Added a framework for importing foreign key formats, and implemented

importing of OpenSSH SSH2 private key files (both encrypted and
unencrypted). Seems to work fine.

[originally from svn r1668]

Recipe

@@ -128,4 +128,4 @@ pageant  : [G] pageant sshrsa sshpubk sshdes sshbn sshmd5 version tree234
 
 puttygen : [G] puttygen sshrsag sshdssg sshprime sshdes sshbn sshmd5 version
          + sshrand noise sshsha winstore misc winctrls sshrsa sshdss
-         + sshpubk sshaes sshsh512 puttygen.res LIBS
+         + sshpubk sshaes sshsh512 import puttygen.res LIBS

doc/faq.but

@@ -1,4 +1,4 @@
-\versionid $Id: faq.but,v 1.24 2002/04/01 15:18:29 simon Exp $
+\versionid $Id: faq.but,v 1.25 2002/05/11 16:45:29 simon Exp $
 
 \A{faq} PuTTY FAQ
 
@@ -37,10 +37,10 @@ version 0.52.
 \S{faq-ssh2-keyfmt}{Question} Does PuTTY support reading OpenSSH or
 \cw{ssh.com} SSHv2 private key files?
 
-Not at present. OpenSSH and \cw{ssh.com} have totally different
+Version 0.52 doesn't, but in the latest development snapshots
-formats for private key files, and neither one is particularly
+PuTTYgen can load OpenSSH private keys. We plan to add an export
-pleasant, so PuTTY has its own. We do plan to write a converter at
+feature so that it can save them as well, and we also plan to
-some stage.
+support the \cw{ssh.com} key format.
 
 \S{faq-ssh1}{Question} Does PuTTY support SSH v1?
 

doc/pubkey.but

@@ -1,4 +1,4 @@
-\versionid $Id: pubkey.but,v 1.13 2001/12/14 09:58:07 simon Exp $
+\versionid $Id: pubkey.but,v 1.14 2002/05/11 16:45:29 simon Exp $
 
 \C{pubkey} Using public keys for SSH authentication
 
@@ -63,6 +63,8 @@ supported by PuTTY are described in \k{puttygen-keytype}.
 
 \H{pubkey-puttygen} Using PuTTYgen, the PuTTY key generator
 
+\cfg{winhelp-topic}{puttygen.general}
+
 PuTTYgen is a key generator. It generates pairs of public and private
 keys to be used with PuTTY, PSCP, and Plink, as well as the PuTTY
 authentication agent, Pageant (see \k{pageant}).  PuTTYgen generates

import.c

@@ -0,0 +1,495 @@
+/*
+ * Code for PuTTY to import and export private key files in other
+ * SSH clients' formats.
+ */
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <assert.h>
+#include <ctype.h>
+
+#include "ssh.h"
+#include "misc.h"
+
+#define PUT_32BIT(cp, value) do { \
+  (cp)[3] = (value); \
+  (cp)[2] = (value) >> 8; \
+  (cp)[1] = (value) >> 16; \
+  (cp)[0] = (value) >> 24; } while (0)
+
+#define GET_32BIT(cp) \
+    (((unsigned long)(unsigned char)(cp)[0] << 24) | \
+    ((unsigned long)(unsigned char)(cp)[1] << 16) | \
+    ((unsigned long)(unsigned char)(cp)[2] << 8) | \
+    ((unsigned long)(unsigned char)(cp)[3]))
+
+int openssh_encrypted(char *filename);
+struct ssh2_userkey *openssh_read(char *filename, char *passphrase);
+
+/*
+ * Given a key type, determine whether we know how to import it.
+ */
+int import_possible(int type)
+{
+    if (type == SSH_KEYTYPE_OPENSSH)
+	return 1;
+    return 0;
+}
+
+/*
+ * Given a key type, determine what native key type
+ * (SSH_KEYTYPE_SSH1 or SSH_KEYTYPE_SSH2) it will come out as once
+ * we've imported it.
+ */
+int import_target_type(int type)
+{
+    /*
+     * There are no known foreign SSH1 key formats.
+     */
+    return SSH_KEYTYPE_SSH2;
+}
+
+/*
+ * Determine whether a foreign key is encrypted.
+ */
+int import_encrypted(char *filename, int type, char **comment)
+{
+    if (type == SSH_KEYTYPE_OPENSSH) {
+	*comment = filename;	       /* OpenSSH doesn't do key comments */
+	return openssh_encrypted(filename);
+    }
+    return 0;
+}
+
+/*
+ * Import an SSH1 key.
+ */
+int import_ssh1(char *filename, int type, struct RSAKey *key, char *passphrase)
+{
+    return 0;
+}
+
+/*
+ * Import an SSH2 key.
+ */
+struct ssh2_userkey *import_ssh2(char *filename, int type, char *passphrase)
+{
+    if (type == SSH_KEYTYPE_OPENSSH)
+	return openssh_read(filename, passphrase);
+    return NULL;
+}
+
+/* ----------------------------------------------------------------------
+ * Helper routines. (The base64 ones are defined in sshpubk.c.)
+ */
+
+#define isbase64(c) (    ((c) >= 'A' && (c) <= 'Z') || \
+                         ((c) >= 'a' && (c) <= 'z') || \
+                         ((c) >= '0' && (c) <= '9') || \
+                         (c) == '+' || (c) == '/' || (c) == '=' \
+                         )
+
+extern int base64_decode_atom(char *atom, unsigned char *out);
+extern int base64_lines(int datalen);
+extern void base64_encode_atom(unsigned char *data, int n, char *out);
+extern void base64_encode(FILE * fp, unsigned char *data, int datalen);
+
+/*
+ * Read an ASN.1/BER identifier and length pair.
+ * 
+ * Flags are a combination of the #defines listed below.
+ * 
+ * Returns -1 if unsuccessful; otherwise returns the number of
+ * bytes used out of the source data.
+ */
+
+/* ASN.1 tag classes. */
+#define ASN1_CLASS_UNIVERSAL        (0 << 6)
+#define ASN1_CLASS_APPLICATION      (1 << 6)
+#define ASN1_CLASS_CONTEXT_SPECIFIC (2 << 6)
+#define ASN1_CLASS_PRIVATE          (3 << 6)
+#define ASN1_CLASS_MASK             (3 << 6)
+
+/* Primitive versus constructed bit. */
+#define ASN1_CONSTRUCTED            (1 << 5)
+
+int ber_read_id_len(void *source, int sourcelen,
+		    int *id, int *length, int *flags)
+{
+    unsigned char *p = (unsigned char *) source;
+
+    if (sourcelen == 0)
+	return -1;
+
+    *flags = (*p & 0xE0);
+    if ((*p & 0x1F) == 0x1F) {
+	*id = 0;
+	while (*p & 0x80) {
+	    *id = (*id << 7) | (*p & 0x7F);
+	    p++, sourcelen--;
+	    if (sourcelen == 0)
+		return -1;
+	}
+	*id = (*id << 7) | (*p & 0x7F);
+	p++, sourcelen--;
+    } else {
+	*id = *p & 0x1F;
+	p++, sourcelen--;
+    }
+
+    if (sourcelen == 0)
+	return -1;
+
+    if (*p & 0x80) {
+	int n = *p & 0x7F;
+	p++, sourcelen--;
+	if (sourcelen < n)
+	    return -1;
+	*length = 0;
+	while (n--)
+	    *length = (*length << 8) | (*p++);
+	sourcelen -= n;
+    } else {
+	*length = *p;
+	p++, sourcelen--;
+    }
+
+    return p - (unsigned char *) source;
+}
+
+/* ----------------------------------------------------------------------
+ * Code to read OpenSSH private keys.
+ */
+
+enum { OSSH_DSA, OSSH_RSA };
+struct openssh_key {
+    int type;
+    int encrypted;
+    char iv[32];
+    unsigned char *keyblob;
+    int keyblob_len, keyblob_size;
+};
+
+struct openssh_key *load_openssh_key(char *filename)
+{
+    struct openssh_key *ret;
+    FILE *fp;
+    char buffer[256];
+    char *errmsg, *p;
+    int headers_done;
+
+    ret = smalloc(sizeof(*ret));
+    ret->keyblob = NULL;
+    ret->keyblob_len = ret->keyblob_size = 0;
+    ret->encrypted = 0;
+    memset(ret->iv, 0, sizeof(ret->iv));
+
+    fp = fopen(filename, "r");
+    if (!fp) {
+	errmsg = "Unable to open key file";
+	goto error;
+    }
+    if (!fgets(buffer, sizeof(buffer), fp) ||
+	0 != strncmp(buffer, "-----BEGIN ", 11) ||
+	0 != strcmp(buffer+strlen(buffer)-17, "PRIVATE KEY-----\n")) {
+	errmsg = "File does not begin with OpenSSH key header";
+	goto error;
+    }
+    if (!strcmp(buffer, "-----BEGIN RSA PRIVATE KEY-----\n"))
+	ret->type = OSSH_RSA;
+    else if (!strcmp(buffer, "-----BEGIN DSA PRIVATE KEY-----\n"))
+	ret->type = OSSH_DSA;
+    else {
+	errmsg = "Unrecognised key type";
+	goto error;
+    }
+
+    headers_done = 0;
+    while (1) {
+	if (!fgets(buffer, sizeof(buffer), fp)) {
+	    errmsg = "Unexpected end of file";
+	    goto error;
+	}
+	if (0 == strncmp(buffer, "-----END ", 9) &&
+	    0 == strcmp(buffer+strlen(buffer)-17, "PRIVATE KEY-----\n"))
+	    break;		       /* done */
+	if ((p = strchr(buffer, ':')) != NULL) {
+	    if (headers_done) {
+		errmsg = "Header found in body of key data";
+		goto error;
+	    }
+	    *p++ = '\0';
+	    while (*p && isspace((unsigned char)*p)) p++;
+	    if (!strcmp(buffer, "Proc-Type")) {
+		if (p[0] != '4' || p[1] != ',') {
+		    errmsg = "Proc-Type is not 4 (only 4 is supported)";
+		    goto error;
+		}
+		p += 2;
+		if (!strcmp(p, "ENCRYPTED\n"))
+		    ret->encrypted = 1;
+	    } else if (!strcmp(buffer, "DEK-Info")) {
+		int i, j;
+
+		if (strncmp(p, "DES-EDE3-CBC,", 13)) {
+		    errmsg = "Ciphers other than DES-EDE3-CBC not supported";
+		    goto error;
+		}
+		p += 13;
+		for (i = 0; i < 8; i++) {
+		    if (1 != sscanf(p, "%2x", &j))
+			break;
+		    ret->iv[i] = j;
+		    p += 2;
+		}
+		if (i < 8) {
+		    errmsg = "Expected 16-digit iv in DEK-Info";
+		    goto error;
+		}
+	    }
+	} else {
+	    headers_done = 1;
+
+	    p = buffer;
+	    while (isbase64(p[0]) && isbase64(p[1]) &&
+		   isbase64(p[2]) && isbase64(p[3])) {
+		int len;
+		unsigned char out[3];
+
+		len = base64_decode_atom(p, out);
+
+		if (len <= 0) {
+		    errmsg = "Invalid base64 encoding";
+		    goto error;
+		}
+
+		if (ret->keyblob_len + len > ret->keyblob_size) {
+		    ret->keyblob_size = ret->keyblob_len + len + 256;
+		    ret->keyblob = srealloc(ret->keyblob, ret->keyblob_size);
+		}
+
+		memcpy(ret->keyblob + ret->keyblob_len, out, len);
+		ret->keyblob_len += len;
+
+		p += 4;
+	    }
+
+	    if (isbase64(*p)) {
+		errmsg = "base64 characters left at end of line";
+		goto error;
+	    }
+	}
+    }
+
+    if (ret->keyblob_len == 0 || !ret->keyblob) {
+	errmsg = "Key body not present";
+	goto error;
+    }
+
+    if (ret->encrypted && ret->keyblob_len % 8 != 0) {
+	errmsg = "Encrypted key blob is not a multiple of cipher block size";
+	goto error;
+    }
+
+    return ret;
+
+    error:
+    if (ret) {
+	if (ret->keyblob) sfree(ret->keyblob);
+	sfree(ret);
+    }
+    return NULL;
+}
+
+int openssh_encrypted(char *filename)
+{
+    struct openssh_key *key = load_openssh_key(filename);
+    int ret;
+
+    if (!key)
+	return 0;
+    ret = key->encrypted;
+    sfree(key->keyblob);
+    sfree(key);
+    return ret;
+}
+
+struct ssh2_userkey *openssh_read(char *filename, char *passphrase)
+{
+    struct openssh_key *key = load_openssh_key(filename);
+    struct ssh2_userkey *retkey;
+    unsigned char *p;
+    int ret, id, len, flags;
+    int i, num_integers;
+    struct ssh2_userkey *retval = NULL;
+    char *errmsg;
+    unsigned char *blob;
+    int blobptr, privptr;
+    char *modptr;
+    int modlen;
+
+    if (!key)
+	return NULL;
+
+    if (key->encrypted) {
+	/*
+	 * Derive encryption key from passphrase and iv/salt:
+	 * 
+	 *  - let block A equal MD5(passphrase || iv)
+	 *  - let block B equal MD5(A || passphrase || iv)
+	 *  - block C would be MD5(B || passphrase || iv) and so on
+	 *  - encryption key is the first N bytes of A || B
+	 */
+	struct MD5Context md5c;
+	unsigned char keybuf[32];
+
+	MD5Init(&md5c);
+	MD5Update(&md5c, passphrase, strlen(passphrase));
+	MD5Update(&md5c, key->iv, 8);
+	MD5Final(keybuf, &md5c);
+
+	MD5Init(&md5c);
+	MD5Update(&md5c, keybuf, 16);
+	MD5Update(&md5c, passphrase, strlen(passphrase));
+	MD5Update(&md5c, key->iv, 8);
+	MD5Final(keybuf+16, &md5c);
+
+	/*
+	 * Now decrypt the key blob.
+	 */
+	des3_decrypt_pubkey_ossh(keybuf, key->iv,
+				 key->keyblob, key->keyblob_len);
+    }
+
+    /*
+     * Now we have a decrypted key blob, which contains an ASN.1
+     * encoded private key. We must now untangle the ASN.1.
+     *
+     * We expect the whole key blob to be formatted as a SEQUENCE
+     * (0x30 followed by a length code indicating that the rest of
+     * the blob is part of the sequence). Within that SEQUENCE we
+     * expect to see a bunch of INTEGERs. What those integers mean
+     * depends on the key type:
+     *
+     *  - For RSA, we expect the integers to be 0, n, e, d, p, q,
+     *    dmp1, dmq1, iqmp in that order. (The last three are d mod
+     *    (p-1), d mod (q-1), inverse of q mod p respectively.)
+     *
+     *  - For DSA, we expect them to be 0, p, q, g, y, x in that
+     *    order.
+     */
+    
+    p = key->keyblob;
+
+    /* Expect the SEQUENCE header. Take its absence as a failure to decrypt. */
+    ret = ber_read_id_len(p, key->keyblob_len, &id, &len, &flags);
+    p += ret;
+    if (ret < 0 || id != 16) {
+	errmsg = "ASN.1 decoding failure";
+	retval = SSH2_WRONG_PASSPHRASE;
+	goto error;
+    }
+
+    /* Expect a load of INTEGERs. */
+    if (key->type == OSSH_RSA)
+	num_integers = 9;
+    else if (key->type == OSSH_DSA)
+	num_integers = 6;
+
+    /*
+     * Space to create key blob in.
+     */
+    blob = smalloc(256+key->keyblob_len);
+    PUT_32BIT(blob, 7);
+    if (key->type == OSSH_DSA)
+	memcpy(blob+4, "ssh-dss", 7);
+    else if (key->type == OSSH_RSA)
+	memcpy(blob+4, "ssh-rsa", 7);
+    blobptr = 4+7;
+    privptr = -1;
+
+    for (i = 0; i < num_integers; i++) {
+	ret = ber_read_id_len(p, key->keyblob+key->keyblob_len-p,
+			      &id, &len, &flags);
+	p += ret;
+	if (ret < 0 || id != 2 ||
+	    key->keyblob+key->keyblob_len-p < len) {
+	    errmsg = "ASN.1 decoding failure";
+	    goto error;
+	}
+
+	if (i == 0) {
+	    /*
+	     * The first integer should be zero always (I think
+	     * this is some sort of version indication).
+	     */
+	    if (len != 1 || p[0] != 0) {
+		errmsg = "Version number mismatch";
+		goto error;
+	    }
+	} else if (key->type == OSSH_RSA) {
+	    /*
+	     * Integers 1 and 2 go into the public blob but in the
+	     * opposite order; integers 3, 4, 5 and 8 go into the
+	     * private blob. The other two (6 and 7) are ignored.
+	     */
+	    if (i == 1) {
+		/* Save the details for after we deal with number 2. */
+		modptr = p;
+		modlen = len;
+	    } else if (i != 6 && i != 7) {
+		PUT_32BIT(blob+blobptr, len);
+		memcpy(blob+blobptr+4, p, len);
+		blobptr += 4+len;
+		if (i == 2) {
+		    PUT_32BIT(blob+blobptr, modlen);
+		    memcpy(blob+blobptr+4, modptr, modlen);
+		    blobptr += 4+modlen;
+		    privptr = blobptr;
+		}
+	    }
+	} else if (key->type == OSSH_DSA) {
+	    /*
+	     * Integers 1-4 go into the public blob; integer 5 goes
+	     * into the private blob.
+	     */
+	    PUT_32BIT(blob+blobptr, len);
+	    memcpy(blob+blobptr+4, p, len);
+	    blobptr += 4+len;
+	    if (i == 4)
+		privptr = blobptr;
+	}
+
+	/* Skip past the number. */
+	p += len;
+    }
+
+    /*
+     * Now put together the actual key. Simplest way to do this is
+     * to assemble our own key blobs and feed them to the createkey
+     * functions; this is a bit faffy but it does mean we get all
+     * the sanity checks for free.
+     */
+    assert(privptr > 0);	       /* should have bombed by now if not */
+    retkey = smalloc(sizeof(struct ssh2_userkey));
+    retkey->alg = (key->type == OSSH_RSA ? &ssh_rsa : &ssh_dss);
+    retkey->data = retkey->alg->createkey(blob, privptr,
+					  blob+privptr, blobptr-privptr);
+    if (!retkey->data) {
+	sfree(retkey);
+	errmsg = "unable to create key data structure";
+	goto error;
+    }
+
+    retkey->comment = dupstr("imported-openssh-key");
+    if (blob) sfree(blob);
+    sfree(key->keyblob);
+    sfree(key);
+    return retkey;
+
+    error:
+    if (blob) sfree(blob);
+    sfree(key->keyblob);
+    sfree(key);
+    return retval;
+}

puttygen.c

@@ -501,6 +501,8 @@ static int CALLBACK MainDlgProc(HWND hwnd, UINT msg,
 	IDC_TYPESTATIC, IDC_KEYSSH1, IDC_KEYSSH2RSA, IDC_KEYSSH2DSA,
 	IDC_BITSSTATIC, IDC_BITS,
 	IDC_ABOUT,
+	IDC_GIVEHELP,
+	IDC_IMPORT, IDC_EXPORT_OPENSSH, IDC_EXPORT_SSHCOM
     };
     static const int nokey_ids[] = { IDC_NOKEY, 0 };
     static const int generating_ids[] =
@@ -531,6 +533,44 @@ static int CALLBACK MainDlgProc(HWND hwnd, UINT msg,
         }
         requested_help = FALSE;
 
+	{
+	    HMENU menu, menu1;
+
+	    menu = CreateMenu();
+
+	    menu1 = CreateMenu();
+	    AppendMenu(menu1, MF_ENABLED, IDC_GENERATE, "&Generate key pair");
+	    AppendMenu(menu1, MF_ENABLED, IDC_LOAD, "&Load private key");
+	    AppendMenu(menu1, MF_ENABLED, IDC_SAVEPUB, "Save p&ublic key");
+	    AppendMenu(menu1, MF_ENABLED, IDC_SAVE, "&Save private key");
+
+	    AppendMenu(menu, MF_POPUP | MF_ENABLED, (UINT) menu1, "&File");
+
+#if 0
+	    /*
+	     * Exporting not yet supported, but when we do it we
+	     * should just put this lot back in.
+	     */
+	    menu1 = CreateMenu();
+	    AppendMenu(menu1, MF_ENABLED, IDC_EXPORT_OPENSSH,
+		       "Export &OpenSSH key");
+	    AppendMenu(menu1, MF_ENABLED, IDC_EXPORT_SSHCOM,
+		       "Export &ssh.com key");
+
+	    AppendMenu(menu, MF_POPUP | MF_ENABLED, (UINT) menu1,
+		       "&Export");
+#endif
+
+	    menu1 = CreateMenu();
+	    AppendMenu(menu1, MF_ENABLED, IDC_ABOUT, "&About");
+	    if (help_path)
+		AppendMenu(menu1, MF_ENABLED, IDC_GIVEHELP, "&Help");
+
+	    AppendMenu(menu, MF_POPUP | MF_ENABLED, (UINT) menu1, "&Help");
+
+	    SetMenu(hwnd, menu);
+	}
+
 	/*
 	 * Centre the window.
 	 */
@@ -558,8 +598,6 @@ static int CALLBACK MainDlgProc(HWND hwnd, UINT msg,
 	    /* Accelerators used: acglops1rbd */
 
 	    ctlposinit(&cp, hwnd, 4, 4, 4);
-	    bartitle(&cp, "Public and private key generation for PuTTY",
-		     IDC_TITLE);
 	    beginbox(&cp, "Key", IDC_BOX_KEY);
 	    cp2 = cp;
 	    statictext(&cp2, "No key.", 1, IDC_NOKEY);
@@ -689,6 +727,16 @@ static int CALLBACK MainDlgProc(HWND hwnd, UINT msg,
 	    EnableWindow(hwnd, 1);
 	    SetActiveWindow(hwnd);
 	    return 0;
+	  case IDC_GIVEHELP:
+            if (HIWORD(wParam) == BN_CLICKED ||
+                HIWORD(wParam) == BN_DOUBLECLICKED) {
+                if (help_path) {
+                    WinHelp(hwnd, help_path, HELP_COMMAND,
+                            (DWORD)"JI(`',`puttygen.general')");
+                    requested_help = TRUE;
+                }
+            }
+	    return 0;
 	  case IDC_GENERATE:
 	    state =
 		(struct MainDlgState *) GetWindowLong(hwnd, GWL_USERDATA);
@@ -846,15 +894,17 @@ static int CALLBACK MainDlgProc(HWND hwnd, UINT msg,
 		if (prompt_keyfile(hwnd, "Load private key:", filename, 0)) {
 		    char passphrase[PASSPHRASE_MAXLEN];
 		    int needs_pass;
-		    int type;
+		    int type, realtype;
 		    int ret;
 		    char *comment;
 		    struct PassphraseProcStruct pps;
 		    struct RSAKey newkey1;
 		    struct ssh2_userkey *newkey2 = NULL;
 
-		    type = key_type(filename);
+		    type = realtype = key_type(filename);
-		    if (type != SSH_KEYTYPE_SSH1 && type != SSH_KEYTYPE_SSH2) {
+		    if (type != SSH_KEYTYPE_SSH1 &&
+			type != SSH_KEYTYPE_SSH2 &&
+			!import_possible(type)) {
 			char msg[256];
 			sprintf(msg, "Couldn't load private key (%s)",
 				key_type_to_str(type));
@@ -863,12 +913,21 @@ static int CALLBACK MainDlgProc(HWND hwnd, UINT msg,
 			break;
 		    }
 
+		    if (type != SSH_KEYTYPE_SSH1 &&
+			type != SSH_KEYTYPE_SSH2) {
+			realtype = type;
+			type = import_target_type(type);
+		    }
+
 		    comment = NULL;
-		    if (type == SSH_KEYTYPE_SSH1)
+		    if (realtype == SSH_KEYTYPE_SSH1)
 			needs_pass = rsakey_encrypted(filename, &comment);
-		    else
+		    else if (realtype == SSH_KEYTYPE_SSH2)
 			needs_pass =
 			    ssh2_userkey_encrypted(filename, &comment);
+		    else
+			needs_pass = import_encrypted(filename, realtype,
+						      &comment);
 		    pps.passphrase = passphrase;
 		    pps.comment = comment;
 		    do {
@@ -884,12 +943,20 @@ static int CALLBACK MainDlgProc(HWND hwnd, UINT msg,
 			    }
 			} else
 			    *passphrase = '\0';
-			if (type == SSH_KEYTYPE_SSH1)
+			if (type == SSH_KEYTYPE_SSH1) {
-			    ret =
+			    if (realtype == type)
-				loadrsakey(filename, &newkey1, passphrase);
+				ret = loadrsakey(filename, &newkey1,
-			else {
+						 passphrase);
-			    newkey2 =
+			    else
-				ssh2_load_userkey(filename, passphrase);
+				ret = import_ssh1(filename, realtype,
+						  &newkey1, passphrase);
+			} else {
+			    if (realtype == type)
+				newkey2 = ssh2_load_userkey(filename,
+							    passphrase);
+			    else
+				newkey2 = import_ssh2(filename, realtype,
+						      passphrase);
 			    if (newkey2 == SSH2_WRONG_PASSPHRASE)
 				ret = -1;
 			    else if (!newkey2)

ssh.h

@@ -306,8 +306,18 @@ enum {
 int key_type(char *filename);
 char *key_type_to_str(int type);
 
+int import_possible(int type);
+int import_target_type(int type);
+int import_encrypted(char *filename, int type, char **comment);
+int import_ssh1(char *filename, int type, struct RSAKey *key,char *passphrase);
+struct ssh2_userkey *import_ssh2(char *filename, int type, char *passphrase);
+
 void des3_decrypt_pubkey(unsigned char *key, unsigned char *blk, int len);
 void des3_encrypt_pubkey(unsigned char *key, unsigned char *blk, int len);
+void des3_decrypt_pubkey_ossh(unsigned char *key, unsigned char *iv,
+			      unsigned char *blk, int len);
+void des3_encrypt_pubkey_ossh(unsigned char *key, unsigned char *iv,
+			      unsigned char *blk, int len);
 void aes256_encrypt_pubkey(unsigned char *key, unsigned char *blk,
 			   int len);
 void aes256_decrypt_pubkey(unsigned char *key, unsigned char *blk,

sshdes.c

@@ -854,6 +854,36 @@ void des3_encrypt_pubkey(unsigned char *key, unsigned char *blk, int len)
     des_3cbc_encrypt(blk, blk, len, ourkeys);
 }
 
+void des3_decrypt_pubkey_ossh(unsigned char *key, unsigned char *iv,
+			      unsigned char *blk, int len)
+{
+    DESContext ourkeys[3];
+    des_key_setup(GET_32BIT_MSB_FIRST(key),
+		  GET_32BIT_MSB_FIRST(key + 4), &ourkeys[0]);
+    des_key_setup(GET_32BIT_MSB_FIRST(key + 8),
+		  GET_32BIT_MSB_FIRST(key + 12), &ourkeys[1]);
+    des_key_setup(GET_32BIT_MSB_FIRST(key + 16),
+		  GET_32BIT_MSB_FIRST(key + 20), &ourkeys[2]);
+    ourkeys[0].div0 = GET_32BIT_MSB_FIRST(iv);
+    ourkeys[0].div1 = GET_32BIT_MSB_FIRST(iv+4);
+    des_cbc3_decrypt(blk, blk, len, ourkeys);
+}
+
+void des3_encrypt_pubkey_ossh(unsigned char *key, unsigned char *iv,
+			      unsigned char *blk, int len)
+{
+    DESContext ourkeys[3];
+    des_key_setup(GET_32BIT_MSB_FIRST(key),
+		  GET_32BIT_MSB_FIRST(key + 4), &ourkeys[0]);
+    des_key_setup(GET_32BIT_MSB_FIRST(key + 8),
+		  GET_32BIT_MSB_FIRST(key + 12), &ourkeys[1]);
+    des_key_setup(GET_32BIT_MSB_FIRST(key + 16),
+		  GET_32BIT_MSB_FIRST(key + 20), &ourkeys[2]);
+    ourkeys[0].eiv0 = GET_32BIT_MSB_FIRST(iv);
+    ourkeys[0].eiv1 = GET_32BIT_MSB_FIRST(iv+4);
+    des_cbc3_encrypt(blk, blk, len, ourkeys);
+}
+
 static const struct ssh2_cipher ssh_3des_ssh2 = {
     des3_csiv, des3_cskey,
     des3_sciv, des3_sckey,