diff options
| author | Darren Tucker <dtucker@cvs.openbsd.org> | 2022-07-01 03:35:46 +0000 |
|---|---|---|
| committer | Darren Tucker <dtucker@cvs.openbsd.org> | 2022-07-01 03:35:46 +0000 |
| commit | 3ec9706bb9cd149b1c92d7ddea1f493b5103f606 (patch) | |
| tree | f0b221ac3fd2fa8838fa4013ff378aac02efa36a | |
| parent | 034d6b3a7fa9fa9ea3414c2546b534f982702211 (diff) | |
Always return allocated strings from the kex filtering so that we
can free them later. Fix one leak in compat_kex_proposal. Based
on github PR#324 from ZoltanFridrich with some simplications by me.
ok djm@
| -rw-r--r-- | usr.bin/ssh/compat.c | 15 |
1 files changed, 11 insertions, 4 deletions
diff --git a/usr.bin/ssh/compat.c b/usr.bin/ssh/compat.c index 554edb9d80e..babd9411f00 100644 --- a/usr.bin/ssh/compat.c +++ b/usr.bin/ssh/compat.c @@ -1,4 +1,4 @@ -/* $OpenBSD: compat.c,v 1.119 2021/09/10 05:46:09 djm Exp $ */ +/* $OpenBSD: compat.c,v 1.120 2022/07/01 03:35:45 dtucker Exp $ */ /* * Copyright (c) 1999, 2000, 2001, 2002 Markus Friedl. All rights reserved. * @@ -154,11 +154,12 @@ compat_banner(struct ssh *ssh, const char *version) debug_f("no match: %s", version); } +/* Always returns pointer to allocated memory, caller must free. */ char * compat_cipher_proposal(struct ssh *ssh, char *cipher_prop) { if (!(ssh->compat & SSH_BUG_BIGENDIANAES)) - return cipher_prop; + return xstrdup(cipher_prop); debug2_f("original cipher proposal: %s", cipher_prop); if ((cipher_prop = match_filter_denylist(cipher_prop, "aes*")) == NULL) fatal("match_filter_denylist failed"); @@ -168,11 +169,12 @@ compat_cipher_proposal(struct ssh *ssh, char *cipher_prop) return cipher_prop; } +/* Always returns pointer to allocated memory, caller must free. */ char * compat_pkalg_proposal(struct ssh *ssh, char *pkalg_prop) { if (!(ssh->compat & SSH_BUG_RSASIGMD5)) - return pkalg_prop; + return xstrdup(pkalg_prop); debug2_f("original public key proposal: %s", pkalg_prop); if ((pkalg_prop = match_filter_denylist(pkalg_prop, "ssh-rsa")) == NULL) fatal("match_filter_denylist failed"); @@ -182,21 +184,26 @@ compat_pkalg_proposal(struct ssh *ssh, char *pkalg_prop) return pkalg_prop; } +/* Always returns pointer to allocated memory, caller must free. */ char * compat_kex_proposal(struct ssh *ssh, char *p) { + char *cp = NULL; + if ((ssh->compat & (SSH_BUG_CURVE25519PAD|SSH_OLD_DHGEX)) == 0) - return p; + return xstrdup(p); debug2_f("original KEX proposal: %s", p); if ((ssh->compat & SSH_BUG_CURVE25519PAD) != 0) if ((p = match_filter_denylist(p, "curve25519-sha256@libssh.org")) == NULL) fatal("match_filter_denylist failed"); if ((ssh->compat & SSH_OLD_DHGEX) != 0) { + cp = p; if ((p = match_filter_denylist(p, "diffie-hellman-group-exchange-sha256," "diffie-hellman-group-exchange-sha1")) == NULL) fatal("match_filter_denylist failed"); + free(cp); } debug2_f("compat KEX proposal: %s", p); if (*p == '\0') |