userapps/opensource/sshd/libtomcrypt/base64.c

   1 /* compliant base64 code donated by Wayne Scott (wscott@bitmover.com) */
   2 #include "mycrypt.h"
   3
   4 #ifdef BASE64
   5
   6 static const char *codes =
   7 "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
   8
   9 static const unsigned char map[256] = {
  10 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
  11 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
  12 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
  13 255, 255, 255, 255, 255, 255, 255,  62, 255, 255, 255,  63,
  14  52,  53,  54,  55,  56,  57,  58,  59,  60,  61, 255, 255,
  15 255, 254, 255, 255, 255,   0,   1,   2,   3,   4,   5,   6,
  16   7,   8,   9,  10,  11,  12,  13,  14,  15,  16,  17,  18,
  17  19,  20,  21,  22,  23,  24,  25, 255, 255, 255, 255, 255,
  18 255,  26,  27,  28,  29,  30,  31,  32,  33,  34,  35,  36,
  19  37,  38,  39,  40,  41,  42,  43,  44,  45,  46,  47,  48,
  20  49,  50,  51, 255, 255, 255, 255, 255, 255, 255, 255, 255,
  21 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
  22 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
  23 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
  24 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
  25 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
  26 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
  27 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
  28 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
  29 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
  30 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255,
  31 255, 255, 255, 255 };
  32
  33 int base64_encode(const unsigned char *in,  unsigned long len,
  34                         unsigned char *out, unsigned long *outlen)
  35 {
  36    unsigned long i, len2, leven;
  37    unsigned char *p;
  38
  39    _ARGCHK(in != NULL);
  40    _ARGCHK(out != NULL);
  41    _ARGCHK(outlen != NULL);
  42
  43    /* valid output size ? */
  44    len2 = 4 * ((len + 2) / 3);
  45    if (*outlen < len2 + 1) {
  46       return CRYPT_BUFFER_OVERFLOW;
  47    }
  48    p = out;
  49    leven = 3*(len / 3);
  50    for (i = 0; i < leven; i += 3) {
  51        *p++ = codes[in[0] >> 2];
  52        *p++ = codes[((in[0] & 3) << 4) + (in[1] >> 4)];
  53        *p++ = codes[((in[1] & 0xf) << 2) + (in[2] >> 6)];
  54        *p++ = codes[in[2] & 0x3f];
  55        in += 3;
  56    }
  57    /* Pad it if necessary...  */
  58    if (i < len) {
  59        unsigned a = in[0];
  60        unsigned b = (i+1 < len) ? in[1] : 0;
  61        unsigned c = 0;
  62
  63        *p++ = codes[a >> 2];
  64        *p++ = codes[((a & 3) << 4) + (b >> 4)];
  65        *p++ = (i+1 < len) ? codes[((b & 0xf) << 2) + (c >> 6)] : '=';
  66        *p++ = '=';
  67    }
  68
  69    /* append a NULL byte */
  70    *p = '\0';
  71
  72    /* return ok */
  73    *outlen = p - out;
  74    return CRYPT_OK;
  75 }
  76
  77 int base64_decode(const unsigned char *in,  unsigned long len,
  78                         unsigned char *out, unsigned long *outlen)
  79 {
  80    unsigned long t, x, y, z;
  81    unsigned char c;
  82    int  g = 3;
  83
  84    _ARGCHK(in != NULL);
  85    _ARGCHK(out != NULL);
  86    _ARGCHK(outlen != NULL);
  87
  88    for (x = y = z = t = 0; x < len; x++) {
  89        c = map[in[x]];
  90        if (c == 255) continue;
  91        if (c == 254) { c = 0; g--; }
  92        t = (t<<6)|c;
  93        if (++y == 4) {
  94            if (z + g > *outlen) { return CRYPT_BUFFER_OVERFLOW; }
  95           out[z++] = (unsigned char)((t>>16)&255);
  96           if (g > 1) out[z++] = (unsigned char)((t>>8)&255);
  97           if (g > 2) out[z++] = (unsigned char)(t&255);
  98           y = t = 0;
  99        }
 100    }
 101    if (y != 0) {
 102        return CRYPT_INVALID_PACKET;
 103    }
 104    *outlen = z;
 105    return CRYPT_OK;
 106 }
 107
 108 #endif
 109