ffi: New example.

2 files changed, 117 insertions, 1 deletions

diff --git a/ffi/examples/Makefile b/ffi/examples/Makefile
index 5638d5f8..3b7b6794 100644
--- a/ffi/examples/Makefile
+++ b/ffi/examples/Makefile
@@ -1,6 +1,6 @@
 # Makefile for examples written in C.
 
-TARGETS = example keyserver configure reader parser
+TARGETS = example keyserver configure reader parser encrypt-for
 CFLAGS  = -I../include -O0 -g -Wall
 LDFLAGS = -L../../target/debug -lsequoia_ffi
 
diff --git a/ffi/examples/encrypt-for.c b/ffi/examples/encrypt-for.c
new file mode 100644
index 00000000..637585d4
--- /dev/null
+++ b/ffi/examples/encrypt-for.c
@@ -0,0 +1,116 @@
+/* This example demonstrates how to use the low-level interface to
+   encrypt a file.  */
+
+#define _GNU_SOURCE
+#include <error.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <stdio.h>
+#include <sys/mman.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+#include <unistd.h>
+#include <time.h>
+
+#include <sequoia.h>
+
+int
+main (int argc, char **argv)
+{
+  struct stat st;
+  int fd;
+  uint8_t *b;
+  sq_status_t rc;
+  sq_error_t err;
+  sq_context_t ctx;
+  int use_armor = 1;
+  sq_tpk_t tpk;
+  sq_writer_t sink;
+  sq_writer_stack_t writer = NULL;
+  void *cipher = NULL;
+  size_t cipher_bytes = 0;
+
+  if (argc != 2)
+    error (1, 0, "Usage: %s <keyfile> <plain >cipher", argv[0]);
+
+  ctx = sq_context_new ("org.sequoia-pgp.example", &err);
+  if (ctx == NULL)
+    error (1, 0, "Initializing sequoia failed: %s",
+           sq_error_string (err));
+
+  if (stat (argv[1], &st))
+    error (1, errno, "%s", argv[1]);
+
+  fd = open (argv[1], O_RDONLY);
+  if (fd == -1)
+    error (1, errno, "%s", argv[1]);
+
+  b = mmap (NULL, st.st_size, PROT_READ, MAP_SHARED, fd, 0);
+  close (fd);
+  if (b == MAP_FAILED)
+    error (1, errno, "mmap");
+
+  tpk = sq_tpk_from_bytes (ctx, b, st.st_size);
+  if (tpk == NULL)
+    {
+      err = sq_context_last_error (ctx);
+      error (1, 0, "sq_packet_parser_from_bytes: %s", sq_error_string (err));
+    }
+
+  sink = sq_writer_alloc (&cipher, &cipher_bytes);
+
+  if (use_armor)
+    sink = sq_armor_writer_new (sink, SQ_ARMOR_KIND_MESSAGE);
+
+  writer = sq_writer_stack_wrap (sink);
+  writer = sq_encryptor_new (ctx,
+			     writer,
+			     NULL, 0, /* no passwords */
+			     &tpk, 1,
+			     SQ_ENCRYPTION_MODE_FOR_TRANSPORT);
+  if (writer == NULL)
+    {
+      err = sq_context_last_error (ctx);
+      error (1, 0, "sq_encryptor_new: %s", sq_error_string (err));
+    }
+
+  writer = sq_literal_writer_new (ctx, writer);
+  if (writer == NULL)
+    {
+      err = sq_context_last_error (ctx);
+      error (1, 0, "sq_literal_writer_new: %s", sq_error_string (err));
+    }
+
+  size_t nread;
+  uint8_t buf[4096];
+  while ((nread = fread (buf, 1, sizeof buf, stdin)))
+    {
+      uint8_t *b = buf;
+      while (nread)
+	{
+	  ssize_t written;
+	  written = sq_writer_stack_write (ctx, writer, b, nread);
+	  if (written < 0)
+	    {
+	      err = sq_context_last_error (ctx);
+	      error (1, 0, "sq_writer_stack_write: %s", sq_error_string (err));
+	    }
+	  b += written;
+	  nread -= written;
+	}
+    }
+
+  rc = sq_writer_stack_finalize (ctx, writer);
+  writer = NULL;
+  if (rc)
+    {
+      err = sq_context_last_error (ctx);
+      error (1, 0, "sq_writer_stack_write: %s", sq_error_string (err));
+    }
+
+  fwrite (cipher, 1, cipher_bytes, stdout);
+
+  sq_context_free (ctx);
+  munmap (b, st.st_size);
+  return 0;
+}