3 files changed, 157 insertions, 30 deletions

diff --git a/ChangeLog b/ChangeLog
index 8a7083236..9e59adf1a 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -18,6 +18,14 @@
      [ssh-keyscan.c]
      use timerclear macro
      ok djm@
+   - stevesk@cvs.openbsd.org 2011/03/23 15:16:22
+     [ssh-keygen.1 ssh-keygen.c]
+     Add -A option.  For each of the key types (rsa1, rsa, dsa and ecdsa)
+     for which host keys do not exist, generate the host keys with the
+     default key file path, an empty passphrase, default bits for the key
+     type, and default comment.  This will be used by /etc/rc to generate
+     new host keys.  Idea from deraadt.
+     ok deraadt
 
 20110221
  - (dtucker) [contrib/cygwin/ssh-host-config] From Corinna: revamp of the
diff --git a/ssh-keygen.1 b/ssh-keygen.1
index 205f741b8..2573087b3 100644
--- a/ssh-keygen.1
+++ b/ssh-keygen.1
@@ -1,4 +1,4 @@
-.\"     $OpenBSD: ssh-keygen.1,v 1.101 2010/10/28 18:33:28 jmc Exp $
+.\"     $OpenBSD: ssh-keygen.1,v 1.102 2011/03/23 15:16:22 stevesk Exp $
 .\"
 .\" Author: Tatu Ylonen <ylo@cs.hut.fi>
 .\" Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
@@ -35,7 +35,7 @@
 .\" (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 .\" THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 .\"
-.Dd $Mdocdate: October 28 2010 $
+.Dd $Mdocdate: March 23 2011 $
 .Dt SSH-KEYGEN 1
 .Os
 .Sh NAME
@@ -117,6 +117,8 @@
 .Nm ssh-keygen
 .Fl L
 .Op Fl f Ar input_keyfile
+.Nm ssh-keygen
+.Fl A
 .Ek
 .Sh DESCRIPTION
 .Nm
@@ -192,6 +194,13 @@ should be placed to be activated.
 .Pp
 The options are as follows:
 .Bl -tag -width Ds
+.It Fl A
+For each of the key types (rsa1, rsa, dsa and ecdsa) for which host keys
+do not exist, generate the host keys with the default key file path,
+an empty passphrase, default bits for the key type, and default comment.
+This is used by 
+.Pa /etc/rc
+to generate new host keys.
 .It Fl a Ar trials
 Specifies the number of primality tests to perform when screening DH-GEX
 candidates using the
diff --git a/ssh-keygen.c b/ssh-keygen.c
index d379b1a2c..aae33e308 100644
--- a/ssh-keygen.c
+++ b/ssh-keygen.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: ssh-keygen.c,v 1.205 2011/01/11 06:13:10 djm Exp $ */
+/* $OpenBSD: ssh-keygen.c,v 1.206 2011/03/23 15:16:22 stevesk Exp $ */
 /*
  * Author: Tatu Ylonen <ylo@cs.hut.fi>
  * Copyright (c) 1994 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
@@ -160,6 +160,38 @@ int gen_candidates(FILE *, u_int32_t, u_int32_t, BIGNUM *);
 int prime_test(FILE *, FILE *, u_int32_t, u_int32_t);
 
 static void
+type_bits_valid(int type, u_int32_t *bits)
+{
+        u_int maxbits;
+
+        if (type == KEY_UNSPEC) {
+                fprintf(stderr, "unknown key type %s\n", key_type_name);
+                exit(1);
+        }
+        if (*bits == 0) {
+                if (type == KEY_DSA)
+                        *bits = DEFAULT_BITS_DSA;
+                else if (type == KEY_ECDSA)
+                        *bits = DEFAULT_BITS_ECDSA;
+                else
+                        *bits = 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");
+        else if (type != KEY_ECDSA && *bits < 768)
+                fatal("Key must at least be 768 bits");
+        else if (type == KEY_ECDSA && key_ecdsa_bits_to_nid(*bits) == -1)
+                fatal("Invalid ECDSA key length - valid lengths are "
+                    "256, 384 or 521 bits");
+}
+
+static void
 ask_filename(struct passwd *pw, const char *prompt)
 {
         char buf[1024];
@@ -818,6 +850,98 @@ do_fingerprint(struct passwd *pw)
 }
 
 static void
+do_gen_all_hostkeys(struct passwd *pw)
+{
+        struct {
+                char *key_type;
+                char *key_type_display;
+                char *path;
+        } key_types[] = {
+                { "rsa1", "RSA1", _PATH_HOST_KEY_FILE },
+                { "rsa", "RSA" ,_PATH_HOST_RSA_KEY_FILE },
+                { "dsa", "DSA", _PATH_HOST_DSA_KEY_FILE },
+                { "ecdsa", "ECDSA",_PATH_HOST_ECDSA_KEY_FILE },
+                { NULL, NULL, NULL }
+        };
+
+        int first = 0;
+        struct stat st;
+        Key *private, *public;
+        char comment[1024];
+        int i, type, fd;
+        FILE *f;
+
+        for (i = 0; key_types[i].key_type; i++) {
+                if (stat(key_types[i].path, &st) == 0)
+                        continue;
+                if (errno != ENOENT) {
+                        printf("Could not stat %s: %s", key_types[i].path,
+                            strerror(errno));
+                        first = 0;
+                        continue;
+                }
+
+                if (first == 0) {
+                        first = 1;
+                        printf("%s: generating new host keys: ", __progname);
+                }
+                printf("%s ", key_types[i].key_type_display);
+                fflush(stdout);
+                arc4random_stir();
+                type = key_type_from_name(key_types[i].key_type);
+                strlcpy(identity_file, key_types[i].path, sizeof(identity_file));
+                bits = 0;
+                type_bits_valid(type, &bits);
+                private = key_generate(type, bits);
+                if (private == NULL) {
+                        fprintf(stderr, "key_generate failed\n");
+                        first = 0;
+                        continue;
+                }
+                public  = key_from_private(private);
+                snprintf(comment, sizeof comment, "%s@%s", pw->pw_name,
+                    hostname);
+                if (!key_save_private(private, identity_file, "", comment)) {
+                        printf("Saving the key failed: %s.\n", identity_file);
+                        key_free(private);
+                        key_free(public);
+                        first = 0;
+                        continue;
+                }
+                key_free(private);
+                arc4random_stir();
+                strlcat(identity_file, ".pub", sizeof(identity_file));
+                fd = open(identity_file, O_WRONLY | O_CREAT | O_TRUNC, 0644);
+                if (fd == -1) {
+                        printf("Could not save your public key in %s\n",
+                            identity_file);
+                        key_free(public);
+                        first = 0;
+                        continue;
+                }
+                f = fdopen(fd, "w");
+                if (f == NULL) {
+                        printf("fdopen %s failed\n", identity_file);
+                        key_free(public);
+                        first = 0;
+                        continue;
+                }
+                if (!key_write(public, f)) {
+                        fprintf(stderr, "write key failed\n");
+                        key_free(public);
+                        first = 0;
+                        continue;
+                }
+                fprintf(f, " %s\n", comment);
+                fclose(f);
+                key_free(public);
+
+        }
+        if (first != 0)
+                printf("\n");
+}
+
+static void
 printhost(FILE *f, const char *name, Key *public, int ca, int hash)
 {
         if (print_fingerprint) {
@@ -1745,6 +1869,7 @@ usage(void)
 {
         fprintf(stderr, "usage: %s [options]\n", __progname);
         fprintf(stderr, "Options:\n");
+        fprintf(stderr, "  -A          Generate non-existent host keys for all key types.\n");
         fprintf(stderr, "  -a trials   Number of trials for screening DH-GEX moduli.\n");
         fprintf(stderr, "  -B          Show bubblebabble digest of key file.\n");
         fprintf(stderr, "  -b bits     Number of bits in the key to create.\n");
@@ -1799,9 +1924,9 @@ main(int argc, char **argv)
         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;
+        int gen_all_hostkeys = 0;
         BIGNUM *start = NULL;
         FILE *f;
         const char *errstr;
@@ -1830,9 +1955,12 @@ main(int argc, char **argv)
                 exit(1);
         }
 
-        while ((opt = getopt(argc, argv, "degiqpclBHLhvxXyF:b:f:t:D:I:P:m:N:n:"
+        while ((opt = getopt(argc, argv, "AdegiqpclBHLhvxXyF: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 'A':
+                        gen_all_hostkeys = 1;
+                        break;
                 case 'b':
                         bits = (u_int32_t)strtonum(optarg, 256, 32768, &errstr);
                         if (errstr)
@@ -2108,37 +2236,19 @@ main(int argc, char **argv)
                 return (0);
         }
 
+        if (gen_all_hostkeys) {
+                do_gen_all_hostkeys(pw);
+                return (0);
+        }
+
         arc4random_stir();
 
         if (key_type_name == NULL)
                 key_type_name = "rsa";
 
         type = key_type_from_name(key_type_name);
-        if (type == KEY_UNSPEC) {
-                fprintf(stderr, "unknown key type %s\n", key_type_name);
-                exit(1);
-        }
-        if (bits == 0) {
-                if (type == KEY_DSA)
-                        bits = DEFAULT_BITS_DSA;
-                else if (type == KEY_ECDSA)
-                        bits = DEFAULT_BITS_ECDSA;
-                else
-                        bits = 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");
-        else if (type != KEY_ECDSA && bits < 768)
-                fatal("Key must at least be 768 bits");
-        else if (type == KEY_ECDSA && key_ecdsa_bits_to_nid(bits) == -1)
-                fatal("Invalid ECDSA key length - valid lengths are "
-                    "256, 384 or 521 bits");
+        type_bits_valid(type, &bits);
+
         if (!quiet)
                 printf("Generating public/private %s key pair.\n", key_type_name);
         private = key_generate(type, bits);