1 files changed, 524 insertions, 235 deletions

diff --git a/ssh-keygen.c b/ssh-keygen.c
index 37e516ff2..d90b1dfdd 100644
--- a/ssh-keygen.c
+++ b/ssh-keygen.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: ssh-keygen.c,v 1.185 2010/03/15 19:40:02 stevesk Exp $ */
+/* $OpenBSD: ssh-keygen.c,v 1.197 2010/08/04 06:07:11 djm Exp $ */
 /*
  * Author: Tatu Ylonen <ylo@cs.hut.fi>
  * Copyright (c) 1994 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
@@ -105,6 +105,9 @@ char *identity_comment = NULL;
 /* Path to CA key when certifying keys. */
 char *ca_key_path = NULL;
 
+/* Certificate serial number */
+long long cert_serial = 0;
+
 /* Key type when certifying */
 u_int cert_key_type = SSH2_CERT_TYPE_USER;
 
@@ -118,27 +121,34 @@ char *cert_principals = NULL;
 u_int64_t cert_valid_from = 0;
 u_int64_t cert_valid_to = ~0ULL;
 
-/* Certificate constraints */
-#define CONSTRAINT_X_FWD        (1)
-#define CONSTRAINT_AGENT_FWD    (1<<1)
-#define CONSTRAINT_PORT_FWD     (1<<2)
-#define CONSTRAINT_PTY          (1<<3)
-#define CONSTRAINT_USER_RC      (1<<4)
-#define CONSTRAINT_DEFAULT      (CONSTRAINT_X_FWD|CONSTRAINT_AGENT_FWD| \
-                                CONSTRAINT_PORT_FWD|CONSTRAINT_PTY| \
-                                CONSTRAINT_USER_RC)
-u_int32_t constraint_flags = CONSTRAINT_DEFAULT;
-char *constraint_command = NULL;
-char *constraint_src_addr = NULL;
-
-/* Dump public key file in format used by real and the original SSH 2 */
-int convert_to_ssh2 = 0;
-int convert_from_ssh2 = 0;
+/* Certificate options */
+#define CERTOPT_X_FWD   (1)
+#define CERTOPT_AGENT_FWD       (1<<1)
+#define CERTOPT_PORT_FWD        (1<<2)
+#define CERTOPT_PTY             (1<<3)
+#define CERTOPT_USER_RC (1<<4)
+#define CERTOPT_DEFAULT (CERTOPT_X_FWD|CERTOPT_AGENT_FWD| \
+                         CERTOPT_PORT_FWD|CERTOPT_PTY|CERTOPT_USER_RC)
+u_int32_t certflags_flags = CERTOPT_DEFAULT;
+char *certflags_command = NULL;
+char *certflags_src_addr = NULL;
+
+/* Conversion to/from various formats */
+int convert_to = 0;
+int convert_from = 0;
+enum {
+        FMT_RFC4716,
+        FMT_PKCS8,
+        FMT_PEM
+} convert_format = FMT_RFC4716;
 int print_public = 0;
 int print_generic = 0;
 
 char *key_type_name = NULL;
 
+/* Load key from this PKCS#11 provider */
+char *pkcs11provider = NULL;
+
 /* argv0 */
 extern char *__progname;
 
@@ -161,9 +171,13 @@ ask_filename(struct passwd *pw, const char *prompt)
                 case KEY_RSA1:
                         name = _PATH_SSH_CLIENT_IDENTITY;
                         break;
+                case KEY_DSA_CERT:
+                case KEY_DSA_CERT_V00:
                 case KEY_DSA:
                         name = _PATH_SSH_CLIENT_ID_DSA;
                         break;
+                case KEY_RSA_CERT:
+                case KEY_RSA_CERT_V00:
                 case KEY_RSA:
                         name = _PATH_SSH_CLIENT_ID_RSA;
                         break;
@@ -209,30 +223,12 @@ load_identity(char *filename)
 #define SSH_COM_PRIVATE_KEY_MAGIC       0x3f6ff9eb
 
 static void
-do_convert_to_ssh2(struct passwd *pw)
+do_convert_to_ssh2(struct passwd *pw, Key *k)
 {
-        Key *k;
         u_int len;
         u_char *blob;
         char comment[61];
-        struct stat st;
 
-        if (!have_identity)
-                ask_filename(pw, "Enter file in which the key is");
-        if (stat(identity_file, &st) < 0) {
-                perror(identity_file);
-                exit(1);
-        }
-        if ((k = key_load_public(identity_file, NULL)) == NULL) {
-                if ((k = load_identity(identity_file)) == NULL) {
-                        fprintf(stderr, "load failed\n");
-                        exit(1);
-                }
-        }
-        if (k->type == KEY_RSA1) {
-                fprintf(stderr, "version 1 keys are not supported\n");
-                exit(1);
-        }
         if (key_to_blob(k, &blob, &len) <= 0) {
                 fprintf(stderr, "key_to_blob failed\n");
                 exit(1);
@@ -253,6 +249,81 @@ do_convert_to_ssh2(struct passwd *pw)
 }
 
 static void
+do_convert_to_pkcs8(Key *k)
+{
+        switch (key_type_plain(k->type)) {
+        case KEY_RSA:
+                if (!PEM_write_RSA_PUBKEY(stdout, k->rsa))
+                        fatal("PEM_write_RSA_PUBKEY failed");
+                break;
+        case KEY_DSA:
+                if (!PEM_write_DSA_PUBKEY(stdout, k->dsa))
+                        fatal("PEM_write_DSA_PUBKEY failed");
+                break;
+        default:
+                fatal("%s: unsupported key type %s", __func__, key_type(k));
+        }
+        exit(0);
+}
+
+static void
+do_convert_to_pem(Key *k)
+{
+        switch (key_type_plain(k->type)) {
+        case KEY_RSA:
+                if (!PEM_write_RSAPublicKey(stdout, k->rsa))
+                        fatal("PEM_write_RSAPublicKey failed");
+                break;
+#if notyet /* OpenSSH 0.9.8 lacks this function */
+        case KEY_DSA:
+                if (!PEM_write_DSAPublicKey(stdout, k->dsa))
+                        fatal("PEM_write_DSAPublicKey failed");
+                break;
+#endif
+        default:
+                fatal("%s: unsupported key type %s", __func__, key_type(k));
+        }
+        exit(0);
+}
+
+static void
+do_convert_to(struct passwd *pw)
+{
+        Key *k;
+        struct stat st;
+
+        if (!have_identity)
+                ask_filename(pw, "Enter file in which the key is");
+        if (stat(identity_file, &st) < 0)
+                fatal("%s: %s: %s", __progname, identity_file, strerror(errno));
+        if ((k = key_load_public(identity_file, NULL)) == NULL) {
+                if ((k = load_identity(identity_file)) == NULL) {
+                        fprintf(stderr, "load failed\n");
+                        exit(1);
+                }
+        }
+        if (k->type == KEY_RSA1) {
+                fprintf(stderr, "version 1 keys are not supported\n");
+                exit(1);
+        }
+
+        switch (convert_format) {
+        case FMT_RFC4716:
+                do_convert_to_ssh2(pw, k);
+                break;
+        case FMT_PKCS8:
+                do_convert_to_pkcs8(k);
+                break;
+        case FMT_PEM:
+                do_convert_to_pem(k);
+                break;
+        default:
+                fatal("%s: unknown key format %d", __func__, convert_format);
+        }
+        exit(0);
+}
+
+static void
 buffer_get_bignum_bits(Buffer *b, BIGNUM *value)
 {
         u_int bignum_bits = buffer_get_int(b);
@@ -390,29 +461,18 @@ get_line(FILE *fp, char *line, size_t len)
 }
 
 static void
-do_convert_from_ssh2(struct passwd *pw)
+do_convert_from_ssh2(struct passwd *pw, Key **k, int *private)
 {
-        Key *k;
         int blen;
         u_int len;
         char line[1024];
         u_char blob[8096];
         char encoded[8096];
-        struct stat st;
-        int escaped = 0, private = 0, ok;
+        int escaped = 0;
         FILE *fp;
 
-        if (!have_identity)
-                ask_filename(pw, "Enter file in which the key is");
-        if (stat(identity_file, &st) < 0) {
-                perror(identity_file);
-                exit(1);
-        }
-        fp = fopen(identity_file, "r");
-        if (fp == NULL) {
-                perror(identity_file);
-                exit(1);
-        }
+        if ((fp = fopen(identity_file, "r")) == NULL)
+                fatal("%s: %s: %s", __progname, identity_file, strerror(errno));
         encoded[0] = '\0';
         while ((blen = get_line(fp, line, sizeof(line))) != -1) {
                 if (line[blen - 1] == '\\')
@@ -420,7 +480,7 @@ do_convert_from_ssh2(struct passwd *pw)
                 if (strncmp(line, "----", 4) == 0 ||
                     strstr(line, ": ") != NULL) {
                         if (strstr(line, SSH_COM_PRIVATE_BEGIN) != NULL)
-                                private = 1;
+                                *private = 1;
                         if (strstr(line, " END ") != NULL) {
                                 break;
                         }
@@ -445,26 +505,130 @@ do_convert_from_ssh2(struct passwd *pw)
                 fprintf(stderr, "uudecode failed.\n");
                 exit(1);
         }
-        k = private ?
+        *k = *private ?
             do_convert_private_ssh2_from_blob(blob, blen) :
             key_from_blob(blob, blen);
-        if (k == NULL) {
+        if (*k == NULL) {
                 fprintf(stderr, "decode blob failed.\n");
                 exit(1);
         }
-        ok = private ?
-            (k->type == KEY_DSA ?
-                 PEM_write_DSAPrivateKey(stdout, k->dsa, NULL, NULL, 0, NULL, NULL) :
-                 PEM_write_RSAPrivateKey(stdout, k->rsa, NULL, NULL, 0, NULL, NULL)) :
-            key_write(k, stdout);
+        fclose(fp);
+}
+
+static void
+do_convert_from_pkcs8(Key **k, int *private)
+{
+        EVP_PKEY *pubkey;
+        FILE *fp;
+
+        if ((fp = fopen(identity_file, "r")) == NULL)
+                fatal("%s: %s: %s", __progname, identity_file, strerror(errno));
+        if ((pubkey = PEM_read_PUBKEY(fp, NULL, NULL, NULL)) == NULL) {
+                fatal("%s: %s is not a recognised public key format", __func__,
+                    identity_file);
+        }
+        fclose(fp);
+        switch (EVP_PKEY_type(pubkey->type)) {
+        case EVP_PKEY_RSA:
+                *k = key_new(KEY_UNSPEC);
+                (*k)->type = KEY_RSA;
+                (*k)->rsa = EVP_PKEY_get1_RSA(pubkey);
+                break;
+        case EVP_PKEY_DSA:
+                *k = key_new(KEY_UNSPEC);
+                (*k)->type = KEY_DSA;
+                (*k)->dsa = EVP_PKEY_get1_DSA(pubkey);
+                break;
+        default:
+                fatal("%s: unsupported pubkey type %d", __func__,
+                    EVP_PKEY_type(pubkey->type));
+        }
+        EVP_PKEY_free(pubkey);
+        return;
+}
+
+static void
+do_convert_from_pem(Key **k, int *private)
+{
+        FILE *fp;
+        RSA *rsa;
+#ifdef notyet
+        DSA *dsa;
+#endif
+
+        if ((fp = fopen(identity_file, "r")) == NULL)
+                fatal("%s: %s: %s", __progname, identity_file, strerror(errno));
+        if ((rsa = PEM_read_RSAPublicKey(fp, NULL, NULL, NULL)) != NULL) {
+                *k = key_new(KEY_UNSPEC);
+                (*k)->type = KEY_RSA;
+                (*k)->rsa = rsa;
+                fclose(fp);
+                return;
+        }
+#if notyet /* OpenSSH 0.9.8 lacks this function */
+        rewind(fp);
+        if ((dsa = PEM_read_DSAPublicKey(fp, NULL, NULL, NULL)) != NULL) {
+                *k = key_new(KEY_UNSPEC);
+                (*k)->type = KEY_DSA;
+                (*k)->dsa = dsa;
+                fclose(fp);
+                return;
+        }
+#endif
+        fatal("%s: unrecognised raw private key format", __func__);
+}
+
+static void
+do_convert_from(struct passwd *pw)
+{
+        Key *k = NULL;
+        int private = 0, ok = 0;
+        struct stat st;
+
+        if (!have_identity)
+                ask_filename(pw, "Enter file in which the key is");
+        if (stat(identity_file, &st) < 0)
+                fatal("%s: %s: %s", __progname, identity_file, strerror(errno));
+
+        switch (convert_format) {
+        case FMT_RFC4716:
+                do_convert_from_ssh2(pw, &k, &private);
+                break;
+        case FMT_PKCS8:
+                do_convert_from_pkcs8(&k, &private);
+                break;
+        case FMT_PEM:
+                do_convert_from_pem(&k, &private);
+                break;
+        default:
+                fatal("%s: unknown key format %d", __func__, convert_format);
+        }
+
+        if (!private)
+                ok = key_write(k, stdout);
+                if (ok)
+                        fprintf(stdout, "\n");
+        else {
+                switch (k->type) {
+                case KEY_DSA:
+                        ok = PEM_write_DSAPrivateKey(stdout, k->dsa, NULL,
+                            NULL, 0, NULL, NULL);
+                        break;
+                case KEY_RSA:
+                        ok = PEM_write_RSAPrivateKey(stdout, k->rsa, NULL,
+                            NULL, 0, NULL, NULL);
+                        break;
+                default:
+                        fatal("%s: unsupported key type %s", __func__,
+                            key_type(k));
+                }
+        }
+
         if (!ok) {
                 fprintf(stderr, "key write failed\n");
                 exit(1);
         }
         key_free(k);
-        if (!private)
-                fprintf(stdout, "\n");
-        fclose(fp);
         exit(0);
 }
 
@@ -493,7 +657,7 @@ do_print_public(struct passwd *pw)
 }
 
 static void
-do_download(struct passwd *pw, char *pkcs11provider)
+do_download(struct passwd *pw)
 {
 #ifdef ENABLE_PKCS11
         Key **keys = NULL;
@@ -555,67 +719,68 @@ do_fingerprint(struct passwd *pw)
                 comment = NULL;
         }
 
-        f = fopen(identity_file, "r");
-        if (f != NULL) {
-                while (fgets(line, sizeof(line), f)) {
-                        if ((cp = strchr(line, '\n')) == NULL) {
-                                error("line %d too long: %.40s...",
-                                    num + 1, line);
-                                skip = 1;
-                                continue;
-                        }
-                        num++;
-                        if (skip) {
-                                skip = 0;
-                                continue;
-                        }
-                        *cp = '\0';
+        if ((f = fopen(identity_file, "r")) == NULL)
+                fatal("%s: %s: %s", __progname, identity_file, strerror(errno));
 
-                        /* Skip leading whitespace, empty and comment lines. */
-                        for (cp = line; *cp == ' ' || *cp == '\t'; cp++)
-                                ;
-                        if (!*cp || *cp == '\n' || *cp == '#')
-                                continue;
-                        i = strtol(cp, &ep, 10);
-                        if (i == 0 || ep == NULL || (*ep != ' ' && *ep != '\t')) {
-                                int quoted = 0;
-                                comment = cp;
-                                for (; *cp && (quoted || (*cp != ' ' &&
-                                    *cp != '\t')); cp++) {
-                                        if (*cp == '\\' && cp[1] == '"')
-                                                cp++;   /* Skip both */
-                                        else if (*cp == '"')
-                                                quoted = !quoted;
-                                }
-                                if (!*cp)
-                                        continue;
-                                *cp++ = '\0';
+        while (fgets(line, sizeof(line), f)) {
+                if ((cp = strchr(line, '\n')) == NULL) {
+                        error("line %d too long: %.40s...",
+                            num + 1, line);
+                        skip = 1;
+                        continue;
+                }
+                num++;
+                if (skip) {
+                        skip = 0;
+                        continue;
+                }
+                *cp = '\0';
+
+                /* Skip leading whitespace, empty and comment lines. */
+                for (cp = line; *cp == ' ' || *cp == '\t'; cp++)
+                        ;
+                if (!*cp || *cp == '\n' || *cp == '#')
+                        continue;
+                i = strtol(cp, &ep, 10);
+                if (i == 0 || ep == NULL || (*ep != ' ' && *ep != '\t')) {
+                        int quoted = 0;
+                        comment = cp;
+                        for (; *cp && (quoted || (*cp != ' ' &&
+                            *cp != '\t')); cp++) {
+                                if (*cp == '\\' && cp[1] == '"')
+                                        cp++;   /* Skip both */
+                                else if (*cp == '"')
+                                        quoted = !quoted;
                         }
-                        ep = cp;
-                        public = key_new(KEY_RSA1);
+                        if (!*cp)
+                                continue;
+                        *cp++ = '\0';
+                }
+                ep = cp;
+                public = key_new(KEY_RSA1);
+                if (key_read(public, &cp) != 1) {
+                        cp = ep;
+                        key_free(public);
+                        public = key_new(KEY_UNSPEC);
                         if (key_read(public, &cp) != 1) {
-                                cp = ep;
                                 key_free(public);
-                                public = key_new(KEY_UNSPEC);
-                                if (key_read(public, &cp) != 1) {
-                                        key_free(public);
-                                        continue;
-                                }
+                                continue;
                         }
-                        comment = *cp ? cp : comment;
-                        fp = key_fingerprint(public, fptype, rep);
-                        ra = key_fingerprint(public, SSH_FP_MD5, SSH_FP_RANDOMART);
-                        printf("%u %s %s (%s)\n", key_size(public), fp,
-                            comment ? comment : "no comment", key_type(public));
-                        if (log_level >= SYSLOG_LEVEL_VERBOSE)
-                                printf("%s\n", ra);
-                        xfree(ra);
-                        xfree(fp);
-                        key_free(public);
-                        invalid = 0;
                 }
-                fclose(f);
+                comment = *cp ? cp : comment;
+                fp = key_fingerprint(public, fptype, rep);
+                ra = key_fingerprint(public, SSH_FP_MD5, SSH_FP_RANDOMART);
+                printf("%u %s %s (%s)\n", key_size(public), fp,
+                    comment ? comment : "no comment", key_type(public));
+                if (log_level >= SYSLOG_LEVEL_VERBOSE)
+                        printf("%s\n", ra);
+                xfree(ra);
+                xfree(fp);
+                key_free(public);
+                invalid = 0;
         }
+        fclose(f);
+
         if (invalid) {
                 printf("%s is not a public key file.\n", identity_file);
                 exit(1);
@@ -670,7 +835,7 @@ do_known_hosts(struct passwd *pw, const char *name)
                 have_identity = 1;
         }
         if ((in = fopen(identity_file, "r")) == NULL)
-                fatal("fopen: %s", strerror(errno));
+                fatal("%s: %s: %s", __progname, identity_file, strerror(errno));
 
         /*
          * Find hosts goes to stdout, hash and deletions happen in-place
@@ -1104,7 +1269,7 @@ fmt_validity(u_int64_t valid_from, u_int64_t valid_to)
 }
 
 static void
-add_flag_constraint(Buffer *c, const char *name)
+add_flag_option(Buffer *c, const char *name)
 {
         debug3("%s: %s", __func__, name);
         buffer_put_cstring(c, name);
@@ -1112,7 +1277,7 @@ add_flag_constraint(Buffer *c, const char *name)
 }
 
 static void
-add_string_constraint(Buffer *c, const char *name, const char *value)
+add_string_option(Buffer *c, const char *name, const char *value)
 {
         Buffer b;
 
@@ -1126,25 +1291,62 @@ add_string_constraint(Buffer *c, const char *name, const char *value)
         buffer_free(&b);
 }
 
+#define OPTIONS_CRITICAL        1
+#define OPTIONS_EXTENSIONS      2
 static void
-prepare_constraint_buf(Buffer *c)
+prepare_options_buf(Buffer *c, int which)
 {
-
         buffer_clear(c);
-        if ((constraint_flags & CONSTRAINT_X_FWD) != 0)
-                add_flag_constraint(c, "permit-X11-forwarding");
-        if ((constraint_flags & CONSTRAINT_AGENT_FWD) != 0)
-                add_flag_constraint(c, "permit-agent-forwarding");
-        if ((constraint_flags & CONSTRAINT_PORT_FWD) != 0)
-                add_flag_constraint(c, "permit-port-forwarding");
-        if ((constraint_flags & CONSTRAINT_PTY) != 0)
-                add_flag_constraint(c, "permit-pty");
-        if ((constraint_flags & CONSTRAINT_USER_RC) != 0)
-                add_flag_constraint(c, "permit-user-rc");
-        if (constraint_command != NULL)
-                add_string_constraint(c, "force-command", constraint_command);
-        if (constraint_src_addr != NULL)
-                add_string_constraint(c, "source-address", constraint_src_addr);
+        if ((which & OPTIONS_CRITICAL) != 0 &&
+            certflags_command != NULL)
+                add_string_option(c, "force-command", certflags_command);
+        if ((which & OPTIONS_EXTENSIONS) != 0 &&
+            (certflags_flags & CERTOPT_AGENT_FWD) != 0)
+                add_flag_option(c, "permit-agent-forwarding");
+        if ((which & OPTIONS_EXTENSIONS) != 0 &&
+            (certflags_flags & CERTOPT_PORT_FWD) != 0)
+                add_flag_option(c, "permit-port-forwarding");
+        if ((which & OPTIONS_EXTENSIONS) != 0 &&
+            (certflags_flags & CERTOPT_PTY) != 0)
+                add_flag_option(c, "permit-pty");
+        if ((which & OPTIONS_EXTENSIONS) != 0 &&
+            (certflags_flags & CERTOPT_USER_RC) != 0)
+                add_flag_option(c, "permit-user-rc");
+        if ((which & OPTIONS_EXTENSIONS) != 0 &&
+            (certflags_flags & CERTOPT_X_FWD) != 0)
+                add_flag_option(c, "permit-X11-forwarding");
+        if ((which & OPTIONS_CRITICAL) != 0 &&
+            certflags_src_addr != NULL)
+                add_string_option(c, "source-address", certflags_src_addr);
+}
+
+static Key *
+load_pkcs11_key(char *path)
+{
+#ifdef ENABLE_PKCS11
+        Key **keys = NULL, *public, *private = NULL;
+        int i, nkeys;
+
+        if ((public = key_load_public(path, NULL)) == NULL)
+                fatal("Couldn't load CA public key \"%s\"", path);
+
+        nkeys = pkcs11_add_provider(pkcs11provider, identity_passphrase, &keys);
+        debug3("%s: %d keys", __func__, nkeys);
+        if (nkeys <= 0)
+                fatal("cannot read public key from pkcs11");
+        for (i = 0; i < nkeys; i++) {
+                if (key_equal_public(public, keys[i])) {
+                        private = keys[i];
+                        continue;
+                }
+                key_free(keys[i]);
+        }
+        xfree(keys);
+        key_free(public);
+        return private;
+#else
+        fatal("no pkcs11 support");
+#endif /* ENABLE_PKCS11 */
 }
 
 static void
@@ -1155,9 +1357,33 @@ do_ca_sign(struct passwd *pw, int argc, char **argv)
         Key *ca, *public;
         char *otmp, *tmp, *cp, *out, *comment, **plist = NULL;
         FILE *f;
+        int v00 = 0; /* legacy keys */
+
+        if (key_type_name != NULL) {
+                switch (key_type_from_name(key_type_name)) {
+                case KEY_RSA_CERT_V00:
+                case KEY_DSA_CERT_V00:
+                        v00 = 1;
+                        break;
+                case KEY_UNSPEC:
+                        if (strcasecmp(key_type_name, "v00") == 0) {
+                                v00 = 1;
+                                break;
+                        } else if (strcasecmp(key_type_name, "v01") == 0)
+                                break;
+                        /* FALLTHROUGH */
+                default:
+                        fprintf(stderr, "unknown key type %s\n", key_type_name);
+                        exit(1);
+                }
+        }
 
+        pkcs11_init(1);
         tmp = tilde_expand_filename(ca_key_path, pw->pw_uid);
-        if ((ca = load_identity(tmp)) == NULL)
+        if (pkcs11provider != NULL) {
+                if ((ca = load_pkcs11_key(tmp)) == NULL)
+                        fatal("No PKCS#11 key matching %s found", ca_key_path);
+        } else if ((ca = load_identity(tmp)) == NULL)
                 fatal("Couldn't load CA key \"%s\"", tmp);
         xfree(tmp);
 
@@ -1183,15 +1409,24 @@ do_ca_sign(struct passwd *pw, int argc, char **argv)
                             __func__, tmp, key_type(public));
 
                 /* Prepare certificate to sign */
-                if (key_to_certified(public) != 0)
+                if (key_to_certified(public, v00) != 0)
                         fatal("Could not upgrade key %s to certificate", tmp);
                 public->cert->type = cert_key_type;
+                public->cert->serial = (u_int64_t)cert_serial;
                 public->cert->key_id = xstrdup(cert_key_id);
                 public->cert->nprincipals = n;
                 public->cert->principals = plist;
                 public->cert->valid_after = cert_valid_from;
                 public->cert->valid_before = cert_valid_to;
-                prepare_constraint_buf(&public->cert->constraints);
+                if (v00) {
+                        prepare_options_buf(&public->cert->critical,
+                            OPTIONS_CRITICAL|OPTIONS_EXTENSIONS);
+                } else {
+                        prepare_options_buf(&public->cert->critical,
+                            OPTIONS_CRITICAL);
+                        prepare_options_buf(&public->cert->extensions,
+                            OPTIONS_EXTENSIONS);
+                }
                 public->cert->signature_key = key_from_private(ca);
 
                 if (key_certify(public, ca) != 0)
@@ -1212,17 +1447,19 @@ do_ca_sign(struct passwd *pw, int argc, char **argv)
                 fprintf(f, " %s\n", comment);
                 fclose(f);
 
-                if (!quiet)
-                        logit("Signed %s key %s: id \"%s\"%s%s valid %s",
-                            cert_key_type == SSH2_CERT_TYPE_USER?"user":"host",
-                            out, cert_key_id,
+                if (!quiet) {
+                        logit("Signed %s key %s: id \"%s\" serial %llu%s%s "
+                            "valid %s", key_cert_type(public), 
+                            out, public->cert->key_id, public->cert->serial,
                             cert_principals != NULL ? " for " : "",
                             cert_principals != NULL ? cert_principals : "",
                             fmt_validity(cert_valid_from, cert_valid_to));
+                }
 
                 key_free(public);
                 xfree(out);
         }
+        pkcs11_terminate();
         exit(0);
 }
 
@@ -1321,50 +1558,92 @@ parse_cert_times(char *timespec)
 }
 
 static void
-add_cert_constraint(char *opt)
+add_cert_option(char *opt)
 {
         char *val;
 
         if (strcmp(opt, "clear") == 0)
-                constraint_flags = 0;
+                certflags_flags = 0;
         else if (strcasecmp(opt, "no-x11-forwarding") == 0)
-                constraint_flags &= ~CONSTRAINT_X_FWD;
+                certflags_flags &= ~CERTOPT_X_FWD;
         else if (strcasecmp(opt, "permit-x11-forwarding") == 0)
-                constraint_flags |= CONSTRAINT_X_FWD;
+                certflags_flags |= CERTOPT_X_FWD;
         else if (strcasecmp(opt, "no-agent-forwarding") == 0)
-                constraint_flags &= ~CONSTRAINT_AGENT_FWD;
+                certflags_flags &= ~CERTOPT_AGENT_FWD;
         else if (strcasecmp(opt, "permit-agent-forwarding") == 0)
-                constraint_flags |= CONSTRAINT_AGENT_FWD;
+                certflags_flags |= CERTOPT_AGENT_FWD;
         else if (strcasecmp(opt, "no-port-forwarding") == 0)
-                constraint_flags &= ~CONSTRAINT_PORT_FWD;
+                certflags_flags &= ~CERTOPT_PORT_FWD;
         else if (strcasecmp(opt, "permit-port-forwarding") == 0)
-                constraint_flags |= CONSTRAINT_PORT_FWD;
+                certflags_flags |= CERTOPT_PORT_FWD;
         else if (strcasecmp(opt, "no-pty") == 0)
-                constraint_flags &= ~CONSTRAINT_PTY;
+                certflags_flags &= ~CERTOPT_PTY;
         else if (strcasecmp(opt, "permit-pty") == 0)
-                constraint_flags |= CONSTRAINT_PTY;
+                certflags_flags |= CERTOPT_PTY;
         else if (strcasecmp(opt, "no-user-rc") == 0)
-                constraint_flags &= ~CONSTRAINT_USER_RC;
+                certflags_flags &= ~CERTOPT_USER_RC;
         else if (strcasecmp(opt, "permit-user-rc") == 0)
-                constraint_flags |= CONSTRAINT_USER_RC;
+                certflags_flags |= CERTOPT_USER_RC;
         else if (strncasecmp(opt, "force-command=", 14) == 0) {
                 val = opt + 14;
                 if (*val == '\0')
-                        fatal("Empty force-command constraint");
-                if (constraint_command != NULL)
+                        fatal("Empty force-command option");
+                if (certflags_command != NULL)
                         fatal("force-command already specified");
-                constraint_command = xstrdup(val);
+                certflags_command = xstrdup(val);
         } else if (strncasecmp(opt, "source-address=", 15) == 0) {
                 val = opt + 15;
                 if (*val == '\0')
-                        fatal("Empty source-address constraint");
-                if (constraint_src_addr != NULL)
+                        fatal("Empty source-address option");
+                if (certflags_src_addr != NULL)
                         fatal("source-address already specified");
                 if (addr_match_cidr_list(NULL, val) != 0)
                         fatal("Invalid source-address list");
-                constraint_src_addr = xstrdup(val);
+                certflags_src_addr = xstrdup(val);
         } else
-                fatal("Unsupported certificate constraint \"%s\"", opt);
+                fatal("Unsupported certificate option \"%s\"", opt);
+}
+
+static void
+show_options(const Buffer *optbuf, int v00, int in_critical)
+{
+        u_char *name, *data;
+        u_int dlen;
+        Buffer options, option;
+
+        buffer_init(&options);
+        buffer_append(&options, buffer_ptr(optbuf), buffer_len(optbuf));
+
+        buffer_init(&option);
+        while (buffer_len(&options) != 0) {
+                name = buffer_get_string(&options, NULL);
+                data = buffer_get_string_ptr(&options, &dlen);
+                buffer_append(&option, data, dlen);
+                printf("                %s", name);
+                if ((v00 || !in_critical) && 
+                    (strcmp(name, "permit-X11-forwarding") == 0 ||
+                    strcmp(name, "permit-agent-forwarding") == 0 ||
+                    strcmp(name, "permit-port-forwarding") == 0 ||
+                    strcmp(name, "permit-pty") == 0 ||
+                    strcmp(name, "permit-user-rc") == 0))
+                        printf("\n");
+                else if ((v00 || in_critical) &&
+                    (strcmp(name, "force-command") == 0 ||
+                    strcmp(name, "source-address") == 0)) {
+                        data = buffer_get_string(&option, NULL);
+                        printf(" %s\n", data);
+                        xfree(data);
+                } else {
+                        printf(" UNKNOWN OPTION (len %u)\n",
+                            buffer_len(&option));
+                        buffer_clear(&option);
+                }
+                xfree(name);
+                if (buffer_len(&option) != 0)
+                        fatal("Option corrupt: extra data at end");
+        }
+        buffer_free(&option);
+        buffer_free(&options);
 }
 
 static void
@@ -1373,31 +1652,31 @@ do_show_cert(struct passwd *pw)
         Key *key;
         struct stat st;
         char *key_fp, *ca_fp;
-        Buffer constraints, constraint;
-        u_char *name, *data;
-        u_int i, dlen;
+        u_int i, v00;
 
         if (!have_identity)
                 ask_filename(pw, "Enter file in which the key is");
-        if (stat(identity_file, &st) < 0) {
-                perror(identity_file);
-                exit(1);
-        }
+        if (stat(identity_file, &st) < 0)
+                fatal("%s: %s: %s", __progname, identity_file, strerror(errno));
         if ((key = key_load_public(identity_file, NULL)) == NULL)
                 fatal("%s is not a public key", identity_file);
         if (!key_is_cert(key))
                 fatal("%s is not a certificate", identity_file);
-        
+        v00 = key->type == KEY_RSA_CERT_V00 || key->type == KEY_DSA_CERT_V00;
+
         key_fp = key_fingerprint(key, SSH_FP_MD5, SSH_FP_HEX);
         ca_fp = key_fingerprint(key->cert->signature_key,
             SSH_FP_MD5, SSH_FP_HEX);
 
         printf("%s:\n", identity_file);
-        printf("        %s %s certificate %s\n", key_type(key),
-            key_cert_type(key), key_fp);
-        printf("        Signed by %s CA %s\n",
+        printf("        Type: %s %s certificate\n", key_ssh_name(key),
+            key_cert_type(key));
+        printf("        Public key: %s %s\n", key_type(key), key_fp);
+        printf("        Signing CA: %s %s\n",
             key_type(key->cert->signature_key), ca_fp);
-        printf("        Key ID \"%s\"\n", key->cert->key_id);
+        printf("        Key ID: \"%s\"\n", key->cert->key_id);
+        if (!v00)
+                printf("        Serial: %llu\n", key->cert->serial);
         printf("        Valid: %s\n",
             fmt_validity(key->cert->valid_after, key->cert->valid_before));
         printf("        Principals: ");
@@ -1409,45 +1688,22 @@ do_show_cert(struct passwd *pw)
                             key->cert->principals[i]);
                 printf("\n");
         }
-        printf("        Constraints: ");
-        if (buffer_len(&key->cert->constraints) == 0)
+        printf("        Critical Options: ");
+        if (buffer_len(&key->cert->critical) == 0)
                 printf("(none)\n");
         else {
                 printf("\n");
-                buffer_init(&constraints);
-                buffer_append(&constraints,
-                    buffer_ptr(&key->cert->constraints),
-                    buffer_len(&key->cert->constraints));
-                buffer_init(&constraint);
-                while (buffer_len(&constraints) != 0) {
-                        name = buffer_get_string(&constraints, NULL);
-                        data = buffer_get_string_ptr(&constraints, &dlen);
-                        buffer_append(&constraint, data, dlen);
-                        printf("                %s", name);
-                        if (strcmp(name, "permit-X11-forwarding") == 0 ||
-                            strcmp(name, "permit-agent-forwarding") == 0 ||
-                            strcmp(name, "permit-port-forwarding") == 0 ||
-                            strcmp(name, "permit-pty") == 0 ||
-                            strcmp(name, "permit-user-rc") == 0)
-                                printf("\n");
-                        else if (strcmp(name, "force-command") == 0 ||
-                            strcmp(name, "source-address") == 0) {
-                                data = buffer_get_string(&constraint, NULL);
-                                printf(" %s\n", data);
-                                xfree(data);
-                        } else {
-                                printf(" UNKNOWN CONSTRAINT (len %u)\n",
-                                    buffer_len(&constraint));
-                                buffer_clear(&constraint);
-                        }
-                        xfree(name);
-                        if (buffer_len(&constraint) != 0)
-                                fatal("Constraint corrupt: extra data at end");
+                show_options(&key->cert->critical, v00, 1);
+        }
+        if (!v00) {
+                printf("        Extensions: ");
+                if (buffer_len(&key->cert->extensions) == 0)
+                        printf("(none)\n");
+                else {
+                        printf("\n");
+                        show_options(&key->cert->extensions, v00, 0);
                 }
-                buffer_free(&constraint);
-                buffer_free(&constraints);
         }
-
         exit(0);
 }
 
@@ -1464,7 +1720,7 @@ usage(void)
 #ifdef ENABLE_PKCS11
         fprintf(stderr, "  -D pkcs11   Download public key from pkcs11 token.\n");
 #endif
-        fprintf(stderr, "  -e          Convert OpenSSH to RFC 4716 key file.\n");
+        fprintf(stderr, "  -e          Export OpenSSH to foreign format key file.\n");
         fprintf(stderr, "  -F hostname Find hostname in known hosts file.\n");
         fprintf(stderr, "  -f filename Filename of the key file.\n");
         fprintf(stderr, "  -G file     Generate candidates for DH-GEX moduli.\n");
@@ -1472,26 +1728,28 @@ usage(void)
         fprintf(stderr, "  -H          Hash names in known_hosts file.\n");
         fprintf(stderr, "  -h          Generate host certificate instead of a user certificate.\n");
         fprintf(stderr, "  -I key_id   Key identifier to include in certificate.\n");
-        fprintf(stderr, "  -i          Convert RFC 4716 to OpenSSH key file.\n");
+        fprintf(stderr, "  -i          Import foreign format to OpenSSH key file.\n");
         fprintf(stderr, "  -L          Print the contents of a certificate.\n");
         fprintf(stderr, "  -l          Show fingerprint of key file.\n");
         fprintf(stderr, "  -M memory   Amount of memory (MB) to use for generating DH-GEX moduli.\n");
-        fprintf(stderr, "  -n name,... User/host principal names to include in certificate\n");
+        fprintf(stderr, "  -m key_fmt  Conversion format for -e/-i (PEM|PKCS8|RFC4716).\n");
         fprintf(stderr, "  -N phrase   Provide new passphrase.\n");
-        fprintf(stderr, "  -O cnstr    Specify a certificate constraint.\n");
+        fprintf(stderr, "  -n name,... User/host principal names to include in certificate\n");
+        fprintf(stderr, "  -O option   Specify a certificate option.\n");
         fprintf(stderr, "  -P phrase   Provide old passphrase.\n");
         fprintf(stderr, "  -p          Change passphrase of private key file.\n");
         fprintf(stderr, "  -q          Quiet.\n");
         fprintf(stderr, "  -R hostname Remove host from known_hosts file.\n");
         fprintf(stderr, "  -r hostname Print DNS resource record.\n");
-        fprintf(stderr, "  -s ca_key   Certify keys with CA key.\n");
         fprintf(stderr, "  -S start    Start point (hex) for generating DH-GEX moduli.\n");
+        fprintf(stderr, "  -s ca_key   Certify keys with CA key.\n");
         fprintf(stderr, "  -T file     Screen candidates for DH-GEX moduli.\n");
         fprintf(stderr, "  -t type     Specify type of key to create.\n");
         fprintf(stderr, "  -V from:to  Specify certificate validity interval.\n");
         fprintf(stderr, "  -v          Verbose.\n");
         fprintf(stderr, "  -W gen      Generator to use for generating DH-GEX moduli.\n");
         fprintf(stderr, "  -y          Read private key file and print public key.\n");
+        fprintf(stderr, "  -z serial   Specify a serial number.\n");
 
         exit(1);
 }
@@ -1503,12 +1761,12 @@ int
 main(int argc, char **argv)
 {
         char dotsshdir[MAXPATHLEN], comment[1024], *passphrase1, *passphrase2;
-        char out_file[MAXPATHLEN], *pkcs11provider = NULL;
-        char *rr_hostname = NULL;
+        char out_file[MAXPATHLEN], *rr_hostname = NULL;
         Key *private, *public;
         struct passwd *pw;
         struct stat st;
         int opt, type, fd;
+        u_int maxbits;
         u_int32_t memory = 0, generator_wanted = 0, trials = 100;
         int do_gen_candidates = 0, do_screen_candidates = 0;
         BIGNUM *start = NULL;
@@ -1540,8 +1798,8 @@ main(int argc, char **argv)
                 exit(1);
         }
 
-        while ((opt = getopt(argc, argv, "degiqpclBHLhvxXyF:b:f:t:D:I:P:N:n:"
-            "O:C:r:g:R:T:G:M:S:s:a:V:W:")) != -1) {
+        while ((opt = getopt(argc, argv, "degiqpclBHLhvxXyF:b:f:t:D:I:P:m:N:n:"
+            "O:C:r:g:R:T:G:M:S:s:a:V:W:z:")) != -1) {
                 switch (opt) {
                 case 'b':
                         bits = (u_int32_t)strtonum(optarg, 768, 32768, &errstr);
@@ -1572,6 +1830,21 @@ main(int argc, char **argv)
                 case 'B':
                         print_bubblebabble = 1;
                         break;
+                case 'm':
+                        if (strcasecmp(optarg, "RFC4716") == 0 ||
+                            strcasecmp(optarg, "ssh2") == 0) {
+                                convert_format = FMT_RFC4716;
+                                break;
+                        }
+                        if (strcasecmp(optarg, "PKCS8") == 0) {
+                                convert_format = FMT_PKCS8;
+                                break;
+                        }
+                        if (strcasecmp(optarg, "PEM") == 0) {
+                                convert_format = FMT_PEM;
+                                break;
+                        }
+                        fatal("Unsupported conversion format \"%s\"", optarg);
                 case 'n':
                         cert_principals = optarg;
                         break;
@@ -1597,7 +1870,7 @@ main(int argc, char **argv)
                         identity_new_passphrase = optarg;
                         break;
                 case 'O':
-                        add_cert_constraint(optarg);
+                        add_cert_option(optarg);
                         break;
                 case 'C':
                         identity_comment = optarg;
@@ -1608,16 +1881,16 @@ main(int argc, char **argv)
                 case 'e':
                 case 'x':
                         /* export key */
-                        convert_to_ssh2 = 1;
+                        convert_to = 1;
                         break;
                 case 'h':
                         cert_key_type = SSH2_CERT_TYPE_HOST;
-                        constraint_flags = 0;
+                        certflags_flags = 0;
                         break;
                 case 'i':
                 case 'X':
                         /* import key */
-                        convert_from_ssh2 = 1;
+                        convert_from = 1;
                         break;
                 case 'y':
                         print_public = 1;
@@ -1661,9 +1934,8 @@ main(int argc, char **argv)
                         break;
                 case 'M':
                         memory = (u_int32_t)strtonum(optarg, 1, UINT_MAX, &errstr);
-                        if (errstr) {
+                        if (errstr)
                                 fatal("Memory limit is %s: %s", errstr, optarg);
-                        }
                         break;
                 case 'G':
                         do_gen_candidates = 1;
@@ -1685,6 +1957,11 @@ main(int argc, char **argv)
                 case 'V':
                         parse_cert_times(optarg);
                         break;
+                case 'z':
+                        cert_serial = strtonum(optarg, 0, LLONG_MAX, &errstr);
+                        if (errstr)
+                                fatal("Invalid serial number: %s", errstr);
+                        break;
                 case '?':
                 default:
                         usage();
@@ -1729,10 +2006,10 @@ main(int argc, char **argv)
                 do_change_passphrase(pw);
         if (change_comment)
                 do_change_comment(pw);
-        if (convert_to_ssh2)
-                do_convert_to_ssh2(pw);
-        if (convert_from_ssh2)
-                do_convert_from_ssh2(pw);
+        if (convert_to)
+                do_convert_to(pw);
+        if (convert_from)
+                do_convert_from(pw);
         if (print_public)
                 do_print_public(pw);
         if (rr_hostname != NULL) {
@@ -1759,7 +2036,7 @@ main(int argc, char **argv)
                 }
         }
         if (pkcs11provider != NULL)
-                do_download(pw, pkcs11provider);
+                do_download(pw);
 
         if (do_gen_candidates) {
                 FILE *out = fopen(out_file, "w");
@@ -1811,6 +2088,12 @@ main(int argc, char **argv)
         }
         if (bits == 0)
                 bits = (type == KEY_DSA) ? DEFAULT_BITS_DSA : DEFAULT_BITS;
+        maxbits = (type == KEY_DSA) ?
+            OPENSSL_DSA_MAX_MODULUS_BITS : OPENSSL_RSA_MAX_MODULUS_BITS;
+        if (bits > maxbits) {
+                fprintf(stderr, "key bits exceeds maximum %d\n", maxbits);
+                exit(1);
+        }
         if (type == KEY_DSA && bits != 1024)
                 fatal("DSA keys must be 1024 bits");
         if (!quiet)
@@ -1826,13 +2109,19 @@ main(int argc, char **argv)
                 ask_filename(pw, "Enter file in which to save the key");
 
         /* Create ~/.ssh directory if it doesn't already exist. */
-        snprintf(dotsshdir, sizeof dotsshdir, "%s/%s", pw->pw_dir, _PATH_SSH_USER_DIR);
-        if (strstr(identity_file, dotsshdir) != NULL &&
-            stat(dotsshdir, &st) < 0) {
-                if (mkdir(dotsshdir, 0700) < 0)
-                        error("Could not create directory '%s'.", dotsshdir);
-                else if (!quiet)
-                        printf("Created directory '%s'.\n", dotsshdir);
+        snprintf(dotsshdir, sizeof dotsshdir, "%s/%s",
+            pw->pw_dir, _PATH_SSH_USER_DIR);
+        if (strstr(identity_file, dotsshdir) != NULL) {
+                if (stat(dotsshdir, &st) < 0) {
+                        if (errno != ENOENT) {
+                                error("Could not stat %s: %s", dotsshdir,
+                                    strerror(errno));
+                        } else if (mkdir(dotsshdir, 0700) < 0) {
+                                error("Could not create directory '%s': %s",
+                                    dotsshdir, strerror(errno));
+                        } else if (!quiet)
+                                printf("Created directory '%s'.\n", dotsshdir);
+                }
         }
         /* If the file already exists, ask the user to confirm. */
         if (stat(identity_file, &st) >= 0) {