[PATCH 6/8] cli: crypto: S/MIME verification support

[David Bremner <david@tethera.net>]

From: Jani Nikula <jani@nikula.org>

notmuch-show --verify will now also process S/MIME multiparts if
encountered. Requires gmime-2.6 and gpgsm.

Based on work by Jameson Graef Rollins <jrollins@finestructure.net>.
---
 crypto.c           | 50 ++++++++++++++++++++++++++++++++++++++++++++++++++
 notmuch-client.h   |  7 +++++--
 test/T355-smime.sh |  1 -
 3 files changed, 55 insertions(+), 3 deletions(-)

diff --git a/crypto.c b/crypto.c
index 11c167e..ce683d2 100644
--- a/crypto.c
+++ b/crypto.c
@@ -43,6 +43,51 @@ create_gpg_context (notmuch_crypto_t *crypto)
     return gpgctx;
 }
 
+/* Create a PKCS7 context (GMime 2.6) */
+static notmuch_crypto_context_t *
+create_pkcs7_context (notmuch_crypto_t *crypto)
+{
+    notmuch_crypto_context_t *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;
+    notmuch_crypto_context_t *(*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) */
 notmuch_crypto_context_t *
@@ -81,5 +126,10 @@ notmuch_crypto_cleanup (notmuch_crypto_t *crypto)
 	crypto->gpgctx = NULL;
     }
 
+    if (crypto->pkcs7ctx) {
+	g_object_unref (crypto->pkcs7ctx);
+	crypto->pkcs7ctx = NULL;
+    }
+
     return 0;
 }
diff --git a/notmuch-client.h b/notmuch-client.h
index 1f82656..774b620 100644
--- a/notmuch-client.h
+++ b/notmuch-client.h
@@ -31,6 +31,8 @@
 #include <gmime/gmime.h>
 
 typedef GMimeCryptoContext notmuch_crypto_context_t;
+/* This is automatically included only since gmime 2.6.10 */
+#include <gmime/gmime-pkcs7-context.h>
 
 #include "notmuch.h"
 
@@ -69,6 +71,7 @@ typedef struct notmuch_show_format {
 
 typedef struct notmuch_crypto {
     notmuch_crypto_context_t* gpgctx;
+    notmuch_crypto_context_t* pkcs7ctx;
     notmuch_bool_t verify;
     notmuch_bool_t decrypt;
     const char *gpgpath;
@@ -406,8 +409,8 @@ struct mime_node {
 /* Construct a new MIME node pointing to the root message part of
  * message. If crypto->verify is true, signed child parts will be
  * verified. If crypto->decrypt is true, encrypted child parts will be
- * decrypted.  If crypto->gpgctx is NULL, it will be lazily
- * initialized.
+ * decrypted.  If the crypto contexts (crypto->gpgctx or
+ * crypto->pkcs7) are NULL, they will be lazily initialized.
  *
  * Return value:
  *
diff --git a/test/T355-smime.sh b/test/T355-smime.sh
index b3cc76e..caedf5e 100755
--- a/test/T355-smime.sh
+++ b/test/T355-smime.sh
@@ -56,7 +56,6 @@ EOF
 test_expect_equal_file OUTPUT EXPECTED
 
 test_begin_subtest "signature verification (notmuch CLI)"
-test_subtest_known_broken
 output=$(notmuch show --format=json --verify subject:"test signed message 001" \
     | notmuch_json_show_sanitize \
     | sed -e 's|"created": [1234567890]*|"created": 946728000|' \
-- 
2.5.0