added pcpstream, which wraps buffers or file i/o, so crypto code doesn't have to know if it works with a file or a buffer. makes the api much more flexible

libpcp/pcpstream.c

@@ -0,0 +1,125 @@
+/*
+    This file is part of Pretty Curved Privacy (pcp1).
+
+    Copyright (C) 2013-2014 T.v.Dein.
+
+    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, either version 3 of the License, or
+    (at your option) any later version.
+
+    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 <http://www.gnu.org/licenses/>.
+
+    You can contact me by mail: <tom AT vondein DOT org>.
+*/
+
+#include "pcpstream.h"
+
+Pcpstream *ps_init(void) {
+  Pcpstream *stream = ucmalloc(sizeof(Pcpstream));
+  stream->b = NULL;
+  stream->fd = NULL;
+  stream->is_buffer = 0;
+  stream->eof = 0;
+  stream->err = 0;
+  return stream;
+}
+
+Pcpstream *ps_new_file(FILE *backendfd) {
+  Pcpstream *stream = ps_init();
+  stream->fd = backendfd;
+  return stream;
+}
+
+Pcpstream *ps_new_inbuffer(Buffer *b) {
+  Pcpstream *stream = ps_init();
+  stream->b = b;
+  stream->is_buffer = 1;
+  return stream;
+}
+
+Pcpstream *ps_new_outbuffer() {
+  Pcpstream *stream = ps_init();
+  stream->b = buffer_new(32, "Pcpstream");
+  stream->is_buffer = 1;
+  return stream;
+}
+
+size_t ps_read(Pcpstream *stream, void *buf, size_t readbytes) {
+  size_t gotbytes = 0;
+
+  if(stream->is_buffer) {
+    gotbytes = buffer_get_chunk(stream->b, buf, readbytes);
+    if(gotbytes == 0) {
+      /* this should not happen with buffers */
+      stream->eof = 1;
+      stream->err = 1;
+    }
+  }
+  else {
+    gotbytes = fread(buf, 1, readbytes, stream->fd);
+    if(gotbytes == 0) {
+      if(feof(stream->fd) != 0)
+	stream->eof = 1;
+      if(ferror(stream->fd) != 0)
+	stream->err = 1;
+    }
+  }
+
+  return gotbytes;
+}
+
+size_t ps_write(Pcpstream *stream, void *buf, size_t writebytes) {
+  size_t donebytes = 0;
+
+  if(stream->is_buffer) {
+    buffer_add(stream->b, buf, writebytes);
+    donebytes = writebytes;
+  }
+  else {
+    donebytes = fwrite(buf, 1, writebytes, stream->fd);
+    if(ferror(stream->fd) != 0 || donebytes < writebytes)
+      stream->err = 1;
+  }
+
+  return writebytes;
+}
+
+void ps_close(Pcpstream *stream) {
+  if(stream->is_buffer) {
+    buffer_clear(stream->b);
+    free(stream);
+  }
+  else {
+    /* only close files, not terminal devices */
+    if(fileno(stream->fd) > 2)
+      fclose(stream->fd);
+    free(stream);
+  }
+}
+
+int ps_end(Pcpstream *stream) {
+  return stream->eof;
+}
+
+int ps_err(Pcpstream *stream) {
+  return stream->err;
+}
+
+size_t ps_tell(Pcpstream *stream) {
+  if(stream->is_buffer) {
+    if(stream->b->end > stream->b->offset)
+      return stream->b->end; /* write buffer */
+    else
+      return stream->b->offset; /* read buffer */
+  }
+  else {
+    return ftell(stream->fd);
+  }
+}