text: /*
   * Copyright 1998-2016 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 <stdlib.h>
  #include <string.h>
  #include <openssl/objects.h>
  #include "internal/comp.h"
  #include <openssl/err.h>
  #include "internal/cryptlib_int.h"
  #include "internal/bio.h"
  #include "comp_lcl.h"
  
  COMP_METHOD *COMP_zlib(void);
  
  static COMP_METHOD zlib_method_nozlib = {
      NID_undef,
      "(undef)",
      NULL,
      NULL,
      NULL,
      NULL,
  };
  
  #ifndef ZLIB
  # undef ZLIB_SHARED
  #else
  
  # include <zlib.h>
  
  static int zlib_stateful_init(COMP_CTX *ctx);
  static void zlib_stateful_finish(COMP_CTX *ctx);
  static int zlib_stateful_compress_block(COMP_CTX *ctx, unsigned char *out,
                                          unsigned int olen, unsigned char *in,
                                          unsigned int ilen);
  static int zlib_stateful_expand_block(COMP_CTX *ctx, unsigned char *out,
                                        unsigned int olen, unsigned char *in,
                                        unsigned int ilen);
  
  /* memory allocations functions for zlib initialisation */
  static void *zlib_zalloc(void *opaque, unsigned int no, unsigned int size)
  {
      void *p;
  
      p = OPENSSL_zalloc(no * size);
      return p;
  }
  
  static void zlib_zfree(void *opaque, void *address)
  {
      OPENSSL_free(address);
  }
  
  
  static COMP_METHOD zlib_stateful_method = {
      NID_zlib_compression,
      LN_zlib_compression,
      zlib_stateful_init,
      zlib_stateful_finish,
      zlib_stateful_compress_block,
      zlib_stateful_expand_block
  };
  
  /*
   * When OpenSSL is built on Windows, we do not want to require that
   * the ZLIB.DLL be available in order for the OpenSSL DLLs to
   * work.  Therefore, all ZLIB routines are loaded at run time
   * and we do not link to a .LIB file when ZLIB_SHARED is set.
   */
  # if defined(OPENSSL_SYS_WINDOWS) || defined(OPENSSL_SYS_WIN32)
  #  include <windows.h>
  # endif                         /* !(OPENSSL_SYS_WINDOWS ||
                                   * OPENSSL_SYS_WIN32) */
  
  # ifdef ZLIB_SHARED
  #  include "internal/dso.h"
  
  /* Function pointers */
  typedef int (*compress_ft) (Bytef *dest, uLongf * destLen,
                              const Bytef *source, uLong sourceLen);
  typedef int (*inflateEnd_ft) (z_streamp strm);
  typedef int (*inflate_ft) (z_streamp strm, int flush);
  typedef int (*inflateInit__ft) (z_streamp strm,
                                  const char *version, int stream_size);
  typedef int (*deflateEnd_ft) (z_streamp strm);
  typedef int (*deflate_ft) (z_streamp strm, int flush);
  typedef int (*deflateInit__ft) (z_streamp strm, int level,
                                  const char *version, int stream_size);
  typedef const char *(*zError__ft) (int err);
  static compress_ft p_compress = NULL;
  static inflateEnd_ft p_inflateEnd = NULL;
  static inflate_ft p_inflate = NULL;
  static inflateInit__ft p_inflateInit_ = NULL;
  static deflateEnd_ft p_deflateEnd = NULL;
  static deflate_ft p_deflate = NULL;
  static deflateInit__ft p_deflateInit_ = NULL;
  static zError__ft p_zError = NULL;
  
  static int zlib_loaded = 0;     /* only attempt to init func pts once */
  static DSO *zlib_dso = NULL;
  
  #  define compress                p_compress
  #  define inflateEnd              p_inflateEnd
  #  define inflate                 p_inflate
  #  define inflateInit_            p_inflateInit_
  #  define deflateEnd              p_deflateEnd
  #  define deflate                 p_deflate
  #  define deflateInit_            p_deflateInit_
  #  define zError                  p_zError
  # endif                         /* ZLIB_SHARED */
  
  struct zlib_state {
      z_stream istream;
      z_stream ostream;
  };
  
  static int zlib_stateful_init(COMP_CTX *ctx)
  {
      int err;
      struct zlib_state *state = OPENSSL_zalloc(sizeof(*state));
  
      if (state == NULL)
          goto err;
  
      state->istream.zalloc = zlib_zalloc;
      state->istream.zfree = zlib_zfree;
      state->istream.opaque = Z_NULL;
      state->istream.next_in = Z_NULL;
      state->istream.next_out = Z_NULL;
      err = inflateInit_(&state->istream, ZLIB_VERSION, sizeof(z_stream));
      if (err != Z_OK)
          goto err;
  
      state->ostream.zalloc = zlib_zalloc;
      state->ostream.zfree = zlib_zfree;
      state->ostream.opaque = Z_NULL;
      state->ostream.next_in = Z_NULL;
      state->ostream.next_out = Z_NULL;
      err = deflateInit_(&state->ostream, Z_DEFAULT_COMPRESSION,
                         ZLIB_VERSION, sizeof(z_stream));
      if (err != Z_OK)
          goto err;
  
      ctx->data = state;
      return 1;
   err:
      OPENSSL_free(state);
      return 0;
  }
  
  static void zlib_stateful_finish(COMP_CTX *ctx)
  {
      struct zlib_state *state = ctx->data;
      inflateEnd(&state->istream);
      deflateEnd(&state->ostream);
      OPENSSL_free(state);
  }
  
  static int zlib_stateful_compress_block(COMP_CTX *ctx, unsigned char *out,
                                          unsigned int olen, unsigned char *in,
                                          unsigned int ilen)
  {
      int err = Z_OK;
      struct zlib_state *state = ctx->data;
  
      if (state == NULL)
          return -1;
  
      state->ostream.next_in = in;
      state->ostream.avail_in = ilen;
      state->ostream.next_out = out;
      state->ostream.avail_out = olen;
      if (ilen > 0)
          err = deflate(&state->ostream, Z_SYNC_FLUSH);
      if (err != Z_OK)
          return -1;
      return olen - state->ostream.avail_out;
  }
  
  static int zlib_stateful_expand_block(COMP_CTX *ctx, unsigned char *out,
                                        unsigned int olen, unsigned char *in,
                                        unsigned int ilen)
  {
      int err = Z_OK;
      struct zlib_state *state = ctx->data;
  
      if (state == NULL)
          return 0;
  
      state->istream.next_in = in;
      state->istream.avail_in = ilen;
      state->istream.next_out = out;
      state->istream.avail_out = olen;
      if (ilen > 0)
          err = inflate(&state->istream, Z_SYNC_FLUSH);
      if (err != Z_OK)
          return -1;
      return olen - state->istream.avail_out;
  }
  
  #endif
  
  COMP_METHOD *COMP_zlib(void)
  {
      COMP_METHOD *meth = &zlib_method_nozlib;
  
  #ifdef ZLIB_SHARED
      /* LIBZ may be externally defined, and we should respect that value */
  # ifndef LIBZ
  #  if defined(OPENSSL_SYS_WINDOWS) || defined(OPENSSL_SYS_WIN32)
  #   define LIBZ "ZLIB1"
  #  elif defined(OPENSSL_SYS_VMS)
  #   define LIBZ "LIBZ"
  #  else
  #   define LIBZ "z"
  #  endif
  # endif
  
      if (!zlib_loaded) {
          zlib_dso = DSO_load(NULL, LIBZ, NULL, 0);
          if (zlib_dso != NULL) {
              p_compress = (compress_ft) DSO_bind_func(zlib_dso, "compress");
              p_inflateEnd
                  = (inflateEnd_ft) DSO_bind_func(zlib_dso, "inflateEnd");
              p_inflate = (inflate_ft) DSO_bind_func(zlib_dso, "inflate");
              p_inflateInit_
                  = (inflateInit__ft) DSO_bind_func(zlib_dso, "inflateInit_");
              p_deflateEnd
                  = (deflateEnd_ft) DSO_bind_func(zlib_dso, "deflateEnd");
              p_deflate = (deflate_ft) DSO_bind_func(zlib_dso, "deflate");
              p_deflateInit_
                  = (deflateInit__ft) DSO_bind_func(zlib_dso, "deflateInit_");
              p_zError = (zError__ft) DSO_bind_func(zlib_dso, "zError");
  
              if (p_compress && p_inflateEnd && p_inflate
                  && p_inflateInit_ && p_deflateEnd
                  && p_deflate && p_deflateInit_ && p_zError)
                  zlib_loaded++;
  
              if (!OPENSSL_init_crypto(OPENSSL_INIT_ZLIB, NULL)) {
                  comp_zlib_cleanup_int();
                  return meth;
              }
              if (zlib_loaded)
                  meth = &zlib_stateful_method;
          }
      }
  #endif
  #if defined(ZLIB)
      meth = &zlib_stateful_method;
  #endif
  
      return meth;
  }
  
  void comp_zlib_cleanup_int(void)
  {
  #ifdef ZLIB_SHARED
      DSO_free(zlib_dso);
      zlib_dso = NULL;
  #endif
  }
  
  #ifdef ZLIB
  
  /* Zlib based compression/decompression filter BIO */
  
  typedef struct {
      unsigned char *ibuf;        /* Input buffer */
      int ibufsize;               /* Buffer size */
      z_stream zin;               /* Input decompress context */
      unsigned char *obuf;        /* Output buffer */
      int obufsize;               /* Output buffer size */
      unsigned char *optr;        /* Position in output buffer */
      int ocount;                 /* Amount of data in output buffer */
      int odone;                  /* deflate EOF */
      int comp_level;             /* Compression level to use */
      z_stream zout;              /* Output compression context */
  } BIO_ZLIB_CTX;
  
  # define ZLIB_DEFAULT_BUFSIZE 1024
  
  static int bio_zlib_new(BIO *bi);
  static int bio_zlib_free(BIO *bi);
  static int bio_zlib_read(BIO *b, char *out, int outl);
  static int bio_zlib_write(BIO *b, const char *in, int inl);
  static long bio_zlib_ctrl(BIO *b, int cmd, long num, void *ptr);
  static long bio_zlib_callback_ctrl(BIO *b, int cmd, BIO_info_cb *fp);
  
  static const BIO_METHOD bio_meth_zlib = {
      BIO_TYPE_COMP,
      "zlib",
      /* TODO: Convert to new style write function */
      bwrite_conv,
      bio_zlib_write,
      /* TODO: Convert to new style read function */
      bread_conv,
      bio_zlib_read,
      NULL,                      /* bio_zlib_puts, */
      NULL,                      /* bio_zlib_gets, */
      bio_zlib_ctrl,
      bio_zlib_new,
      bio_zlib_free,
      bio_zlib_callback_ctrl
  };
  
  const BIO_METHOD *BIO_f_zlib(void)
  {
      return &bio_meth_zlib;
  }
  
  static int bio_zlib_new(BIO *bi)
  {
      BIO_ZLIB_CTX *ctx;
  # ifdef ZLIB_SHARED
      (void)COMP_zlib();
      if (!zlib_loaded) {
          COMPerr(COMP_F_BIO_ZLIB_NEW, COMP_R_ZLIB_NOT_SUPPORTED);
          return 0;
      }
  # endif
      ctx = OPENSSL_zalloc(sizeof(*ctx));
      if (ctx == NULL) {
          COMPerr(COMP_F_BIO_ZLIB_NEW, ERR_R_MALLOC_FAILURE);
          return 0;
      }
      ctx->ibufsize = ZLIB_DEFAULT_BUFSIZE;
      ctx->obufsize = ZLIB_DEFAULT_BUFSIZE;
      ctx->zin.zalloc = Z_NULL;
      ctx->zin.zfree = Z_NULL;
      ctx->zout.zalloc = Z_NULL;
      ctx->zout.zfree = Z_NULL;
      ctx->comp_level = Z_DEFAULT_COMPRESSION;
      BIO_set_init(bi, 1);
      BIO_set_data(bi, ctx);
  
      return 1;
  }
  
  static int bio_zlib_free(BIO *bi)
  {
      BIO_ZLIB_CTX *ctx;
      if (!bi)
          return 0;
      ctx = BIO_get_data(bi);
      if (ctx->ibuf) {
          /* Destroy decompress context */
          inflateEnd(&ctx->zin);
          OPENSSL_free(ctx->ibuf);
      }
      if (ctx->obuf) {
          /* Destroy compress context */
          deflateEnd(&ctx->zout);
          OPENSSL_free(ctx->obuf);
      }
      OPENSSL_free(ctx);
      BIO_set_data(bi, NULL);
      BIO_set_init(bi, 0);
  
      return 1;
  }
  
  static int bio_zlib_read(BIO *b, char *out, int outl)
  {
      BIO_ZLIB_CTX *ctx;
      int ret;
      z_stream *zin;
      BIO *next = BIO_next(b);
  
      if (!out || !outl)
          return 0;
      ctx = BIO_get_data(b);
      zin = &ctx->zin;
      BIO_clear_retry_flags(b);
      if (!ctx->ibuf) {
          ctx->ibuf = OPENSSL_malloc(ctx->ibufsize);
          if (ctx->ibuf == NULL) {
              COMPerr(COMP_F_BIO_ZLIB_READ, ERR_R_MALLOC_FAILURE);
              return 0;
          }
          inflateInit(zin);
          zin->next_in = ctx->ibuf;
          zin->avail_in = 0;
      }
  
      /* Copy output data directly to supplied buffer */
      zin->next_out = (unsigned char *)out;
      zin->avail_out = (unsigned int)outl;
      for (;;) {
          /* Decompress while data available */
          while (zin->avail_in) {
              ret = inflate(zin, 0);
              if ((ret != Z_OK) && (ret != Z_STREAM_END)) {
                  COMPerr(COMP_F_BIO_ZLIB_READ, COMP_R_ZLIB_INFLATE_ERROR);
                  ERR_add_error_data(2, "zlib error:", zError(ret));
                  return 0;
              }
              /* If EOF or we've read everything then return */
              if ((ret == Z_STREAM_END) || !zin->avail_out)
                  return outl - zin->avail_out;
          }
  
          /*
           * No data in input buffer try to read some in, if an error then
           * return the total data read.
           */
          ret = BIO_read(next, ctx->ibuf, ctx->ibufsize);
          if (ret <= 0) {
              /* Total data read */
              int tot = outl - zin->avail_out;
              BIO_copy_next_retry(b);
              if (ret < 0)
                  return (tot > 0) ? tot : ret;
              return tot;
          }
          zin->avail_in = ret;
          zin->next_in = ctx->ibuf;
      }
  }
  
  static int bio_zlib_write(BIO *b, const char *in, int inl)
  {
      BIO_ZLIB_CTX *ctx;
      int ret;
      z_stream *zout;
      BIO *next = BIO_next(b);
  
      if (!in || !inl)
          return 0;
      ctx = BIO_get_data(b);
      if (ctx->odone)
          return 0;
      zout = &ctx->zout;
      BIO_clear_retry_flags(b);
      if (!ctx->obuf) {
          ctx->obuf = OPENSSL_malloc(ctx->obufsize);
          /* Need error here */
          if (ctx->obuf == NULL) {
              COMPerr(COMP_F_BIO_ZLIB_WRITE, ERR_R_MALLOC_FAILURE);
              return 0;
          }
          ctx->optr = ctx->obuf;
          ctx->ocount = 0;
          deflateInit(zout, ctx->comp_level);
          zout->next_out = ctx->obuf;
          zout->avail_out = ctx->obufsize;
      }
      /* Obtain input data directly from supplied buffer */
      zout->next_in = (void *)in;
      zout->avail_in = inl;
      for (;;) {
          /* If data in output buffer write it first */
          while (ctx->ocount) {
              ret = BIO_write(next, ctx->optr, ctx->ocount);
              if (ret <= 0) {
                  /* Total data written */
                  int tot = inl - zout->avail_in;
                  BIO_copy_next_retry(b);
                  if (ret < 0)
                      return (tot > 0) ? tot : ret;
                  return tot;
              }
              ctx->optr += ret;
              ctx->ocount -= ret;
          }
  
          /* Have we consumed all supplied data? */
          if (!zout->avail_in)
              return inl;
  
          /* Compress some more */
  
          /* Reset buffer */
          ctx->optr = ctx->obuf;
          zout->next_out = ctx->obuf;
          zout->avail_out = ctx->obufsize;
          /* Compress some more */
          ret = deflate(zout, 0);
          if (ret != Z_OK) {
              COMPerr(COMP_F_BIO_ZLIB_WRITE, COMP_R_ZLIB_DEFLATE_ERROR);
              ERR_add_error_data(2, "zlib error:", zError(ret));
              return 0;
          }
          ctx->ocount = ctx->obufsize - zout->avail_out;
      }
  }
  
  static int bio_zlib_flush(BIO *b)
  {
      BIO_ZLIB_CTX *ctx;
      int ret;
      z_stream *zout;
      BIO *next = BIO_next(b);
  
      ctx = BIO_get_data(b);
      /* If no data written or already flush show success */
      if (!ctx->obuf || (ctx->odone && !ctx->ocount))
          return 1;
      zout = &ctx->zout;
      BIO_clear_retry_flags(b);
      /* No more input data */
      zout->next_in = NULL;
      zout->avail_in = 0;
      for (;;) {
          /* If data in output buffer write it first */
          while (ctx->ocount) {
              ret = BIO_write(next, ctx->optr, ctx->ocount);
              if (ret <= 0) {
                  BIO_copy_next_retry(b);
                  return ret;
              }
              ctx->optr += ret;
              ctx->ocount -= ret;
          }
          if (ctx->odone)
              return 1;
  
          /* Compress some more */
  
          /* Reset buffer */
          ctx->optr = ctx->obuf;
          zout->next_out = ctx->obuf;
          zout->avail_out = ctx->obufsize;
          /* Compress some more */
          ret = deflate(zout, Z_FINISH);
          if (ret == Z_STREAM_END)
              ctx->odone = 1;
          else if (ret != Z_OK) {
              COMPerr(COMP_F_BIO_ZLIB_FLUSH, COMP_R_ZLIB_DEFLATE_ERROR);
              ERR_add_error_data(2, "zlib error:", zError(ret));
              return 0;
          }
          ctx->ocount = ctx->obufsize - zout->avail_out;
      }
  }
  
  static long bio_zlib_ctrl(BIO *b, int cmd, long num, void *ptr)
  {
      BIO_ZLIB_CTX *ctx;
      int ret, *ip;
      int ibs, obs;
      BIO *next = BIO_next(b);
  
      if (next == NULL)
          return 0;
      ctx = BIO_get_data(b);
      switch (cmd) {
  
      case BIO_CTRL_RESET:
          ctx->ocount = 0;
          ctx->odone = 0;
          ret = 1;
          break;
  
      case BIO_CTRL_FLUSH:
          ret = bio_zlib_flush(b);
          if (ret > 0)
              ret = BIO_flush(next);
          break;
  
      case BIO_C_SET_BUFF_SIZE:
          ibs = -1;
          obs = -1;
          if (ptr != NULL) {
              ip = ptr;
              if (*ip == 0)
                  ibs = (int)num;
              else
                  obs = (int)num;
          } else {
              ibs = (int)num;
              obs = ibs;
          }
  
          if (ibs != -1) {
              OPENSSL_free(ctx->ibuf);
              ctx->ibuf = NULL;
              ctx->ibufsize = ibs;
          }
  
          if (obs != -1) {
              OPENSSL_free(ctx->obuf);
              ctx->obuf = NULL;
              ctx->obufsize = 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;
  
      default:
          ret = BIO_ctrl(next, cmd, num, ptr);
          break;
  
      }
  
      return ret;
  }
  
  static long bio_zlib_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
  