[evolution-data-server] I#3 - [GPG] Mails that are not encrypted look encrypted

[Milan Crha <mcrha src gnome org>]

commit 93306a296c64b48d12c356804f131048643eaa0a
Author: Milan Crha <mcrha redhat com>
Date:   Thu Jun 28 16:19:58 2018 +0200

    I#3 - [GPG] Mails that are not encrypted look encrypted
    
    Closes https://gitlab.gnome.org/GNOME/evolution-data-server/issues/3

 src/camel/camel-gpg-context.c | 41 +++++++++++++++++++++++++++++++++--------
 1 file changed, 33 insertions(+), 8 deletions(-)
---
diff --git a/src/camel/camel-gpg-context.c b/src/camel/camel-gpg-context.c
index e55723d8e..0af41e411 100644
--- a/src/camel/camel-gpg-context.c
+++ b/src/camel/camel-gpg-context.c
@@ -145,6 +145,8 @@ struct _GpgCtx {
        gchar *photos_filename;
        gchar *viewer_cmd;
 
+       GString *decrypt_extra_text; /* Text received during decryption, which is in the blob, but is not 
encrypted */
+
        gint exit_status;
 
        guint exited : 1;
@@ -171,6 +173,7 @@ struct _GpgCtx {
        guint trust : 3;
        guint processing : 1;
        guint bad_decrypt : 1;
+       guint in_decrypt_stage : 1;
        guint noseckey : 1;
        GString *signers;
        GHashTable *signers_keyid;
@@ -241,12 +244,14 @@ gpg_ctx_new (CamelCipherContext *context)
        gpg->trust = GPG_TRUST_NONE;
        gpg->processing = FALSE;
        gpg->bad_decrypt = FALSE;
+       gpg->in_decrypt_stage = FALSE;
        gpg->noseckey = FALSE;
        gpg->signers = NULL;
        gpg->signers_keyid = g_hash_table_new_full (g_str_hash, g_str_equal, g_free, g_free);
 
        gpg->istream = NULL;
        gpg->ostream = NULL;
+       gpg->decrypt_extra_text = NULL;
 
        gpg->diagbuf = g_byte_array_new ();
        gpg->diagflushed = FALSE;
@@ -504,6 +509,9 @@ gpg_ctx_free (struct _GpgCtx *gpg)
        g_free (gpg->photos_filename);
        g_free (gpg->viewer_cmd);
 
+       if (gpg->decrypt_extra_text)
+               g_string_free (gpg->decrypt_extra_text, TRUE);
+
        g_free (gpg);
 }
 
@@ -1188,10 +1196,12 @@ gpg_ctx_parse_status (struct _GpgCtx *gpg,
                case GPG_CTX_MODE_DECRYPT:
                        if (!strncmp ((gchar *) status, "BEGIN_DECRYPTION", 16)) {
                                gpg->bad_decrypt = FALSE;
-                               /* nothing to do... but we know to expect data on stdout soon */
+                               /* Mark it's expected to get decrypted data on stdout */
+                               gpg->in_decrypt_stage = TRUE;
                                break;
                        } else if (!strncmp ((gchar *) status, "END_DECRYPTION", 14)) {
-                               /* nothing to do, but we know the end is near? */
+                               /* Mark to no longer expect decrypted data */
+                               gpg->in_decrypt_stage = FALSE;
                                break;
                        } else if (!strncmp ((gchar *) status, "NO_SECKEY ", 10)) {
                                gpg->noseckey = TRUE;
@@ -1428,11 +1438,18 @@ gpg_ctx_op_step (struct _GpgCtx *gpg,
                        goto exception;
 
                if (nread > 0) {
-                       gsize written = camel_stream_write (
-                               gpg->ostream, buffer, (gsize)
-                               nread, cancellable, error);
-                       if (written != nread)
-                               return -1;
+                       if (gpg->mode != GPG_CTX_MODE_DECRYPT ||
+                           gpg->in_decrypt_stage) {
+                               gsize written = camel_stream_write (
+                                       gpg->ostream, buffer, (gsize)
+                                       nread, cancellable, error);
+                               if (written != nread)
+                                       return -1;
+                       } else {
+                               if (!gpg->decrypt_extra_text)
+                                       gpg->decrypt_extra_text = g_string_new ("");
+                               g_string_append_len (gpg->decrypt_extra_text, buffer, nread);
+                       }
                } else {
                        gpg->seen_eof1 = TRUE;
                }
@@ -2649,6 +2666,11 @@ gpg_decrypt_sync (CamelCipherContext *context,
                goto fail;
        }
 
+       /* Decrypted nothing, write at least CRLF */
+       if (!g_seekable_tell (G_SEEKABLE (ostream))) {
+               g_warn_if_fail (2 == camel_stream_write (ostream, "\r\n", 2, cancellable, NULL));
+       }
+
        g_seekable_seek (G_SEEKABLE (ostream), 0, G_SEEK_SET, NULL, NULL);
 
        if (gpg->bad_decrypt && gpg->noseckey) {
@@ -2691,7 +2713,10 @@ gpg_decrypt_sync (CamelCipherContext *context,
 
        if (success) {
                valid = camel_cipher_validity_new ();
-               valid->encrypt.description = g_strdup (_("Encrypted content"));
+               if (gpg->decrypt_extra_text)
+                       valid->encrypt.description = g_strdup_printf (_("GPG blob contains unencrypted text: 
%s"), gpg->decrypt_extra_text->str);
+               else
+                       valid->encrypt.description = g_strdup (_("Encrypted content"));
                valid->encrypt.status = CAMEL_CIPHER_VALIDITY_ENCRYPT_ENCRYPTED;
 
                if (gpg->hadsig) {