crypto: move into libnotmuch_util

[notmuch] / util / crypto.c

diff --git a/util/crypto.c b/util/crypto.c
new file mode 100644 (file)
index 0000000..c51d67e
--- /dev/null
+++ b/util/crypto.c
@@ -0,0 +1,142 @@
+/* notmuch - Not much of an email program, (just index and search)
+ *
+ * Copyright © 2012 Jameson Rollins
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see https://www.gnu.org/licenses/ .
+ *
+ * Authors: Jameson Rollins <jrollins@finestructure.net>
+ */
+
+#include "crypto.h"
+#include <strings.h>
+#define unused(x) x __attribute__ ((unused))
+
+#define ARRAY_SIZE(arr) (sizeof (arr) / sizeof (arr[0]))
+
+#if (GMIME_MAJOR_VERSION < 3)
+/* Create a GPG context (GMime 2.6) */
+static GMimeCryptoContext *
+create_gpg_context (_notmuch_crypto_t *crypto)
+{
+    GMimeCryptoContext *gpgctx;
+
+    if (crypto->gpgctx)
+       return crypto->gpgctx;
+
+    /* TODO: GMimePasswordRequestFunc */
+    gpgctx = g_mime_gpg_context_new (NULL, crypto->gpgpath ? crypto->gpgpath : "gpg");
+    if (! gpgctx) {
+       fprintf (stderr, "Failed to construct gpg context.\n");
+       return NULL;
+    }
+    crypto->gpgctx = gpgctx;
+
+    g_mime_gpg_context_set_use_agent ((GMimeGpgContext *) gpgctx, true);
+    g_mime_gpg_context_set_always_trust ((GMimeGpgContext *) gpgctx, false);
+
+    return gpgctx;
+}
+
+/* Create a PKCS7 context (GMime 2.6) */
+static GMimeCryptoContext *
+create_pkcs7_context (_notmuch_crypto_t *crypto)
+{
+    GMimeCryptoContext *pkcs7ctx;
+
+    if (crypto->pkcs7ctx)
+       return crypto->pkcs7ctx;
+
+    /* TODO: GMimePasswordRequestFunc */
+    pkcs7ctx = g_mime_pkcs7_context_new (NULL);
+    if (! pkcs7ctx) {
+       fprintf (stderr, "Failed to construct pkcs7 context.\n");
+       return NULL;
+    }
+    crypto->pkcs7ctx = pkcs7ctx;
+
+    g_mime_pkcs7_context_set_always_trust ((GMimePkcs7Context *) pkcs7ctx,
+                                          false);
+
+    return pkcs7ctx;
+}
+static const struct {
+    const char *protocol;
+    GMimeCryptoContext *(*get_context) (_notmuch_crypto_t *crypto);
+} protocols[] = {
+    {
+       .protocol = "application/pgp-signature",
+       .get_context = create_gpg_context,
+    },
+    {
+       .protocol = "application/pgp-encrypted",
+       .get_context = create_gpg_context,
+    },
+    {
+       .protocol = "application/pkcs7-signature",
+       .get_context = create_pkcs7_context,
+    },
+    {
+       .protocol = "application/x-pkcs7-signature",
+       .get_context = create_pkcs7_context,
+    },
+};
+
+/* for the specified protocol return the context pointer (initializing
+ * if needed) */
+GMimeCryptoContext *
+_notmuch_crypto_get_gmime_context (_notmuch_crypto_t *crypto, const char *protocol)
+{
+    GMimeCryptoContext *cryptoctx = NULL;
+    size_t i;
+
+    if (! protocol) {
+       fprintf (stderr, "Cryptographic protocol is empty.\n");
+       return cryptoctx;
+    }
+
+    /* As per RFC 1847 section 2.1: "the [protocol] value token is
+     * comprised of the type and sub-type tokens of the Content-Type".
+     * As per RFC 1521 section 2: "Content-Type values, subtypes, and
+     * parameter names as defined in this document are
+     * case-insensitive."  Thus, we use strcasecmp for the protocol.
+     */
+    for (i = 0; i < ARRAY_SIZE (protocols); i++) {
+       if (strcasecmp (protocol, protocols[i].protocol) == 0)
+           return protocols[i].get_context (crypto);
+    }
+
+    fprintf (stderr, "Unknown or unsupported cryptographic protocol %s.\n",
+            protocol);
+
+    return NULL;
+}
+
+void
+_notmuch_crypto_cleanup (_notmuch_crypto_t *crypto)
+{
+    if (crypto->gpgctx) {
+       g_object_unref (crypto->gpgctx);
+       crypto->gpgctx = NULL;
+    }
+
+    if (crypto->pkcs7ctx) {
+       g_object_unref (crypto->pkcs7ctx);
+       crypto->pkcs7ctx = NULL;
+    }
+}
+#else
+void _notmuch_crypto_cleanup (unused(_notmuch_crypto_t *crypto))
+{
+}
+#endif