Improved filename handling and securiteee

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

include/config.h

@@ -24,7 +24,7 @@ extern uint16_t listen_port, forward_port;
 
 /* Used as booleans, but integers for getops sake... */
 
-extern int abort_on_pgp, abort_on_dkim;
+extern int abort_on_pgp, abort_on_dkim, only_base64;
 
 extern char* instance_id;
 

include/file.h

@@ -25,9 +25,12 @@
 char* generate_safe_dirname();
 
 int base64_decode_file(const char* directory, const struct email_t* mail);
+
 int decode_file(const char* directory, const char * message, size_t len,
-	struct type_file_info_t finf);
+	char* name);
 
 bool file_exists(const char* filename);
 
+char* sanitizie_filename(char* filename);
+
 #endif /* FILE_H */

src/attach.c

@@ -212,6 +212,9 @@ void unravel_multipart_mail(struct email_t* mail){
 
 void free_submails(struct email_t* mail){
 	
+	free(mail->file_info.name);
+	free(mail->file_info.mime_type);
+
 	if(!mail->is_multipart){
 		return;
 	}
@@ -336,6 +339,10 @@ int replace_base64_files(struct email_t* mail, const char* dirname){
 		return 0;
 
 	}
+	if(mail->file_info.name == NULL){
+		return 0;
+	}
+	
 	if(mail->base64_encoded){
 		if(base64_decode_file(dirname, mail) < 0){
 			fprintf(stderr, "Failed to decode base64 file\n!");
@@ -344,7 +351,7 @@ int replace_base64_files(struct email_t* mail, const char* dirname){
 	}else{
 		if(decode_file(dirname, (mail->message+mail->body_offset),
 			 (mail->message_length - mail->body_offset), 
-			 mail->file_info) < 0){
+			 mail->file_info.name) < 0){
 			
 			fprintf(stderr, "Failed to decode base64 file\n!");
 			return -1;

src/config.c

@@ -20,10 +20,11 @@
 #include <stddef.h>
 
 uint16_t listen_port = 4269, forward_port = 4270;
-int abort_on_pgp = true, abort_on_dkim = true;
+int abort_on_pgp = true, abort_on_dkim = true, only_base64 = true;
 char* instance_id = NULL;
 
 int verbose = false;
 char* directory = NULL;
 char* url_base = NULL;
 
+

src/file.c

@@ -27,6 +27,7 @@
 #include <sys/stat.h>
 #include <fcntl.h>
 #include <sys/random.h>
+#include <ctype.h>
 
 /* Generate a safe directory name to store ONE emails files into. This is
  * done to prevent someone from guessing the directory names. THe first part
@@ -44,14 +45,14 @@ char* generate_safe_dirname(){
 #define TIME_LEN 30
         char datestr[TIME_LEN];
 	memset(datestr, 0, TIME_LEN);
-        strftime(datestr, TIME_LEN, "%FT%T%z", info);
+        strftime(datestr, TIME_LEN, "%FT%H%M", info);
 
 	/* Get data from urandom to be  secure. I mean from what I
 	 * know it should be, but I'm not a crypto expert. If you have doubts
 	 * and know how I should do that, PLEASE TELL ME! The man pages told me
 	 * to do so!
 	 */
-	int randie[3];
+	int randie[2];
 	
 	if(getrandom(randie, sizeof(randie), 0) <= 0){
 		perror("Failed to get random seed! Aborting");
@@ -62,8 +63,8 @@ char* generate_safe_dirname(){
 	char * dir_id = malloc(dir_len+1);
 	memset(dir_id, 0, dir_len+1 );
 
-	snprintf(dir_id,dir_len, "%s/%s%i%i%i/",directory, datestr,
-		randie[0], randie[1], randie[2]);
+	snprintf(dir_id,dir_len, "%s/%s%i%i/",directory, datestr,
+		randie[0], randie[1]);
 #undef TIME_LEN
 	return dir_id;
 }
@@ -90,7 +91,8 @@ int base64_decode_file(const char* directory, const struct email_t* mail){
 		return -1;
 	}
 	
-	int n = decode_file(directory,(char*) decoded, dec_len, mail->file_info);
+	int n = decode_file(directory,(char*) decoded, dec_len, 
+		mail->file_info.name);
 	
 	free(decoded);
 
@@ -99,15 +101,16 @@ int base64_decode_file(const char* directory, const struct email_t* mail){
 }
 
 int decode_file(const char* directory, const char * message, size_t len, 
-	struct type_file_info_t finf){
+	char* name){
 
-	if(directory == NULL || message == NULL || finf.name == NULL){
+	if(directory == NULL || message == NULL || name == NULL){
 
 		/* I don't know how I should call that file! */
 		return 0;
 	}
+	char* sane_name = sanitizie_filename(name);
 	
-	size_t fn_len = strlen(finf.name) + strlen(directory) + 1;
+	size_t fn_len = strlen(sane_name) + strlen(directory) + 1;
 	
 	char* filename = malloc(fn_len);
 	if(filename == NULL){
@@ -116,20 +119,24 @@ int decode_file(const char* directory, const char * message, size_t len,
 
 	memset(filename, 0, fn_len);
 	strcat(filename, directory);
-	strcat(filename, finf.name);
-
+	strcat(filename, sane_name);
+	
+	
 	bool exists = false;
 	for(size_t i = 0; i < 10; i++){
 		exists = file_exists(filename);
 		if(exists){
 			free(filename);
-			fn_len = strlen(finf.name) + 
+			fn_len = strlen(sane_name) + 
 				strlen(directory) + 20;
 			filename = malloc(fn_len);
 			snprintf(filename, fn_len, "%s%i-%s",directory,
-				rand(), finf.name);
+				rand(), sane_name);
 		}
 	}
+	
+	free(sane_name);
+	
 	if(exists){
 		/* What?*/
 		fprintf(stderr,"Failed to create unique file name!\n");
@@ -164,3 +171,23 @@ bool file_exists(const char* filename){
 		return false;
 	}
 }
+
+/* Generates a filename which should fit into a URL without URL-encode and which
+ * doesn't allow for  */
+char* sanitizie_filename(char* filename){
+	
+	if(filename == NULL){
+		return NULL;
+	}
+	size_t filename_len = strlen(filename);
+	size_t new_len = 0;
+	char* new_name = malloc(filename_len + 1);
+	memset(new_name, 0, filename_len+1);
+	for(size_t i = 0; i < filename_len; i++){
+		if(isalnum(filename[i]) || filename[i] == '-' || 
+			filename[i] == '.'){
+			new_name[new_len++] = filename[i];
+		}
+	}
+	return new_name;
+}

src/main.c

@@ -30,6 +30,8 @@ int main(int argc, char* argv[]){
 			{"noabort-dkim",no_argument, &abort_on_dkim,0},
 			{"verbose",	no_argument, &verbose,      1},
 			{"quiet",	no_argument, &verbose,      0},
+			{"only-base64",	no_argument, &only_base64,  1},
+			{"other-base64",no_argument, &only_base64,  0},
 			{"in-port",	required_argument, 0, 'i'},
 			{"out-port",	required_argument, 0, 'o'},
 			{"instance-id",	required_argument, 0, 'n'},
@@ -106,15 +108,19 @@ 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",
+		printf("Aborting on PGP signed/encrypted messages: %s\n",
 			abort_on_pgp ? "true":false);
 
-		printf("Ignoring DKIM signed messages: %s\n",
+		printf("Aborting on DKIM signed messages: %s\n",
 			abort_on_dkim ? "true" : "false");
 		
 		printf("Instance id for messages: %s\n",
 			instance_id);
 		
+		printf("Only saving bas64 encoded files: %s\n",
+			only_base64 ? "true":false);
+
+		
 		printf("Placing files into [%s] linked by [%s]\n", directory,
 		url_base);
 	}