Implement GPG signing of the outgoing notifications.

* src/config.c (mail_statistics_kw): New keyword gpg-sign.
(notify_event_kw): Likewise.
(wydawca_kw): New keyword gpg-homedir.
* src/gpg.c (wydawca_gpg_homedir): Rename to
create_gpg_homedir. Make static.
All uses updated.
* src/mail.c (admin_stat_sign_key): New global.
(mu_stream_data_read_cb)
(gpg_sign, sign_message): New functions.
(mail_send_message): Take 3rd argument: ID of
the PGP key to sign the message with.
All callers updated.
(do_notify): Rewrite.
* src/wydawca.c (wydawca_gpg_homedir): New variable.
* src/wydawca.h (struct notification): New member
sign_keys.
(admin_stat_sign_key): New extern.
(wydawca_gpg_homedir): New extern.

1 files changed, 222 insertions, 22 deletions

diff --git a/src/mail.c b/src/mail.c
index 91ea502..15c2937 100644
--- a/src/mail.c
+++ b/src/mail.c
@@ -17,6 +17,7 @@
 #include "wydawca.h"
 #include <mail.h>
 #include <hash.h>
+#include <gpgme.h>
 
 int mailer_opened;
 mu_mailer_t mailer;
@@ -27,6 +28,7 @@ unsigned long owner_notification_flags;
 char *user_message_template[MAX_EVENT];
 
 char *admin_stat_message;
+char *admin_stat_sign_key;
 
 void
 mail_init ()
@@ -44,8 +46,203 @@ mail_init ()
     }
 }
 
+struct mu_stream_handle
+{
+  mu_stream_t str;
+  mu_off_t off;
+};
+
+static ssize_t
+mu_stream_data_read_cb (void *handle, void *buffer, size_t size)
+{
+  struct mu_stream_handle *mhp = handle;
+  size_t nread;
+  int rc;
+
+  rc = mu_stream_read (mhp->str, buffer, size, mhp->off, &nread);
+  if (rc)
+    {
+      logmsg (LOG_ERR, "mu_stream_read: %s", mu_strerror (rc));
+      errno = EIO;
+      return -1;
+    }
+
+  mhp->off += nread;
+  return nread;
+}
+
+static int
+gpg_sign (gpgme_data_t *output, gpgme_data_t input, const char *sign_keys)
+{
+  gpgme_ctx_t ctx;
+  gpgme_error_t err = 0;
+  gpgme_key_t key;
+
+  err = gpgme_new (&ctx);
+  if (err)
+    {
+      logmsg (LOG_ERR, _("GPGME: cannot create context: %s"),
+              gpgme_strerror (err));
+      return 1;
+    }
+  
+  err = gpgme_op_keylist_start (ctx, sign_keys, 0);
+  if (!err)
+    {
+      while ((err = gpgme_op_keylist_next (ctx, &key)) == 0)
+        {
+          err = gpgme_signers_add (ctx, key);
+          gpgme_key_release (key);
+        }
+    }
+
+  if (err && gpg_err_code (err) != GPG_ERR_EOF)
+    {
+      logmsg (LOG_ERR, _("GPGME: cannot list keys: %s"),
+              gpgme_strerror (err));
+      gpgme_release (ctx);
+      return 1;
+    }
+
+  err = gpgme_data_new (output);
+  if (err)
+    {
+      logmsg (LOG_ERR, _("%s: GPGME error: %s"),
+              "gpgme_data_new",
+              gpgme_strerror (err));
+      gpgme_release (ctx);
+      return 1;
+    }
+  
+  /* FIXME: Passphrase */
+  gpgme_set_textmode (ctx, 1);
+  gpgme_set_armor (ctx, 1);
+
+  err = gpgme_op_sign (ctx, input, *output, GPGME_SIG_MODE_CLEAR);
+  if (err)
+    logmsg (LOG_ERR, _("%s: GPGME error: %s"),
+            "gpgme_op_sign",
+            gpgme_strerror (err));
+#if 0
+  /* FIXME: */
+  else if (debug_level > 1)
+    gpgme_debug_info (ctx);
+#endif
+
+  gpgme_release (ctx);
+  return err != 0;
+}
+
+static int
+sign_message (mu_message_t *pmsg, const char *key)
+{
+  mu_message_t msg = *pmsg;
+  mu_message_t newmsg;
+  mu_body_t body;
+  mu_header_t hdr;
+  struct mu_stream_handle mhn;
+  mu_stream_t istr, ostr;
+  int rc;
+  struct gpgme_data_cbs cbs;
+  gpgme_data_t input, output;
+  gpgme_error_t err;
+  char *buf = NULL;
+  size_t size = 0;
+  size_t nread;
+
+  if (debug_level)
+    logmsg (LOG_DEBUG, _("signing message as %s"), key);
+  
+  if (wydawca_gpg_homedir)
+    {
+      if (debug_level > 1)
+        logmsg (LOG_DEBUG, _("setting GNUPG home directory: %s"),
+                wydawca_gpg_homedir);
+      setenv ("GNUPGHOME", wydawca_gpg_homedir, 1);
+    }
+  
+  if ((rc = mu_message_get_body (msg, &body)))
+    {
+      logmsg (LOG_ERR, "mu_message_get_body: %s", mu_strerror (rc));
+      return 1;
+    }
+
+  if ((rc = mu_body_get_stream (body, &mhn.str)))
+    {
+      logmsg (LOG_ERR, "mu_message_get_stream: %s", mu_strerror (rc));
+      return 1;
+    }
+
+  mu_stream_seek (mhn.str, 0, SEEK_SET);
+  mhn.off = 0;
+
+  memset (&cbs, 0, sizeof (cbs));
+  cbs.read = mu_stream_data_read_cb;
+
+  err = gpgme_data_new_from_cbs (&input, &cbs, &mhn);
+  if (err)
+    {
+      logmsg (LOG_ERR, "gpgme_data_new_from_cbs: %s",
+              gpgme_strerror (rc));
+      return 1;
+    }
+
+  rc = gpg_sign (&output, input, key);
+
+  if (gpgme_data_seek (output, 0, SEEK_SET) == -1)
+    {
+      logmsg (LOG_ERR, "gpgme_data_seek: %s", strerror (errno));
+      return 1;
+    }
+      
+  mu_message_create (&newmsg, NULL);
+  mu_message_get_stream (newmsg, &ostr);
+
+  /* Copy headers */
+  mu_message_get_header (msg, &hdr);
+  mu_header_get_stream (hdr, &istr);
+  mu_stream_seek (istr, 0, SEEK_SET);
+  while ((rc = mu_stream_sequential_getline (istr, &buf, &size, &nread)) == 0
+         && nread)
+    {
+      rc = mu_stream_sequential_write (ostr, buf, nread);
+      if (rc)
+        {
+          logmsg (LOG_ERR, "mu_stream_sequential_write: %s",
+                  mu_strerror (rc));
+          break;
+        }
+    }
+
+  if (rc == 0)
+    {
+      while ((nread = gpgme_data_read (output, buf, size)) > 0)
+        {
+          rc = mu_stream_sequential_write (ostr, buf, nread);
+          if (rc)
+            {
+              logmsg (LOG_ERR, "mu_stream_sequential_write: %s",
+                      mu_strerror (rc));
+              break;
+            }
+        }
+
+      if (rc == 0)
+        {
+          mu_message_destroy (&msg, mu_message_get_owner (msg));
+          *pmsg = newmsg;
+        }
+    }
+  
+  gpgme_data_release (output);
+  free (buf);
+
+  return rc;
+}
+
 void
-mail_send_message (mu_address_t rcpt, const char *text)
+mail_send_message (mu_address_t rcpt, const char *text,
+                   const char *signer_key)
 {
   int rc;
   mu_message_t msg;
@@ -91,7 +288,7 @@ mail_send_message (mu_address_t rcpt, const char *text)
       if (debug_level > 2)
         mailer_flags = MAILER_FLAG_DEBUG_DATA;
     }
-
+  
   if (!mailer_opened)
     {
       if ((rc = mu_mailer_open (mailer, mailer_flags)))
@@ -106,10 +303,16 @@ mail_send_message (mu_address_t rcpt, const char *text)
       mailer_opened = 1;
     }
 
-  rc = mu_mailer_send_message (mailer, msg, from_address, rcpt);
-  if (rc)
-    logmsg (LOG_CRIT, _("cannot send message: %s"), mu_strerror (rc));
+  if (signer_key)
+    sign_message (&msg, signer_key);
+