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-rw-r--r--ssh-agent.c1132
1 files changed, 597 insertions, 535 deletions
diff --git a/ssh-agent.c b/ssh-agent.c
index aeda656a..e081413b 100644
--- a/ssh-agent.c
+++ b/ssh-agent.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: ssh-agent.c,v 1.199 2015/03/04 21:12:59 djm Exp $ */
+/* $OpenBSD: ssh-agent.c,v 1.257 2020/03/06 18:28:27 markus Exp $ */
/*
* Author: Tatu Ylonen <ylo@cs.hut.fi>
* Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
@@ -36,12 +36,12 @@
#include "includes.h"
-#include <sys/param.h> /* MIN MAX */
#include <sys/types.h>
#include <sys/param.h>
#include <sys/resource.h>
#include <sys/stat.h>
#include <sys/socket.h>
+#include <sys/wait.h>
#ifdef HAVE_SYS_TIME_H
# include <sys/time.h>
#endif
@@ -61,6 +61,9 @@
#ifdef HAVE_PATHS_H
# include <paths.h>
#endif
+#ifdef HAVE_POLL_H
+# include <poll.h>
+#endif
#include <signal.h>
#include <stdarg.h>
#include <stdio.h>
@@ -68,13 +71,12 @@
#include <time.h>
#include <string.h>
#include <unistd.h>
-
-#include "key.h" /* XXX for typedef */
-#include "buffer.h" /* XXX for typedef */
+#ifdef HAVE_UTIL_H
+# include <util.h>
+#endif
#include "xmalloc.h"
#include "ssh.h"
-#include "rsa.h"
#include "sshbuf.h"
#include "sshkey.h"
#include "authfd.h"
@@ -83,15 +85,22 @@
#include "misc.h"
#include "digest.h"
#include "ssherr.h"
-
-#ifdef ENABLE_PKCS11
+#include "match.h"
+#include "msg.h"
+#include "ssherr.h"
+#include "pathnames.h"
#include "ssh-pkcs11.h"
-#endif
+#include "sk-api.h"
-#if defined(HAVE_SYS_PRCTL_H)
-#include <sys/prctl.h> /* For prctl() and PR_SET_DUMPABLE */
+#ifndef DEFAULT_PROVIDER_WHITELIST
+# define DEFAULT_PROVIDER_WHITELIST "/usr/lib*/*,/usr/local/lib*/*"
#endif
+/* Maximum accepted message length */
+#define AGENT_MAX_LEN (256*1024)
+/* Maximum bytes to read from client socket */
+#define AGENT_RBUF_LEN (4096)
+
typedef enum {
AUTH_UNUSED,
AUTH_SOCKET,
@@ -116,15 +125,16 @@ typedef struct identity {
char *provider;
time_t death;
u_int confirm;
+ char *sk_provider;
} Identity;
-typedef struct {
+struct idtable {
int nentries;
TAILQ_HEAD(idqueue, identity) idlist;
-} Idtab;
+};
-/* private key table, one per protocol version */
-Idtab idtable[3];
+/* private key table */
+struct idtable *idtab;
int max_fd = 0;
@@ -139,9 +149,16 @@ pid_t cleanup_pid = 0;
char socket_name[PATH_MAX];
char socket_dir[PATH_MAX];
+/* PKCS#11/Security key path whitelist */
+static char *provider_whitelist;
+
/* locking */
+#define LOCK_SIZE 32
+#define LOCK_SALT_SIZE 16
+#define LOCK_ROUNDS 1
int locked = 0;
-char *lock_passwd = NULL;
+u_char lock_pwhash[LOCK_SIZE];
+u_char lock_salt[LOCK_SALT_SIZE];
extern char *__progname;
@@ -164,21 +181,9 @@ close_socket(SocketEntry *e)
static void
idtab_init(void)
{
- int i;
-
- for (i = 0; i <=2; i++) {
- TAILQ_INIT(&idtable[i].idlist);
- idtable[i].nentries = 0;
- }
-}
-
-/* return private key table for requested protocol version */
-static Idtab *
-idtab_lookup(int version)
-{
- if (version < 1 || version > 2)
- fatal("internal error, bad protocol version %d", version);
- return &idtable[version];
+ idtab = xcalloc(1, sizeof(*idtab));
+ TAILQ_INIT(&idtab->idlist);
+ idtab->nentries = 0;
}
static void
@@ -187,17 +192,17 @@ free_identity(Identity *id)
sshkey_free(id->key);
free(id->provider);
free(id->comment);
+ free(id->sk_provider);
free(id);
}
/* return matching private key for given public key */
static Identity *
-lookup_identity(struct sshkey *key, int version)
+lookup_identity(struct sshkey *key)
{
Identity *id;
- Idtab *tab = idtab_lookup(version);
- TAILQ_FOREACH(id, &tab->idlist, next) {
+ TAILQ_FOREACH(id, &idtab->idlist, next) {
if (sshkey_equal(key, id->key))
return (id);
}
@@ -234,161 +239,74 @@ send_status(SocketEntry *e, int success)
/* send list of supported public keys to 'client' */
static void
-process_request_identities(SocketEntry *e, int version)
+process_request_identities(SocketEntry *e)
{
- Idtab *tab = idtab_lookup(version);
Identity *id;
struct sshbuf *msg;
int r;
if ((msg = sshbuf_new()) == NULL)
fatal("%s: sshbuf_new failed", __func__);
- if ((r = sshbuf_put_u8(msg, (version == 1) ?
- SSH_AGENT_RSA_IDENTITIES_ANSWER :
- SSH2_AGENT_IDENTITIES_ANSWER)) != 0 ||
- (r = sshbuf_put_u32(msg, tab->nentries)) != 0)
+ if ((r = sshbuf_put_u8(msg, SSH2_AGENT_IDENTITIES_ANSWER)) != 0 ||
+ (r = sshbuf_put_u32(msg, idtab->nentries)) != 0)
fatal("%s: buffer error: %s", __func__, ssh_err(r));
- TAILQ_FOREACH(id, &tab->idlist, next) {
- if (id->key->type == KEY_RSA1) {
-#ifdef WITH_SSH1
- if ((r = sshbuf_put_u32(msg,
- BN_num_bits(id->key->rsa->n))) != 0 ||
- (r = sshbuf_put_bignum1(msg,
- id->key->rsa->e)) != 0 ||
- (r = sshbuf_put_bignum1(msg,
- id->key->rsa->n)) != 0)
- fatal("%s: buffer error: %s",
- __func__, ssh_err(r));
-#endif
- } else {
- u_char *blob;
- size_t blen;
-
- if ((r = sshkey_to_blob(id->key, &blob, &blen)) != 0) {
- error("%s: sshkey_to_blob: %s", __func__,
- ssh_err(r));
- continue;
- }
- if ((r = sshbuf_put_string(msg, blob, blen)) != 0)
- fatal("%s: buffer error: %s",
- __func__, ssh_err(r));
- free(blob);
+ TAILQ_FOREACH(id, &idtab->idlist, next) {
+ if ((r = sshkey_puts_opts(id->key, msg, SSHKEY_SERIALIZE_INFO))
+ != 0 ||
+ (r = sshbuf_put_cstring(msg, id->comment)) != 0) {
+ error("%s: put key/comment: %s", __func__,
+ ssh_err(r));
+ continue;
}
- if ((r = sshbuf_put_cstring(msg, id->comment)) != 0)
- fatal("%s: buffer error: %s", __func__, ssh_err(r));
}
if ((r = sshbuf_put_stringb(e->output, msg)) != 0)
fatal("%s: buffer error: %s", __func__, ssh_err(r));
sshbuf_free(msg);
}
-#ifdef WITH_SSH1
-/* ssh1 only */
-static void
-process_authentication_challenge1(SocketEntry *e)
-{
- u_char buf[32], mdbuf[16], session_id[16];
- u_int response_type;
- BIGNUM *challenge;
- Identity *id;
- int r, len;
- struct sshbuf *msg;
- struct ssh_digest_ctx *md;
- struct sshkey *key;
-
- if ((msg = sshbuf_new()) == NULL)
- fatal("%s: sshbuf_new failed", __func__);
- if ((key = sshkey_new(KEY_RSA1)) == NULL)
- fatal("%s: sshkey_new failed", __func__);
- if ((challenge = BN_new()) == NULL)
- fatal("%s: BN_new failed", __func__);
-
- if ((r = sshbuf_get_u32(e->request, NULL)) != 0 || /* ignored */
- (r = sshbuf_get_bignum1(e->request, key->rsa->e)) != 0 ||
- (r = sshbuf_get_bignum1(e->request, key->rsa->n)) != 0 ||
- (r = sshbuf_get_bignum1(e->request, challenge)))
- fatal("%s: buffer error: %s", __func__, ssh_err(r));
-
- /* Only protocol 1.1 is supported */
- if (sshbuf_len(e->request) == 0)
- goto failure;
- if ((r = sshbuf_get(e->request, session_id, sizeof(session_id))) != 0 ||
- (r = sshbuf_get_u32(e->request, &response_type)) != 0)
- fatal("%s: buffer error: %s", __func__, ssh_err(r));
- if (response_type != 1)
- goto failure;
-
- id = lookup_identity(key, 1);
- if (id != NULL && (!id->confirm || confirm_key(id) == 0)) {
- struct sshkey *private = id->key;
- /* Decrypt the challenge using the private key. */
- if ((r = rsa_private_decrypt(challenge, challenge,
- private->rsa) != 0)) {
- fatal("%s: rsa_public_encrypt: %s", __func__,
- ssh_err(r));
- goto failure; /* XXX ? */
- }
- /* The response is MD5 of decrypted challenge plus session id */
- len = BN_num_bytes(challenge);
- if (len <= 0 || len > 32) {
- logit("%s: bad challenge length %d", __func__, len);
- goto failure;
- }
- memset(buf, 0, 32);
- BN_bn2bin(challenge, buf + 32 - len);
- if ((md = ssh_digest_start(SSH_DIGEST_MD5)) == NULL ||
- ssh_digest_update(md, buf, 32) < 0 ||
- ssh_digest_update(md, session_id, 16) < 0 ||
- ssh_digest_final(md, mdbuf, sizeof(mdbuf)) < 0)
- fatal("%s: md5 failed", __func__);
- ssh_digest_free(md);
-
- /* Send the response. */
- if ((r = sshbuf_put_u8(msg, SSH_AGENT_RSA_RESPONSE)) != 0 ||
- (r = sshbuf_put(msg, mdbuf, sizeof(mdbuf))) != 0)
- fatal("%s: buffer error: %s", __func__, ssh_err(r));
- goto send;
+static char *
+agent_decode_alg(struct sshkey *key, u_int flags)
+{
+ if (key->type == KEY_RSA) {
+ if (flags & SSH_AGENT_RSA_SHA2_256)
+ return "rsa-sha2-256";
+ else if (flags & SSH_AGENT_RSA_SHA2_512)
+ return "rsa-sha2-512";
+ } else if (key->type == KEY_RSA_CERT) {
+ if (flags & SSH_AGENT_RSA_SHA2_256)
+ return "rsa-sha2-256-cert-v01@openssh.com";
+ else if (flags & SSH_AGENT_RSA_SHA2_512)
+ return "rsa-sha2-512-cert-v01@openssh.com";
}
-
- failure:
- /* Unknown identity or protocol error. Send failure. */
- if ((r = sshbuf_put_u8(msg, SSH_AGENT_FAILURE)) != 0)
- fatal("%s: buffer error: %s", __func__, ssh_err(r));
- send:
- if ((r = sshbuf_put_stringb(e->output, msg)) != 0)
- fatal("%s: buffer error: %s", __func__, ssh_err(r));
- sshkey_free(key);
- BN_clear_free(challenge);
- sshbuf_free(msg);
+ return NULL;
}
-#endif
/* ssh2 only */
static void
process_sign_request2(SocketEntry *e)
{
- u_char *blob, *data, *signature = NULL;
- size_t blen, dlen, slen = 0;
+ const u_char *data;
+ u_char *signature = NULL;
+ size_t dlen, slen = 0;
u_int compat = 0, flags;
int r, ok = -1;
+ char *fp = NULL;
struct sshbuf *msg;
- struct sshkey *key;
+ struct sshkey *key = NULL;
struct identity *id;
+ struct notifier_ctx *notifier = NULL;
if ((msg = sshbuf_new()) == NULL)
fatal("%s: sshbuf_new failed", __func__);
- if ((r = sshbuf_get_string(e->request, &blob, &blen)) != 0 ||
- (r = sshbuf_get_string(e->request, &data, &dlen)) != 0 ||
- (r = sshbuf_get_u32(e->request, &flags)) != 0)
- fatal("%s: buffer error: %s", __func__, ssh_err(r));
- if (flags & SSH_AGENT_OLD_SIGNATURE)
- compat = SSH_BUG_SIGBLOB;
- if ((r = sshkey_from_blob(blob, blen, &key)) != 0) {
- error("%s: cannot parse key blob: %s", __func__, ssh_err(ok));
+ if ((r = sshkey_froms(e->request, &key)) != 0 ||
+ (r = sshbuf_get_string_direct(e->request, &data, &dlen)) != 0 ||
+ (r = sshbuf_get_u32(e->request, &flags)) != 0) {
+ error("%s: couldn't parse request: %s", __func__, ssh_err(r));
goto send;
}
- if ((id = lookup_identity(key, 2)) == NULL) {
+
+ if ((id = lookup_identity(key)) == NULL) {
verbose("%s: %s key not found", __func__, sshkey_type(key));
goto send;
}
@@ -396,15 +314,27 @@ process_sign_request2(SocketEntry *e)
verbose("%s: user refused key", __func__);
goto send;
}
+ if (sshkey_is_sk(id->key) &&
+ (id->key->sk_flags & SSH_SK_USER_PRESENCE_REQD)) {
+ if ((fp = sshkey_fingerprint(key, SSH_FP_HASH_DEFAULT,
+ SSH_FP_DEFAULT)) == NULL)
+ fatal("%s: fingerprint failed", __func__);
+ notifier = notify_start(0,
+ "Confirm user presence for key %s %s",
+ sshkey_type(id->key), fp);
+ }
if ((r = sshkey_sign(id->key, &signature, &slen,
- data, dlen, compat)) != 0) {
- error("%s: sshkey_sign: %s", __func__, ssh_err(ok));
+ data, dlen, agent_decode_alg(key, flags),
+ id->sk_provider, compat)) != 0) {
+ error("%s: sshkey_sign: %s", __func__, ssh_err(r));
goto send;
}
/* Success */
ok = 0;
send:
+ notify_complete(notifier);
sshkey_free(key);
+ free(fp);
if (ok == 0) {
if ((r = sshbuf_put_u8(msg, SSH2_AGENT_SIGN_RESPONSE)) != 0 ||
(r = sshbuf_put_string(msg, signature, slen)) != 0)
@@ -416,90 +346,52 @@ process_sign_request2(SocketEntry *e)
fatal("%s: buffer error: %s", __func__, ssh_err(r));
sshbuf_free(msg);
- free(data);
- free(blob);
free(signature);
}
/* shared */
static void
-process_remove_identity(SocketEntry *e, int version)
+process_remove_identity(SocketEntry *e)
{
- size_t blen;
int r, success = 0;
struct sshkey *key = NULL;
- u_char *blob;
-#ifdef WITH_SSH1
- u_int bits;
-#endif /* WITH_SSH1 */
-
- switch (version) {
-#ifdef WITH_SSH1
- case 1:
- if ((key = sshkey_new(KEY_RSA1)) == NULL) {
- error("%s: sshkey_new failed", __func__);
- return;
- }
- if ((r = sshbuf_get_u32(e->request, &bits)) != 0 ||
- (r = sshbuf_get_bignum1(e->request, key->rsa->e)) != 0 ||
- (r = sshbuf_get_bignum1(e->request, key->rsa->n)) != 0)
- fatal("%s: buffer error: %s", __func__, ssh_err(r));
+ Identity *id;
- if (bits != sshkey_size(key))
- logit("Warning: identity keysize mismatch: "
- "actual %u, announced %u",
- sshkey_size(key), bits);
- break;
-#endif /* WITH_SSH1 */
- case 2:
- if ((r = sshbuf_get_string(e->request, &blob, &blen)) != 0)
- fatal("%s: buffer error: %s", __func__, ssh_err(r));
- if ((r = sshkey_from_blob(blob, blen, &key)) != 0)
- error("%s: sshkey_from_blob failed: %s",
- __func__, ssh_err(r));
- free(blob);
- break;
+ if ((r = sshkey_froms(e->request, &key)) != 0) {
+ error("%s: get key: %s", __func__, ssh_err(r));
+ goto done;
}
- if (key != NULL) {
- Identity *id = lookup_identity(key, version);
- if (id != NULL) {
- /*
- * We have this key. Free the old key. Since we
- * don't want to leave empty slots in the middle of
- * the array, we actually free the key there and move
- * all the entries between the empty slot and the end
- * of the array.
- */
- Idtab *tab = idtab_lookup(version);
- if (tab->nentries < 1)
- fatal("process_remove_identity: "
- "internal error: tab->nentries %d",
- tab->nentries);
- TAILQ_REMOVE(&tab->idlist, id, next);
- free_identity(id);
- tab->nentries--;
- success = 1;
- }
- sshkey_free(key);
+ if ((id = lookup_identity(key)) == NULL) {
+ debug("%s: key not found", __func__);
+ goto done;
}
+ /* We have this key, free it. */
+ if (idtab->nentries < 1)
+ fatal("%s: internal error: nentries %d",
+ __func__, idtab->nentries);
+ TAILQ_REMOVE(&idtab->idlist, id, next);
+ free_identity(id);
+ idtab->nentries--;
+ sshkey_free(key);
+ success = 1;
+ done:
send_status(e, success);
}
static void
-process_remove_all_identities(SocketEntry *e, int version)
+process_remove_all_identities(SocketEntry *e)
{
- Idtab *tab = idtab_lookup(version);
Identity *id;
/* Loop over all identities and clear the keys. */
- for (id = TAILQ_FIRST(&tab->idlist); id;
- id = TAILQ_FIRST(&tab->idlist)) {
- TAILQ_REMOVE(&tab->idlist, id, next);
+ for (id = TAILQ_FIRST(&idtab->idlist); id;
+ id = TAILQ_FIRST(&idtab->idlist)) {
+ TAILQ_REMOVE(&idtab->idlist, id, next);
free_identity(id);
}
/* Mark that there are no identities. */
- tab->nentries = 0;
+ idtab->nentries = 0;
/* Send success. */
send_status(e, 1);
@@ -511,24 +403,19 @@ reaper(void)
{
time_t deadline = 0, now = monotime();
Identity *id, *nxt;
- int version;
- Idtab *tab;
-
- for (version = 1; version < 3; version++) {
- tab = idtab_lookup(version);
- for (id = TAILQ_FIRST(&tab->idlist); id; id = nxt) {
- nxt = TAILQ_NEXT(id, next);
- if (id->death == 0)
- continue;
- if (now >= id->death) {
- debug("expiring key '%s'", id->comment);
- TAILQ_REMOVE(&tab->idlist, id, next);
- free_identity(id);
- tab->nentries--;
- } else
- deadline = (deadline == 0) ? id->death :
- MIN(deadline, id->death);
- }
+
+ for (id = TAILQ_FIRST(&idtab->idlist); id; id = nxt) {
+ nxt = TAILQ_NEXT(id, next);
+ if (id->death == 0)
+ continue;
+ if (now >= id->death) {
+ debug("expiring key '%s'", id->comment);
+ TAILQ_REMOVE(&idtab->idlist, id, next);
+ free_identity(id);
+ idtab->nentries--;
+ } else
+ deadline = (deadline == 0) ? id->death :
+ MINIMUM(deadline, id->death);
}
if (deadline == 0 || deadline <= now)
return 0;
@@ -536,79 +423,25 @@ reaper(void)
return (deadline - now);
}
-/*
- * XXX this and the corresponding serialisation function probably belongs
- * in key.c
- */
-#ifdef WITH_SSH1
-static int
-agent_decode_rsa1(struct sshbuf *m, struct sshkey **kp)
-{
- struct sshkey *k = NULL;
- int r = SSH_ERR_INTERNAL_ERROR;
-
- *kp = NULL;
- if ((k = sshkey_new_private(KEY_RSA1)) == NULL)
- return SSH_ERR_ALLOC_FAIL;
-
- if ((r = sshbuf_get_u32(m, NULL)) != 0 || /* ignored */
- (r = sshbuf_get_bignum1(m, k->rsa->n)) != 0 ||
- (r = sshbuf_get_bignum1(m, k->rsa->e)) != 0 ||
- (r = sshbuf_get_bignum1(m, k->rsa->d)) != 0 ||
- (r = sshbuf_get_bignum1(m, k->rsa->iqmp)) != 0 ||
- /* SSH1 and SSL have p and q swapped */
- (r = sshbuf_get_bignum1(m, k->rsa->q)) != 0 || /* p */
- (r = sshbuf_get_bignum1(m, k->rsa->p)) != 0) /* q */
- goto out;
-
- /* Generate additional parameters */
- if ((r = rsa_generate_additional_parameters(k->rsa)) != 0)
- goto out;
- /* enable blinding */
- if (RSA_blinding_on(k->rsa, NULL) != 1) {
- r = SSH_ERR_LIBCRYPTO_ERROR;
- goto out;
- }
-
- r = 0; /* success */
- out:
- if (r == 0)
- *kp = k;
- else
- sshkey_free(k);
- return r;
-}
-#endif /* WITH_SSH1 */
-
static void
-process_add_identity(SocketEntry *e, int version)
+process_add_identity(SocketEntry *e)
{
- Idtab *tab = idtab_lookup(version);
Identity *id;
int success = 0, confirm = 0;
- u_int seconds;
- char *comment = NULL;
+ u_int seconds = 0, maxsign;
+ char *fp, *comment = NULL, *ext_name = NULL, *sk_provider = NULL;
+ char canonical_provider[PATH_MAX];
time_t death = 0;
struct sshkey *k = NULL;
u_char ctype;
int r = SSH_ERR_INTERNAL_ERROR;
- switch (version) {
-#ifdef WITH_SSH1
- case 1:
- r = agent_decode_rsa1(e->request, &k);
- break;
-#endif /* WITH_SSH1 */
- case 2:
- r = sshkey_private_deserialize(e->request, &k);
- break;
- }
- if (r != 0 || k == NULL ||
+ if ((r = sshkey_private_deserialize(e->request, &k)) != 0 ||
+ k == NULL ||
(r = sshbuf_get_cstring(e->request, &comment, NULL)) != 0) {
error("%s: decode private key: %s", __func__, ssh_err(r));
goto err;
}
-
while (sshbuf_len(e->request)) {
if ((r = sshbuf_get_u8(e->request, &ctype)) != 0) {
error("%s: buffer error: %s", __func__, ssh_err(r));
@@ -626,32 +459,115 @@ process_add_identity(SocketEntry *e, int version)
case SSH_AGENT_CONSTRAIN_CONFIRM:
confirm = 1;
break;
+ case SSH_AGENT_CONSTRAIN_MAXSIGN:
+ if ((r = sshbuf_get_u32(e->request, &maxsign)) != 0) {
+ error("%s: bad maxsign constraint: %s",
+ __func__, ssh_err(r));
+ goto err;
+ }
+ if ((r = sshkey_enable_maxsign(k, maxsign)) != 0) {
+ error("%s: cannot enable maxsign: %s",
+ __func__, ssh_err(r));
+ goto err;
+ }
+ break;
+ case SSH_AGENT_CONSTRAIN_EXTENSION:
+ if ((r = sshbuf_get_cstring(e->request,
+ &ext_name, NULL)) != 0) {
+ error("%s: cannot parse extension: %s",
+ __func__, ssh_err(r));
+ goto err;
+ }
+ debug("%s: constraint ext %s", __func__, ext_name);
+ if (strcmp(ext_name, "sk-provider@openssh.com") == 0) {
+ if (sk_provider != NULL) {
+ error("%s already set", ext_name);
+ goto err;
+ }
+ if ((r = sshbuf_get_cstring(e->request,
+ &sk_provider, NULL)) != 0) {
+ error("%s: cannot parse %s: %s",
+ __func__, ext_name, ssh_err(r));
+ goto err;
+ }
+ } else {
+ error("%s: unsupported constraint \"%s\"",
+ __func__, ext_name);
+ goto err;
+ }
+ free(ext_name);
+ break;
default:
error("%s: Unknown constraint %d", __func__, ctype);
err:
+ free(sk_provider);
+ free(ext_name);
sshbuf_reset(e->request);
free(comment);
sshkey_free(k);
goto send;
}
}
+ if (sk_provider != NULL) {
+ if (!sshkey_is_sk(k)) {
+ error("Cannot add provider: %s is not an "
+ "authenticator-hosted key", sshkey_type(k));
+ free(sk_provider);
+ goto send;
+ }
+ if (strcasecmp(sk_provider, "internal") == 0) {
+ debug("%s: internal provider", __func__);
+ } else {
+ if (realpath(sk_provider, canonical_provider) == NULL) {
+ verbose("failed provider \"%.100s\": "
+ "realpath: %s", sk_provider,
+ strerror(errno));
+ free(sk_provider);
+ goto send;
+ }
+ free(sk_provider);
+ sk_provider = xstrdup(canonical_provider);
+ if (match_pattern_list(sk_provider,
+ provider_whitelist, 0) != 1) {
+ error("Refusing add key: "
+ "provider %s not whitelisted", sk_provider);
+ free(sk_provider);
+ goto send;
+ }
+ }
+ }
+ if ((r = sshkey_shield_private(k)) != 0) {
+ error("%s: shield private key: %s", __func__, ssh_err(r));
+ goto err;
+ }
success = 1;
if (lifetime && !death)
death = monotime() + lifetime;
- if ((id = lookup_identity(k, version)) == NULL) {
+ if ((id = lookup_identity(k)) == NULL) {
id = xcalloc(1, sizeof(Identity));
- id->key = k;
- TAILQ_INSERT_TAIL(&tab->idlist, id, next);
+ TAILQ_INSERT_TAIL(&idtab->idlist, id, next);
/* Increment the number of identities. */
- tab->nentries++;
+ idtab->nentries++;
} else {
- sshkey_free(k);
+ /* key state might have been updated */
+ sshkey_free(id->key);
free(id->comment);
+ free(id->sk_provider);
}
+ id->key = k;
id->comment = comment;
id->death = death;
id->confirm = confirm;
+ id->sk_provider = sk_provider;
+
+ if ((fp = sshkey_fingerprint(k, SSH_FP_HASH_DEFAULT,
+ SSH_FP_DEFAULT)) == NULL)
+ fatal("%s: sshkey_fingerprint failed", __func__);
+ debug("%s: add %s %s \"%.100s\" (life: %u) (confirm: %u) "
+ "(provider: %s)", __func__, sshkey_ssh_name(k), fp, comment,
+ seconds, confirm, sk_provider == NULL ? "none" : sk_provider);
+ free(fp);
send:
send_status(e, success);
}
@@ -660,39 +576,63 @@ send:
static void
process_lock_agent(SocketEntry *e, int lock)
{
- int r, success = 0;
+ int r, success = 0, delay;
char *passwd;
+ u_char passwdhash[LOCK_SIZE];
+ static u_int fail_count = 0;
+ size_t pwlen;
- if ((r = sshbuf_get_cstring(e->request, &passwd, NULL)) != 0)
+ /*
+ * This is deliberately fatal: the user has requested that we lock,
+ * but we can't parse their request properly. The only safe thing to
+ * do is abort.
+ */
+ if ((r = sshbuf_get_cstring(e->request, &passwd, &pwlen)) != 0)
fatal("%s: buffer error: %s", __func__, ssh_err(r));
- if (locked && !lock && strcmp(passwd, lock_passwd) == 0) {
- locked = 0;
- explicit_bzero(lock_passwd, strlen(lock_passwd));
- free(lock_passwd);
- lock_passwd = NULL;
- success = 1;
+ if (pwlen == 0) {
+ debug("empty password not supported");
+ } else if (locked && !lock) {
+ if (bcrypt_pbkdf(passwd, pwlen, lock_salt, sizeof(lock_salt),
+ passwdhash, sizeof(passwdhash), LOCK_ROUNDS) < 0)
+ fatal("bcrypt_pbkdf");
+ if (timingsafe_bcmp(passwdhash, lock_pwhash, LOCK_SIZE) == 0) {
+ debug("agent unlocked");
+ locked = 0;
+ fail_count = 0;
+ explicit_bzero(lock_pwhash, sizeof(lock_pwhash));
+ success = 1;
+ } else {
+ /* delay in 0.1s increments up to 10s */
+ if (fail_count < 100)
+ fail_count++;
+ delay = 100000 * fail_count;
+ debug("unlock failed, delaying %0.1lf seconds",
+ (double)delay/1000000);
+ usleep(delay);
+ }
+ explicit_bzero(passwdhash, sizeof(passwdhash));
} else if (!locked && lock) {
+ debug("agent locked");
locked = 1;
- lock_passwd = xstrdup(passwd);
+ arc4random_buf(lock_salt, sizeof(lock_salt));
+ if (bcrypt_pbkdf(passwd, pwlen, lock_salt, sizeof(lock_salt),
+ lock_pwhash, sizeof(lock_pwhash), LOCK_ROUNDS) < 0)
+ fatal("bcrypt_pbkdf");
success = 1;
}
- explicit_bzero(passwd, strlen(passwd));
- free(passwd);
+ freezero(passwd, pwlen);
send_status(e, success);
}
static void
-no_identities(SocketEntry *e, u_int type)
+no_identities(SocketEntry *e)
{
struct sshbuf *msg;
int r;
if ((msg = sshbuf_new()) == NULL)
fatal("%s: sshbuf_new failed", __func__);
- if ((r = sshbuf_put_u8(msg,
- (type == SSH_AGENTC_REQUEST_RSA_IDENTITIES) ?
- SSH_AGENT_RSA_IDENTITIES_ANSWER :
- SSH2_AGENT_IDENTITIES_ANSWER)) != 0 ||
+ if ((r = sshbuf_put_u8(msg, SSH2_AGENT_IDENTITIES_ANSWER)) != 0 ||
(r = sshbuf_put_u32(msg, 0)) != 0 ||
(r = sshbuf_put_stringb(e->output, msg)) != 0)
fatal("%s: buffer error: %s", __func__, ssh_err(r));
@@ -703,100 +643,125 @@ no_identities(SocketEntry *e, u_int type)
static void
process_add_smartcard_key(SocketEntry *e)
{
- char *provider = NULL, *pin;
- int r, i, version, count = 0, success = 0, confirm = 0;
+ char *provider = NULL, *pin = NULL, canonical_provider[PATH_MAX];
+ char **comments = NULL;
+ int r, i, count = 0, success = 0, confirm = 0;
u_int seconds;
time_t death = 0;
u_char type;
struct sshkey **keys = NULL, *k;
Identity *id;
- Idtab *tab;
if ((r = sshbuf_get_cstring(e->request, &provider, NULL)) != 0 ||
- (r = sshbuf_get_cstring(e->request, &pin, NULL)) != 0)
- fatal("%s: buffer error: %s", __func__, ssh_err(r));
+ (r = sshbuf_get_cstring(e->request, &pin, NULL)) != 0) {
+ error("%s: buffer error: %s", __func__, ssh_err(r));
+ goto send;
+ }
while (sshbuf_len(e->request)) {
- if ((r = sshbuf_get_u8(e->request, &type)) != 0)
- fatal("%s: buffer error: %s", __func__, ssh_err(r));
+ if ((r = sshbuf_get_u8(e->request, &type)) != 0) {
+ error("%s: buffer error: %s", __func__, ssh_err(r));
+ goto send;
+ }
switch (type) {
case SSH_AGENT_CONSTRAIN_LIFETIME:
- if ((r = sshbuf_get_u32(e->request, &seconds)) != 0)
- fatal("%s: buffer error: %s",
+ if ((r = sshbuf_get_u32(e->request, &seconds)) != 0) {
+ error("%s: buffer error: %s",
__func__, ssh_err(r));
+ goto send;
+ }
death = monotime() + seconds;
break;
case SSH_AGENT_CONSTRAIN_CONFIRM:
confirm = 1;
break;
default:
- error("process_add_smartcard_key: "
- "Unknown constraint type %d", type);
+ error("%s: Unknown constraint type %d", __func__, type);
goto send;
}
}
+ if (realpath(provider, canonical_provider) == NULL) {
+ verbose("failed PKCS#11 add of \"%.100s\": realpath: %s",
+ provider, strerror(errno));
+ goto send;
+ }
+ if (match_pattern_list(canonical_provider, provider_whitelist, 0) != 1) {
+ verbose("refusing PKCS#11 add of \"%.100s\": "
+ "provider not whitelisted", canonical_provider);
+ goto send;
+ }
+ debug("%s: add %.100s", __func__, canonical_provider);
if (lifetime && !death)
death = monotime() + lifetime;
- count = pkcs11_add_provider(provider, pin, &keys);
+ count = pkcs11_add_provider(canonical_provider, pin, &keys, &comments);
for (i = 0; i < count; i++) {
k = keys[i];
- version = k->type == KEY_RSA1 ? 1 : 2;
- tab = idtab_lookup(version);
- if (lookup_identity(k, version) == NULL) {
+ if (lookup_identity(k) == NULL) {
id = xcalloc(1, sizeof(Identity));
id->key = k;
- id->provider = xstrdup(provider);
- id->comment = xstrdup(provider); /* XXX */
+ keys[i] = NULL; /* transferred */
+ id->provider = xstrdup(canonical_provider);
+ if (*comments[i] != '\0') {
+ id->comment = comments[i];
+ comments[i] = NULL; /* transferred */
+ } else {
+ id->comment = xstrdup(canonical_provider);
+ }
id->death = death;
id->confirm = confirm;
- TAILQ_INSERT_TAIL(&tab->idlist, id, next);
- tab->nentries++;
+ TAILQ_INSERT_TAIL(&idtab->idlist, id, next);
+ idtab->nentries++;
success = 1;
- } else {
- sshkey_free(k);
}
- keys[i] = NULL;
+ sshkey_free(keys[i]);
+ free(comments[i]);
}
send:
free(pin);
free(provider);
free(keys);
+ free(comments);
send_status(e, success);
}
static void
process_remove_smartcard_key(SocketEntry *e)
{
- char *provider = NULL, *pin = NULL;
- int r, version, success = 0;
+ char *provider = NULL, *pin = NULL, canonical_provider[PATH_MAX];
+ int r, success = 0;
Identity *id, *nxt;
- Idtab *tab;
if ((r = sshbuf_get_cstring(e->request, &provider, NULL)) != 0 ||
- (r = sshbuf_get_cstring(e->request, &pin, NULL)) != 0)
- fatal("%s: buffer error: %s", __func__, ssh_err(r));
+ (r = sshbuf_get_cstring(e->request, &pin, NULL)) != 0) {
+ error("%s: buffer error: %s", __func__, ssh_err(r));
+ goto send;
+ }
free(pin);
- for (version = 1; version < 3; version++) {
- tab = idtab_lookup(version);
- for (id = TAILQ_FIRST(&tab->idlist); id; id = nxt) {
- nxt = TAILQ_NEXT(id, next);
- /* Skip file--based keys */
- if (id->provider == NULL)
- continue;
- if (!strcmp(provider, id->provider)) {
- TAILQ_REMOVE(&tab->idlist, id, next);
- free_identity(id);
- tab->nentries--;
- }
+ if (realpath(provider, canonical_provider) == NULL) {
+ verbose("failed PKCS#11 add of \"%.100s\": realpath: %s",
+ provider, strerror(errno));
+ goto send;
+ }
+
+ debug("%s: remove %.100s", __func__, canonical_provider);
+ for (id = TAILQ_FIRST(&idtab->idlist); id; id = nxt) {
+ nxt = TAILQ_NEXT(id, next);
+ /* Skip file--based keys */
+ if (id->provider == NULL)
+ continue;
+ if (!strcmp(canonical_provider, id->provider)) {
+ TAILQ_REMOVE(&idtab->idlist, id, next);
+ free_identity(id);
+ idtab->nentries--;
}
}
- if (pkcs11_del_provider(provider) == 0)
+ if (pkcs11_del_provider(canonical_provider) == 0)
success = 1;
else
- error("process_remove_smartcard_key:"
- " pkcs11_del_provider failed");
+ error("%s: pkcs11_del_provider failed", __func__);
+send:
free(provider);
send_status(e, success);
}
@@ -804,88 +769,86 @@ process_remove_smartcard_key(SocketEntry *e)
/* dispatch incoming messages */
-static void
-process_message(SocketEntry *e)
+static int
+process_message(u_int socknum)
{
u_int msg_len;
u_char type;
const u_char *cp;
int r;
+ SocketEntry *e;
+
+ if (socknum >= sockets_alloc) {
+ fatal("%s: socket number %u >= allocated %u",
+ __func__, socknum, sockets_alloc);
+ }
+ e = &sockets[socknum];
if (sshbuf_len(e->input) < 5)
- return; /* Incomplete message. */
+ return 0; /* Incomplete message header. */
cp = sshbuf_ptr(e->input);
msg_len = PEEK_U32(cp);
- if (msg_len > 256 * 1024) {
- close_socket(e);
- return;
+ if (msg_len > AGENT_MAX_LEN) {
+ debug("%s: socket %u (fd=%d) message too long %u > %u",
+ __func__, socknum, e->fd, msg_len, AGENT_MAX_LEN);
+ return -1;
}
if (sshbuf_len(e->input) < msg_len + 4)
- return;
+ return 0; /* Incomplete message body. */
/* move the current input to e->request */
sshbuf_reset(e->request);
if ((r = sshbuf_get_stringb(e->input, e->request)) != 0 ||
- (r = sshbuf_get_u8(e->request, &type)) != 0)
+ (r = sshbuf_get_u8(e->request, &type)) != 0) {
+ if (r == SSH_ERR_MESSAGE_INCOMPLETE ||
+ r == SSH_ERR_STRING_TOO_LARGE) {
+ debug("%s: buffer error: %s", __func__, ssh_err(r));
+ return -1;
+ }
fatal("%s: buffer error: %s", __func__, ssh_err(r));
+ }
+
+ debug("%s: socket %u (fd=%d) type %d", __func__, socknum, e->fd, type);
- /* check wheter agent is locked */
+ /* check whether agent is locked */
if (locked && type != SSH_AGENTC_UNLOCK) {
sshbuf_reset(e->request);
switch (type) {
- case SSH_AGENTC_REQUEST_RSA_IDENTITIES:
case SSH2_AGENTC_REQUEST_IDENTITIES:
/* send empty lists */
- no_identities(e, type);
+ no_identities(e);
break;
default:
/* send a fail message for all other request types */
send_status(e, 0);
}
- return;
+ return 0;
}
- debug("type %d", type);
switch (type) {
case SSH_AGENTC_LOCK:
case SSH_AGENTC_UNLOCK:
process_lock_agent(e, type == SSH_AGENTC_LOCK);
break;
-#ifdef WITH_SSH1
- /* ssh1 */
- case SSH_AGENTC_RSA_CHALLENGE:
- process_authentication_challenge1(e);
- break;
- case SSH_AGENTC_REQUEST_RSA_IDENTITIES:
- process_request_identities(e, 1);
- break;
- case SSH_AGENTC_ADD_RSA_IDENTITY:
- case SSH_AGENTC_ADD_RSA_ID_CONSTRAINED:
- process_add_identity(e, 1);
- break;
- case SSH_AGENTC_REMOVE_RSA_IDENTITY:
- process_remove_identity(e, 1);
- break;
-#endif
case SSH_AGENTC_REMOVE_ALL_RSA_IDENTITIES:
- process_remove_all_identities(e, 1); /* safe for !WITH_SSH1 */
+ process_remove_all_identities(e); /* safe for !WITH_SSH1 */
break;
/* ssh2 */
case SSH2_AGENTC_SIGN_REQUEST:
process_sign_request2(e);
break;
case SSH2_AGENTC_REQUEST_IDENTITIES:
- process_request_identities(e, 2);
+ process_request_identities(e);
break;
case SSH2_AGENTC_ADD_IDENTITY:
case SSH2_AGENTC_ADD_ID_CONSTRAINED:
- process_add_identity(e, 2);
+ process_add_identity(e);
break;
case SSH2_AGENTC_REMOVE_IDENTITY:
- process_remove_identity(e, 2);
+ process_remove_identity(e);
break;
case SSH2_AGENTC_REMOVE_ALL_IDENTITIES:
- process_remove_all_identities(e, 2);
+ process_remove_all_identities(e);
break;
#ifdef ENABLE_PKCS11
case SSH_AGENTC_ADD_SMARTCARD_KEY:
@@ -903,6 +866,7 @@ process_message(SocketEntry *e)
send_status(e, 0);
break;
}
+ return 0;
}
static void
@@ -929,7 +893,7 @@ new_socket(sock_type type, int fd)
}
old_alloc = sockets_alloc;
new_alloc = sockets_alloc + 10;
- sockets = xrealloc(sockets, new_alloc, sizeof(sockets[0]));
+ sockets = xreallocarray(sockets, new_alloc, sizeof(sockets[0]));
for (i = old_alloc; i < new_alloc; i++)
sockets[i].type = AUTH_UNUSED;
sockets_alloc = new_alloc;
@@ -944,19 +908,153 @@ new_socket(sock_type type, int fd)
}
static int
-prepare_select(fd_set **fdrp, fd_set **fdwp, int *fdl, u_int *nallocp,
- struct timeval **tvpp)
+handle_socket_read(u_int socknum)
{
- u_int i, sz;
- int n = 0;
- static struct timeval tv;
+ struct sockaddr_un sunaddr;
+ socklen_t slen;
+ uid_t euid;
+ gid_t egid;
+ int fd;
+
+ slen = sizeof(sunaddr);
+ fd = accept(sockets[socknum].fd, (struct sockaddr *)&sunaddr, &slen);
+ if (fd == -1) {
+ error("accept from AUTH_SOCKET: %s", strerror(errno));
+ return -1;
+ }
+ if (getpeereid(fd, &euid, &egid) == -1) {
+ error("getpeereid %d failed: %s", fd, strerror(errno));
+ close(fd);
+ return -1;
+ }
+ if ((euid != 0) && (getuid() != euid)) {
+ error("uid mismatch: peer euid %u != uid %u",
+ (u_int) euid, (u_int) getuid());
+ close(fd);
+ return -1;
+ }
+ new_socket(AUTH_CONNECTION, fd);
+ return 0;
+}
+
+static int
+handle_conn_read(u_int socknum)
+{
+ char buf[AGENT_RBUF_LEN];
+ ssize_t len;
+ int r;
+
+ if ((len = read(sockets[socknum].fd, buf, sizeof(buf))) <= 0) {
+ if (len == -1) {
+ if (errno == EAGAIN || errno == EINTR)
+ return 0;
+ error("%s: read error on socket %u (fd %d): %s",
+ __func__, socknum, sockets[socknum].fd,
+ strerror(errno));
+ }
+ return -1;
+ }
+ if ((r = sshbuf_put(sockets[socknum].input, buf, len)) != 0)
+ fatal("%s: buffer error: %s", __func__, ssh_err(r));
+ explicit_bzero(buf, sizeof(buf));
+ process_message(socknum);
+ return 0;
+}
+
+static int
+handle_conn_write(u_int socknum)
+{
+ ssize_t len;
+ int r;
+
+ if (sshbuf_len(sockets[socknum].output) == 0)
+ return 0; /* shouldn't happen */
+ if ((len = write(sockets[socknum].fd,
+ sshbuf_ptr(sockets[socknum].output),
+ sshbuf_len(sockets[socknum].output))) <= 0) {
+ if (len == -1) {
+ if (errno == EAGAIN || errno == EINTR)
+ return 0;
+ error("%s: read error on socket %u (fd %d): %s",
+ __func__, socknum, sockets[socknum].fd,
+ strerror(errno));
+ }
+ return -1;
+ }
+ if ((r = sshbuf_consume(sockets[socknum].output, len)) != 0)
+ fatal("%s: buffer error: %s", __func__, ssh_err(r));
+ return 0;
+}
+
+static void
+after_poll(struct pollfd *pfd, size_t npfd, u_int maxfds)
+{
+ size_t i;
+ u_int socknum, activefds = npfd;
+
+ for (i = 0; i < npfd; i++) {
+ if (pfd[i].revents == 0)
+ continue;
+ /* Find sockets entry */
+ for (socknum = 0; socknum < sockets_alloc; socknum++) {
+ if (sockets[socknum].type != AUTH_SOCKET &&
+ sockets[socknum].type != AUTH_CONNECTION)
+ continue;
+ if (pfd[i].fd == sockets[socknum].fd)
+ break;
+ }
+ if (socknum >= sockets_alloc) {
+ error("%s: no socket for fd %d", __func__, pfd[i].fd);
+ continue;
+ }
+ /* Process events */
+ switch (sockets[socknum].type) {
+ case AUTH_SOCKET:
+ if ((pfd[i].revents & (POLLIN|POLLERR)) == 0)
+ break;
+ if (npfd > maxfds) {
+ debug3("out of fds (active %u >= limit %u); "
+ "skipping accept", activefds, maxfds);
+ break;
+ }
+ if (handle_socket_read(socknum) == 0)
+ activefds++;
+ break;
+ case AUTH_CONNECTION:
+ if ((pfd[i].revents & (POLLIN|POLLERR)) != 0 &&
+ handle_conn_read(socknum) != 0) {
+ goto close_sock;
+ }
+ if ((pfd[i].revents & (POLLOUT|POLLHUP)) != 0 &&
+ handle_conn_write(socknum) != 0) {
+ close_sock:
+ if (activefds == 0)
+ fatal("activefds == 0 at close_sock");
+ close_socket(&sockets[socknum]);
+ activefds--;
+ break;
+ }
+ break;
+ default:
+ break;
+ }
+ }
+}
+
+static int
+prepare_poll(struct pollfd **pfdp, size_t *npfdp, int *timeoutp, u_int maxfds)
+{
+ struct pollfd *pfd = *pfdp;
+ size_t i, j, npfd = 0;
time_t deadline;
+ int r;
+ /* Count active sockets */
for (i = 0; i < sockets_alloc; i++) {
switch (sockets[i].type) {
case AUTH_SOCKET:
case AUTH_CONNECTION:
- n = MAX(n, sockets[i].fd);
+ npfd++;
break;
case AUTH_UNUSED:
break;
@@ -965,28 +1063,44 @@ prepare_select(fd_set **fdrp, fd_set **fdwp, int *fdl, u_int *nallocp,
break;
}
}
+ if (npfd != *npfdp &&
+ (pfd = recallocarray(pfd, *npfdp, npfd, sizeof(*pfd))) == NULL)
+ fatal("%s: recallocarray failed", __func__);
+ *pfdp = pfd;
+ *npfdp = npfd;
- sz = howmany(n+1, NFDBITS) * sizeof(fd_mask);
- if (*fdrp == NULL || sz > *nallocp) {
- free(*fdrp);
- free(*fdwp);
- *fdrp = xmalloc(sz);
- *fdwp = xmalloc(sz);
- *nallocp = sz;
- }
- if (n < *fdl)
- debug("XXX shrink: %d < %d", n, *fdl);
- *fdl = n;
- memset(*fdrp, 0, sz);
- memset(*fdwp, 0, sz);
-
- for (i = 0; i < sockets_alloc; i++) {
+ for (i = j = 0; i < sockets_alloc; i++) {
switch (sockets[i].type) {
case AUTH_SOCKET:
+ if (npfd > maxfds) {
+ debug3("out of fds (active %zu >= limit %u); "
+ "skipping arming listener", npfd, maxfds);
+ break;
+ }
+ pfd[j].fd = sockets[i].fd;
+ pfd[j].revents = 0;
+ pfd[j].events = POLLIN;
+ j++;
+ break;
case AUTH_CONNECTION:
- FD_SET(sockets[i].fd, *fdrp);
+ pfd[j].fd = sockets[i].fd;
+ pfd[j].revents = 0;
+ /*
+ * Only prepare to read if we can handle a full-size
+ * input read buffer and enqueue a max size reply..
+ */
+ if ((r = sshbuf_check_reserve(sockets[i].input,
+ AGENT_RBUF_LEN)) == 0 &&
+ (r = sshbuf_check_reserve(sockets[i].output,
+ AGENT_MAX_LEN)) == 0)
+ pfd[j].events = POLLIN;
+ else if (r != SSH_ERR_NO_BUFFER_SPACE) {
+ fatal("%s: buffer error: %s",
+ __func__, ssh_err(r));
+ }
if (sshbuf_len(sockets[i].output) > 0)
- FD_SET(sockets[i].fd, *fdwp);
+ pfd[j].events |= POLLOUT;
+ j++;
break;
default:
break;
@@ -995,101 +1109,19 @@ prepare_select(fd_set **fdrp, fd_set **fdwp, int *fdl, u_int *nallocp,
deadline = reaper();
if (parent_alive_interval != 0)
deadline = (deadline == 0) ? parent_alive_interval :
- MIN(deadline, parent_alive_interval);
+ MINIMUM(deadline, parent_alive_interval);
if (deadline == 0) {
- *tvpp = NULL;
+ *timeoutp = -1; /* INFTIM */
} else {
- tv.tv_sec = deadline;
- tv.tv_usec = 0;
- *tvpp = &tv;
+ if (deadline > INT_MAX / 1000)
+ *timeoutp = INT_MAX / 1000;
+ else
+ *timeoutp = deadline * 1000;
}
return (1);
}
static void
-after_select(fd_set *readset, fd_set *writeset)
-{
- struct sockaddr_un sunaddr;
- socklen_t slen;
- char buf[1024];
- int len, sock, r;
- u_int i, orig_alloc;
- uid_t euid;
- gid_t egid;
-
- for (i = 0, orig_alloc = sockets_alloc; i < orig_alloc; i++)
- switch (sockets[i].type) {
- case AUTH_UNUSED:
- break;
- case AUTH_SOCKET:
- if (FD_ISSET(sockets[i].fd, readset)) {
- slen = sizeof(sunaddr);
- sock = accept(sockets[i].fd,
- (struct sockaddr *)&sunaddr, &slen);
- if (sock < 0) {
- error("accept from AUTH_SOCKET: %s",
- strerror(errno));
- break;
- }
- if (getpeereid(sock, &euid, &egid) < 0) {
- error("getpeereid %d failed: %s",
- sock, strerror(errno));
- close(sock);
- break;
- }
- if ((euid != 0) && (getuid() != euid)) {
- error("uid mismatch: "
- "peer euid %u != uid %u",
- (u_int) euid, (u_int) getuid());
- close(sock);
- break;
- }
- new_socket(AUTH_CONNECTION, sock);
- }
- break;
- case AUTH_CONNECTION:
- if (sshbuf_len(sockets[i].output) > 0 &&
- FD_ISSET(sockets[i].fd, writeset)) {
- len = write(sockets[i].fd,
- sshbuf_ptr(sockets[i].output),
- sshbuf_len(sockets[i].output));
- if (len == -1 && (errno == EAGAIN ||
- errno == EWOULDBLOCK ||
- errno == EINTR))
- continue;
- if (len <= 0) {
- close_socket(&sockets[i]);
- break;
- }
- if ((r = sshbuf_consume(sockets[i].output,
- len)) != 0)
- fatal("%s: buffer error: %s",
- __func__, ssh_err(r));
- }
- if (FD_ISSET(sockets[i].fd, readset)) {
- len = read(sockets[i].fd, buf, sizeof(buf));
- if (len == -1 && (errno == EAGAIN ||
- errno == EWOULDBLOCK ||
- errno == EINTR))
- continue;
- if (len <= 0) {
- close_socket(&sockets[i]);
- break;
- }
- if ((r = sshbuf_put(sockets[i].input,
- buf, len)) != 0)
- fatal("%s: buffer error: %s",
- __func__, ssh_err(r));
- explicit_bzero(buf, sizeof(buf));
- process_message(&sockets[i]);
- }
- break;
- default:
- fatal("Unknown type %d", sockets[i].type);
- }
-}
-
-static void
cleanup_socket(void)
{
if (cleanup_pid != 0 && getpid() != cleanup_pid)
@@ -1137,8 +1169,8 @@ static void
usage(void)
{
fprintf(stderr,
- "usage: ssh-agent [-c | -s] [-d] [-a bind_address] [-E fingerprint_hash]\n"
- " [-t life] [command [arg ...]]\n"
+ "usage: ssh-agent [-c | -s] [-Dd] [-a bind_address] [-E fingerprint_hash]\n"
+ " [-P provider_whitelist] [-t life] [command [arg ...]]\n"
" ssh-agent [-c | -s] -k\n");
exit(1);
}
@@ -1146,11 +1178,9 @@ usage(void)
int
main(int ac, char **av)
{
- int c_flag = 0, d_flag = 0, k_flag = 0, s_flag = 0;
+ int c_flag = 0, d_flag = 0, D_flag = 0, k_flag = 0, s_flag = 0;
int sock, fd, ch, result, saved_errno;
- u_int nalloc;
char *shell, *format, *pidstr, *agentsocket = NULL;
- fd_set *readsetp = NULL, *writesetp = NULL;
#ifdef HAVE_SETRLIMIT
struct rlimit rlim;
#endif
@@ -1158,9 +1188,12 @@ main(int ac, char **av)
extern char *optarg;
pid_t pid;
char pidstrbuf[1 + 3 * sizeof pid];
- struct timeval *tvp = NULL;
size_t len;
mode_t prev_mask;
+ int timeout = -1; /* INFTIM */
+ struct pollfd *pfd = NULL;
+ size_t npfd = 0;
+ u_int maxfds;
/* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */
sanitise_stdfd();
@@ -1169,19 +1202,17 @@ main(int ac, char **av)
setegid(getgid());
setgid(getgid());
-#if defined(HAVE_PRCTL) && defined(PR_SET_DUMPABLE)
- /* Disable ptrace on Linux without sgid bit */
- prctl(PR_SET_DUMPABLE, 0);
-#endif
+ platform_disable_tracing(0); /* strict=no */
-#ifdef WITH_OPENSSL
- OpenSSL_add_all_algorithms();
+#ifdef RLIMIT_NOFILE
+ if (getrlimit(RLIMIT_NOFILE, &rlim) == -1)
+ fatal("%s: getrlimit: %s", __progname, strerror(errno));
#endif
__progname = ssh_get_progname(av[0]);
seed_rng();
- while ((ch = getopt(ac, av, "cdksE:a:t:")) != -1) {
+ while ((ch = getopt(ac, av, "cDdksE:a:P:t:")) != -1) {
switch (ch) {
case 'E':
fingerprint_hash = ssh_digest_alg_by_name(optarg);
@@ -1196,16 +1227,26 @@ main(int ac, char **av)
case 'k':
k_flag++;
break;
+ case 'P':
+ if (provider_whitelist != NULL)
+ fatal("-P option already specified");
+ provider_whitelist = xstrdup(optarg);
+ break;
case 's':
if (c_flag)
usage();
s_flag++;
break;
case 'd':
- if (d_flag)
+ if (d_flag || D_flag)
usage();
d_flag++;
break;
+ case 'D':
+ if (d_flag || D_flag)
+ usage();
+ D_flag++;
+ break;
case 'a':
agentsocket = optarg;
break;
@@ -1222,9 +1263,12 @@ main(int ac, char **av)
ac -= optind;
av += optind;
- if (ac > 0 && (c_flag || k_flag || s_flag || d_flag))
+ if (ac > 0 && (c_flag || k_flag || s_flag || d_flag || D_flag))
usage();
+ if (provider_whitelist == NULL)
+ provider_whitelist = xstrdup(DEFAULT_PROVIDER_WHITELIST);
+
if (ac == 0 && !c_flag && !s_flag) {
shell = getenv("SHELL");
if (shell != NULL && (len = strlen(shell)) > 2 &&
@@ -1257,6 +1301,18 @@ main(int ac, char **av)
printf("echo Agent pid %ld killed;\n", (long)pid);
exit(0);
}
+
+ /*
+ * Minimum file descriptors:
+ * stdio (3) + listener (1) + syslog (1 maybe) + connection (1) +
+ * a few spare for libc / stack protectors / sanitisers, etc.
+ */
+#define SSH_AGENT_MIN_FDS (3+1+1+1+4)
+ if (rlim.rlim_cur < SSH_AGENT_MIN_FDS)
+ fatal("%s: file descriptor rlimit %lld too low (minimum %u)",
+ __progname, (long long)rlim.rlim_cur, SSH_AGENT_MIN_FDS);
+ maxfds = rlim.rlim_cur - SSH_AGENT_MIN_FDS;
+
parent_pid = getpid();
if (agentsocket == NULL) {
@@ -1291,12 +1347,15 @@ main(int ac, char **av)
* Fork, and have the parent execute the command, if any, or present
* the socket data. The child continues as the authentication agent.
*/
- if (d_flag) {
- log_init(__progname, SYSLOG_LEVEL_DEBUG1, SYSLOG_FACILITY_AUTH, 1);
+ if (D_flag || d_flag) {
+ log_init(__progname,
+ d_flag ? SYSLOG_LEVEL_DEBUG3 : SYSLOG_LEVEL_INFO,
+ SYSLOG_FACILITY_AUTH, 1);
format = c_flag ? "setenv %s %s;\n" : "%s=%s; export %s;\n";
printf(format, SSH_AUTHSOCKET_ENV_NAME, socket_name,
SSH_AUTHSOCKET_ENV_NAME);
printf("echo Agent pid %ld;\n", (long)parent_pid);
+ fflush(stdout);
goto skip;
}
pid = fork();
@@ -1346,7 +1405,7 @@ main(int ac, char **av)
#ifdef HAVE_SETRLIMIT
/* deny core dumps, since memory contains unencrypted private keys */
rlim.rlim_cur = rlim.rlim_max = 0;
- if (setrlimit(RLIMIT_CORE, &rlim) < 0) {
+ if (setrlimit(RLIMIT_CORE, &rlim) == -1) {
error("setrlimit RLIMIT_CORE: %s", strerror(errno));
cleanup_exit(1);
}
@@ -1363,25 +1422,28 @@ skip:
if (ac > 0)
parent_alive_interval = 10;
idtab_init();
- signal(SIGPIPE, SIG_IGN);
- signal(SIGINT, d_flag ? cleanup_handler : SIG_IGN);
- signal(SIGHUP, cleanup_handler);
- signal(SIGTERM, cleanup_handler);
- nalloc = 0;
+ ssh_signal(SIGPIPE, SIG_IGN);
+ ssh_signal(SIGINT, (d_flag | D_flag) ? cleanup_handler : SIG_IGN);
+ ssh_signal(SIGHUP, cleanup_handler);
+ ssh_signal(SIGTERM, cleanup_handler);
+
+ if (pledge("stdio rpath cpath unix id proc exec", NULL) == -1)
+ fatal("%s: pledge: %s", __progname, strerror(errno));
+ platform_pledge_agent();
while (1) {
- prepare_select(&readsetp, &writesetp, &max_fd, &nalloc, &tvp);
- result = select(max_fd + 1, readsetp, writesetp, NULL, tvp);
+ prepare_poll(&pfd, &npfd, &timeout, maxfds);
+ result = poll(pfd, npfd, timeout);
saved_errno = errno;
if (parent_alive_interval != 0)
check_parent_exists();
(void) reaper(); /* remove expired keys */
- if (result < 0) {
+ if (result == -1) {
if (saved_errno == EINTR)
continue;
- fatal("select: %s", strerror(saved_errno));
+ fatal("poll: %s", strerror(saved_errno));
} else if (result > 0)
- after_select(readsetp, writesetp);
+ after_poll(pfd, npfd, maxfds);
}
/* NOTREACHED */
}
generated by cgit v1.2.3 (git 2.25.1) at 2025-10-03 06:39:36 +0000