[PATCH v4 04/16] Provide _notmuch_crypto_{set,get}_gpg_path

[Daniel Kahn Gillmor <dkg@fifthhorseman.net>]

Use functions to access the gpg_path for a _notmuch_crypto_t object.
This lets us return sensible defaults based on the state of the user's
machine.

If the passed-in _notmuch_crypto_t is NULL, then just return the
system's default choice of gpg.
---
 notmuch-reply.c | 13 ++++++++++---
 notmuch-show.c  | 12 ++++++++++--
 util/crypto.c   | 50 +++++++++++++++++++++++++++++++++++++++++++++++---
 util/crypto.h   |  8 +++++++-
 4 files changed, 74 insertions(+), 9 deletions(-)

diff --git a/notmuch-reply.c b/notmuch-reply.c
index 42aef47..d0b4a0d 100644
--- a/notmuch-reply.c
+++ b/notmuch-reply.c
@@ -790,13 +790,15 @@ notmuch_reply_command (notmuch_config_t *config, int argc, char *argv[])
 	.crypto = {
 	    .verify = FALSE,
 	    .decrypt = FALSE,
-	    .gpgpath = NULL
+	    .gpg_path = NULL
 	}
     };
     int format = FORMAT_DEFAULT;
     int reply_all = TRUE;
     struct sprinter *sp = NULL;
-
+    notmuch_status_t status;
+    const char *gpg_path = NULL;
+    
     notmuch_opt_desc_t options[] = {
 	{ NOTMUCH_OPT_KEYWORD, &format, "format", 'f',
 	  (notmuch_keyword_t []){ { "default", FORMAT_DEFAULT },
@@ -845,7 +847,12 @@ notmuch_reply_command (notmuch_config_t *config, int argc, char *argv[])
 	return EXIT_FAILURE;
     }
 
-    params.crypto.gpgpath = notmuch_config_get_crypto_gpg_path (config);
+    gpg_path = notmuch_config_get_crypto_gpg_path (config);
+    status = _notmuch_crypto_set_gpg_path (&(params.crypto), gpg_path);
+    if (status != NOTMUCH_STATUS_SUCCESS) {
+	fprintf (stderr, "Error: could not set gpg_path to '%s'.\n", gpg_path);
+	return EXIT_FAILURE;
+    }
 
     if (notmuch_database_open (notmuch_config_get_database_path (config),
 			       NOTMUCH_DATABASE_MODE_READ_ONLY, &notmuch))
diff --git a/notmuch-show.c b/notmuch-show.c
index 8ebf4ff..60411d0 100644
--- a/notmuch-show.c
+++ b/notmuch-show.c
@@ -1006,13 +1006,15 @@ notmuch_show_command (notmuch_config_t *config, int argc, char *argv[])
 	.crypto = {
 	    .verify = FALSE,
 	    .decrypt = FALSE,
-	    .gpgpath = NULL
+	    .gpg_path = NULL
 	},
 	.include_html = FALSE
     };
     int format_sel = NOTMUCH_FORMAT_NOT_SPECIFIED;
     int exclude = EXCLUDE_TRUE;
     int entire_thread = ENTIRE_THREAD_DEFAULT;
+    notmuch_status_t status;
+    const char *gpg_path = NULL;
 
     notmuch_opt_desc_t options[] = {
 	{ NOTMUCH_OPT_KEYWORD, &format_sel, "format", 'f',
@@ -1130,7 +1132,13 @@ notmuch_show_command (notmuch_config_t *config, int argc, char *argv[])
 	return EXIT_FAILURE;
     }
 
-    params.crypto.gpgpath = notmuch_config_get_crypto_gpg_path (config);
+
+    gpg_path = notmuch_config_get_crypto_gpg_path (config);
+    status = _notmuch_crypto_set_gpg_path (&(params.crypto), gpg_path);
+    if (status != NOTMUCH_STATUS_SUCCESS) {
+	fprintf (stderr, "Error: could not set gpg_path to '%s'.\n", gpg_path);
+	return EXIT_FAILURE;
+    }
 
     if (notmuch_database_open (notmuch_config_get_database_path (config),
 			       NOTMUCH_DATABASE_MODE_READ_ONLY, &notmuch))
diff --git a/util/crypto.c b/util/crypto.c
index cce5cbc..9766c2c 100644
--- a/util/crypto.c
+++ b/util/crypto.c
@@ -21,7 +21,9 @@
 
 #include "notmuch.h"
 #include "crypto.h"
+#include "search-path.h"
 #include <string.h>
+#include <talloc.h>
 
 #define ARRAY_SIZE(arr) (sizeof (arr) / sizeof (arr[0]))
 
@@ -38,7 +40,7 @@ get_gpg_context (_notmuch_crypto_t *crypto, GMimeCryptoContext **ctx)
     }
 
     /* TODO: GMimePasswordRequestFunc */
-    crypto->gpgctx = g_mime_gpg_context_new (NULL, crypto->gpgpath ? crypto->gpgpath : "gpg");
+    crypto->gpgctx = g_mime_gpg_context_new (NULL, _notmuch_crypto_get_gpg_path (crypto));
     if (! crypto->gpgctx) {
 	return NOTMUCH_STATUS_FAILED_CRYPTO_CONTEXT_CREATION;
     }
@@ -51,7 +53,7 @@ get_gpg_context (_notmuch_crypto_t *crypto, GMimeCryptoContext **ctx)
 }
 
 /* Create or pass on a PKCS7 context (GMime 2.6) */
-static notmuch_status_t 
+static notmuch_status_t
 get_pkcs7_context (_notmuch_crypto_t *crypto, GMimeCryptoContext **ctx)
 {
     if (ctx == NULL || crypto == NULL)
@@ -76,7 +78,7 @@ get_pkcs7_context (_notmuch_crypto_t *crypto, GMimeCryptoContext **ctx)
 }
 static const struct {
     const char *protocol;
-    notmuch_status_t (*get_context) (_notmuch_crypto_t *crypto, GMimeCryptoContext **ctx);
+    notmuch_status_t (*get_context)(_notmuch_crypto_t *crypto, GMimeCryptoContext **ctx);
 } protocols[] = {
     {
 	.protocol = "application/pgp-signature",
@@ -120,6 +122,45 @@ _notmuch_crypto_get_gmime_ctx_for_protocol (_notmuch_crypto_t *crypto,
     return NOTMUCH_STATUS_UNKNOWN_CRYPTO_PROTOCOL;
 }
 
+const char *
+_notmuch_crypto_get_gpg_path (const _notmuch_crypto_t *crypto)
+{
+    if (crypto && crypto->gpg_path)
+	return crypto->gpg_path;
+
+    if (test_for_executable ("gpg2")) return "gpg2";
+    if (test_for_executable ("gpg")) return "gpg";
+    return NULL;
+}
+
+notmuch_status_t
+_notmuch_crypto_set_gpg_path (_notmuch_crypto_t *crypto, const char *gpg_path)
+{
+    /* return success if this matches what is already configured */
+    if ((! gpg_path && ! crypto->gpg_path) ||
+	(gpg_path && crypto->gpg_path && 0 == strcmp (gpg_path, crypto->gpg_path)))
+	return NOTMUCH_STATUS_SUCCESS;
+
+    if (! gpg_path && ! test_for_executable (gpg_path))
+	return NOTMUCH_STATUS_FILE_ERROR;
+
+    /* clear any existing gpgctx, since things are changing */
+    if (crypto->gpgctx) {
+	g_object_unref (crypto->gpgctx);
+	crypto->gpgctx = NULL;
+    }
+
+    if (crypto->gpg_path) {
+	talloc_free (crypto->gpg_path);
+	crypto->gpg_path = NULL;
+    }
+
+    if (gpg_path)
+	crypto->gpg_path = talloc_strdup (NULL, gpg_path);
+
+    return NOTMUCH_STATUS_SUCCESS;
+}
+
 void
 _notmuch_crypto_cleanup (_notmuch_crypto_t *crypto)
 {
@@ -132,4 +173,7 @@ _notmuch_crypto_cleanup (_notmuch_crypto_t *crypto)
 	g_object_unref (crypto->pkcs7ctx);
 	crypto->pkcs7ctx = NULL;
     }
+
+    talloc_free (crypto->gpg_path);
+    crypto->gpg_path = NULL;
 }
diff --git a/util/crypto.h b/util/crypto.h
index 7cb0a39..70fc8ef 100644
--- a/util/crypto.h
+++ b/util/crypto.h
@@ -11,7 +11,7 @@ typedef struct _notmuch_crypto {
     GMimeCryptoContext* pkcs7ctx;
     notmuch_bool_t verify;
     notmuch_bool_t decrypt;
-    const char *gpgpath;
+    char *gpg_path;
 } _notmuch_crypto_t;
 
 
@@ -20,6 +20,12 @@ _notmuch_crypto_get_gmime_ctx_for_protocol (_notmuch_crypto_t *crypto,
 					    const char *protocol,
 					    GMimeCryptoContext **ctx);
 
+notmuch_status_t
+_notmuch_crypto_set_gpg_path (_notmuch_crypto_t *crypto, const char *gpg_path);
+
+const char *
+_notmuch_crypto_get_gpg_path (const _notmuch_crypto_t *crypto);
+
 void
 _notmuch_crypto_cleanup (_notmuch_crypto_t *crypto);
 
-- 
2.8.1