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#
#
# patch "cli-auth.c"
# from [3b308d18cc57b0b95f782bc7e4d8ea118a974343]
# to [1198660d36f346fbdfc05c750a7600e7f0868ecc]
#
# patch "common-algo.c"
# from [a54999708e3805153b7f6857ce09f86ea3ad41e8]
# to [4db3bb3e661b2a1b4ba9c231158e66cee69881fd]
#
# patch "common-kex.c"
# from [b06f424fe466a6d3ecfb7072d59457ebb39c8780]
# to [4e9950081bea15275c43584d533f82ac4e03c700]
#
# patch "options.h"
# from [c365717890e92696dd8e3f5821531993ec37ff35]
# to [8296b8aab905a8a55dc0e34e9b313d63bf24ec08]
#
============================================================
--- cli-auth.c 3b308d18cc57b0b95f782bc7e4d8ea118a974343
+++ cli-auth.c 1198660d36f346fbdfc05c750a7600e7f0868ecc
@@ -251,7 +251,10 @@ void cli_auth_try() {
#endif
#ifdef ENABLE_CLI_INTERACT_AUTH
- if (!finished && ses.authstate.authtypes & AUTH_TYPE_INTERACT) {
+ if (ses.keys->trans_algo_crypt->cipherdesc == NULL) {
+ fprintf(stderr, "Sorry, I won't let you use interactive auth unencrypted.\n");
+ }
+ else if (!finished && ses.authstate.authtypes & AUTH_TYPE_INTERACT) {
if (cli_ses.auth_interact_failed) {
finished = 0;
} else {
@@ -263,7 +266,10 @@ void cli_auth_try() {
#endif
#ifdef ENABLE_CLI_PASSWORD_AUTH
- if (!finished && ses.authstate.authtypes & AUTH_TYPE_PASSWORD) {
+ if (ses.keys->trans_algo_crypt->cipherdesc == NULL) {
+ fprintf(stderr, "Sorry, I won't let you use password auth unencrypted.\n");
+ }
+ else if (!finished && ses.authstate.authtypes & AUTH_TYPE_PASSWORD) {
cli_auth_password();
finished = 1;
cli_ses.lastauthtype = AUTH_TYPE_PASSWORD;
============================================================
--- common-algo.c a54999708e3805153b7f6857ce09f86ea3ad41e8
+++ common-algo.c 4db3bb3e661b2a1b4ba9c231158e66cee69881fd
@@ -103,6 +103,9 @@ algo_type sshciphers[] = {
#ifdef DROPBEAR_BLOWFISH_CBC
{"blowfish-cbc", 0, (void*)&dropbear_blowfish, 1},
#endif
+#ifdef DROPBEAR_NONE_CIPHER
+ {"none", 0, (void*)&dropbear_nocipher, 1},
+#endif
{NULL, 0, NULL, 0}
};
@@ -116,6 +119,9 @@ algo_type sshhashes[] = {
#ifdef DROPBEAR_MD5_HMAC
{"hmac-md5", 0, (void*)&dropbear_md5, 1},
#endif
+#ifdef DROPBEAR_NONE_INTEGRITY
+ {"none", 0, (void*)&dropbear_nohash, 1},
+#endif
{NULL, 0, NULL, 0}
};
============================================================
--- common-kex.c b06f424fe466a6d3ecfb7072d59457ebb39c8780
+++ common-kex.c 4e9950081bea15275c43584d533f82ac4e03c700
@@ -298,27 +298,35 @@ void gen_new_keys() {
hashkeys(C2S_key, C2S_keysize, &hs, 'C');
hashkeys(S2C_key, S2C_keysize, &hs, 'D');
- if (cbc_start(
- find_cipher(ses.newkeys->recv_algo_crypt->cipherdesc->name),
- recv_IV, recv_key,
- ses.newkeys->recv_algo_crypt->keysize, 0,
- &ses.newkeys->recv_symmetric_struct) != CRYPT_OK) {
- dropbear_exit("crypto error");
+ if (ses.newkeys->recv_algo_crypt->cipherdesc != NULL) {
+ if (cbc_start(
+ find_cipher(ses.newkeys->recv_algo_crypt->cipherdesc->name),
+ recv_IV, recv_key,
+ ses.newkeys->recv_algo_crypt->keysize, 0,
+ &ses.newkeys->recv_symmetric_struct) != CRYPT_OK) {
+ dropbear_exit("crypto error");
+ }
}
- if (cbc_start(
- find_cipher(ses.newkeys->trans_algo_crypt->cipherdesc->name),
- trans_IV, trans_key,
- ses.newkeys->trans_algo_crypt->keysize, 0,
- &ses.newkeys->trans_symmetric_struct) != CRYPT_OK) {
- dropbear_exit("crypto error");
+ if (ses.newkeys->trans_algo_crypt->cipherdesc != NULL) {
+ if (cbc_start(
+ find_cipher(ses.newkeys->trans_algo_crypt->cipherdesc->name),
+ trans_IV, trans_key,
+ ses.newkeys->trans_algo_crypt->keysize, 0,
+ &ses.newkeys->trans_symmetric_struct) != CRYPT_OK) {
+ dropbear_exit("crypto error");
+ }
}
/* MAC keys */
- hashkeys(ses.newkeys->transmackey,
- ses.newkeys->trans_algo_mac->keysize, &hs, mactransletter);
- hashkeys(ses.newkeys->recvmackey,
- ses.newkeys->recv_algo_mac->keysize, &hs, macrecvletter);
+ if (ses.newkeys->trans_algo_mac->hashdesc != NULL) {
+ hashkeys(ses.newkeys->transmackey,
+ ses.newkeys->trans_algo_mac->keysize, &hs, mactransletter);
+ }
+ if (ses.newkeys->recv_algo_mac->hashdesc != NULL) {
+ hashkeys(ses.newkeys->recvmackey,
+ ses.newkeys->recv_algo_mac->keysize, &hs, macrecvletter);
+ }
#ifndef DISABLE_ZLIB
gen_new_zstreams();
============================================================
--- options.h c365717890e92696dd8e3f5821531993ec37ff35
+++ options.h 8296b8aab905a8a55dc0e34e9b313d63bf24ec08
@@ -65,13 +65,27 @@ etc) slower (perhaps by 50%). Recommende
* RFC Draft requires 3DES and recommends AES128 for interoperability.
* Including multiple keysize variants the same cipher
* (eg AES256 as well as AES128) will result in a minimal size increase.*/
+/*
#define DROPBEAR_AES128_CBC
#define DROPBEAR_3DES_CBC
#define DROPBEAR_AES256_CBC
#define DROPBEAR_BLOWFISH_CBC
#define DROPBEAR_TWOFISH256_CBC
#define DROPBEAR_TWOFISH128_CBC
+*/
+/* You can compile with no encryption if you want. In some circumstances
+ * this could be safe securitywise, though make sure you know what
+ * you're doing. Anyone can see everything that goes over the wire, so
+ * the only safe auth method is public key. You'll have to disable all other
+ * ciphers above in the client if you want to use this, or implement cipher
+ * prioritisation in cli-runopts.
+ *
+ * The best way to do things is probably make normal compile of dropbear with all
+ * ciphers including "none" as the server, then recompile a special
+ * "dbclient-insecure" client. */
+#define DROPBEAR_NONE_CIPHER
+
/* Message Integrity - at least one required.
* RFC Draft requires sha1 and recommends sha1-96.
* sha1-96 may be of use for slow links, as it has a smaller overhead.
@@ -88,6 +102,12 @@ etc) slower (perhaps by 50%). Recommende
#define DROPBEAR_SHA1_96_HMAC
#define DROPBEAR_MD5_HMAC
+/* You can also disable integrity. Don't bother disabling this if you're
+ * still using a cipher, it's relatively cheap. Don't disable this if you're
+ * using 'none' cipher, since it's dead simple to run arbitrary commands
+ * on the remote host. Go ahead. Hang yourself with your own rope. */
+/*#define DROPBEAR_NONE_INTEGRITY*/
+
/* Hostkey/public key algorithms - at least one required, these are used
* for hostkey as well as for verifying signatures with pubkey auth.
* Removing either of these won't save very much space.