added base64 codec

src/base64.c

@@ -0,0 +1,159 @@
+/*
+ * Copyright (c) 2006-2007 Bjorn Andersson <flex@kryo.se>, Erik Ekman <yarrick@kryo.se>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+
+#include "encoding.h"
+#include "base64.h"
+
+static const char cb64[] = 
+	"abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ-0123456789.";
+static unsigned char rev64[128];
+static int reverse_init = 0;
+
+static struct encoder base64_encoder =
+{
+	"BASE64",
+	base64_encode,
+	base64_decode,
+	base64_handles_dots,
+	base64_handles_dots
+};
+
+struct encoder
+*get_base64_encoder()
+{
+	return &base64_encoder;
+}
+
+int 
+base64_handles_dots()
+{
+	return 1;
+}
+
+int 
+base64_encode(char *buf, size_t *buflen, const void *data, size_t size)
+{
+	size_t newsize;
+	size_t maxsize;
+	unsigned char *s;
+	unsigned char *p;
+	unsigned char *q;
+	int i;
+
+	memset(buf, 0, *buflen);
+
+	/* how many chars can we encode within the buf */
+	maxsize = 3 * (*buflen / 4 - 1) - 1;
+	/* how big will the encoded data be */
+	newsize = 4 * (size / 3 + 1) + 1;
+	/* if the buffer is too small, eat some of the data */
+	if (*buflen < newsize) {
+		size = maxsize;
+	}
+
+	p = s = (unsigned char *) buf;
+	q = (unsigned char *)data;
+
+	for(i=0;i<size;i+=3) {
+		p[0] = cb64[((q[0] & 0xfc) >> 2)];
+		p[1] = cb64[(((q[0] & 0x03) << 4) | ((q[1] & 0xf0) >> 4))];
+		p[2] = (i+1 < size) ? cb64[((q[1] & 0x0f) << 2 ) | ((q[2] & 0xc0) >> 6)] : '\0';
+		p[3] = (i+2 < size) ? cb64[(q[2] & 0x3f)] : '\0';
+		
+		q += 3;
+		p += 4;
+	}	
+	*p = 0;
+
+	/* store number of bytes from data that was used */
+	*buflen = size;
+
+	return strlen(buf) - 1;
+}
+
+#define DECODE_ERROR 0xffffffff
+#define REV64(x) rev64[(int) (x)]
+
+static int
+decode_token(const unsigned char *t, unsigned char *data, size_t len) 
+{
+	if (len < 2)
+		return 0;
+
+	data[0] = ((REV64(t[0]) & 0x3f) << 2) | 
+			  ((REV64(t[1]) & 0x30) >> 4);
+
+	if (len < 3)
+		return 1;
+
+	data[1] = ((REV64(t[1]) & 0x0f) << 4) | 
+			  ((REV64(t[2]) & 0x3c) >> 2);
+
+	if (len < 4)
+		return 2;
+
+	data[2] = ((REV64(t[2]) & 0x03) << 6) |
+			  (REV64(t[3]) & 0x3f);
+
+	return 3;
+}
+
+int
+base64_decode(void *buf, size_t *buflen, const char *str, size_t slen)
+{
+	unsigned char *q;
+	size_t newsize;
+	size_t maxsize;
+	const char *p;
+	unsigned char c;
+	int len;
+	int i;
+
+	if (!reverse_init) {
+		for (i = 0; i < 64; i++) {
+			c = cb64[i];
+			rev64[(int) c] = i;
+		}
+		reverse_init = 1;
+	}
+	
+	/* chars needed to decode slen */
+	newsize = 3 * (slen / 4 + 1) + 1;
+	/* encoded chars that fit in buf */
+	maxsize = 4 * (*buflen / 3 + 1) + 1;
+	/* if the buffer is too small, eat some of the data */
+	if (*buflen < newsize) {
+		slen = maxsize;
+	}
+
+	q = buf;
+	for (p = str; *p && strchr(cb64, *p); p += 4) {
+		len = decode_token((unsigned char *) p, (unsigned char *) q, slen);	
+		q += len;
+		slen -= 4;
+		
+		if (len < 3)
+			break;
+	}
+	*q = '\0';
+	
+	return q - (unsigned char *) buf;
+}
+

src/base64.h

@@ -0,0 +1,25 @@
+/*
+ * Copyright (c) 2006-2007 Bjorn Andersson <flex@kryo.se>, Erik Ekman <yarrick@kryo.se>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#ifndef __BASE64_H__
+#define __BASE64_H__
+
+struct encoder *get_base64_encoder(void);
+int base64_handles_dots();
+int base64_encode(char *, size_t *, const void *, size_t);
+int base64_decode(void *, size_t *, const char *, size_t);
+
+#endif