diff src/misc/base64/base64_encode.c @ 191:1c15b283127b libtomcrypt-orig

Import of libtomcrypt 1.02 with manual path rename rearrangement etc
author Matt Johnston <matt@ucc.asn.au>
date Fri, 06 May 2005 13:23:02 +0000
parents
children 39d5d58461d6
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--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/misc/base64/base64_encode.c	Fri May 06 13:23:02 2005 +0000
@@ -0,0 +1,76 @@
+/* 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
+ */
+#include "tomcrypt.h"
+
+/**
+  @file base64_encode.c
+  Compliant base64 encoder donated by Wayne Scott ([email protected])
+*/
+
+
+#ifdef BASE64
+
+static const char *codes = 
+"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
+
+/**
+   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)
+{
+   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) {
+      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];
+       *p++ = (i+1 < inlen) ? codes[(((b & 0xf) << 2)) & 0x3F] : '=';
+       *p++ = '=';
+   }
+
+   /* append a NULL byte */
+   *p = '\0';
+
+   /* return ok */
+   *outlen = p - out;
+   return CRYPT_OK;
+}
+
+#endif
+