text: /*
   * Copyright 1995-2018 The OpenSSL Project Authors. All Rights Reserved.
   *
   * Licensed under the OpenSSL license (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 <errno.h>
  #include "bio_lcl.h"
  #include "internal/cryptlib.h"
  #include <openssl/evp.h>
  
  static int linebuffer_write(BIO *h, const char *buf, int num);
  static int linebuffer_read(BIO *h, char *buf, int size);
  static int linebuffer_puts(BIO *h, const char *str);
  static int linebuffer_gets(BIO *h, char *str, int size);
  static long linebuffer_ctrl(BIO *h, int cmd, long arg1, void *arg2);
  static int linebuffer_new(BIO *h);
  static int linebuffer_free(BIO *data);
  static long linebuffer_callback_ctrl(BIO *h, int cmd, BIO_info_cb *fp);
  
  /* A 10k maximum should be enough for most purposes */
  #define DEFAULT_LINEBUFFER_SIZE 1024*10
  
  /* #define DEBUG */
  
  static const BIO_METHOD methods_linebuffer = {
      BIO_TYPE_LINEBUFFER,
      "linebuffer",
      linebuffer_write,
      linebuffer_read,
      linebuffer_puts,
      linebuffer_gets,
      linebuffer_ctrl,
      linebuffer_new,
      linebuffer_free,
      linebuffer_callback_ctrl,
  };
  
  const BIO_METHOD *BIO_f_linebuffer(void)
  {
      return (&methods_linebuffer);
  }
  
  typedef struct bio_linebuffer_ctx_struct {
      char *obuf;                 /* the output char array */
      int obuf_size;              /* how big is the output buffer */
      int obuf_len;               /* how many bytes are in it */
  } BIO_LINEBUFFER_CTX;
  
  static int linebuffer_new(BIO *bi)
  {
      BIO_LINEBUFFER_CTX *ctx;
  
      ctx = OPENSSL_malloc(sizeof(*ctx));
      if (ctx == NULL)
          return (0);
      ctx->obuf = OPENSSL_malloc(DEFAULT_LINEBUFFER_SIZE);
      if (ctx->obuf == NULL) {
          OPENSSL_free(ctx);
          return (0);
      }
      ctx->obuf_size = DEFAULT_LINEBUFFER_SIZE;
      ctx->obuf_len = 0;
  
      bi->init = 1;
      bi->ptr = (char *)ctx;
      bi->flags = 0;
      return (1);
  }
  
  static int linebuffer_free(BIO *a)
  {
      BIO_LINEBUFFER_CTX *b;
  
      if (a == NULL)
          return (0);
      b = (BIO_LINEBUFFER_CTX *)a->ptr;
      OPENSSL_free(b->obuf);
      OPENSSL_free(a->ptr);
      a->ptr = NULL;
      a->init = 0;
      a->flags = 0;
      return (1);
  }
  
  static int linebuffer_read(BIO *b, char *out, int outl)
  {
      int ret = 0;
  
      if (out == NULL)
          return (0);
      if (b->next_bio == NULL)
          return (0);
      ret = BIO_read(b->next_bio, out, outl);
      BIO_clear_retry_flags(b);
      BIO_copy_next_retry(b);
      return (ret);
  }
  
  static int linebuffer_write(BIO *b, const char *in, int inl)
  {
      int i, num = 0, foundnl;
      BIO_LINEBUFFER_CTX *ctx;
  
      if ((in == NULL) || (inl <= 0))
          return (0);
      ctx = (BIO_LINEBUFFER_CTX *)b->ptr;
      if ((ctx == NULL) || (b->next_bio == NULL))
          return (0);
  
      BIO_clear_retry_flags(b);
  
      do {
          const char *p;
          char c;
  
          for (p = in, c = '\0'; p < in + inl && (c = *p) != '\n'; p++) ;
          if (c == '\n') {
              p++;
              foundnl = 1;
          } else
              foundnl = 0;
  
          /*
           * If a NL was found and we already have text in the save buffer,
           * concatenate them and write
           */
          while ((foundnl || p - in > ctx->obuf_size - ctx->obuf_len)
                 && ctx->obuf_len > 0) {
              int orig_olen = ctx->obuf_len;
  
              i = ctx->obuf_size - ctx->obuf_len;
              if (p - in > 0) {
                  if (i >= p - in) {
                      memcpy(&(ctx->obuf[ctx->obuf_len]), in, p - in);
                      ctx->obuf_len += p - in;
                      inl -= p - in;
                      num += p - in;
                      in = p;
                  } else {
                      memcpy(&(ctx->obuf[ctx->obuf_len]), in, i);
                      ctx->obuf_len += i;
                      inl -= i;
                      in += i;
                      num += i;
                  }
              }
              i = BIO_write(b->next_bio, ctx->obuf, ctx->obuf_len);
              if (i <= 0) {
                  ctx->obuf_len = orig_olen;
                  BIO_copy_next_retry(b);
  
                  if (i < 0)
                      return ((num > 0) ? num : i);
                  if (i == 0)
                      return (num);
              }
              if (i < ctx->obuf_len)
                  memmove(ctx->obuf, ctx->obuf + i, ctx->obuf_len - i);
              ctx->obuf_len -= i;
          }
  
          /*
           * Now that the save buffer is emptied, let's write the input buffer
           * if a NL was found and there is anything to write.
           */
          if ((foundnl || p - in > ctx->obuf_size) && p - in > 0) {
              i = BIO_write(b->next_bio, in, p - in);
              if (i <= 0) {
                  BIO_copy_next_retry(b);
                  if (i < 0)
                      return ((num > 0) ? num : i);
                  if (i == 0)
                      return (num);
              }
              num += i;
              in += i;
              inl -= i;
          }
      }
      while (foundnl && inl > 0);
      /*
       * We've written as much as we can.  The rest of the input buffer, if
       * any, is text that doesn't and with a NL and therefore needs to be
       * saved for the next trip.
       */
      if (inl > 0) {
          memcpy(&(ctx->obuf[ctx->obuf_len]), in, inl);
          ctx->obuf_len += inl;
          num += inl;
      }
      return num;
  }
  
  static long linebuffer_ctrl(BIO *b, int cmd, long num, void *ptr)
  {
      BIO *dbio;
      BIO_LINEBUFFER_CTX *ctx;
      long ret = 1;
      char *p;
      int r;
      int obs;
  
      ctx = (BIO_LINEBUFFER_CTX *)b->ptr;
  
      switch (cmd) {
      case BIO_CTRL_RESET:
          ctx->obuf_len = 0;
          if (b->next_bio == NULL)
              return (0);
          ret = BIO_ctrl(b->next_bio, cmd, num, ptr);
          break;
      case BIO_CTRL_INFO:
          ret = (long)ctx->obuf_len;
          break;
      case BIO_CTRL_WPENDING:
          ret = (long)ctx->obuf_len;
          if (ret == 0) {
              if (b->next_bio == NULL)
                  return (0);
              ret = BIO_ctrl(b->next_bio, cmd, num, ptr);
          }
          break;
      case BIO_C_SET_BUFF_SIZE:
          obs = (int)num;
          p = ctx->obuf;
          if ((obs > DEFAULT_LINEBUFFER_SIZE) && (obs != ctx->obuf_size)) {
              p = OPENSSL_malloc((int)num);
              if (p == NULL)
                  goto malloc_error;
          }
          if (ctx->obuf != p) {
              if (ctx->obuf_len > obs) {
                  ctx->obuf_len = obs;
              }
              memcpy(p, ctx->obuf, ctx->obuf_len);
              OPENSSL_free(ctx->obuf);
              ctx->obuf = p;
              ctx->obuf_size = obs;
          }
          break;
      case BIO_C_DO_STATE_MACHINE:
          if (b->next_bio == NULL)
              return (0);
          BIO_clear_retry_flags(b);
          ret = BIO_ctrl(b->next_bio, cmd, num, ptr);
          BIO_copy_next_retry(b);
          break;
  
      case BIO_CTRL_FLUSH:
          if (b->next_bio == NULL)
              return (0);
          if (ctx->obuf_len <= 0) {
              ret = BIO_ctrl(b->next_bio, cmd, num, ptr);
              break;
          }
  
          for (;;) {
              BIO_clear_retry_flags(b);
              if (ctx->obuf_len > 0) {
                  r = BIO_write(b->next_bio, ctx->obuf, ctx->obuf_len);
                  BIO_copy_next_retry(b);
                  if (r <= 0)
                      return ((long)r);
                  if (r < ctx->obuf_len)
                      memmove(ctx->obuf, ctx->obuf + r, ctx->obuf_len - r);
                  ctx->obuf_len -= r;
              } else {
                  ctx->obuf_len = 0;
                  break;
              }
          }
          ret = BIO_ctrl(b->next_bio, cmd, num, ptr);
          break;
      case BIO_CTRL_DUP:
          dbio = (BIO *)ptr;
          if (!BIO_set_write_buffer_size(dbio, ctx->obuf_size))
              ret = 0;
          break;
      default:
          if (b->next_bio == NULL)
              return (0);
          ret = BIO_ctrl(b->next_bio, cmd, num, ptr);
          break;
      }
      return (ret);
   malloc_error:
      BIOerr(BIO_F_LINEBUFFER_CTRL, ERR_R_MALLOC_FAILURE);
      return (0);
  }
  
  static long linebuffer_callback_ctrl(BIO *b, int cmd, BIO_info_cb *fp)
  {
      long ret = 1;
  
      if (b->next_bio == NULL)
          return (0);
      switch (cmd) {
      default:
          ret = BIO_callback_ctrl(b->next_bio, cmd, fp);
          break;
      }
      return (ret);
  }
  
  static int linebuffer_gets(BIO *b, char *buf, int size)
  {
      if (b->next_bio == NULL)
          return (0);
      return (BIO_gets(b->next_bio, buf, size));
  }
  
  static int linebuffer_puts(BIO *b, const char *str)
  {
      return (linebuffer_write(b, str, strlen(str)));
  }
  