Yet another article on russian, mentioning GoVPN

[govpn.git] / doc / handshake.texi

diff --git a/doc/handshake.texi b/doc/handshake.texi
index c15e45643857004d2ae4f07b3fe97339fcff7ef8..75a65085f712082136675d6b34dc54860db1cd54 100644 (file)
--- a/doc/handshake.texi
+++ b/doc/handshake.texi
@@ -3,28 +3,29 @@
 
 @verbatiminclude handshake.utxt
 
-Each handshake message ends with so called @code{IDtag}: it is an XTEA
-encrypted first 64 bits of each message with client's @ref{Identity} as
-a key. It is used to transmit identity and to mark packet as handshake
-message.
+Each handshake message ends with so called @code{IDtag}: it is
+BLAKE2b-MAC of the first 64 bits of the handshake message, with client's
+@ref{Identity} used as a key. It is used to transmit identity and to
+mark packet as handshake message.
 
-If @ref{Noise} is enabled, then junk data is inserted before
-@code{IDtag} to full up packet to MTU's size.
+If @ref{Noise, noise} is enabled, then data is padded to fill up packet
+to MTU's size.
 
 @strong{Preparation stage}:
 
 @enumerate
 @item
 Client knows only his identity and passphrase written somewhere in the
-human. Server knows his identity and
+human readable form. Server knows his identity and
 @ref{Verifier structure, verifier}: @code{DSAPub}.
 @item
 Client computes verifier which produces @code{DSAPriv} and
-@code{DSAPub}. @code{H()} is @emph{HSalsa20} hash function.
+@code{DSAPub}. @code{H()} is @emph{BLAKE2b-256} hash function.
 @item
 Client generates DH keypair: @code{CDHPub} and @code{CDHPriv}.
 Also it generates random 64-bit @code{R} that is used as a nonce for
-symmetric encryption. @code{El()} is Elligator point encoding algorithm.
+symmetric encryption. @code{El()} is Elligator point encoding (and vice
+versa) algorithm.
 @end enumerate
 
 @strong{Interaction stage}:
@@ -34,7 +35,7 @@ symmetric encryption. @code{El()} is Elligator point encoding algorithm.
 @verb{|R + enc(H(DSAPub), R, El(CDHPub)) + IDtag -> Server|} [48 bytes]
 
 @item
-@itemize @bullet
+@itemize
 @item Server remembers client address.
 @item Decrypts @code{El(CDHPub)}.
 @item Inverts @code{El()} encoding and gets @code{CDHPub}.
@@ -48,7 +49,7 @@ symmetric encryption. @code{El()} is Elligator point encoding algorithm.
 @verb{|enc(H(DSAPub), R+1, El(SDHPub)) + enc(K, R, RS + SS) + IDtag -> Client|} [80 bytes]
 
 @item
-@itemize @bullet
+@itemize
 @item Client decrypts @code{El(SDHPub)}.
 @item Inverts @code{El()} encoding and gets @code{SDHPub}.
 @item Computes @code{K}.
@@ -63,7 +64,7 @@ symmetric encryption. @code{El()} is Elligator point encoding algorithm.
 @verb{|enc(K, R+1, RS + RC + SC + Sign(DSAPriv, K)) + IDtag -> Server|} [120 bytes]
 
 @item
-@itemize @bullet
+@itemize
     @item Server decrypts @code{RS}, @code{RC}, @code{SC},
     @code{Sign(DSAPriv, K)}.
 
@@ -81,7 +82,7 @@ symmetric encryption. @code{El()} is Elligator point encoding algorithm.
 @verb{|ENC(K, R+2, RC) + IDtag -> Client|} [16 bytes]
 
 @item
-@itemize @bullet
+@itemize
 @item Client decrypts @code{RC}
 @item Compares with its own one sent before.
 @item Computes final session encryption key as server did.
@@ -93,3 +94,6 @@ symmetric encryption. @code{El()} is Elligator point encoding algorithm.
 has 128-bit security margin and that is why are not in use except in
 handshake process. @code{R*} are required for handshake randomization
 and two-way authentication.
+
+In @ref{Encless, encryptionless mode} each @code{enc()} is replaced with
+AONT and chaffing function over the noised data.