From 5ba63ec41a6e734c9ff82e20e4f84ac94c59ae27 Mon Sep 17 00:00:00 2001 From: NIIBE Yutaka Date: Fri, 10 Apr 2026 16:58:57 +0900 Subject: [PATCH] cipher:ecc: Fix decoding a point on Montgomery curve. * cipher/ecc-misc.c (_gcry_ecc_mont_decodepoint): Fix the padding mistake and add updating RAWMPILEN. -- Reported by Calif.io in collaboration with Claude and Anthropic Research. GnuPG-bug-id: 8211 Fixes-commit: bbe15758c893dbf546416c1a6bccdad1ab000ad7 Suggested-by: Bronson Yen Signed-off-by: NIIBE Yutaka --- cipher/ecc-misc.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/cipher/ecc-misc.c b/cipher/ecc-misc.c index 0c387c27..be4e2862 100644 --- a/cipher/ecc-misc.c +++ b/cipher/ecc-misc.c @@ -324,7 +324,10 @@ _gcry_ecc_mont_decodepoint (gcry_mpi_t pk, mpi_ec_t ctx, mpi_point_t result) *--p = *buf++; if (rawmpilen < nbytes) - memset (rawmpi + nbytes - rawmpilen, 0, nbytes - rawmpilen); + { + memset (rawmpi + rawmpilen, 0, nbytes - rawmpilen); + rawmpilen = nbytes; + } } else { -- 2.54.0