From 70c49ce02401b1d5d0c176feca06ca0a72e8007a Mon Sep 17 00:00:00 2001 From: NIIBE Yutaka <gniibe@fsij.org> Date: Mon, 25 Nov 2024 14:39:59 +0900 Subject: [PATCH] gpg: Fix modifying signature data by pk_verify for Ed25519. * g10/pkglue.c (pk_verify): When fixing R and S, make sure those are copies. -- GnuPG-bug-id: 7426 Fixing-commit: 0a5a854510fda6e6990938a3fca424df868fe676 Signed-off-by: NIIBE Yutaka <gniibe@fsij.org> --- g10/pkglue.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/g10/pkglue.c b/g10/pkglue.c index 9db8f46de..61c504186 100644 --- a/g10/pkglue.c +++ b/g10/pkglue.c @@ -331,6 +331,15 @@ pk_verify (pubkey_algo_t pkalgo, gcry_mpi_t hash, rc = gpg_error (GPG_ERR_BAD_MPI); else { + r = gcry_mpi_copy (r); + s = gcry_mpi_copy (s); + + if (!r || !s) + { + rc = gpg_error_from_syserror (); + goto leave; + } + /* We need to fixup the length in case of leading zeroes. * OpenPGP does not allow leading zeroes and the parser for * the signature packet has no information on the use curve, @@ -416,6 +425,7 @@ pk_verify (pubkey_algo_t pkalgo, gcry_mpi_t hash, if (!rc) rc = gcry_pk_verify (s_sig, s_hash, s_pkey); + leave: gcry_sexp_release (s_sig); gcry_sexp_release (s_hash); gcry_sexp_release (s_pkey);