prop224: Add module that performs the HS ntor handshake.

and also does the key expansion.

1 files changed, 77 insertions, 0 deletions

diff --git a/src/or/hs_ntor.h b/src/or/hs_ntor.h
new file mode 100644
index 0000000000..cd75f46a4c
--- /dev/null
+++ b/src/or/hs_ntor.h
@@ -0,0 +1,77 @@
+/* Copyright (c) 2017, The Tor Project, Inc. */
+/* See LICENSE for licensing information */
+
+#ifndef TOR_HS_NTOR_H
+#define TOR_HS_NTOR_H
+
+#include "or.h"
+
+/* Key material needed to encode/decode INTRODUCE1 cells */
+typedef struct {
+  /* Key used for encryption of encrypted INTRODUCE1 blob */
+  uint8_t enc_key[CIPHER256_KEY_LEN];
+  /* MAC key used to protect encrypted INTRODUCE1 blob */
+  uint8_t mac_key[DIGEST256_LEN];
+} hs_ntor_intro_cell_keys_t;
+
+/* Key material needed to encode/decode RENDEZVOUS1 cells */
+typedef struct {
+  /* This is the MAC of the HANDSHAKE_INFO field */
+  uint8_t rend_cell_auth_mac[DIGEST256_LEN];
+  /* This is the key seed used to derive further rendezvous crypto keys as
+   * detailed in section 4.2.1 of rend-spec-ng.txt. */
+  uint8_t ntor_key_seed[DIGEST256_LEN];
+} hs_ntor_rend_cell_keys_t;
+
+/* Key material resulting from key expansion as detailed in section "4.2.1. Key
+ * expansion" of rend-spec-ng.txt. */
+typedef struct {
+  /* Per-circuit key material used in ESTABLISH_INTRO cell */
+  uint8_t KH[DIGEST256_LEN];
+  /* Authentication key for outgoing RELAY cells */
+  uint8_t Df[DIGEST256_LEN];
+  /* Authentication key for incoming RELAY cells */
+  uint8_t Db[DIGEST256_LEN];
+  /* Encryption key for outgoing RELAY cells */
+  uint8_t Kf[CIPHER256_KEY_LEN];
+  /* Decryption key for incoming RELAY cells */
+  uint8_t Kb[CIPHER256_KEY_LEN];
+} hs_ntor_rend_circuit_keys_t;
+
+int hs_ntor_client_get_introduce1_keys(
+                      const ed25519_public_key_t *intro_auth_pubkey,
+                      const curve25519_public_key_t *intro_enc_pubkey,
+                      const curve25519_keypair_t *client_ephemeral_enc_keypair,
+                      const uint8_t *subcredential,
+                      hs_ntor_intro_cell_keys_t *hs_ntor_intro_cell_keys_out);
+
+int hs_ntor_client_get_rendezvous1_keys(
+                  const ed25519_public_key_t *intro_auth_pubkey,
+                  const curve25519_keypair_t *client_ephemeral_enc_keypair,
+                  const curve25519_public_key_t *intro_enc_pubkey,
+                  const curve25519_public_key_t *service_ephemeral_rend_pubkey,
+                  hs_ntor_rend_cell_keys_t *hs_ntor_rend_cell_keys_out);
+
+int hs_ntor_service_get_introduce1_keys(
+                  const ed25519_public_key_t *intro_auth_pubkey,
+                  const curve25519_keypair_t *intro_enc_keypair,
+                  const curve25519_public_key_t *client_ephemeral_enc_pubkey,
+                  const uint8_t *subcredential,
+                  hs_ntor_intro_cell_keys_t *hs_ntor_intro_cell_keys_out);
+
+int hs_ntor_service_get_rendezvous1_keys(
+                  const ed25519_public_key_t *intro_auth_pubkey,
+                  const curve25519_keypair_t *intro_enc_keypair,
+                  const curve25519_keypair_t *service_ephemeral_rend_keypair,
+                  const curve25519_public_key_t *client_ephemeral_enc_pubkey,
+                  hs_ntor_rend_cell_keys_t *hs_ntor_rend_cell_keys_out);
+
+hs_ntor_rend_circuit_keys_t *hs_ntor_circuit_key_expansion(
+                       const hs_ntor_rend_cell_keys_t *hs_ntor_rend_cell_keys);
+
+int hs_ntor_client_rendezvous2_mac_is_good(
+                        const hs_ntor_rend_cell_keys_t *hs_ntor_rend_cell_keys,
+                        const uint8_t *rcvd_mac);
+
+#endif
+