1 files changed, 153 insertions, 0 deletions
diff --git a/lib/ngtcp2_ppe.h b/lib/ngtcp2_ppe.h
new file mode 100644
index 0000000..bf220df
--- /dev/null
+++ b/lib/ngtcp2_ppe.h
@@ -0,0 +1,153 @@
+/*
+ * ngtcp2
+ *
+ * Copyright (c) 2017 ngtcp2 contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining
+ * a copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sublicense, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be
+ * included in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+ * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+ * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+ * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ */
+#ifndef NGTCP2_PPE_H
+#define NGTCP2_PPE_H
+
+#ifdef HAVE_CONFIG_H
+#  include <config.h>
+#endif /* HAVE_CONFIG_H */
+
+#include <ngtcp2/ngtcp2.h>
+
+#include "ngtcp2_pkt.h"
+#include "ngtcp2_buf.h"
+#include "ngtcp2_crypto.h"
+
+/*
+ * ngtcp2_ppe is the Protected Packet Encoder.
+ */
+typedef struct ngtcp2_ppe {
+  ngtcp2_buf buf;
+  ngtcp2_crypto_cc *cc;
+  /* hdlen is the number of bytes for packet header written in buf. */
+  size_t hdlen;
+  /* len_offset is the offset to Length field. */
+  size_t len_offset;
+  /* pkt_num_offset is the offset to packet number field. */
+  size_t pkt_num_offset;
+  /* pkt_numlen is the number of bytes used to encode a packet
+     number */
+  size_t pkt_numlen;
+  /* sample_offset is the offset to sample for packet number
+     encryption. */
+  size_t sample_offset;
+  /* pkt_num is the packet number written in buf. */
+  int64_t pkt_num;
+  /* nonce is the buffer to store nonce.  It should be equal or longer
+     than then length of IV. */
+  uint8_t nonce[32];
+} ngtcp2_ppe;
+
+/*
+ * ngtcp2_ppe_init initializes |ppe| with the given buffer.
+ */
+void ngtcp2_ppe_init(ngtcp2_ppe *ppe, uint8_t *out, size_t outlen,
+                     ngtcp2_crypto_cc *cc);
+
+/*
+ * ngtcp2_ppe_encode_hd encodes |hd|.
+ *
+ * This function returns 0 if it succeeds, or one of the following
+ * negative error codes:
+ *
+ * NGTCP2_ERR_NOBUF
+ *     The buffer is too small.
+ */
+int ngtcp2_ppe_encode_hd(ngtcp2_ppe *ppe, const ngtcp2_pkt_hd *hd);
+
+/*
+ * ngtcp2_ppe_encode_frame encodes |fr|.
+ *
+ * This function returns 0 if it succeeds, or one of the following
+ * negative error codes:
+ *
+ * NGTCP2_ERR_NOBUF
+ *     The buffer is too small.
+ */
+int ngtcp2_ppe_encode_frame(ngtcp2_ppe *ppe, ngtcp2_frame *fr);
+
+/*
+ * ngtcp2_ppe_final encrypts QUIC packet payload.  If |**ppkt| is not
+ * NULL, the pointer to the packet is assigned to it.
+ *
+ * This function returns the length of QUIC packet, including header,
+ * and payload if it succeeds, or one of the following negative error
+ * codes:
+ *
+ * NGTCP2_ERR_CALLBACK_FAILURE
+ *     User-defined callback function failed.
+ */
+ngtcp2_ssize ngtcp2_ppe_final(ngtcp2_ppe *ppe, const uint8_t **ppkt);
+
+/*
+ * ngtcp2_ppe_left returns the number of bytes left to write
+ * additional frames.  This does not count AEAD overhead.
+ */
+size_t ngtcp2_ppe_left(ngtcp2_ppe *ppe);
+
+/*
+ * ngtcp2_ppe_pktlen returns the provisional packet length.  It
+ * includes AEAD overhead.
+ */
+size_t ngtcp2_ppe_pktlen(ngtcp2_ppe *ppe);
+
+/**
+ * @function
+ *
+ * `ngtcp2_ppe_padding` encodes PADDING frames to the end of the
+ * buffer.  This function returns the number of bytes padded.
+ */
+size_t ngtcp2_ppe_padding(ngtcp2_ppe *ppe);
+
+/*
+ * ngtcp2_ppe_padding_hp_sample adds PADDING frame if the current
+ * payload does not have enough space for header protection sample.
+ * This function should be called just before calling
+ * ngtcp2_ppe_final().
+ *
+ * This function returns the number of bytes added as padding.
+ */
+size_t ngtcp2_ppe_padding_hp_sample(ngtcp2_ppe *ppe);
+
+/*
+ * ngtcp2_ppe_padding_size adds PADDING frame so that the size of QUIC
+ * packet is at least |n| bytes long.  If it is unable to add PADDING
+ * in that way, this function still adds PADDING frame as much as
+ * possible.  This function should be called just before calling
+ * ngtcp2_ppe_final().  For Short packet, this function should be
+ * called instead of ngtcp2_ppe_padding_hp_sample.
+ *
+ * This function returns the number of bytes added as padding.
+ */
+size_t ngtcp2_ppe_padding_size(ngtcp2_ppe *ppe, size_t n);
+
+/*
+ * ngtcp2_ppe_ensure_hp_sample returns nonzero if the buffer has
+ * enough space for header protection sample.  This should be called
+ * right after packet header is written.
+ */
+int ngtcp2_ppe_ensure_hp_sample(ngtcp2_ppe *ppe);
+
+#endif /* NGTCP2_PPE_H */