From c7b5e1df086bcc37ff40163ee67571f076cf6683 Mon Sep 17 00:00:00 2001
From: markus schnalke <meillo@marmaro.de>
Date: Sat, 7 Jul 2012 12:31:38 +0200
Subject: [PATCH] send: Sign and encrypt messages automatically, based on
 Sign: and Enc: Hdrs. Currently, the value of the header
 fields is ignored. The sole presence of such a header
 caused signing or encryption.

---
 config/config.c     |    4 ++-
 h/mh.h              |    2 ++
 man/mh-profile.man5 |   24 ++++++++++++++++++
 sbr/readconfig.c    |    2 ++
 uip/mhparam.c       |    2 ++
 uip/send.c          |   68 +++++++++++++++++++++++++++++++++++++++++++++++++++
 6 files changed, 101 insertions(+), 1 deletion(-)

diff --git a/config/config.c b/config/config.c
index 935c92d..52ef436 100644
--- a/config/config.c
+++ b/config/config.c
@@ -94,8 +94,10 @@ char *nsequence = "Sequence-Negation";
 /* profile entries for storage locations */
 char *nmhstorage   = "nmh-storage";
 
-/* Default attachment header field name */
+/* Default header field names */
 char *attach_hdr = "Attach";
+char *sign_hdr = "Sign";
+char *enc_hdr = "Enc";
 
 /* the tool to query the mime type of a file */
 char *mimetypequery = "Mime-Type-Query";
diff --git a/h/mh.h b/h/mh.h
index bee5518..1331a14 100644
--- a/h/mh.h
+++ b/h/mh.h
@@ -273,6 +273,8 @@ extern char *mailstore;      /* name of mail storage directory  */
 ** on any system.
 */
 extern char *attach_hdr;
+extern char *sign_hdr;
+extern char *enc_hdr;
 extern char *components;
 extern char *context;
 extern char *curfolder;
diff --git a/man/mh-profile.man5 b/man/mh-profile.man5
index a3f5ae2..1499c06 100644
--- a/man/mh-profile.man5
+++ b/man/mh-profile.man5
@@ -182,6 +182,30 @@ If you like to type a lot, name it `X-MH-Attachment'.
 (profile, default: `Attach')
 .RE
 .PP
+.BR Sign-Header :
+Sign
+.RS 5
+The (pseudo) header in draft messages, that requests the message to be
+signed automatically by
+.BR send ,
+using
+.BR mhsign .
+If you like to type a lot, name it `X-MH-Sign-This-Message'.
+(profile, default: `Sign')
+.RE
+.PP
+.BR Enc-Header :
+Enc
+.RS 5
+The (pseudo) header in draft messages, that requests the message to be
+signed and encrypted by
+.BR send ,
+using
+.BR mhsign .
+If you like to type a lot, name it `X-MH-Encrypt-This-Message'.
+(profile, default: `Enc')
+.RE
+.PP
 .BR Mime-Type-Query :
 file \-b \-\-mime
 .RS 5
diff --git a/sbr/readconfig.c b/sbr/readconfig.c
index 1b00bf9..d93d04b 100644
--- a/sbr/readconfig.c
+++ b/sbr/readconfig.c
@@ -17,6 +17,8 @@ struct procstr {
 
 static struct procstr procs[] = {
 	{ "attachment-header",  &attach_hdr },
+	{ "sign-header",   &sign_hdr },
+	{ "enc-header",    &enc_hdr },
 	{ "context",       &context },
 	{ "mh-sequences",  &mh_seq },
 	{ "draft-folder",  &draftfolder },
diff --git a/uip/mhparam.c b/uip/mhparam.c
index 87b4d17..4e1fc21 100644
--- a/uip/mhparam.c
+++ b/uip/mhparam.c
@@ -34,6 +34,8 @@ struct proc {
 
 static struct proc procs [] = {
 	{ "attachment-header",  &attach_hdr },
+	{ "sign-header",   &sign_hdr },
+	{ "enc-header",    &enc_hdr },
 	{ "context",       &context },
 	{ "mh-sequences",  &mh_seq },
 	{ "editor",        &defaulteditor },
diff --git a/uip/send.c b/uip/send.c
index 0660e95..76280aa 100644
--- a/uip/send.c
+++ b/uip/send.c
@@ -46,6 +46,7 @@ static void armed_done(int) NORETURN;
 static void anno(struct stat *);
 static int sendaux(char **, int, char *, struct stat *);
 static int attach(char *);
+static int signandenc(char *);
 static void clean_up_temporary_files(void);
 static int get_line(void);
 static void make_mime_composition_file_entry(char *);
@@ -261,6 +262,26 @@ sendsbr(char **vec, int vecp, char *drft, struct stat *st)
 		break;
 	}
 
+	/*
+	** Sign and encrypt the message as needed.
+	** Use the mhbuild composition file for the draft if there was
+	** a successful conversion because that now contains the MIME
+	** message.  A nice side effect of this is that it leaves the
+	** original draft file untouched so that it can be retrieved
+	** and modified if desired.
+	*/
+	switch (signandenc(drft)) {
+	case OK:
+		drft = composition_file_name;
+		break;
+
+	case NOTOK:
+		return (NOTOK);
+
+	case DONE:
+		break;
+	}
+
 	done=armed_done;
 	switch (setjmp(env)) {
 	case OK:
@@ -434,6 +455,53 @@ attach(char *draft_file_name)
 	return (OK);
 }
 
+static int
+signandenc(char *draft_file_name)
+{
+	char buf[BUFSIZ];
+	int dosign = 0;
+	int doenc = 0;
+
+	if (!(draft_file = fopen(draft_file_name, "r"))) {
+		adios(NULL, "can't open draft file `%s'.", draft_file_name);
+	}
+
+	/* We'll grow the buffer as needed. */
+	field = (char *)mh_xmalloc(field_size = 256);
+
+	/* Scan the draft file for an attachment header field name. */
+	while (get_line() != EOF && *field != '\0' && *field != '-') {
+		if (strncasecmp(field, sign_hdr, strlen(sign_hdr))==0 &&
+				field[strlen(sign_hdr)] == ':') {
+			dosign = 1;
+		}
+		if (strncasecmp(field, enc_hdr, strlen(enc_hdr))==0 &&
+				field[strlen(enc_hdr)] == ':') {
+			doenc = 1;
+		}
+	}
+	if (!dosign && !doenc) {
+		return DONE;
+	}
+
+	strcpy(composition_file_name, draft_file_name);
+
+	/* We're ready to roll! */
+	sprintf(buf, "mhsign -m%s '%s'", doenc ? " -e" : "",
+			draft_file_name);
+	if (system(buf) != 0) {
+		/* some problem */
+		return (NOTOK);
+	}
+	/* Remove the automatically created backup of mhsign. */
+	snprintf(buf, sizeof buf, "%s.orig", draft_file_name);
+	if (unlink(buf) == -1) {
+		advise(NULL, "unable to remove original draft file.");
+	}
+
+	return (OK);
+}
+
 static void
 clean_up_temporary_files(void)
 {
-- 
1.7.10.4