- (djm) Merge OpenBSD changes:

   - markus@cvs.openbsd.org  2000/11/06 16:04:56
     [channels.c channels.h clientloop.c nchan.c serverloop.c]
     [session.c ssh.c]
     agent forwarding and -R for ssh2, based on work from
     jhuuskon@messi.uku.fi
   - markus@cvs.openbsd.org  2000/11/06 16:13:27
     [ssh.c sshconnect.c sshd.c]
     do not disabled rhosts(rsa) if server port > 1024; from
     pekkas@netcore.fi
   - markus@cvs.openbsd.org  2000/11/06 16:16:35
     [sshconnect.c]
     downgrade client to 1.3 if server is 1.4; help from mdb@juniper.net
   - markus@cvs.openbsd.org  2000/11/09 18:04:40
     [auth1.c]
     typo; from mouring@pconline.com
   - markus@cvs.openbsd.org  2000/11/12 12:03:28
     [ssh-agent.c]
     off-by-one when removing a key from the agent
   - markus@cvs.openbsd.org  2000/11/12 12:50:39
     [auth-rh-rsa.c auth2.c authfd.c authfd.h]
     [authfile.c hostfile.c kex.c kex.h key.c key.h myproposal.h]
     [readconf.c readconf.h rsa.c rsa.h servconf.c servconf.h ssh-add.c]
     [ssh-agent.c ssh-keygen.1 ssh-keygen.c ssh.1 ssh.c ssh_config]
     [sshconnect1.c sshconnect2.c sshd.8 sshd.c sshd_config ssh-dss.c]
     [ssh-dss.h ssh-rsa.c ssh-rsa.h dsa.c dsa.h]
     add support for RSA to SSH2.  please test.
     there are now 3 types of keys: RSA1 is used by ssh-1 only,
     RSA and DSA are used by SSH2.
     you can use 'ssh-keygen -t rsa -f ssh2_rsa_file' to generate RSA
     keys for SSH2 and use the RSA keys for hostkeys or for user keys.
     SSH2 RSA or DSA keys are added to .ssh/authorised_keys2 as before.
 - (djm) Fix up Makefile and Redhat init script to create RSA host keys
 - (djm) Change to interim version

1 files changed, 216 insertions, 0 deletions

diff --git a/ssh-dss.c b/ssh-dss.c
new file mode 100644
index 00000000..fea1fe2d
--- /dev/null
+++ b/ssh-dss.c
@@ -0,0 +1,216 @@
+/*
+ * Copyright (c) 2000 Markus Friedl.  All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "includes.h"
+RCSID("$OpenBSD: ssh-dss.c,v 1.1 2000/11/12 19:50:38 markus Exp $");
+
+#include "ssh.h"
+#include "xmalloc.h"
+#include "buffer.h"
+#include "bufaux.h"
+#include "compat.h"
+
+#include <openssl/bn.h>
+#include <openssl/rsa.h>
+#include <openssl/dsa.h>
+#include <openssl/evp.h>
+
+#include "key.h"
+
+#define INTBLOB_LEN	20
+#define SIGBLOB_LEN	(2*INTBLOB_LEN)
+
+int
+ssh_dss_sign(
+    Key *key,
+    unsigned char **sigp, int *lenp,
+    unsigned char *data, int datalen)
+{
+	unsigned char *digest;
+	unsigned char *ret;
+	DSA_SIG *sig;
+	EVP_MD *evp_md = EVP_sha1();
+	EVP_MD_CTX md;
+	unsigned int rlen;
+	unsigned int slen;
+	unsigned int len;
+	unsigned char sigblob[SIGBLOB_LEN];
+	Buffer b;
+
+	if (key == NULL || key->type != KEY_DSA || key->dsa == NULL) {
+		error("ssh_dss_sign: no DSA key");
+		return -1;
+	}
+	digest = xmalloc(evp_md->md_size);
+	EVP_DigestInit(&md, evp_md);
+	EVP_DigestUpdate(&md, data, datalen);
+	EVP_DigestFinal(&md, digest, NULL);
+
+	sig = DSA_do_sign(digest, evp_md->md_size, key->dsa);
+	if (sig == NULL) {
+		fatal("ssh_dss_sign: cannot sign");
+	}
+
+	rlen = BN_num_bytes(sig->r);
+	slen = BN_num_bytes(sig->s);
+	if (rlen > INTBLOB_LEN || slen > INTBLOB_LEN) {
+		error("bad sig size %d %d", rlen, slen);
+		DSA_SIG_free(sig);
+		return -1;
+	}
+	debug("sig size %d %d", rlen, slen);
+
+	memset(sigblob, 0, SIGBLOB_LEN);
+	BN_bn2bin(sig->r, sigblob+ SIGBLOB_LEN - INTBLOB_LEN - rlen);
+	BN_bn2bin(sig->s, sigblob+ SIGBLOB_LEN - slen);
+	DSA_SIG_free(sig);
+
+	if (datafellows & SSH_BUG_SIGBLOB) {
+		debug("datafellows");
+		ret = xmalloc(SIGBLOB_LEN);
+		memcpy(ret, sigblob, SIGBLOB_LEN);
+		if (lenp != NULL)
+			*lenp = SIGBLOB_LEN;
+		if (sigp != NULL)
+			*sigp = ret;
+	} else {
+		/* ietf-drafts */
+		buffer_init(&b);
+		buffer_put_cstring(&b, "ssh-dss");
+		buffer_put_string(&b, sigblob, SIGBLOB_LEN);
+		len = buffer_len(&b);
+		ret = xmalloc(len);
+		memcpy(ret, buffer_ptr(&b), len);
+		buffer_free(&b);
+		if (lenp != NULL)
+			*lenp = len;
+		if (sigp != NULL)
+			*sigp = ret;
+	}
+	return 0;
+}
+int
+ssh_dss_verify(
+    Key *key,
+    unsigned char *signature, int signaturelen,
+    unsigned char *data, int datalen)
+{
+	Buffer b;
+	unsigned char *digest;
+	DSA_SIG *sig;
+	EVP_MD *evp_md = EVP_sha1();
+	EVP_MD_CTX md;
+	unsigned char *sigblob;
+	char *txt;
+	unsigned int len, dlen;
+	int rlen;
+	int ret;
+
+	if (key == NULL || key->type != KEY_DSA || key->dsa == NULL) {
+		error("ssh_dss_verify: no DSA key");
+		return -1;
+	}
+
+	if (!(datafellows & SSH_BUG_SIGBLOB) &&
+	    signaturelen == SIGBLOB_LEN) {
+		datafellows |= ~SSH_BUG_SIGBLOB;
+		log("autodetect SSH_BUG_SIGBLOB");
+	} else if ((datafellows & SSH_BUG_SIGBLOB) &&
+	    signaturelen != SIGBLOB_LEN) {
+		log("autoremove SSH_BUG_SIGBLOB");
+		datafellows &= ~SSH_BUG_SIGBLOB;
+	}
+
+	debug("len %d datafellows %d", signaturelen, datafellows);
+
+	/* fetch signature */
+	if (datafellows & SSH_BUG_SIGBLOB) {
+		sigblob = signature;
+		len = signaturelen;
+	} else {
+		/* ietf-drafts */
+		char *ktype;
+		buffer_init(&b);
+		buffer_append(&b, (char *) signature, signaturelen);
+		ktype = buffer_get_string(&b, NULL);
+		if (strcmp("ssh-dss", ktype) != 0) {
+			error("ssh_dss_verify: cannot handle type %s", ktype);
+			buffer_free(&b);
+			return -1;
+		}
+		sigblob = (unsigned char *)buffer_get_string(&b, &len);
+		rlen = buffer_len(&b);
+		if(rlen != 0) {
+			error("remaining bytes in signature %d", rlen);
+			buffer_free(&b);
+			return -1;
+		}
+		buffer_free(&b);
+		xfree(ktype);
+	}
+
+	if (len != SIGBLOB_LEN) {
+		fatal("bad sigbloblen %d != SIGBLOB_LEN", len);
+	}
+
+	/* parse signature */
+	sig = DSA_SIG_new();
+	sig->r = BN_new();
+	sig->s = BN_new();
+	BN_bin2bn(sigblob, INTBLOB_LEN, sig->r);
+	BN_bin2bn(sigblob+ INTBLOB_LEN, INTBLOB_LEN, sig->s);
+
+	if (!(datafellows & SSH_BUG_SIGBLOB)) {
+		memset(sigblob, 0, len);
+		xfree(sigblob);
+	}
+	
+	/* sha1 the data */
+	dlen = evp_md->md_size;
+	digest = xmalloc(dlen);
+	EVP_DigestInit(&md, evp_md);
+	EVP_DigestUpdate(&md, data, datalen);
+	EVP_DigestFinal(&md, digest, NULL);
+
+	ret = DSA_do_verify(digest, dlen, sig, key->dsa);
+
+	memset(digest, 0, dlen);
+	xfree(digest);
+	DSA_SIG_free(sig);
+
+	switch (ret) {
+	case 1:
+		txt = "correct";
+		break;
+	case 0:
+		txt = "incorrect";
+		break;
+	case -1:
+	default:
+		txt = "error";
+		break;
+	}
+	debug("ssh_dss_verify: signature %s", txt);
+	return ret;
+}