From 4aed853f2bbae959ef4b467e643a8580e34a5119 Mon Sep 17 00:00:00 2001 From: Werner Koch Date: Tue, 15 Nov 2022 10:46:03 +0100 Subject: [PATCH] gpgsm: Support verification of nistp521 signatures. * sm/certcheck.c (do_encode_md): Take care of nistp521. -- This curve is a bit odd in that it does not match a common hash digest length. We fix that here for just this case instead of writing more general code to support all allowed cases (i.e. hash shorter than Q). Signed-off-by: Werner Koch Backported-from-master: 596212e71abf33b30608348b782c093dace83110 --- sm/certcheck.c | 13 ++++++++----- 1 file changed, 8 insertions(+), 5 deletions(-) diff --git a/sm/certcheck.c b/sm/certcheck.c index badad2fad..534f47c1b 100644 --- a/sm/certcheck.c +++ b/sm/certcheck.c @@ -76,12 +76,15 @@ do_encode_md (gcry_md_hd_t md, int algo, int pkalgo, unsigned int nbits, if (pkalgo == GCRY_PK_DSA || pkalgo == GCRY_PK_ECC) { - unsigned int qbits; + unsigned int qbits0, qbits; if ( pkalgo == GCRY_PK_ECC ) - qbits = gcry_pk_get_nbits (pkey); + { + qbits0 = gcry_pk_get_nbits (pkey); + qbits = qbits0 == 521? 512 : qbits0; + } else - qbits = get_dsa_qbits (pkey); + qbits0 = qbits = get_dsa_qbits (pkey); if ( (qbits%8) ) { @@ -98,7 +101,7 @@ do_encode_md (gcry_md_hd_t md, int algo, int pkalgo, unsigned int nbits, if (qbits < 160) { log_error (_("%s key uses an unsafe (%u bit) hash\n"), - gcry_pk_algo_name (pkalgo), qbits); + gcry_pk_algo_name (pkalgo), qbits0); return gpg_error (GPG_ERR_INTERNAL); } @@ -109,7 +112,7 @@ do_encode_md (gcry_md_hd_t md, int algo, int pkalgo, unsigned int nbits, { log_error (_("a %u bit hash is not valid for a %u bit %s key\n"), (unsigned int)nframe*8, - gcry_pk_get_nbits (pkey), + qbits0, gcry_pk_algo_name (pkalgo)); /* FIXME: we need to check the requirements for ECDSA. */ if (nframe < 20 || pkalgo == GCRY_PK_DSA )