sick

commit c781b566414ba4ad22f2018c57f6876c23e5e0d9
parent efa917d9e3ed2304b728d4263944ecc86120656d
Author: z3bra <willyatmailoodotorg>
Date:   Sat May  7 11:42:29 +12000

base64_encode() working

Diffstat:
base64.c
 | 
67
+++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
base64.h
 | 
15
+++++++++++++++
2 files changed, 82 insertions(+), 0 deletions(-)
diff --git a/base64.c b/base64.c
@@ -0,0 +1,67 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <stdint.h>
+#include <unistd.h>
+
+#include "base64.h"
+
+size_t
+base64_encode(char **buf, const unsigned char *msg, size_t len)
+{
+	int i, j;
+	uint64_t b64;
+	size_t size;
+
+	/* calculate size needed for the base64 buffer */
+	size = 1 + (len / 3) * 4 + (len % 3 ? 4 : 0);
+
+	*buf = malloc(size);
+	memset(*buf, 0, size);
+
+	for (i = j = 0; i < len; i+=3) {
+		/* concatenate 3 bytes into one 24 bits quantum, or 0 */
+		b64 = 0 | (msg[i]<<16);
+		b64 |= ((i+1 < len ? msg[i+1] : 0) << 8);
+		b64 |= i+2 < len ? msg[i+2] : 0;
+
+		/* extract 4 base64 values from it */
+		(*buf)[j++] = base64_table[63 & (b64>>18)];
+		(*buf)[j++] = base64_table[63 & (b64>>12)];
+		(*buf)[j++] = i+1 < len ? base64_table[63 & (b64>>6)] : '=';
+		(*buf)[j++] = i+2 < len ? base64_table[63 & b64] : '=';
+	}
+
+	return size;
+}
+
+size_t
+base64_decode(char **buf, const unsigned char *msg, size_t len)
+{
+	size_t size;
+
+	size = 1 + (len / 4 ) * 3;
+	size -= msg[len - 1] == '=' ? 1 : 0;
+	size -= msg[len - 2] == '=' ? 1 : 0;
+
+	printf("base64: %lu bytes\n", len);
+	printf("clear : %lu bytes\n", size);
+
+	return size;
+}
+
+int
+main(int argc, char *argv[])
+{
+	int i;
+	size_t len, n;
+	char *buf = NULL, in[59];
+
+	while ((n = read(0, in, 57)) > 0) {
+		in[58] = 0;
+		len = base64_encode(&buf, in, n);
+		puts(buf);
+		free(buf);
+	}
+	return 0;
+}
diff --git a/base64.h b/base64.h
@@ -0,0 +1,15 @@
+#ifndef BASE64_H__
+#define BASE64_H__
+
+size_t base64_encode(char **buf, const unsigned char *msg, size_t len);
+size_t base64_decode(char **buf, const unsigned char *msg, size_t len);
+
+const char base64_table[] = {
+	'A','B','C','D','E','F','G','H','I','J','K','L','M',
+	'N','O','P','Q','R','S','T','U','V','W','X','Y','Z',
+	'a','b','c','d','e','f','g','h','i','j','k','l','m',
+	'n','o','p','q','r','s','t','u','v','w','x','y','z',
+	'0','1','2','3','4','5','6','7','8','9','+','/'
+};
+
+#endif