pub/, progs/: Add support for X448 key exchange, defined in RFC7748.

[catacomb] / progs / key.1

diff --git a/progs/key.1 b/progs/key.1
index a2ac337..95eb0de 100644 (file)
--- a/progs/key.1
+++ b/progs/key.1
@@ -373,9 +373,8 @@ The length of the subsidiary key or parameter, in bits.  Not all
 key-generation algorithms have a subsidiary key size.
 .TP
 .BI "\-p, \-\-parameters " tag
-Selects a key containing parameter values to copy.  Not all
-key-generation algorithms allow the use of shared parameters.  A new key
-also inherits attributes from its parameter key.
+Selects a key containing parameter values to copy.
+A new key also inherits attributes from its parameter key.
 .TP
 .BI "\-A, \-\-seedalg " seed-alg
 Use the deterministic random number generator algorithm
@@ -846,6 +845,35 @@ the public point is then
 .I x
 \(mu
 .IR G .
+.TP
+.B x25519
+Generate a private scalar and a corresponding public point on the
+(Montgomery-form) Curve25519 elliptic curve.
+The scalar is simply a random 256-bit string;
+the public key is the
+.IR x -coordinate
+of the corresponding point.
+.TP
+.B x448
+Generate a private scalar and a corresponding public point on the
+(Montgomery-form) Ed448-Goldilocks elliptic curve.
+The scalar is simply a random 256-bit string;
+the public key is the
+.IR x -coordinate
+of the corresponding point.
+.TP
+.B ed25519
+Generate a private key and a corresponding public point on the
+(twisted Edwards-form) Curve25519 elliptic curve.
+The private key is simply a random 256-bit string,
+from which a scalar and secret prefix are derived;
+the public key is the compressed form of the corresponding point.
+.TP
+.B empty
+Generate an empty key, with trivial contents.
+This is useful as a `parameters' key,
+carrying attributes to be applied to other keys
+if they don't require more detailed parameters.
 .SS "expire"
 Forces keys to immediately expire.  An expired key is not chosen when a
 program requests a key by its type.  The keys to expire are listed by