Added dkim detection

Signed-off-by: tyrolyean <tyrolyean@tyrolyean.net>

include/detect.h

@@ -23,6 +23,7 @@
 #include "attach.h"
 
 bool detect_pgp(struct email_t* mail);
+bool detect_dkim(struct email_t* mail);
 char* detect_start_of_body(char* message);
 char* detect_end_of_body(char* message);
 #endif /* DETECT_H */

include/tools.h

@@ -23,4 +23,5 @@
 const char* insert_string(char * destination, const char* source, 
 	size_t dest_orig_len, size_t offset);
 
+
 #endif /* TOOLS_H */

src/attach.c

@@ -83,17 +83,16 @@ char* attach_files(char* message, size_t len){
 
 	struct email_t email = mail_from_text(message,len);
 	
-	printf("Received message header: [%.*s]\n", email.header_len, 
-		email.message);
-	printf("Received message body: [%.*s]\n", 
-		email.message_length-email.body_offset,
-		email.message + email.body_offset);
-
 	/* Check if mails are signed/encrypted, and abort if nescessary */
 	if(abort_on_pgp && detect_pgp(&email)){
 		printf("PGP detected, aborting...");
 		return email.message;
 	}
+	/* Check if mails are signed/encrypted, and abort if nescessary */
+	if(abort_on_dkim && detect_dkim(&email)){
+		printf("DKIM signature detected, aborting...");
+		return email.message;
+	}
 
 	return email.message;
 }

src/detect.c

@@ -29,6 +29,11 @@ char* pgp_signatures[] =
 	"-----BEGIN PGP MESSAGE-----"
 };
 
+char* dkim_signatures[] = 
+{
+	"DKIM-Signature:"
+};
+
 bool detect_pgp(struct email_t* mail){
 		
 	size_t points = 0;
@@ -45,6 +50,23 @@ bool detect_pgp(struct email_t* mail){
 	return points >= 2;
 }
 
+bool detect_dkim(struct email_t* mail){
+		
+	size_t points = 0;
+	
+	for(size_t i = 0; i < (sizeof(dkim_signatures)/sizeof(char*));i++){
+		if(strcasestr(mail->message, dkim_signatures[i]) != NULL
+				&& strcasestr(mail->message, dkim_signatures[i])
+				<= (mail->message+mail->header_len)){
+			points++;
+		}
+		
+	}
+	
+
+	return points >= 1;
+}
+
 /* If body hasn't started yet, it returns NULL, if it has started, it returns
  * the pointer to the beginning of the newline.
  */

src/main.c

@@ -63,8 +63,10 @@ int main(int argc, char* argv[]){
 
 	printf("Incoming port: %u outgoing port: %u on loopback interface\n",
 		 listen_port, forward_port);
+
 	printf("Ignoring PGP signed/encrypted messages: %s\n",
 		abort_on_pgp ? "true":false);
+
 	printf("Ignoring DKIM signed messages: %s\n",
 		abort_on_dkim ? "true" : "false");