Mercurial > dropbear
diff cli-authpubkey.c @ 45:9ee8996a375f
Pubkey auth is mostly there for the client. Something strange with
remote hostkey verification though.
author | Matt Johnston <matt@ucc.asn.au> |
---|---|
date | Tue, 03 Aug 2004 17:26:56 +0000 |
parents | |
children | 4b53a43f0082 |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/cli-authpubkey.c Tue Aug 03 17:26:56 2004 +0000 @@ -0,0 +1,146 @@ +#include "includes.h" +#include "buffer.h" +#include "dbutil.h" +#include "session.h" +#include "ssh.h" +#include "runopts.h" +#include "auth.h" + +static void send_msg_userauth_pubkey(sign_key *key, int type, int realsign); + +/* Called when we receive a SSH_MSG_USERAUTH_FAILURE for a pubkey request. + * We use it to remove the key we tried from the list */ +void cli_pubkeyfail() { + + struct PubkeyList *keyitem; + + TRACE(("enter cli_pubkeyfail")); + /* Find the key we failed with, and remove it */ + for (keyitem = cli_ses.pubkeys; keyitem != NULL; keyitem = keyitem->next) { + if (keyitem->next == cli_ses.lastpubkey) { + keyitem->next = cli_ses.lastpubkey->next; + } + } + + sign_key_free(cli_ses.lastpubkey->key); /* It won't be used again */ + m_free(cli_ses.lastpubkey); + TRACE(("leave cli_pubkeyfail")); +} + +void recv_msg_userauth_pk_ok() { + + struct PubkeyList *keyitem; + buffer* keybuf; + char* algotype = NULL; + unsigned int algolen; + int keytype; + unsigned int remotelen; + + TRACE(("enter recv_msg_userauth_pk_ok")); + + algotype = buf_getstring(ses.payload, &algolen); + keytype = signkey_type_from_name(algotype, algolen); + m_free(algotype); + + keybuf = buf_new(MAX_PUBKEY_SIZE); + + remotelen = buf_getint(ses.payload); + + /* Iterate through our keys, find which one it was that matched, and + * send a real request with that key */ + for (keyitem = cli_ses.pubkeys; keyitem != NULL; keyitem = keyitem->next) { + + if (keyitem->type != keytype) { + /* Types differed */ + continue; + } + + /* Now we compare the contents of the key */ + keybuf->pos = keybuf->len = 0; + buf_put_pub_key(keybuf, keyitem->key, keytype); + + if (keybuf->len != remotelen) { + /* Lengths differed */ + continue; + } + + if (memcmp(keybuf->data, + buf_getptr(ses.payload, remotelen), remotelen) != 0) { + /* Data didn't match this key */ + continue; + } + + /* Success */ + break; + } + + if (keyitem != NULL) { + TRACE(("matching key")); + /* XXX TODO: if it's an encrypted key, here we ask for their + * password */ + send_msg_userauth_pubkey(keyitem->key, keytype, 1); + } else { + TRACE(("That was whacky. We got told that a key was valid, but it didn't match our list. Sounds like dodgy code on Dropbear's part")); + } + + TRACE(("leave recv_msg_userauth_pk_ok")); +} + +/* TODO: make it take an agent reference to use as well */ +static void send_msg_userauth_pubkey(sign_key *key, int type, int realsign) { + + const char *algoname = NULL; + int algolen; + buffer* sigbuf = NULL; + + TRACE(("enter send_msg_userauth_pubkey")); + CHECKCLEARTOWRITE(); + + buf_putbyte(ses.writepayload, SSH_MSG_USERAUTH_REQUEST); + + buf_putstring(ses.writepayload, cli_opts.username, + strlen(cli_opts.username)); + + buf_putstring(ses.writepayload, SSH_SERVICE_CONNECTION, + SSH_SERVICE_CONNECTION_LEN); + + buf_putstring(ses.writepayload, AUTH_METHOD_PUBKEY, + AUTH_METHOD_PUBKEY_LEN); + + buf_putbyte(ses.writepayload, realsign); + + algoname = signkey_name_from_type(type, &algolen); + + buf_putstring(ses.writepayload, algoname, algolen); + buf_put_pub_key(ses.writepayload, key, type); + + if (realsign) { + TRACE(("realsign")); + /* We put the signature as well - this contains string(session id), then + * the contents of the write payload to this point */ + sigbuf = buf_new(4 + SHA1_HASH_SIZE + ses.writepayload->len); + buf_putstring(sigbuf, ses.session_id, SHA1_HASH_SIZE); + buf_putbytes(sigbuf, ses.writepayload->data, ses.writepayload->len); + buf_put_sign(ses.writepayload, key, type, sigbuf->data, sigbuf->len); + buf_free(sigbuf); /* Nothing confidential in the buffer */ + } + + encrypt_packet(); + TRACE(("leave send_msg_userauth_pubkey")); +} + +int cli_auth_pubkey() { + + TRACE(("enter cli_auth_pubkey")); + + if (cli_ses.pubkeys != NULL) { + /* Send a trial request */ + send_msg_userauth_pubkey(cli_ses.pubkeys->key, + cli_ses.pubkeys->type, 0); + TRACE(("leave cli_auth_pubkey-success")); + return 1; + } else { + TRACE(("leave cli_auth_pubkey-failure")); + return 0; + } +}