1 files changed, 203 insertions, 89 deletions

diff --git a/ssh-keygen.c b/ssh-keygen.c
index f17af036b..835f7d016 100644
--- a/ssh-keygen.c
+++ b/ssh-keygen.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: ssh-keygen.c,v 1.299 2017/03/10 04:26:06 djm Exp $ */
+/* $OpenBSD: ssh-keygen.c,v 1.307 2017/07/07 03:53:12 djm Exp $ */
 /*
  * Author: Tatu Ylonen <ylo@cs.hut.fi>
  * Copyright (c) 1994 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
@@ -41,7 +41,6 @@
 
 #include "xmalloc.h"
 #include "sshkey.h"
-#include "rsa.h"
 #include "authfile.h"
 #include "uuencode.h"
 #include "sshbuf.h"
@@ -59,6 +58,7 @@
 #include "krl.h"
 #include "digest.h"
 #include "utf8.h"
+#include "authfd.h"
 
 #ifdef WITH_OPENSSL
 # define DEFAULT_KEY_TYPE_NAME "rsa"
@@ -121,6 +121,9 @@ char *identity_comment = NULL;
 /* Path to CA key when certifying keys. */
 char *ca_key_path = NULL;
 
+/* Prefer to use agent keys for CA signing */
+int prefer_agent = 0;
+
 /* Certificate serial number */
 unsigned long long cert_serial = 0;
 
@@ -149,6 +152,15 @@ u_int32_t certflags_flags = CERTOPT_DEFAULT;
 char *certflags_command = NULL;
 char *certflags_src_addr = NULL;
 
+/* Arbitrary extensions specified by user */
+struct cert_userext {
+        char *key;
+        char *val;
+        int crit;
+};
+struct cert_userext *cert_userext;
+size_t ncert_userext;
+
 /* Conversion to/from various formats */
 int convert_to = 0;
 int convert_from = 0;
@@ -217,13 +229,21 @@ type_bits_valid(int type, const char *name, u_int32_t *bitsp)
             OPENSSL_DSA_MAX_MODULUS_BITS : OPENSSL_RSA_MAX_MODULUS_BITS;
         if (*bitsp > maxbits)
                 fatal("key bits exceeds maximum %d", maxbits);
-        if (type == KEY_DSA && *bitsp != 1024)
-                fatal("DSA keys must be 1024 bits");
-        else if (type != KEY_ECDSA && type != KEY_ED25519 && *bitsp < 1024)
-                fatal("Key must at least be 1024 bits");
-        else if (type == KEY_ECDSA && sshkey_ecdsa_bits_to_nid(*bitsp) == -1)
-                fatal("Invalid ECDSA key length - valid lengths are "
-                    "256, 384 or 521 bits");
+        switch (type) {
+        case KEY_DSA:
+                if (*bitsp != 1024)
+                        fatal("Invalid DSA key length: must be 1024 bits");
+                break;
+        case KEY_RSA:
+                if (*bitsp < SSH_RSA_MINIMUM_MODULUS_SIZE)
+                        fatal("Invalid RSA key length: minimum is %d bits",
+                            SSH_RSA_MINIMUM_MODULUS_SIZE);
+                break;
+        case KEY_ECDSA:
+                if (sshkey_ecdsa_bits_to_nid(*bitsp) == -1)
+                        fatal("Invalid ECDSA key length: valid lengths are "
+                            "256, 384 or 521 bits");
+        }
 #endif
 }
 
@@ -237,9 +257,6 @@ ask_filename(struct passwd *pw, const char *prompt)
                 name = _PATH_SSH_CLIENT_ID_RSA;
         else {
                 switch (sshkey_type_from_name(key_type_name)) {
-                case KEY_RSA1:
-                        name = _PATH_SSH_CLIENT_IDENTITY;
-                        break;
                 case KEY_DSA_CERT:
                 case KEY_DSA:
                         name = _PATH_SSH_CLIENT_ID_DSA;
@@ -311,8 +328,6 @@ do_convert_to_ssh2(struct passwd *pw, struct sshkey *k)
         char comment[61];
         int r;
 
-        if (k->type == KEY_RSA1)
-                fatal("version 1 keys are not supported");
         if ((r = sshkey_to_blob(k, &blob, &len)) != 0)
                 fatal("key_to_blob failed: %s", ssh_err(r));
         /* Comment + surrounds must fit into 72 chars (RFC 4716 sec 3.3) */
@@ -334,7 +349,6 @@ static void
 do_convert_to_pkcs8(struct sshkey *k)
 {
         switch (sshkey_type_plain(k->type)) {
-        case KEY_RSA1:
         case KEY_RSA:
                 if (!PEM_write_RSA_PUBKEY(stdout, k->rsa))
                         fatal("PEM_write_RSA_PUBKEY failed");
@@ -359,7 +373,6 @@ static void
 do_convert_to_pem(struct sshkey *k)
 {
         switch (sshkey_type_plain(k->type)) {
-        case KEY_RSA1:
         case KEY_RSA:
                 if (!PEM_write_RSAPublicKey(stdout, k->rsa))
                         fatal("PEM_write_RSAPublicKey failed");
@@ -478,7 +491,7 @@ do_convert_private_ssh2_from_blob(u_char *blob, u_int blen)
                 return NULL;
         }
         if ((key = sshkey_new_private(ktype)) == NULL)
-                fatal("key_new_private failed");
+                fatal("sshkey_new_private failed");
         free(type);
 
         switch (key->type) {
@@ -514,7 +527,7 @@ do_convert_private_ssh2_from_blob(u_char *blob, u_int blen)
                 buffer_get_bignum_bits(b, key->rsa->iqmp);
                 buffer_get_bignum_bits(b, key->rsa->q);
                 buffer_get_bignum_bits(b, key->rsa->p);
-                if ((r = rsa_generate_additional_parameters(key->rsa)) != 0)
+                if ((r = ssh_rsa_generate_additional_parameters(key)) != 0)
                         fatal("generate RSA parameters failed: %s", ssh_err(r));
                 break;
         }
@@ -760,7 +773,7 @@ do_print_public(struct passwd *pw)
                 fatal("%s: %s", identity_file, strerror(errno));
         prv = load_identity(identity_file);
         if ((r = sshkey_write(prv, stdout)) != 0)
-                error("key_write failed: %s", ssh_err(r));
+                error("sshkey_write failed: %s", ssh_err(r));
         sshkey_free(prv);
         fprintf(stdout, "\n");
         exit(0);
@@ -816,13 +829,6 @@ try_read_key(char **cpp)
         struct sshkey *ret;
         int r;
 
-        if ((ret = sshkey_new(KEY_RSA1)) == NULL)
-                fatal("sshkey_new failed");
-        /* Try RSA1 */
-        if ((r = sshkey_read(ret, cpp)) == 0)
-                return ret;
-        /* Try modern */
-        sshkey_free(ret);
         if ((ret = sshkey_new(KEY_UNSPEC)) == NULL)
                 fatal("sshkey_new failed");
         if ((r = sshkey_read(ret, cpp)) == 0)
@@ -978,9 +984,6 @@ do_gen_all_hostkeys(struct passwd *pw)
                 char *path;
         } key_types[] = {
 #ifdef WITH_OPENSSL
-#ifdef WITH_SSH1
-                { "rsa1", "RSA1", _PATH_HOST_KEY_FILE },
-#endif /* WITH_SSH1 */
                 { "rsa", "RSA" ,_PATH_HOST_RSA_KEY_FILE },
                 { "dsa", "DSA", _PATH_HOST_DSA_KEY_FILE },
 #ifdef OPENSSL_HAS_ECC
@@ -994,20 +997,38 @@ do_gen_all_hostkeys(struct passwd *pw)
         int first = 0;
         struct stat st;
         struct sshkey *private, *public;
-        char comment[1024];
+        char comment[1024], *prv_tmp, *pub_tmp, *prv_file, *pub_file;
         int i, type, fd, r;
         FILE *f;
 
         for (i = 0; key_types[i].key_type; i++) {
-                if (stat(key_types[i].path, &st) == 0)
-                        continue;
-                if (errno != ENOENT) {
+                public = private = NULL;
+                prv_tmp = pub_tmp = prv_file = pub_file = NULL;
+
+                xasprintf(&prv_file, "%s%s",
+                    identity_file, key_types[i].path);
+
+                /* Check whether private key exists and is not zero-length */
+                if (stat(prv_file, &st) == 0) {
+                        if (st.st_size != 0)
+                                goto next;
+                } else if (errno != ENOENT) {
                         error("Could not stat %s: %s", key_types[i].path,
                             strerror(errno));
-                        first = 0;
-                        continue;
+                        goto failnext;
                 }
 
+                /*
+                 * Private key doesn't exist or is invalid; proceed with
+                 * key generation.
+                 */
+                xasprintf(&prv_tmp, "%s%s.XXXXXXXXXX",
+                    identity_file, key_types[i].path);
+                xasprintf(&pub_tmp, "%s%s.pub.XXXXXXXXXX",
+                    identity_file, key_types[i].path);
+                xasprintf(&pub_file, "%s%s.pub",
+                    identity_file, key_types[i].path);
+
                 if (first == 0) {
                         first = 1;
                         printf("%s: generating new host keys: ", __progname);
@@ -1015,56 +1036,76 @@ do_gen_all_hostkeys(struct passwd *pw)
                 printf("%s ", key_types[i].key_type_display);
                 fflush(stdout);
                 type = sshkey_type_from_name(key_types[i].key_type);
-                strlcpy(identity_file, key_types[i].path, sizeof(identity_file));
+                if ((fd = mkstemp(prv_tmp)) == -1) {
+                        error("Could not save your public key in %s: %s",
+                            prv_tmp, strerror(errno));
+                        goto failnext;
+                }
+                close(fd); /* just using mkstemp() to generate/reserve a name */
                 bits = 0;
                 type_bits_valid(type, NULL, &bits);
                 if ((r = sshkey_generate(type, bits, &private)) != 0) {
-                        error("key_generate failed: %s", ssh_err(r));
-                        first = 0;
-                        continue;
+                        error("sshkey_generate failed: %s", ssh_err(r));
+                        goto failnext;
                 }
                 if ((r = sshkey_from_private(private, &public)) != 0)
                         fatal("sshkey_from_private failed: %s", ssh_err(r));
                 snprintf(comment, sizeof comment, "%s@%s", pw->pw_name,
                     hostname);
-                if ((r = sshkey_save_private(private, identity_file, "",
+                if ((r = sshkey_save_private(private, prv_tmp, "",
                     comment, use_new_format, new_format_cipher, rounds)) != 0) {
                         error("Saving key \"%s\" failed: %s",
-                            identity_file, ssh_err(r));
-                        sshkey_free(private);
-                        sshkey_free(public);
-                        first = 0;
-                        continue;
+                            prv_tmp, ssh_err(r));
+                        goto failnext;
                 }
-                sshkey_free(private);
-                strlcat(identity_file, ".pub", sizeof(identity_file));
-                fd = open(identity_file, O_WRONLY | O_CREAT | O_TRUNC, 0644);
-                if (fd == -1) {
-                        error("Could not save your public key in %s",
-                            identity_file);
-                        sshkey_free(public);
-                        first = 0;
-                        continue;
+                if ((fd = mkstemp(pub_tmp)) == -1) {
+                        error("Could not save your public key in %s: %s",
+                            pub_tmp, strerror(errno));
+                        goto failnext;
                 }
+                (void)fchmod(fd, 0644);
                 f = fdopen(fd, "w");
                 if (f == NULL) {
-                        error("fdopen %s failed", identity_file);
+                        error("fdopen %s failed: %s", pub_tmp, strerror(errno));
                         close(fd);
-                        sshkey_free(public);
-                        first = 0;
-                        continue;
+                        goto failnext;
                 }
                 if ((r = sshkey_write(public, f)) != 0) {
                         error("write key failed: %s", ssh_err(r));
                         fclose(f);
-                        sshkey_free(public);
-                        first = 0;
-                        continue;
+                        goto failnext;
                 }
                 fprintf(f, " %s\n", comment);
-                fclose(f);
-                sshkey_free(public);
+                if (ferror(f) != 0) {
+                        error("write key failed: %s", strerror(errno));
+                        fclose(f);
+                        goto failnext;
+                }
+                if (fclose(f) != 0) {
+                        error("key close failed: %s", strerror(errno));
+                        goto failnext;
+                }
 
+                /* Rename temporary files to their permanent locations. */
+                if (rename(pub_tmp, pub_file) != 0) {
+                        error("Unable to move %s into position: %s",
+                            pub_file, strerror(errno));
+                        goto failnext;
+                }
+                if (rename(prv_tmp, prv_file) != 0) {
+                        error("Unable to move %s into position: %s",
+                            key_types[i].path, strerror(errno));
+ failnext:
+                        first = 0;
+                        goto next;
+                }
+ next:
+                sshkey_free(private);
+                sshkey_free(public);
+                free(prv_tmp);
+                free(pub_tmp);
+                free(prv_file);
+                free(pub_file);
         }
         if (first != 0)
                 printf("\n");
@@ -1436,9 +1477,8 @@ do_change_comment(struct passwd *pw)
                 }
         }
 
-        if (private->type != KEY_RSA1 && private->type != KEY_ED25519 &&
-            !use_new_format) {
-                error("Comments are only supported for RSA1 or keys stored in "
+        if (private->type != KEY_ED25519 && !use_new_format) {
+                error("Comments are only supported for keys stored in "
                     "the new format (-o).");
                 explicit_bzero(passphrase, strlen(passphrase));
                 sshkey_free(private);
@@ -1476,7 +1516,7 @@ do_change_comment(struct passwd *pw)
         explicit_bzero(passphrase, strlen(passphrase));
         free(passphrase);
         if ((r = sshkey_from_private(private, &public)) != 0)
-                fatal("key_from_private failed: %s", ssh_err(r));
+                fatal("sshkey_from_private failed: %s", ssh_err(r));
         sshkey_free(private);
 
         strlcat(identity_file, ".pub", sizeof(identity_file));
@@ -1531,6 +1571,8 @@ add_string_option(struct sshbuf *c, const char *name, const char *value)
 static void
 prepare_options_buf(struct sshbuf *c, int which)
 {
+        size_t i;
+
         sshbuf_reset(c);
         if ((which & OPTIONS_CRITICAL) != 0 &&
             certflags_command != NULL)
@@ -1553,6 +1595,17 @@ prepare_options_buf(struct sshbuf *c, int which)
         if ((which & OPTIONS_CRITICAL) != 0 &&
             certflags_src_addr != NULL)
                 add_string_option(c, "source-address", certflags_src_addr);
+        for (i = 0; i < ncert_userext; i++) {
+                if ((cert_userext[i].crit && (which & OPTIONS_EXTENSIONS)) ||
+                    (!cert_userext[i].crit && (which & OPTIONS_CRITICAL)))
+                        continue;
+                if (cert_userext[i].val == NULL)
+                        add_flag_option(c, cert_userext[i].key);
+                else {
+                        add_string_option(c, cert_userext[i].key,
+                            cert_userext[i].val);
+                }
+        }
 }
 
 static struct sshkey *
@@ -1585,24 +1638,66 @@ load_pkcs11_key(char *path)
 #endif /* ENABLE_PKCS11 */
 }
 
+/* Signer for sshkey_certify_custom that uses the agent */
+static int
+agent_signer(const struct sshkey *key, u_char **sigp, size_t *lenp,
+    const u_char *data, size_t datalen,
+    const char *alg, u_int compat, void *ctx)
+{
+        int *agent_fdp = (int *)ctx;
+
+        return ssh_agent_sign(*agent_fdp, key, sigp, lenp,
+            data, datalen, alg, compat);
+}
+
 static void
 do_ca_sign(struct passwd *pw, int argc, char **argv)
 {
-        int r, i, fd;
+        int r, i, fd, found, agent_fd = -1;
         u_int n;
         struct sshkey *ca, *public;
         char valid[64], *otmp, *tmp, *cp, *out, *comment, **plist = NULL;
         FILE *f;
+        struct ssh_identitylist *agent_ids;
+        size_t j;
 
 #ifdef ENABLE_PKCS11
         pkcs11_init(1);
 #endif
         tmp = tilde_expand_filename(ca_key_path, pw->pw_uid);
         if (pkcs11provider != NULL) {
+                /* If a PKCS#11 token was specified then try to use it */
                 if ((ca = load_pkcs11_key(tmp)) == NULL)
                         fatal("No PKCS#11 key matching %s found", ca_key_path);
-        } else
+        } else if (prefer_agent) {
+                /*
+                 * Agent signature requested. Try to use agent after making
+                 * sure the public key specified is actually present in the
+                 * agent.
+                 */
+                if ((r = sshkey_load_public(tmp, &ca, NULL)) != 0)
+                        fatal("Cannot load CA public key %s: %s",
+                            tmp, ssh_err(r));
+                if ((r = ssh_get_authentication_socket(&agent_fd)) != 0)
+                        fatal("Cannot use public key for CA signature: %s",
+                            ssh_err(r));
+                if ((r = ssh_fetch_identitylist(agent_fd, &agent_ids)) != 0)
+                        fatal("Retrieve agent key list: %s", ssh_err(r));
+                found = 0;
+                for (j = 0; j < agent_ids->nkeys; j++) {
+                        if (sshkey_equal(ca, agent_ids->keys[j])) {
+                                found = 1;
+                                break;
+                        }
+                }
+                if (!found)
+                        fatal("CA key %s not found in agent", tmp);
+                ssh_free_identitylist(agent_ids);
+                ca->flags |= SSHKEY_FLAG_EXT;
+        } else {
+                /* CA key is assumed to be a private key on the filesystem */
                 ca = load_identity(tmp);
+        }
         free(tmp);
 
         if (key_type_name != NULL &&
@@ -1650,10 +1745,18 @@ do_ca_sign(struct passwd *pw, int argc, char **argv)
                     OPTIONS_EXTENSIONS);
                 if ((r = sshkey_from_private(ca,
                     &public->cert->signature_key)) != 0)
-                        fatal("key_from_private (ca key): %s", ssh_err(r));
+                        fatal("sshkey_from_private (ca key): %s", ssh_err(r));
 
-                if ((r = sshkey_certify(public, ca, key_type_name)) != 0)
-                        fatal("Couldn't certify key %s: %s", tmp, ssh_err(r));
+                if (agent_fd != -1 && (ca->flags & SSHKEY_FLAG_EXT) != 0) {
+                        if ((r = sshkey_certify_custom(public, ca,
+                            key_type_name, agent_signer, &agent_fd)) != 0)
+                                fatal("Couldn't certify key %s via agent: %s",
+                                    tmp, ssh_err(r));
+                } else {
+                        if ((sshkey_certify(public, ca, key_type_name)) != 0)
+                                fatal("Couldn't certify key %s: %s",
+                                    tmp, ssh_err(r));
+                }
 
                 if ((cp = strrchr(tmp, '.')) != NULL && strcmp(cp, ".pub") == 0)
                         *cp = '\0';
@@ -1789,7 +1892,8 @@ parse_cert_times(char *timespec)
 static void
 add_cert_option(char *opt)
 {
-        char *val;
+        char *val, *cp;
+        int iscrit = 0;
 
         if (strcasecmp(opt, "clear") == 0)
                 certflags_flags = 0;
@@ -1829,6 +1933,18 @@ add_cert_option(char *opt)
                 if (addr_match_cidr_list(NULL, val) != 0)
                         fatal("Invalid source-address list");
                 certflags_src_addr = xstrdup(val);
+        } else if (strncasecmp(opt, "extension:", 10) == 0 ||
+                   (iscrit = (strncasecmp(opt, "critical:", 9) == 0))) {
+                val = xstrdup(strchr(opt, ':') + 1);
+                if ((cp = strchr(val, '=')) != NULL)
+                        *cp++ = '\0';
+                cert_userext = xreallocarray(cert_userext, ncert_userext + 1,
+                    sizeof(*cert_userext));
+                cert_userext[ncert_userext].key = val;
+                cert_userext[ncert_userext].val = cp == NULL ?
+                    NULL : xstrdup(cp);
+                cert_userext[ncert_userext].crit = iscrit;
+                ncert_userext++;
         } else
                 fatal("Unsupported certificate option \"%s\"", opt);
 }
@@ -1955,7 +2071,7 @@ do_show_cert(struct passwd *pw)
                 if (*cp == '#' || *cp == '\0')
                         continue;
                 if ((key = sshkey_new(KEY_UNSPEC)) == NULL)
-                        fatal("key_new");
+                        fatal("sshkey_new");
                 if ((r = sshkey_read(key, &cp)) != 0) {
                         error("%s:%lu: invalid key: %s", path,
                             lnum, ssh_err(r));
@@ -2101,7 +2217,7 @@ update_krl_from_file(struct passwd *pw, const char *file, int wild_ca,
                                  */
                         }
                         if ((key = sshkey_new(KEY_UNSPEC)) == NULL)
-                                fatal("key_new");
+                                fatal("sshkey_new");
                         if ((r = sshkey_read(key, &cp)) != 0)
                                 fatal("%s:%lu: invalid key: %s",
                                     path, lnum, ssh_err(r));
@@ -2209,17 +2325,11 @@ do_check_krl(struct passwd *pw, int argc, char **argv)
         exit(ret);
 }
 
-#ifdef WITH_SSH1
-# define RSA1_USAGE " | rsa1"
-#else
-# define RSA1_USAGE ""
-#endif
-
 static void
 usage(void)
 {
         fprintf(stderr,
-            "usage: ssh-keygen [-q] [-b bits] [-t dsa | ecdsa | ed25519 | rsa%s]\n"
+            "usage: ssh-keygen [-q] [-b bits] [-t dsa | ecdsa | ed25519 | rsa]\n"
             "                  [-N new_passphrase] [-C comment] [-f output_keyfile]\n"
             "       ssh-keygen -p [-P old_passphrase] [-N new_passphrase] [-f keyfile]\n"
             "       ssh-keygen -i [-m key_format] [-f input_keyfile]\n"
@@ -2227,7 +2337,7 @@ usage(void)
             "       ssh-keygen -y [-f input_keyfile]\n"
             "       ssh-keygen -c [-P passphrase] [-C comment] [-f keyfile]\n"
             "       ssh-keygen -l [-v] [-E fingerprint_hash] [-f input_keyfile]\n"
-            "       ssh-keygen -B [-f input_keyfile]\n", RSA1_USAGE);
+            "       ssh-keygen -B [-f input_keyfile]\n");
 #ifdef ENABLE_PKCS11
         fprintf(stderr,
             "       ssh-keygen -D pkcs11\n");
@@ -2242,8 +2352,9 @@ usage(void)
             "       ssh-keygen -T output_file -f input_file [-v] [-a rounds] [-J num_lines]\n"
             "                  [-j start_line] [-K checkpt] [-W generator]\n"
 #endif
-            "       ssh-keygen -s ca_key -I certificate_identity [-h] [-n principals]\n"
-            "                  [-O option] [-V validity_interval] [-z serial_number] file ...\n"
+            "       ssh-keygen -s ca_key -I certificate_identity [-h] [-U]\n"
+            "                  [-D pkcs11_provider] [-n principals] [-O option]\n"
+            "                  [-V validity_interval] [-z serial_number] file ...\n"
             "       ssh-keygen -L [-f input_keyfile]\n"
             "       ssh-keygen -A\n"
             "       ssh-keygen -k -f krl_file [-u] [-s ca_public] [-z version_number]\n"
@@ -2301,8 +2412,8 @@ main(int argc, char **argv)
         if (gethostname(hostname, sizeof(hostname)) < 0)
                 fatal("gethostname: %s", strerror(errno));
 
-        /* Remaining characters: UYdw */
-        while ((opt = getopt(argc, argv, "ABHLQXceghiklopquvxy"
+        /* Remaining characters: Ydw */
+        while ((opt = getopt(argc, argv, "ABHLQUXceghiklopquvxy"
             "C:D:E:F:G:I:J:K:M:N:O:P:R:S:T:V:W:Z:"
             "a:b:f:g:j:m:n:r:s:t:z:")) != -1) {
                 switch (opt) {
@@ -2429,6 +2540,9 @@ main(int argc, char **argv)
                 case 'D':
                         pkcs11provider = optarg;
                         break;
+                case 'U':
+                        prefer_agent = 1;
+                        break;
                 case 'u':
                         update_krl = 1;
                         break;
@@ -2648,9 +2762,9 @@ main(int argc, char **argv)
                 printf("Generating public/private %s key pair.\n",
                     key_type_name);
         if ((r = sshkey_generate(type, bits, &private)) != 0)
-                fatal("key_generate failed");
+                fatal("sshkey_generate failed");
         if ((r = sshkey_from_private(private, &public)) != 0)
-                fatal("key_from_private failed: %s\n", ssh_err(r));
+                fatal("sshkey_from_private failed: %s\n", ssh_err(r));
 
         if (!have_identity)
                 ask_filename(pw, "Enter file in which to save the key");