I was looking at changing announce-gen to use SHA-256 and SHA3-256
instead of SHA-1 and SHA-256. That lead me to discovering the following:
$ cksum -a sha3 --length=256 --base64 --untagged \
Makefile > Makefile.sum
$ cksum -a sha3 --check Makefile.sum
cksum: Makefile.sum: no properly formatted checksum lines found
The same issue exists for --algorithm=sha2. This patch fixes it:
$ ./src/cksum -a sha3 --check Makefile.sum
Makefile: OK
$ sed 's|[[:graph:]] Makefile$| Makefile|g' \
Makefile.sum > truncated
$ ./src/cksum -a sha3 --check truncated
cksum: truncated: no properly formatted checksum lines found
I left the behavior the same for blake2b since 'b2sum' does not support
--base64. I'm not sure if 'cksum -a blake2b' and 'b2sum' should differ
in this case...
Collin
>From bd5afe3ada0fadc4b47b27725dbf06ee0f50999e Mon Sep 17 00:00:00 2001
Message-ID: <bd5afe3ada0fadc4b47b27725dbf06ee0f50999e.1759624110.git.collin.fu...@gmail.com>
From: Collin Funk <[email protected]>
Date: Sat, 4 Oct 2025 17:18:01 -0700
Subject: [PATCH] cksum: allow --algorithm={sha2,sha3} --check to work on
base64
* NEWS: Mention the bug.
* src/digest.c (split_3): Check for the number of base64 characters.
* tests/cksum/cksum-base64-untagged.sh: New file.
* tests/local.mk (all_tests): Add the new test.
---
NEWS | 5 ++++
src/digest.c | 22 ++++++++++++--
tests/cksum/cksum-base64-untagged.sh | 43 ++++++++++++++++++++++++++++
tests/local.mk | 1 +
4 files changed, 68 insertions(+), 3 deletions(-)
create mode 100755 tests/cksum/cksum-base64-untagged.sh
diff --git a/NEWS b/NEWS
index b8c4ed4ef..2fa8464dd 100644
--- a/NEWS
+++ b/NEWS
@@ -15,6 +15,11 @@ GNU coreutils NEWS -*- outline -*-
that use the GNU extension /NUM or +NUM formats.
[bug introduced in coreutils-8.28]
+ 'cksum --algorithm={sha2,sha3} --check' can now operate on files
+ generated using 'cksum --algorithm={sha2,sha3} --base64 --untagged'.
+ [bug introduced in coreutils-9.8]
+
+
** Improvements
wc -l now operates 10% faster on hosts that support AVX512 instructions.
diff --git a/src/digest.c b/src/digest.c
index ce0e222e1..2f6daf23a 100644
--- a/src/digest.c
+++ b/src/digest.c
@@ -930,15 +930,31 @@ split_3 (char *s, size_t s_len,
# endif
unsigned char const *hp = *digest;
digest_hex_bytes = 0;
- while (c_isxdigit (*hp++))
- digest_hex_bytes++;
+ for (; c_isxdigit (*hp); ++hp, ++digest_hex_bytes)
+ ;
# if HASH_ALGO_CKSUM
+ /* Check the number of base64 characters. This works because the hexadecimal
+ character set is a subset of the base64 character set. */
+ size_t digest_base64_bytes = digest_hex_bytes;
+ for (; isubase64 (*hp) || *hp == '='; ++hp, ++digest_base64_bytes)
+ ;
if ((cksum_algorithm == sha2 || cksum_algorithm == sha3)
&& digest_hex_bytes / 2 != SHA224_DIGEST_SIZE
&& digest_hex_bytes / 2 != SHA256_DIGEST_SIZE
&& digest_hex_bytes / 2 != SHA384_DIGEST_SIZE
&& digest_hex_bytes / 2 != SHA512_DIGEST_SIZE)
- return false;
+ {
+ if (digest_base64_bytes == BASE64_LENGTH (SHA224_DIGEST_SIZE))
+ digest_hex_bytes = SHA224_DIGEST_SIZE * 2;
+ else if (digest_base64_bytes == BASE64_LENGTH (SHA256_DIGEST_SIZE))
+ digest_hex_bytes = SHA256_DIGEST_SIZE * 2;
+ else if (digest_base64_bytes == BASE64_LENGTH (SHA384_DIGEST_SIZE))
+ digest_hex_bytes = SHA384_DIGEST_SIZE * 2;
+ else if (digest_base64_bytes == BASE64_LENGTH (SHA512_DIGEST_SIZE))
+ digest_hex_bytes = SHA512_DIGEST_SIZE * 2;
+ else
+ return false;
+ }
# endif
if (digest_hex_bytes < 2 || digest_hex_bytes % 2
|| DIGEST_MAX_LEN * 2 < digest_hex_bytes)
diff --git a/tests/cksum/cksum-base64-untagged.sh b/tests/cksum/cksum-base64-untagged.sh
new file mode 100755
index 000000000..0e2eb9cb8
--- /dev/null
+++ b/tests/cksum/cksum-base64-untagged.sh
@@ -0,0 +1,43 @@
+#!/bin/sh
+# Test that cksum can guess the digest length from base64 checksums.
+
+# Copyright (C) 2025 Free Software Foundation, Inc.
+
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+
+# You should have received a copy of the GNU General Public License
+# along with this program. If not, see <https://www.gnu.org/licenses/>.
+
+. "${srcdir=.}/tests/init.sh"; path_prepend_ ./src
+print_ver_ cksum
+getlimits_
+
+echo 'test input' > inp
+echo 'inp: OK' > expout
+echo 'cksum: truncated: no properly formatted checksum lines found' > experr
+
+for algorithm in sha2 sha3; do
+ for length in 224 256 384 512; do
+ # Create files with base64 checksums in the untagged format.
+ cksum -a $algorithm --length $length --base64 --untagged inp \
+ > check || fail=1
+ # Check that the length can be determined from the base64 checksum.
+ cksum -a $algorithm --check check > out || fail=1
+ compare expout out || fail=1
+ # Check that only valid lengths are supported.
+ sed 's|[[:graph:]] inp$| inp|g' check > truncated || fail=1
+ cp truncated $HOME
+ returns_ 1 cksum -a $algorithm --check truncated 2> err || fail=1
+ compare experr err || fail=1
+ done
+done
+
+Exit $fail
diff --git a/tests/local.mk b/tests/local.mk
index 19bc194fb..52184b7ac 100644
--- a/tests/local.mk
+++ b/tests/local.mk
@@ -305,6 +305,7 @@ all_tests = \
tests/cksum/cksum-a.sh \
tests/cksum/cksum-c.sh \
tests/cksum/cksum-base64.pl \
+ tests/cksum/cksum-base64-untagged.sh \
tests/cksum/cksum-raw.sh \
tests/misc/comm.pl \
tests/csplit/csplit.sh \
--
2.51.0
