Improve dtls compatibility with old DTLS servers (such as CISCO AnyConnect).
Additional backported DTLS fixes.
diff -up openssl-0.9.8g/ssl/d1_clnt.c.dtls-compat openssl-0.9.8g/ssl/d1_clnt.c
--- openssl-0.9.8g/ssl/d1_clnt.c.dtls-compat	2007-09-30 21:36:32.000000000 +0200
+++ openssl-0.9.8g/ssl/d1_clnt.c	2009-04-21 14:17:41.000000000 +0200
@@ -130,7 +130,7 @@ static int dtls1_get_hello_verify(SSL *s
 
 static SSL_METHOD *dtls1_get_client_method(int ver)
 	{
-	if (ver == DTLS1_VERSION)
+	if (ver == DTLS1_VERSION || ver == DTLS1_BAD_VER)
 		return(DTLSv1_client_method());
 	else
 		return(NULL);
@@ -181,7 +181,8 @@ int dtls1_connect(SSL *s)
 			s->server=0;
 			if (cb != NULL) cb(s,SSL_CB_HANDSHAKE_START,1);
 
-			if ((s->version & 0xff00 ) != (DTLS1_VERSION & 0xff00))
+			if ((s->version & 0xff00 ) != (DTLS1_VERSION & 0xff00) &&
+			    (s->version & 0xff00 ) != (DTLS1_BAD_VER & 0xff00))
 				{
 				SSLerr(SSL_F_DTLS1_CONNECT, ERR_R_INTERNAL_ERROR);
 				ret = -1;
diff -up openssl-0.9.8g/ssl/d1_lib.c.dtls-compat openssl-0.9.8g/ssl/d1_lib.c
--- openssl-0.9.8g/ssl/d1_lib.c.dtls-compat	2007-10-05 23:05:27.000000000 +0200
+++ openssl-0.9.8g/ssl/d1_lib.c	2009-04-21 14:19:07.000000000 +0200
@@ -106,6 +106,7 @@ int dtls1_new(SSL *s)
 	pq_64bit_init(&(d1->bitmap.map));
 	pq_64bit_init(&(d1->bitmap.max_seq_num));
 	
+	d1->next_bitmap.length = d1->bitmap.length;
 	pq_64bit_init(&(d1->next_bitmap.map));
 	pq_64bit_init(&(d1->next_bitmap.max_seq_num));
 
@@ -186,7 +187,10 @@ void dtls1_free(SSL *s)
 void dtls1_clear(SSL *s)
 	{
 	ssl3_clear(s);
-	s->version=DTLS1_VERSION;
+	if (s->options & SSL_OP_CISCO_ANYCONNECT)
+		s->version=DTLS1_BAD_VER;
+	else
+		s->version=DTLS1_VERSION;
 	}
 
 /*
diff -up openssl-0.9.8g/ssl/d1_pkt.c.dtls-compat openssl-0.9.8g/ssl/d1_pkt.c
--- openssl-0.9.8g/ssl/d1_pkt.c.dtls-compat	2007-10-19 09:39:53.000000000 +0200
+++ openssl-0.9.8g/ssl/d1_pkt.c	2009-04-21 14:36:15.000000000 +0200
@@ -597,6 +597,7 @@ again:
 	/* check whether this is a repeat, or aged record */
 	if ( ! dtls1_record_replay_check(s, bitmap, &(rr->seq_num)))
 		{
+		rr->length = 0;
 		s->packet_length=0; /* dump this record */
 		goto again;     /* get another record */
 		}
@@ -978,15 +979,17 @@ start:
 	if (rr->type == SSL3_RT_CHANGE_CIPHER_SPEC)
 		{
 		struct ccs_header_st ccs_hdr;
+		int ccs_hdr_len = DTLS1_CCS_HEADER_LENGTH;
 
 		dtls1_get_ccs_header(rr->data, &ccs_hdr);
 
 		/* 'Change Cipher Spec' is just a single byte, so we know
 		 * exactly what the record payload has to look like */
 		/* XDTLS: check that epoch is consistent */
-		if (	(s->client_version == DTLS1_BAD_VER && rr->length != 3) ||
-			(s->client_version != DTLS1_BAD_VER && rr->length != DTLS1_CCS_HEADER_LENGTH) || 
-			(rr->off != 0) || (rr->data[0] != SSL3_MT_CCS))
+		if (s->client_version == DTLS1_BAD_VER || s->version == DTLS1_BAD_VER)
+			ccs_hdr_len = 3;
+
+		if ((rr->length != ccs_hdr_len) || (rr->off != 0) || (rr->data[0] != SSL3_MT_CCS))
 			{
 			i=SSL_AD_ILLEGAL_PARAMETER;
 			SSLerr(SSL_F_DTLS1_READ_BYTES,SSL_R_BAD_CHANGE_CIPHER_SPEC);
@@ -1251,7 +1254,7 @@ int dtls1_write_bytes(SSL *s, int type, 
 	else 
 		s->s3->wnum += i;
 
-	return tot + i;
+	return i;
 	}
 
 int do_dtls1_write(SSL *s, int type, const unsigned char *buf, unsigned int len, int create_empty_fragment)
@@ -1302,7 +1305,7 @@ int do_dtls1_write(SSL *s, int type, con
 #if 0
 	/* 'create_empty_fragment' is true only when this function calls itself */
 	if (!clear && !create_empty_fragment && !s->s3->empty_fragment_done
-		&& SSL_version(s) != DTLS1_VERSION)
+	    && SSL_version(s) != DTLS1_VERSION && SSL_version(s) != DTLS1_BAD_VER)
 		{
 		/* countermeasure against known-IV weakness in CBC ciphersuites
 		 * (see http://www.openssl.org/~bodo/tls-cbc.txt) 
diff -up openssl-0.9.8g/ssl/s3_clnt.c.dtls-compat openssl-0.9.8g/ssl/s3_clnt.c
--- openssl-0.9.8g/ssl/s3_clnt.c.dtls-compat	2009-01-07 16:11:32.000000000 +0100
+++ openssl-0.9.8g/ssl/s3_clnt.c	2009-04-21 14:17:41.000000000 +0200
@@ -676,7 +676,7 @@ int ssl3_get_server_hello(SSL *s)
 
 	if (!ok) return((int)n);
 
-	if ( SSL_version(s) == DTLS1_VERSION)
+	if ( SSL_version(s) == DTLS1_VERSION || SSL_version(s) == DTLS1_BAD_VER)
 		{
 		if ( s->s3->tmp.message_type == DTLS1_MT_HELLO_VERIFY_REQUEST)
 			{
diff -up openssl-0.9.8g/ssl/s3_pkt.c.dtls-compat openssl-0.9.8g/ssl/s3_pkt.c
--- openssl-0.9.8g/ssl/s3_pkt.c.dtls-compat	2006-11-29 15:45:14.000000000 +0100
+++ openssl-0.9.8g/ssl/s3_pkt.c	2009-04-21 14:39:07.000000000 +0200
@@ -754,7 +754,16 @@ int ssl3_write_pending(SSL *s, int type,
 			return(s->s3->wpend_ret);
 			}
 		else if (i <= 0)
+			{
+			if (s->version == DTLS1_VERSION ||
+			    s->version == DTLS1_BAD_VER)
+				{
+				/* For DTLS, just drop it. That's kind of the whole
+				   point in using a datagram service */
+				s->s3->wbuf.left = 0;
+				}
 			return(i);
+			}
 		s->s3->wbuf.offset+=i;
 		s->s3->wbuf.left-=i;
 		}
diff -up openssl-0.9.8g/ssl/ssl_err.c.dtls-compat openssl-0.9.8g/ssl/ssl_err.c
--- openssl-0.9.8g/ssl/ssl_err.c.dtls-compat	2007-10-11 16:36:59.000000000 +0200
+++ openssl-0.9.8g/ssl/ssl_err.c	2009-04-21 14:55:47.000000000 +0200
@@ -138,6 +138,7 @@ static ERR_STRING_DATA SSL_str_functs[]=
 {ERR_FUNC(SSL_F_SSL3_CONNECT),	"SSL3_CONNECT"},
 {ERR_FUNC(SSL_F_SSL3_CTRL),	"SSL3_CTRL"},
 {ERR_FUNC(SSL_F_SSL3_CTX_CTRL),	"SSL3_CTX_CTRL"},
+{ERR_FUNC(SSL_F_SSL3_DO_CHANGE_CIPHER_SPEC),	"SSL3_DO_CHANGE_CIPHER_SPEC"},
 {ERR_FUNC(SSL_F_SSL3_ENC),	"SSL3_ENC"},
 {ERR_FUNC(SSL_F_SSL3_GENERATE_KEY_BLOCK),	"SSL3_GENERATE_KEY_BLOCK"},
 {ERR_FUNC(SSL_F_SSL3_GET_CERTIFICATE_REQUEST),	"SSL3_GET_CERTIFICATE_REQUEST"},
diff -up openssl-0.9.8g/ssl/ssl.h.dtls-compat openssl-0.9.8g/ssl/ssl.h
--- openssl-0.9.8g/ssl/ssl.h.dtls-compat	2009-01-07 16:09:11.000000000 +0100
+++ openssl-0.9.8g/ssl/ssl.h	2009-04-21 14:55:08.000000000 +0200
@@ -511,6 +511,8 @@ typedef struct ssl_session_st
 #define SSL_OP_COOKIE_EXCHANGE              0x00002000L
 /* Don't use RFC4507 ticket extension */
 #define SSL_OP_NO_TICKET	            0x00004000L
+/* Use Cisco's "speshul" version of DTLS_BAD_VER (as client)  */
+#define SSL_OP_CISCO_ANYCONNECT		    0x00008000L
 
 /* As server, disallow session resumption on renegotiation */
 #define SSL_OP_NO_SESSION_RESUMPTION_ON_RENEGOTIATION	0x00010000L
@@ -1658,6 +1660,7 @@ void ERR_load_SSL_strings(void);
 #define SSL_F_SSL3_CONNECT				 132
 #define SSL_F_SSL3_CTRL					 213
 #define SSL_F_SSL3_CTX_CTRL				 133
+#define SSL_F_SSL3_DO_CHANGE_CIPHER_SPEC		 279
 #define SSL_F_SSL3_ENC					 134
 #define SSL_F_SSL3_GENERATE_KEY_BLOCK			 238
 #define SSL_F_SSL3_GET_CERTIFICATE_REQUEST		 135
diff -up openssl-0.9.8g/ssl/ssl_lib.c.dtls-compat openssl-0.9.8g/ssl/ssl_lib.c
--- openssl-0.9.8g/ssl/ssl_lib.c.dtls-compat	2007-09-19 14:16:21.000000000 +0200
+++ openssl-0.9.8g/ssl/ssl_lib.c	2009-04-21 14:17:41.000000000 +0200
@@ -976,7 +976,8 @@ long SSL_ctrl(SSL *s,int cmd,long larg,v
 		s->max_cert_list=larg;
 		return(l);
 	case SSL_CTRL_SET_MTU:
-		if (SSL_version(s) == DTLS1_VERSION)
+		if (SSL_version(s) == DTLS1_VERSION ||
+		    SSL_version(s) == DTLS1_BAD_VER)
 			{
 			s->d1->mtu = larg;
 			return larg;
diff -up openssl-0.9.8g/ssl/ssl_sess.c.dtls-compat openssl-0.9.8g/ssl/ssl_sess.c
--- openssl-0.9.8g/ssl/ssl_sess.c.dtls-compat	2007-10-19 09:36:34.000000000 +0200
+++ openssl-0.9.8g/ssl/ssl_sess.c	2009-04-21 14:17:41.000000000 +0200
@@ -208,6 +208,11 @@ int ssl_get_new_session(SSL *s, int sess
 			ss->ssl_version=TLS1_VERSION;
 			ss->session_id_length=SSL3_SSL_SESSION_ID_LENGTH;
 			}
+		else if (s->version == DTLS1_BAD_VER)
+			{
+			ss->ssl_version=DTLS1_BAD_VER;
+			ss->session_id_length=SSL3_SSL_SESSION_ID_LENGTH;
+			}
 		else if (s->version == DTLS1_VERSION)
 			{
 			ss->ssl_version=DTLS1_VERSION;
diff -up openssl-0.9.8g/ssl/t1_enc.c.dtls-compat openssl-0.9.8g/ssl/t1_enc.c
--- openssl-0.9.8g/ssl/t1_enc.c.dtls-compat	2007-10-09 21:22:01.000000000 +0200
+++ openssl-0.9.8g/ssl/t1_enc.c	2009-04-21 14:17:41.000000000 +0200
@@ -755,10 +755,10 @@ int tls1_mac(SSL *ssl, unsigned char *md
 	HMAC_CTX_init(&hmac);
 	HMAC_Init_ex(&hmac,mac_sec,EVP_MD_size(hash),hash,NULL);
 
-	if (ssl->version == DTLS1_VERSION && ssl->client_version != DTLS1_BAD_VER)
+	if (ssl->version == DTLS1_BAD_VER ||
+	    (ssl->version == DTLS1_VERSION && ssl->client_version != DTLS1_BAD_VER))
 		{
 		unsigned char dtlsseq[8],*p=dtlsseq;
-
 		s2n(send?ssl->d1->w_epoch:ssl->d1->r_epoch, p);
 		memcpy (p,&seq[2],6);
 
@@ -783,7 +783,7 @@ printf("rec=");
 {unsigned int z; for (z=0; z<rec->length; z++) printf("%02X ",buf[z]); printf("\n"); }
 #endif
 
-	if ( SSL_version(ssl) != DTLS1_VERSION)
+	if ( SSL_version(ssl) != DTLS1_VERSION && SSL_version(ssl) != DTLS1_BAD_VER)
 		{
 		for (i=7; i>=0; i--)
 			{