objective categorical abstract machine language personal data server
Fix low-s signature normalization not occurring
+76
-4
+4
-4
kleidos/kleidos.ml
+4
-4
kleidos/kleidos.ml
···
78
78
let hashed = SHA2_256.hash msg in
79
79
let k = Rfc6979.k_for_k256 ~privkey ~msg in
80
80
match K256.Libsecp256k1.sign ~sk:privkey ~msg:hashed ~k with
81
-
| Some signature ->
82
-
signature
81
+
| Some sgn ->
82
+
Low_s.normalize_k256 sgn
83
83
| None ->
84
84
failwith "failed to sign message"
85
85
···
146
146
let hashed = SHA2_256.hash msg in
147
147
let k = Rfc6979.k_for_p256 ~privkey ~msg in
148
148
match P256.sign ~sk:privkey ~msg:hashed ~k with
149
-
| Some signature ->
150
-
signature
149
+
| Some sgn ->
150
+
Low_s.normalize_p256 sgn
151
151
| None ->
152
152
failwith "failed to sign message"
153
153
+56
kleidos/low_s.ml
+56
kleidos/low_s.ml
···
1
+
open struct
2
+
let z_of_bytes s =
3
+
let acc = ref Z.zero in
4
+
for i = 0 to String.length s - 1 do
5
+
acc := Z.(shift_left !acc 8 + of_int (Char.code s.[i]))
6
+
done ;
7
+
!acc
8
+
9
+
let bytes_of_z_32 z =
10
+
let buf = Bytes.make 32 '\x00' in
11
+
let rec fill i v =
12
+
if i >= 0 then (
13
+
Bytes.set buf i (Char.chr (Z.to_int (Z.logand v (Z.of_int 0xff)))) ;
14
+
fill (i - 1) (Z.shift_right v 8) )
15
+
in
16
+
fill 31 z ; Bytes.unsafe_to_string buf
17
+
18
+
let to_32 s =
19
+
let l = String.length s in
20
+
if l = 32 then s
21
+
else if l < 32 then String.make (32 - l) '\x00' ^ s
22
+
else String.sub s (l - 32) 32
23
+
end
24
+
25
+
let normalize ~(order : Z.t) (r : string) (s : string) : bytes =
26
+
let r32 = to_32 r in
27
+
let s32 = to_32 s in
28
+
let s_z = z_of_bytes s32 in
29
+
let s_low = if Z.gt s_z Z.(order / ~$2) then Z.(order - s_z) else s_z in
30
+
r32 ^ bytes_of_z_32 s_low |> Bytes.of_string
31
+
32
+
let k256_n =
33
+
Z.of_string
34
+
"0xFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFFEBAAEDCE6AF48A03BBFD25E8CD0364141"
35
+
36
+
let p256_n =
37
+
Z.of_string
38
+
"0xFFFFFFFF00000000FFFFFFFFFFFFFFFFBCE6FAADA7179E84F3B9CAC2FC632551"
39
+
40
+
let rs_of_sig (signature : bytes) : string * string =
41
+
let sig_str = Bytes.to_string signature in
42
+
let sig_len = String.length sig_str in
43
+
if sig_len <> 64 then
44
+
invalid_arg
45
+
(Format.sprintf "signature must be 64 bytes (r||s); got %d" sig_len) ;
46
+
let r = String.sub sig_str 0 32 in
47
+
let s = String.sub sig_str 32 32 in
48
+
(r, s)
49
+
50
+
let normalize_k256 sgn =
51
+
let r, s = rs_of_sig sgn in
52
+
normalize ~order:k256_n r s
53
+
54
+
let normalize_p256 sgn =
55
+
let r, s = rs_of_sig sgn in
56
+
normalize ~order:p256_n r s
+3
pegasus/lib/plc.ml
+3
pegasus/lib/plc.ml
+13
pegasus/lib/util.ml
+13
pegasus/lib/util.ml
···
310
310
let mkfile_p path ~perm =
311
311
Core_unix.mkdir_p (Filename.dirname path) ~perm:0o755 ;
312
312
Core_unix.openfile ~mode:[O_CREAT; O_WRONLY] ~perm path |> Core_unix.close
313
+
314
+
let sig_matches_some_did_key ~did_keys ~signature ~msg =
315
+
List.find_opt
316
+
(fun key ->
317
+
let raw, (module Curve) =
318
+
Kleidos.parse_multikey_str (String.sub key 8 (String.length key - 8))
319
+
in
320
+
let valid =
321
+
Curve.verify ~pubkey:(Curve.normalize_pubkey_to_raw raw) ~signature ~msg
322
+
in
323
+
valid )
324
+
did_keys
325
+
<> None