From d6872925c8b6b13b59a1ece32416aa8ef9c12c70 Mon Sep 17 00:00:00 2001 From: Christian Neukirchen Date: Wed, 30 Jul 2014 18:25:14 +0200 Subject: initial import of OpenBSD tools --- src/usr.bin/gzsig/ssh.c | 345 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 345 insertions(+) create mode 100644 src/usr.bin/gzsig/ssh.c (limited to 'src/usr.bin/gzsig/ssh.c') 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 + * Copyright (c) 2000 Niels Provos + * Copyright (c) 2000 Markus Friedl + * + * 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 +#include + +#include +#include +#include +#include + +#include +#include +#include +#include +#include + +#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); +} -- cgit 1.4.1