upstream: ssh-keygen support for generating U2F/FIDO keys

OpenBSD-Commit-ID: 6ce04f2b497ac9dd8c327f76f1e6c724fb1d1b37

1 files changed, 35 insertions, 6 deletions

diff --git a/ssh-keygen.c b/ssh-keygen.c
index 27ccc15df..ad7a2b4e0 100644
--- a/ssh-keygen.c
+++ b/ssh-keygen.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: ssh-keygen.c,v 1.356 2019/10/16 06:03:30 djm Exp $ */
+/* $OpenBSD: ssh-keygen.c,v 1.357 2019/10/31 21:17:09 djm Exp $ */
 /*
  * Author: Tatu Ylonen <ylo@cs.hut.fi>
  * Copyright (c) 1994 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
@@ -63,6 +63,8 @@
 #include "utf8.h"
 #include "authfd.h"
 #include "sshsig.h"
+#include "ssh-sk.h"
+#include "sk-api.h" /* XXX for SSH_SK_USER_PRESENCE_REQD; remove */
 
 #ifdef WITH_OPENSSL
 # define DEFAULT_KEY_TYPE_NAME "rsa"
@@ -150,6 +152,9 @@ static char *key_type_name = NULL;
 /* Load key from this PKCS#11 provider */
 static char *pkcs11provider = NULL;
 
+/* FIDO/U2F provider to use */
+static char *sk_provider = NULL;
+
 /* Format for writing private keys */
 static int private_key_format = SSHKEY_PRIVATE_OPENSSH;
 
@@ -269,6 +274,10 @@ ask_filename(struct passwd *pw, const char *prompt)
                 case KEY_ECDSA:
                         name = _PATH_SSH_CLIENT_ID_ECDSA;
                         break;
+                case KEY_ECDSA_SK_CERT:
+                case KEY_ECDSA_SK:
+                        name = _PATH_SSH_CLIENT_ID_ECDSA_SK;
+                        break;
 #endif
                 case KEY_RSA_CERT:
                 case KEY_RSA:
@@ -2767,9 +2776,10 @@ main(int argc, char **argv)
         int gen_all_hostkeys = 0, gen_krl = 0, update_krl = 0, check_krl = 0;
         int prefer_agent = 0, convert_to = 0, convert_from = 0;
         int print_public = 0, print_generic = 0, cert_serial_autoinc = 0;
-        unsigned long long cert_serial = 0;
+        unsigned long long ull, cert_serial = 0;
         char *identity_comment = NULL, *ca_key_path = NULL;
         u_int32_t bits = 0;
+        uint8_t sk_flags = SSH_SK_USER_PRESENCE_REQD;
         FILE *f;
         const char *errstr;
         int log_level = SYSLOG_LEVEL_INFO;
@@ -2804,10 +2814,12 @@ main(int argc, char **argv)
         if (gethostname(hostname, sizeof(hostname)) == -1)
                 fatal("gethostname: %s", strerror(errno));
 
-        /* Remaining characters: dw */
+        sk_provider = getenv("SSH_SK_PROVIDER");
+
+        /* Remaining character: d */
         while ((opt = getopt(argc, argv, "ABHLQUXceghiklopquvxy"
             "C:D:E:F:G:I:J:K:M:N:O:P:R:S:T:V:W:Y:Z:"
-            "a:b:f:g:j:m:n:r:s:t:z:")) != -1) {
+            "a:b:f:g:j:m:n:r:s:t:w:x:z:")) != -1) {
                 switch (opt) {
                 case 'A':
                         gen_all_hostkeys = 1;
@@ -2907,7 +2919,6 @@ main(int argc, char **argv)
                         quiet = 1;
                         break;
                 case 'e':
-                case 'x':
                         /* export key */
                         convert_to = 1;
                         break;
@@ -2964,6 +2975,19 @@ main(int argc, char **argv)
                         break;
                 case 'Y':
                         sign_op = optarg;
+                case 'w':
+                        sk_provider = optarg;
+                        break;
+                case 'x':
+                        if (*optarg == '\0')
+                                fatal("Missing security key flags");
+                        ull = strtoull(optarg, &ep, 0);
+                        if (*ep != '\0')
+                                fatal("Security key flags \"%s\" is not a "
+                                    "number", optarg);
+                        if (ull > 0xff)
+                                fatal("Invalid security key flags 0x%llx", ull);
+                        sk_flags = (uint8_t)ull;
                         break;
                 case 'z':
                         errno = 0;
@@ -3221,7 +3245,12 @@ main(int argc, char **argv)
         if (!quiet)
                 printf("Generating public/private %s key pair.\n",
                     key_type_name);
-        if ((r = sshkey_generate(type, bits, &private)) != 0)
+        if (type == KEY_ECDSA_SK) {
+                if (sshsk_enroll(sk_provider,
+                    cert_key_id == NULL ? "ssh:" : cert_key_id,
+                    sk_flags, NULL, &private, NULL) != 0)
+                        exit(1); /* error message already printed */
+        } else if ((r = sshkey_generate(type, bits, &private)) != 0)
                 fatal("sshkey_generate failed");
         if ((r = sshkey_from_private(private, &public)) != 0)
                 fatal("sshkey_from_private failed: %s\n", ssh_err(r));