZE_MAX

    if ((unsigned int)outl > SIZE_MAX) {

        ERR_raise(ERR_LIB_COMP, ERR_R_PASSED_INVALID_ARGUMENT);

        return 0;

    }

#endif

    ctx = BIO_get_data(b);

    BIO_clear_retry_flags(b);

    if (ctx->decode.buf == NULL) {

        ctx->decode.buf = OPENSSL_malloc(ctx->decode.bufsize);

        if (ctx->decode.buf == NULL) {

            ERR_raise(ERR_LIB_COMP, ERR_R_MALLOC_FAILURE);

            return 0;

        }

        ctx->decode.next_in = ctx->decode.buf;

        ctx->decode.avail_in = 0;

    }

    /* Copy output data directly to supplied buffer */

    ctx->decode.next_out = (unsigned char *)out;

    ctx->decode.avail_out = (size_t)outl;

    for (;;) {

        /* Decompress while data available */

        while (ctx->decode.avail_in > 0 || BrotliDecoderHasMoreOutput(ctx->decode.state)) {

            bret = BrotliDecoderDecompressStream(ctx->decode.state, &ctx->decode.avail_in, (const uint8_t **)&ctx->decode.next_in,

                &ctx->decode.avail_out, &ctx->decode.next_out, NULL);

            if (bret == BROTLI_DECODER_RESULT_ERROR) {

                ERR_raise(ERR_LIB_COMP, COMP_R_BROTLI_DECODE_ERROR);

                ERR_add_error_data(1, BrotliDecoderErrorString(BrotliDecoderGetErrorCode(ctx->decode.state)));

                return 0;

            }

            /* If EOF or we've read everything then return */

            if (BrotliDecoderIsFinished(ctx->decode.state) || ctx->decode.avail_out == 0)

                return (int)(outl - ctx->decode.avail_out);

        }

        /* If EOF */

        if (BrotliDecoderIsFinished(ctx->decode.state))

            return 0;

        /*

         * No data in input buffer try to read some in, if an error then

         * return the total data read.

         */

        ret = BIO_read(next, ctx->decode.buf, ctx->decode.bufsize);

        if (ret <= 0) {

            /* Total data read */

            int tot = outl - ctx->decode.avail_out;

            BIO_copy_next_retry(b);

            if (ret < 0)

                return (tot > 0) ? tot : ret;

            return tot;

        }

        ctx->decode.avail_in = ret;

        ctx->decode.next_in = ctx->decode.buf;

    }

}

static int bio_brotli_write(BIO *b, const char *in, int inl)

{

    BIO_BROTLI_CTX *ctx;

    BROTLI_BOOL brret;

    int ret;

    BIO *next = BIO_next(b);

    if (in == NULL || inl <= 0) {

        ERR_raise(ERR_LIB_COMP, ERR_R_PASSED_INVALID_ARGUMENT);

        return 0;

    }

#if INT_MAX > SIZE_MAX

    if ((unsigned int)inl > SIZE_MAX) {

        ERR_raise(ERR_LIB_COMP, ERR_R_PASSED_INVALID_ARGUMENT);

        return 0;

    }

#endif

    ctx = BIO_get_data(b);

    if (ctx->encode.done)

        return 0;

    BIO_clear_retry_flags(b);

    if (ctx->encode.buf == NULL) {

        ctx->encode.buf = OPENSSL_malloc(ctx->encode.bufsize);

        if (ctx->encode.buf == NULL) {

            ERR_raise(ERR_LIB_COMP, ERR_R_MALLOC_FAILURE);

            return 0;

        }

        ctx->encode.ptr = ctx->encode.buf;

        ctx->encode.count = 0;

        ctx->encode.next_out = ctx->encode.buf;

        ctx->encode.avail_out = ctx->encode.bufsize;

    }

    /* Obtain input data directly from supplied buffer */

    ctx->encode.next_in = (unsigned char *)in;

    ctx->encode.avail_in = (size_t)inl;

    for (;;) {

        /* If data in output buffer write it first */

        while (ctx->encode.count > 0) {

            ret = BIO_write(next, ctx->encode.ptr, ctx->encode.count);

            if (ret <= 0) {

                /* Total data written */

                int tot = inl - ctx->encode.avail_in;

                BIO_copy_next_retry(b);

                if (ret < 0)

                    return (tot > 0) ? tot : ret;

                return tot;

            }

            ctx->encode.ptr += ret;

            ctx->encode.count -= ret;

        }

        /* Have we consumed all supplied data? */

        if (ctx->encode.avail_in == 0 && !BrotliEncoderHasMoreOutput(ctx->encode.state))

            return inl;

        /* Compress some more */

        /* Reset buffer */

        ctx->encode.ptr = ctx->encode.buf;

        ctx->encode.next_out = ctx->encode.buf;

        ctx->encode.avail_out = ctx->encode.bufsize;

        /* Compress some more */

        brret = BrotliEncoderCompressStream(ctx->encode.state, BROTLI_OPERATION_FLUSH, &ctx->encode.avail_in, (const uint8_t **)&ctx->encode.next_in,

            &ctx->encode.avail_out, &ctx->encode.next_out, NULL);

        if (brret != BROTLI_TRUE) {

            ERR_raise(ERR_LIB_COMP, COMP_R_BROTLI_ENCODE_ERROR);

            ERR_add_error_data(1, "brotli encoder error");

            return 0;

        }

        ctx->encode.count = ctx->encode.bufsize - ctx->encode.avail_out;

    }

}

static int bio_brotli_flush(BIO *b)

{

    BIO_BROTLI_CTX *ctx;

    BROTLI_BOOL brret;

    int ret;

    BIO *next = BIO_next(b);

    ctx = BIO_get_data(b);

    /* If no data written or already flush show success */

    if (ctx->encode.buf == NULL || (ctx->encode.done && ctx->encode.count == 0))

        return 1;

    BIO_clear_retry_flags(b);

    /* No more input data */

    ctx->encode.next_in = NULL;

    ctx->encode.avail_in = 0;

    for (;;) {

        /* If data in output buffer write it first */

        while (ctx->encode.count > 0) {

            ret = BIO_write(next, ctx->encode.ptr, ctx->encode.count);

            if (ret <= 0) {

                BIO_copy_next_retry(b);

                return ret;

            }

            ctx->encode.ptr += ret;

            ctx->encode.count -= ret;

        }

        if (ctx->encode.done)

            return 1;

        /* Compress some more */

        /* Reset buffer */

        ctx->encode.ptr = ctx->encode.buf;

        ctx->encode.next_out = ctx->encode.buf;

        ctx->encode.avail_out = ctx->encode.bufsize;

        /* Compress some more */

        brret = BrotliEncoderCompressStream(ctx->encode.state, BROTLI_OPERATION_FINISH, &ctx->encode.avail_in,

            (const uint8_t **)&ctx->encode.next_in, &ctx->encode.avail_out, &ctx->encode.next_out, NULL);

        if (brret != BROTLI_TRUE) {

            ERR_raise(ERR_LIB_COMP, COMP_R_BROTLI_ENCODE_ERROR);

            ERR_add_error_data(1, "brotli encoder error");

            return 0;

        }

        if (!BrotliEncoderHasMoreOutput(ctx->encode.state) && ctx->encode.avail_in == 0)

            ctx->encode.done = 1;

        ctx->encode.count = ctx->encode.bufsize - ctx->encode.avail_out;

    }

}

static long bio_brotli_ctrl(BIO *b, int cmd, long num, void *ptr)

{

    BIO_BROTLI_CTX *ctx;

    unsigned char *tmp;

    int ret = 0, *ip;

    size_t ibs, obs;

    BIO *next = BIO_next(b);

    if (next == NULL)

        return 0;

    ctx = BIO_get_data(b);

    switch (cmd) {

    case BIO_CTRL_RESET:

        ctx->encode.count = 0;

        ctx->encode.done = 0;

        ret = 1;

        break;

    case BIO_CTRL_FLUSH:

        ret = bio_brotli_flush(b);

        if (ret > 0) {

            ret = BIO_flush(next);

            BIO_copy_next_retry(b);

        }

        break;

    case BIO_C_SET_BUFF_SIZE:

        ibs = ctx->decode.bufsize;

        obs = ctx->encode.bufsize;

        if (ptr != NULL) {

            ip = ptr;

            if (*ip == 0)

                ibs = (size_t)num;

            else

                obs = (size_t)num;

        } else {

            ibs = (size_t)num;

            obs = ibs;

        }

        if (ibs > 0 && ibs != ctx->decode.bufsize) {

            /* Do not free/alloc, only reallocate */

            if (ctx->decode.buf != NULL) {

                tmp = OPENSSL_realloc(ctx->decode.buf, ibs);

                if (tmp == NULL)

                    return 0;

                ctx->decode.buf = tmp;

            }

            ctx->decode.bufsize = ibs;

        }

        if (obs > 0 && obs != ctx->encode.bufsize) {

            /* Do not free/alloc, only reallocate */

            if (ctx->encode.buf != NULL) {

                tmp = OPENSSL_realloc(ctx->encode.buf, obs);

                if (tmp == NULL)

                    return 0;

                ctx->encode.buf = tmp;

            }

            ctx->encode.bufsize = obs;

        }

        ret = 1;

        break;

    case BIO_C_DO_STATE_MACHINE:

        BIO_clear_retry_flags(b);

        ret = BIO_ctrl(next, cmd, num, ptr);

        BIO_copy_next_retry(b);

        break;

    case BIO_CTRL_WPENDING:

        if (BrotliEncoderHasMoreOutput(ctx->encode.state))

            ret = 1;

        else

            ret = BIO_ctrl(next, cmd, num, ptr);

        break;

    case BIO_CTRL_PENDING:

        if (!BrotliDecoderIsFinished(ctx->decode.state))

            ret = 1;

        else

            ret = BIO_ctrl(next, cmd, num, ptr);

        break;

    default:

        ret = BIO_ctrl(next, cmd, num, ptr);

        break;

    }

    return ret;

}

static long bio_brotli_callback_ctrl(BIO *b, int cmd, BIO_info_cb *fp)

{

    BIO *next = BIO_next(b);

    if (next == NULL)

        return 0;

    return BIO_callback_ctrl(next, cmd, fp);

}

#endif