new

src/cmd/upas/vf/unvf.c

@@ -0,0 +1,156 @@
+/*
+ * For decoding the files that get passed to validateattachment.
+ * NOT a general mime decoder.
+ */
+#include <u.h>
+#include <libc.h>
+#include <bio.h>
+
+enum { None, Base64, Quoted };
+static int decquoted(char *out, char *in, char *e);
+
+void
+main(void)
+{
+	Biobuf b, b1;
+	char *p, *encoding;
+	int e, len;
+	
+	Binit(&b, 0, OREAD);
+	Binit(&b1, 1, OWRITE);
+	
+	/* header */
+	encoding = nil;
+	while((p = Brdstr(&b, '\n', 1)) != nil){
+		if(p[0] == 0)
+			break;
+		if(strncmp(p, "Content-Transfer-Encoding: ", 27) == 0)
+			encoding = strdup(p+27);
+		free(p);
+	}
+
+	e = None;
+	if(encoding == nil)
+		e = None;
+	else if(strcmp(encoding, "base64") == 0)
+		e = Base64;
+	else if(strcmp(encoding, "quoted-printable") == 0)
+		e = Quoted;
+
+	while((p = Brdstr(&b, '\n', 0)) != nil){
+		if(strncmp(p, "--", 2) == 0 && e != None)
+			break;
+		len = strlen(p);
+		switch(e){
+		case None:
+			break;
+		case Base64:
+			len = dec64((uchar*)p, len, p, len);
+			break;
+		case Quoted:
+			len = decquoted(p, p, p+len);
+			break;
+		}
+		Bwrite(&b1, p, len);
+		free(p);
+	}
+	exits(0);
+}
+
+/*
+ *  decode quoted 
+ */
+enum
+{
+	Self=	1,
+	Hex=	2
+};
+uchar	tableqp[256];
+
+static void
+initquoted(void)
+{
+	int c;
+
+	memset(tableqp, 0, 256);
+	for(c = ' '; c <= '<'; c++)
+		tableqp[c] = Self;
+	for(c = '>'; c <= '~'; c++)
+		tableqp[c] = Self;
+	tableqp['\t'] = Self;
+	tableqp['='] = Hex;
+}
+
+static int
+hex2int(int x)
+{
+	if(x >= '0' && x <= '9')
+		return x - '0';
+	if(x >= 'A' && x <= 'F')
+		return (x - 'A') + 10;
+	if(x >= 'a' && x <= 'f')
+		return (x - 'a') + 10;
+	return 0;
+}
+
+static char*
+decquotedline(char *out, char *in, char *e)
+{
+	int c, soft;
+
+	/* dump trailing white space */
+	while(e >= in && (*e == ' ' || *e == '\t' || *e == '\r' || *e == '\n'))
+		e--;
+
+	/* trailing '=' means no newline */
+	if(*e == '='){
+		soft = 1;
+		e--;
+	} else
+		soft = 0;
+
+	while(in <= e){
+		c = (*in++) & 0xff;
+		switch(tableqp[c]){
+		case Self:
+			*out++ = c;
+			break;
+		case Hex:
+			c = hex2int(*in++)<<4;
+			c |= hex2int(*in++);
+			*out++ = c;
+			break;
+		}
+	}
+	if(!soft)
+		*out++ = '\n';
+	*out = 0;
+
+	return out;
+}
+
+static int
+decquoted(char *out, char *in, char *e)
+{
+	char *p, *nl;
+
+	if(tableqp[' '] == 0)
+		initquoted();
+
+	p = out;
+	while((nl = strchr(in, '\n')) != nil && nl < e){
+		p = decquotedline(p, in, nl);
+		in = nl + 1;
+	}
+	if(in < e)
+		p = decquotedline(p, in, e-1);
+
+	/* make sure we end with a new line */
+	if(*(p-1) != '\n'){
+		*p++ = '\n';
+		*p = 0;
+	}
+
+	return p - out;
+}
+