text: /* crypto/evp/encode.c */
  /* 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 <stdio.h>
  #include "cryptlib.h"
  #include <openssl/evp.h>
  
  #ifndef CHARSET_EBCDIC
  # define conv_bin2ascii(a)       (data_bin2ascii[(a)&0x3f])
  # define conv_ascii2bin(a)       (data_ascii2bin[(a)&0x7f])
  #else
  /*
   * We assume that PEM encoded files are EBCDIC files (i.e., printable text
   * files). Convert them here while decoding. When encoding, output is EBCDIC
   * (text) format again. (No need for conversion in the conv_bin2ascii macro,
   * as the underlying textstring data_bin2ascii[] is already EBCDIC)
   */
  # define conv_bin2ascii(a)       (data_bin2ascii[(a)&0x3f])
  # define conv_ascii2bin(a)       (data_ascii2bin[os_toascii[a]&0x7f])
  #endif
  
  /*-
   * 64 char lines
   * pad input with 0
   * left over chars are set to =
   * 1 byte  => xx==
   * 2 bytes => xxx=
   * 3 bytes => xxxx
   */
  #define BIN_PER_LINE    (64/4*3)
  #define CHUNKS_PER_LINE (64/4)
  #define CHAR_PER_LINE   (64+1)
  
  static const unsigned char data_bin2ascii[65] = "ABCDEFGHIJKLMNOPQRSTUVWXYZ\
  abcdefghijklmnopqrstuvwxyz0123456789+/";
  
  /*-
   * 0xF0 is a EOLN
   * 0xF1 is ignore but next needs to be 0xF0 (for \r\n processing).
   * 0xF2 is EOF
   * 0xE0 is ignore at start of line.
   * 0xFF is error
   */
  
  #define B64_EOLN                0xF0
  #define B64_CR                  0xF1
  #define B64_EOF                 0xF2
  #define B64_WS                  0xE0
  #define B64_ERROR               0xFF
  #define B64_NOT_BASE64(a)       (((a)|0x13) == 0xF3)
  
  static const unsigned char data_ascii2bin[128] = {
      0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
      0xFF, 0xE0, 0xF0, 0xFF, 0xFF, 0xF1, 0xFF, 0xFF,
      0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
      0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
      0xE0, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
      0xFF, 0xFF, 0xFF, 0x3E, 0xFF, 0xF2, 0xFF, 0x3F,
      0x34, 0x35, 0x36, 0x37, 0x38, 0x39, 0x3A, 0x3B,
      0x3C, 0x3D, 0xFF, 0xFF, 0xFF, 0x00, 0xFF, 0xFF,
      0xFF, 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06,
      0x07, 0x08, 0x09, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E,
      0x0F, 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16,
      0x17, 0x18, 0x19, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
      0xFF, 0x1A, 0x1B, 0x1C, 0x1D, 0x1E, 0x1F, 0x20,
      0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27, 0x28,
      0x29, 0x2A, 0x2B, 0x2C, 0x2D, 0x2E, 0x2F, 0x30,
      0x31, 0x32, 0x33, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
  };
  
  void EVP_EncodeInit(EVP_ENCODE_CTX *ctx)
  {
      ctx->length = 48;
      ctx->num = 0;
      ctx->line_num = 0;
  }
  
  void EVP_EncodeUpdate(EVP_ENCODE_CTX *ctx, unsigned char *out, int *outl,
                        const unsigned char *in, int inl)
  {
      int i, j;
      unsigned int total = 0;
  
      *outl = 0;
      if (inl == 0)
          return;
      OPENSSL_assert(ctx->length <= (int)sizeof(ctx->enc_data));
      if ((ctx->num + inl) < ctx->length) {
          memcpy(&(ctx->enc_data[ctx->num]), in, inl);
          ctx->num += inl;
          return;
      }
      if (ctx->num != 0) {
          i = ctx->length - ctx->num;
          memcpy(&(ctx->enc_data[ctx->num]), in, i);
          in += i;
          inl -= i;
          j = EVP_EncodeBlock(out, ctx->enc_data, ctx->length);
          ctx->num = 0;
          out += j;
          *(out++) = '\n';
          *out = '\0';
          total = j + 1;
      }
      while (inl >= ctx->length) {
          j = EVP_EncodeBlock(out, in, ctx->length);
          in += ctx->length;
          inl -= ctx->length;
          out += j;
          *(out++) = '\n';
          *out = '\0';
          total += j + 1;
      }
      if (inl != 0)
          memcpy(&(ctx->enc_data[0]), in, inl);
      ctx->num = inl;
      *outl = total;
  }
  
  void EVP_EncodeFinal(EVP_ENCODE_CTX *ctx, unsigned char *out, int *outl)
  {
      unsigned int ret = 0;
  
      if (ctx->num != 0) {
          ret = EVP_EncodeBlock(out, ctx->enc_data, ctx->num);
          out[ret++] = '\n';
          out[ret] = '\0';
          ctx->num = 0;
      }
      *outl = ret;
  }
  
  int EVP_EncodeBlock(unsigned char *t, const unsigned char *f, int dlen)
  {
      int i, ret = 0;
      unsigned long l;
  
      for (i = dlen; i > 0; i -= 3) {
          if (i >= 3) {
              l = (((unsigned long)f[0]) << 16L) |
                  (((unsigned long)f[1]) << 8L) | f[2];
              *(t++) = conv_bin2ascii(l >> 18L);
              *(t++) = conv_bin2ascii(l >> 12L);
              *(t++) = conv_bin2ascii(l >> 6L);
              *(t++) = conv_bin2ascii(l);
          } else {
              l = ((unsigned long)f[0]) << 16L;
              if (i == 2)
                  l |= ((unsigned long)f[1] << 8L);
  
              *(t++) = conv_bin2ascii(l >> 18L);
              *(t++) = conv_bin2ascii(l >> 12L);
              *(t++) = (i == 1) ? '=' : conv_bin2ascii(l >> 6L);
              *(t++) = '=';
          }
          ret += 4;
          f += 3;
      }
  
      *t = '\0';
      return (ret);
  }
  
  void EVP_DecodeInit(EVP_ENCODE_CTX *ctx)
  {
      ctx->length = 30;
      ctx->num = 0;
      ctx->line_num = 0;
      ctx->expect_nl = 0;
  }
  
  /*-
   * -1 for error
   *  0 for last line
   *  1 for full line
   */
  int EVP_DecodeUpdate(EVP_ENCODE_CTX *ctx, unsigned char *out, int *outl,
                       const unsigned char *in, int inl)
  {
      int seof = -1, eof = 0, rv = -1, ret = 0, i, v, tmp, n, ln, exp_nl;
      unsigned char *d;
  
      n = ctx->num;
      d = ctx->enc_data;
      ln = ctx->line_num;
      exp_nl = ctx->expect_nl;
  
      /* last line of input. */
      if ((inl == 0) || ((n == 0) && (conv_ascii2bin(in[0]) == B64_EOF))) {
          rv = 0;
          goto end;
      }
  
      /* We parse the input data */
      for (i = 0; i < inl; i++) {
          /* If the current line is > 80 characters, scream alot */
          if (ln >= 80) {
              rv = -1;
              goto end;
          }
  
          /* Get char and put it into the buffer */
          tmp = *(in++);
          v = conv_ascii2bin(tmp);
          /* only save the good data :-) */
          if (!B64_NOT_BASE64(v)) {
              OPENSSL_assert(n < (int)sizeof(ctx->enc_data));
              d[n++] = tmp;
              ln++;
          } else if (v == B64_ERROR) {
              rv = -1;
              goto end;
          }
  
          /*
           * have we seen a '=' which is 'definitly' the last input line.  seof
           * will point to the character that holds it. and eof will hold how
           * many characters to chop off.
           */
          if (tmp == '=') {
              if (seof == -1)
                  seof = n;
              eof++;
          }
  
          if (v == B64_CR) {
              ln = 0;
              if (exp_nl)
                  continue;
          }
  
          /* eoln */
          if (v == B64_EOLN) {
              ln = 0;
              if (exp_nl) {
                  exp_nl = 0;
                  continue;
              }
          }
          exp_nl = 0;
  
          /*
           * If we are at the end of input and it looks like a line, process
           * it.
           */
          if (((i + 1) == inl) && (((n & 3) == 0) || eof)) {
              v = B64_EOF;
              /*
               * In case things were given us in really small records (so two
               * '=' were given in separate updates), eof may contain the
               * incorrect number of ending bytes to skip, so let's redo the
               * count
               */
              eof = 0;
              if (d[n - 1] == '=')
                  eof++;
              if (d[n - 2] == '=')
                  eof++;
              /* There will never be more than two '=' */
          }
  
          if ((v == B64_EOF && (n & 3) == 0) || (n >= 64)) {
              /*
               * This is needed to work correctly on 64 byte input lines.  We
               * process the line and then need to accept the '\n'
               */
              if ((v != B64_EOF) && (n >= 64))
                  exp_nl = 1;
              if (n > 0) {
                  v = EVP_DecodeBlock(out, d, n);
                  n = 0;
                  if (v < 0) {
                      rv = 0;
                      goto end;
                  }
                  if (eof > v) {
                      rv = -1;
                      goto end;
                  }
                  ret += (v - eof);
              } else {
                  eof = 1;
                  v = 0;
              }
  
              /*
               * This is the case where we have had a short but valid input
               * line
               */
              if ((v < ctx->length) && eof) {
                  rv = 0;
                  goto end;
              } else
                  ctx->length = v;
  
              if (seof >= 0) {
                  rv = 0;
                  goto end;
              }
              out += v;
          }
      }
      rv = 1;
   end:
      *outl = ret;
      ctx->num = n;
      ctx->line_num = ln;
      ctx->expect_nl = exp_nl;
      return (rv);
  }
  
  int EVP_DecodeBlock(unsigned char *t, const unsigned char *f, int n)
  {
      int i, ret = 0, a, b, c, d;
      unsigned long l;
  
      /* trim white space from the start of the line. */
      while ((conv_ascii2bin(*f) == B64_WS) && (n > 0)) {
          f++;
          n--;
      }
  
      /*
       * strip off stuff at the end of the line ascii2bin values B64_WS,
       * B64_EOLN, B64_EOLN and B64_EOF
       */
      while ((n > 3) && (B64_NOT_BASE64(conv_ascii2bin(f[n - 1]))))
          n--;
  
      if (n % 4 != 0)
          return (-1);
  
      for (i = 0; i < n; i += 4) {
          a = conv_ascii2bin(*(f++));
          b = conv_ascii2bin(*(f++));
          c = conv_ascii2bin(*(f++));
          d = conv_ascii2bin(*(f++));
          if ((a & 0x80) || (b & 0x80) || (c & 0x80) || (d & 0x80))
              return (-1);
          l = ((((unsigned long)a) << 18L) |
               (((unsigned long)b) << 12L) |
               (((unsigned long)c) << 6L) | (((unsigned long)d)));
          *(t++) = (unsigned char)(l >> 16L) & 0xff;
          *(t++) = (unsigned char)(l >> 8L) & 0xff;
          *(t++) = (unsigned char)(l) & 0xff;
          ret += 3;
      }
      return (ret);
  }
  
  int EVP_DecodeFinal(EVP_ENCODE_CTX *ctx, unsigned char *out, int *outl)
  {
      int i;
  
      *outl = 0;
      if (ctx->num != 0) {
          i = EVP_DecodeBlock(out, ctx->enc_data, ctx->num);
          if (i < 0)
              return (-1);
          ctx->num = 0;
          *outl = i;
          return (1);
      } else
          return (1);
  }
  
  #ifdef undef
  int EVP_DecodeValid(unsigned char *buf, int len)
  {
      int i, num = 0, bad = 0;
  
      if (len == 0)
          return (-1);
      while (conv_ascii2bin(*buf) == B64_WS) {
          buf++;
          len--;
          if (len == 0)
              return (-1);
      }
  
      for (i = len; i >= 4; i -= 4) {
          if ((conv_ascii2bin(buf[0]) >= 0x40) ||
              (conv_ascii2bin(buf[1]) >= 0x40) ||
              (conv_ascii2bin(buf[2]) >= 0x40) ||
              (conv_ascii2bin(buf[3]) >= 0x40))
              return (-1);
          buf += 4;
          num += 1 + (buf[2] != '=') + (buf[3] != '=');
      }
      if ((i == 1) && (conv_ascii2bin(buf[0]) == B64_EOLN))
          return (num);
      if ((i == 2) && (conv_ascii2bin(buf[0]) == B64_EOLN) &&
          (conv_ascii2bin(buf[0]) == B64_EOLN))
          return (num);
      return (1);
  }
  #endif
  