1 files changed, 128 insertions, 452 deletions

diff --git a/auth2-pubkey.c b/auth2-pubkey.c
index 3e5706f4dbef..169839b01ed7 100644
--- a/auth2-pubkey.c
+++ b/auth2-pubkey.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: auth2-pubkey.c,v 1.62 2017/01/30 01:03:00 djm Exp $ */
+/* $OpenBSD: auth2-pubkey.c,v 1.71 2017/09/07 23:48:09 djm Exp $ */
 /*
  * Copyright (c) 2000 Markus Friedl.  All rights reserved.
  *
@@ -27,7 +27,6 @@
 
 #include <sys/types.h>
 #include <sys/stat.h>
-#include <sys/wait.h>
 
 #include <errno.h>
 #include <fcntl.h>
@@ -52,7 +51,7 @@
 #include "misc.h"
 #include "servconf.h"
 #include "compat.h"
-#include "key.h"
+#include "sshkey.h"
 #include "hostfile.h"
 #include "auth.h"
 #include "pathnames.h"
@@ -75,42 +74,52 @@ extern u_char *session_id2;
 extern u_int session_id2_len;
 
 static int
-userauth_pubkey(Authctxt *authctxt)
+userauth_pubkey(struct ssh *ssh)
 {
-	Buffer b;
-	Key *key = NULL;
-	char *pkalg, *userstyle, *fp = NULL;
-	u_char *pkblob, *sig;
-	u_int alen, blen, slen;
-	int have_sig, pktype;
+	Authctxt *authctxt = ssh->authctxt;
+	struct sshbuf *b;
+	struct sshkey *key = NULL;
+	char *pkalg, *userstyle = NULL, *fp = NULL;
+	u_char *pkblob, *sig, have_sig;
+	size_t blen, slen;
+	int r, pktype;
 	int authenticated = 0;
 
 	if (!authctxt->valid) {
 		debug2("%s: disabled because of invalid user", __func__);
 		return 0;
 	}
-	have_sig = packet_get_char();
-	if (datafellows & SSH_BUG_PKAUTH) {
+	if ((r = sshpkt_get_u8(ssh, &have_sig)) != 0)
+		fatal("%s: sshpkt_get_u8 failed: %s", __func__, ssh_err(r));
+	if (ssh->compat & SSH_BUG_PKAUTH) {
 		debug2("%s: SSH_BUG_PKAUTH", __func__);
+		if ((b = sshbuf_new()) == NULL)
+			fatal("%s: sshbuf_new failed", __func__);
 		/* no explicit pkalg given */
-		pkblob = packet_get_string(&blen);
-		buffer_init(&b);
-		buffer_append(&b, pkblob, blen);
 		/* so we have to extract the pkalg from the pkblob */
-		pkalg = buffer_get_string(&b, &alen);
-		buffer_free(&b);
+		/* XXX use sshbuf_from() */
+		if ((r = sshpkt_get_string(ssh, &pkblob, &blen)) != 0 ||
+		    (r = sshbuf_put(b, pkblob, blen)) != 0 ||
+		    (r = sshbuf_get_cstring(b, &pkalg, NULL)) != 0)
+			fatal("%s: failed: %s", __func__, ssh_err(r));
+		sshbuf_free(b);
 	} else {
-		pkalg = packet_get_string(&alen);
-		pkblob = packet_get_string(&blen);
+		if ((r = sshpkt_get_cstring(ssh, &pkalg, NULL)) != 0 ||
+		    (r = sshpkt_get_string(ssh, &pkblob, &blen)) != 0)
+			fatal("%s: sshpkt_get_cstring failed: %s",
+			    __func__, ssh_err(r));
 	}
-	pktype = key_type_from_name(pkalg);
+	pktype = sshkey_type_from_name(pkalg);
 	if (pktype == KEY_UNSPEC) {
 		/* this is perfectly legal */
 		logit("%s: unsupported public key algorithm: %s",
 		    __func__, pkalg);
 		goto done;
 	}
-	key = key_from_blob(pkblob, blen);
+	if ((r = sshkey_from_blob(pkblob, blen, &key)) != 0) {
+		error("%s: could not parse key: %s", __func__, ssh_err(r));
+		goto done;
+	}
 	if (key == NULL) {
 		error("%s: cannot decode key: %s", __func__, pkalg);
 		goto done;
@@ -120,15 +129,15 @@ userauth_pubkey(Authctxt *authctxt)
 		    "(received %d, expected %d)", __func__, key->type, pktype);
 		goto done;
 	}
-	if (key_type_plain(key->type) == KEY_RSA &&
-	    (datafellows & SSH_BUG_RSASIGMD5) != 0) {
+	if (sshkey_type_plain(key->type) == KEY_RSA &&
+	    (ssh->compat & SSH_BUG_RSASIGMD5) != 0) {
 		logit("Refusing RSA key because client uses unsafe "
 		    "signature scheme");
 		goto done;
 	}
 	fp = sshkey_fingerprint(key, options.fingerprint_hash, SSH_FP_DEFAULT);
-	if (auth2_userkey_already_used(authctxt, key)) {
-		logit("refusing previously-used %s key", key_type(key));
+	if (auth2_key_already_used(authctxt, key)) {
+		logit("refusing previously-used %s key", sshkey_type(key));
 		goto done;
 	}
 	if (match_pattern_list(sshkey_ssh_name(key),
@@ -141,54 +150,65 @@ userauth_pubkey(Authctxt *authctxt)
 	if (have_sig) {
 		debug3("%s: have signature for %s %s",
 		    __func__, sshkey_type(key), fp);
-		sig = packet_get_string(&slen);
-		packet_check_eom();
-		buffer_init(&b);
-		if (datafellows & SSH_OLD_SESSIONID) {
-			buffer_append(&b, session_id2, session_id2_len);
+		if ((r = sshpkt_get_string(ssh, &sig, &slen)) != 0 ||
+		    (r = sshpkt_get_end(ssh)) != 0)
+			fatal("%s: %s", __func__, ssh_err(r));
+		if ((b = sshbuf_new()) == NULL)
+			fatal("%s: sshbuf_new failed", __func__);
+		if (ssh->compat & SSH_OLD_SESSIONID) {
+			if ((r = sshbuf_put(b, session_id2,
+			    session_id2_len)) != 0)
+				fatal("%s: sshbuf_put session id: %s",
+				    __func__, ssh_err(r));
 		} else {
-			buffer_put_string(&b, session_id2, session_id2_len);
+			if ((r = sshbuf_put_string(b, session_id2,
+			    session_id2_len)) != 0)
+				fatal("%s: sshbuf_put_string session id: %s",
+				    __func__, ssh_err(r));
 		}
 		/* reconstruct packet */
-		buffer_put_char(&b, SSH2_MSG_USERAUTH_REQUEST);
 		xasprintf(&userstyle, "%s%s%s", authctxt->user,
 		    authctxt->style ? ":" : "",
 		    authctxt->style ? authctxt->style : "");
-		buffer_put_cstring(&b, userstyle);
-		free(userstyle);
-		buffer_put_cstring(&b,
-		    datafellows & SSH_BUG_PKSERVICE ?
-		    "ssh-userauth" :
-		    authctxt->service);
-		if (datafellows & SSH_BUG_PKAUTH) {
-			buffer_put_char(&b, have_sig);
+		if ((r = sshbuf_put_u8(b, SSH2_MSG_USERAUTH_REQUEST)) != 0 ||
+		    (r = sshbuf_put_cstring(b, userstyle)) != 0 ||
+		    (r = sshbuf_put_cstring(b, ssh->compat & SSH_BUG_PKSERVICE ?
+		    "ssh-userauth" : authctxt->service)) != 0)
+			fatal("%s: build packet failed: %s",
+			    __func__, ssh_err(r));
+		if (ssh->compat & SSH_BUG_PKAUTH) {
+			if ((r = sshbuf_put_u8(b, have_sig)) != 0)
+				fatal("%s: build packet failed: %s",
+				    __func__, ssh_err(r));
 		} else {
-			buffer_put_cstring(&b, "publickey");
-			buffer_put_char(&b, have_sig);
-			buffer_put_cstring(&b, pkalg);
+			if ((r = sshbuf_put_cstring(b, "publickey")) != 0 ||
+			    (r = sshbuf_put_u8(b, have_sig)) != 0 ||
+			    (r = sshbuf_put_cstring(b, pkalg) != 0))
+				fatal("%s: build packet failed: %s",
+				    __func__, ssh_err(r));
 		}
-		buffer_put_string(&b, pkblob, blen);
+		if ((r = sshbuf_put_string(b, pkblob, blen)) != 0)
+			fatal("%s: build packet failed: %s",
+			    __func__, ssh_err(r));
 #ifdef DEBUG_PK
-		buffer_dump(&b);
+		sshbuf_dump(b, stderr);
 #endif
-		pubkey_auth_info(authctxt, key, NULL);
 
 		/* test for correct signature */
 		authenticated = 0;
 		if (PRIVSEP(user_key_allowed(authctxt->pw, key, 1)) &&
-		    PRIVSEP(key_verify(key, sig, slen, buffer_ptr(&b),
-		    buffer_len(&b))) == 1) {
+		    PRIVSEP(sshkey_verify(key, sig, slen, sshbuf_ptr(b),
+		    sshbuf_len(b), ssh->compat)) == 0) {
 			authenticated = 1;
-			/* Record the successful key to prevent reuse */
-			auth2_record_userkey(authctxt, key);
-			key = NULL; /* Don't free below */
 		}
-		buffer_free(&b);
+		sshbuf_free(b);
 		free(sig);
+		auth2_record_key(authctxt, authenticated, key);
 	} else {
 		debug("%s: test whether pkalg/pkblob are acceptable for %s %s",
 		    __func__, sshkey_type(key), fp);
-		packet_check_eom();
+		if ((r = sshpkt_get_end(ssh)) != 0)
+			fatal("%s: %s", __func__, ssh_err(r));
 
 		/* XXX fake reply and always send PK_OK ? */
 		/*
@@ -199,11 +219,13 @@ userauth_pubkey(Authctxt *authctxt)
 		 * issue? -markus
 		 */
 		if (PRIVSEP(user_key_allowed(authctxt->pw, key, 0))) {
-			packet_start(SSH2_MSG_USERAUTH_PK_OK);
-			packet_put_string(pkalg, alen);
-			packet_put_string(pkblob, blen);
-			packet_send();
-			packet_write_wait();
+			if ((r = sshpkt_start(ssh, SSH2_MSG_USERAUTH_PK_OK))
+			    != 0 ||
+			    (r = sshpkt_put_cstring(ssh, pkalg)) != 0 ||
+			    (r = sshpkt_put_string(ssh, pkblob, blen)) != 0 ||
+			    (r = sshpkt_send(ssh)) != 0)
+				fatal("%s: %s", __func__, ssh_err(r));
+			ssh_packet_write_wait(ssh);
 			authctxt->postponed = 1;
 		}
 	}
@@ -211,333 +233,14 @@ userauth_pubkey(Authctxt *authctxt)
 		auth_clear_options();
 done:
 	debug2("%s: authenticated %d pkalg %s", __func__, authenticated, pkalg);
-	if (key != NULL)
-		key_free(key);
+	sshkey_free(key);
+	free(userstyle);
 	free(pkalg);
 	free(pkblob);
 	free(fp);
 	return authenticated;
 }
 
-void
-pubkey_auth_info(Authctxt *authctxt, const Key *key, const char *fmt, ...)
-{
-	char *fp, *extra;
-	va_list ap;
-	int i;
-
-	extra = NULL;
-	if (fmt != NULL) {
-		va_start(ap, fmt);
-		i = vasprintf(&extra, fmt, ap);
-		va_end(ap);
-		if (i < 0 || extra == NULL)
-			fatal("%s: vasprintf failed", __func__);	
-	}
-
-	if (key_is_cert(key)) {
-		fp = sshkey_fingerprint(key->cert->signature_key,
-		    options.fingerprint_hash, SSH_FP_DEFAULT);
-		auth_info(authctxt, "%s ID %s (serial %llu) CA %s %s%s%s", 
-		    key_type(key), key->cert->key_id,
-		    (unsigned long long)key->cert->serial,
-		    key_type(key->cert->signature_key),
-		    fp == NULL ? "(null)" : fp,
-		    extra == NULL ? "" : ", ", extra == NULL ? "" : extra);
-		free(fp);
-	} else {
-		fp = sshkey_fingerprint(key, options.fingerprint_hash,
-		    SSH_FP_DEFAULT);
-		auth_info(authctxt, "%s %s%s%s", key_type(key),
-		    fp == NULL ? "(null)" : fp,
-		    extra == NULL ? "" : ", ", extra == NULL ? "" : extra);
-		free(fp);
-	}
-	free(extra);
-}
-
-/*
- * Splits 's' into an argument vector. Handles quoted string and basic
- * escape characters (\\, \", \'). Caller must free the argument vector
- * and its members.
- */
-static int
-split_argv(const char *s, int *argcp, char ***argvp)
-{
-	int r = SSH_ERR_INTERNAL_ERROR;
-	int argc = 0, quote, i, j;
-	char *arg, **argv = xcalloc(1, sizeof(*argv));
-
-	*argvp = NULL;
-	*argcp = 0;
-
-	for (i = 0; s[i] != '\0'; i++) {
-		/* Skip leading whitespace */
-		if (s[i] == ' ' || s[i] == '\t')
-			continue;
-
-		/* Start of a token */
-		quote = 0;
-		if (s[i] == '\\' &&
-		    (s[i + 1] == '\'' || s[i + 1] == '\"' || s[i + 1] == '\\'))
-			i++;
-		else if (s[i] == '\'' || s[i] == '"')
-			quote = s[i++];
-
-		argv = xreallocarray(argv, (argc + 2), sizeof(*argv));
-		arg = argv[argc++] = xcalloc(1, strlen(s + i) + 1);
-		argv[argc] = NULL;
-
-		/* Copy the token in, removing escapes */
-		for (j = 0; s[i] != '\0'; i++) {
-			if (s[i] == '\\') {
-				if (s[i + 1] == '\'' ||
-				    s[i + 1] == '\"' ||
-				    s[i + 1] == '\\') {
-					i++; /* Skip '\' */
-					arg[j++] = s[i];
-				} else {
-					/* Unrecognised escape */
-					arg[j++] = s[i];
-				}
-			} else if (quote == 0 && (s[i] == ' ' || s[i] == '\t'))
-				break; /* done */
-			else if (quote != 0 && s[i] == quote)
-				break; /* done */
-			else
-				arg[j++] = s[i];
-		}
-		if (s[i] == '\0') {
-			if (quote != 0) {
-				/* Ran out of string looking for close quote */
-				r = SSH_ERR_INVALID_FORMAT;
-				goto out;
-			}
-			break;
-		}
-	}
-	/* Success */
-	*argcp = argc;
-	*argvp = argv;
-	argc = 0;
-	argv = NULL;
-	r = 0;
- out:
-	if (argc != 0 && argv != NULL) {
-		for (i = 0; i < argc; i++)
-			free(argv[i]);
-		free(argv);
-	}
-	return r;
-}
-
-/*
- * Reassemble an argument vector into a string, quoting and escaping as
- * necessary. Caller must free returned string.
- */
-static char *
-assemble_argv(int argc, char **argv)
-{
-	int i, j, ws, r;
-	char c, *ret;
-	struct sshbuf *buf, *arg;
-
-	if ((buf = sshbuf_new()) == NULL || (arg = sshbuf_new()) == NULL)
-		fatal("%s: sshbuf_new failed", __func__);
-
-	for (i = 0; i < argc; i++) {
-		ws = 0;
-		sshbuf_reset(arg);
-		for (j = 0; argv[i][j] != '\0'; j++) {
-			r = 0;
-			c = argv[i][j];
-			switch (c) {
-			case ' ':
-			case '\t':
-				ws = 1;
-				r = sshbuf_put_u8(arg, c);
-				break;
-			case '\\':
-			case '\'':
-			case '"':
-				if ((r = sshbuf_put_u8(arg, '\\')) != 0)
-					break;
-				/* FALLTHROUGH */
-			default:
-				r = sshbuf_put_u8(arg, c);
-				break;
-			}
-			if (r != 0)
-				fatal("%s: sshbuf_put_u8: %s",
-				    __func__, ssh_err(r));
-		}
-		if ((i != 0 && (r = sshbuf_put_u8(buf, ' ')) != 0) ||
-		    (ws != 0 && (r = sshbuf_put_u8(buf, '"')) != 0) ||
-		    (r = sshbuf_putb(buf, arg)) != 0 ||
-		    (ws != 0 && (r = sshbuf_put_u8(buf, '"')) != 0))
-			fatal("%s: buffer error: %s", __func__, ssh_err(r));
-	}
-	if ((ret = malloc(sshbuf_len(buf) + 1)) == NULL)
-		fatal("%s: malloc failed", __func__);
-	memcpy(ret, sshbuf_ptr(buf), sshbuf_len(buf));
-	ret[sshbuf_len(buf)] = '\0';
-	sshbuf_free(buf);
-	sshbuf_free(arg);
-	return ret;
-}
-
-/*
- * Runs command in a subprocess. Returns pid on success and a FILE* to the
- * subprocess' stdout or 0 on failure.
- * NB. "command" is only used for logging.
- */
-static pid_t
-subprocess(const char *tag, struct passwd *pw, const char *command,
-    int ac, char **av, FILE **child)
-{
-	FILE *f;
-	struct stat st;
-	int devnull, p[2], i;
-	pid_t pid;
-	char *cp, errmsg[512];
-	u_int envsize;
-	char **child_env;
-
-	*child = NULL;
-
-	debug3("%s: %s command \"%s\" running as %s", __func__,
-	    tag, command, pw->pw_name);
-
-	/* Verify the path exists and is safe-ish to execute */
-	if (*av[0] != '/') {
-		error("%s path is not absolute", tag);
-		return 0;
-	}
-	temporarily_use_uid(pw);
-	if (stat(av[0], &st) < 0) {
-		error("Could not stat %s \"%s\": %s", tag,
-		    av[0], strerror(errno));
-		restore_uid();
-		return 0;
-	}
-	if (auth_secure_path(av[0], &st, NULL, 0,
-	    errmsg, sizeof(errmsg)) != 0) {
-		error("Unsafe %s \"%s\": %s", tag, av[0], errmsg);
-		restore_uid();
-		return 0;
-	}
-
-	/*
-	 * Run the command; stderr is left in place, stdout is the
-	 * authorized_keys output.
-	 */
-	if (pipe(p) != 0) {
-		error("%s: pipe: %s", tag, strerror(errno));
-		restore_uid();
-		return 0;
-	}
-
-	/*
-	 * Don't want to call this in the child, where it can fatal() and
-	 * run cleanup_exit() code.
-	 */
-	restore_uid();
-
-	switch ((pid = fork())) {
-	case -1: /* error */
-		error("%s: fork: %s", tag, strerror(errno));
-		close(p[0]);
-		close(p[1]);
-		return 0;
-	case 0: /* child */
-		/* Prepare a minimal environment for the child. */
-		envsize = 5;
-		child_env = xcalloc(sizeof(*child_env), envsize);
-		child_set_env(&child_env, &envsize, "PATH", _PATH_STDPATH);
-		child_set_env(&child_env, &envsize, "USER", pw->pw_name);
-		child_set_env(&child_env, &envsize, "LOGNAME", pw->pw_name);
-		child_set_env(&child_env, &envsize, "HOME", pw->pw_dir);
-		if ((cp = getenv("LANG")) != NULL)
-			child_set_env(&child_env, &envsize, "LANG", cp);
-
-		for (i = 0; i < NSIG; i++)
-			signal(i, SIG_DFL);
-
-		if ((devnull = open(_PATH_DEVNULL, O_RDWR)) == -1) {
-			error("%s: open %s: %s", tag, _PATH_DEVNULL,
-			    strerror(errno));
-			_exit(1);
-		}
-		/* Keep stderr around a while longer to catch errors */
-		if (dup2(devnull, STDIN_FILENO) == -1 ||
-		    dup2(p[1], STDOUT_FILENO) == -1) {
-			error("%s: dup2: %s", tag, strerror(errno));
-			_exit(1);
-		}
-		closefrom(STDERR_FILENO + 1);
-
-		/* Don't use permanently_set_uid() here to avoid fatal() */
-		if (setresgid(pw->pw_gid, pw->pw_gid, pw->pw_gid) != 0) {
-			error("%s: setresgid %u: %s", tag, (u_int)pw->pw_gid,
-			    strerror(errno));
-			_exit(1);
-		}
-		if (setresuid(pw->pw_uid, pw->pw_uid, pw->pw_uid) != 0) {
-			error("%s: setresuid %u: %s", tag, (u_int)pw->pw_uid,
-			    strerror(errno));
-			_exit(1);
-		}
-		/* stdin is pointed to /dev/null at this point */
-		if (dup2(STDIN_FILENO, STDERR_FILENO) == -1) {
-			error("%s: dup2: %s", tag, strerror(errno));
-			_exit(1);
-		}
-
-		execve(av[0], av, child_env);
-		error("%s exec \"%s\": %s", tag, command, strerror(errno));
-		_exit(127);
-	default: /* parent */
-		break;
-	}
-
-	close(p[1]);
-	if ((f = fdopen(p[0], "r")) == NULL) {
-		error("%s: fdopen: %s", tag, strerror(errno));
-		close(p[0]);
-		/* Don't leave zombie child */
-		kill(pid, SIGTERM);
-		while (waitpid(pid, NULL, 0) == -1 && errno == EINTR)
-			;
-		return 0;
-	}
-	/* Success */
-	debug3("%s: %s pid %ld", __func__, tag, (long)pid);
-	*child = f;
-	return pid;
-}
-
-/* Returns 0 if pid exited cleanly, non-zero otherwise */
-static int
-exited_cleanly(pid_t pid, const char *tag, const char *cmd)
-{
-	int status;
-
-	while (waitpid(pid, &status, 0) == -1) {
-		if (errno != EINTR) {
-			error("%s: waitpid: %s", tag, strerror(errno));
-			return -1;
-		}
-	}
-	if (WIFSIGNALED(status)) {
-		error("%s %s exited on signal %d", tag, cmd, WTERMSIG(status));
-		return -1;
-	} else if (WEXITSTATUS(status) != 0) {
-		error("%s %s failed, status %d", tag, cmd, WEXITSTATUS(status));
-		return -1;
-	}
-	return 0;
-}
-
 static int
 match_principals_option(const char *principal_list, struct sshkey_cert *cert)
 {
@@ -559,7 +262,7 @@ match_principals_option(const char *principal_list, struct sshkey_cert *cert)
 }
 
 static int
-process_principals(FILE *f, char *file, struct passwd *pw,
+process_principals(FILE *f, const char *file, struct passwd *pw,
     const struct sshkey_cert *cert)
 {
 	char line[SSH_MAX_PUBKEY_BYTES], *cp, *ep, *line_opts;
@@ -597,8 +300,7 @@ process_principals(FILE *f, char *file, struct passwd *pw,
 		for (i = 0; i < cert->nprincipals; i++) {
 			if (strcmp(cp, cert->principals[i]) == 0) {
 				debug3("%s:%lu: matched principal \"%.100s\"",
-				    file == NULL ? "(command)" : file,
-				    linenum, cert->principals[i]);
+				    file, linenum, cert->principals[i]);
 				if (auth_parse_options(pw, line_opts,
 				    file, linenum) != 1)
 					continue;
@@ -671,7 +373,7 @@ match_principals_command(struct passwd *user_pw, const struct sshkey *key)
 	}
 
 	/* Turn the command into an argument vector */
-	if (split_argv(options.authorized_principals_command, &ac, &av) != 0) {
+	if (argv_split(options.authorized_principals_command, &ac, &av) != 0) {
 		error("AuthorizedPrincipalsCommand \"%s\" contains "
 		    "invalid quotes", command);
 		goto out;
@@ -720,21 +422,22 @@ match_principals_command(struct passwd *user_pw, const struct sshkey *key)
 		av[i] = tmp;
 	}
 	/* Prepare a printable command for logs, etc. */
-	command = assemble_argv(ac, av);
+	command = argv_assemble(ac, av);
 
 	if ((pid = subprocess("AuthorizedPrincipalsCommand", pw, command,
-	    ac, av, &f)) == 0)
+	    ac, av, &f,
+	    SSH_SUBPROCESS_STDOUT_CAPTURE|SSH_SUBPROCESS_STDERR_DISCARD)) == 0)
 		goto out;
 
 	uid_swapped = 1;
 	temporarily_use_uid(pw);
 
-	ok = process_principals(f, NULL, pw, cert);
+	ok = process_principals(f, "(command)", pw, cert);
 
 	fclose(f);
 	f = NULL;
 
-	if (exited_cleanly(pid, "AuthorizedPrincipalsCommand", command) != 0)
+	if (exited_cleanly(pid, "AuthorizedPrincipalsCommand", command, 0) != 0)
 		goto out;
 
 	/* Read completed successfully */
@@ -761,26 +464,25 @@ match_principals_command(struct passwd *user_pw, const struct sshkey *key)
  * returns 1 if the key is allowed or 0 otherwise.
  */
 static int
-check_authkeys_file(FILE *f, char *file, Key* key, struct passwd *pw)
+check_authkeys_file(FILE *f, char *file, struct sshkey *key, struct passwd *pw)
 {
 	char line[SSH_MAX_PUBKEY_BYTES];
 	int found_key = 0;
 	u_long linenum = 0;
-	Key *found;
-
-	found_key = 0;
+	struct sshkey *found = NULL;
 
-	found = NULL;
 	while (read_keyfile_line(f, file, line, sizeof(line), &linenum) != -1) {
 		char *cp, *key_options = NULL, *fp = NULL;
 		const char *reason = NULL;
 
-		/* Always consume entrire file */
+		/* Always consume entire file */
 		if (found_key)
 			continue;
 		if (found != NULL)
-			key_free(found);
-		found = key_new(key_is_cert(key) ? KEY_UNSPEC : key->type);
+			sshkey_free(found);
+		found = sshkey_new(sshkey_is_cert(key) ? KEY_UNSPEC : key->type);
+		if (found == NULL)
+			goto done;
 		auth_clear_options();
 
 		/* Skip leading whitespace, empty and comment lines. */
@@ -789,7 +491,7 @@ check_authkeys_file(FILE *f, char *file, Key* key, struct passwd *pw)
 		if (!*cp || *cp == '\n' || *cp == '#')
 			continue;
 
-		if (key_read(found, &cp) != 1) {
+		if (sshkey_read(found, &cp) != 0) {
 			/* no key?  check if there are options for this key */
 			int quoted = 0;
 			debug2("user_key_allowed: check options: '%s'", cp);
@@ -803,14 +505,14 @@ check_authkeys_file(FILE *f, char *file, Key* key, struct passwd *pw)
 			/* Skip remaining whitespace. */
 			for (; *cp == ' ' || *cp == '\t'; cp++)
 				;
-			if (key_read(found, &cp) != 1) {
+			if (sshkey_read(found, &cp) != 0) {
 				debug2("user_key_allowed: advance: '%s'", cp);
 				/* still no key?  advance to next line*/
 				continue;
 			}
 		}
-		if (key_is_cert(key)) {
-			if (!key_equal(found, key->cert->signature_key))
+		if (sshkey_is_cert(key)) {
+			if (!sshkey_equal(found, key->cert->signature_key))
 				continue;
 			if (auth_parse_options(pw, key_options, file,
 			    linenum) != 1)
@@ -821,7 +523,7 @@ check_authkeys_file(FILE *f, char *file, Key* key, struct passwd *pw)
 			    options.fingerprint_hash, SSH_FP_DEFAULT)) == NULL)
 				continue;
 			debug("matching CA found: file %s, line %lu, %s %s",
-			    file, linenum, key_type(found), fp);
+			    file, linenum, sshkey_type(found), fp);
 			/*
 			 * If the user has specified a list of principals as
 			 * a key option, then prefer that list to matching
@@ -838,7 +540,7 @@ check_authkeys_file(FILE *f, char *file, Key* key, struct passwd *pw)
 				auth_debug_add("%s", reason);
 				continue;
 			}
-			if (key_cert_check_authority(key, 0, 0,
+			if (sshkey_cert_check_authority(key, 0, 0,
 			    authorized_principals == NULL ? pw->pw_name : NULL,
 			    &reason) != 0)
 				goto fail_reason;
@@ -847,11 +549,11 @@ check_authkeys_file(FILE *f, char *file, Key* key, struct passwd *pw)
 			verbose("Accepted certificate ID \"%s\" (serial %llu) "
 			    "signed by %s CA %s via %s", key->cert->key_id,
 			    (unsigned long long)key->cert->serial,
-			    key_type(found), fp, file);
+			    sshkey_type(found), fp, file);
 			free(fp);
 			found_key = 1;
 			break;
-		} else if (key_equal(found, key)) {
+		} else if (sshkey_equal(found, key)) {
 			if (auth_parse_options(pw, key_options, file,
 			    linenum) != 1)
 				continue;
@@ -861,14 +563,15 @@ check_authkeys_file(FILE *f, char *file, Key* key, struct passwd *pw)
 			    options.fingerprint_hash, SSH_FP_DEFAULT)) == NULL)
 				continue;
 			debug("matching key found: file %s, line %lu %s %s",
-			    file, linenum, key_type(found), fp);
+			    file, linenum, sshkey_type(found), fp);
 			free(fp);
 			found_key = 1;
 			continue;
 		}
 	}
+ done:
 	if (found != NULL)
-		key_free(found);
+		sshkey_free(found);
 	if (!found_key)
 		debug2("key not found");
 	return found_key;
@@ -876,24 +579,24 @@ check_authkeys_file(FILE *f, char *file, Key* key, struct passwd *pw)
 
 /* Authenticate a certificate key against TrustedUserCAKeys */
 static int
-user_cert_trusted_ca(struct passwd *pw, Key *key)
+user_cert_trusted_ca(struct passwd *pw, struct sshkey *key)
 {
 	char *ca_fp, *principals_file = NULL;
 	const char *reason;
-	int ret = 0, found_principal = 0, use_authorized_principals;
+	int r, ret = 0, found_principal = 0, use_authorized_principals;
 
-	if (!key_is_cert(key) || options.trusted_user_ca_keys == NULL)
+	if (!sshkey_is_cert(key) || options.trusted_user_ca_keys == NULL)
 		return 0;
 
 	if ((ca_fp = sshkey_fingerprint(key->cert->signature_key,
 	    options.fingerprint_hash, SSH_FP_DEFAULT)) == NULL)
 		return 0;
 
-	if (sshkey_in_file(key->cert->signature_key,
-	    options.trusted_user_ca_keys, 1, 0) != 0) {
-		debug2("%s: CA %s %s is not listed in %s", __func__,
-		    key_type(key->cert->signature_key), ca_fp,
-		    options.trusted_user_ca_keys);
+	if ((r = sshkey_in_file(key->cert->signature_key,
+	    options.trusted_user_ca_keys, 1, 0)) != 0) {
+		debug2("%s: CA %s %s is not listed in %s: %s", __func__,
+		    sshkey_type(key->cert->signature_key), ca_fp,
+		    options.trusted_user_ca_keys, ssh_err(r));
 		goto out;
 	}
 	/*
@@ -918,7 +621,7 @@ user_cert_trusted_ca(struct passwd *pw, Key *key)
 		auth_debug_add("%s", reason);
 		goto out;
 	}
-	if (key_cert_check_authority(key, 0, 1,
+	if (sshkey_cert_check_authority(key, 0, 1,
 	    use_authorized_principals ? NULL : pw->pw_name, &reason) != 0)
 		goto fail_reason;
 	if (auth_cert_options(key, pw, &reason) != 0)
@@ -927,7 +630,7 @@ user_cert_trusted_ca(struct passwd *pw, Key *key)
 	verbose("Accepted certificate ID \"%s\" (serial %llu) signed by "
 	    "%s CA %s via %s", key->cert->key_id,
 	    (unsigned long long)key->cert->serial,
-	    key_type(key->cert->signature_key), ca_fp,
+	    sshkey_type(key->cert->signature_key), ca_fp,
 	    options.trusted_user_ca_keys);
 	ret = 1;
 
@@ -942,7 +645,7 @@ user_cert_trusted_ca(struct passwd *pw, Key *key)
  * returns 1 if the key is allowed or 0 otherwise.
  */
 static int
-user_key_allowed2(struct passwd *pw, Key *key, char *file)
+user_key_allowed2(struct passwd *pw, struct sshkey *key, char *file)
 {
 	FILE *f;
 	int found_key = 0;
@@ -965,7 +668,7 @@ user_key_allowed2(struct passwd *pw, Key *key, char *file)
  * returns 1 if the key is allowed or 0 otherwise.
  */
 static int
-user_key_command_allowed2(struct passwd *user_pw, Key *key)
+user_key_command_allowed2(struct passwd *user_pw, struct sshkey *key)
 {
 	FILE *f = NULL;
 	int r, ok, found_key = 0;
@@ -1011,7 +714,7 @@ user_key_command_allowed2(struct passwd *user_pw, Key *key)
 	}
 
 	/* Turn the command into an argument vector */
-	if (split_argv(options.authorized_keys_command, &ac, &av) != 0) {
+	if (argv_split(options.authorized_keys_command, &ac, &av) != 0) {
 		error("AuthorizedKeysCommand \"%s\" contains invalid quotes",
 		    command);
 		goto out;
@@ -1035,7 +738,7 @@ user_key_command_allowed2(struct passwd *user_pw, Key *key)
 		av[i] = tmp;
 	}
 	/* Prepare a printable command for logs, etc. */
-	command = assemble_argv(ac, av);
+	command = argv_assemble(ac, av);
 
 	/*
 	 * If AuthorizedKeysCommand was run without arguments
@@ -1052,7 +755,8 @@ user_key_command_allowed2(struct passwd *user_pw, Key *key)
 	}
 
 	if ((pid = subprocess("AuthorizedKeysCommand", pw, command,
-	    ac, av, &f)) == 0)
+	    ac, av, &f,
+	    SSH_SUBPROCESS_STDOUT_CAPTURE|SSH_SUBPROCESS_STDERR_DISCARD)) == 0)
 		goto out;
 
 	uid_swapped = 1;
@@ -1063,7 +767,7 @@ user_key_command_allowed2(struct passwd *user_pw, Key *key)
 	fclose(f);
 	f = NULL;
 
-	if (exited_cleanly(pid, "AuthorizedKeysCommand", command) != 0)
+	if (exited_cleanly(pid, "AuthorizedKeysCommand", command, 0) != 0)
 		goto out;
 
 	/* Read completed successfully */
@@ -1088,14 +792,15 @@ user_key_command_allowed2(struct passwd *user_pw, Key *key)
  * Check whether key authenticates and authorises the user.
  */
 int
-user_key_allowed(struct passwd *pw, Key *key, int auth_attempt)
+user_key_allowed(struct passwd *pw, struct sshkey *key, int auth_attempt)
 {
 	u_int success, i;
 	char *file;
 
 	if (auth_key_is_revoked(key))
 		return 0;
-	if (key_is_cert(key) && auth_key_is_revoked(key->cert->signature_key))
+	if (sshkey_is_cert(key) &&
+	    auth_key_is_revoked(key->cert->signature_key))
 		return 0;
 
 	success = user_cert_trusted_ca(pw, key);
@@ -1120,35 +825,6 @@ user_key_allowed(struct passwd *pw, Key *key, int auth_attempt)
 	return success;
 }
 
-/* Records a public key in the list of previously-successful keys */
-void
-auth2_record_userkey(Authctxt *authctxt, struct sshkey *key)
-{
-	struct sshkey **tmp;
-
-	if (authctxt->nprev_userkeys >= INT_MAX ||
-	    (tmp = reallocarray(authctxt->prev_userkeys,
-	    authctxt->nprev_userkeys + 1, sizeof(*tmp))) == NULL)
-		fatal("%s: reallocarray failed", __func__);
-	authctxt->prev_userkeys = tmp;
-	authctxt->prev_userkeys[authctxt->nprev_userkeys] = key;
-	authctxt->nprev_userkeys++;
-}
-
-/* Checks whether a key has already been used successfully for authentication */
-int
-auth2_userkey_already_used(Authctxt *authctxt, struct sshkey *key)
-{
-	u_int i;
-
-	for (i = 0; i < authctxt->nprev_userkeys; i++) {
-		if (sshkey_equal_public(key, authctxt->prev_userkeys[i])) {
-			return 1;
-		}
-	}
-	return 0;
-}
-
 Authmethod method_pubkey = {
 	"publickey",
 	userauth_pubkey,