diff options
Diffstat (limited to 'src/ltc/misc/base64/base64_encode.c')
-rw-r--r-- | src/ltc/misc/base64/base64_encode.c | 126 |
1 files changed, 126 insertions, 0 deletions
diff --git a/src/ltc/misc/base64/base64_encode.c b/src/ltc/misc/base64/base64_encode.c new file mode 100644 index 00000000..ea3eaddd --- /dev/null +++ b/src/ltc/misc/base64/base64_encode.c @@ -0,0 +1,126 @@ +/* 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@gmail.com, http://libtom.org + */ +#include "tomcrypt.h" + +/** + @file base64_encode.c + Compliant base64 encoder donated by Wayne Scott (wscott@bitmover.com) + base64 URL Safe variant (RFC 4648 section 5) by Karel Miko +*/ + + +#if defined(LTC_BASE64) || defined (LTC_BASE64_URL) + +#if defined(LTC_BASE64) +static const char * const codes_base64 = +"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"; +#endif /* LTC_BASE64 */ + +#if defined(LTC_BASE64_URL) +static const char * const codes_base64url = +"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789-_"; +#endif /* LTC_BASE64_URL */ + +static int _base64_encode_internal(const unsigned char *in, unsigned long inlen, + unsigned char *out, unsigned long *outlen, + const char *codes, int pad) +{ + unsigned long i, len2, leven; + unsigned char *p; + + LTC_ARGCHK(in != NULL); + LTC_ARGCHK(out != NULL); + LTC_ARGCHK(outlen != NULL); + + /* valid output size ? */ + len2 = 4 * ((inlen + 2) / 3); + if (*outlen < len2 + 1) { + *outlen = len2 + 1; + return CRYPT_BUFFER_OVERFLOW; + } + p = out; + leven = 3*(inlen / 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 < inlen) { + unsigned a = in[0]; + unsigned b = (i+1 < inlen) ? in[1] : 0; + + *p++ = codes[(a >> 2) & 0x3F]; + *p++ = codes[(((a & 3) << 4) + (b >> 4)) & 0x3F]; + if (pad) { + *p++ = (i+1 < inlen) ? codes[(((b & 0xf) << 2)) & 0x3F] : '='; + *p++ = '='; + } + else { + if (i+1 < inlen) *p++ = codes[(((b & 0xf) << 2)) & 0x3F]; + } + } + + /* append a NULL byte */ + *p = '\0'; + + /* return ok */ + *outlen = (unsigned long)(p - out); + return CRYPT_OK; +} + +#if defined(LTC_BASE64) +/** + base64 Encode a buffer (NUL terminated) + @param in The input buffer to encode + @param inlen The length of the input buffer + @param out [out] The destination of the base64 encoded data + @param outlen [in/out] The max size and resulting size + @return CRYPT_OK if successful +*/ +int base64_encode(const unsigned char *in, unsigned long inlen, + unsigned char *out, unsigned long *outlen) +{ + return _base64_encode_internal(in, inlen, out, outlen, codes_base64, 1); +} +#endif /* LTC_BASE64 */ + + +#if defined(LTC_BASE64_URL) +/** + base64 (URL Safe, RFC 4648 section 5) Encode a buffer (NUL terminated) + @param in The input buffer to encode + @param inlen The length of the input buffer + @param out [out] The destination of the base64 encoded data + @param outlen [in/out] The max size and resulting size + @return CRYPT_OK if successful +*/ +int base64url_encode(const unsigned char *in, unsigned long inlen, + unsigned char *out, unsigned long *outlen) +{ + return _base64_encode_internal(in, inlen, out, outlen, codes_base64url, 0); +} + +int base64url_strict_encode(const unsigned char *in, unsigned long inlen, + unsigned char *out, unsigned long *outlen) +{ + return _base64_encode_internal(in, inlen, out, outlen, codes_base64url, 1); +} +#endif /* LTC_BASE64_URL */ + +#endif + + +/* $Source$ */ +/* $Revision$ */ +/* $Date$ */ |