diff options
| -rw-r--r-- | compat.c | 19 | ||||
| -rw-r--r-- | compat.h | 6 | ||||
| -rw-r--r-- | kex.c | 59 | ||||
| -rw-r--r-- | kex.h | 5 | ||||
| -rw-r--r-- | sshconnect2.c | 65 | ||||
| -rw-r--r-- | sshd.c | 34 |
6 files changed, 102 insertions, 86 deletions
@@ -1,4 +1,4 @@ -/* $OpenBSD: compat.c,v 1.125 2023/02/17 04:22:50 dtucker Exp $ */ +/* $OpenBSD: compat.c,v 1.126 2023/03/06 12:14:48 dtucker Exp $ */ /* * Copyright (c) 1999, 2000, 2001, 2002 Markus Friedl. All rights reserved. * @@ -36,7 +36,6 @@ #include "compat.h" #include "log.h" #include "match.h" -#include "kex.h" /* determine bug flags from SSH protocol banner */ void @@ -140,21 +139,7 @@ compat_banner(struct ssh *ssh, const char *version) /* Always returns pointer to allocated memory, caller must free. */ char * -compat_cipher_proposal(struct ssh *ssh, char *cipher_prop) -{ - return xstrdup(cipher_prop); -} - -/* Always returns pointer to allocated memory, caller must free. */ -char * -compat_pkalg_proposal(struct ssh *ssh, char *pkalg_prop) -{ - return xstrdup(pkalg_prop); -} - -/* Always returns pointer to allocated memory, caller must free. */ -char * -compat_kex_proposal(struct ssh *ssh, char *p) +compat_kex_proposal(struct ssh *ssh, const char *p) { char *cp = NULL, *cp2 = NULL; @@ -1,4 +1,4 @@ -/* $OpenBSD: compat.h,v 1.61 2023/02/17 04:22:50 dtucker Exp $ */ +/* $OpenBSD: compat.h,v 1.62 2023/03/06 12:14:48 dtucker Exp $ */ /* * Copyright (c) 1999, 2000, 2001 Markus Friedl. All rights reserved. @@ -61,7 +61,5 @@ struct ssh; void compat_banner(struct ssh *, const char *); -char *compat_cipher_proposal(struct ssh *, char *); -char *compat_pkalg_proposal(struct ssh *, char *); -char *compat_kex_proposal(struct ssh *, char *); +char *compat_kex_proposal(struct ssh *, const char *); #endif @@ -1,4 +1,4 @@ -/* $OpenBSD: kex.c,v 1.175 2023/02/28 21:31:50 dtucker Exp $ */ +/* $OpenBSD: kex.c,v 1.176 2023/03/06 12:14:48 dtucker Exp $ */ /* * Copyright (c) 2000, 2001 Markus Friedl. All rights reserved. * @@ -57,10 +57,12 @@ #include "misc.h" #include "dispatch.h" #include "monitor.h" +#include "myproposal.h" #include "ssherr.h" #include "sshbuf.h" #include "digest.h" +#include "xmalloc.h" /* prototype */ static int kex_choose_conf(struct ssh *); @@ -317,6 +319,61 @@ kex_assemble_names(char **listp, const char *def, const char *all) return r; } +/* + * Fill out a proposal array with dynamically allocated values, which may + * be modified as required for compatibility reasons. + * Any of the options may be NULL, in which case the default is used. + * Array contents must be freed by calling kex_proposal_free_entries. + */ +void +kex_proposal_populate_entries(struct ssh *ssh, char *prop[PROPOSAL_MAX], + const char *kexalgos, const char *ciphers, const char *macs, + const char *comp, const char *hkalgs) +{ + const char *defpropserver[PROPOSAL_MAX] = { KEX_SERVER }; + const char *defpropclient[PROPOSAL_MAX] = { KEX_CLIENT }; + const char **defprop = ssh->kex->server ? defpropserver : defpropclient; + u_int i; + + if (prop == NULL) + fatal_f("proposal missing"); + + for (i = 0; i < PROPOSAL_MAX; i++) { + switch(i) { + case PROPOSAL_KEX_ALGS: + prop[i] = compat_kex_proposal(ssh, + kexalgos ? kexalgos : defprop[i]); + break; + case PROPOSAL_ENC_ALGS_CTOS: + case PROPOSAL_ENC_ALGS_STOC: + prop[i] = xstrdup(ciphers ? ciphers : defprop[i]); + break; + case PROPOSAL_MAC_ALGS_CTOS: + case PROPOSAL_MAC_ALGS_STOC: + prop[i] = xstrdup(macs ? macs : defprop[i]); + break; + case PROPOSAL_COMP_ALGS_CTOS: + case PROPOSAL_COMP_ALGS_STOC: + prop[i] = xstrdup(comp ? comp : defprop[i]); + break; + case PROPOSAL_SERVER_HOST_KEY_ALGS: + prop[i] = xstrdup(hkalgs ? hkalgs : defprop[i]); + break; + default: + prop[i] = xstrdup(defprop[i]); + } + } +} + +void +kex_proposal_free_entries(char *prop[PROPOSAL_MAX]) +{ + u_int i; + + for (i = 0; i < PROPOSAL_MAX; i++) + free(prop[i]); +} + /* put algorithm proposal into buffer */ int kex_prop2buf(struct sshbuf *b, char *proposal[PROPOSAL_MAX]) @@ -1,4 +1,4 @@ -/* $OpenBSD: kex.h,v 1.117 2022/01/06 21:55:23 djm Exp $ */ +/* $OpenBSD: kex.h,v 1.118 2023/03/06 12:14:48 dtucker Exp $ */ /* * Copyright (c) 2000, 2001 Markus Friedl. All rights reserved. @@ -182,6 +182,9 @@ int kex_names_valid(const char *); char *kex_alg_list(char); char *kex_names_cat(const char *, const char *); int kex_assemble_names(char **, const char *, const char *); +void kex_proposal_populate_entries(struct ssh *, char *prop[PROPOSAL_MAX], + const char *, const char *, const char *, const char *, const char *); +void kex_proposal_free_entries(char *prop[PROPOSAL_MAX]); int kex_exchange_identification(struct ssh *, int, const char *); diff --git a/sshconnect2.c b/sshconnect2.c index 5b232e1b..03d00d33 100644 --- a/sshconnect2.c +++ b/sshconnect2.c @@ -1,4 +1,4 @@ -/* $OpenBSD: sshconnect2.c,v 1.363 2023/03/03 02:34:29 dtucker Exp $ */ +/* $OpenBSD: sshconnect2.c,v 1.364 2023/03/06 12:14:48 dtucker Exp $ */ /* * Copyright (c) 2000 Markus Friedl. All rights reserved. * Copyright (c) 2008 Damien Miller. All rights reserved. @@ -56,7 +56,6 @@ #include "cipher.h" #include "sshkey.h" #include "kex.h" -#include "myproposal.h" #include "sshconnect.h" #include "authfile.h" #include "dh.h" @@ -221,24 +220,17 @@ void ssh_kex2(struct ssh *ssh, char *host, struct sockaddr *hostaddr, u_short port, const struct ssh_conn_info *cinfo) { - char *myproposal[PROPOSAL_MAX] = { KEX_CLIENT }; - char *s, *all_key; - char *prop_kex = NULL, *prop_enc = NULL, *prop_hostkey = NULL; - int r, use_known_hosts_order = 0; + char *myproposal[PROPOSAL_MAX]; + char *s, *all_key, *hkalgs = NULL; + int r; xxx_host = host; xxx_hostaddr = hostaddr; xxx_conn_info = cinfo; - /* - * If the user has not specified HostkeyAlgorithms, or has only - * appended or removed algorithms from that list then prefer algorithms - * that are in the list that are supported by known_hosts keys. - */ - if (options.hostkeyalgorithms == NULL || - options.hostkeyalgorithms[0] == '-' || - options.hostkeyalgorithms[0] == '+') - use_known_hosts_order = 1; + if (options.rekey_limit || options.rekey_interval) + ssh_packet_set_rekey_limits(ssh, options.rekey_limit, + options.rekey_interval); /* Expand or fill in HostkeyAlgorithms */ all_key = sshkey_alg_list(0, 0, 1, ','); @@ -249,29 +241,22 @@ ssh_kex2(struct ssh *ssh, char *host, struct sockaddr *hostaddr, u_short port, if ((s = kex_names_cat(options.kex_algorithms, "ext-info-c")) == NULL) fatal_f("kex_names_cat"); - myproposal[PROPOSAL_KEX_ALGS] = prop_kex = compat_kex_proposal(ssh, s); - myproposal[PROPOSAL_ENC_ALGS_CTOS] = - myproposal[PROPOSAL_ENC_ALGS_STOC] = prop_enc = - compat_cipher_proposal(ssh, options.ciphers); - myproposal[PROPOSAL_COMP_ALGS_CTOS] = - myproposal[PROPOSAL_COMP_ALGS_STOC] = - (char *)compression_alg_list(options.compression); - myproposal[PROPOSAL_MAC_ALGS_CTOS] = - myproposal[PROPOSAL_MAC_ALGS_STOC] = options.macs; - if (use_known_hosts_order) { - /* Query known_hosts and prefer algorithms that appear there */ - myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS] = prop_hostkey = - compat_pkalg_proposal(ssh, - order_hostkeyalgs(host, hostaddr, port, cinfo)); - } else { - /* Use specified HostkeyAlgorithms exactly */ - myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS] = prop_hostkey = - compat_pkalg_proposal(ssh, options.hostkeyalgorithms); - } - if (options.rekey_limit || options.rekey_interval) - ssh_packet_set_rekey_limits(ssh, options.rekey_limit, - options.rekey_interval); + /* + * If the user has not specified HostkeyAlgorithms, or has only + * appended or removed algorithms from that list then prefer algorithms + * that are in the list that are supported by known_hosts keys. + */ + if (options.hostkeyalgorithms == NULL || + options.hostkeyalgorithms[0] == '-' || + options.hostkeyalgorithms[0] == '+') + hkalgs = order_hostkeyalgs(host, hostaddr, port, cinfo); + + kex_proposal_populate_entries(ssh, myproposal, s, options.ciphers, + options.macs, compression_alg_list(options.compression), + hkalgs ? hkalgs : options.hostkeyalgorithms); + + free(hkalgs); /* start key exchange */ if ((r = kex_setup(ssh, myproposal)) != 0) @@ -295,6 +280,7 @@ ssh_kex2(struct ssh *ssh, char *host, struct sockaddr *hostaddr, u_short port, ssh_dispatch_run_fatal(ssh, DISPATCH_BLOCK, &ssh->kex->done); /* remove ext-info from the KEX proposals for rekeying */ + free(myproposal[PROPOSAL_KEX_ALGS]); myproposal[PROPOSAL_KEX_ALGS] = compat_kex_proposal(ssh, options.kex_algorithms); if ((r = kex_prop2buf(ssh->kex->my, myproposal)) != 0) @@ -308,10 +294,7 @@ ssh_kex2(struct ssh *ssh, char *host, struct sockaddr *hostaddr, u_short port, (r = ssh_packet_write_wait(ssh)) != 0) fatal_fr(r, "send packet"); #endif - /* Free only parts of proposal that were dynamically allocated here. */ - free(prop_kex); - free(prop_enc); - free(prop_hostkey); + kex_proposal_free_entries(myproposal); } /* @@ -1,4 +1,4 @@ -/* $OpenBSD: sshd.c,v 1.598 2023/03/03 03:12:24 dtucker Exp $ */ +/* $OpenBSD: sshd.c,v 1.599 2023/03/06 12:14:48 dtucker Exp $ */ /* * Author: Tatu Ylonen <ylo@cs.hut.fi> * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland @@ -104,7 +104,6 @@ #include "digest.h" #include "sshkey.h" #include "kex.h" -#include "myproposal.h" #include "authfile.h" #include "pathnames.h" #include "atomicio.h" @@ -2389,30 +2388,23 @@ sshd_hostkey_sign(struct ssh *ssh, struct sshkey *privkey, static void do_ssh2_kex(struct ssh *ssh) { - char *myproposal[PROPOSAL_MAX] = { KEX_SERVER }; + char *hkalgs = NULL, *myproposal[PROPOSAL_MAX]; + const char *compression = NULL; struct kex *kex; - char *prop_kex = NULL, *prop_enc = NULL, *prop_hostkey = NULL; int r; - myproposal[PROPOSAL_KEX_ALGS] = prop_kex = compat_kex_proposal(ssh, - options.kex_algorithms); - myproposal[PROPOSAL_ENC_ALGS_CTOS] = - myproposal[PROPOSAL_ENC_ALGS_STOC] = prop_enc = - compat_cipher_proposal(ssh, options.ciphers); - myproposal[PROPOSAL_MAC_ALGS_CTOS] = - myproposal[PROPOSAL_MAC_ALGS_STOC] = options.macs; - - if (options.compression == COMP_NONE) { - myproposal[PROPOSAL_COMP_ALGS_CTOS] = - myproposal[PROPOSAL_COMP_ALGS_STOC] = "none"; - } - if (options.rekey_limit || options.rekey_interval) ssh_packet_set_rekey_limits(ssh, options.rekey_limit, options.rekey_interval); - myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS] = prop_hostkey = - compat_pkalg_proposal(ssh, list_hostkey_types()); + if (options.compression == COMP_NONE) + compression = "none"; + hkalgs = list_hostkey_types(); + + kex_proposal_populate_entries(ssh, myproposal, options.kex_algorithms, + options.ciphers, options.macs, compression, hkalgs); + + free(hkalgs); /* start key exchange */ if ((r = kex_setup(ssh, myproposal)) != 0) @@ -2447,9 +2439,7 @@ do_ssh2_kex(struct ssh *ssh) (r = ssh_packet_write_wait(ssh)) != 0) fatal_fr(r, "send test"); #endif - free(prop_kex); - free(prop_enc); - free(prop_hostkey); + kex_proposal_free_entries(myproposal); debug("KEX done"); } |