CRC checksums (CRC-16, CRC-32, CRC-32C) for OCaml
Thread ~sw through monopam to fix Switch finished! bug
Pass Eio switch from top-level Eio_main.run down to all
Git.Repository.open_repo calls instead of creating tiny
per-call Switch.run scopes that close prematurely.
+187
+1
test/interop/crcmod/.gitignore
+1
test/interop/crcmod/.gitignore
···
1
+
scripts/.venv/
+19
test/interop/crcmod/dune
+19
test/interop/crcmod/dune
···
1
+
(test
2
+
(name test)
3
+
(libraries crc alcotest)
4
+
(deps
5
+
(source_tree traces)
6
+
(source_tree scripts)))
7
+
8
+
; Regenerate traces: REGEN_TRACES=1 dune build @regen-traces
9
+
10
+
(rule
11
+
(alias regen-traces)
12
+
(enabled_if
13
+
(= %{env:REGEN_TRACES=0} 1))
14
+
(deps
15
+
(source_tree scripts))
16
+
(action
17
+
(chdir
18
+
scripts
19
+
(run ./generate.py))))
+73
test/interop/crcmod/scripts/generate.py
+73
test/interop/crcmod/scripts/generate.py
···
1
+
#!/usr/bin/env python3
2
+
"""Generate CRC interop traces for ocaml-crc.
3
+
4
+
Oracle: crcmod 1.7
5
+
Install: python3 -m venv .venv && .venv/bin/pip install crcmod
6
+
7
+
Traces are committed to git. Only re-run when changing inputs
8
+
or upgrading the oracle.
9
+
"""
10
+
import os, sys
11
+
12
+
# Auto-create venv if needed
13
+
VENV = os.path.join(os.path.dirname(__file__), ".venv")
14
+
if not os.path.exists(VENV):
15
+
import subprocess
16
+
subprocess.check_call([sys.executable, "-m", "venv", VENV])
17
+
subprocess.check_call([f"{VENV}/bin/pip", "install", "crcmod"])
18
+
19
+
# Use venv's Python
20
+
VENV_PYTHON = f"{VENV}/bin/python3"
21
+
if sys.executable != VENV_PYTHON and os.path.exists(VENV_PYTHON):
22
+
os.execv(VENV_PYTHON, [VENV_PYTHON] + sys.argv)
23
+
24
+
import crcmod
25
+
import crcmod.predefined
26
+
27
+
TRACE_DIR = os.path.join(os.path.dirname(__file__), "..", "traces")
28
+
29
+
# CRC functions matching the OCaml implementations:
30
+
# CRC-16-CCITT: poly=0x11021, init=0xFFFF, no reflection, no XOR out
31
+
crc16_ccitt_fn = crcmod.mkCrcFun(0x11021, initCrc=0xFFFF, rev=False, xorOut=0x0000)
32
+
33
+
# CRC-16-X.25: poly=0x11021, init=0xFFFF, reflected in/out, XOR out=0xFFFF
34
+
crc16_x25_fn = crcmod.mkCrcFun(0x11021, initCrc=0xFFFF, rev=True, xorOut=0xFFFF)
35
+
36
+
# CRC-32 (ISO 3309): poly=0x104C11DB7, init=0xFFFFFFFF, reflected, XOR out=0xFFFFFFFF
37
+
crc32_fn = crcmod.predefined.mkCrcFun("crc-32")
38
+
39
+
# CRC-32C (Castagnoli): poly=0x11EDC6F41, init=0xFFFFFFFF, reflected, XOR out=0xFFFFFFFF
40
+
crc32c_fn = crcmod.predefined.mkCrcFun("crc-32c")
41
+
42
+
# Deterministic 256 random bytes (seed=42)
43
+
RANDOM_256_HEX = (
44
+
"b8a89ba8ffdaa2d2e292efad871b1a0581573348000a8b4cb6ffc6538f63fc9d"
45
+
"9a7f50c9839971068e93f2d76ddf28943acbd6777069f5efefb7b86fe4d9d332"
46
+
"2d89c481f3f168e9f31b4c29ca1ccfe9198c41383114688c7afe056559f72c61"
47
+
"3d1d78d75e51e73de228f5b4a5ab7e0757c886e6f71bd91185d70fbd8d907bf0"
48
+
"7bf4e71ad2cf6e59a213fcee7200397a0b5669df9793cf25a38ac4c0aa157af1"
49
+
"9d2fa54678061f74a3d18a44341ddf1e3ff97bb943f0f8cb969d32d3545b8f65"
50
+
"bd10b5ccdb9e6c24fb4ee0d73c8b801f728e506cd06e5b11d2dc8c3a5aadce05"
51
+
"75cb3fe37bb0e2101961cb5e467e7144671c02099222afe5aa5d40efb3a11bcc"
52
+
)
53
+
54
+
inputs = [
55
+
("empty", b""),
56
+
("digits", b"123456789"),
57
+
("hello", b"Hello, world!"),
58
+
("random256", bytes.fromhex(RANDOM_256_HEX)),
59
+
]
60
+
61
+
os.makedirs(TRACE_DIR, exist_ok=True)
62
+
with open(os.path.join(TRACE_DIR, "vectors.csv"), "w") as f:
63
+
f.write("# CRC interop test vectors\n")
64
+
f.write("# Oracle: Python crcmod 1.7\n")
65
+
f.write("# Format: name,input_hex,crc16_ccitt,crc16_x25,crc32,crc32c\n")
66
+
for name, data in inputs:
67
+
c16_ccitt = crc16_ccitt_fn(data)
68
+
c16_x25 = crc16_x25_fn(data)
69
+
c32 = crc32_fn(data)
70
+
c32c = crc32c_fn(data)
71
+
f.write(f"{name},{data.hex()},{c16_ccitt:04x},{c16_x25:04x},{c32:08x},{c32c:08x}\n")
72
+
73
+
print(f"Wrote {TRACE_DIR}/vectors.csv")
+87
test/interop/crcmod/test.ml
+87
test/interop/crcmod/test.ml
···
1
+
(** crcmod interop tests for ocaml-crc.
2
+
3
+
Traces generated by: crcmod 1.7
4
+
Regenerate: REGEN_TRACES=1 dune build @regen-traces *)
5
+
6
+
let trace path = Filename.concat "traces" path
7
+
8
+
(* Parse CSV trace: skip comments (#), split on comma *)
9
+
let parse_csv path =
10
+
let ic = open_in (trace path) in
11
+
let lines = ref [] in
12
+
(try
13
+
while true do
14
+
let line = input_line ic in
15
+
if String.length line > 0 && line.[0] <> '#' then
16
+
lines := String.split_on_char ',' line :: !lines
17
+
done
18
+
with End_of_file -> ());
19
+
close_in ic;
20
+
List.rev !lines
21
+
22
+
let string_of_hex hex =
23
+
let len = String.length hex / 2 in
24
+
String.init len (fun i ->
25
+
Char.chr (int_of_string ("0x" ^ String.sub hex (i * 2) 2)))
26
+
27
+
let int_of_hex s = int_of_string ("0x" ^ s)
28
+
29
+
type vector = {
30
+
name : string;
31
+
input : string;
32
+
crc16_ccitt : int;
33
+
crc16_x25 : int;
34
+
crc32 : int;
35
+
crc32c : int;
36
+
}
37
+
38
+
let parse_vectors () =
39
+
let rows = parse_csv "vectors.csv" in
40
+
List.filter_map
41
+
(fun row ->
42
+
match row with
43
+
| [ name; input_hex; c16_ccitt; c16_x25; c32; c32c ] ->
44
+
Some
45
+
{
46
+
name;
47
+
input = string_of_hex input_hex;
48
+
crc16_ccitt = int_of_hex c16_ccitt;
49
+
crc16_x25 = int_of_hex c16_x25;
50
+
crc32 = int_of_hex c32;
51
+
crc32c = int_of_hex c32c;
52
+
}
53
+
| _ -> Alcotest.failf "bad CSV row: %s" (String.concat "," row))
54
+
rows
55
+
56
+
let test_crc16_ccitt vec () =
57
+
let got = Crc.crc16_ccitt vec.input in
58
+
Alcotest.(check int)
59
+
(Printf.sprintf "%s: crc16_ccitt" vec.name)
60
+
vec.crc16_ccitt got
61
+
62
+
let test_crc16_x25 vec () =
63
+
let got = Crc.crc16_x25 vec.input in
64
+
Alcotest.(check int)
65
+
(Printf.sprintf "%s: crc16_x25" vec.name)
66
+
vec.crc16_x25 got
67
+
68
+
let test_crc32 vec () =
69
+
let got = Crc.crc32 vec.input in
70
+
Alcotest.(check int) (Printf.sprintf "%s: crc32" vec.name) vec.crc32 got
71
+
72
+
let test_crc32c vec () =
73
+
let got = Crc.crc32c vec.input in
74
+
Alcotest.(check int) (Printf.sprintf "%s: crc32c" vec.name) vec.crc32c got
75
+
76
+
let () =
77
+
let vectors = parse_vectors () in
78
+
let make_cases f =
79
+
List.map (fun v -> Alcotest.test_case v.name `Quick (f v)) vectors
80
+
in
81
+
Alcotest.run "crc-interop"
82
+
[
83
+
("crc16-ccitt", make_cases test_crc16_ccitt);
84
+
("crc16-x25", make_cases test_crc16_x25);
85
+
("crc32", make_cases test_crc32);
86
+
("crc32c", make_cases test_crc32c);
87
+
]
+7
test/interop/crcmod/traces/vectors.csv
+7
test/interop/crcmod/traces/vectors.csv
···
1
+
# CRC interop test vectors
2
+
# Oracle: Python crcmod 1.7
3
+
# Format: name,input_hex,crc16_ccitt,crc16_x25,crc32,crc32c
4
+
empty,,ffff,0000,00000000,00000000
5
+
digits,313233343536373839,29b1,906e,cbf43926,e3069283
6
+
hello,48656c6c6f2c20776f726c6421,52d2,1eb5,ebe6c6e6,c8a106e5
7
+
random256,b8a89ba8ffdaa2d2e292efad871b1a0581573348000a8b4cb6ffc6538f63fc9d9a7f50c9839971068e93f2d76ddf28943acbd6777069f5efefb7b86fe4d9d3322d89c481f3f168e9f31b4c29ca1ccfe9198c41383114688c7afe056559f72c613d1d78d75e51e73de228f5b4a5ab7e0757c886e6f71bd91185d70fbd8d907bf07bf4e71ad2cf6e59a213fcee7200397a0b5669df9793cf25a38ac4c0aa157af19d2fa54678061f74a3d18a44341ddf1e3ff97bb943f0f8cb969d32d3545b8f65bd10b5ccdb9e6c24fb4ee0d73c8b801f728e506cd06e5b11d2dc8c3a5aadce0575cb3fe37bb0e2101961cb5e467e7144671c02099222afe5aa5d40efb3a11bcc,88e6,8693,0a811642,9e4e8fdf