[gmime] Don't set the passphrase cb until we need it

[Jeffrey Stedfast <fejj src gnome org>]

commit 6e1c4ba037371c1aec6c6683cc295978aa8d5309
Author: Jeffrey Stedfast <jestedfa microsoft com>
Date:   Tue Mar 14 18:37:24 2017 -0400

    Don't set the passphrase cb until we need it
    
    This also means that we won't accidentally trick gpgme
    into calling our passphrase callback if the user-supplied
    callback is NULL.

 gmime/gmime-gpg-context.c   |   41 ++++++++++++++++++++++++++++++++++-------
 gmime/gmime-gpgme-utils.c   |   12 ++++--------
 gmime/gmime-pkcs7-context.c |   28 ++++++++++++++++++++++------
 3 files changed, 60 insertions(+), 21 deletions(-)
---
diff --git a/gmime/gmime-gpg-context.c b/gmime/gmime-gpg-context.c
index d534561..f75f519 100644
--- a/gmime/gmime-gpg-context.c
+++ b/gmime/gmime-gpg-context.c
@@ -263,6 +263,17 @@ gpg_get_key_exchange_protocol (GMimeCryptoContext *ctx)
        return "application/pgp-keys";
 }
 
+static void
+set_passphrase_callback (GMimeCryptoContext *context)
+{
+       GMimeGpgContext *gpg = (GMimeGpgContext *) context;
+       
+       if (context->request_passwd)
+               gpgme_set_passphrase_cb (gpg->ctx, g_mime_gpgme_passphrase_callback, gpg);
+       else
+               gpgme_set_passphrase_cb (gpg->ctx, NULL, NULL);
+}
+
 static int
 gpg_sign (GMimeCryptoContext *context, gboolean detach, const char *userid,
          GMimeStream *istream, GMimeStream *ostream, GError **err)
@@ -271,11 +282,14 @@ gpg_sign (GMimeCryptoContext *context, gboolean detach, const char *userid,
        gpgme_sig_mode_t mode = detach ? GPGME_SIG_MODE_DETACH : GPGME_SIG_MODE_CLEAR;
        GMimeGpgContext *gpg = (GMimeGpgContext *) context;
        
+       set_passphrase_callback (context);
+       
        gpgme_set_textmode (gpg->ctx, !detach);
        
        return g_mime_gpgme_sign (gpg->ctx, mode, userid, istream, ostream, err);
 #else
-       g_set_error_literal (err, GMIME_ERROR, GMIME_ERROR_NOT_SUPPORTED, _("PGP support is not enabled in 
this build"));
+       g_set_error_literal (err, GMIME_ERROR, GMIME_ERROR_NOT_SUPPORTED,
+                            _("PGP support is not enabled in this build"));
        
        return -1;
 #endif /* ENABLE_CRYPTO */
@@ -290,7 +304,8 @@ gpg_verify (GMimeCryptoContext *context, GMimeVerifyFlags flags, GMimeStream *is
        
        return g_mime_gpgme_verify (gpg->ctx, flags, istream, sigstream, ostream, err);
 #else
-       g_set_error_literal (err, GMIME_ERROR, GMIME_ERROR_NOT_SUPPORTED, _("PGP support is not enabled in 
this build"));
+       g_set_error_literal (err, GMIME_ERROR, GMIME_ERROR_NOT_SUPPORTED,
+                            _("PGP support is not enabled in this build"));
        
        return NULL;
 #endif /* ENABLE_CRYPTO */
@@ -303,9 +318,13 @@ gpg_encrypt (GMimeCryptoContext *context, gboolean sign, const char *userid, GMi
 #ifdef ENABLE_CRYPTO
        GMimeGpgContext *gpg = (GMimeGpgContext *) context;
        
+       if (sign)
+               set_passphrase_callback (context);
+       
        return g_mime_gpgme_encrypt (gpg->ctx, sign, userid, flags, recipients, istream, ostream, err);
 #else
-       g_set_error_literal (err, GMIME_ERROR, GMIME_ERROR_NOT_SUPPORTED, _("PGP support is not enabled in 
this build"));
+       g_set_error_literal (err, GMIME_ERROR, GMIME_ERROR_NOT_SUPPORTED,
+                            _("PGP support is not enabled in this build"));
        
        return -1;
 #endif /* ENABLE_CRYPTO */
@@ -318,9 +337,12 @@ gpg_decrypt (GMimeCryptoContext *context, GMimeDecryptFlags flags, const char *s
 #ifdef ENABLE_CRYPTO
        GMimeGpgContext *gpg = (GMimeGpgContext *) context;
        
+       set_passphrase_callback (context);
+       
        return g_mime_gpgme_decrypt (gpg->ctx, flags, session_key, istream, ostream, err);
 #else
-       g_set_error_literal (err, GMIME_ERROR, GMIME_ERROR_NOT_SUPPORTED, _("PGP support is not enabled in 
this build"));
+       g_set_error_literal (err, GMIME_ERROR, GMIME_ERROR_NOT_SUPPORTED,
+                            _("PGP support is not enabled in this build"));
        
        return NULL;
 #endif /* ENABLE_CRYPTO */
@@ -332,9 +354,12 @@ gpg_import_keys (GMimeCryptoContext *context, GMimeStream *istream, GError **err
 #ifdef ENABLE_CRYPTO
        GMimeGpgContext *gpg = (GMimeGpgContext *) context;
        
+       set_passphrase_callback (context);
+       
        return g_mime_gpgme_import (gpg->ctx, istream, err);
 #else
-       g_set_error_literal (err, GMIME_ERROR, GMIME_ERROR_NOT_SUPPORTED, _("PGP support is not enabled in 
this build"));
+       g_set_error_literal (err, GMIME_ERROR, GMIME_ERROR_NOT_SUPPORTED,
+                            _("PGP support is not enabled in this build"));
        
        return -1;
 #endif /* ENABLE_CRYPTO */
@@ -346,9 +371,12 @@ gpg_export_keys (GMimeCryptoContext *context, const char *keys[], GMimeStream *o
 #ifdef ENABLE_CRYPTO
        GMimeGpgContext *gpg = (GMimeGpgContext *) context;
        
+       set_passphrase_callback (context);
+       
        return g_mime_gpgme_export (gpg->ctx, keys, ostream, err);
 #else
-       g_set_error_literal (err, GMIME_ERROR, GMIME_ERROR_NOT_SUPPORTED, _("PGP support is not enabled in 
this build"));
+       g_set_error_literal (err, GMIME_ERROR, GMIME_ERROR_NOT_SUPPORTED,
+                            _("PGP support is not enabled in this build"));
        
        return -1;
 #endif /* ENABLE_CRYPTO */
@@ -378,7 +406,6 @@ g_mime_gpg_context_new (void)
                return NULL;
        
        gpg = g_object_newv (GMIME_TYPE_GPG_CONTEXT, 0, NULL);
-       gpgme_set_passphrase_cb (ctx, g_mime_gpgme_passphrase_callback, gpg);
        gpgme_set_protocol (ctx, GPGME_PROTOCOL_OpenPGP);
        gpgme_set_armor (ctx, TRUE);
        gpg->ctx = ctx;
diff --git a/gmime/gmime-gpgme-utils.c b/gmime/gmime-gpgme-utils.c
index a325019..bf03bb8 100644
--- a/gmime/gmime-gpgme-utils.c
+++ b/gmime/gmime-gpgme-utils.c
@@ -81,14 +81,10 @@ g_mime_gpgme_passphrase_callback (void *hook, const char *uid_hint, const char *
        GError *err = NULL;
        gboolean rv;
        
-       if (context->request_passwd) {
-               stream = g_mime_stream_pipe_new (fd);
-               g_mime_stream_pipe_set_owner ((GMimeStreamPipe *) stream, FALSE);
-               rv = context->request_passwd (context, uid_hint, passphrase_info, prev_was_bad, stream, &err);
-               g_object_unref (stream);
-       } else {
-               return GPG_ERR_GENERAL;
-       }
+       stream = g_mime_stream_pipe_new (fd);
+       g_mime_stream_pipe_set_owner ((GMimeStreamPipe *) stream, FALSE);
+       rv = context->request_passwd (context, uid_hint, passphrase_info, prev_was_bad, stream, &err);
+       g_object_unref (stream);
        
        if (!rv) {
                error = GPG_ERR_CANCELED;
diff --git a/gmime/gmime-pkcs7-context.c b/gmime/gmime-pkcs7-context.c
index 80b6b30..15b6292 100644
--- a/gmime/gmime-pkcs7-context.c
+++ b/gmime/gmime-pkcs7-context.c
@@ -259,6 +259,8 @@ pkcs7_get_key_exchange_protocol (GMimeCryptoContext *ctx)
        return "application/pkcs7-keys";
 }
 
+#define set_passphrase_callback(context)
+
 static int
 pkcs7_sign (GMimeCryptoContext *context, gboolean detach, const char *userid,
            GMimeStream *istream, GMimeStream *ostream, GError **err)
@@ -267,9 +269,12 @@ pkcs7_sign (GMimeCryptoContext *context, gboolean detach, const char *userid,
        gpgme_sig_mode_t mode = detach ? GPGME_SIG_MODE_DETACH : GPGME_SIG_MODE_NORMAL;
        GMimePkcs7Context *pkcs7 = (GMimePkcs7Context *) context;
        
+       set_passphrase_callback (context);
+       
        return g_mime_gpgme_sign (pkcs7->ctx, mode, userid, istream, ostream, err);
 #else
-       g_set_error_literal (err, GMIME_ERROR, GMIME_ERROR_NOT_SUPPORTED, _("S/MIME support is not enabled in 
this build"));
+       g_set_error_literal (err, GMIME_ERROR, GMIME_ERROR_NOT_SUPPORTED,
+                            _("S/MIME support is not enabled in this build"));
        
        return -1;
 #endif /* ENABLE_CRYPTO */
@@ -284,7 +289,8 @@ pkcs7_verify (GMimeCryptoContext *context, GMimeVerifyFlags flags, GMimeStream *
        
        return g_mime_gpgme_verify (pkcs7->ctx, flags, istream, sigstream, ostream, err);
 #else
-       g_set_error_literal (err, GMIME_ERROR, GMIME_ERROR_NOT_SUPPORTED, _("S/MIME support is not enabled in 
this build"));
+       g_set_error_literal (err, GMIME_ERROR, GMIME_ERROR_NOT_SUPPORTED,
+                            _("S/MIME support is not enabled in this build"));
        
        return NULL;
 #endif /* ENABLE_CRYPTO */
@@ -305,7 +311,8 @@ pkcs7_encrypt (GMimeCryptoContext *context, gboolean sign, const char *userid, G
        
        return g_mime_gpgme_encrypt (pkcs7->ctx, sign, userid, flags, recipients, istream, ostream, err);
 #else
-       g_set_error_literal (err, GMIME_ERROR, GMIME_ERROR_NOT_SUPPORTED, _("S/MIME support is not enabled in 
this build"));
+       g_set_error_literal (err, GMIME_ERROR, GMIME_ERROR_NOT_SUPPORTED,
+                            _("S/MIME support is not enabled in this build"));
        
        return -1;
 #endif /* ENABLE_CRYPTO */
@@ -318,9 +325,12 @@ pkcs7_decrypt (GMimeCryptoContext *context, GMimeDecryptFlags flags, const char
 #ifdef ENABLE_CRYPTO
        GMimePkcs7Context *pkcs7 = (GMimePkcs7Context *) context;
        
+       set_passphrase_callback (context);
+       
        return g_mime_gpgme_decrypt (pkcs7->ctx, flags, session_key, istream, ostream, err);
 #else
-       g_set_error_literal (err, GMIME_ERROR, GMIME_ERROR_NOT_SUPPORTED, _("S/MIME support is not enabled in 
this build"));
+       g_set_error_literal (err, GMIME_ERROR, GMIME_ERROR_NOT_SUPPORTED,
+                            _("S/MIME support is not enabled in this build"));
        
        return NULL;
 #endif /* ENABLE_CRYPTO */
@@ -332,9 +342,12 @@ pkcs7_import_keys (GMimeCryptoContext *context, GMimeStream *istream, GError **e
 #ifdef ENABLE_CRYPTO
        GMimePkcs7Context *pkcs7 = (GMimePkcs7Context *) context;
        
+       set_passphrase_callback (context);
+       
        return g_mime_gpgme_import (pkcs7->ctx, istream, err);
 #else
-       g_set_error_literal (err, GMIME_ERROR, GMIME_ERROR_NOT_SUPPORTED, _("S/MIME support is not enabled in 
this build"));
+       g_set_error_literal (err, GMIME_ERROR, GMIME_ERROR_NOT_SUPPORTED,
+                            _("S/MIME support is not enabled in this build"));
        
        return -1;
 #endif /* ENABLE_CRYPTO */
@@ -346,9 +359,12 @@ pkcs7_export_keys (GMimeCryptoContext *context, const char *keys[], GMimeStream
 #ifdef ENABLE_CRYPTO
        GMimePkcs7Context *pkcs7 = (GMimePkcs7Context *) context;
        
+       set_passphrase_callback (context);
+       
        return g_mime_gpgme_export (pkcs7->ctx, keys, ostream, err);
 #else
-       g_set_error_literal (err, GMIME_ERROR, GMIME_ERROR_NOT_SUPPORTED, _("S/MIME support is not enabled in 
this build"));
+       g_set_error_literal (err, GMIME_ERROR, GMIME_ERROR_NOT_SUPPORTED,
+                            _("S/MIME support is not enabled in this build"));
        
        return -1;
 #endif /* ENABLE_CRYPTO */