Add a helper for reading OpenPGP packets from a file

[onak.git] / key-store.c

diff --git a/key-store.c b/key-store.c
new file mode 100644 (file)
index 0000000..e7b0d3e
--- /dev/null
+++ b/key-store.c
@@ -0,0 +1,76 @@
+/*
+ * key-store.c - High level routines to load + save OpenPGP packets/keys
+ *
+ * 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; version 2 of the License.
+ *
+ * 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/>.
+ */
+
+#include <errno.h>
+#include <fcntl.h>
+#include <unistd.h>
+
+#include "build-config.h"
+
+#include "armor.h"
+#include "charfuncs.h"
+#include "key-store.h"
+#include "keystructs.h"
+#include "onak.h"
+#include "parsekey.h"
+
+/**
+ *     onak_read_openpgp_file - Reads a set of OpenPGP packets from a file
+ *     @file: The file to open and read
+ *     @packets: The returned packet list
+ *
+ *     This function opens the supplied file and tries to parse it as a set
+ *     of OpenPGP packets. It will attempt to autodetect if the file is ASCII
+ *     armored, or binary packets, and adapt accordingly. The packets read are
+ *     returned in the packets parameter. It is the callers responsbility to
+ *     free the packet memory when it is no longe required, e.g. using
+ *     free_packet_list.
+ *
+ *     Returns a status code indicating any error.
+ */
+onak_status_t onak_read_openpgp_file(const char *file,
+               struct openpgp_packet_list **packets)
+{
+       onak_status_t res;
+       int fd, ret;
+       char c;
+
+       fd = open(file, O_RDONLY);
+       if (fd < 0) {
+               return (errno == ENOENT) ? ONAK_E_NOT_FOUND : ONAK_E_IO_ERROR;
+       }
+
+       /* Peek at the first byte in the file */
+       ret = read(fd, &c, 1);
+       if (ret != 1) {
+               return ONAK_E_IO_ERROR;
+       }
+       lseek(fd, 0, SEEK_SET);
+
+       /*
+        * A binary OpenPGP packet will have the top bit set on its first byte,
+        * so we use that to determine if we should try to process the stream
+        * as binary or ASCII armored data.
+        */
+       if (c & 0x80) {
+               res = read_openpgp_stream(file_fetchchar, &fd,
+                        packets, 0);
+       } else {
+               res = dearmor_openpgp_stream(file_fetchchar, &fd, packets);
+       }
+
+       return res;
+}