1 files changed, 137 insertions, 0 deletions
diff --git a/rfc2045/base64.c b/rfc2045/base64.c
new file mode 100644
index 0000000..bf676fd
--- /dev/null
+++ b/rfc2045/base64.c
@@ -0,0 +1,137 @@
+/*
+** Copyright 2002 Double Precision, Inc.  See COPYING for
+** distribution information.
+*/
+
+#include "rfc2045_config.h"
+#include "base64.h"
+
+#include <string.h>
+#include <stdio.h>
+
+void base64_decode_init(struct base64decode *b,
+			int (*f)(const char *, int, void *),
+			void *a)
+{
+	b->workbuflen=0;
+	b->decode_func=f;
+	b->decode_func_arg=a;
+}
+
+static int doflush(struct base64decode *);
+
+static const char base64tab[]=
+"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
+
+int base64_decode(struct base64decode *b, const char *p, int l)
+{
+	while (l)
+	{
+		char c;
+
+		if (b->workbuflen >= sizeof(b->workbuf))
+		{
+			int rc=doflush(b);
+
+			if (rc)
+				return (rc);
+		}
+
+
+		if (*p == '=')
+		{
+			c=100;
+		}
+		else
+		{
+			char *s=strchr(base64tab, *p);
+
+			if (s == NULL)
+			{
+				++p;
+				--l;
+				continue;
+			}
+
+			c= s-base64tab;
+		}
+		b->workbuf[b->workbuflen++]=c;
+		++p;
+		--l;
+	}
+	return (0);
+}
+
+int base64_decode_end(struct base64decode *b)
+{
+	return (doflush(b));
+}
+
+static int doflush(struct base64decode *p)
+{
+	int i=p->workbuflen / 4;
+	int j;
+	int k=0;
+
+	i= i * 4;
+
+	for (j=0; j<i; j += 4)
+	{
+		char	a,b,c;
+
+		int	w=p->workbuf[j];
+		int	x=p->workbuf[j+1];
+		int	y=p->workbuf[j+2];
+		int	z=p->workbuf[j+3];
+
+		a= (w << 2) | (x >> 4);
+		b= (x << 4) | (y >> 2);
+		c= (y << 6) | z;
+		p->workbuf[k++]=a;
+		if ( y != 100)
+			p->workbuf[k++]=b;
+		if ( z != 100)
+			p->workbuf[k++]=c;
+	}
+
+	j= (*p->decode_func)(p->workbuf, k, p->decode_func_arg);
+
+	k=0;
+	while (i < p->workbuflen)
+	{
+		p->workbuf[k]=p->workbuf[i];
+		++k;
+		++i;
+	}
+	p->workbuflen=k;
+	return (j);
+}
+
+/* ---- */
+
+static int save_str(const char *p, int l, void *vp)
+{
+	memcpy(*(char **)vp, p, l);
+
+	*(char **)vp += l;
+	return (0);
+}
+
+char *base64_decode_str(const char *s)
+{
+	struct base64decode b;
+
+	char *p=strdup(s);
+	char *pp;
+
+	if (!p)
+		return (NULL);
+
+	pp= p;
+
+	base64_decode_init(&b, save_str, &pp);
+	base64_decode(&b, s, strlen(s));
+	base64_decode_end(&b);
+	*pp=0;
+	return p;
+}