1 files changed, 88 insertions, 0 deletions
diff --git a/src/utilities.h b/src/utilities.h
new file mode 100644
index 0000000..b5b91f9
--- /dev/null
+++ b/src/utilities.h
@@ -0,0 +1,88 @@
+#ifndef H_UTILITIES_INCLUDED
+#define H_UTILITIES_INCLUDED
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif /* HAVE_CONFIG_H */
+
+#include <libguile.h>
+#include <assert.h>
+#include <string.h>
+#include <stdlib.h>
+#include <nettle/base64.h>
+#include <nettle/ecc.h>
+#include <nettle/ecdsa.h>
+#include <nettle/rsa.h>
+#include <nettle/ecc-curve.h>
+#include <nettle/yarrow.h>
+#include <gettext.h>
+#include <stdio.h>
+#include <unistd.h>
+
+/* Return a base64 encoding of some raw data. */
+static SCM wrap_bytevector (size_t length, uint8_t * data);
+
+/* Decode a base64 of binary data. */
+static uint8_t *get_as_bytevector (SCM data, size_t *size, int throw_if_fail);
+
+static inline SCM
+wrap_bytevector (size_t length, uint8_t * data)
+{
+  char *head;
+  char tail[BASE64_ENCODE_FINAL_LENGTH];
+  size_t head_size, tail_size;
+  char *full;
+  struct base64_encode_ctx encoder;
+  SCM ret;
+  base64url_encode_init (&encoder);
+  scm_dynwind_begin (0);
+  head = scm_malloc (BASE64_ENCODE_LENGTH (length));
+  scm_dynwind_free (head);
+  head_size = base64_encode_update (&encoder, head, length, data);
+  tail_size = base64_encode_final (&encoder, tail);
+  while (tail_size != 0 && tail[tail_size - 1] == '=')
+    {
+      tail_size--;
+    }
+  full = scm_malloc (head_size + tail_size);
+  memcpy (full, head, head_size);
+  memcpy (full + head_size, tail, tail_size);
+  ret = scm_from_utf8_stringn (full, head_size + tail_size);
+  scm_dynwind_end ();
+  return ret;
+}
+
+static inline uint8_t *
+get_as_bytevector (SCM data, size_t *size, int throw_if_fail)
+{
+  uint8_t *ret = NULL;
+  size_t data_length;
+  char *data_str = NULL;
+  struct base64_decode_ctx decoder;
+  int ok = 1;
+  if (!scm_is_bytevector (data) && !throw_if_fail)
+    {
+      return NULL;
+    }
+  base64url_decode_init (&decoder);
+  scm_dynwind_begin (0);
+  data_str = scm_to_utf8_stringn (data, &data_length);
+  scm_dynwind_free (data_str);
+  ret = scm_malloc (BASE64_DECODE_LENGTH (data_length));
+  /* Not protected! Nothing will throw until scm_dynwind_end. */
+  ok = base64_decode_update (&decoder, size, ret, data_length, data_str);
+  scm_dynwind_end ();
+  if (!ok)
+    {
+      ret = NULL;
+      if (throw_if_fail)
+	{
+	  SCM base64_decoding_error =
+	    scm_from_utf8_symbol ("base64-decoding-error");
+	  scm_throw (base64_decoding_error, scm_list_1 (data));
+	}
+    }
+  return ret;
+}
+
+#endif /* not H_UTILITIES_INCLUDED */