Ejemplo n.º 1
0
void
cipher_get_keyiv(CipherContext *cc, u_char *iv, u_int len)
{
	const Cipher *c = cc->cipher;
	int evplen;

	switch (c->number) {
	case SSH_CIPHER_NONE:
	case SSH_CIPHER_SSH2:
	case SSH_CIPHER_DES:
	case SSH_CIPHER_BLOWFISH:
		evplen = EVP_CIPHER_CTX_iv_length(&cc->evp);
		if (evplen <= 0)
			return;
		if ((u_int)evplen != len)
			fatal("%s: wrong iv length %d != %d", __func__,
			    evplen, len);
		if (cipher_authlen(c)) {
			if (!EVP_CIPHER_CTX_ctrl(&cc->evp, EVP_CTRL_GCM_IV_GEN,
			   len, iv))
			       fatal("%s: EVP_CTRL_GCM_IV_GEN", __func__);
		} else
			memcpy(iv, cc->evp.iv, len);
		break;
	case SSH_CIPHER_3DES:
		ssh1_3des_iv(&cc->evp, 0, iv, 24);
		break;
	default:
		fatal("%s: bad cipher %d", __func__, c->number);
	}
}
Ejemplo n.º 2
0
int
cipher_set_keyiv(struct sshcipher_ctx *cc, const u_char *iv)
{
#ifdef WITH_OPENSSL
	const struct sshcipher *c = cc->cipher;
	int evplen = 0;
#endif

	if ((cc->cipher->flags & CFLAG_CHACHAPOLY) != 0)
		return 0;
	if ((cc->cipher->flags & CFLAG_NONE) != 0)
		return 0;

#ifdef WITH_OPENSSL
	evplen = EVP_CIPHER_CTX_iv_length(cc->evp);
	if (evplen <= 0)
		return SSH_ERR_LIBCRYPTO_ERROR;
	if (cipher_authlen(c)) {
		/* XXX iv arg is const, but EVP_CIPHER_CTX_ctrl isn't */
		if (!EVP_CIPHER_CTX_ctrl(cc->evp,
		    EVP_CTRL_GCM_SET_IV_FIXED, -1, __UNCONST(iv)))
		     return SSH_ERR_LIBCRYPTO_ERROR;
	} else
		memcpy(EVP_CIPHER_CTX_iv_noconst(cc->evp), iv, evplen);
#endif
	return 0;
}
Ejemplo n.º 3
0
void
cipher_set_keyiv(CipherContext *cc, u_char *iv)
{
	const Cipher *c = cc->cipher;
	int evplen = 0;

	switch (c->number) {
	case SSH_CIPHER_NONE:
	case SSH_CIPHER_SSH2:
	case SSH_CIPHER_DES:
	case SSH_CIPHER_BLOWFISH:
		evplen = EVP_CIPHER_CTX_iv_length(&cc->evp);
		if (evplen == 0)
			return;
		if (cipher_authlen(c)) {
			if (!EVP_CIPHER_CTX_ctrl(&cc->evp,
			    EVP_CTRL_GCM_SET_IV_FIXED, -1, iv))
				fatal("%s: EVP_CTRL_GCM_SET_IV_FIXED failed",
				    __func__);
		} else
			memcpy(cc->evp.iv, iv, evplen);
		break;
	case SSH_CIPHER_3DES:
		ssh1_3des_iv(&cc->evp, 1, iv, 24);
		break;
	default:
		fatal("%s: bad cipher %d", __func__, c->number);
	}
}
Ejemplo n.º 4
0
int
cipher_set_keyiv(struct sshcipher_ctx *cc, const u_char *iv, size_t len)
{
#ifdef WITH_OPENSSL
	const struct sshcipher *c = cc->cipher;
	int evplen = 0;
#endif

	if ((cc->cipher->flags & CFLAG_CHACHAPOLY) != 0)
		return 0;
	if ((cc->cipher->flags & CFLAG_NONE) != 0)
		return 0;

#ifdef WITH_OPENSSL
	evplen = EVP_CIPHER_CTX_iv_length(cc->evp);
	if (evplen <= 0)
		return SSH_ERR_LIBCRYPTO_ERROR;
	if ((size_t)evplen != len)
		return SSH_ERR_INVALID_ARGUMENT;
	if (cipher_authlen(c)) {
		/* XXX iv arg is const, but EVP_CIPHER_CTX_ctrl isn't */
		if (!EVP_CIPHER_CTX_ctrl(cc->evp,
		    EVP_CTRL_GCM_SET_IV_FIXED, -1, (void *)iv))
			return SSH_ERR_LIBCRYPTO_ERROR;
	} else if (!EVP_CIPHER_CTX_set_iv(cc->evp, iv, evplen))
		return SSH_ERR_LIBCRYPTO_ERROR;
#endif
	return 0;
}
Ejemplo n.º 5
0
/* Export key state after authentication */
Newkeys *
mm_newkeys_from_blob(u_char *blob, int blen)
{
	Buffer b;
	u_int len;
	Newkeys *newkey = NULL;
	Enc *enc;
	Mac *mac;
	Comp *comp;

	debug3("%s: %p(%d)", __func__, blob, blen);
#ifdef DEBUG_PK
	dump_base64(stderr, blob, blen);
#endif
	buffer_init(&b);
	buffer_append(&b, blob, blen);

	newkey = xcalloc(1, sizeof(*newkey));
	enc = &newkey->enc;
	mac = &newkey->mac;
	comp = &newkey->comp;

	/* Enc structure */
	enc->name = buffer_get_string(&b, NULL);
	buffer_get(&b, &enc->cipher, sizeof(enc->cipher));
	enc->enabled = buffer_get_int(&b);
	enc->block_size = buffer_get_int(&b);
	enc->key = buffer_get_string(&b, &enc->key_len);
	enc->iv = buffer_get_string(&b, &enc->iv_len);

	if (enc->name == NULL || cipher_by_name(enc->name) != enc->cipher)
		fatal("%s: bad cipher name %s or pointer %p", __func__,
		    enc->name, enc->cipher);

	/* Mac structure */
	if (cipher_authlen(enc->cipher) == 0) {
		mac->name = buffer_get_string(&b, NULL);
		if (mac->name == NULL || mac_setup(mac, mac->name) == -1)
			fatal("%s: can not setup mac %s", __func__, mac->name);
		mac->enabled = buffer_get_int(&b);
		mac->key = buffer_get_string(&b, &len);
		if (len > mac->key_len)
			fatal("%s: bad mac key length: %u > %d", __func__, len,
			    mac->key_len);
		mac->key_len = len;
	}

	/* Comp structure */
	comp->type = buffer_get_int(&b);
	comp->enabled = buffer_get_int(&b);
	comp->name = buffer_get_string(&b, NULL);

	len = buffer_len(&b);
	if (len != 0)
		error("newkeys_from_blob: remaining bytes in blob %u", len);
	buffer_free(&b);
	return (newkey);
}
Ejemplo n.º 6
0
int
cipher_get_keyiv(struct sshcipher_ctx *cc, u_char *iv, u_int len)
{
	const struct sshcipher *c = cc->cipher;
#ifdef WITH_OPENSSL
 	int evplen;
#endif

	if ((cc->cipher->flags & CFLAG_CHACHAPOLY) != 0) {
		if (len != 0)
			return SSH_ERR_INVALID_ARGUMENT;
		return 0;
	}
	if ((cc->cipher->flags & CFLAG_AESCTR) != 0) {
		if (len != sizeof(cc->ac_ctx.ctr))
			return SSH_ERR_INVALID_ARGUMENT;
		memcpy(iv, cc->ac_ctx.ctr, len);
		return 0;
	}
	if ((cc->cipher->flags & CFLAG_NONE) != 0)
		return 0;

	switch (c->number) {
#ifdef WITH_OPENSSL
	case SSH_CIPHER_SSH2:
	case SSH_CIPHER_DES:
	case SSH_CIPHER_BLOWFISH:
		evplen = EVP_CIPHER_CTX_iv_length(&cc->evp);
		if (evplen == 0)
			return 0;
		else if (evplen < 0)
			return SSH_ERR_LIBCRYPTO_ERROR;
		if ((u_int)evplen != len)
			return SSH_ERR_INVALID_ARGUMENT;
#ifndef OPENSSL_HAVE_EVPCTR
		if (c->evptype == evp_aes_128_ctr)
			ssh_aes_ctr_iv(&cc->evp, 0, iv, len);
		else
#endif
		if (cipher_authlen(c)) {
			if (!EVP_CIPHER_CTX_ctrl(&cc->evp, EVP_CTRL_GCM_IV_GEN,
			   len, iv))
			       return SSH_ERR_LIBCRYPTO_ERROR;
		} else
			memcpy(iv, cc->evp.iv, len);
		break;
#endif
#ifdef WITH_SSH1
	case SSH_CIPHER_3DES:
		return ssh1_3des_iv(&cc->evp, 0, iv, 24);
#endif
	default:
		return SSH_ERR_INVALID_ARGUMENT;
	}
	return 0;
}
Ejemplo n.º 7
0
int
mm_newkeys_to_blob(int mode, u_char **blobp, u_int *lenp)
{
	Buffer b;
	int len;
	Enc *enc;
	Mac *mac;
	Comp *comp;
	Newkeys *newkey = (Newkeys *)packet_get_newkeys(mode);

	debug3("%s: converting %p", __func__, newkey);

	if (newkey == NULL) {
		error("%s: newkey == NULL", __func__);
		return 0;
	}
	enc = &newkey->enc;
	mac = &newkey->mac;
	comp = &newkey->comp;

	buffer_init(&b);
	/* Enc structure */
	buffer_put_cstring(&b, enc->name);
	/* The cipher struct is constant and shared, you export pointer */
	buffer_append(&b, &enc->cipher, sizeof(enc->cipher));
	buffer_put_int(&b, enc->enabled);
	buffer_put_int(&b, enc->block_size);
	buffer_put_string(&b, enc->key, enc->key_len);
	packet_get_keyiv(mode, enc->iv, enc->iv_len);
	buffer_put_string(&b, enc->iv, enc->iv_len);

	/* Mac structure */
	if (cipher_authlen(enc->cipher) == 0) {
		buffer_put_cstring(&b, mac->name);
		buffer_put_int(&b, mac->enabled);
		buffer_put_string(&b, mac->key, mac->key_len);
	}

	/* Comp structure */
	buffer_put_int(&b, comp->type);
	buffer_put_int(&b, comp->enabled);
	buffer_put_cstring(&b, comp->name);

	len = buffer_len(&b);
	if (lenp != NULL)
		*lenp = len;
	if (blobp != NULL) {
		*blobp = xmalloc(len);
		memcpy(*blobp, buffer_ptr(&b), len);
	}
	explicit_bzero(buffer_ptr(&b), len);
	buffer_free(&b);
	return len;
}
Ejemplo n.º 8
0
/*
 * cipher_crypt() operates as following:
 * Copy 'aadlen' bytes (without en/decryption) from 'src' to 'dest'.
 * Theses bytes are treated as additional authenticated data for
 * authenticated encryption modes.
 * En/Decrypt 'len' bytes at offset 'aadlen' from 'src' to 'dest'.
 * Use 'authlen' bytes at offset 'len'+'aadlen' as the authentication tag.
 * This tag is written on encryption and verified on decryption.
 * Both 'aadlen' and 'authlen' can be set to 0.
 * cipher_crypt() returns 0 on success and -1 if the decryption integrity
 * check fails.
 */
int
cipher_crypt(CipherContext *cc, u_int seqnr, u_char *dest, const u_char *src,
    u_int len, u_int aadlen, u_int authlen)
{
	if ((cc->cipher->flags & CFLAG_CHACHAPOLY) != 0)
		return chachapoly_crypt(&cc->cp_ctx, seqnr, dest, src, len,
		    aadlen, authlen, cc->encrypt);
	if (authlen) {
		u_char lastiv[1];

		if (authlen != cipher_authlen(cc->cipher))
			fatal("%s: authlen mismatch %d", __func__, authlen);
		/* increment IV */
		if (!EVP_CIPHER_CTX_ctrl(&cc->evp, EVP_CTRL_GCM_IV_GEN,
		    1, lastiv))
			fatal("%s: EVP_CTRL_GCM_IV_GEN", __func__);
		/* set tag on decyption */
		if (!cc->encrypt &&
		    !EVP_CIPHER_CTX_ctrl(&cc->evp, EVP_CTRL_GCM_SET_TAG,
		    authlen, (u_char *)src + aadlen + len))
			fatal("%s: EVP_CTRL_GCM_SET_TAG", __func__);
	}
	if (aadlen) {
		if (authlen &&
		    EVP_Cipher(&cc->evp, NULL, (u_char *)src, aadlen) < 0)
			fatal("%s: EVP_Cipher(aad) failed", __func__);
		memcpy(dest, src, aadlen);
	}
	if (len % cc->cipher->block_size)
		fatal("%s: bad plaintext length %d", __func__, len);
	if (EVP_Cipher(&cc->evp, dest + aadlen, (u_char *)src + aadlen,
	    len) < 0)
		fatal("%s: EVP_Cipher failed", __func__);
	if (authlen) {
		/* compute tag (on encrypt) or verify tag (on decrypt) */
		if (EVP_Cipher(&cc->evp, NULL, NULL, 0) < 0) {
			if (cc->encrypt)
				fatal("%s: EVP_Cipher(final) failed", __func__);
			else
				return -1;
		}
		if (cc->encrypt &&
		    !EVP_CIPHER_CTX_ctrl(&cc->evp, EVP_CTRL_GCM_GET_TAG,
		    authlen, dest + aadlen + len))
			fatal("%s: EVP_CTRL_GCM_GET_TAG", __func__);
	}
	return 0;
}
Ejemplo n.º 9
0
int
cipher_get_keyiv(struct sshcipher_ctx *cc, u_char *iv, size_t len)
{
#ifdef WITH_OPENSSL
	const struct sshcipher *c = cc->cipher;
	int evplen;
#endif

	if ((cc->cipher->flags & CFLAG_CHACHAPOLY) != 0) {
		if (len != 0)
			return SSH_ERR_INVALID_ARGUMENT;
		return 0;
	}
	if ((cc->cipher->flags & CFLAG_AESCTR) != 0) {
		if (len != sizeof(cc->ac_ctx.ctr))
			return SSH_ERR_INVALID_ARGUMENT;
		memcpy(iv, cc->ac_ctx.ctr, len);
		return 0;
	}
	if ((cc->cipher->flags & CFLAG_NONE) != 0)
		return 0;

#ifdef WITH_OPENSSL
	evplen = EVP_CIPHER_CTX_iv_length(cc->evp);
	if (evplen == 0)
		return 0;
	else if (evplen < 0)
		return SSH_ERR_LIBCRYPTO_ERROR;
	if ((size_t)evplen != len)
		return SSH_ERR_INVALID_ARGUMENT;
#ifndef OPENSSL_HAVE_EVPCTR
	if (c->evptype == evp_aes_128_ctr)
		ssh_aes_ctr_iv(cc->evp, 0, iv, len);
	else
#endif
	if (cipher_authlen(c)) {
		if (!EVP_CIPHER_CTX_ctrl(cc->evp, EVP_CTRL_GCM_IV_GEN,
		   len, iv))
		       return SSH_ERR_LIBCRYPTO_ERROR;
	} else if (!EVP_CIPHER_CTX_get_iv(cc->evp, iv, len))
	       return SSH_ERR_LIBCRYPTO_ERROR;
#endif
	return 0;
}
Ejemplo n.º 10
0
/*
 * cipher_crypt() operates as following:
 * Copy 'aadlen' bytes (without en/decryption) from 'src' to 'dest'.
 * Theses bytes are treated as additional authenticated data for
 * authenticated encryption modes.
 * En/Decrypt 'len' bytes at offset 'aadlen' from 'src' to 'dest'.
 * Use 'authlen' bytes at offset 'len'+'aadlen' as the authentication tag.
 * This tag is written on encryption and verified on decryption.
 * Both 'aadlen' and 'authlen' can be set to 0.
 */
void
cipher_crypt(CipherContext *cc, u_char *dest, const u_char *src,
    u_int len, u_int aadlen, u_int authlen)
{
	if (authlen) {
		u_char lastiv[1];

		if (authlen != cipher_authlen(cc->cipher))
			fatal("%s: authlen mismatch %d", __func__, authlen);
		/* increment IV */
		if (!EVP_CIPHER_CTX_ctrl(&cc->evp, EVP_CTRL_GCM_IV_GEN,
		    1, lastiv))
			fatal("%s: EVP_CTRL_GCM_IV_GEN", __func__);
		/* set tag on decyption */
		if (!cc->encrypt &&
		    !EVP_CIPHER_CTX_ctrl(&cc->evp, EVP_CTRL_GCM_SET_TAG,
		    authlen, __UNCONST(src + aadlen + len)))
			fatal("%s: EVP_CTRL_GCM_SET_TAG", __func__);
	}
	if (aadlen) {
		if (authlen &&
		    EVP_Cipher(&cc->evp, NULL, (const u_char *)src, aadlen) < 0)
			fatal("%s: EVP_Cipher(aad) failed", __func__);
		memcpy(dest, src, aadlen);
	}
	if (len % cc->cipher->block_size)
		fatal("%s: bad plaintext length %d", __func__, len);
	if (EVP_Cipher(&cc->evp, dest + aadlen, (const u_char *)src + aadlen,
	    len) < 0)
		fatal("%s: EVP_Cipher failed", __func__);
	if (authlen) {
		/* compute tag (on encrypt) or verify tag (on decrypt) */
		if (EVP_Cipher(&cc->evp, NULL, NULL, 0) < 0) {
			if (cc->encrypt)
				fatal("%s: EVP_Cipher(final) failed", __func__);
			else
				fatal("Decryption integrity check failed");
		}
		if (cc->encrypt &&
		    !EVP_CIPHER_CTX_ctrl(&cc->evp, EVP_CTRL_GCM_GET_TAG,
		    authlen, dest + aadlen + len))
			fatal("%s: EVP_CTRL_GCM_GET_TAG", __func__);
	}
}
Ejemplo n.º 11
0
int
cipher_set_keyiv(struct sshcipher_ctx *cc, const u_char *iv)
{
	const struct sshcipher *c = cc->cipher;
#ifdef WITH_OPENSSL
 	int evplen = 0;
#endif

	if ((cc->cipher->flags & CFLAG_CHACHAPOLY) != 0)
		return 0;
	if ((cc->cipher->flags & CFLAG_NONE) != 0)
		return 0;

	switch (c->number) {
#ifdef WITH_OPENSSL
	case SSH_CIPHER_NONE:
	case SSH_CIPHER_SSH2:
	case SSH_CIPHER_DES:
	case SSH_CIPHER_BLOWFISH:
		evplen = EVP_CIPHER_CTX_iv_length(cc->evp);
		if (evplen <= 0)
			return SSH_ERR_LIBCRYPTO_ERROR;
		if (cipher_authlen(c)) {
			/* XXX iv arg is const, but EVP_CIPHER_CTX_ctrl isn't */
			if (!EVP_CIPHER_CTX_ctrl(cc->evp,
			    EVP_CTRL_GCM_SET_IV_FIXED, -1, __UNCONST(iv)))
				return SSH_ERR_LIBCRYPTO_ERROR;
		} else
			memcpy(cc->evp->iv, iv, evplen);
		break;
#endif
#ifdef WITH_SSH1
	case SSH_CIPHER_3DES:
		return ssh1_3des_iv(cc->evp, 1, __UNCONST(iv), 24);
#endif
	default:
		return SSH_ERR_INVALID_ARGUMENT;
	}
	return 0;
}
Ejemplo n.º 12
0
Archivo: kex.c Proyecto: OpenKod/src
static void
kex_choose_conf(Kex *kex)
{
	Newkeys *newkeys;
	char **my, **peer;
	char **cprop, **sprop;
	int nenc, nmac, ncomp;
	u_int mode, ctos, need, dh_need, authlen;
	int first_kex_follows, type;
#ifdef	NONE_CIPHER_ENABLED
	int auth_flag;
#endif

	my   = kex_buf2prop(&kex->my, NULL);
	peer = kex_buf2prop(&kex->peer, &first_kex_follows);

	if (kex->server) {
		cprop=peer;
		sprop=my;
	} else {
		cprop=my;
		sprop=peer;
	}

	/* Check whether server offers roaming */
	if (!kex->server) {
		char *roaming;
		roaming = match_list(KEX_RESUME, peer[PROPOSAL_KEX_ALGS], NULL);
		if (roaming) {
			kex->roaming = 1;
			free(roaming);
		}
	}

	/* Algorithm Negotiation */
#ifdef	NONE_CIPHER_ENABLED
	auth_flag = packet_get_authentication_state();
	debug ("AUTH STATE is %d", auth_flag);
#endif
	for (mode = 0; mode < MODE_MAX; mode++) {
		newkeys = xcalloc(1, sizeof(*newkeys));
		kex->newkeys[mode] = newkeys;
		ctos = (!kex->server && mode == MODE_OUT) ||
		    (kex->server && mode == MODE_IN);
		nenc  = ctos ? PROPOSAL_ENC_ALGS_CTOS  : PROPOSAL_ENC_ALGS_STOC;
		nmac  = ctos ? PROPOSAL_MAC_ALGS_CTOS  : PROPOSAL_MAC_ALGS_STOC;
		ncomp = ctos ? PROPOSAL_COMP_ALGS_CTOS : PROPOSAL_COMP_ALGS_STOC;
		choose_enc(&newkeys->enc, cprop[nenc], sprop[nenc]);
		/* ignore mac for authenticated encryption */
		authlen = cipher_authlen(newkeys->enc.cipher);
		if (authlen == 0)
			choose_mac(&newkeys->mac, cprop[nmac], sprop[nmac]);
		choose_comp(&newkeys->comp, cprop[ncomp], sprop[ncomp]);
#ifdef	NONE_CIPHER_ENABLED
		debug("REQUESTED ENC.NAME is '%s'", newkeys->enc.name);
		if (strcmp(newkeys->enc.name, "none") == 0) {
			debug("Requesting NONE. Authflag is %d", auth_flag);
			if (auth_flag == 1)
				debug("None requested post authentication.");
			else
				fatal("Pre-authentication none cipher requests "
				    "are not allowed.");
		}
#endif
		debug("kex: %s %s %s %s",
		    ctos ? "client->server" : "server->client",
		    newkeys->enc.name,
		    authlen == 0 ? newkeys->mac.name : "<implicit>",
		    newkeys->comp.name);
	}
	choose_kex(kex, cprop[PROPOSAL_KEX_ALGS], sprop[PROPOSAL_KEX_ALGS]);
	choose_hostkeyalg(kex, cprop[PROPOSAL_SERVER_HOST_KEY_ALGS],
	    sprop[PROPOSAL_SERVER_HOST_KEY_ALGS]);
	need = dh_need = 0;
	for (mode = 0; mode < MODE_MAX; mode++) {
		newkeys = kex->newkeys[mode];
		need = MAX(need, newkeys->enc.key_len);
		need = MAX(need, newkeys->enc.block_size);
		need = MAX(need, newkeys->enc.iv_len);
		need = MAX(need, newkeys->mac.key_len);
		dh_need = MAX(dh_need, cipher_seclen(newkeys->enc.cipher));
		dh_need = MAX(dh_need, newkeys->enc.block_size);
		dh_need = MAX(dh_need, newkeys->enc.iv_len);
		dh_need = MAX(dh_need, newkeys->mac.key_len);
	}
	/* XXX need runden? */
	kex->we_need = need;
	kex->dh_need = dh_need;

	/* ignore the next message if the proposals do not match */
	if (first_kex_follows && !proposals_match(my, peer) &&
	    !(datafellows & SSH_BUG_FIRSTKEX)) {
		type = packet_read();
		debug2("skipping next packet (type %u)", type);
	}

	kex_prop_free(my);
	kex_prop_free(peer);
}
Ejemplo n.º 13
0
static void
kex_choose_conf(Kex *kex)
{
	Newkeys *newkeys;
	char **my, **peer;
	char **cprop, **sprop;
	int nenc, nmac, ncomp;
	u_int mode, ctos, need, authlen;
	int first_kex_follows, type;

	my   = kex_buf2prop(&kex->my, NULL);
	peer = kex_buf2prop(&kex->peer, &first_kex_follows);

	if (kex->server) {
		cprop=peer;
		sprop=my;
	} else {
		cprop=my;
		sprop=peer;
	}

	/* Check whether server offers roaming */
	if (!kex->server) {
		char *roaming;
		roaming = match_list(KEX_RESUME, peer[PROPOSAL_KEX_ALGS], NULL);
		if (roaming) {
			kex->roaming = 1;
			free(roaming);
		}
	}

	/* Algorithm Negotiation */
	for (mode = 0; mode < MODE_MAX; mode++) {
		newkeys = xcalloc(1, sizeof(*newkeys));
		kex->newkeys[mode] = newkeys;
		ctos = (!kex->server && mode == MODE_OUT) ||
		    (kex->server && mode == MODE_IN);
		nenc  = ctos ? PROPOSAL_ENC_ALGS_CTOS  : PROPOSAL_ENC_ALGS_STOC;
		nmac  = ctos ? PROPOSAL_MAC_ALGS_CTOS  : PROPOSAL_MAC_ALGS_STOC;
		ncomp = ctos ? PROPOSAL_COMP_ALGS_CTOS : PROPOSAL_COMP_ALGS_STOC;
		choose_enc(&newkeys->enc, cprop[nenc], sprop[nenc]);
		/* ignore mac for authenticated encryption */
		authlen = cipher_authlen(newkeys->enc.cipher);
		if (authlen == 0)
			choose_mac(&newkeys->mac, cprop[nmac], sprop[nmac]);
		choose_comp(&newkeys->comp, cprop[ncomp], sprop[ncomp]);
		debug("kex: %s %s %s %s",
		    ctos ? "client->server" : "server->client",
		    newkeys->enc.name,
		    authlen == 0 ? newkeys->mac.name : "<implicit>",
		    newkeys->comp.name);
	}
	choose_kex(kex, cprop[PROPOSAL_KEX_ALGS], sprop[PROPOSAL_KEX_ALGS]);
	choose_hostkeyalg(kex, cprop[PROPOSAL_SERVER_HOST_KEY_ALGS],
	    sprop[PROPOSAL_SERVER_HOST_KEY_ALGS]);
	need = 0;
	for (mode = 0; mode < MODE_MAX; mode++) {
		newkeys = kex->newkeys[mode];
		if (need < newkeys->enc.key_len)
			need = newkeys->enc.key_len;
		if (need < newkeys->enc.block_size)
			need = newkeys->enc.block_size;
		if (need < newkeys->enc.iv_len)
			need = newkeys->enc.iv_len;
		if (need < newkeys->mac.key_len)
			need = newkeys->mac.key_len;
	}
	/* XXX need runden? */
	kex->we_need = need;

	/* ignore the next message if the proposals do not match */
	if (first_kex_follows && !proposals_match(my, peer) &&
	    !(datafellows & SSH_BUG_FIRSTKEX)) {
		type = packet_read();
		debug2("skipping next packet (type %u)", type);
	}

	kex_prop_free(my);
	kex_prop_free(peer);
}
Ejemplo n.º 14
0
int
cipher_init(struct sshcipher_ctx *cc, const struct sshcipher *cipher,
    const u_char *key, u_int keylen, const u_char *iv, u_int ivlen,
    int do_encrypt)
{
#ifdef WITH_OPENSSL
	int ret = SSH_ERR_INTERNAL_ERROR;
	const EVP_CIPHER *type;
	int klen;
	u_char *junk, *discard;

	if (cipher->number == SSH_CIPHER_DES) {
		if (keylen > 8)
			keylen = 8;
	}
#endif
	cc->plaintext = (cipher->number == SSH_CIPHER_NONE);
	cc->encrypt = do_encrypt;

	if (keylen < cipher->key_len ||
	    (iv != NULL && ivlen < cipher_ivlen(cipher)))
		return SSH_ERR_INVALID_ARGUMENT;

	cc->cipher = cipher;
	if ((cc->cipher->flags & CFLAG_CHACHAPOLY) != 0) {
		return chachapoly_init(&cc->cp_ctx, key, keylen);
	}
#ifndef WITH_OPENSSL
	if ((cc->cipher->flags & CFLAG_AESCTR) != 0) {
		aesctr_keysetup(&cc->ac_ctx, key, 8 * keylen, 8 * ivlen);
		aesctr_ivsetup(&cc->ac_ctx, iv);
		return 0;
	}
	if ((cc->cipher->flags & CFLAG_NONE) != 0)
		return 0;
	return SSH_ERR_INVALID_ARGUMENT;
#else
	type = (*cipher->evptype)();
	EVP_CIPHER_CTX_init(&cc->evp);
	if (EVP_CipherInit(&cc->evp, type, NULL, (u_char *)iv,
	    (do_encrypt == CIPHER_ENCRYPT)) == 0) {
		ret = SSH_ERR_LIBCRYPTO_ERROR;
		goto bad;
	}
	if (cipher_authlen(cipher) &&
	    !EVP_CIPHER_CTX_ctrl(&cc->evp, EVP_CTRL_GCM_SET_IV_FIXED,
	    -1, (u_char *)iv)) {
		ret = SSH_ERR_LIBCRYPTO_ERROR;
		goto bad;
	}
	klen = EVP_CIPHER_CTX_key_length(&cc->evp);
	if (klen > 0 && keylen != (u_int)klen) {
		if (EVP_CIPHER_CTX_set_key_length(&cc->evp, keylen) == 0) {
			ret = SSH_ERR_LIBCRYPTO_ERROR;
			goto bad;
		}
	}
	if (EVP_CipherInit(&cc->evp, NULL, (u_char *)key, NULL, -1) == 0) {
		ret = SSH_ERR_LIBCRYPTO_ERROR;
		goto bad;
	}

	if (cipher->discard_len > 0) {
		if ((junk = malloc(cipher->discard_len)) == NULL ||
		    (discard = malloc(cipher->discard_len)) == NULL) {
			if (junk != NULL)
				free(junk);
			ret = SSH_ERR_ALLOC_FAIL;
			goto bad;
		}
		ret = EVP_Cipher(&cc->evp, discard, junk, cipher->discard_len);
		explicit_bzero(discard, cipher->discard_len);
		free(junk);
		free(discard);
		if (ret != 1) {
			ret = SSH_ERR_LIBCRYPTO_ERROR;
 bad:
			EVP_CIPHER_CTX_cleanup(&cc->evp);
			return ret;
		}
	}
#endif
	return 0;
}
Ejemplo n.º 15
0
int
sshkey_xmss_encrypt_state(const struct sshkey *k, struct sshbuf *b,
   struct sshbuf **retp)
{
	struct ssh_xmss_state *state = k->xmss_state;
	struct sshbuf *encrypted = NULL, *encoded = NULL, *padded = NULL;
	struct sshcipher_ctx *ciphercontext = NULL;
	const struct sshcipher *cipher;
	u_char *cp, *key, *iv = NULL;
	size_t i, keylen, ivlen, blocksize, authlen, encrypted_len, aadlen;
	int r = SSH_ERR_INTERNAL_ERROR;

	if (retp != NULL)
		*retp = NULL;
	if (state == NULL ||
	    state->enc_keyiv == NULL ||
	    state->enc_ciphername == NULL)
		return SSH_ERR_INTERNAL_ERROR;
	if ((cipher = cipher_by_name(state->enc_ciphername)) == NULL) {
		r = SSH_ERR_INTERNAL_ERROR;
		goto out;
	}
	blocksize = cipher_blocksize(cipher);
	keylen = cipher_keylen(cipher);
	ivlen = cipher_ivlen(cipher);
	authlen = cipher_authlen(cipher);
	if (state->enc_keyiv_len != keylen + ivlen) {
		r = SSH_ERR_INVALID_FORMAT;
		goto out;
	}
	key = state->enc_keyiv;
	if ((encrypted = sshbuf_new()) == NULL ||
	    (encoded = sshbuf_new()) == NULL ||
	    (padded = sshbuf_new()) == NULL ||
	    (iv = malloc(ivlen)) == NULL) {
		r = SSH_ERR_ALLOC_FAIL;
		goto out;
	}

	/* replace first 4 bytes of IV with index to ensure uniqueness */
	memcpy(iv, key + keylen, ivlen);
	POKE_U32(iv, state->idx);

	if ((r = sshbuf_put(encoded, XMSS_MAGIC, sizeof(XMSS_MAGIC))) != 0 ||
	    (r = sshbuf_put_u32(encoded, state->idx)) != 0)
		goto out;

	/* padded state will be encrypted */
	if ((r = sshbuf_putb(padded, b)) != 0)
		goto out;
	i = 0;
	while (sshbuf_len(padded) % blocksize) {
		if ((r = sshbuf_put_u8(padded, ++i & 0xff)) != 0)
			goto out;
	}
	encrypted_len = sshbuf_len(padded);

	/* header including the length of state is used as AAD */
	if ((r = sshbuf_put_u32(encoded, encrypted_len)) != 0)
		goto out;
	aadlen = sshbuf_len(encoded);

	/* concat header and state */
	if ((r = sshbuf_putb(encoded, padded)) != 0)
		goto out;

	/* reserve space for encryption of encoded data plus auth tag */
	/* encrypt at offset addlen */
	if ((r = sshbuf_reserve(encrypted,
	    encrypted_len + aadlen + authlen, &cp)) != 0 ||
	    (r = cipher_init(&ciphercontext, cipher, key, keylen,
	    iv, ivlen, 1)) != 0 ||
	    (r = cipher_crypt(ciphercontext, 0, cp, sshbuf_ptr(encoded),
	    encrypted_len, aadlen, authlen)) != 0)
		goto out;

	/* success */
	r = 0;
 out:
	if (retp != NULL) {
		*retp = encrypted;
		encrypted = NULL;
	}
	sshbuf_free(padded);
	sshbuf_free(encoded);
	sshbuf_free(encrypted);
	cipher_free(ciphercontext);
	free(iv);
	return r;
}
Ejemplo n.º 16
0
int
sshkey_xmss_decrypt_state(const struct sshkey *k, struct sshbuf *encoded,
   struct sshbuf **retp)
{
	struct ssh_xmss_state *state = k->xmss_state;
	struct sshbuf *copy = NULL, *decrypted = NULL;
	struct sshcipher_ctx *ciphercontext = NULL;
	const struct sshcipher *cipher = NULL;
	u_char *key, *iv = NULL, *dp;
	size_t keylen, ivlen, authlen, aadlen;
	u_int blocksize, encrypted_len, index;
	int r = SSH_ERR_INTERNAL_ERROR;

	if (retp != NULL)
		*retp = NULL;
	if (state == NULL ||
	    state->enc_keyiv == NULL ||
	    state->enc_ciphername == NULL)
		return SSH_ERR_INTERNAL_ERROR;
	if ((cipher = cipher_by_name(state->enc_ciphername)) == NULL) {
		r = SSH_ERR_INVALID_FORMAT;
		goto out;
	}
	blocksize = cipher_blocksize(cipher);
	keylen = cipher_keylen(cipher);
	ivlen = cipher_ivlen(cipher);
	authlen = cipher_authlen(cipher);
	if (state->enc_keyiv_len != keylen + ivlen) {
		r = SSH_ERR_INTERNAL_ERROR;
		goto out;
	}
	key = state->enc_keyiv;

	if ((copy = sshbuf_fromb(encoded)) == NULL ||
	    (decrypted = sshbuf_new()) == NULL ||
	    (iv = malloc(ivlen)) == NULL) {
		r = SSH_ERR_ALLOC_FAIL;
		goto out;
	}

	/* check magic */
	if (sshbuf_len(encoded) < sizeof(XMSS_MAGIC) ||
	    memcmp(sshbuf_ptr(encoded), XMSS_MAGIC, sizeof(XMSS_MAGIC))) {
		r = SSH_ERR_INVALID_FORMAT;
		goto out;
	}
	/* parse public portion */
	if ((r = sshbuf_consume(encoded, sizeof(XMSS_MAGIC))) != 0 ||
	    (r = sshbuf_get_u32(encoded, &index)) != 0 ||
	    (r = sshbuf_get_u32(encoded, &encrypted_len)) != 0)
		goto out;

	/* check size of encrypted key blob */
	if (encrypted_len < blocksize || (encrypted_len % blocksize) != 0) {
		r = SSH_ERR_INVALID_FORMAT;
		goto out;
	}
	/* check that an appropriate amount of auth data is present */
	if (sshbuf_len(encoded) < encrypted_len + authlen) {
		r = SSH_ERR_INVALID_FORMAT;
		goto out;
	}

	aadlen = sshbuf_len(copy) - sshbuf_len(encoded);

	/* replace first 4 bytes of IV with index to ensure uniqueness */
	memcpy(iv, key + keylen, ivlen);
	POKE_U32(iv, index);

	/* decrypt private state of key */
	if ((r = sshbuf_reserve(decrypted, aadlen + encrypted_len, &dp)) != 0 ||
	    (r = cipher_init(&ciphercontext, cipher, key, keylen,
	    iv, ivlen, 0)) != 0 ||
	    (r = cipher_crypt(ciphercontext, 0, dp, sshbuf_ptr(copy),
	    encrypted_len, aadlen, authlen)) != 0)
		goto out;

	/* there should be no trailing data */
	if ((r = sshbuf_consume(encoded, encrypted_len + authlen)) != 0)
		goto out;
	if (sshbuf_len(encoded) != 0) {
		r = SSH_ERR_INVALID_FORMAT;
		goto out;
	}

	/* remove AAD */
	if ((r = sshbuf_consume(decrypted, aadlen)) != 0)
		goto out;
	/* XXX encrypted includes unchecked padding */

	/* success */
	r = 0;
	if (retp != NULL) {
		*retp = decrypted;
		decrypted = NULL;
	}
 out:
	cipher_free(ciphercontext);
	sshbuf_free(copy);
	sshbuf_free(decrypted);
	free(iv);
	return r;
}
Ejemplo n.º 17
0
Archivo: kex.c Proyecto: sambuc/netbsd
static int
kex_choose_conf(struct ssh *ssh)
{
	struct kex *kex = ssh->kex;
	struct newkeys *newkeys;
	char **my = NULL, **peer = NULL;
	char **cprop, **sprop;
	int nenc, nmac, ncomp;
	u_int mode, ctos, need, dh_need, authlen;
	int log_flag = 0;
	int r, first_kex_follows;

	if ((r = kex_buf2prop(kex->my, NULL, &my)) != 0 ||
	    (r = kex_buf2prop(kex->peer, &first_kex_follows, &peer)) != 0)
		goto out;

	if (kex->server) {
		cprop=peer;
		sprop=my;
	} else {
		cprop=my;
		sprop=peer;
	}

	/* Check whether server offers roaming */
	if (!kex->server) {
		char *roaming = match_list(KEX_RESUME,
		    peer[PROPOSAL_KEX_ALGS], NULL);

		if (roaming) {
			kex->roaming = 1;
			free(roaming);
		}
	}

	/* Algorithm Negotiation */
	for (mode = 0; mode < MODE_MAX; mode++) {
		if ((newkeys = calloc(1, sizeof(*newkeys))) == NULL) {
			r = SSH_ERR_ALLOC_FAIL;
			goto out;
		}
		kex->newkeys[mode] = newkeys;
		ctos = (!kex->server && mode == MODE_OUT) ||
		    (kex->server && mode == MODE_IN);
		nenc  = ctos ? PROPOSAL_ENC_ALGS_CTOS  : PROPOSAL_ENC_ALGS_STOC;
		nmac  = ctos ? PROPOSAL_MAC_ALGS_CTOS  : PROPOSAL_MAC_ALGS_STOC;
		ncomp = ctos ? PROPOSAL_COMP_ALGS_CTOS : PROPOSAL_COMP_ALGS_STOC;
		if ((r = choose_enc(&newkeys->enc, cprop[nenc],
		    sprop[nenc])) != 0) {
			kex->failed_choice = peer[nenc];
			peer[nenc] = NULL;
			goto out;
		}
		authlen = cipher_authlen(newkeys->enc.cipher);
		/* ignore mac for authenticated encryption */
		if (authlen == 0 &&
		    (r = choose_mac(ssh, &newkeys->mac, cprop[nmac],
		    sprop[nmac])) != 0) {
			kex->failed_choice = peer[nmac];
			peer[nmac] = NULL;
			goto out;
		}
		if ((r = choose_comp(&newkeys->comp, cprop[ncomp],
		    sprop[ncomp])) != 0) {
			kex->failed_choice = peer[ncomp];
			peer[ncomp] = NULL;
			goto out;
		}
		debug("REQUESTED ENC.NAME is '%s'", newkeys->enc.name);
		if (strcmp(newkeys->enc.name, "none") == 0) {
			int auth_flag;

			auth_flag = ssh_packet_authentication_state();
			debug("Requesting NONE. Authflag is %d", auth_flag);			
			if (auth_flag == 1) {
				debug("None requested post authentication.");
			} else {
				fatal("Pre-authentication none cipher requests are not allowed.");
			}
		} 
		debug("kex: %s %s %s %s",
		    ctos ? "client->server" : "server->client",
		    newkeys->enc.name,
		    authlen == 0 ? newkeys->mac.name : "<implicit>",
		    newkeys->comp.name);
		/* client starts withctos = 0 && log flag = 0 and no log*/
		/* 2nd client pass ctos=1 and flag = 1 so no log*/
		/* server starts with ctos =1 && log_flag = 0 so log */
		/* 2nd sever pass ctos = 1 && log flag = 1 so no log*/
		/* -cjr*/
		if (ctos && !log_flag) {
			logit("SSH: Server;Ltype: Kex;Remote: %s-%d;Enc: %s;MAC: %s;Comp: %s",
			      get_remote_ipaddr(),
			      get_remote_port(),
			      newkeys->enc.name,
			      newkeys->mac.name,
			      newkeys->comp.name);
		}
		log_flag = 1;
	}
	if ((r = choose_kex(kex, cprop[PROPOSAL_KEX_ALGS],
	    sprop[PROPOSAL_KEX_ALGS])) != 0) {
		kex->failed_choice = peer[PROPOSAL_KEX_ALGS];
		peer[PROPOSAL_KEX_ALGS] = NULL;
		goto out;
	}
	if ((r = choose_hostkeyalg(kex, cprop[PROPOSAL_SERVER_HOST_KEY_ALGS],
	    sprop[PROPOSAL_SERVER_HOST_KEY_ALGS])) != 0) {
		kex->failed_choice = peer[PROPOSAL_SERVER_HOST_KEY_ALGS];
		peer[PROPOSAL_SERVER_HOST_KEY_ALGS] = NULL;
		goto out;
	}
	need = dh_need = 0;
	for (mode = 0; mode < MODE_MAX; mode++) {
		newkeys = kex->newkeys[mode];
		need = MAX(need, newkeys->enc.key_len);
		need = MAX(need, newkeys->enc.block_size);
		need = MAX(need, newkeys->enc.iv_len);
		need = MAX(need, newkeys->mac.key_len);
		dh_need = MAX(dh_need, cipher_seclen(newkeys->enc.cipher));
		dh_need = MAX(dh_need, newkeys->enc.block_size);
		dh_need = MAX(dh_need, newkeys->enc.iv_len);
		dh_need = MAX(dh_need, newkeys->mac.key_len);
	}
	/* XXX need runden? */
	kex->we_need = need;
	kex->dh_need = dh_need;

	/* ignore the next message if the proposals do not match */
	if (first_kex_follows && !proposals_match(my, peer) &&
	    !(ssh->compat & SSH_BUG_FIRSTKEX))
		ssh->dispatch_skip_packets = 1;
	r = 0;
 out:
	kex_prop_free(my);
	kex_prop_free(peer);
	return r;
}
Ejemplo n.º 18
0
int
cipher_init(struct sshcipher_ctx **ccp, const struct sshcipher *cipher,
    const u_char *key, u_int keylen, const u_char *iv, u_int ivlen,
    int do_encrypt)
{
	struct sshcipher_ctx *cc = NULL;
	int ret = SSH_ERR_INTERNAL_ERROR;
#ifdef WITH_OPENSSL
	const EVP_CIPHER *type;
	int klen;
	u_char *junk, *discard;
#endif

	*ccp = NULL;
	if ((cc = calloc(sizeof(*cc), 1)) == NULL)
		return SSH_ERR_ALLOC_FAIL;

	if (cipher->number == SSH_CIPHER_DES) {
		if (keylen > 8)
			keylen = 8;
	}

	cc->plaintext = (cipher->number == SSH_CIPHER_NONE);
	cc->encrypt = do_encrypt;

	if (keylen < cipher->key_len ||
	    (iv != NULL && ivlen < cipher_ivlen(cipher))) {
		ret = SSH_ERR_INVALID_ARGUMENT;
		goto out;
	}

	cc->cipher = cipher;
	if ((cc->cipher->flags & CFLAG_CHACHAPOLY) != 0) {
		ret = chachapoly_init(&cc->cp_ctx, key, keylen);
		goto out;
	}
#ifndef WITH_OPENSSL
	if ((cc->cipher->flags & CFLAG_AESCTR) != 0) {
		aesctr_keysetup(&cc->ac_ctx, key, 8 * keylen, 8 * ivlen);
		aesctr_ivsetup(&cc->ac_ctx, iv);
		ret = 0;
		goto out;
	}
	if ((cc->cipher->flags & CFLAG_NONE) != 0) {
		ret = 0;
		goto out;
	}
	ret = SSH_ERR_INVALID_ARGUMENT;
	goto out;
#else /* WITH_OPENSSL */
	type = (*cipher->evptype)();
	if ((cc->evp = EVP_CIPHER_CTX_new()) == NULL) {
		ret = SSH_ERR_ALLOC_FAIL;
		goto out;
	}
	if (EVP_CipherInit(cc->evp, type, NULL, (const u_char *)iv,
	    (do_encrypt == CIPHER_ENCRYPT)) == 0) {
		ret = SSH_ERR_LIBCRYPTO_ERROR;
		goto out;
	}
	if (cipher_authlen(cipher) &&
	    !EVP_CIPHER_CTX_ctrl(cc->evp, EVP_CTRL_GCM_SET_IV_FIXED,
	    -1, __UNCONST(iv))) {
		ret = SSH_ERR_LIBCRYPTO_ERROR;
		goto out;
	}
	klen = EVP_CIPHER_CTX_key_length(cc->evp);
	if (klen > 0 && keylen != (u_int)klen) {
		if (EVP_CIPHER_CTX_set_key_length(cc->evp, keylen) == 0) {
			ret = SSH_ERR_LIBCRYPTO_ERROR;
			goto out;
		}
	}
	if (EVP_CipherInit(cc->evp, NULL, __UNCONST(key), NULL, -1) == 0) {
		ret = SSH_ERR_LIBCRYPTO_ERROR;
		goto out;
	}

	if (cipher->discard_len > 0) {
		if ((junk = malloc(cipher->discard_len)) == NULL ||
		    (discard = malloc(cipher->discard_len)) == NULL) {
			free(junk);
			ret = SSH_ERR_ALLOC_FAIL;
			goto out;
		}
		ret = EVP_Cipher(cc->evp, discard, junk, cipher->discard_len);
		explicit_bzero(discard, cipher->discard_len);
		free(junk);
		free(discard);
		if (ret != 1) {
			ret = SSH_ERR_LIBCRYPTO_ERROR;
			goto out;
		}
	}
	ret = 0;
#endif /* WITH_OPENSSL */
 out:
	if (ret == 0) {
		/* success */
		*ccp = cc;
	} else {
		if (cc != NULL) {
#ifdef WITH_OPENSSL
			if (cc->evp != NULL)
				EVP_CIPHER_CTX_free(cc->evp);
#endif /* WITH_OPENSSL */
			explicit_bzero(cc, sizeof(*cc));
			free(cc);
		}
	}
	return ret;
}
Ejemplo n.º 19
0
/*
 * cipher_crypt() operates as following:
 * Copy 'aadlen' bytes (without en/decryption) from 'src' to 'dest'.
 * Theses bytes are treated as additional authenticated data for
 * authenticated encryption modes.
 * En/Decrypt 'len' bytes at offset 'aadlen' from 'src' to 'dest'.
 * Use 'authlen' bytes at offset 'len'+'aadlen' as the authentication tag.
 * This tag is written on encryption and verified on decryption.
 * Both 'aadlen' and 'authlen' can be set to 0.
 */
int
cipher_crypt(struct sshcipher_ctx *cc, u_int seqnr, u_char *dest,
   const u_char *src, u_int len, u_int aadlen, u_int authlen)
{
	if ((cc->cipher->flags & CFLAG_CHACHAPOLY) != 0) {
		return chachapoly_crypt(&cc->cp_ctx, seqnr, dest, src,
		    len, aadlen, authlen, cc->encrypt);
	}
#ifndef WITH_OPENSSL
	if ((cc->cipher->flags & CFLAG_AESCTR) != 0) {
		if (aadlen)
			memcpy(dest, src, aadlen);
		aesctr_encrypt_bytes(&cc->ac_ctx, src + aadlen,
		    dest + aadlen, len);
		return 0;
	}
	if ((cc->cipher->flags & CFLAG_NONE) != 0) {
		memcpy(dest, src, aadlen + len);
		return 0;
	}
	return SSH_ERR_INVALID_ARGUMENT;
#else
	if (authlen) {
		u_char lastiv[1];

		if (authlen != cipher_authlen(cc->cipher))
			return SSH_ERR_INVALID_ARGUMENT;
		/* increment IV */
		if (!EVP_CIPHER_CTX_ctrl(cc->evp, EVP_CTRL_GCM_IV_GEN,
		    1, lastiv))
			return SSH_ERR_LIBCRYPTO_ERROR;
		/* set tag on decyption */
		if (!cc->encrypt &&
		    !EVP_CIPHER_CTX_ctrl(cc->evp, EVP_CTRL_GCM_SET_TAG,
		    authlen, __UNCONST(src + aadlen + len)))
			return SSH_ERR_LIBCRYPTO_ERROR;
	}
	if (aadlen) {
		if (authlen &&
		    EVP_Cipher(cc->evp, NULL, (const u_char *)src, aadlen) < 0)
			return SSH_ERR_LIBCRYPTO_ERROR;
		memcpy(dest, src, aadlen);
	}
	if (len % cc->cipher->block_size)
		return SSH_ERR_INVALID_ARGUMENT;
	if (EVP_Cipher(cc->evp, dest + aadlen, (const u_char *)src + aadlen,
	    len) < 0)
		return SSH_ERR_LIBCRYPTO_ERROR;
	if (authlen) {
		/* compute tag (on encrypt) or verify tag (on decrypt) */
		if (EVP_Cipher(cc->evp, NULL, NULL, 0) < 0)
			return cc->encrypt ?
			    SSH_ERR_LIBCRYPTO_ERROR : SSH_ERR_MAC_INVALID;
		if (cc->encrypt &&
		    !EVP_CIPHER_CTX_ctrl(cc->evp, EVP_CTRL_GCM_GET_TAG,
		    authlen, dest + aadlen + len))
			return SSH_ERR_LIBCRYPTO_ERROR;
	}
	return 0;
#endif
}
Ejemplo n.º 20
0
int
ciphers_valid(const char *names)
{
	const Cipher *c;
	char *cipher_list, *cp;
	char *p;

	if (names == NULL || strcmp(names, "") == 0)
		return 0;
	cipher_list = cp = xstrdup(names);
	for ((p = strsep(&cp, CIPHER_SEP)); p && *p != '\0';
	    (p = strsep(&cp, CIPHER_SEP))) {
		c = cipher_by_name(p);
#ifdef NONE_CIPHER_ENABLED
		if (c == NULL || (c->number != SSH_CIPHER_SSH2 &&
		    c->number != SSH_CIPHER_NONE)) {
#else
		if (c == NULL || (c->number != SSH_CIPHER_SSH2)) {
#endif
			debug("bad cipher %s [%s]", p, names);
			free(cipher_list);
			return 0;
		}
	}
	debug3("ciphers ok: [%s]", names);
	free(cipher_list);
	return 1;
}

/*
 * Parses the name of the cipher.  Returns the number of the corresponding
 * cipher, or -1 on error.
 */

int
cipher_number(const char *name)
{
	const Cipher *c;
	if (name == NULL)
		return -1;
	for (c = ciphers; c->name != NULL; c++)
		if (strcasecmp(c->name, name) == 0)
			return c->number;
	return -1;
}

char *
cipher_name(int id)
{
	const Cipher *c = cipher_by_number(id);
	return (c==NULL) ? "<unknown>" : c->name;
}

void
cipher_init(CipherContext *cc, const Cipher *cipher,
    const u_char *key, u_int keylen, const u_char *iv, u_int ivlen,
    int do_encrypt)
{
	static int dowarn = 1;
#ifdef SSH_OLD_EVP
	EVP_CIPHER *type;
#else
	const EVP_CIPHER *type;
	int klen;
#endif
	u_char *junk, *discard;

	if (cipher->number == SSH_CIPHER_DES) {
		if (dowarn) {
			error("Warning: use of DES is strongly discouraged "
			    "due to cryptographic weaknesses");
			dowarn = 0;
		}
		if (keylen > 8)
			keylen = 8;
	}
	cc->plaintext = (cipher->number == SSH_CIPHER_NONE);
	cc->encrypt = do_encrypt;

	if (keylen < cipher->key_len)
		fatal("cipher_init: key length %d is insufficient for %s.",
		    keylen, cipher->name);
	if (iv != NULL && ivlen < cipher_ivlen(cipher))
		fatal("cipher_init: iv length %d is insufficient for %s.",
		    ivlen, cipher->name);
	cc->cipher = cipher;

	if ((cc->cipher->flags & CFLAG_CHACHAPOLY) != 0) {
		chachapoly_init(&cc->cp_ctx, key, keylen);
		return;
	}
	type = (*cipher->evptype)();
	EVP_CIPHER_CTX_init(&cc->evp);
#ifdef SSH_OLD_EVP
	if (type->key_len > 0 && type->key_len != keylen) {
		debug("cipher_init: set keylen (%d -> %d)",
		    type->key_len, keylen);
		type->key_len = keylen;
	}
	EVP_CipherInit(&cc->evp, type, (u_char *)key, (u_char *)iv,
	    (do_encrypt == CIPHER_ENCRYPT));
#else
	if (EVP_CipherInit(&cc->evp, type, NULL, (u_char *)iv,
	    (do_encrypt == CIPHER_ENCRYPT)) == 0)
		fatal("cipher_init: EVP_CipherInit failed for %s",
		    cipher->name);
	if (cipher_authlen(cipher) &&
	    !EVP_CIPHER_CTX_ctrl(&cc->evp, EVP_CTRL_GCM_SET_IV_FIXED,
	    -1, (u_char *)iv))
		fatal("cipher_init: EVP_CTRL_GCM_SET_IV_FIXED failed for %s",
		    cipher->name);
	klen = EVP_CIPHER_CTX_key_length(&cc->evp);
	if (klen > 0 && keylen != (u_int)klen) {
		debug2("cipher_init: set keylen (%d -> %d)", klen, keylen);
		if (EVP_CIPHER_CTX_set_key_length(&cc->evp, keylen) == 0)
			fatal("cipher_init: set keylen failed (%d -> %d)",
			    klen, keylen);
	}
	if (EVP_CipherInit(&cc->evp, NULL, (u_char *)key, NULL, -1) == 0)
		fatal("cipher_init: EVP_CipherInit: set key failed for %s",
		    cipher->name);
#endif

	if (cipher->discard_len > 0) {
		junk = xmalloc(cipher->discard_len);
		discard = xmalloc(cipher->discard_len);
		if (EVP_Cipher(&cc->evp, discard, junk,
		    cipher->discard_len) == 0)
			fatal("evp_crypt: EVP_Cipher failed during discard");
		explicit_bzero(discard, cipher->discard_len);
		free(junk);
		free(discard);
	}
}

/*
 * cipher_crypt() operates as following:
 * Copy 'aadlen' bytes (without en/decryption) from 'src' to 'dest'.
 * Theses bytes are treated as additional authenticated data for
 * authenticated encryption modes.
 * En/Decrypt 'len' bytes at offset 'aadlen' from 'src' to 'dest'.
 * Use 'authlen' bytes at offset 'len'+'aadlen' as the authentication tag.
 * This tag is written on encryption and verified on decryption.
 * Both 'aadlen' and 'authlen' can be set to 0.
 * cipher_crypt() returns 0 on success and -1 if the decryption integrity
 * check fails.
 */
int
cipher_crypt(CipherContext *cc, u_int seqnr, u_char *dest, const u_char *src,
    u_int len, u_int aadlen, u_int authlen)
{
	if ((cc->cipher->flags & CFLAG_CHACHAPOLY) != 0)
		return chachapoly_crypt(&cc->cp_ctx, seqnr, dest, src, len,
		    aadlen, authlen, cc->encrypt);
	if (authlen) {
		u_char lastiv[1];

		if (authlen != cipher_authlen(cc->cipher))
			fatal("%s: authlen mismatch %d", __func__, authlen);
		/* increment IV */
		if (!EVP_CIPHER_CTX_ctrl(&cc->evp, EVP_CTRL_GCM_IV_GEN,
		    1, lastiv))
			fatal("%s: EVP_CTRL_GCM_IV_GEN", __func__);
		/* set tag on decyption */
		if (!cc->encrypt &&
		    !EVP_CIPHER_CTX_ctrl(&cc->evp, EVP_CTRL_GCM_SET_TAG,
		    authlen, (u_char *)src + aadlen + len))
			fatal("%s: EVP_CTRL_GCM_SET_TAG", __func__);
	}
	if (aadlen) {
		if (authlen &&
		    EVP_Cipher(&cc->evp, NULL, (u_char *)src, aadlen) < 0)
			fatal("%s: EVP_Cipher(aad) failed", __func__);
		memcpy(dest, src, aadlen);
	}
	if (len % cc->cipher->block_size)
		fatal("%s: bad plaintext length %d", __func__, len);
	if (EVP_Cipher(&cc->evp, dest + aadlen, (u_char *)src + aadlen,
	    len) < 0)
		fatal("%s: EVP_Cipher failed", __func__);
	if (authlen) {
		/* compute tag (on encrypt) or verify tag (on decrypt) */
		if (EVP_Cipher(&cc->evp, NULL, NULL, 0) < 0) {
			if (cc->encrypt)
				fatal("%s: EVP_Cipher(final) failed", __func__);
			else
				return -1;
		}
		if (cc->encrypt &&
		    !EVP_CIPHER_CTX_ctrl(&cc->evp, EVP_CTRL_GCM_GET_TAG,
		    authlen, dest + aadlen + len))
			fatal("%s: EVP_CTRL_GCM_GET_TAG", __func__);
	}
	return 0;
}

/* Extract the packet length, including any decryption necessary beforehand */
int
cipher_get_length(CipherContext *cc, u_int *plenp, u_int seqnr,
    const u_char *cp, u_int len)
{
	if ((cc->cipher->flags & CFLAG_CHACHAPOLY) != 0)
		return chachapoly_get_length(&cc->cp_ctx, plenp, seqnr,
		    cp, len);
	if (len < 4)
		return -1;
	*plenp = get_u32(cp);
	return 0;
}

void
cipher_cleanup(CipherContext *cc)
{
	if ((cc->cipher->flags & CFLAG_CHACHAPOLY) != 0)
		explicit_bzero(&cc->cp_ctx, sizeof(cc->cp_ctx));
	else if (EVP_CIPHER_CTX_cleanup(&cc->evp) == 0)
		error("cipher_cleanup: EVP_CIPHER_CTX_cleanup failed");
}

/*
 * Selects the cipher, and keys if by computing the MD5 checksum of the
 * passphrase and using the resulting 16 bytes as the key.
 */

void
cipher_set_key_string(CipherContext *cc, const Cipher *cipher,
    const char *passphrase, int do_encrypt)
{
	u_char digest[16];

	if (ssh_digest_memory(SSH_DIGEST_MD5, passphrase, strlen(passphrase),
	    digest, sizeof(digest)) < 0)
		fatal("%s: md5 failed", __func__);

	cipher_init(cc, cipher, digest, 16, NULL, 0, do_encrypt);

	explicit_bzero(digest, sizeof(digest));
}
Ejemplo n.º 21
0
static int
kex_choose_conf(struct ssh *ssh)
{
	struct kex *kex = ssh->kex;
	struct newkeys *newkeys;
	char **my = NULL, **peer = NULL;
	char **cprop, **sprop;
	int nenc, nmac, ncomp;
	u_int mode, ctos, need, dh_need, authlen;
	int r, first_kex_follows;

	if ((r = kex_buf2prop(kex->my, NULL, &my)) != 0 ||
	    (r = kex_buf2prop(kex->peer, &first_kex_follows, &peer)) != 0)
		goto out;

	if (kex->server) {
		cprop=peer;
		sprop=my;
	} else {
		cprop=my;
		sprop=peer;
	}

	/* Check whether server offers roaming */
	if (!kex->server) {
		char *roaming = match_list(KEX_RESUME,
		    peer[PROPOSAL_KEX_ALGS], NULL);

		if (roaming) {
			kex->roaming = 1;
			free(roaming);
		}
	}

	/* Algorithm Negotiation */
	for (mode = 0; mode < MODE_MAX; mode++) {
		if ((newkeys = calloc(1, sizeof(*newkeys))) == NULL) {
			r = SSH_ERR_ALLOC_FAIL;
			goto out;
		}
		kex->newkeys[mode] = newkeys;
		ctos = (!kex->server && mode == MODE_OUT) ||
		    (kex->server && mode == MODE_IN);
		nenc  = ctos ? PROPOSAL_ENC_ALGS_CTOS  : PROPOSAL_ENC_ALGS_STOC;
		nmac  = ctos ? PROPOSAL_MAC_ALGS_CTOS  : PROPOSAL_MAC_ALGS_STOC;
		ncomp = ctos ? PROPOSAL_COMP_ALGS_CTOS : PROPOSAL_COMP_ALGS_STOC;
		if ((r = choose_enc(&newkeys->enc, cprop[nenc],
		    sprop[nenc])) != 0)
			goto out;
		authlen = cipher_authlen(newkeys->enc.cipher);
		/* ignore mac for authenticated encryption */
		if (authlen == 0 &&
		    (r = choose_mac(ssh, &newkeys->mac, cprop[nmac],
		    sprop[nmac])) != 0)
			goto out;
		if ((r = choose_comp(&newkeys->comp, cprop[ncomp],
		    sprop[ncomp])) != 0)
			goto out;
		debug("kex: %s %s %s %s",
		    ctos ? "client->server" : "server->client",
		    newkeys->enc.name,
		    authlen == 0 ? newkeys->mac.name : "<implicit>",
		    newkeys->comp.name);
	}
	if ((r = choose_kex(kex, cprop[PROPOSAL_KEX_ALGS],
	    sprop[PROPOSAL_KEX_ALGS])) != 0 ||
	    (r = choose_hostkeyalg(kex, cprop[PROPOSAL_SERVER_HOST_KEY_ALGS],
	    sprop[PROPOSAL_SERVER_HOST_KEY_ALGS])) != 0)
		goto out;
	need = dh_need = 0;
	for (mode = 0; mode < MODE_MAX; mode++) {
		newkeys = kex->newkeys[mode];
		need = MAX(need, newkeys->enc.key_len);
		need = MAX(need, newkeys->enc.block_size);
		need = MAX(need, newkeys->enc.iv_len);
		need = MAX(need, newkeys->mac.key_len);
		dh_need = MAX(dh_need, cipher_seclen(newkeys->enc.cipher));
		dh_need = MAX(dh_need, newkeys->enc.block_size);
		dh_need = MAX(dh_need, newkeys->enc.iv_len);
		dh_need = MAX(dh_need, newkeys->mac.key_len);
	}
	/* XXX need runden? */
	kex->we_need = need;
	kex->dh_need = dh_need;

	/* ignore the next message if the proposals do not match */
	if (first_kex_follows && !proposals_match(my, peer) &&
	    !(ssh->compat & SSH_BUG_FIRSTKEX))
		ssh->skip_packets = 1;
	r = 0;
 out:
	kex_prop_free(my);
	kex_prop_free(peer);
	return r;
}
Ejemplo n.º 22
0
void
cipher_init(CipherContext *cc, const Cipher *cipher,
    const u_char *key, u_int keylen, const u_char *iv, u_int ivlen,
    int do_encrypt)
{
	static int dowarn = 1;
	const EVP_CIPHER *type;
	int klen;
	u_char *junk, *discard;

	if (cipher->number == SSH_CIPHER_DES) {
		if (dowarn) {
			error("Warning: use of DES is strongly discouraged "
			    "due to cryptographic weaknesses");
			dowarn = 0;
		}
		if (keylen > 8)
			keylen = 8;
	}
	cc->plaintext = (cipher->number == SSH_CIPHER_NONE);
	cc->encrypt = do_encrypt;

	if (keylen < cipher->key_len)
		fatal("cipher_init: key length %d is insufficient for %s.",
		    keylen, cipher->name);
	if (iv != NULL && ivlen < cipher_ivlen(cipher))
		fatal("cipher_init: iv length %d is insufficient for %s.",
		    ivlen, cipher->name);
	cc->cipher = cipher;

	type = (*cipher->evptype)();

	EVP_CIPHER_CTX_init(&cc->evp);
	if (EVP_CipherInit(&cc->evp, type, NULL, __UNCONST(iv),
	    (do_encrypt == CIPHER_ENCRYPT)) == 0)
		fatal("cipher_init: EVP_CipherInit failed for %s",
		    cipher->name);
	if (cipher_authlen(cipher) &&
	    !EVP_CIPHER_CTX_ctrl(&cc->evp, EVP_CTRL_GCM_SET_IV_FIXED,
	    -1, __UNCONST(iv)))
		fatal("cipher_init: EVP_CTRL_GCM_SET_IV_FIXED failed for %s",
		    cipher->name);
	klen = EVP_CIPHER_CTX_key_length(&cc->evp);
	if (klen > 0 && keylen != (u_int)klen) {
		debug2("cipher_init: set keylen (%d -> %d)", klen, keylen);
		if (EVP_CIPHER_CTX_set_key_length(&cc->evp, keylen) == 0)
			fatal("cipher_init: set keylen failed (%d -> %d)",
			    klen, keylen);
	}
	if (EVP_CipherInit(&cc->evp, NULL, __UNCONST(key), NULL, -1) == 0)
		fatal("cipher_init: EVP_CipherInit: set key failed for %s",
		    cipher->name);

	if (cipher->discard_len > 0) {
		junk = xmalloc(cipher->discard_len);
		discard = xmalloc(cipher->discard_len);
		if (EVP_Cipher(&cc->evp, discard, junk,
		    cipher->discard_len) == 0)
			fatal("evp_crypt: EVP_Cipher failed during discard");
		memset(discard, 0, cipher->discard_len);
		free(junk);
		free(discard);
	}
}