import CS openssh-8.0p1-24.el8

This commit is contained in:
eabdullin 2024-03-27 20:09:54 +00:00
parent 9dbd8185cd
commit 29a5db689e
11 changed files with 809 additions and 42 deletions

View File

@ -136,18 +136,6 @@ diff -up openssh-7.4p1/serverloop.c.coverity openssh-7.4p1/serverloop.c
if (tun != SSH_TUNID_ANY &&
auth_opts->force_tun_device != (int)tun)
goto done;
diff -up openssh-7.4p1/sftp.c.coverity openssh-7.4p1/sftp.c
--- openssh-7.4p1/sftp.c.coverity 2016-12-19 05:59:41.000000000 +0100
+++ openssh-7.4p1/sftp.c 2016-12-23 16:40:26.903788691 +0100
@@ -224,7 +224,7 @@ killchild(int signo)
{
if (sshpid > 1) {
kill(sshpid, SIGTERM);
- waitpid(sshpid, NULL, 0);
+ (void) waitpid(sshpid, NULL, 0);
}
_exit(1);
diff -up openssh-7.4p1/ssh-agent.c.coverity openssh-7.4p1/ssh-agent.c
--- openssh-7.4p1/ssh-agent.c.coverity 2016-12-19 05:59:41.000000000 +0100
+++ openssh-7.4p1/ssh-agent.c 2016-12-23 16:40:26.903788691 +0100

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@ -471,12 +471,53 @@ diff -up openssh-7.9p1/sshkey.c.fips openssh-7.9p1/sshkey.c
#include "xmss_fast.h"
@@ -392,7 +394,8 @@ sshkey_calculate_signature(EVP_PKEY *pkey
{
EVP_MD_CTX *ctx = NULL;
u_char *sig = NULL;
- int ret, slen, len;
+ int ret, slen;
+ size_t len;
if (sigp == NULL || lenp == NULL) {
return SSH_ERR_INVALID_ARGUMENT;
@@ -411,9 +414,10 @@ sshkey_calculate_signature(EVP_PKEY *pkey
ret = SSH_ERR_ALLOC_FAIL;
goto error;
}
- if (EVP_SignInit_ex(ctx, ssh_digest_to_md(hash_alg), NULL) <= 0 ||
- EVP_SignUpdate(ctx, data, datalen) <= 0 ||
- EVP_SignFinal(ctx, sig, &len, pkey) <= 0) {
+ if (EVP_DigestSignInit(ctx, NULL, ssh_digest_to_md(hash_alg),
+ NULL, pkey) != 1 ||
+ EVP_DigestSignUpdate(ctx, data, datalen) != 1 ||
+ EVP_DigestSignFinal(ctx, sig, &len) != 1) {
ret = SSH_ERR_LIBCRYPTO_ERROR;
goto error;
}
@@ -440,12 +444,13 @@ sshkey_verify_signature(EVP_PKEY *pkey
if ((ctx = EVP_MD_CTX_new()) == NULL) {
return SSH_ERR_ALLOC_FAIL;
}
- if (EVP_VerifyInit_ex(ctx, ssh_digest_to_md(hash_alg), NULL) <= 0 ||
- EVP_VerifyUpdate(ctx, data, datalen) <= 0) {
+ if (EVP_DigestVerifyInit(ctx, NULL, ssh_digest_to_md(hash_alg),
+ NULL, pkey) != 1 ||
+ EVP_DigestVerifyUpdate(ctx, data, datalen) != 1) {
ret = SSH_ERR_LIBCRYPTO_ERROR;
goto done;
}
- ret = EVP_VerifyFinal(ctx, sigbuf, siglen, pkey);
+ ret = EVP_DigestVerifyFinal(ctx, sigbuf, siglen);
switch (ret) {
case 1:
ret = 0;
@@ -1514,6 +1516,8 @@ rsa_generate_private_key(u_int bits, RSA
}
if (!BN_set_word(f4, RSA_F4) ||
!RSA_generate_key_ex(private, bits, f4, NULL)) {
+ if (FIPS_mode())
+ logit("%s: the key length might be unsupported by FIPS mode approved key generation method", __func__);
+ if (FIPS_mode())
+ logit("%s: the key length might be unsupported by FIPS mode approved key generation method", __func__);
ret = SSH_ERR_LIBCRYPTO_ERROR;
goto out;
}
@ -515,3 +556,14 @@ diff -up openssh-7.9p1/ssh-keygen.c.fips openssh-7.9p1/ssh-keygen.c
if ((fd = mkstemp(prv_tmp)) == -1) {
error("Could not save your public key in %s: %s",
prv_tmp, strerror(errno));
diff -up openssh-8.0p1/sshd_config.xxx openssh-8.0p1/sshd_config
--- openssh-8.0p1/sshd_config.xxx 2023-10-30 13:01:59.150952364 +0100
+++ openssh-8.0p1/sshd_config 2023-10-30 13:02:56.662231354 +0100
@@ -21,6 +21,7 @@
HostKey /etc/ssh/ssh_host_rsa_key
HostKey /etc/ssh/ssh_host_ecdsa_key
+#In FIPS mode Ed25519 keys are not supported, please comment out the next line
HostKey /etc/ssh/ssh_host_ed25519_key
# Ciphers and keying

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@ -0,0 +1,20 @@
diff --git a/sftp.c b/sftp.c
index b66037f1..54538ff9 100644
--- a/sftp.c
+++ b/sftp.c
@@ -220,9 +220,12 @@ static const struct CMD cmds[] = {
static void
killchild(int signo)
{
- if (sshpid > 1) {
- kill(sshpid, SIGTERM);
- waitpid(sshpid, NULL, 0);
+ pid_t pid;
+
+ pid = sshpid;
+ if (pid > 1) {
+ kill(pid, SIGTERM);
+ (void)waitpid(pid, NULL, 0);
}
_exit(1);

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@ -0,0 +1,13 @@
diff --git a/msg.c b/msg.c
index 99c25cd2..574a566e 100644
--- a/msg.c
+++ b/msg.c
@@ -77,7 +77,7 @@ ssh_msg_recv(int fd, struct sshbuf *m)
return (-1);
}
msg_len = get_u32(buf);
- if (msg_len > 256 * 1024) {
+ if (msg_len > sshbuf_max_size(m)) {
error("ssh_msg_recv: read: bad msg_len %u", msg_len);
return (-1);
}

View File

@ -1509,7 +1509,7 @@ new file mode 100644
index 00000000..0b2f6a56
--- /dev/null
+++ b/kexgssc.c
@@ -0,0 +1,595 @@
@@ -0,0 +1,618 @@
+/*
+ * Copyright (c) 2001-2009 Simon Wilkinson. All rights reserved.
+ *
@ -1571,7 +1571,7 @@ index 00000000..0b2f6a56
+ struct sshbuf *server_blob = NULL;
+ struct sshbuf *shared_secret = NULL;
+ struct sshbuf *server_host_key_blob = NULL;
+ struct sshbuf *empty = sshbuf_new();
+ struct sshbuf *empty = NULL;
+ u_char *msg;
+ int type = 0;
+ int first = 1;
@ -1610,8 +1610,10 @@ index 00000000..0b2f6a56
+ default:
+ fatal("%s: Unexpected KEX type %d", __func__, kex->kex_type);
+ }
+ if (r != 0)
+ if (r != 0) {
+ ssh_gssapi_delete_ctx(&ctxt);
+ return r;
+ }
+
+ token_ptr = GSS_C_NO_BUFFER;
+
@ -1674,11 +1676,16 @@ index 00000000..0b2f6a56
+ do {
+ type = ssh_packet_read(ssh);
+ if (type == SSH2_MSG_KEXGSS_HOSTKEY) {
+ char *tmp = NULL;
+ size_t tmp_len = 0;
+
+ debug("Received KEXGSS_HOSTKEY");
+ if (server_host_key_blob)
+ fatal("Server host key received more than once");
+ if ((r = sshpkt_getb_froms(ssh, &server_host_key_blob)) != 0)
+ if ((r = sshpkt_get_string(ssh, &tmp, &tmp_len)) != 0)
+ fatal("Failed to read server host key: %s", ssh_err(r));
+ if ((server_host_key_blob = sshbuf_from(tmp, tmp_len)) == NULL)
+ fatal("sshbuf_from failed");
+ }
+ } while (type == SSH2_MSG_KEXGSS_HOSTKEY);
+
@ -1779,6 +1786,11 @@ index 00000000..0b2f6a56
+ if (r != 0)
+ goto out;
+
+ if ((empty = sshbuf_new()) == NULL) {
+ r = SSH_ERR_ALLOC_FAIL;
+ goto out;
+ }
+
+ hashlen = sizeof(hash);
+ if ((r = kex_gen_hash(
+ kex->hash_alg,
@ -1848,7 +1860,7 @@ index 00000000..0b2f6a56
+ size_t hashlen;
+ const BIGNUM *pub_key, *dh_p, *dh_g;
+ int nbits = 0, min = DH_GRP_MIN, max = DH_GRP_MAX;
+ struct sshbuf *empty = sshbuf_new();
+ struct sshbuf *empty = NULL;
+ u_char c;
+ int r;
+
@ -1960,11 +1972,16 @@ index 00000000..0b2f6a56
+ do {
+ type = ssh_packet_read(ssh);
+ if (type == SSH2_MSG_KEXGSS_HOSTKEY) {
+ char *tmp = NULL;
+ size_t tmp_len = 0;
+
+ debug("Received KEXGSS_HOSTKEY");
+ if (server_host_key_blob)
+ fatal("Server host key received more than once");
+ if ((r = sshpkt_getb_froms(ssh, &server_host_key_blob)) != 0)
+ if ((r = sshpkt_get_string(ssh, &tmp, &tmp_len)) != 0)
+ fatal("sshpkt failed: %s", ssh_err(r));
+ if ((server_host_key_blob = sshbuf_from(tmp, tmp_len)) == NULL)
+ fatal("sshbuf_from failed");
+ }
+ } while (type == SSH2_MSG_KEXGSS_HOSTKEY);
+
@ -2040,6 +2057,7 @@ index 00000000..0b2f6a56
+ (r = sshbuf_get_bignum2(buf, &dh_server_pub)) != 0)
+ goto out;
+ sshbuf_free(buf);
+ buf = NULL;
+
+ if ((shared_secret = sshbuf_new()) == NULL) {
+ r = SSH_ERR_ALLOC_FAIL;
@ -2048,6 +2066,10 @@ index 00000000..0b2f6a56
+
+ if ((r = kex_dh_compute_key(kex, dh_server_pub, shared_secret)) != 0)
+ goto out;
+ if ((empty = sshbuf_new()) == NULL) {
+ r = SSH_ERR_ALLOC_FAIL;
+ goto out;
+ }
+
+ DH_get0_pqg(kex->dh, &dh_p, NULL, &dh_g);
+ hashlen = sizeof(hash);
@ -2094,6 +2116,7 @@ index 00000000..0b2f6a56
+ if ((r = kex_derive_keys(ssh, hash, hashlen, shared_secret)) == 0)
+ r = kex_send_newkeys(ssh);
+out:
+ sshbuf_free(buf);
+ sshbuf_free(server_blob);
+ sshbuf_free(empty);
+ explicit_bzero(hash, sizeof(hash));
@ -2110,7 +2133,7 @@ new file mode 100644
index 00000000..60bc02de
--- /dev/null
+++ b/kexgsss.c
@@ -0,0 +1,474 @@
@@ -0,0 +1,482 @@
+/*
+ * Copyright (c) 2001-2009 Simon Wilkinson. All rights reserved.
+ *
@ -2177,7 +2200,7 @@ index 00000000..60bc02de
+ */
+
+ OM_uint32 ret_flags = 0;
+ gss_buffer_desc gssbuf, recv_tok, msg_tok;
+ gss_buffer_desc gssbuf = {0, NULL}, recv_tok, msg_tok;
+ gss_buffer_desc send_tok = GSS_C_EMPTY_BUFFER;
+ Gssctxt *ctxt = NULL;
+ struct sshbuf *shared_secret = NULL;
@ -2217,7 +2240,7 @@ index 00000000..60bc02de
+ type = ssh_packet_read(ssh);
+ switch(type) {
+ case SSH2_MSG_KEXGSS_INIT:
+ if (client_pubkey != NULL)
+ if (gssbuf.value != NULL)
+ fatal("Received KEXGSS_INIT after initialising");
+ if ((r = ssh_gssapi_sshpkt_get_buffer_desc(ssh,
+ &recv_tok)) != 0 ||
@ -2248,6 +2271,31 @@ index 00000000..60bc02de
+ goto out;
+
+ /* Send SSH_MSG_KEXGSS_HOSTKEY here, if we want */
+
+ /* Calculate the hash early so we can free the
+ * client_pubkey, which has reference to the parent
+ * buffer state->incoming_packet
+ */
+ hashlen = sizeof(hash);
+ if ((r = kex_gen_hash(
+ kex->hash_alg,
+ kex->client_version,
+ kex->server_version,
+ kex->peer,
+ kex->my,
+ empty,
+ client_pubkey,
+ server_pubkey,
+ shared_secret,
+ hash, &hashlen)) != 0)
+ goto out;
+
+ gssbuf.value = hash;
+ gssbuf.length = hashlen;
+
+ sshbuf_free(client_pubkey);
+ client_pubkey = NULL;
+
+ break;
+ case SSH2_MSG_KEXGSS_CONTINUE:
+ if ((r = ssh_gssapi_sshpkt_get_buffer_desc(ssh,
@ -2269,7 +2317,7 @@ index 00000000..60bc02de
+ if (maj_status != GSS_S_COMPLETE && send_tok.length == 0)
+ fatal("Zero length token output when incomplete");
+
+ if (client_pubkey == NULL)
+ if (gssbuf.value == NULL)
+ fatal("No client public key");
+
+ if (maj_status & GSS_S_CONTINUE_NEEDED) {
@ -2298,23 +2346,6 @@ index 00000000..60bc02de
+ if (!(ret_flags & GSS_C_INTEG_FLAG))
+ fatal("Integrity flag wasn't set");
+
+ hashlen = sizeof(hash);
+ if ((r = kex_gen_hash(
+ kex->hash_alg,
+ kex->client_version,
+ kex->server_version,
+ kex->peer,
+ kex->my,
+ empty,
+ client_pubkey,
+ server_pubkey,
+ shared_secret,
+ hash, &hashlen)) != 0)
+ goto out;
+
+ gssbuf.value = hash;
+ gssbuf.length = hashlen;
+
+ if (GSS_ERROR(PRIVSEP(ssh_gssapi_sign(ctxt, &gssbuf, &msg_tok))))
+ fatal("Couldn't get MIC");
+

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@ -0,0 +1,46 @@
diff -up openssh-8.7p1/pathnames.h.kill-scp openssh-8.7p1/pathnames.h
--- openssh-8.7p1/pathnames.h.kill-scp 2021-09-16 11:37:57.240171687 +0200
+++ openssh-8.7p1/pathnames.h 2021-09-16 11:42:29.183427917 +0200
@@ -42,6 +42,7 @@
#define _PATH_HOST_XMSS_KEY_FILE SSHDIR "/ssh_host_xmss_key"
#define _PATH_HOST_RSA_KEY_FILE SSHDIR "/ssh_host_rsa_key"
#define _PATH_DH_MODULI SSHDIR "/moduli"
+#define _PATH_SCP_KILL_SWITCH SSHDIR "/disable_scp"
#ifndef _PATH_SSH_PROGRAM
#define _PATH_SSH_PROGRAM "/usr/bin/ssh"
diff -up openssh-8.7p1/scp.1.kill-scp openssh-8.7p1/scp.1
--- openssh-8.7p1/scp.1.kill-scp 2021-09-16 12:09:02.646714578 +0200
+++ openssh-8.7p1/scp.1 2021-09-16 12:26:49.978628226 +0200
@@ -278,6 +278,13 @@ to print debugging messages about their
This is helpful in
debugging connection, authentication, and configuration problems.
.El
+.Pp
+Usage of SCP protocol can be blocked by creating a world-readable
+.Ar /etc/ssh/disable_scp
+file. If this file exists, when SCP protocol is in use (either remotely or
+via the
+.Fl O
+option), the program will exit.
.Sh EXIT STATUS
.Ex -std scp
.Sh SEE ALSO
diff -up openssh-8.7p1/scp.c.kill-scp openssh-8.7p1/scp.c
--- openssh-8.7p1/scp.c.kill-scp 2021-09-16 11:42:56.013650519 +0200
+++ openssh-8.7p1/scp.c 2021-09-16 11:53:03.249713836 +0200
@@ -596,6 +596,14 @@ main(int argc, char **argv)
argc -= optind;
argv += optind;
+ {
+ FILE *f = fopen(_PATH_SCP_KILL_SWITCH, "r");
+ if (f != NULL) {
+ fclose(f);
+ fatal("SCP protocol is forbidden via %s", _PATH_SCP_KILL_SWITCH);
+ }
+ }
+
if ((pwd = getpwuid(userid = getuid())) == NULL)
fatal("unknown user %u", (u_int) userid);

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@ -0,0 +1,17 @@
diff --git a/ssh-pkcs11.c b/ssh-pkcs11.c
index 6be647ec..ebddf6c3 100644
--- a/ssh-pkcs11.c
+++ b/ssh-pkcs11.c
@@ -1537,10 +1537,8 @@ pkcs11_register_provider(char *provider_id, char *pin,
error("dlopen %s failed: %s", provider_module, dlerror());
goto fail;
}
- if ((getfunctionlist = dlsym(handle, "C_GetFunctionList")) == NULL) {
- error("dlsym(C_GetFunctionList) failed: %s", dlerror());
- goto fail;
- }
+ if ((getfunctionlist = dlsym(handle, "C_GetFunctionList")) == NULL)
+ fatal("dlsym(C_GetFunctionList) failed: %s", dlerror());
p->module->handle = handle;
/* setup the pkcs11 callbacks */

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@ -0,0 +1,33 @@
diff -u -p -r1.166 auth2.c
--- a/auth2.c 8 Mar 2023 04:43:12 -0000 1.166
+++ b/auth2.c 28 Aug 2023 08:32:44 -0000
@@ -208,6 +208,7 @@ input_service_request(int type, u_int32_
}
#define MIN_FAIL_DELAY_SECONDS 0.005
+#define MAX_FAIL_DELAY_SECONDS 5.0
static double
user_specific_delay(const char *user)
{
@@ -233,6 +234,12 @@ ensure_minimum_time_since(double start,
struct timespec ts;
double elapsed = monotime_double() - start, req = seconds, remain;
+ if (elapsed > MAX_FAIL_DELAY_SECONDS) {
+ debug3("elapsed %0.3lfms exceeded the max delay "
+ "requested %0.3lfms)", elapsed*1000, req*1000);
+ return;
+ }
+
/* if we've already passed the requested time, scale up */
while ((remain = seconds - elapsed) < 0.0)
seconds *= 2;
@@ -317,7 +324,7 @@ input_userauth_request(int type, u_int32
debug2("input_userauth_request: try method %s", method);
authenticated = m->userauth(ssh);
}
- if (!authctxt->authenticated)
+ if (!authctxt->authenticated && strcmp(method, "none") != 0)
ensure_minimum_time_since(tstart,
user_specific_delay(authctxt->user));
userauth_finish(ssh, authenticated, method, NULL);

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@ -0,0 +1,447 @@
diff --git a/PROTOCOL b/PROTOCOL
index d453c779..ded935eb 100644
--- a/PROTOCOL
+++ b/PROTOCOL
@@ -137,6 +137,32 @@ than as a named global or channel request to allow pings with very
described at:
http://git.libssh.org/users/aris/libssh.git/plain/doc/curve25519-sha256@libssh.org.txt?h=curve25519
+1.9 transport: strict key exchange extension
+
+OpenSSH supports a number of transport-layer hardening measures under
+a "strict KEX" feature. This feature is signalled similarly to the
+RFC8308 ext-info feature: by including a additional algorithm in the
+initiial SSH2_MSG_KEXINIT kex_algorithms field. The client may append
+"kex-strict-c-v00@openssh.com" to its kex_algorithms and the server
+may append "kex-strict-s-v00@openssh.com". These pseudo-algorithms
+are only valid in the initial SSH2_MSG_KEXINIT and MUST be ignored
+if they are present in subsequent SSH2_MSG_KEXINIT packets.
+
+When an endpoint that supports this extension observes this algorithm
+name in a peer's KEXINIT packet, it MUST make the following changes to
+the the protocol:
+
+a) During initial KEX, terminate the connection if any unexpected or
+ out-of-sequence packet is received. This includes terminating the
+ connection if the first packet received is not SSH2_MSG_KEXINIT.
+ Unexpected packets for the purpose of strict KEX include messages
+ that are otherwise valid at any time during the connection such as
+ SSH2_MSG_DEBUG and SSH2_MSG_IGNORE.
+b) After sending or receiving a SSH2_MSG_NEWKEYS message, reset the
+ packet sequence number to zero. This behaviour persists for the
+ duration of the connection (i.e. not just the first
+ SSH2_MSG_NEWKEYS).
+
2. Connection protocol changes
2.1. connection: Channel write close extension "eow@openssh.com"
diff --git a/kex.c b/kex.c
index aa5e792d..d478ff6e 100644
--- a/kex.c
+++ b/kex.c
@@ -65,7 +65,7 @@
#endif
/* prototype */
-static int kex_choose_conf(struct ssh *);
+static int kex_choose_conf(struct ssh *, uint32_t seq);
static int kex_input_newkeys(int, u_int32_t, struct ssh *);
static const char *proposal_names[PROPOSAL_MAX] = {
@@ -177,6 +177,18 @@ kex_names_valid(const char *names)
return 1;
}
+/* returns non-zero if proposal contains any algorithm from algs */
+static int
+has_any_alg(const char *proposal, const char *algs)
+{
+ char *cp;
+
+ if ((cp = match_list(proposal, algs, NULL)) == NULL)
+ return 0;
+ free(cp);
+ return 1;
+}
+
/*
* Concatenate algorithm names, avoiding duplicates in the process.
* Caller must free returned string.
@@ -184,7 +196,7 @@ kex_names_valid(const char *names)
char *
kex_names_cat(const char *a, const char *b)
{
- char *ret = NULL, *tmp = NULL, *cp, *p, *m;
+ char *ret = NULL, *tmp = NULL, *cp, *p;
size_t len;
if (a == NULL || *a == '\0')
@@ -201,10 +213,8 @@ kex_names_cat(const char *a, const char *b)
}
strlcpy(ret, a, len);
for ((p = strsep(&cp, ",")); p && *p != '\0'; (p = strsep(&cp, ","))) {
- if ((m = match_list(ret, p, NULL)) != NULL) {
- free(m);
+ if (has_any_alg(ret, p))
continue; /* Algorithm already present */
- }
if (strlcat(ret, ",", len) >= len ||
strlcat(ret, p, len) >= len) {
free(tmp);
@@ -466,7 +485,12 @@ kex_protocol_error(int type, u_int32_t seq, struct ssh *ssh)
{
int r;
- error("kex protocol error: type %d seq %u", type, seq);
+ /* If in strict mode, any unexpected message is an error */
+ if ((ssh->kex->flags & KEX_INITIAL) && ssh->kex->kex_strict) {
+ ssh_packet_disconnect(ssh, "strict KEX violation: "
+ "unexpected packet type %u (seqnr %u)", type, seq);
+ }
+ error("type %u seq %u", type, seq);
if ((r = sshpkt_start(ssh, SSH2_MSG_UNIMPLEMENTED)) != 0 ||
(r = sshpkt_put_u32(ssh, seq)) != 0 ||
(r = sshpkt_send(ssh)) != 0)
@@ -548,6 +572,11 @@ kex_input_ext_info(int type, u_int32_t seq, struct ssh *ssh)
ssh_dispatch_set(ssh, SSH2_MSG_EXT_INFO, &kex_protocol_error);
if ((r = sshpkt_get_u32(ssh, &ninfo)) != 0)
return r;
+ if (ninfo >= 1024) {
+ error("SSH2_MSG_EXT_INFO with too many entries, expected "
+ "<=1024, received %u", ninfo);
+ return dispatch_protocol_error(type, seq, ssh);
+ }
for (i = 0; i < ninfo; i++) {
if ((r = sshpkt_get_cstring(ssh, &name, NULL)) != 0)
return r;
@@ -681,7 +705,7 @@ kex_input_kexinit(int type, u_int32_t seq, struct ssh *ssh)
if (kex == NULL)
return SSH_ERR_INVALID_ARGUMENT;
- ssh_dispatch_set(ssh, SSH2_MSG_KEXINIT, NULL);
+ ssh_dispatch_set(ssh, SSH2_MSG_KEXINIT, &kex_protocol_error);
ptr = sshpkt_ptr(ssh, &dlen);
if ((r = sshbuf_put(kex->peer, ptr, dlen)) != 0)
return r;
@@ -717,7 +741,7 @@ kex_input_kexinit(int type, u_int32_t seq, struct ssh *ssh)
if (!(kex->flags & KEX_INIT_SENT))
if ((r = kex_send_kexinit(ssh)) != 0)
return r;
- if ((r = kex_choose_conf(ssh)) != 0)
+ if ((r = kex_choose_conf(ssh, seq)) != 0)
return r;
if (kex->kex_type < KEX_MAX && kex->kex[kex->kex_type] != NULL)
@@ -981,20 +1005,14 @@ proposals_match(char *my[PROPOSAL_MAX], char *peer[PROPOSAL_MAX])
return (1);
}
-/* returns non-zero if proposal contains any algorithm from algs */
static int
-has_any_alg(const char *proposal, const char *algs)
+kexalgs_contains(char **peer, const char *ext)
{
- char *cp;
-
- if ((cp = match_list(proposal, algs, NULL)) == NULL)
- return 0;
- free(cp);
- return 1;
+ return has_any_alg(peer[PROPOSAL_KEX_ALGS], ext);
}
static int
-kex_choose_conf(struct ssh *ssh)
+kex_choose_conf(struct ssh *ssh, uint32_t seq)
{
struct kex *kex = ssh->kex;
struct newkeys *newkeys;
@@ -1019,13 +1037,23 @@ kex_choose_conf(struct ssh *ssh)
sprop=peer;
}
- /* Check whether client supports ext_info_c */
- if (kex->server && (kex->flags & KEX_INITIAL)) {
- char *ext;
-
- ext = match_list("ext-info-c", peer[PROPOSAL_KEX_ALGS], NULL);
- kex->ext_info_c = (ext != NULL);
- free(ext);
+ /* Check whether peer supports ext_info/kex_strict */
+ if ((kex->flags & KEX_INITIAL) != 0) {
+ if (kex->server) {
+ kex->ext_info_c = kexalgs_contains(peer, "ext-info-c");
+ kex->kex_strict = kexalgs_contains(peer,
+ "kex-strict-c-v00@openssh.com");
+ } else {
+ kex->kex_strict = kexalgs_contains(peer,
+ "kex-strict-s-v00@openssh.com");
+ }
+ if (kex->kex_strict) {
+ debug3("will use strict KEX ordering");
+ if (seq != 0)
+ ssh_packet_disconnect(ssh,
+ "strict KEX violation: "
+ "KEXINIT was not the first packet");
+ }
}
/* Check whether client supports rsa-sha2 algorithms */
diff --git a/kex.h b/kex.h
index 5f7ef784..272ebb43 100644
--- a/kex.h
+++ b/kex.h
@@ -149,6 +149,7 @@ struct kex {
u_int kex_type;
char *server_sig_algs;
int ext_info_c;
+ int kex_strict;
struct sshbuf *my;
struct sshbuf *peer;
struct sshbuf *client_version;
diff --git a/packet.c b/packet.c
index 52017def..beb214f9 100644
--- a/packet.c
+++ b/packet.c
@@ -1207,8 +1207,13 @@ ssh_packet_send2_wrapped(struct ssh *ssh)
sshbuf_dump(state->output, stderr);
#endif
/* increment sequence number for outgoing packets */
- if (++state->p_send.seqnr == 0)
+ if (++state->p_send.seqnr == 0) {
+ if ((ssh->kex->flags & KEX_INITIAL) != 0) {
+ ssh_packet_disconnect(ssh, "outgoing sequence number "
+ "wrapped during initial key exchange");
+ }
logit("outgoing seqnr wraps around");
+ }
if (++state->p_send.packets == 0)
if (!(ssh->compat & SSH_BUG_NOREKEY))
return SSH_ERR_NEED_REKEY;
@@ -1216,6 +1221,11 @@ ssh_packet_send2_wrapped(struct ssh *ssh)
state->p_send.bytes += len;
sshbuf_reset(state->outgoing_packet);
+ if (type == SSH2_MSG_NEWKEYS && ssh->kex->kex_strict) {
+ debug("resetting send seqnr %u", state->p_send.seqnr);
+ state->p_send.seqnr = 0;
+ }
+
if (type == SSH2_MSG_NEWKEYS)
r = ssh_set_newkeys(ssh, MODE_OUT);
else if (type == SSH2_MSG_USERAUTH_SUCCESS && state->server_side)
@@ -1344,8 +1354,7 @@ ssh_packet_read_seqnr(struct ssh *ssh, u_char *typep, u_int32_t *seqnr_p)
/* Stay in the loop until we have received a complete packet. */
for (;;) {
/* Try to read a packet from the buffer. */
- r = ssh_packet_read_poll_seqnr(ssh, typep, seqnr_p);
- if (r != 0)
+ if ((r = ssh_packet_read_poll_seqnr(ssh, typep, seqnr_p)) != 0)
break;
/* If we got a packet, return it. */
if (*typep != SSH_MSG_NONE)
@@ -1629,10 +1615,16 @@ ssh_packet_read_poll2(struct ssh *ssh, u_char *typep, u_int32_t *seqnr_p)
if ((r = sshbuf_consume(state->input, mac->mac_len)) != 0)
goto out;
}
+
if (seqnr_p != NULL)
*seqnr_p = state->p_read.seqnr;
- if (++state->p_read.seqnr == 0)
+ if (++state->p_read.seqnr == 0) {
+ if ((ssh->kex->flags & KEX_INITIAL) != 0) {
+ ssh_packet_disconnect(ssh, "incoming sequence number "
+ "wrapped during initial key exchange");
+ }
logit("incoming seqnr wraps around");
+ }
if (++state->p_read.packets == 0)
if (!(ssh->compat & SSH_BUG_NOREKEY))
return SSH_ERR_NEED_REKEY;
@@ -1698,6 +1690,10 @@ ssh_packet_read_poll2(struct ssh *ssh, u_char *typep, u_int32_t *seqnr_p)
#endif
/* reset for next packet */
state->packlen = 0;
+ if (*typep == SSH2_MSG_NEWKEYS && ssh->kex->kex_strict) {
+ debug("resetting read seqnr %u", state->p_read.seqnr);
+ state->p_read.seqnr = 0;
+ }
/* do we need to rekey? */
if (ssh_packet_need_rekeying(ssh, 0)) {
@@ -1720,10 +1716,39 @@ ssh_packet_read_poll_seqnr(struct ssh *ssh, u_char *typep, u_int32_t *seqnr_p)
r = ssh_packet_read_poll2(ssh, typep, seqnr_p);
if (r != 0)
return r;
- if (*typep) {
- state->keep_alive_timeouts = 0;
- DBG(debug("received packet type %d", *typep));
+ if (*typep == 0) {
+ /* no message ready */
+ return 0;
}
+ state->keep_alive_timeouts = 0;
+ DBG(debug("received packet type %d", *typep));
+
+ /* Always process disconnect messages */
+ if (*typep == SSH2_MSG_DISCONNECT) {
+ if ((r = sshpkt_get_u32(ssh, &reason)) != 0 ||
+ (r = sshpkt_get_string(ssh, &msg, NULL)) != 0)
+ return r;
+ /* Ignore normal client exit notifications */
+ do_log2(ssh->state->server_side &&
+ reason == SSH2_DISCONNECT_BY_APPLICATION ?
+ SYSLOG_LEVEL_INFO : SYSLOG_LEVEL_ERROR,
+ "Received disconnect from %s port %d:"
+ "%u: %.400s", ssh_remote_ipaddr(ssh),
+ ssh_remote_port(ssh), reason, msg);
+ free(msg);
+ return SSH_ERR_DISCONNECTED;
+ }
+
+ /*
+ * Do not implicitly handle any messages here during initial
+ * KEX when in strict mode. They will be need to be allowed
+ * explicitly by the KEX dispatch table or they will generate
+ * protocol errors.
+ */
+ if (ssh->kex != NULL &&
+ (ssh->kex->flags & KEX_INITIAL) && ssh->kex->kex_strict)
+ return 0;
+ /* Implicitly handle transport-level messages */
switch (*typep) {
case SSH2_MSG_IGNORE:
debug3("Received SSH2_MSG_IGNORE");
@@ -1738,19 +1763,6 @@ ssh_packet_read_poll_seqnr(struct ssh *ssh, u_char *typep, u_int32_t *seqnr_p)
debug("Remote: %.900s", msg);
free(msg);
break;
- case SSH2_MSG_DISCONNECT:
- if ((r = sshpkt_get_u32(ssh, &reason)) != 0 ||
- (r = sshpkt_get_string(ssh, &msg, NULL)) != 0)
- return r;
- /* Ignore normal client exit notifications */
- do_log2(ssh->state->server_side &&
- reason == SSH2_DISCONNECT_BY_APPLICATION ?
- SYSLOG_LEVEL_INFO : SYSLOG_LEVEL_ERROR,
- "Received disconnect from %s port %d:"
- "%u: %.400s", ssh_remote_ipaddr(ssh),
- ssh_remote_port(ssh), reason, msg);
- free(msg);
- return SSH_ERR_DISCONNECTED;
case SSH2_MSG_UNIMPLEMENTED:
if ((r = sshpkt_get_u32(ssh, &seqnr)) != 0)
return r;
@@ -2242,6 +2254,7 @@ kex_to_blob(struct sshbuf *m, struct kex *kex)
(r = sshbuf_put_u32(m, kex->hostkey_type)) != 0 ||
(r = sshbuf_put_u32(m, kex->hostkey_nid)) != 0 ||
(r = sshbuf_put_u32(m, kex->kex_type)) != 0 ||
+ (r = sshbuf_put_u32(m, kex->kex_strict)) != 0 ||
(r = sshbuf_put_stringb(m, kex->my)) != 0 ||
(r = sshbuf_put_stringb(m, kex->peer)) != 0 ||
(r = sshbuf_put_stringb(m, kex->client_version)) != 0 ||
@@ -2404,6 +2417,7 @@ kex_from_blob(struct sshbuf *m, struct kex **kexp)
(r = sshbuf_get_u32(m, (u_int *)&kex->hostkey_type)) != 0 ||
(r = sshbuf_get_u32(m, (u_int *)&kex->hostkey_nid)) != 0 ||
(r = sshbuf_get_u32(m, &kex->kex_type)) != 0 ||
+ (r = sshbuf_get_u32(m, &kex->kex_strict)) != 0 ||
(r = sshbuf_get_stringb(m, kex->my)) != 0 ||
(r = sshbuf_get_stringb(m, kex->peer)) != 0 ||
(r = sshbuf_get_stringb(m, kex->client_version)) != 0 ||
@@ -2732,6 +2746,7 @@ sshpkt_disconnect(struct ssh *ssh, const char *fmt,...)
vsnprintf(buf, sizeof(buf), fmt, args);
va_end(args);
+ debug2("sending SSH2_MSG_DISCONNECT: %s", buf);
if ((r = sshpkt_start(ssh, SSH2_MSG_DISCONNECT)) != 0 ||
(r = sshpkt_put_u32(ssh, SSH2_DISCONNECT_PROTOCOL_ERROR)) != 0 ||
(r = sshpkt_put_cstring(ssh, buf)) != 0 ||
diff --git a/sshconnect2.c b/sshconnect2.c
index df6caf81..0cccbcc4 100644
--- a/sshconnect2.c
+++ b/sshconnect2.c
@@ -253,7 +253,8 @@ ssh_kex2(struct ssh *ssh, char *host, st
xxx_host = host;
xxx_hostaddr = hostaddr;
- if ((s = kex_names_cat(options.kex_algorithms, "ext-info-c")) == NULL)
+ if ((s = kex_names_cat(options.kex_algorithms,
+ "ext-info-c,kex-strict-c-v00@openssh.com")) == NULL)
fatal("%s: kex_names_cat", __func__);
myproposal[PROPOSAL_KEX_ALGS] = compat_kex_proposal(s);
myproposal[PROPOSAL_ENC_ALGS_CTOS] =
@@ -358,7 +358,6 @@ struct cauthmethod {
};
static int input_userauth_service_accept(int, u_int32_t, struct ssh *);
-static int input_userauth_ext_info(int, u_int32_t, struct ssh *);
static int input_userauth_success(int, u_int32_t, struct ssh *);
static int input_userauth_failure(int, u_int32_t, struct ssh *);
static int input_userauth_banner(int, u_int32_t, struct ssh *);
@@ -472,7 +471,7 @@ ssh_userauth2(struct ssh *ssh, const char *local_user,
ssh->authctxt = &authctxt;
ssh_dispatch_init(ssh, &input_userauth_error);
- ssh_dispatch_set(ssh, SSH2_MSG_EXT_INFO, &input_userauth_ext_info);
+ ssh_dispatch_set(ssh, SSH2_MSG_EXT_INFO, kex_input_ext_info);
ssh_dispatch_set(ssh, SSH2_MSG_SERVICE_ACCEPT, &input_userauth_service_accept);
ssh_dispatch_run_fatal(ssh, DISPATCH_BLOCK, &authctxt.success); /* loop until success */
pubkey_cleanup(ssh);
@@ -531,12 +530,6 @@ input_userauth_service_accept(int type, u_int32_t seq, struct ssh *ssh)
}
/* ARGSUSED */
-static int
-input_userauth_ext_info(int type, u_int32_t seqnr, struct ssh *ssh)
-{
- return kex_input_ext_info(type, seqnr, ssh);
-}
-
void
userauth(struct ssh *ssh, char *authlist)
{
@@ -615,6 +608,7 @@ input_userauth_success(int type, u_int32_t seq, struct ssh *ssh)
free(authctxt->methoddata);
authctxt->methoddata = NULL;
authctxt->success = 1; /* break out */
+ ssh_dispatch_set(ssh, SSH2_MSG_EXT_INFO, dispatch_protocol_error);
return 0;
}
diff -up openssh-8.7p1/sshd.c.kexstrict openssh-8.7p1/sshd.c
--- openssh-8.7p1/sshd.c.kexstrict 2023-11-27 13:19:18.855433602 +0100
+++ openssh-8.7p1/sshd.c 2023-11-27 13:28:10.441325314 +0100
@@ -2531,10 +2531,14 @@ do_ssh2_kex(struct ssh *ssh)
{
char *myproposal[PROPOSAL_MAX] = { KEX_SERVER };
struct kex *kex;
+ char *cp;
int r;
- myproposal[PROPOSAL_KEX_ALGS] = compat_kex_proposal(
- options.kex_algorithms);
+ if ((cp = kex_names_cat(options.kex_algorithms,
+ "kex-strict-s-v00@openssh.com")) == NULL)
+ fatal("kex_names_cat");
+
+ myproposal[PROPOSAL_KEX_ALGS] = compat_kex_proposal(cp);
myproposal[PROPOSAL_ENC_ALGS_CTOS] = compat_cipher_proposal(
options.ciphers);
myproposal[PROPOSAL_ENC_ALGS_STOC] = compat_cipher_proposal(
@@ -2586,7 +2586,7 @@ do_ssh2_kex(struct ssh *ssh)
if (gss && orig)
xasprintf(&newstr, "%s,%s", gss, orig);
else if (gss)
- newstr = gss;
+ xasprintf(&newstr, "%s,%s", gss, "kex-strict-s-v00@openssh.com");
else if (orig)
newstr = orig;
@@ -2650,6 +2654,7 @@ do_ssh2_kex(struct ssh *ssh)
packet_send();
packet_write_wait();
#endif
+ free(cp);
debug("KEX done");
}

View File

@ -0,0 +1,57 @@
diff --git a/ssh.c b/ssh.c
index 35c48e62..48d93ddf 100644
--- a/ssh.c
+++ b/ssh.c
@@ -626,6 +626,41 @@ ssh_conn_info_free(struct ssh_conn_info *cinfo)
}
}
+static int
+valid_hostname(const char *s)
+{
+ size_t i;
+
+ if (*s == '-')
+ return 0;
+ for (i = 0; s[i] != 0; i++) {
+ if (strchr("'`\"$\\;&<>|(){}", s[i]) != NULL ||
+ isspace((u_char)s[i]) || iscntrl((u_char)s[i]))
+ return 0;
+ }
+ return 1;
+}
+
+static int
+valid_ruser(const char *s)
+{
+ size_t i;
+
+ if (*s == '-')
+ return 0;
+ for (i = 0; s[i] != 0; i++) {
+ if (strchr("'`\";&<>|(){}", s[i]) != NULL)
+ return 0;
+ /* Disallow '-' after whitespace */
+ if (isspace((u_char)s[i]) && s[i + 1] == '-')
+ return 0;
+ /* Disallow \ in last position */
+ if (s[i] == '\\' && s[i + 1] == '\0')
+ return 0;
+ }
+ return 1;
+}
+
/*
* Main program for the ssh client.
*/
@@ -1118,6 +1153,10 @@ main(int ac, char **av)
if (!host)
usage();
+ if (!valid_hostname(host))
+ fatal("hostname contains invalid characters");
+ if (options.user != NULL && !valid_ruser(options.user))
+ fatal("remote username contains invalid characters");
host_arg = xstrdup(host);
/* Initialize the command to execute on remote host. */

View File

@ -66,7 +66,7 @@
# Do not forget to bump pam_ssh_agent_auth release if you rewind the main package release to 1
%global openssh_ver 8.0p1
%global openssh_rel 17
%global openssh_rel 24
%global pam_ssh_agent_ver 0.10.3
%global pam_ssh_agent_rel 7
@ -277,6 +277,21 @@ Patch985: openssh-8.7p1-minimize-sha1-use.patch
Patch986: openssh-9.1p1-sshbanner.patch
# Upstream 25e3bccbaa63d27b9d5e09c123f1eb28594d2bd6
Patch987: openssh-8.0p1-ipv6-process.patch
# Upstream 4332b4fe49360679647a8705bc08f4e81323f6b4
Patch988: openssh-8.0p1-avoidkillall.patch
# Upstream 89b54900ac61986760452f132bbe3fb7249cfdac
Patch989: openssh-8.0p1-bigsshdconfig.patch
# upsream commit
# b23fe83f06ee7e721033769cfa03ae840476d280
Patch1015: openssh-9.3p1-upstream-cve-2023-38408.patch
#upstream commit 01dbf3d46651b7d6ddf5e45d233839bbfffaeaec
Patch1017: openssh-9.4p2-limit-delay.patch
#upstream commit 1edb00c58f8a6875fad6a497aa2bacf37f9e6cd5
Patch1018: openssh-9.6p1-CVE-2023-48795.patch
#upstream commit 7ef3787c84b6b524501211b11a26c742f829af1a
Patch1019: openssh-9.6p1-CVE-2023-51385.patch
# SCP kill switch
Patch1020: openssh-8.7p1-scp-kill-switch.patch
License: BSD
Group: Applications/Internet
@ -510,6 +525,8 @@ popd
%patch985 -p1 -b .minimize-sha1-use
%patch986 -p1 -b .banner
%patch987 -p1 -b .sftp_ipv6
%patch988 -p1 -b .killall
%patch989 -p1 -b .bigsshdconfig
%patch200 -p1 -b .audit
%patch201 -p1 -b .audit-race
@ -517,6 +534,12 @@ popd
%patch100 -p1 -b .coverity
%patch1015 -p1 -b .cve-2023-38408
%patch1017 -p1 -b .limitdelay
%patch1018 -p1 -b .cve-2023-48795
%patch1019 -p1 -b .cve-2023-51385
%patch1020 -p1 -b .scp-kill-switch
autoreconf
pushd pam_ssh_agent_auth-%{pam_ssh_agent_ver}
autoreconf
@ -801,6 +824,46 @@ getent passwd sshd >/dev/null || \
%endif
%changelog
* Tue Feb 06 2024 Dmitry Belyavskiy <dbelyavs@redhat.com> - 8.0p1-24
- Providing a kill switch for scp to deal with CVE-2020-15778
Resolves: RHEL-22870
* Fri Jan 05 2024 Dmitry Belyavskiy <dbelyavs@redhat.com> - 8.0p1-23
- Fix Terrapin attack
Resolves: RHEL-19308
* Thu Dec 21 2023 Dmitry Belyavskiy <dbelyavs@redhat.com> - 8.0p1-22
- Fix Terrapin attack
Resolves: RHEL-19308
- Forbid shell metasymbols in username/hostname
Resolves: RHEL-19788
* Tue Nov 07 2023 Dmitry Belyavskiy <dbelyavs@redhat.com> - 8.0p1-21
- Using DigestSign/DigestVerify functions for better FIPS compatibility
Resolves: RHEL-5217
* Mon Oct 30 2023 Dmitry Belyavskiy <dbelyavs@redhat.com> - 8.0p1-20
- Limit artificial delays in sshd while login using AD user
Resolves: RHEL-1684
- Add comment to OpenSSH server config about FIPS-incompatible key
Resolves: RHEL-5221
- Avoid killing all processes on system in case of race condition
Resolves: RHEL-11548
- Avoid sshd_config 256K limit
Resolves: RHEL-5279
- Using DigestSign/DigestVerify functions for better FIPS compatibility
Resolves: RHEL-5217
- Fix GSS KEX causing ssh failures when connecting to WinSSHD
Resolves: RHEL-5321
* Thu Aug 24 2023 Dmitry Belyavskiy <dbelyavs@redhat.com> - 8.0p1-19
- rebuilt
Related: CVE-2023-38408
* Thu Jul 20 2023 Dmitry Belyavskiy <dbelyavs@redhat.com> - 8.0p1-18
- Avoid remote code execution in ssh-agent PKCS#11 support
Resolves: CVE-2023-38408
* Tue Dec 20 2022 Dmitry Belyavskiy - 8.0p1-17
- Fix parsing of IPv6 IPs in sftp client (#2151334)
- Avoid ssh banner one-byte overflow (#2138344)