New standard linked list to use, rather than adhoc SignKeyList or TCPFwdList

17 files changed, 254 insertions, 192 deletions

diff --git a/Makefile.in b/Makefile.in
index efd9e57..fe10204 100644
--- a/Makefile.in
+++ b/Makefile.in
@@ -20,7 +20,7 @@ COMMONOBJS=dbutil.o buffer.o \
 		dss.o bignum.o \
 		signkey.o rsa.o random.o \
 		queue.o \
-		atomicio.o compat.o  fake-rfc2553.o
+		atomicio.o compat.o  fake-rfc2553.o 
 
 SVROBJS=svr-kex.o svr-algo.o svr-auth.o sshpty.o \
 		svr-authpasswd.o svr-authpubkey.o svr-authpubkeyoptions.o svr-session.o svr-service.o \
@@ -30,7 +30,7 @@ SVROBJS=svr-kex.o svr-algo.o svr-auth.o sshpty.o \
 CLIOBJS=cli-algo.o cli-main.o cli-auth.o cli-authpasswd.o cli-kex.o \
 		cli-session.o cli-service.o cli-runopts.o cli-chansession.o \
 		cli-authpubkey.o cli-tcpfwd.o cli-channel.o cli-authinteract.o \
-		cli-agentfwd.o
+		cli-agentfwd.o list.o
 
 CLISVROBJS=common-session.o packet.o common-algo.o common-kex.o \
 			common-channel.o common-chansession.o termcodes.o loginrec.o \
diff --git a/agentfwd.h b/agentfwd.h
index 8575b0c..e1794a7 100644
--- a/agentfwd.h
+++ b/agentfwd.h
@@ -28,6 +28,7 @@
 #include "chansession.h"
 #include "channel.h"
 #include "auth.h"
+#include "list.h"
 
 /* An agent reply can be reasonably large, as it can
  * contain a list of all public keys held by the agent.
@@ -35,11 +36,13 @@
 #define MAX_AGENT_REPLY  10000
 
 int agentreq(struct ChanSess * chansess);
-void agentsetauth(struct ChanSess *chansess);
 void agentcleanup(struct ChanSess * chansess);
 void agentset(struct ChanSess *chansess);
 
-void load_agent_keys(struct SignKeyList * ret_list);
+/* client functions */
+void load_agent_keys(m_list * ret_list);
+void agent_buf_sign(buffer *sigblob, sign_key *key, 
+    const unsigned char *data, unsigned int len);
 
 #ifdef __hpux
 #define seteuid(a)       setresuid(-1, (a), -1)
diff --git a/auth.h b/auth.h
index a35416c..d22f812 100644
--- a/auth.h
+++ b/auth.h
@@ -124,26 +124,6 @@ struct AuthState {
 
 };
 
-/* Sources for signing keys */
-typedef enum {
-	SIGNKEY_SOURCE_RAW_FILE,
-	SIGNKEY_SOURCE_AGENT,
-} signkey_source;
-
-struct SignKeyList;
-/* A singly linked list of signing keys */
-struct SignKeyList {
-
-	sign_key *key;
-	int type; /* The type of key */
-	struct SignKeyList *next;
-	signkey_source source;
-	char *filename;
-	/* the buffer? for encrypted keys, so we can later get
-	 * the private key portion */
-
-};
-
 #ifdef ENABLE_SVR_PUBKEY_OPTIONS
 struct PubKeyOptions;
 struct PubKeyOptions {
diff --git a/buffer.c b/buffer.c
index 579fa6f..7394993 100644
--- a/buffer.c
+++ b/buffer.c
@@ -223,6 +223,20 @@ unsigned char* buf_getstring(buffer* buf, unsigned int *retlen) {
 	return ret;
 }
 
+/* Return a string as a newly allocated buffer */
+buffer * buf_getstringbuf(buffer *buf) {
+	buffer *ret;
+	unsigned char* str;
+	unsigned int len;
+	str = buf_getstring(buf, &len);
+	ret = m_malloc(sizeof(*ret));
+	ret->data = str;
+	ret->len = len;
+	ret->size = len;
+	ret->pos = 0;
+	return ret;
+}
+
 /* Just increment the buffer position the same as if we'd used buf_getstring,
  * but don't bother copying/malloc()ing for it */
 void buf_eatstring(buffer *buf) {
diff --git a/buffer.h b/buffer.h
index f9aa6fa..5964370 100644
--- a/buffer.h
+++ b/buffer.h
@@ -55,6 +55,7 @@ void buf_putbyte(buffer* buf, unsigned char val);
 unsigned char* buf_getptr(buffer* buf, unsigned int len);
 unsigned char* buf_getwriteptr(buffer* buf, unsigned int len);
 unsigned char* buf_getstring(buffer* buf, unsigned int *retlen);
+buffer * buf_getstringbuf(buffer *buf);
 void buf_eatstring(buffer *buf);
 void buf_putint(buffer* buf, unsigned int val);
 void buf_putstring(buffer* buf, const unsigned char* str, unsigned int len);
diff --git a/cli-agentfwd.c b/cli-agentfwd.c
index b47a6cc..0a5661d 100644
--- a/cli-agentfwd.c
+++ b/cli-agentfwd.c
@@ -22,10 +22,6 @@
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
  * SOFTWARE. */
 
-/* The basic protocol use to communicate with the agent is defined in
- * draft-ylonen-ssh-protocol-00.txt, with the ssh2 extensions defined through
- * openssh's implementation. */
-
 #include "includes.h"
 
 #ifdef ENABLE_CLI_AGENTFWD
@@ -45,6 +41,9 @@
 #include "signkey.h"
 #include "auth.h"
 
+/* The protocol implemented to talk to OpenSSH's SSH2 agent is documented in
+   PROTOCOL.agent in recent OpenSSH source distributions (5.1p1 has it). */
+
 static int new_agent_chan(struct Channel * channel);
 
 const struct ChanType cli_chan_agent = {
@@ -161,13 +160,12 @@ out:
 	return inbuf;
 }
 
-static void agent_get_key_list(int fd, struct SignKeyList * ret_list)
+static void agent_get_key_list(int fd, m_list * ret_list)
 {
 	buffer * inbuf = NULL;
 	unsigned int num = 0;
 	unsigned char packet_type;
 	unsigned int i;
-	struct SignKeyList *key = NULL;
 	int ret;
 
 	inbuf = agent_request(fd, SSH2_AGENTC_REQUEST_IDENTITIES);
@@ -177,14 +175,11 @@ static void agent_get_key_list(int fd, struct SignKeyList * ret_list)
 	}
 
 	/* The reply has a format of:
-	 * byte     packet_type
-	 * int      num_keys
-	 *
-	 * string    keyblob1
-	 * string    comment1
-	 * ...
-	 * string    keyblob(n)
-	 * string    comment(n)
+		byte			SSH2_AGENT_IDENTITIES_ANSWER
+		uint32			num_keys
+  	   Followed by zero or more consecutive keys, encoded as:
+       	 string			key_blob
+    	 string			key_comment
 	 */
 	packet_type = buf_getbyte(inbuf);
 	if (packet_type != SSH2_AGENT_IDENTITIES_ANSWER) {
@@ -195,25 +190,24 @@ static void agent_get_key_list(int fd, struct SignKeyList * ret_list)
 	for (i = 0; i < num; i++) {
 		sign_key * pubkey = NULL;
 		int key_type = DROPBEAR_SIGNKEY_ANY;
+		buffer * key_buf;
 		struct SignKeyList *nextkey = NULL;
 
-		nextkey = (struct SignKeyList*)m_malloc(sizeof(struct SignKeyList));
-		ret_list->next = nextkey;
-		ret_list = nextkey;
-
+		/* each public key is encoded as a string */
+		key_buf = buf_getstringbuf(inbuf);
 		pubkey = new_sign_key();
-		ret = buf_get_pub_key(inbuf, pubkey, &key_type);
+		ret = buf_get_pub_key(key_buf, pubkey, &key_type);
+		buf_free(key_buf);
 		if (ret != DROPBEAR_SUCCESS) {
 			/* This is slack, properly would cleanup vars etc */
 			dropbear_exit("Bad pubkey received from agent");
 		}
+		pubkey->type = key_type;
+		pubkey->source = SIGNKEY_SOURCE_AGENT;
 
-		key->key = pubkey;
-		key->next = NULL;
-		key->type = key_type;
-		key->source = SIGNKEY_SOURCE_AGENT;
+		list_append(ret_list, pubkey);
 
-		/* We'll ignore the comment */
+		/* We'll ignore the comment for now. might want it later.*/
 		buf_eatstring(inbuf);
 	}
 
@@ -224,8 +218,9 @@ out:
 	}
 }
 
-/* Returned keys are appended to ret_list */
-void load_agent_keys(struct SignKeyList * ret_list)
+/* Returned keys are prepended to ret_list, which will
+   be updated. */
+void load_agent_keys(m_list *ret_list)
 {
 	int fd;
 	fd = connect_agent();
@@ -237,13 +232,9 @@ void load_agent_keys(struct SignKeyList * ret_list)
 	agent_get_key_list(fd, ret_list);
 	close(fd);
 }
-	
-// general procedure:
-// - get the list of keys from the agent
-// - foreach, send a dummy userauth_pubkey message to the server and see
-// if it lets us in
-// - if it does, sign and auth
-// - if not, repeat.
-//
+
+void agent_buf_sign(buffer *sigblob, sign_key *key, 
+		const unsigned char *data, unsigned int len) {
+}
 
 #endif
diff --git a/cli-authpubkey.c b/cli-authpubkey.c
index b7ecd55..0ad0031 100644
--- a/cli-authpubkey.c
+++ b/cli-authpubkey.c
@@ -30,6 +30,7 @@
 #include "ssh.h"
 #include "runopts.h"
 #include "auth.h"
+#include "agentfwd.h"
 
 #ifdef ENABLE_CLI_PUBKEY_AUTH
 static void send_msg_userauth_pubkey(sign_key *key, int type, int realsign);
@@ -37,31 +38,23 @@ 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 SignKeyList *keyitem;
-	struct SignKeyList **previtem;
-
-	TRACE(("enter cli_pubkeyfail"))
-	previtem = &cli_opts.privkeys;
-
-	/* Find the key we failed with, and remove it */
-	for (keyitem = cli_opts.privkeys; keyitem != NULL; keyitem = keyitem->next) {
-		if (keyitem == cli_ses.lastprivkey) {
-			*previtem = keyitem->next;
+	m_list_elem *iter;
+	for (iter = cli_opts.privkeys->first; iter; iter = iter->next) {
+		sign_key *iter_key = (sign_key*)iter->item;
+		
+		if (iter_key == cli_ses.lastprivkey)
+		{
+			/* found the failing key */
+			list_remove(iter);
+			sign_key_free(iter_key);
+			cli_ses.lastprivkey = NULL;
+			return;
 		}
-		previtem = &keyitem;
 	}
-
-	sign_key_free(cli_ses.lastprivkey->key); /* It won't be used again */
-	m_free(cli_ses.lastprivkey->filename);
-	m_free(cli_ses.lastprivkey);
-
-	TRACE(("leave cli_pubkeyfail"))
 }
 
 void recv_msg_userauth_pk_ok() {
-
-	struct SignKeyList *keyitem = NULL;
+	m_list_elem *iter;
 	buffer* keybuf = NULL;
 	char* algotype = NULL;
 	unsigned int algolen;
@@ -81,9 +74,9 @@ void recv_msg_userauth_pk_ok() {
 
 	/* Iterate through our keys, find which one it was that matched, and
 	 * send a real request with that key */
-	for (keyitem = cli_opts.privkeys; keyitem != NULL; keyitem = keyitem->next) {
-
-		if (keyitem->type != keytype) {
+	for (iter = cli_opts.privkeys->first; iter; iter = iter->next) {
+		sign_key *key = (sign_key*)iter->item;
+		if (key->type != keytype) {
 			/* Types differed */
 			TRACE(("types differed"))
 			continue;
@@ -91,7 +84,7 @@ void recv_msg_userauth_pk_ok() {
 
 		/* Now we compare the contents of the key */
 		keybuf->pos = keybuf->len = 0;
-		buf_put_pub_key(keybuf, keyitem->key, keytype);
+		buf_put_pub_key(keybuf, key, keytype);
 		buf_setpos(keybuf, 0);
 		buf_incrpos(keybuf, 4); /* first int is the length of the remainder (ie
 								   remotelen) which has already been taken from
@@ -115,11 +108,11 @@ void recv_msg_userauth_pk_ok() {
 	}
 	buf_free(keybuf);
 
-	if (keyitem != NULL) {
+	if (iter != 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);
+		send_msg_userauth_pubkey((sign_key*)iter->item, 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"))
 	}
@@ -127,6 +120,25 @@ void recv_msg_userauth_pk_ok() {
 	TRACE(("leave recv_msg_userauth_pk_ok"))
 }
 
+void cli_buf_put_sign(buffer* buf, sign_key *key, int type, 
+			const unsigned char *data, unsigned int len)
+{
+	if (key->source == SIGNKEY_SOURCE_AGENT) {
+		/* Format the agent signature ourselves, as buf_put_sign would. */
+		buffer *sigblob;
+		sigblob = buf_new(MAX_PUBKEY_SIZE);
+		agent_buf_sign(sigblob, key, data, len);
+		buf_setpos(sigblob, 0);
+		buf_putstring(buf, buf_getptr(sigblob, sigblob->len),
+				sigblob->len);
+
+		buf_free(sigblob);
+	} else {
+		buf_put_sign(buf, key, type, data, len);
+	}
+	
+}
+
 /* TODO: make it take an agent reference to use as well */
 static void send_msg_userauth_pubkey(sign_key *key, int type, int realsign) {
 
@@ -170,6 +182,7 @@ static void send_msg_userauth_pubkey(sign_key *key, int type, int realsign) {
 	TRACE(("leave send_msg_userauth_pubkey"))
 }
 
+/* Returns 1 if a key was tried */
 int cli_auth_pubkey() {
 
 	TRACE(("enter cli_auth_pubkey"))
@@ -177,15 +190,15 @@ int cli_auth_pubkey() {
 	if (cli_opts.agent_fwd &&
 			!cli_opts.agent_keys_loaded) {
 		/* get the list of available keys from the agent */
-		load_agent_keys(&cli_opts.privkeys);
+		load_agent_keys(cli_opts.privkeys);
 		cli_opts.agent_keys_loaded = 1;
 	}
 
-	if (cli_opts.privkeys != NULL) {
+	if (cli_opts.privkeys->first) {
+		sign_key * key = (sign_key*)cli_opts.privkeys->first->item;
 		/* Send a trial request */
-		send_msg_userauth_pubkey(cli_opts.privkeys->key,
-				cli_opts.privkeys->type, 0);
-		cli_ses.lastprivkey = cli_opts.privkeys;
+		send_msg_userauth_pubkey(key, key->type, 0);
+		cli_ses.lastprivkey = key;
 		TRACE(("leave cli_auth_pubkey-success"))
 		return 1;
 	} else {
diff --git a/cli-chansession.c b/cli-chansession.c
index dc8e641..9dc0224 100644
--- a/cli-chansession.c
+++ b/cli-chansession.c
@@ -424,16 +424,3 @@ void cli_send_chansess_request() {
 	TRACE(("leave cli_send_chansess_request"))
 
 }
-
-
-#if 0
-	while (cli_opts.localfwds != NULL) {
-		ret = cli_localtcp(cli_opts.localfwds->listenport,
-				cli_opts.localfwds->connectaddr,
-				cli_opts.localfwds->connectport);
-		if (ret == DROPBEAR_FAILURE) {
-			dropbear_log(LOG_WARNING, "Failed local port forward %d:%s:%d",
-					cli_opts.localfwds->listenport,
-					cli_opts.localfwds->connectaddr,
-					cli_opts.localfwds->connectport);
-#endif
diff --git a/cli-runopts.c b/cli-runopts.c
index a7c0f82..eab33b7 100644
--- a/cli-runopts.c
+++ b/cli-runopts.c
@@ -29,6 +29,7 @@
 #include "dbutil.h"
 #include "algo.h"
 #include "tcpfwd.h"
+#include "list.h"
 
 cli_runopts cli_opts; /* GLOBAL */
 
@@ -40,7 +41,7 @@ static void fill_own_user();
 static void loadidentityfile(const char* filename);
 #endif
 #ifdef ENABLE_CLI_ANYTCPFWD
-static void addforward(const char* str, struct TCPFwdList** fwdlist);
+static void addforward(const char* str, m_list *fwdlist);
 #endif
 #ifdef ENABLE_CLI_NETCAT
 static void add_netcat(const char *str);
@@ -128,14 +129,14 @@ void cli_getopts(int argc, char ** argv) {
 	cli_opts.always_accept_key = 0;
 	cli_opts.is_subsystem = 0;
 #ifdef ENABLE_CLI_PUBKEY_AUTH
-	cli_opts.privkeys = NULL;
+	cli_opts.privkeys = list_new();
 #endif
 #ifdef ENABLE_CLI_LOCALTCPFWD
-	cli_opts.localfwds = NULL;
+	cli_opts.localfwds = list_new();
 	opts.listen_fwd_all = 0;
 #endif
 #ifdef ENABLE_CLI_REMOTETCPFWD
-	cli_opts.remotefwds = NULL;
+	cli_opts.remotefwds = list_new();
 #endif
 #ifdef ENABLE_CLI_AGENTFWD
 	cli_opts.agent_fwd = 0;
@@ -165,7 +166,7 @@ void cli_getopts(int argc, char ** argv) {
 #ifdef ENABLE_CLI_REMOTETCPFWD
 		if (nextisremote) {
 			TRACE(("nextisremote true"))
-			addforward(argv[i], &cli_opts.remotefwds);
+			addforward(argv[i], cli_opts.remotefwds);
 			nextisremote = 0;
 			continue;
 		}
@@ -173,7 +174,7 @@ void cli_getopts(int argc, char ** argv) {
 #ifdef ENABLE_CLI_LOCALTCPFWD
 		if (nextislocal) {
 			TRACE(("nextislocal true"))
-			addforward(argv[i], &cli_opts.localfwds);
+			addforward(argv[i], cli_opts.localfwds);
 			nextislocal = 0;
 			continue;
 		}
@@ -406,8 +407,6 @@ void cli_getopts(int argc, char ** argv) {
 
 #ifdef ENABLE_CLI_PUBKEY_AUTH
 static void loadidentityfile(const char* filename) {
-
-	struct SignKeyList * nextkey;
 	sign_key *key;
 	int keytype;
 
@@ -417,13 +416,10 @@ static void loadidentityfile(const char* filename) {
 		fprintf(stderr, "Failed loading keyfile '%s'\n", filename);
 		sign_key_free(key);
 	} else {
-		nextkey = (struct SignKeyList*)m_malloc(sizeof(struct SignKeyList));
-		nextkey->key = key;
-		nextkey->filename = m_strdup(filename);
-		nextkey->next = cli_opts.privkeys;
-		nextkey->type = keytype;
-		nextkey->source = SIGNKEY_SOURCE_RAW_FILE;
-		cli_opts.privkeys = nextkey;
+		key->type = keytype;
+		key->source = SIGNKEY_SOURCE_RAW_FILE;
+		key->filename = m_strdup(filename);
+		list_append(cli_opts.privkeys, key);
 	}
 }
 #endif
@@ -435,12 +431,13 @@ multihop_passthrough_args() {
 	char *ret;
 	int total;
 	unsigned int len = 0;
-	struct SignKeyList *nextkey;
+	m_list_elem *iter;
 	/* Fill out -i and -W options that make sense for all
 	 * the intermediate processes */
-	for (nextkey = cli_opts.privkeys; nextkey; nextkey = nextkey->next)
+	for (iter = cli_opts.privkeys->first; iter; iter = iter->next)
 	{
-		len += 3 + strlen(nextkey->filename);
+		sign_key * key = (sign_key*)iter->item;
+		len += 3 + strlen(key->filename);
 	}
 	len += 20; // space for -W <size>, terminator.
 	ret = m_malloc(len);
@@ -452,10 +449,11 @@ multihop_passthrough_args() {
 		total += written;
 	}
 
-	for (nextkey = cli_opts.privkeys; nextkey; nextkey = nextkey->next)
+	for (iter = cli_opts.privkeys->first; iter; iter = iter->next)
 	{
+		sign_key * key = (sign_key*)iter->item;
 		const size_t size = len - total;
-		int written = snprintf(ret+total, size, "-i %s", nextkey->filename);
+		int written = snprintf(ret+total, size, "-i %s", key->filename);
 		dropbear_assert(written < size);
 		total += written;
 	}
@@ -621,12 +619,12 @@ static void fill_own_user() {
 #ifdef ENABLE_CLI_ANYTCPFWD
 /* Turn a "listenport:remoteaddr:remoteport" string into into a forwarding
  * set, and add it to the forwarding list */
-static void addforward(const char* origstr, struct TCPFwdList** fwdlist) {
+static void addforward(const char* origstr, m_list *fwdlist) {
 
 	char * listenport = NULL;
 	char * connectport = NULL;
 	char * connectaddr = NULL;
-	struct TCPFwdList* newfwd = NULL;
+	struct TCPFwdEntry* newfwd = NULL;
 	char * str = NULL;
 
 	TRACE(("enter addforward"))
@@ -653,7 +651,7 @@ static void addforward(const char* origstr, struct TCPFwdList** fwdlist) {
 	*connectport = '\0';
 	connectport++;
 
-	newfwd = (struct TCPFwdList*)m_malloc(sizeof(struct TCPFwdList));
+	newfwd = m_malloc(sizeof(struct TCPFwdEntry));
 
 	/* Now we check the ports - note that the port ints are unsigned,
 	 * the check later only checks for >= MAX_PORT */
@@ -680,8 +678,7 @@ static void addforward(const char* origstr, struct TCPFwdList** fwdlist) {
 	}
 
 	newfwd->have_reply = 0;
-	newfwd->next = *fwdlist;
-	*fwdlist = newfwd;
+	list_append(fwdlist, newfwd);
 
 	TRACE(("leave addforward: done"))
 	return;
diff --git a/cli-tcpfwd.c b/cli-tcpfwd.c
index 0e60090..0242654 100644
--- a/cli-tcpfwd.c
+++ b/cli-tcpfwd.c
@@ -59,27 +59,22 @@ static const struct ChanType cli_chan_tcplocal = {
 
 #ifdef ENABLE_CLI_LOCALTCPFWD
 void setup_localtcp() {
-
+	m_list_elem *iter;
 	int ret;
 
 	TRACE(("enter setup_localtcp"))
 
-	if (cli_opts.localfwds == NULL) {
-		TRACE(("cli_opts.localfwds == NULL"))
-	}
-
-	while (cli_opts.localfwds != NULL) {
-		ret = cli_localtcp(cli_opts.localfwds->listenport,
-				cli_opts.localfwds->connectaddr,
-				cli_opts.localfwds->connectport);
+	for (iter = cli_opts.localfwds->first; iter; iter = iter->next) {
+		struct TCPFwdEntry * fwd = (struct TCPFwdEntry*)iter->item;
+		ret = cli_localtcp(fwd->listenport,
+				fwd->connectaddr,
+				fwd->connectport);
 		if (ret == DROPBEAR_FAILURE) {
 			dropbear_log(LOG_WARNING, "Failed local port forward %d:%s:%d",
-					cli_opts.localfwds->listenport,
-					cli_opts.localfwds->connectaddr,
-					cli_opts.localfwds->connectport);
-		}
-
-		cli_opts.localfwds = cli_opts.localfwds->next;
+					fwd->listenport,
+					fwd->connectaddr,
+					fwd->connectport);
+		}		
 	}
 	TRACE(("leave setup_localtcp"))
 
@@ -148,60 +143,47 @@ static void send_msg_global_request_remotetcp(int port) {
  * being in the same order as we sent the requests. This is the ordering
  * of the cli_opts.remotefwds list */
 void cli_recv_msg_request_success() {
-
 	/* Nothing in the packet. We just mark off that we have received the reply,
 	 * so that we can report failure for later ones. */
-	struct TCPFwdList * iter = NULL;
-
-	iter = cli_opts.remotefwds;
-	while (iter != NULL) {
-		if (!iter->have_reply)
-		{
-			iter->have_reply = 1;
+	m_list_elem * iter = NULL;
+	for (iter = cli_opts.remotefwds->first; iter; iter = iter->next) {
+		struct TCPFwdEntry *fwd = (struct TCPFwdEntry*)iter->item;
+		if (!fwd->have_reply) {
+			fwd->have_reply = 1;
 			return;
 		}
-		iter = iter->next;
 	}
 }
 
 void cli_recv_msg_request_failure() {
-	struct TCPFwdList * iter = NULL;
-
-	iter = cli_opts.remotefwds;
-	while (iter != NULL) {
-		if (!iter->have_reply)
-		{
-			iter->have_reply = 1;
-			dropbear_log(LOG_WARNING, "Remote TCP forward request failed (port %d -> %s:%d)", iter->listenport, iter->connectaddr, iter->connectport);
+	m_list_elem *iter;
+	for (iter = cli_opts.remotefwds->first; iter; iter = iter->next) {
+		struct TCPFwdEntry *fwd = (struct TCPFwdEntry*)iter->item;
+		if (!fwd->have_reply) {
+			fwd->have_reply = 1;
+			dropbear_log(LOG_WARNING, "Remote TCP forward request failed (port %d -> %s:%d)", fwd->listenport, fwd->connectaddr, fwd->connectport);
 			return;
 		}
-		iter = iter->next;
 	}
 }
 
 void setup_remotetcp() {
-
-	struct TCPFwdList * iter = NULL;
-
+	m_list_elem *iter;
 	TRACE(("enter setup_remotetcp"))
 
-	if (cli_opts.remotefwds == NULL) {
-		TRACE(("cli_opts.remotefwds == NULL"))
+	for (iter = cli_opts.remotefwds->first; iter; iter = iter->next) {
+		struct TCPFwdEntry *fwd = (struct TCPFwdEntry*)iter->item;
+		send_msg_global_request_remotetcp(fwd->listenport);
 	}
 
-	iter = cli_opts.remotefwds;
-
-	while (iter != NULL) {
-		send_msg_global_request_remotetcp(iter->listenport);
-		iter = iter->next;
-	}
 	TRACE(("leave setup_remotetcp"))
 }
 
 static int newtcpforwarded(struct Channel * channel) {
 
 	unsigned int origport;
-	struct TCPFwdList * iter = NULL;
+	m_list_elem * iter = NULL;
+	struct TCPFwdEntry *fwd;
 	char portstring[NI_MAXSERV];
 	int sock;
 	int err = SSH_OPEN_ADMINISTRATIVELY_PROHIBITED;
@@ -212,13 +194,11 @@ static int newtcpforwarded(struct Channel * channel) {
 	origport = buf_getint(ses.payload);
 
 	/* Find which port corresponds */
-	iter = cli_opts.remotefwds;
-
-	while (iter != NULL) {
-		if (origport == iter->listenport) {
+	for (iter = cli_opts.remotefwds->first; iter; iter = iter->next) {
+		fwd = (struct TCPFwdEntry*)iter->item;
+		if (origport == fwd->listenport) {
 			break;
 		}
-		iter = iter->next;
 	}
 
 	if (iter == NULL) {
@@ -228,8 +208,8 @@ static int newtcpforwarded(struct Channel * channel) {
 		goto out;
 	}
 	
-	snprintf(portstring, sizeof(portstring), "%d", iter->connectport);
-	sock = connect_remote(iter->connectaddr, portstring, 1, NULL);
+	snprintf(portstring, sizeof(portstring), "%d", fwd->connectport);
+	sock = connect_remote(fwd->connectaddr, portstring, 1, NULL);
 	if (sock < 0) {
 		TRACE(("leave newtcpdirect: sock failed"))
 		err = SSH_OPEN_CONNECT_FAILED;
diff --git a/list.c b/list.c
new file mode 100644
index 0000000..8be1a3a
--- /dev/null
+++ b/list.c
@@ -0,0 +1,49 @@
+#include "options.h"
+#include "dbutil.h"
+#include "list.h"
+
+void list_append(m_list *list, void *item) {
+	m_list_elem *elem;
+	
+	elem = m_malloc(sizeof(*elem));
+	elem->item = item;
+	elem->list = list;
+	elem->next = NULL;
+	if (!list->first) {
+		list->first = elem;
+		elem->prev = NULL;
+	} else {
+		elem->prev = list->last;
+		list->last->next = elem;
+	}
+	list->last = elem;
+}
+
+m_list * list_new() {
+	m_list *ret = m_malloc(sizeof(m_list));
+	ret->first = ret->last = NULL;
+	return ret;
+}
+
+void * list_remove(m_list_elem *elem) {
+	void *item = elem->item;
+	m_list *list = elem->list;
+	if (list->first == elem)
+	{
+		list->first = elem->next;
+	}
+	if (list->last == elem)
+	{
+		list->last = elem->prev;
+	}
+	if (elem->prev)
+	{
+		elem->prev->next = elem->next;
+	}
+	if (elem->next)
+	{
+		elem->next->prev = elem->prev;
+	}
+	m_free(elem);
+	return item;
+}
\ No newline at end of file
diff --git a/list.h b/list.h
new file mode 100644
index 0000000..678fff1
--- /dev/null
+++ b/list.h
@@ -0,0 +1,28 @@
+#ifndef _DROPBEAR_LIST_H
+#define _DROPBEAR_LIST_H
+
+struct _m_list;
+
+struct _m_list_elem {
+    void *item;
+	struct _m_list_elem *next;
+	struct _m_list_elem *prev;
+    struct _m_list *list;
+};
+	
+typedef struct _m_list_elem m_list_elem;
+
+struct _m_list {
+    m_list_elem *first;
+    m_list_elem *last;
+};
+
+typedef struct _m_list m_list;
+
+m_list * list_new();
+void list_append(m_list *list, void *item);
+/* returns the item for the element removed */
+void * list_remove(m_list_elem *elem);
+
+
+#endif /* _DROPBEAR_LIST_H */
\ No newline at end of file
diff --git a/runopts.h b/runopts.h
index bc35435..e672a4e 100644
--- a/runopts.h
+++ b/runopts.h
@@ -112,13 +112,13 @@ typedef struct cli_runopts {
 	int backgrounded;
 	int is_subsystem;
 #ifdef ENABLE_CLI_PUBKEY_AUTH
-	struct SignKeyList *privkeys; /* Keys to use for public-key auth */
+	m_list *privkeys; /* Keys to use for public-key auth */
 #endif
 #ifdef ENABLE_CLI_REMOTETCPFWD
-	struct TCPFwdList * remotefwds;
+	m_list * remotefwds;
 #endif
 #ifdef ENABLE_CLI_LOCALTCPFWD
-	struct TCPFwdList * localfwds;
+	m_list * localfwds;
 #endif
 #ifdef ENABLE_CLI_AGENTFWD
 	int agent_fwd;
diff --git a/session.h b/session.h
index 5a4569e..d02666d 100644
--- a/session.h
+++ b/session.h
@@ -261,7 +261,7 @@ struct clientsession {
 									  info request from the server for
 									  interactive auth.*/
 #endif
-	struct SignKeyList *lastprivkey;
+	sign_key *lastprivkey;
 
 	int retval; /* What the command exit status was - we emulate it */
 #if 0
diff --git a/signkey.c b/signkey.c
index c1ef5e2..9bc4845 100644
--- a/signkey.c
+++ b/signkey.c
@@ -40,8 +40,10 @@ sign_key * new_sign_key() {
 #ifdef DROPBEAR_RSA
 	ret->rsakey = NULL;
 #endif
+	ret->filename = NULL;
+	ret->type = DROPBEAR_SIGNKEY_NONE;
+	ret->source = SIGNKEY_SOURCE_INVALID;
 	return ret;
-
 }
 
 /* Returns "ssh-dss" or "ssh-rsa" corresponding to the type. Exits fatally
@@ -81,6 +83,9 @@ int signkey_type_from_name(const char* name, int namelen) {
 	}
 #endif
 
+	TRACE(("signkey_type_from_name unexpected key type."))
+	printhex("Key type", name, namelen);
+
 	return DROPBEAR_SIGNKEY_NONE;
 }
 
@@ -101,8 +106,11 @@ int buf_get_pub_key(buffer *buf, sign_key *key, int *type) {
 	m_free(ident);
 
 	if (*type != DROPBEAR_SIGNKEY_ANY && *type != keytype) {
+		TRACE(("buf_get_pub_key bad type - got %d, expected %d", keytype, type))
 		return DROPBEAR_FAILURE;
 	}
+	
+	TRACE(("buf_get_pub_key keytype is %d"))
 
 	*type = keytype;
 
@@ -255,6 +263,8 @@ void sign_key_free(sign_key *key) {
 	key->rsakey = NULL;
 #endif
 
+	m_free(key->filename);
+
 	m_free(key);
 	TRACE(("leave sign_key_free"))
 }
@@ -358,7 +368,6 @@ void buf_put_sign(buffer* buf, sign_key *key, int type,
 		const unsigned char *data, unsigned int len) {
 
 	buffer *sigblob;
-
 	sigblob = buf_new(MAX_PUBKEY_SIZE);
 
 #ifdef DROPBEAR_DSS
@@ -374,7 +383,6 @@ void buf_put_sign(buffer* buf, sign_key *key, int type,
 	if (sigblob->len == 0) {
 		dropbear_exit("non-matching signing type");
 	}
-
 	buf_setpos(sigblob, 0);
 	buf_putstring(buf, buf_getptr(sigblob, sigblob->len),
 			sigblob->len);
diff --git a/signkey.h b/signkey.h
index 4038b2d..9bcbfc9 100644
--- a/signkey.h
+++ b/signkey.h
@@ -29,8 +29,22 @@
 #include "dss.h"
 #include "rsa.h"
 
+
+/* Sources for signing keys */
+typedef enum {
+	SIGNKEY_SOURCE_RAW_FILE,
+	SIGNKEY_SOURCE_AGENT,
+	SIGNKEY_SOURCE_INVALID,	
+} signkey_source;
+
 struct SIGN_key {
 
+	int type; /* The type of key (dss or rsa) */
+	signkey_source source;
+	char *filename;
+	/* the buffer? for encrypted keys, so we can later get
+	 * the private key portion */
+
 #ifdef DROPBEAR_DSS
 	dss_key * dsskey;
 #endif
diff --git a/tcpfwd.h b/tcpfwd.h
index 251612e..34da314 100644
--- a/tcpfwd.h
+++ b/tcpfwd.h
@@ -25,6 +25,7 @@
 #define _TCPFWD_H
 
 #include "channel.h"
+#include "list.h"
 
 struct TCPListener {
 
@@ -43,16 +44,13 @@ struct TCPListener {
 	enum {direct, forwarded} tcp_type;
 };
 
-/* A link in a list of forwards */
-struct TCPFwdList {
-
+/* A forwarding entry */
+struct TCPFwdEntry {
 	const unsigned char* connectaddr;
 	unsigned int connectport;
 	unsigned int listenport;
 	unsigned int have_reply; /* is set to 1 after a reply has been received
 								when setting up the forwarding */
-	struct TCPFwdList * next;
-
 };
 
 /* Server */
@@ -70,5 +68,4 @@ void cli_recv_msg_request_failure();
 /* Common */
 int listen_tcpfwd(struct TCPListener* tcpinfo);
 
-
 #endif