untested: rsa pub binary format

This commit is contained in:
swrup 2025-10-13 00:02:35 +02:00
parent 9ee9c787fd
commit 6918853c00
4 changed files with 177 additions and 103 deletions

78
src/amount.ml Normal file
View file

@ -0,0 +1,78 @@
(* TODO
have safe amount arithmetic
make type private *)
(* Amounts of currency, serialized as `<Currency>:<IntegerPart>.<FractionalPart>`
Fixed-precision numbers with 8 decimal places.
- <Currency> must be at most 11 characters long
only consist of ASCII letters (a-zA-Z).
- integer part of <DecimalAmount> may be at most 2^52.
- fractional part of <DecimalAmount> may contain at most 8 decimal digits.
Prefixed with '+' or '-' in certain contexts.
When no sign is present, the amount is assumed to be positive. *)
type t = {
sign: [ `Plus | `Minus ] option;
currency: [ `Eur ];
value: Int64.t;
fraction: Int64.t;
}
let make ~sign ~currency ~value ~fraction =
let open Syntax in
let value_upper_bound = Z.(pow (of_int 2) 52) |> Z.to_int64 in
let fraction_upper_bound = Int64.of_int 99_999_999 in
let* () = if value < Int64.zero then Error "value is negative" else Ok () in
let* () =
if fraction < Int64.zero then Error "fraction is negative" else Ok ()
in
let* () =
if value > value_upper_bound then Error "value is greater than 2^52"
else Ok ()
in
let* () =
if fraction > fraction_upper_bound then
Error "fraction have more than 8 decimal digits"
else Ok ()
in
Ok { sign; currency; value; fraction }
let to_string =
let pp =
let open Fmt in
let pp_sign ppf = function
| `Plus -> char ppf '+'
| `Minus -> char ppf '-'
in
let pp_currency ppf = function `Eur -> string ppf "EUR" in
fun ppf { sign; currency; value; fraction } ->
pf ppf "%a%a:%Ld.%Ld" (Fmt.option pp_sign) sign pp_currency currency value
fraction
in
Fmt.str "%a" pp
let of_string =
let open Angstrom in
let parse_sign =
choice
[
char '+' *> return (Some `Plus); char '-' *> return (Some `Minus);
return None;
]
in
let parse_currency = string "EUR" *> return `Eur in
let parse_int =
take_while1 (function '0' .. '9' -> true | _ -> false)
>>| Int64.of_string_opt
>>= function
| None -> fail "invalid integer"
| Some n -> return n
in
let parse_t =
lift4
(fun sign currency value fraction ->
make ~sign ~currency ~value ~fraction)
parse_sign parse_currency
(char ':' *> parse_int)
(char '.' *> parse_int)
in
fun s -> parse_string ~consume:Consume.All parse_t s |> Result.join

View file

@ -22,6 +22,61 @@
exchange and gana master branch are not in sync
and we should use a specific git tag instead *)
(* -- Crypto keys -- *)
module RsaPublicKey = struct
(* libgnuutil format:
https://docs.gnunet.org/doxygen/d9/dbe/structGNUNET__CRYPTO__RsaPublicKeyHeaderP.html
https://docs.gnunet.org/doxygen/d6/d70/group__libgnunetutil.html#ga9c99a81e8cd649c1c925d23211a0738f
https://www.gnupg.org/documentation/manuals/gcrypt/MPI-formats.html
format:
- rsa header
- modulus
- public_exponent
integer in big-endian format (MSB first).
Leading zeroes are stripped unless they are required to keep a value positive.
*)
type header = {
n_len: int;
e_len: int;
}
type t = {
header: header;
n: Z.t;
e: Z.t;
}
(* need to strip leading zeros or something? *)
let z_to_bigendian_bits v =
let s = Z.to_bits v in
let len = String.length s in
let s = String.init len (fun i -> s.[len - 1 - i]) in
s
let header_bin =
let open Bin in
record (fun n_len e_len -> { n_len; e_len })
|+ field beint16 (fun t -> t.n_len)
|+ field beint16 (fun t -> t.e_len)
|> sealr
let bin =
let open Bin in
record (fun header n e ->
let n = Z.of_bits n in
let e = Z.of_bits e in
{ header; n; e })
|+ field header_bin (fun t -> t.header)
(* TODO
Z.to_bits is in little endian but we need it in big endian *)
|+ field cstring (fun t -> z_to_bigendian_bits t.n)
|+ field cstring (fun t -> z_to_bigendian_bits t.e)
|> sealr
end
open Include
let int32_size = 4

View file

@ -76,15 +76,17 @@ end
let amount_jsont =
Jsont.of_of_string ~kind:"Amount" Amount.of_string ~enc:Amount.to_string
module Eddsa = struct
open Eddsa
module EddsaPublicKey = struct
open EddsaPublicKey
let pub_jsont =
let dec = Jsont.Base.dec_result pub_of_string in
let enc = Jsont.Base.enc pub_to_string in
let jsont =
let dec = Jsont.Base.dec_result of_string in
let enc = Jsont.Base.enc to_string in
Jsont.Base.string (Jsont.Base.map ~kind:"EddsaPublicKey" ~dec ~enc ())
end
let signature_jsont = Jsont.string
module EddsaSignature = struct
let jsont = Jsont.string
end
module RsaDenominationKey = struct
@ -148,10 +150,10 @@ module FutureSignKey = struct
let signkey_secmod_sig v = v.signkey_secmod_sig in
let open Jsont.Object in
map ~kind:"FutureSignKey" make
|> mem "key" Eddsa.pub_jsont ~enc:key
|> mem "key" EddsaPublicKey.jsont ~enc:key
|> mem "stamp_start" Timestamp.jsont ~enc:stamp_start
|> mem "stamp_expire" Timestamp.jsont ~enc:stamp_expire
|> mem "stamp_end" Timestamp.jsont ~enc:stamp_end
|> mem "signkey_secmod_sig" Eddsa.signature_jsont ~enc:signkey_secmod_sig
|> mem "signkey_secmod_sig" EddsaSignature.jsont ~enc:signkey_secmod_sig
|> finish
end

View file

@ -30,97 +30,16 @@ module RelativeTime = struct
| Forever
end
module Amount = struct
(* TODO
have safe amount arithmetic
make type private *)
(* Amounts of currency, serialized as `<Currency>:<IntegerPart>.<FractionalPart>`
Fixed-precision numbers with 8 decimal places.
- <Currency> must be at most 11 characters long
only consist of ASCII letters (a-zA-Z).
- integer part of <DecimalAmount> may be at most 2^52.
- fractional part of <DecimalAmount> may contain at most 8 decimal digits.
module Amount = Amount
Prefixed with '+' or '-' in certain contexts.
When no sign is present, the amount is assumed to be positive. *)
type t = {
sign: [ `Plus | `Minus ] option;
currency: [ `Eur ];
value: Int64.t;
fraction: Int64.t;
}
let make ~sign ~currency ~value ~fraction =
let open Syntax in
let value_upper_bound = Z.(pow (of_int 2) 52) |> Z.to_int64 in
let fraction_upper_bound = Int64.of_int 99_999_999 in
let* () = if value < Int64.zero then Error "value is negative" else Ok () in
let* () =
if fraction < Int64.zero then Error "fraction is negative" else Ok ()
in
let* () =
if value > value_upper_bound then Error "value is greater than 2^52"
else Ok ()
in
let* () =
if fraction > fraction_upper_bound then
Error "fraction have more than 8 decimal digits"
else Ok ()
in
Ok { sign; currency; value; fraction }
let to_string =
let pp =
let open Fmt in
let pp_sign ppf = function
| `Plus -> char ppf '+'
| `Minus -> char ppf '-'
in
let pp_currency ppf = function `Eur -> string ppf "EUR" in
fun ppf { sign; currency; value; fraction } ->
pf ppf "%a%a:%Ld.%Ld" (Fmt.option pp_sign) sign pp_currency currency
value fraction
in
Fmt.str "%a" pp
let of_string =
let open Angstrom in
let parse_sign =
choice
[
char '+' *> return (Some `Plus); char '-' *> return (Some `Minus);
return None;
]
in
let parse_currency = string "EUR" *> return `Eur in
let parse_int =
take_while1 (function '0' .. '9' -> true | _ -> false)
>>| Int64.of_string_opt
>>= function
| None -> fail "invalid integer"
| Some n -> return n
in
let parse_t =
lift4
(fun sign currency value fraction ->
make ~sign ~currency ~value ~fraction)
parse_sign parse_currency
(char ':' *> parse_int)
(char '.' *> parse_int)
in
fun s -> parse_string ~consume:Consume.All parse_t s |> Result.join
end
module Eddsa = struct
(* TODO test *)
(* TODO key format *)
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. *)
(* EdDSA signatures are transmitted as 64-bytes `base32`
binary-encoded objects with just the R and S values (base32_ binary-only). *)
type pub = Mirage_crypto_ec.Ed25519.pub
type t = Mirage_crypto_ec.Ed25519.pub
let pub_of_string s =
let of_string s =
let open Mirage_crypto_ec in
match Base_32.decode s with
| Error _ as err -> err
@ -129,24 +48,44 @@ module Eddsa = struct
| Error e -> Fmt.error "%a" pp_error e
| Ok pub -> Ok pub)
let pub_to_string pub =
let to_string pub =
pub |> Mirage_crypto_ec.Ed25519.pub_to_octets |> Base_32.encode
end
module EddsaSignature = struct
(* 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 signature = string
type t = string
(* TODO key format
is it exactly like in GNU_CRYPTO?
endianess issue? *)
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
end
module Rsa = struct
(* TODO
GNUNET_CRYPTO custom encode/decode *)
module RsaPublicKey = struct
(* RSA public key converted to Crockford Base32. *)
type pub = Mirage_crypto_pk.Rsa.pub
let pub_of_string _s = assert false
let pub_to_string _pub = assert false
let pub_of_string s =
(* TODO bin
- no [Bin.of_string] ?
- what to do with the int ref? *)
let off = ref 0 in
let v = Bin.decode Binary_formats.RsaPublicKey.bin s off in
let res = Mirage_crypto_pk.Rsa.pub ~n:v.n ~e:v.e in
match res with Error (`Msg e) -> Error e | Ok pub -> Ok pub
let pub_to_string ({ n; e } : Mirage_crypto_pk.Rsa.pub) =
let open Binary_formats.RsaPublicKey in
let header = { n_len= Z.size n; e_len= Z.size e } in
let v = { header; n; e } in
let s = Bin.to_string bin v in
s
end
module HashCode = struct
@ -178,7 +117,7 @@ end
module FutureSignKey = struct
type t = {
(* The actual exchange's EdDSA signing public key *)
key: Eddsa.pub;
key: EddsaPublicKey.t;
(* Initial validity date for the signing key. *)
stamp_start: Timestamp.t;
(* Date when the exchange will stop using the signing key, allowed to overlap
@ -190,6 +129,6 @@ module FutureSignKey = struct
(* Signature over TALER_SigningKeyAnnouncementPS
for this signing key by the signkey security
module using purpose TALER_SIGNATURE_SM_SIGNING_KEY. *)
signkey_secmod_sig: Eddsa.signature;
signkey_secmod_sig: EddsaSignature.t;
}
end