From 9aab9167bca38323973e853845ca95ae8e9b6871 Mon Sep 17 00:00:00 2001 From: Werner Koch Date: Tue, 23 Jan 2018 12:07:25 +0100 Subject: gpg: Implement AEAD for SKESK packets. * g10/packet.h (PKT_symkey_enc): Add field aead_algo. * g10/build-packet.c (do_symkey_enc): Support version 5 packets. * g10/parse-packet.c (parse_symkeyenc): Ditto. * g10/encrypt.c (encrypt_symmetric): Force using a random session key in AEAD mode. (encrypt_seskey): Add and support arg aead_algo. (write_symkey_enc): Ditto. (encrypt_simple): Adjust accordingly. (encrypt_filter): Ditto. * g10/gpgcompose.c (sk_esk): For now call encrypt_seskey without AEAD support. * g10/mainproc.c (symkey_decrypt_seskey): Support AEAD. Nver call BUG but return an error. (proc_symkey_enc): Call symkey_decrypt_seskey in a bug compatible way. * g10/import.c (check_prefs): Check AEAD preferences. * g10/keyedit.c (show_prefs): Print AEAD preferences. -- For easier debugging this patch also changes some diagnostics to also print the encryption mode with the cipher algorithm. Signed-off-by: Werner Koch --- g10/parse-packet.c | 32 +++++++++++++++++++++++++++----- 1 file changed, 27 insertions(+), 5 deletions(-) (limited to 'g10/parse-packet.c') diff --git a/g10/parse-packet.c b/g10/parse-packet.c index de51770af..5c6d364ee 100644 --- a/g10/parse-packet.c +++ b/g10/parse-packet.c @@ -1105,7 +1105,7 @@ parse_symkeyenc (IOBUF inp, int pkttype, unsigned long pktlen, { PKT_symkey_enc *k; int rc = 0; - int i, version, s2kmode, cipher_algo, hash_algo, seskeylen, minlen; + int i, version, s2kmode, cipher_algo, aead_algo, hash_algo, seskeylen, minlen; if (pktlen < 4) { @@ -1117,7 +1117,11 @@ parse_symkeyenc (IOBUF inp, int pkttype, unsigned long pktlen, } version = iobuf_get_noeof (inp); pktlen--; - if (version != 4) + if (version == 4) + ; + else if (version == 5) + ; + else { log_error ("packet(%d) with unknown version %d\n", pkttype, version); if (list_mode) @@ -1135,6 +1139,13 @@ parse_symkeyenc (IOBUF inp, int pkttype, unsigned long pktlen, } cipher_algo = iobuf_get_noeof (inp); pktlen--; + if (version == 5) + { + aead_algo = iobuf_get_noeof (inp); + pktlen--; + } + else + aead_algo = 0; s2kmode = iobuf_get_noeof (inp); pktlen--; hash_algo = iobuf_get_noeof (inp); @@ -1169,6 +1180,7 @@ parse_symkeyenc (IOBUF inp, int pkttype, unsigned long pktlen, + seskeylen - 1); k->version = version; k->cipher_algo = cipher_algo; + k->aead_algo = aead_algo; k->s2k.mode = s2kmode; k->s2k.hash_algo = hash_algo; if (s2kmode == 1 || s2kmode == 3) @@ -1199,10 +1211,20 @@ parse_symkeyenc (IOBUF inp, int pkttype, unsigned long pktlen, if (list_mode) { es_fprintf (listfp, - ":symkey enc packet: version %d, cipher %d, s2k %d, hash %d", - version, cipher_algo, s2kmode, hash_algo); + ":symkey enc packet: version %d, cipher %d, aead %d," + " s2k %d, hash %d", + version, cipher_algo, aead_algo, s2kmode, hash_algo); if (seskeylen) - es_fprintf (listfp, ", seskey %d bits", (seskeylen - 1) * 8); + { + /* To compute the size of the session key we need to know + * the size of the AEAD nonce which we may not know. Thus + * we show only the seize of the entire encrypted session + * key. */ + if (aead_algo) + es_fprintf (listfp, ", encrypted seskey %d bytes", seskeylen); + else + es_fprintf (listfp, ", seskey %d bits", (seskeylen - 1) * 8); + } es_fprintf (listfp, "\n"); if (s2kmode == 1 || s2kmode == 3) { -- cgit v1.2.3