smime: Pass PKCS#7 envelopedData to node_decrypt_and_verify

[notmuch] / mime-node.c

diff --git a/mime-node.c b/mime-node.c
index 599d3b65e4176598f3376ba0eaf9cbdfd5c32533..f552e03a780f56e0b6926550e52c649bc3f1b792 100644 (file)
--- a/mime-node.c
+++ b/mime-node.c
@@ -36,6 +36,9 @@ typedef struct mime_node_context {
     GMimeMessage *mime_message;
     _notmuch_message_crypto_t *msg_crypto;
 
+    /* repaired/unmangled parts that will need to be cleaned up */
+    GSList *repaired_parts;
+
     /* Context provided by the caller. */
     _notmuch_crypto_t *crypto;
 } mime_node_context_t;
@@ -52,9 +55,21 @@ _mime_node_context_free (mime_node_context_t *res)
     if (res->stream)
        g_object_unref (res->stream);
 
+    if (res->repaired_parts)
+       g_slist_free_full (res->repaired_parts, g_object_unref);
+
     return 0;
 }
 
+/* keep track of objects that need to be destroyed when the mime node
+ * context goes away. */
+static void
+_mime_node_context_track_repaired_part (mime_node_context_t *ctx, GMimeObject *part)
+{
+    if (part)
+       ctx->repaired_parts = g_slist_prepend (ctx->repaired_parts, part);
+}
+
 const _notmuch_message_crypto_t *
 mime_node_get_message_crypto_status (mime_node_t *node)
 {
@@ -177,6 +192,26 @@ set_signature_list_destructor (mime_node_t *node)
     }
 }
 
+/* Unwrapped MIME part destructor */
+static int
+_unwrapped_child_free (GMimeObject **proxy)
+{
+    g_object_unref (*proxy);
+    return 0;
+}
+
+/* Set up unwrapped MIME part destructor */
+static void
+set_unwrapped_child_destructor (mime_node_t *node)
+{
+    GMimeObject **proxy = talloc (node, GMimeObject *);
+
+    if (proxy) {
+       *proxy = node->unwrapped_child;
+       talloc_set_destructor (proxy, _unwrapped_child_free);
+    }
+}
+
 /* Verify a signed mime node */
 static void
 node_verify (mime_node_t *node, GMimeObject *part)
@@ -185,8 +220,17 @@ node_verify (mime_node_t *node, GMimeObject *part)
     notmuch_status_t status;
 
     node->verify_attempted = true;
-    node->sig_list = g_mime_multipart_signed_verify (
-       GMIME_MULTIPART_SIGNED (part), GMIME_ENCRYPT_NONE, &err);
+    if (GMIME_IS_APPLICATION_PKCS7_MIME (part))
+       node->sig_list = g_mime_application_pkcs7_mime_verify (
+           GMIME_APPLICATION_PKCS7_MIME (part), GMIME_VERIFY_NONE, &node->unwrapped_child, &err);
+    else
+       node->sig_list = g_mime_multipart_signed_verify (
+           GMIME_MULTIPART_SIGNED (part), GMIME_VERIFY_NONE, &err);
+
+    if (node->unwrapped_child) {
+       node->nchildren = 1;
+       set_unwrapped_child_destructor (node);
+    }
 
     if (node->sig_list)
        set_signature_list_destructor (node);
@@ -209,22 +253,23 @@ node_decrypt_and_verify (mime_node_t *node, GMimeObject *part)
     GError *err = NULL;
     GMimeDecryptResult *decrypt_result = NULL;
     notmuch_status_t status;
-    GMimeMultipartEncrypted *encrypteddata = GMIME_MULTIPART_ENCRYPTED (part);
     notmuch_message_t *message = NULL;
 
-    if (! node->decrypted_child) {
+    if (! node->unwrapped_child) {
        for (mime_node_t *parent = node; parent; parent = parent->parent)
            if (parent->envelope_file) {
                message = parent->envelope_file;
                break;
            }
 
-       node->decrypted_child = _notmuch_crypto_decrypt (&node->decrypt_attempted,
+       node->unwrapped_child = _notmuch_crypto_decrypt (&node->decrypt_attempted,
                                                         node->ctx->crypto->decrypt,
                                                         message,
-                                                        encrypteddata, &decrypt_result, &err);
+                                                        part, &decrypt_result, &err);
+       if (node->unwrapped_child)
+           set_unwrapped_child_destructor (node);
     }
-    if (! node->decrypted_child) {
+    if (! node->unwrapped_child) {
        fprintf (stderr, "Failed to decrypt part: %s\n",
                 err ? err->message : "no error explanation given");
        goto DONE;
@@ -298,6 +343,13 @@ _mime_node_set_up_part (mime_node_t *node, GMimeObject *part, int numchild)
        node->part = part;
        node->nchildren = 0;
     } else if (GMIME_IS_MULTIPART (part)) {
+       GMimeObject *repaired_part = _notmuch_repair_mixed_up_mangled (part);
+       if (repaired_part) {
+           /* This was likely "Mixed Up" in transit!  We replace it
+            * with the more likely-to-be-correct variant. */
+           _mime_node_context_track_repaired_part (node->ctx, repaired_part);
+           part = repaired_part;
+       }
        node->part = part;
        node->nchildren = g_mime_multipart_get_count (GMIME_MULTIPART (part));
     } else if (GMIME_IS_MESSAGE_PART (part)) {
@@ -332,6 +384,18 @@ _mime_node_set_up_part (mime_node_t *node, GMimeObject *part, int numchild)
        } else {
            node_verify (node, part);
        }
+    } else if (GMIME_IS_APPLICATION_PKCS7_MIME (part) &&
+              GMIME_SECURE_MIME_TYPE_SIGNED_DATA == g_mime_application_pkcs7_mime_get_smime_type (GMIME_APPLICATION_PKCS7_MIME (part))) {
+       /* If node->ctx->crypto->verify is false, it would be better
+        * to just unwrap (instead of verifying), but
+        * https://github.com/jstedfast/gmime/issues/67 */
+       node_verify (node, part);
+    } else if (GMIME_IS_APPLICATION_PKCS7_MIME (part) &&
+              GMIME_SECURE_MIME_TYPE_ENVELOPED_DATA == g_mime_application_pkcs7_mime_get_smime_type (GMIME_APPLICATION_PKCS7_MIME (part)) &&
+              (node->ctx->crypto->decrypt != NOTMUCH_DECRYPT_FALSE)) {
+       node_decrypt_and_verify (node, part);
+       if (node->unwrapped_child && node->nchildren == 0)
+           node->nchildren = 1;
     } else {
        if (_notmuch_message_crypto_potential_payload (node->ctx->msg_crypto, part, node->parent ? node->parent->part : NULL, numchild) &&
            node->ctx->msg_crypto->decryption_status == NOTMUCH_MESSAGE_DECRYPTED_FULL) {
@@ -358,13 +422,17 @@ mime_node_child (mime_node_t *parent, int child)
        return NULL;
 
     if (GMIME_IS_MULTIPART (parent->part)) {
-       if (child == GMIME_MULTIPART_ENCRYPTED_CONTENT && parent->decrypted_child)
-           sub = parent->decrypted_child;
+       if (child == GMIME_MULTIPART_ENCRYPTED_CONTENT && parent->unwrapped_child)
+           sub = parent->unwrapped_child;
        else
            sub = g_mime_multipart_get_part (
                GMIME_MULTIPART (parent->part), child);
     } else if (GMIME_IS_MESSAGE (parent->part)) {
        sub = g_mime_message_get_mime_part (GMIME_MESSAGE (parent->part));
+    } else if (GMIME_IS_APPLICATION_PKCS7_MIME (parent->part) &&
+              parent->unwrapped_child &&
+              child == 0) {
+       sub = parent->unwrapped_child;
     } else {
        /* This should have been caught by _mime_node_set_up_part */
        INTERNAL_ERROR ("Unexpected GMimeObject type: %s",