Mercurial > dropbear
diff base64_encode.c @ 15:6362d3854bb4 libtomcrypt-orig
0.96 release of LibTomCrypt
author | Matt Johnston <matt@ucc.asn.au> |
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date | Tue, 15 Jun 2004 14:07:21 +0000 |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/base64_encode.c Tue Jun 15 14:07:21 2004 +0000 @@ -0,0 +1,63 @@ +/* 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, [email protected], http://libtomcrypt.org + */ +/* compliant base64 code donated by Wayne Scott ([email protected]) */ +#include "mycrypt.h" + +#ifdef BASE64 + +static const char *codes = +"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"; + +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; +} + +#endif +