add rfc2045 and multipart decoding

1 files changed, 131 insertions, 0 deletions

diff --git a/rfc2045.c b/rfc2045.c
new file mode 100644
index 0000000..cb6d317
--- /dev/null
+++ b/rfc2045.c
@@ -0,0 +1,131 @@
+#define _GNU_SOURCE
+#include <string.h>
+
+#include "blaze822.h"
+#include "blaze822_priv.h"
+
+int
+blaze822_check_mime(struct message *msg)
+{
+        char *v = blaze822_hdr(msg, "mime-version");
+	return (v &&
+	    v[0] && v[0] == '1' &&
+	    v[1] && v[1] == '.' &&
+	    v[2] && v[2] == '0' &&
+	    (!v[3] || iswsp(v[3])));
+}
+
+int
+blaze822_mime_body(struct message *msg, char **cto, char **bodyo, size_t *bodyleno)
+{
+	if (!msg->body || !msg->bodyend)
+		return -1;
+
+	char *ct = blaze822_hdr(msg, "content-type");
+	char *cte = blaze822_hdr(msg, "content-transfer-encoding");
+
+	if (!ct)
+		ct = "text/plain; charset=US-ASCII";
+
+	char *s = ct;
+	while (*s && *s != ';')
+		s++;
+
+	*cto = ct;
+
+	if (cte) {
+		if (strncasecmp(cte, "quoted-printable", 16) == 0)
+			blaze822_decode_qp(msg->body, msg->bodyend, bodyo, bodyleno);
+		else if (strncasecmp(cte, "base64", 6) == 0)
+			blaze822_decode_b64(msg->body, msg->bodyend, bodyo, bodyleno);
+		else
+			cte = 0;
+	}
+	if (!cte) {
+		*bodyo = msg->body;
+		*bodyleno = msg->bodyend - msg->body;
+	}
+
+	return 1;
+}
+
+int
+blaze822_multipart(struct message *msg, struct message **imsg)
+{
+	char *s = blaze822_hdr(msg, "content-type");
+	if (!s)
+		return 0;
+	while (*s && *s != ';')
+		s++;
+	if (!*s)
+		return 0;
+
+	// XXX scan boundary only once
+	char *boundary = s+1;
+	while (*boundary) {
+		while (iswsp(*boundary))
+			boundary++;
+		if (strncasecmp(boundary, "boundary=", 9) == 0) {
+			boundary += 9;
+			break;
+		}
+		boundary = strchr(boundary+1, ';');
+		if (!boundary)
+			break;
+		boundary++;
+	}
+	if (!boundary || !*boundary)
+		return 0;
+	char *e;
+	if (*boundary == '"') {
+		boundary++;
+		e = strchr(boundary, '"');
+		if (!e)
+			return 0;
+	} else {
+		e = boundary;
+		// XXX    bchars := bcharsnospace / " "
+		// bcharsnospace := DIGIT / ALPHA / "'" / "(" / ")" /
+		//              "+" / "_" / "," / "-" / "." /
+		//              "/" / ":" / "=" / "?"
+		while(!iswsp(*e) && *e != ';')
+			e++;
+		e++;
+	}
+
+	char mboundary[256];
+	mboundary[0] = '-';
+	mboundary[1] = '-';
+	memcpy(mboundary+2, boundary, e-boundary);  // XXX overflow
+	mboundary[e-boundary+2] = 0;
+
+	int boundarylen = e-boundary+2;
+
+//	printf("boundary: %s %s %s\n", ct, cte, boundary);
+
+	char *prevpart;
+	if (*imsg)
+		prevpart = (*imsg)->bodyend;
+	else
+		prevpart = msg->body;
+
+	char *part = memmem(prevpart, msg->bodyend - prevpart, mboundary, boundarylen);
+	if (!part)
+		return 0;
+	/// XXX access to stuff before first boundary?
+	part += boundarylen;
+	if (*part == '\n')    // XXX crlf
+		part++;
+	else if (*part == '-' && part < msg->bodyend && *(part+1) == '-')
+		return 0;
+	else
+		return 0;   // XXX error condition?
+
+	char *nextpart = memmem(part, msg->bodyend - part, mboundary, boundarylen);
+	if (!nextpart)
+		return 0;   // XXX error condition
+
+	*imsg = blaze822_mem(part, nextpart-part);
+
+	return 1;
+}