From 484d6ba5896acfa3dcf73d9536bcf5e006579b5f Mon Sep 17 00:00:00 2001 From: Werner Koch Date: Mon, 13 May 2019 19:01:28 +0200 Subject: [PATCH] gpg: Change update_keysig_packet to replace SHA-1 by SHA-256. * g10/sign.c (update_keysig_packet): Convert digest algo when needed. -- Several gpg commands try to keep most properties of a key signature when updating (i.e. creating a new version of a key signature). This included the use of the current hash-algorithm. This patch changes this so that SHA-1 or RMD160 are replaced by SHA-256 if possible (i.e. for RSA signatures). Affected commands are for example --quick-set-expire and --quick-set-primary-uid. GnuPG-bug-id: 4508 Signed-off-by: Werner Koch --- g10/sign.c | 11 +++++++++++ 1 file changed, 11 insertions(+) diff --git a/g10/sign.c b/g10/sign.c index 132b94101..d71580639 100644 --- a/g10/sign.c +++ b/g10/sign.c @@ -1714,8 +1714,19 @@ update_keysig_packet (ctrl_t ctrl, || (orig_sig->sig_class == 0x18 && !subpk)) return GPG_ERR_GENERAL; + /* Either use the override digest algo or in the normal case the + * original digest algorithm. However, iff the original digest + * algorithms is SHA-1 and we are in gnupg or de-vs compliance mode + * we switch to SHA-256 (done by the macro). */ if (opt.cert_digest_algo) digest_algo = opt.cert_digest_algo; + else if (pksk->pubkey_algo == PUBKEY_ALGO_DSA + || pksk->pubkey_algo == PUBKEY_ALGO_ECDSA + || pksk->pubkey_algo == PUBKEY_ALGO_EDDSA) + digest_algo = orig_sig->digest_algo; + else if (orig_sig->digest_algo == DIGEST_ALGO_SHA1 + || orig_sig->digest_algo == DIGEST_ALGO_RMD160) + digest_algo = DEFAULT_DIGEST_ALGO; else digest_algo = orig_sig->digest_algo;