1 files changed, 170 insertions, 169 deletions

diff --git a/src/openvpn/tls_crypt.c b/src/openvpn/tls_crypt.c
index d40532e..c227b09 100644
--- a/src/openvpn/tls_crypt.c
+++ b/src/openvpn/tls_crypt.c
@@ -5,7 +5,7 @@
  *             packet encryption, packet authentication, and
  *             packet compression.
  *
- *  Copyright (C) 2016 Fox Crypto B.V. <openvpn@fox-it.com>
+ *  Copyright (C) 2016-2017 Fox Crypto B.V. <openvpn@fox-it.com>
  *
  *  This program is free software; you can redistribute it and/or modify
  *  it under the terms of the GNU General Public License version 2
@@ -36,219 +36,220 @@
 
 #include "tls_crypt.h"
 
-int tls_crypt_buf_overhead(void)
+int
+tls_crypt_buf_overhead(void)
 {
-  return packet_id_size (true) + TLS_CRYPT_TAG_SIZE + TLS_CRYPT_BLOCK_SIZE;
+    return packet_id_size(true) + TLS_CRYPT_TAG_SIZE + TLS_CRYPT_BLOCK_SIZE;
 }
 
 void
-tls_crypt_init_key (struct key_ctx_bi *key, const char *key_file,
-    const char *key_inline, bool tls_server) {
-  const int key_direction = tls_server ?
-      KEY_DIRECTION_NORMAL : KEY_DIRECTION_INVERSE;
-
-  struct key_type kt;
-  kt.cipher = cipher_kt_get ("AES-256-CTR");
-  kt.cipher_length = cipher_kt_key_size (kt.cipher);
-  kt.digest = md_kt_get ("SHA256");
-  kt.hmac_length = md_kt_size (kt.digest);
-
-  if (!kt.cipher)
+tls_crypt_init_key(struct key_ctx_bi *key, const char *key_file,
+                   const char *key_inline, bool tls_server) {
+    const int key_direction = tls_server ?
+                              KEY_DIRECTION_NORMAL : KEY_DIRECTION_INVERSE;
+
+    struct key_type kt;
+    kt.cipher = cipher_kt_get("AES-256-CTR");
+    kt.cipher_length = cipher_kt_key_size(kt.cipher);
+    kt.digest = md_kt_get("SHA256");
+    kt.hmac_length = md_kt_size(kt.digest);
+
+    if (!kt.cipher)
     {
-      msg (M_FATAL, "ERROR: --tls-crypt requires AES-256-CTR support.");
+        msg(M_FATAL, "ERROR: --tls-crypt requires AES-256-CTR support.");
     }
-  if (!kt.digest)
+    if (!kt.digest)
     {
-      msg (M_FATAL, "ERROR: --tls-crypt requires HMAC-SHA-256 support.");
+        msg(M_FATAL, "ERROR: --tls-crypt requires HMAC-SHA-256 support.");
     }
 
-  crypto_read_openvpn_key (&kt, key, key_file, key_inline, key_direction,
-			   "Control Channel Encryption", "tls-crypt");
+    crypto_read_openvpn_key(&kt, key, key_file, key_inline, key_direction,
+                            "Control Channel Encryption", "tls-crypt");
 }
 
 void
 tls_crypt_adjust_frame_parameters(struct frame *frame)
 {
-  frame_add_to_extra_frame (frame, tls_crypt_buf_overhead());
+    frame_add_to_extra_frame(frame, tls_crypt_buf_overhead());
 
-  msg(D_MTU_DEBUG, "%s: Adjusting frame parameters for tls-crypt by %i bytes",
-      __func__, tls_crypt_buf_overhead());
+    msg(D_MTU_DEBUG, "%s: Adjusting frame parameters for tls-crypt by %i bytes",
+        __func__, tls_crypt_buf_overhead());
 }
 
 
 bool
-tls_crypt_wrap (const struct buffer *src, struct buffer *dst,
-	 struct crypto_options *opt) {
-  const struct key_ctx *ctx = &opt->key_ctx_bi.encrypt;
-  struct gc_arena gc;
-
-  /* IV, packet-ID and implicit IV required for this mode. */
-  ASSERT (ctx->cipher);
-  ASSERT (ctx->hmac);
-  ASSERT (packet_id_initialized(&opt->packet_id));
-  ASSERT (hmac_ctx_size(ctx->hmac) == 256/8);
-
-  gc_init (&gc);
-
-  dmsg (D_PACKET_CONTENT, "TLS-CRYPT WRAP FROM: %s",
-      format_hex (BPTR (src), BLEN (src), 80, &gc));
-
-  /* Get packet ID */
-  {
-    struct packet_id_net pin;
-    packet_id_alloc_outgoing (&opt->packet_id.send, &pin, true);
-    packet_id_write (&pin, dst, true, false);
-  }
-
-  dmsg (D_PACKET_CONTENT, "TLS-CRYPT WRAP AD: %s",
-      format_hex (BPTR (dst), BLEN (dst), 0, &gc));
-
-  /* Buffer overflow check */
-  if (!buf_safe (dst, BLEN (src) + TLS_CRYPT_BLOCK_SIZE + TLS_CRYPT_TAG_SIZE))
+tls_crypt_wrap(const struct buffer *src, struct buffer *dst,
+               struct crypto_options *opt) {
+    const struct key_ctx *ctx = &opt->key_ctx_bi.encrypt;
+    struct gc_arena gc;
+
+    /* IV, packet-ID and implicit IV required for this mode. */
+    ASSERT(ctx->cipher);
+    ASSERT(ctx->hmac);
+    ASSERT(packet_id_initialized(&opt->packet_id));
+    ASSERT(hmac_ctx_size(ctx->hmac) == 256/8);
+
+    gc_init(&gc);
+
+    dmsg(D_PACKET_CONTENT, "TLS-CRYPT WRAP FROM: %s",
+         format_hex(BPTR(src), BLEN(src), 80, &gc));
+
+    /* Get packet ID */
     {
-      msg (D_CRYPT_ERRORS, "TLS-CRYPT WRAP: buffer size error, "
-	  "sc=%d so=%d sl=%d dc=%d do=%d dl=%d", src->capacity, src->offset,
-	  src->len, dst->capacity, dst->offset, dst->len);
-      goto err;
+        struct packet_id_net pin;
+        packet_id_alloc_outgoing(&opt->packet_id.send, &pin, true);
+        packet_id_write(&pin, dst, true, false);
     }
 
-  /* Calculate auth tag and synthetic IV */
-  {
-    uint8_t *tag = NULL;
-    hmac_ctx_reset (ctx->hmac);
-    hmac_ctx_update (ctx->hmac, BPTR (dst), BLEN (dst));
-    hmac_ctx_update (ctx->hmac, BPTR (src), BLEN (src));
+    dmsg(D_PACKET_CONTENT, "TLS-CRYPT WRAP AD: %s",
+         format_hex(BPTR(dst), BLEN(dst), 0, &gc));
+
+    /* Buffer overflow check */
+    if (!buf_safe(dst, BLEN(src) + TLS_CRYPT_BLOCK_SIZE + TLS_CRYPT_TAG_SIZE))
+    {
+        msg(D_CRYPT_ERRORS, "TLS-CRYPT WRAP: buffer size error, "
+            "sc=%d so=%d sl=%d dc=%d do=%d dl=%d", src->capacity, src->offset,
+            src->len, dst->capacity, dst->offset, dst->len);
+        goto err;
+    }
+
+    /* Calculate auth tag and synthetic IV */
+    {
+        uint8_t *tag = NULL;
+        hmac_ctx_reset(ctx->hmac);
+        hmac_ctx_update(ctx->hmac, BPTR(dst), BLEN(dst));
+        hmac_ctx_update(ctx->hmac, BPTR(src), BLEN(src));
 
-    ASSERT (tag = buf_write_alloc (dst, TLS_CRYPT_TAG_SIZE));
-    hmac_ctx_final (ctx->hmac, tag);
+        ASSERT(tag = buf_write_alloc(dst, TLS_CRYPT_TAG_SIZE));
+        hmac_ctx_final(ctx->hmac, tag);
 
-    dmsg (D_PACKET_CONTENT, "TLS-CRYPT WRAP TAG: %s",
-        format_hex (tag, TLS_CRYPT_TAG_SIZE, 0, &gc));
+        dmsg(D_PACKET_CONTENT, "TLS-CRYPT WRAP TAG: %s",
+             format_hex(tag, TLS_CRYPT_TAG_SIZE, 0, &gc));
 
-    /* Use the 128 most significant bits of the tag as IV */
-    ASSERT (cipher_ctx_reset (ctx->cipher, tag));
-  }
+        /* Use the 128 most significant bits of the tag as IV */
+        ASSERT(cipher_ctx_reset(ctx->cipher, tag));
+    }
 
-  /* Encrypt src */
-  {
-    int outlen = 0;
-    ASSERT (cipher_ctx_update (ctx->cipher, BEND (dst), &outlen,
-	BPTR (src), BLEN(src)));
-    ASSERT (buf_inc_len (dst, outlen));
-    ASSERT (cipher_ctx_final (ctx->cipher, BPTR (dst), &outlen));
-    ASSERT (buf_inc_len (dst, outlen));
-  }
+    /* Encrypt src */
+    {
+        int outlen = 0;
+        ASSERT(cipher_ctx_update(ctx->cipher, BEND(dst), &outlen,
+                                 BPTR(src), BLEN(src)));
+        ASSERT(buf_inc_len(dst, outlen));
+        ASSERT(cipher_ctx_final(ctx->cipher, BPTR(dst), &outlen));
+        ASSERT(buf_inc_len(dst, outlen));
+    }
 
-  dmsg (D_PACKET_CONTENT, "TLS-CRYPT WRAP TO: %s",
-      format_hex (BPTR (dst), BLEN (dst), 80, &gc));
+    dmsg(D_PACKET_CONTENT, "TLS-CRYPT WRAP TO: %s",
+         format_hex(BPTR(dst), BLEN(dst), 80, &gc));
 
-  gc_free (&gc);
-  return true;
+    gc_free(&gc);
+    return true;
 
 err:
-  crypto_clear_error();
-  dst->len = 0;
-  gc_free (&gc);
-  return false;
+    crypto_clear_error();
+    dst->len = 0;
+    gc_free(&gc);
+    return false;
 }
 
 bool
-tls_crypt_unwrap (const struct buffer *src, struct buffer *dst,
-    struct crypto_options *opt)
+tls_crypt_unwrap(const struct buffer *src, struct buffer *dst,
+                 struct crypto_options *opt)
 {
-  static const char error_prefix[] = "tls-crypt unwrap error";
-  const struct key_ctx *ctx = &opt->key_ctx_bi.decrypt;
-  struct gc_arena gc;
+    static const char error_prefix[] = "tls-crypt unwrap error";
+    const struct key_ctx *ctx = &opt->key_ctx_bi.decrypt;
+    struct gc_arena gc;
 
-  gc_init (&gc);
+    gc_init(&gc);
 
-  ASSERT (opt);
-  ASSERT (src->len > 0);
-  ASSERT (ctx->cipher);
-  ASSERT (packet_id_initialized (&opt->packet_id) ||
-      (opt->flags & CO_IGNORE_PACKET_ID));
+    ASSERT(opt);
+    ASSERT(src->len > 0);
+    ASSERT(ctx->cipher);
+    ASSERT(packet_id_initialized(&opt->packet_id)
+           || (opt->flags & CO_IGNORE_PACKET_ID));
 
-  dmsg (D_PACKET_CONTENT, "TLS-CRYPT UNWRAP FROM: %s",
-      format_hex (BPTR (src), BLEN (src), 80, &gc));
+    dmsg(D_PACKET_CONTENT, "TLS-CRYPT UNWRAP FROM: %s",
+         format_hex(BPTR(src), BLEN(src), 80, &gc));
+
+    if (buf_len(src) < TLS_CRYPT_OFF_CT)
+    {
+        CRYPT_ERROR("packet too short");
+    }
+
+    /* Decrypt cipher text */
+    {
+        int outlen = 0;
+
+        /* Buffer overflow check (should never fail) */
+        if (!buf_safe(dst, BLEN(src) - TLS_CRYPT_OFF_CT + TLS_CRYPT_BLOCK_SIZE))
+        {
+            CRYPT_ERROR("potential buffer overflow");
+        }
+
+        if (!cipher_ctx_reset(ctx->cipher, BPTR(src) + TLS_CRYPT_OFF_TAG))
+        {
+            CRYPT_ERROR("cipher reset failed");
+        }
+        if (!cipher_ctx_update(ctx->cipher, BPTR(dst), &outlen,
+                               BPTR(src) + TLS_CRYPT_OFF_CT, BLEN(src) - TLS_CRYPT_OFF_CT))
+        {
+            CRYPT_ERROR("cipher update failed");
+        }
+        ASSERT(buf_inc_len(dst, outlen));
+        if (!cipher_ctx_final(ctx->cipher, BPTR(dst), &outlen))
+        {
+            CRYPT_ERROR("cipher final failed");
+        }
+        ASSERT(buf_inc_len(dst, outlen));
+    }
 
-  if (buf_len (src) < TLS_CRYPT_OFF_CT)
+    /* Check authentication */
     {
-      CRYPT_ERROR ("packet too short");
+        const uint8_t *tag = BPTR(src) + TLS_CRYPT_OFF_TAG;
+        uint8_t tag_check[TLS_CRYPT_TAG_SIZE] = { 0 };
+
+        dmsg(D_PACKET_CONTENT, "TLS-CRYPT UNWRAP AD: %s",
+             format_hex(BPTR(src), TLS_CRYPT_OFF_TAG, 0, &gc));
+        dmsg(D_PACKET_CONTENT, "TLS-CRYPT UNWRAP TO: %s",
+             format_hex(BPTR(dst), BLEN(dst), 80, &gc));
+
+        hmac_ctx_reset(ctx->hmac);
+        hmac_ctx_update(ctx->hmac, BPTR(src), TLS_CRYPT_OFF_TAG);
+        hmac_ctx_update(ctx->hmac, BPTR(dst), BLEN(dst));
+        hmac_ctx_final(ctx->hmac, tag_check);
+
+        if (memcmp_constant_time(tag, tag_check, sizeof(tag_check)))
+        {
+            dmsg(D_CRYPTO_DEBUG, "tag      : %s",
+                 format_hex(tag, sizeof(tag_check), 0, &gc));
+            dmsg(D_CRYPTO_DEBUG, "tag_check: %s",
+                 format_hex(tag_check, sizeof(tag_check), 0, &gc));
+            CRYPT_ERROR("packet authentication failed");
+        }
     }
 
-  /* Decrypt cipher text */
-  {
-    int outlen = 0;
-
-    /* Buffer overflow check (should never fail) */
-    if (!buf_safe (dst, BLEN (src) - TLS_CRYPT_OFF_CT + TLS_CRYPT_BLOCK_SIZE))
-      {
-	CRYPT_ERROR ("potential buffer overflow");
-      }
-
-    if (!cipher_ctx_reset (ctx->cipher, BPTR (src) + TLS_CRYPT_OFF_TAG))
-      {
-	CRYPT_ERROR ("cipher reset failed");
-      }
-    if (!cipher_ctx_update (ctx->cipher, BPTR (dst), &outlen,
-	BPTR (src) + TLS_CRYPT_OFF_CT, BLEN (src) - TLS_CRYPT_OFF_CT))
-      {
-	CRYPT_ERROR ("cipher update failed");
-      }
-    ASSERT (buf_inc_len (dst, outlen));
-    if (!cipher_ctx_final (ctx->cipher, BPTR(dst), &outlen))
-      {
-	CRYPT_ERROR ("cipher final failed");
-      }
-    ASSERT (buf_inc_len (dst, outlen));
-  }
-
-  /* Check authentication */
-  {
-    const uint8_t *tag = BPTR (src) + TLS_CRYPT_OFF_TAG;
-    uint8_t tag_check[TLS_CRYPT_TAG_SIZE] = { 0 };
-
-    dmsg (D_PACKET_CONTENT, "TLS-CRYPT UNWRAP AD: %s",
-        format_hex (BPTR (src), TLS_CRYPT_OFF_TAG, 0, &gc));
-    dmsg (D_PACKET_CONTENT, "TLS-CRYPT UNWRAP TO: %s",
-         format_hex (BPTR (dst), BLEN (dst), 80, &gc));
-
-    hmac_ctx_reset (ctx->hmac);
-    hmac_ctx_update (ctx->hmac, BPTR (src), TLS_CRYPT_OFF_TAG);
-    hmac_ctx_update (ctx->hmac, BPTR (dst), BLEN (dst));
-    hmac_ctx_final (ctx->hmac, tag_check);
-
-    if (memcmp_constant_time (tag, tag_check, sizeof(tag_check)))
-      {
-	dmsg (D_CRYPTO_DEBUG, "tag      : %s",
-	    format_hex (tag, sizeof(tag_check), 0, &gc));
-	dmsg (D_CRYPTO_DEBUG, "tag_check: %s",
-	    format_hex (tag_check, sizeof(tag_check), 0, &gc));
-	CRYPT_ERROR ("packet authentication failed");
-      }
-  }
-
-  /* Check replay */
-  if (!(opt->flags & CO_IGNORE_PACKET_ID))
+    /* Check replay */
+    if (!(opt->flags & CO_IGNORE_PACKET_ID))
     {
-      struct packet_id_net pin;
-      struct buffer tmp = *src;
-      ASSERT (buf_advance (&tmp, TLS_CRYPT_OFF_PID));
-      ASSERT (packet_id_read (&pin, &tmp, true));
-      if (!crypto_check_replay (opt, &pin, error_prefix, &gc))
-	{
-	  CRYPT_ERROR ("packet replay");
-	}
+        struct packet_id_net pin;
+        struct buffer tmp = *src;
+        ASSERT(buf_advance(&tmp, TLS_CRYPT_OFF_PID));
+        ASSERT(packet_id_read(&pin, &tmp, true));
+        if (!crypto_check_replay(opt, &pin, error_prefix, &gc))
+        {
+            CRYPT_ERROR("packet replay");
+        }
     }
 
-  gc_free (&gc);
-  return true;
+    gc_free(&gc);
+    return true;
 
- error_exit:
-  crypto_clear_error();
-  dst->len = 0;
-  gc_free (&gc);
-  return false;
+error_exit:
+    crypto_clear_error();
+    dst->len = 0;
+    gc_free(&gc);
+    return false;
 }
 
 #endif /* EMABLE_CRYPTO */