use mirage-crypto Z_extra

This commit is contained in:
swrup 2026-02-12 14:21:50 +01:00
parent 1679579bdb
commit 9040094717
3 changed files with 63 additions and 111 deletions

View file

@ -1,9 +1,6 @@
open Syntax open Syntax
module Binary_format_rsa = struct module Binary_format_rsa = struct
(* TODO tests:
- need to strip leading zeros?
- endianess ok? *)
(* RSA public key binary format (* RSA public key binary format
https://www.gnupg.org/documentation/manuals/gcrypt/MPI-formats.html https://www.gnupg.org/documentation/manuals/gcrypt/MPI-formats.html
:= { uint16_be: n size; uint16_be: e size; n; e} := { uint16_be: n size; uint16_be: e size; n; e}
@ -12,19 +9,9 @@ module Binary_format_rsa = struct
leading zeroes are stripped unless they are required to keep a value positive leading zeroes are stripped unless they are required to keep a value positive
no 0-termination *) no 0-termination *)
let rev_string len s = String.init len (fun i -> s.[len - 1 - i])
(* we reverse bytes because Z.of_bits reads bytes in little endian *)
let z_of_bits_be src pos len =
String.sub src pos len |> rev_string len |> Z.of_bits
let z_to_bits_be z =
let bits = Z.to_bits z in
rev_string (String.length bits) bits
let z_array_to_octets (arr : Z.t array) = let z_array_to_octets (arr : Z.t array) =
let nb = Array.length arr in let nb = Array.length arr in
let bits_arr = Array.map z_to_bits_be arr in let bits_arr = Array.map Mirage_crypto_pk.Z_extra.to_octets_be arr in
let len_arr = Array.map String.length bits_arr in let len_arr = Array.map String.length bits_arr in
let len = (2 * nb) + Array.fold_left ( + ) 0 len_arr in let len = (2 * nb) + Array.fold_left ( + ) 0 len_arr in
let b = Bytes.make len '\x00' in let b = Bytes.make len '\x00' in
@ -42,32 +29,29 @@ module Binary_format_rsa = struct
bits_arr; bits_arr;
Bytes.unsafe_to_string b Bytes.unsafe_to_string b
let check = function
| false -> Error "rsa of_octets error, invalid data"
| true -> Ok ()
let z_array_of_octets ~nb s = let z_array_of_octets ~nb s =
let s_len = String.length s in let s_len = String.length s in
let* () = check (s_len > 2 * nb) in if s_len <= 2 * nb then Error "rsa of_octets error"
let pos = ref 0 in else
let len_arr = let pos = ref 0 in
Array.init nb (fun _i -> let len_arr =
let len = String.get_uint16_be s !pos in Array.init nb (fun _i ->
pos := !pos + 2; let len = String.get_uint16_be s !pos in
len) pos := !pos + 2;
in len)
let* () = in
let len = (2 * nb) + Array.fold_left ( + ) 0 len_arr in let len = (2 * nb) + Array.fold_left ( + ) 0 len_arr in
check (s_len = len) if s_len <> len then Error "rsa of_octets error"
in else
let z_arr = let z_arr =
Array.init nb (fun i -> Array.init nb (fun i ->
let len = len_arr.(i) in let len = len_arr.(i) in
let z = z_of_bits_be s !pos len in let s = String.sub s !pos len in
pos := !pos + len; let z = Mirage_crypto_pk.Z_extra.of_octets_be s in
z) pos := !pos + len;
in z)
Ok z_arr in
Ok z_arr
let pub_to_octets ({ n; e } : Mirage_crypto_pk.Rsa.pub) = let pub_to_octets ({ n; e } : Mirage_crypto_pk.Rsa.pub) =
z_array_to_octets [| n; e |] z_array_to_octets [| n; e |]

View file

@ -1,9 +1,6 @@
open Syntax open Syntax
module Binary_format_rsa = struct module Binary_format_rsa = struct
(* TODO tests:
- need to strip leading zeros?
- endianess ok? *)
(* RSA public key binary format (* RSA public key binary format
https://www.gnupg.org/documentation/manuals/gcrypt/MPI-formats.html https://www.gnupg.org/documentation/manuals/gcrypt/MPI-formats.html
:= { uint16_be: n size; uint16_be: e size; n; e} := { uint16_be: n size; uint16_be: e size; n; e}
@ -12,19 +9,9 @@ module Binary_format_rsa = struct
leading zeroes are stripped unless they are required to keep a value positive leading zeroes are stripped unless they are required to keep a value positive
no 0-termination *) no 0-termination *)
let rev_string len s = String.init len (fun i -> s.[len - 1 - i])
(* we reverse bytes because Z.of_bits reads bytes in little endian *)
let z_of_bits_be src pos len =
String.sub src pos len |> rev_string len |> Z.of_bits
let z_to_bits_be z =
let bits = Z.to_bits z in
rev_string (String.length bits) bits
let z_array_to_octets (arr : Z.t array) = let z_array_to_octets (arr : Z.t array) =
let nb = Array.length arr in let nb = Array.length arr in
let bits_arr = Array.map z_to_bits_be arr in let bits_arr = Array.map Mirage_crypto_pk.Z_extra.to_octets_be arr in
let len_arr = Array.map String.length bits_arr in let len_arr = Array.map String.length bits_arr in
let len = (2 * nb) + Array.fold_left ( + ) 0 len_arr in let len = (2 * nb) + Array.fold_left ( + ) 0 len_arr in
let b = Bytes.make len '\x00' in let b = Bytes.make len '\x00' in
@ -42,32 +29,29 @@ module Binary_format_rsa = struct
bits_arr; bits_arr;
Bytes.unsafe_to_string b Bytes.unsafe_to_string b
let check = function
| false -> Error "rsa of_octets error, invalid data"
| true -> Ok ()
let z_array_of_octets ~nb s = let z_array_of_octets ~nb s =
let s_len = String.length s in let s_len = String.length s in
let* () = check (s_len > 2 * nb) in if s_len <= 2 * nb then Error "rsa of_octets error"
let pos = ref 0 in else
let len_arr = let pos = ref 0 in
Array.init nb (fun _i -> let len_arr =
let len = String.get_uint16_be s !pos in Array.init nb (fun _i ->
pos := !pos + 2; let len = String.get_uint16_be s !pos in
len) pos := !pos + 2;
in len)
let* () = in
let len = (2 * nb) + Array.fold_left ( + ) 0 len_arr in let len = (2 * nb) + Array.fold_left ( + ) 0 len_arr in
check (s_len = len) if s_len <> len then Error "rsa of_octets error"
in else
let z_arr = let z_arr =
Array.init nb (fun i -> Array.init nb (fun i ->
let len = len_arr.(i) in let len = len_arr.(i) in
let z = z_of_bits_be s !pos len in let s = String.sub s !pos len in
pos := !pos + len; let z = Mirage_crypto_pk.Z_extra.of_octets_be s in
z) pos := !pos + len;
in z)
Ok z_arr in
Ok z_arr
let pub_to_octets ({ n; e } : Mirage_crypto_pk.Rsa.pub) = let pub_to_octets ({ n; e } : Mirage_crypto_pk.Rsa.pub) =
z_array_to_octets [| n; e |] z_array_to_octets [| n; e |]

View file

@ -1,9 +1,6 @@
open Syntax open Syntax
module Binary_format_rsa = struct module Binary_format_rsa = struct
(* TODO tests:
- need to strip leading zeros?
- endianess ok? *)
(* RSA public key binary format (* RSA public key binary format
https://www.gnupg.org/documentation/manuals/gcrypt/MPI-formats.html https://www.gnupg.org/documentation/manuals/gcrypt/MPI-formats.html
:= { uint16_be: n size; uint16_be: e size; n; e} := { uint16_be: n size; uint16_be: e size; n; e}
@ -12,19 +9,9 @@ module Binary_format_rsa = struct
leading zeroes are stripped unless they are required to keep a value positive leading zeroes are stripped unless they are required to keep a value positive
no 0-termination *) no 0-termination *)
let rev_string len s = String.init len (fun i -> s.[len - 1 - i])
(* we reverse bytes because Z.of_bits reads bytes in little endian *)
let z_of_bits_be src pos len =
String.sub src pos len |> rev_string len |> Z.of_bits
let z_to_bits_be z =
let bits = Z.to_bits z in
rev_string (String.length bits) bits
let z_array_to_octets (arr : Z.t array) = let z_array_to_octets (arr : Z.t array) =
let nb = Array.length arr in let nb = Array.length arr in
let bits_arr = Array.map z_to_bits_be arr in let bits_arr = Array.map Mirage_crypto_pk.Z_extra.to_octets_be arr in
let len_arr = Array.map String.length bits_arr in let len_arr = Array.map String.length bits_arr in
let len = (2 * nb) + Array.fold_left ( + ) 0 len_arr in let len = (2 * nb) + Array.fold_left ( + ) 0 len_arr in
let b = Bytes.make len '\x00' in let b = Bytes.make len '\x00' in
@ -42,32 +29,29 @@ module Binary_format_rsa = struct
bits_arr; bits_arr;
Bytes.unsafe_to_string b Bytes.unsafe_to_string b
let check = function
| false -> Error "rsa of_octets error, invalid data"
| true -> Ok ()
let z_array_of_octets ~nb s = let z_array_of_octets ~nb s =
let s_len = String.length s in let s_len = String.length s in
let* () = check (s_len > 2 * nb) in if s_len <= 2 * nb then Error "rsa of_octets error"
let pos = ref 0 in else
let len_arr = let pos = ref 0 in
Array.init nb (fun _i -> let len_arr =
let len = String.get_uint16_be s !pos in Array.init nb (fun _i ->
pos := !pos + 2; let len = String.get_uint16_be s !pos in
len) pos := !pos + 2;
in len)
let* () = in
let len = (2 * nb) + Array.fold_left ( + ) 0 len_arr in let len = (2 * nb) + Array.fold_left ( + ) 0 len_arr in
check (s_len = len) if s_len <> len then Error "rsa of_octets error"
in else
let z_arr = let z_arr =
Array.init nb (fun i -> Array.init nb (fun i ->
let len = len_arr.(i) in let len = len_arr.(i) in
let z = z_of_bits_be s !pos len in let s = String.sub s !pos len in
pos := !pos + len; let z = Mirage_crypto_pk.Z_extra.of_octets_be s in
z) pos := !pos + len;
in z)
Ok z_arr in
Ok z_arr
let pub_to_octets ({ n; e } : Mirage_crypto_pk.Rsa.pub) = let pub_to_octets ({ n; e } : Mirage_crypto_pk.Rsa.pub) =
z_array_to_octets [| n; e |] z_array_to_octets [| n; e |]