From c6d01588312bec7691e72b42cf20c59ffe2749c2 Mon Sep 17 00:00:00 2001 From: Guus Sliepen Date: Wed, 20 Feb 2002 19:25:09 +0000 Subject: [PATCH] Protocol now also exchanges cipher/digest/maclength/compression for the meta connection. --- src/connection.h | 12 ++++-- src/net_setup.c | 10 ++++- src/net_socket.c | 10 ++++- src/protocol_auth.c | 94 +++++++++++++++++++++++++++++++++++---------- src/protocol_key.c | 8 ++-- 5 files changed, 104 insertions(+), 30 deletions(-) diff --git a/src/connection.h b/src/connection.h index 436f192a..0cdcc091 100644 --- a/src/connection.h +++ b/src/connection.h @@ -17,7 +17,7 @@ along with this program; if not, write to the Free Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. - $Id: connection.h,v 1.1.2.25 2002/02/18 16:25:16 guus Exp $ + $Id: connection.h,v 1.1.2.26 2002/02/20 19:25:09 guus Exp $ */ #ifndef __TINC_CONNECTION_H__ @@ -80,14 +80,20 @@ typedef struct connection_t { struct edge_t *edge; /* edge associated with this connection */ RSA *rsa_key; /* his public/private key */ - EVP_CIPHER *incipher; /* Cipher he will use to send data to us */ - EVP_CIPHER *outcipher; /* Cipher we will use to send data to him */ + const EVP_CIPHER *incipher; /* Cipher he will use to send data to us */ + const EVP_CIPHER *outcipher; /* Cipher we will use to send data to him */ EVP_CIPHER_CTX *inctx; /* Context of encrypted meta data that will come from him to us */ EVP_CIPHER_CTX *outctx; /* Context of encrypted meta data that will be sent from us to him */ char *inkey; /* His symmetric meta key + iv */ char *outkey; /* Our symmetric meta key + iv */ int inkeylength; /* Length of his key + iv */ int outkeylength; /* Length of our key + iv */ + const EVP_MD *indigest; + const EVP_MD *outdigest; + int inmaclength; + int outmaclength; + int incompression; + int outcompression; char *mychallenge; /* challenge we received from him */ char *hischallenge; /* challenge we sent to him */ diff --git a/src/net_setup.c b/src/net_setup.c index 757121ae..3699292d 100644 --- a/src/net_setup.c +++ b/src/net_setup.c @@ -17,7 +17,7 @@ along with this program; if not, write to the Free Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. - $Id: net_setup.c,v 1.1.2.2 2002/02/20 16:04:39 guus Exp $ + $Id: net_setup.c,v 1.1.2.3 2002/02/20 19:25:09 guus Exp $ */ #include "config.h" @@ -382,6 +382,8 @@ cp else myself->keylength = 1; + myself->connection->outcipher = EVP_bf_ofb(); + myself->key = (char *)xmalloc(myself->keylength); RAND_pseudo_bytes(myself->key, myself->keylength); @@ -410,6 +412,8 @@ cp else myself->digest = EVP_sha1(); + myself->connection->outdigest = EVP_sha1(); + if(get_config_int(lookup_config(myself->connection->config_tree, "MACLength"), &myself->maclength)) { if(myself->digest) @@ -429,6 +433,8 @@ cp else myself->maclength = 4; + myself->connection->outmaclength = 0; + /* Compression */ if(get_config_int(lookup_config(myself->connection->config_tree, "Compression"), &myself->compression)) @@ -441,6 +447,8 @@ cp } else myself->compression = 0; + + myself->connection->outcompression = 0; cp /* Done */ diff --git a/src/net_socket.c b/src/net_socket.c index 93314fb6..9ce3fae0 100644 --- a/src/net_socket.c +++ b/src/net_socket.c @@ -17,7 +17,7 @@ along with this program; if not, write to the Free Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. - $Id: net_socket.c,v 1.1.2.1 2002/02/18 16:25:16 guus Exp $ + $Id: net_socket.c,v 1.1.2.2 2002/02/20 19:25:09 guus Exp $ */ #include "config.h" @@ -375,6 +375,10 @@ cp c = new_connection(); c->name = xstrdup(outgoing->name); + c->outcipher = myself->connection->outcipher; + c->outdigest = myself->connection->outdigest; + c->outmaclength = myself->connection->outmaclength; + c->outcompression = myself->connection->outcompression; init_configuration(&c->config_tree); read_connection_config(c); @@ -415,6 +419,10 @@ cp } c = new_connection(); + c->outcipher = myself->connection->outcipher; + c->outdigest = myself->connection->outdigest; + c->outmaclength = myself->connection->outmaclength; + c->outcompression = myself->connection->outcompression; c->address = sa; c->hostname = sockaddr2hostname(&sa); diff --git a/src/protocol_auth.c b/src/protocol_auth.c index 8541d3da..e37d7671 100644 --- a/src/protocol_auth.c +++ b/src/protocol_auth.c @@ -17,7 +17,7 @@ along with this program; if not, write to the Free Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. - $Id: protocol_auth.c,v 1.1.4.2 2002/02/18 16:25:16 guus Exp $ + $Id: protocol_auth.c,v 1.1.4.3 2002/02/20 19:25:09 guus Exp $ */ #include "config.h" @@ -195,15 +195,20 @@ cp /* Send the meta key */ - x = send_request(c, "%d %s", METAKEY, buffer); + x = send_request(c, "%d %d %d %d %d %s", METAKEY, + c->outcipher?c->outcipher->nid:0, c->outdigest?c->outdigest->type:0, + c->outmaclength, c->outcompression, buffer); /* Further outgoing requests are encrypted with the key we just generated */ - EVP_EncryptInit(c->outctx, EVP_bf_cfb(), - c->outkey + len - EVP_bf_cfb()->key_len, - c->outkey + len - EVP_bf_cfb()->key_len - EVP_bf_cfb()->iv_len); + if(c->outcipher) + { + EVP_EncryptInit(c->outctx, c->outcipher, + c->outkey + len - c->outcipher->key_len, + c->outkey + len - c->outcipher->key_len - c->outcipher->iv_len); - c->status.encryptout = 1; + c->status.encryptout = 1; + } cp return x; } @@ -211,9 +216,10 @@ cp int metakey_h(connection_t *c) { char buffer[MAX_STRING_SIZE]; + int cipher, digest, maclength, compression; int len; cp - if(sscanf(c->buffer, "%*d "MAX_STRING, buffer) != 1) + if(sscanf(c->buffer, "%*d %d %d %d %d "MAX_STRING, &cipher, &digest, &maclength, &compression, buffer) != 5) { syslog(LOG_ERR, _("Got bad %s from %s (%s)"), "METAKEY", c->name, c->hostname); return -1; @@ -258,11 +264,51 @@ cp /* All incoming requests will now be encrypted. */ cp - EVP_DecryptInit(c->inctx, EVP_bf_cfb(), - c->inkey + len - EVP_bf_cfb()->key_len, - c->inkey + len - EVP_bf_cfb()->key_len - EVP_bf_cfb()->iv_len); - - c->status.decryptin = 1; + /* Check and lookup cipher and digest algorithms */ + + if(cipher) + { + c->incipher = EVP_get_cipherbynid(cipher); + if(!c->incipher) + { + syslog(LOG_ERR, _("%s (%s) uses unknown cipher!"), c->name, c->hostname); + return -1; + } + + EVP_DecryptInit(c->inctx, c->incipher, + c->inkey + len - c->incipher->key_len, + c->inkey + len - c->incipher->key_len - c->incipher->iv_len); + + c->status.decryptin = 1; + } + else + { + c->incipher = NULL; + } + + c->inmaclength = maclength; + + if(digest) + { + c->indigest = EVP_get_digestbynid(digest); + if(!c->indigest) + { + syslog(LOG_ERR, _("Node %s (%s) uses unknown digest!"), c->name, c->hostname); + return -1; + } + + if(c->inmaclength > c->indigest->md_size || c->inmaclength < 0) + { + syslog(LOG_ERR, _("%s (%s) uses bogus MAC length!"), c->name, c->hostname); + return -1; + } + } + else + { + c->indigest = NULL; + } + + c->incompression = compression; c->allow_request = CHALLENGE; cp @@ -340,16 +386,19 @@ cp int send_chal_reply(connection_t *c) { - char hash[SHA_DIGEST_LENGTH*2+1]; + char hash[EVP_MAX_MD_SIZE*2+1]; + EVP_MD_CTX ctx; cp /* Calculate the hash from the challenge we received */ - SHA1(c->mychallenge, RSA_size(myself->connection->rsa_key), hash); + EVP_DigestInit(&ctx, c->indigest); + EVP_DigestUpdate(&ctx, c->mychallenge, RSA_size(myself->connection->rsa_key)); + EVP_DigestFinal(&ctx, hash, NULL); /* Convert the hash to a hexadecimal formatted string */ - bin2hex(hash,hash,SHA_DIGEST_LENGTH); - hash[SHA_DIGEST_LENGTH*2] = '\0'; + bin2hex(hash,hash,c->indigest->md_size); + hash[c->indigest->md_size*2] = '\0'; /* Send the reply */ @@ -360,7 +409,8 @@ cp int chal_reply_h(connection_t *c) { char hishash[MAX_STRING_SIZE]; - char myhash[SHA_DIGEST_LENGTH]; + char myhash[EVP_MAX_MD_SIZE]; + EVP_MD_CTX ctx; cp if(sscanf(c->buffer, "%*d "MAX_STRING, hishash) != 1) { @@ -370,7 +420,7 @@ cp /* Check if the length of the hash is all right */ - if(strlen(hishash) != SHA_DIGEST_LENGTH*2) + if(strlen(hishash) != c->outdigest->md_size*2) { syslog(LOG_ERR, _("Possible intruder %s (%s): %s"), c->name, c->hostname, _("wrong challenge reply length")); return -1; @@ -378,15 +428,17 @@ cp /* Convert the hash to binary format */ - hex2bin(hishash, hishash, SHA_DIGEST_LENGTH); + hex2bin(hishash, hishash, c->outdigest->md_size); /* Calculate the hash from the challenge we sent */ - SHA1(c->hischallenge, RSA_size(c->rsa_key), myhash); + EVP_DigestInit(&ctx, c->outdigest); + EVP_DigestUpdate(&ctx, c->hischallenge, RSA_size(c->rsa_key)); + EVP_DigestFinal(&ctx, myhash, NULL); /* Verify the incoming hash with the calculated hash */ - if(memcmp(hishash, myhash, SHA_DIGEST_LENGTH)) + if(memcmp(hishash, myhash, c->outdigest->md_size)) { syslog(LOG_ERR, _("Possible intruder %s (%s): %s"), c->name, c->hostname, _("wrong challenge reply")); if(debug_lvl >= DEBUG_SCARY_THINGS) diff --git a/src/protocol_key.c b/src/protocol_key.c index 621bb1b8..aec78899 100644 --- a/src/protocol_key.c +++ b/src/protocol_key.c @@ -17,7 +17,7 @@ along with this program; if not, write to the Free Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA. - $Id: protocol_key.c,v 1.1.4.2 2002/02/11 15:59:18 guus Exp $ + $Id: protocol_key.c,v 1.1.4.3 2002/02/20 19:25:09 guus Exp $ */ #include "config.h" @@ -41,7 +41,7 @@ #include "connection.h" #include "node.h" #include "edge.h" -\ + #include "system.h" int mykeyused = 0; @@ -245,6 +245,8 @@ cp from->cipher = NULL; } + from->maclength = maclength; + if(digest) { from->digest = EVP_get_digestbynid(digest); @@ -253,7 +255,6 @@ cp syslog(LOG_ERR, _("Node %s (%s) uses unknown digest!"), from->name, from->hostname); return -1; } - from->maclength = maclength; if(from->maclength > from->digest->md_size || from->maclength < 0) { syslog(LOG_ERR, _("Node %s (%s) uses bogus MAC length!"), from->name, from->hostname); @@ -263,7 +264,6 @@ cp else { from->digest = NULL; - from->maclength = maclength; } from->compression = compression; -- 2.39.5