- djm@cvs.openbsd.org 2010/06/29 23:15:30

     [ssh-keygen.1 ssh-keygen.c]
     allow import (-i) and export (-e) of PEM and PKCS#8 encoded keys;
     bz#1749; ok markus@

3 files changed, 266 insertions, 66 deletions

diff --git a/ChangeLog b/ChangeLog
index 20b39f0de..ee40f10eb 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -6,6 +6,10 @@
    - djm@cvs.openbsd.org 2010/06/26 23:04:04
      [ssh.c]
      oops, forgot to #include <canohost.h>; spotted and patch from chl@
+   - djm@cvs.openbsd.org 2010/06/29 23:15:30
+     [ssh-keygen.1 ssh-keygen.c]
+     allow import (-i) and export (-e) of PEM and PKCS#8 encoded keys;
+     bz#1749; ok markus@
 
 20100627
  - (tim) [openbsd-compat/port-uw.c] Reorder includes. auth-options.h now needs
diff --git a/ssh-keygen.1 b/ssh-keygen.1
index 26ae31f5e..0d62255ba 100644
--- a/ssh-keygen.1
+++ b/ssh-keygen.1
@@ -1,4 +1,4 @@
-.\"     $OpenBSD: ssh-keygen.1,v 1.94 2010/04/16 06:47:04 jmc Exp $
+.\"     $OpenBSD: ssh-keygen.1,v 1.95 2010/06/29 23:15:30 djm Exp $
 .\"
 .\"  -*- nroff -*-
 .\"
@@ -37,7 +37,7 @@
 .\" (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: April 16 2010 $
+.Dd $Mdocdate: June 29 2010 $
 .Dt SSH-KEYGEN 1
 .Os
 .Sh NAME
@@ -59,9 +59,11 @@
 .Op Fl f Ar keyfile
 .Nm ssh-keygen
 .Fl i
+.Op Fl m Ar key_format
 .Op Fl f Ar input_keyfile
 .Nm ssh-keygen
 .Fl e
+.Op Fl m Ar key_format
 .Op Fl f Ar input_keyfile
 .Nm ssh-keygen
 .Fl y
@@ -215,11 +217,13 @@ Download the RSA public keys provided by the PKCS#11 shared library
 .Ar pkcs11 .
 .It Fl e
 This option will read a private or public OpenSSH key file and
-print the key in
-RFC 4716 SSH Public Key File Format
-to stdout.
-This option allows exporting keys for use by several commercial
-SSH implementations.
+print to stdout the key in one of the formats specified by the
+.Fl m
+option.
+The default export format is
+.Dq RFC4716 .
+This option allows exporting OpenSSH key for use by other programs, including
+several commercial SSH implementations.
 .It Fl F Ar hostname
 Search for the specified
 .Ar hostname
@@ -270,13 +274,14 @@ Please see the
 section for details.
 .It Fl i
 This option will read an unencrypted private (or public) key file
-in SSH2-compatible format and print an OpenSSH compatible private
+in the format specified by the
+.Fl m
+option and print an OpenSSH compatible private
 (or public) key to stdout.
-.Nm
-also reads the
-RFC 4716 SSH Public Key File Format.
-This option allows importing keys from several commercial
-SSH implementations.
+This option allows importing keys from other software, including several
+commercial SSH implementations.
+The default import format is
+.Dq RFC4716 .
 .It Fl L
 Prints the contents of a certificate.
 .It Fl l
@@ -288,6 +293,22 @@ tries to find the matching public key file and prints its fingerprint.
 If combined with
 .Fl v ,
 an ASCII art representation of the key is supplied with the fingerprint.
+.It Fl m Ar key_format
+Specify a key format for the
+.Fl i
+(import) or
+.Fl e
+(export) coversion options.
+The supported key formats are:
+.Dq RFC4716
+(RFC4716/SSH2 public or private key),
+.Dq PKCS8
+(PEM PKCS8 public key)
+or
+.Dq PEM
+(PEM public key).
+The default conversion format is
+.Dq RFC4716 .
 .It Fl M Ar memory
 Specify the amount of memory to use (in megabytes) when generating
 candidate moduli for DH-GEX.
diff --git a/ssh-keygen.c b/ssh-keygen.c
index de7c4409d..be08fbda6 100644
--- a/ssh-keygen.c
+++ b/ssh-keygen.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: ssh-keygen.c,v 1.192 2010/06/23 02:59:02 djm Exp $ */
+/* $OpenBSD: ssh-keygen.c,v 1.193 2010/06/29 23:15:30 djm Exp $ */
 /*
  * Author: Tatu Ylonen <ylo@cs.hut.fi>
  * Copyright (c) 1994 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
@@ -133,14 +133,20 @@ u_int32_t certflags_flags = CERTOPT_DEFAULT;
 char *certflags_command = NULL;
 char *certflags_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;
+/* 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;
 
+
 /* argv0 */
 extern char *__progname;
 
@@ -215,30 +221,12 @@ 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);
@@ -259,6 +247,81 @@ 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);
@@ -396,24 +459,16 @@ 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);
-        }
         if ((fp = fopen(identity_file, "r")) == NULL)
                 fatal("%s: %s: %s", __progname, identity_file, strerror(errno));
         encoded[0] = '\0';
@@ -423,7 +478,7 @@ 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;
                         }
@@ -448,26 +503,130 @@ 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;
+        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);
 }
 
@@ -1525,7 +1684,7 @@ 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");
@@ -1533,9 +1692,10 @@ 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 key_fmt  Conversion format for -e/-i (PEM|PKCS8|RFC4716).\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, "  -N phrase   Provide new passphrase.\n");
@@ -1603,7 +1763,7 @@ main(int argc, char **argv)
                 exit(1);
         }
 
-        while ((opt = getopt(argc, argv, "degiqpclBHLhvxXyF:b:f:t:D:I:P:N:n:"
+        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':
@@ -1635,6 +1795,21 @@ 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;
@@ -1671,7 +1846,7 @@ 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;
@@ -1680,7 +1855,7 @@ main(int argc, char **argv)
                 case 'i':
                 case 'X':
                         /* import key */
-                        convert_from_ssh2 = 1;
+                        convert_from = 1;
                         break;
                 case 'y':
                         print_public = 1;
@@ -1796,10 +1971,10 @@ 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) {