init

src/crypto.ml

@@ -0,0 +1,159 @@
+(* TODO key format
+   - check what is the exact format in GNUNET
+   - endianess issue? *)
+module EddsaPublicKey = struct
+  (* EdDSA and ECDHE public keys always point on Curve25519
+     and represented  using the standard 256 bits Ed25519 compact format,
+     converted to Crockford Base32. *)
+  open Mirage_crypto_ec.Ed25519
+
+  type t = pub
+
+  let to_octets t = pub_to_octets t
+  let of_octets t = pub_of_octets t |> Result.get_ok
+  let bin = Bin.map (Bin.bytes 32) of_octets to_octets
+
+  let of_b32 s =
+    let open Syntax in
+    let* octets = B32.decode s in
+    match pub_of_octets octets with
+    | Error e -> Fmt.error "%a" Mirage_crypto_ec.pp_error e
+    | Ok pub -> Ok pub
+
+  let to_b32 t = B32.encode (to_octets t)
+  let jsont = Jsont.of_of_string ~kind:"EddsaPublicKey" of_b32 ~enc:to_b32
+end
+
+module EddsaPrivateKey = struct
+  (* EdDSA and ECDHE public keys always point on Curve25519
+     and represented  using the standard 256 bits Ed25519 compact format,
+     converted to Crockford Base32. *)
+  open Mirage_crypto_ec.Ed25519
+
+  type t = priv
+
+  let pub_of_priv = pub_of_priv
+  let to_octets t = priv_to_octets t
+  let of_octets t = priv_of_octets t |> Result.get_ok
+  let bin = Bin.map (Bin.bytes 32) of_octets to_octets
+
+  let of_b32 s =
+    let open Syntax in
+    let* octets = B32.decode s in
+    match priv_of_octets octets with
+    | Error e -> Fmt.error "%a" Mirage_crypto_ec.pp_error e
+    | Ok priv -> Ok priv
+
+  let to_b32 t = B32.encode (to_octets t)
+  let jsont = Jsont.of_of_string ~kind:"EddsaPrivateKey" of_b32 ~enc:to_b32
+end
+
+module EddsaSignature : sig
+  type t
+
+  val sign : key:Mirage_crypto_ec.Ed25519.priv -> string -> t
+  val sign_as_string : key:Mirage_crypto_ec.Ed25519.priv -> string -> string
+  val of_b32 : string -> (t, string) result
+  val to_b32 : t -> string
+  val to_octets : t -> string
+  val of_octets : string -> t
+  val jsont : t Jsont.t
+  val bin : t Bin.t
+end = struct
+  (* TODO key format
+     endianess issue? *)
+  (* EdDSA signatures are transmitted as 64-bytes base32
+     binary-encoded objects with just the R and S values (base32_ binary-only).
+
+     They are signature over a c-struct like `TALER_xxxPS` + with a purpose *)
+  type t = string
+
+  let to_octets t = t
+
+  let of_octets v =
+    match String.length v = 64 with
+    | false ->
+        Fmt.failwith "EddsaSignature.of_octets failure: data is not 64 bytes."
+    | true -> v
+
+  let bin = Bin.map (Bin.bytes 64) of_octets to_octets
+
+  let sign ~key s =
+    (* mirage_crypto: "The result is the concatenation of r and s, as specified in RFC 8032." *)
+    Mirage_crypto_ec.Ed25519.sign ~key s
+
+  let sign_as_string ~key s = sign ~key s
+
+  let check_size t =
+    match String.length t = 64 with
+    | false -> Error "EddsaSignature: invalid string length"
+    | true -> Ok ()
+
+  let of_b32 s =
+    let open Syntax in
+    let* t = B32.decode s in
+    let+ () = check_size t in
+    t
+
+  let to_b32 = B32.encode
+  let jsont = Jsont.of_of_string ~kind:"EddsaSignature" of_b32 ~enc:to_b32
+end
+
+module RsaPublicKey = struct
+  open Mirage_crypto_pk
+
+  type t = Rsa.pub
+
+  let of_octets = Util.Bin_rsa.pub_of_octets
+  let to_octets = Util.Bin_rsa.pub_to_octets
+
+  let of_b32 s =
+    let open Syntax in
+    let* s = B32.decode s in
+    let v = Util.Bin_rsa.pub_of_octets s in
+    let+ v = Rsa.pub ~n:v.n ~e:v.e |> unwrap_err_msg in
+    v
+
+  let to_b32 t = B32.encode (to_octets t)
+  let jsont = Jsont.of_of_string ~kind:"RsaPublicKey" of_b32 ~enc:to_b32
+end
+
+module RsaPrivateKey = struct
+  open Mirage_crypto_pk.Rsa
+
+  type t = priv
+
+  let pub_of_priv = pub_of_priv
+  let of_octets = Util.Bin_rsa.priv_of_octets
+  let to_octets = Util.Bin_rsa.priv_to_octets
+
+  let of_b32 s =
+    let open Syntax in
+    let* s = B32.decode s in
+    Ok (of_octets s)
+
+  let to_b32 t = B32.encode (to_octets t)
+  let jsont = Jsont.of_of_string ~kind:"RsaPrivateKey" of_b32 ~enc:to_b32
+end
+
+module RsaSignature : sig
+  type t
+
+  val to_octets : t -> string
+  val sign : key:Mirage_crypto_pk.Rsa.priv -> string -> t
+  val of_b32 : string -> (t, string) result
+  val to_b32 : t -> string
+  val jsont : t Jsont.t
+end = struct
+  type t = string
+
+  let to_octets t = t
+
+  (* TODO rsa sign *)
+  let sign ~key s =
+    Mirage_crypto_pk.Rsa.decrypt ~crt_hardening:true ~mask:`Yes ~key s
+
+  let of_b32 s = B32.decode s
+  let to_b32 t = B32.encode t
+  let jsont = Jsont.of_of_string ~kind:"RsaSignature" of_b32 ~enc:to_b32
+end