1 files changed, 345 insertions, 0 deletions
diff --git a/src/usr.bin/gzsig/ssh.c b/src/usr.bin/gzsig/ssh.c
new file mode 100644
index 0000000..e791141
--- /dev/null
+++ b/src/usr.bin/gzsig/ssh.c
@@ -0,0 +1,345 @@
+/* $OpenBSD: ssh.c,v 1.3 2014/04/16 05:16:39 miod Exp $ */
+
+/*
+ * ssh.c
+ *
+ * Copyright (c) 2001 Dug Song <dugsong@monkey.org>
+ * Copyright (c) 2000 Niels Provos <provos@monkey.org>
+ * Copyright (c) 2000 Markus Friedl <markus@monkey.org>
+ *
+ *   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.
+ *   3. The names of the copyright holders may not be used to endorse or
+ *      promote products derived from this software without specific
+ *      prior written permission.
+ * 
+ *   THIS SOFTWARE IS PROVIDED ``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.
+ *
+ * $Vendor: ssh.c,v 1.2 2005/04/01 16:47:31 dugsong Exp $
+ */
+
+#include <sys/types.h>
+#include <sys/uio.h>
+
+#include <arpa/nameser.h>
+#include <openssl/ssl.h>
+#include <openssl/des.h>
+#include <openssl/md5.h>
+
+#include <errno.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+#include "key.h"
+#include "ssh.h"
+
+#define SSH1_MAGIC		"SSH PRIVATE KEY FILE FORMAT 1.1\n"
+
+extern int sign_passwd_cb(char *, int, int, void *);
+
+struct des3_state {
+	DES_key_schedule	k1, k2, k3;
+	DES_cblock		iv1, iv2, iv3;
+};
+
+static int
+get_bn(BIGNUM *bn, u_char **pp, int *lenp)
+{
+	short i;
+
+	if (*lenp < 2) {
+		errno = EINVAL;
+		return (-1);
+	}
+	GETSHORT(i, *pp); *lenp -= 2;
+
+	i = ((i + 7) / 8);
+
+	if (*lenp < i) {
+		errno = EINVAL;
+		return (-1);
+	}
+	BN_bin2bn(*pp, i, bn);
+	
+	*pp += i; *lenp -= i;
+
+	return (0);
+}
+
+static int
+get_string(char *dst, int len, u_char **pp, int *lenp)
+{
+	long i;
+	
+	if (*lenp < 4) {
+		errno = EINVAL;
+		return (-1);
+	}
+	GETLONG(i, *pp); *lenp -= 4;
+
+	if (*lenp < i || len < i) {
+		errno = EINVAL;
+		return (-1);
+	}
+	memcpy(dst, *pp, i);
+
+	*pp += i; *lenp -= i;
+
+	return (0);
+}
+
+static int
+read_ssh1_bn(BIGNUM *value, char **cpp)
+{
+	char *cp = *cpp;
+	int old;
+	
+	/* Skip any leading whitespace. */
+	for (; *cp == ' ' || *cp == '\t'; cp++)
+		;
+	
+	/* Check that it begins with a decimal digit. */
+	if (*cp < '0' || *cp > '9') {
+		errno = EINVAL;
+		return (-1);
+	}
+	/* Save starting position. */
+	*cpp = cp;
+	
+	/* Move forward until all decimal digits skipped. */
+	for (; *cp >= '0' && *cp <= '9'; cp++)
+		;
+	
+	/* Save the old terminating character, and replace it by \0. */
+	old = *cp;
+	*cp = 0;
+	
+	/* Parse the number. */
+	if (BN_dec2bn(&value, *cpp) == 0)
+		return (-1);
+	
+	/* Restore old terminating character. */
+	*cp = old;
+	
+	/* Move beyond the number and return success. */
+	*cpp = cp;
+	return (0);
+}
+
+/* XXX - SSH1's weirdo 3DES... */
+static void *
+des3_init(u_char *sesskey, int len)
+{
+	struct des3_state *state;
+	
+	if ((state = malloc(sizeof(*state))) == NULL)
+		return (NULL);
+
+	DES_set_key((const_DES_cblock *)sesskey, &state->k1);
+	DES_set_key((const_DES_cblock *)(sesskey + 8), &state->k2);
+
+	if (len <= 16)
+		DES_set_key((const_DES_cblock *)sesskey, &state->k3);
+	else
+		DES_set_key((const_DES_cblock *)(sesskey + 16), &state->k3);
+	
+	memset(state->iv1, 0, 8);
+	memset(state->iv2, 0, 8);
+	memset(state->iv3, 0, 8);
+	
+	return (state);
+}
+
+static void
+des3_decrypt(u_char *src, u_char *dst, int len, void *state)
+{
+	struct des3_state *dstate;
+	
+	dstate = (struct des3_state *)state;
+	memcpy(dstate->iv1, dstate->iv2, 8);
+	
+	DES_ncbc_encrypt(src, dst, len, &dstate->k3, &dstate->iv3, DES_DECRYPT);
+	DES_ncbc_encrypt(dst, dst, len, &dstate->k2, &dstate->iv2, DES_ENCRYPT);
+	DES_ncbc_encrypt(dst, dst, len, &dstate->k1, &dstate->iv1, DES_DECRYPT);
+}
+
+static int
+load_ssh1_public(RSA *rsa, struct iovec *iov)
+{
+	char *p;
+	u_int bits;
+
+	/* Skip leading whitespace. */
+	for (p = iov->iov_base; *p == ' ' || *p == '\t'; p++)
+		;
+
+	/* Get number of bits. */
+	if (*p < '0' || *p > '9')
+		return (-1);
+	
+	for (bits = 0; *p >= '0' && *p <= '9'; p++)
+		bits = 10 * bits + *p - '0';
+
+	if (bits == 0)
+		return (-1);
+	
+	/* Get public exponent, public modulus. */
+	if (read_ssh1_bn(rsa->e, &p) < 0)
+		return (-1);
+		
+	if (read_ssh1_bn(rsa->n, &p) < 0)
+		return (-1);
+
+	return (0);
+}
+
+static int
+load_ssh1_private(RSA *rsa, struct iovec *iov)
+{
+	BN_CTX *ctx;
+	BIGNUM *aux;
+	MD5_CTX md;
+	char pass[128], comment[BUFSIZ];
+	u_char *p, cipher_type, digest[16];
+	void *dstate;
+	int i;
+
+	i = strlen(SSH1_MAGIC) + 1;
+
+	/* Make sure it begins with the id string. */
+	if (iov->iov_len < i || memcmp(iov->iov_base, SSH1_MAGIC, i) != 0)
+		return (-1);
+	
+	p = (u_char *)iov->iov_base + i;
+	i = iov->iov_len - i;
+	
+	/* Skip cipher_type, reserved data, bits. */
+	cipher_type = *p;
+	p += 1 + 4 + 4;
+	i -= 1 + 4 + 4;
+
+	/* Read public key. */
+	if (get_bn(rsa->n, &p, &i) < 0 || get_bn(rsa->e, &p, &i) < 0)
+		return (-1);
+	
+	/* Read comment. */
+	if (get_string(comment, sizeof(comment), &p, &i) < 0)
+		return (-1);
+	
+	/* Decrypt private key. */
+	if (cipher_type != 0) {
+		sign_passwd_cb(pass, sizeof(pass), 0, NULL);
+
+		MD5_Init(&md);
+		MD5_Update(&md, (const u_char *)pass, strlen(pass));
+		MD5_Final(digest, &md);
+		
+		memset(pass, 0, strlen(pass));
+		
+		if ((dstate = des3_init(digest, sizeof(digest))) == NULL)
+			return (-1);
+		
+		des3_decrypt(p, p, i, dstate);
+
+		if (p[0] != p[2] || p[1] != p[3]) {
+			fprintf(stderr, "Bad passphrase for %s\n", comment);
+			return (-1);
+		}
+	}
+	else if (p[0] != p[2] || p[1] != p[3])
+		return (-1);
+	
+	p += 4;
+	i -= 4;
+	
+	/* Read the private key. */
+	if (get_bn(rsa->d, &p, &i) < 0 ||
+	    get_bn(rsa->iqmp, &p, &i) < 0)
+		return (-1);
+	
+	/* In SSL and SSH v1 p and q are exchanged. */
+	if (get_bn(rsa->q, &p, &i) < 0 ||
+	    get_bn(rsa->p, &p, &i) < 0)
+		return (-1);
+	
+	/* Calculate p-1 and q-1. */
+	ctx = BN_CTX_new();
+	aux = BN_new();
+
+	BN_sub(aux, rsa->q, BN_value_one());
+	BN_mod(rsa->dmq1, rsa->d, aux, ctx);
+
+	BN_sub(aux, rsa->p, BN_value_one());
+	BN_mod(rsa->dmp1, rsa->d, aux, ctx);
+
+	BN_clear_free(aux);
+	BN_CTX_free(ctx);
+	
+	return (0);
+}
+
+int
+ssh_load_public(struct key *k, struct iovec *iov)
+{
+	RSA *rsa;
+	
+	rsa = RSA_new();
+
+	rsa->n = BN_new();
+	rsa->e = BN_new();
+
+	if (load_ssh1_public(rsa, iov) < 0) {
+		RSA_free(rsa);
+		return (-1);
+	}
+	k->type = KEY_RSA;
+	k->data = (void *)rsa;
+	
+	return (0);
+}
+
+int
+ssh_load_private(struct key *k, struct iovec *iov)
+{
+	RSA *rsa;
+	
+	rsa = RSA_new();
+
+	rsa->n = BN_new();
+	rsa->e = BN_new();
+	
+	rsa->d = BN_new();
+	rsa->iqmp = BN_new();
+	rsa->q = BN_new();
+	rsa->p = BN_new();
+	rsa->dmq1 = BN_new();
+	rsa->dmp1 = BN_new();
+	
+	if (load_ssh1_private(rsa, iov) < 0) {
+		RSA_free(rsa);
+		return (-1);
+
+	}
+	k->type = KEY_RSA;
+	k->data = (void *)rsa;
+	
+	return (0);
+}