[evolution-data-server] [CamelGpgContext] Handle decryption failures better

[Milan Crha <mcrha src gnome org>]

commit c503160e5bf1ab3ad692f051503b789bb28cad1f
Author: Milan Crha <mcrha redhat com>
Date:   Mon Jun 22 21:19:19 2015 +0200

    [CamelGpgContext] Handle decryption failures better
    
    The failure could be ignored and a 0-length output part could be
    returned, which is wrong.

 camel/camel-gpg-context.c |   27 ++++++++++++++++++++++++---
 1 files changed, 24 insertions(+), 3 deletions(-)
---
diff --git a/camel/camel-gpg-context.c b/camel/camel-gpg-context.c
index 72c6d93..631d78a 100644
--- a/camel/camel-gpg-context.c
+++ b/camel/camel-gpg-context.c
@@ -161,6 +161,8 @@ struct _GpgCtx {
        guint nodata : 1;
        guint trust : 3;
        guint processing : 1;
+       guint bad_decrypt : 1;
+       guint noseckey : 1;
        GString *signers;
 
        guint diagflushed : 1;
@@ -224,6 +226,8 @@ gpg_ctx_new (CamelCipherContext *context)
        gpg->nopubkey = FALSE;
        gpg->trust = GPG_TRUST_NONE;
        gpg->processing = FALSE;
+       gpg->bad_decrypt = FALSE;
+       gpg->noseckey = FALSE;
        gpg->signers = NULL;
 
        gpg->istream = NULL;
@@ -1030,11 +1034,18 @@ gpg_ctx_parse_status (struct _GpgCtx *gpg,
                        break;
                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 */
                                break;
                        } else if (!strncmp ((gchar *) status, "END_DECRYPTION", 14)) {
                                /* nothing to do, but we know the end is near? */
                                break;
+                       } else if (!strncmp ((gchar *) status, "NO_SECKEY ", 10)) {
+                               gpg->noseckey = TRUE;
+                               break;
+                       } else if (!strncmp ((gchar *) status, "DECRYPTION_FAILED", 17)) {
+                               gpg->bad_decrypt = TRUE;
+                               break;
                        }
                        /* let if fall through to verify possible signatures too */
                        /* break; */
@@ -1245,6 +1256,7 @@ gpg_ctx_op_step (struct _GpgCtx *gpg,
 
                do {
                        nread = read (gpg->status_fd, buffer, sizeof (buffer));
+                       d (printf ("   read %d bytes (%.*s)\n", (gint) nread, (gint) nread, buffer));
                } while (nread == -1 && (errno == EINTR || errno == EAGAIN));
                if (nread == -1)
                        goto exception;
@@ -1267,6 +1279,7 @@ gpg_ctx_op_step (struct _GpgCtx *gpg,
 
                do {
                        nread = read (gpg->stdout_fd, buffer, sizeof (buffer));
+                       d (printf ("   read %d bytes (%.*s)\n", (gint) nread, (gint) nread, buffer));
                } while (nread == -1 && (errno == EINTR || errno == EAGAIN));
                if (nread == -1)
                        goto exception;
@@ -1292,6 +1305,7 @@ gpg_ctx_op_step (struct _GpgCtx *gpg,
 
                do {
                        nread = read (gpg->stderr_fd, buffer, sizeof (buffer));
+                       d (printf ("   read %d bytes (%.*s)\n", (gint) nread, (gint) nread, buffer));
                } while (nread == -1 && (errno == EINTR || errno == EAGAIN));
                if (nread == -1)
                        goto exception;
@@ -1358,7 +1372,7 @@ gpg_ctx_op_step (struct _GpgCtx *gpg,
                        if (w == -1)
                                goto exception;
 
-                       d (printf ("wrote %d (out of %d) bytes to gpg's stdin\n", nwritten, nread));
+                       d (printf ("wrote %d (out of %d) bytes to gpg's stdin\n", (gint) nwritten, (gint) 
nread));
                        wrote_data = TRUE;
                }
 
@@ -2158,6 +2172,8 @@ gpg_decrypt_sync (CamelCipherContext *context,
        gpg_ctx_set_istream (gpg, istream);
        gpg_ctx_set_ostream (gpg, ostream);
 
+       gpg->bad_decrypt = TRUE;
+
        if (!gpg_ctx_op_start (gpg, error))
                goto fail;
 
@@ -2172,7 +2188,7 @@ gpg_decrypt_sync (CamelCipherContext *context,
         * for signature of a signed and encrypted messages causes GPG to return
         * failure, thus count with it.
         */
-       if (gpg_ctx_op_wait (gpg) != 0 && gpg->nodata) {
+       if (gpg_ctx_op_wait (gpg) != 0 && (gpg->nodata || (gpg->bad_decrypt && !gpg->noseckey))) {
                const gchar *diagnostics;
 
                diagnostics = gpg_ctx_get_diagnostics (gpg);
@@ -2185,7 +2201,12 @@ gpg_decrypt_sync (CamelCipherContext *context,
 
        g_seekable_seek (G_SEEKABLE (ostream), 0, G_SEEK_SET, NULL, NULL);
 
-       if (camel_content_type_is (ct, "multipart", "encrypted")) {
+       if (gpg->bad_decrypt && gpg->noseckey) {
+               success = FALSE;
+               g_set_error (
+                       error, CAMEL_ERROR, CAMEL_ERROR_GENERIC,
+                       _("Failed to decrypt MIME part: Secret key not found"));
+       } else if (camel_content_type_is (ct, "multipart", "encrypted")) {
                CamelDataWrapper *dw;
                CamelStream *null = camel_stream_null_new ();