| /* LibTomCrypt, modular cryptographic library -- Tom St Denis |
| * |
| * LibTomCrypt is a library that provides various cryptographic |
| * algorithms in a highly modular and flexible manner. |
| * |
| * The library is free for all purposes without any express |
| * guarantee it works. |
| * |
| * Tom St Denis, tomstdenis@iahu.ca, http://libtomcrypt.org |
| */ |
| /* compliant base64 code donated by Wayne Scott (wscott@bitmover.com) */ |
| #include "mycrypt.h" |
| |
| #ifdef BASE64 |
| |
| static const char *codes = |
| "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"; |
| |
| static const unsigned char map[256] = { |
| 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, |
| 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, |
| 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, |
| 255, 255, 255, 255, 255, 255, 255, 62, 255, 255, 255, 63, |
| 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 255, 255, |
| 255, 254, 255, 255, 255, 0, 1, 2, 3, 4, 5, 6, |
| 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, |
| 19, 20, 21, 22, 23, 24, 25, 255, 255, 255, 255, 255, |
| 255, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, |
| 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, |
| 49, 50, 51, 255, 255, 255, 255, 255, 255, 255, 255, 255, |
| 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, |
| 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, |
| 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, |
| 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, |
| 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, |
| 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, |
| 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, |
| 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, |
| 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, |
| 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255, |
| 255, 255, 255, 255 }; |
| |
| int base64_encode(const unsigned char *in, unsigned long len, |
| unsigned char *out, unsigned long *outlen) |
| { |
| unsigned long i, len2, leven; |
| unsigned char *p; |
| |
| _ARGCHK(in != NULL); |
| _ARGCHK(out != NULL); |
| _ARGCHK(outlen != NULL); |
| |
| /* valid output size ? */ |
| len2 = 4 * ((len + 2) / 3); |
| if (*outlen < len2 + 1) { |
| return CRYPT_BUFFER_OVERFLOW; |
| } |
| p = out; |
| leven = 3*(len / 3); |
| for (i = 0; i < leven; i += 3) { |
| *p++ = codes[(in[0] >> 2) & 0x3F]; |
| *p++ = codes[(((in[0] & 3) << 4) + (in[1] >> 4)) & 0x3F]; |
| *p++ = codes[(((in[1] & 0xf) << 2) + (in[2] >> 6)) & 0x3F]; |
| *p++ = codes[in[2] & 0x3F]; |
| in += 3; |
| } |
| /* Pad it if necessary... */ |
| if (i < len) { |
| unsigned a = in[0]; |
| unsigned b = (i+1 < len) ? in[1] : 0; |
| |
| *p++ = codes[(a >> 2) & 0x3F]; |
| *p++ = codes[(((a & 3) << 4) + (b >> 4)) & 0x3F]; |
| *p++ = (i+1 < len) ? codes[(((b & 0xf) << 2)) & 0x3F] : '='; |
| *p++ = '='; |
| } |
| |
| /* append a NULL byte */ |
| *p = '\0'; |
| |
| /* return ok */ |
| *outlen = p - out; |
| return CRYPT_OK; |
| } |
| |
| int base64_decode(const unsigned char *in, unsigned long len, |
| unsigned char *out, unsigned long *outlen) |
| { |
| unsigned long t, x, y, z; |
| unsigned char c; |
| int g; |
| |
| _ARGCHK(in != NULL); |
| _ARGCHK(out != NULL); |
| _ARGCHK(outlen != NULL); |
| |
| g = 3; |
| for (x = y = z = t = 0; x < len; x++) { |
| c = map[in[x]&0xFF]; |
| if (c == 255) continue; |
| if (c == 254) { c = 0; g--; } |
| t = (t<<6)|c; |
| if (++y == 4) { |
| if (z + g > *outlen) { |
| return CRYPT_BUFFER_OVERFLOW; |
| } |
| out[z++] = (unsigned char)((t>>16)&255); |
| if (g > 1) out[z++] = (unsigned char)((t>>8)&255); |
| if (g > 2) out[z++] = (unsigned char)(t&255); |
| y = t = 0; |
| } |
| } |
| if (y != 0) { |
| return CRYPT_INVALID_PACKET; |
| } |
| *outlen = z; |
| return CRYPT_OK; |
| } |
| |
| #endif |
| |