Add new ctrl to retrieve client certificate types, print out
details in s_client.

Also add ctrl to set client certificate types. If not used sensible values
will be included based on supported signature algorithms: for example if
we don't include any DSA signing algorithms the DSA certificate type is
omitted.

Fix restriction in old code where certificate types would be truncated
if it exceeded TLS_CT_NUMBER.

ssl/s3_lib.c

diff --git a/ssl/s3_lib.c b/ssl/s3_lib.c
index 2c6e1ad..457a5c7 100644
--- a/ssl/s3_lib.c
+++ b/ssl/s3_lib.c
@@ -3089,6 +3089,8 @@
 	}
 #endif
 
+static int ssl3_set_req_cert_type(CERT *c, const unsigned char *p, size_t len);
+
 long ssl3_ctrl(SSL *s, int cmd, long larg, void *parg)
 	{
 	int ret=0;
@@ -3426,6 +3428,27 @@
 	case SSL_CTRL_SET_CLIENT_SIGALGS_LIST:
 		return tls1_set_sigalgs_list(s->cert, parg, 1);
 
+	case SSL_CTRL_GET_CLIENT_CERT_TYPES:
+		{
+		const unsigned char **pctype = parg;
+		if (s->server || !s->s3->tmp.cert_req)
+			return 0;
+		if (s->cert->ctypes)
+			{
+			if (pctype)
+				*pctype = s->cert->ctypes;
+			return (int)s->cert->ctype_num;
+			}
+		if (pctype)
+			*pctype = (unsigned char *)s->s3->tmp.ctype;
+		return s->s3->tmp.ctype_num;
+		}
+
+	case SSL_CTRL_SET_CLIENT_CERT_TYPES:
+		if (!s->server)
+			return 0;
+		return ssl3_set_req_cert_type(s->cert, parg, larg);
+
 	default:
 		break;
 		}
@@ -3720,6 +3743,9 @@
 	case SSL_CTRL_SET_CLIENT_SIGALGS_LIST:
 		return tls1_set_sigalgs_list(ctx->cert, parg, 1);
 
+	case SSL_CTRL_SET_CLIENT_CERT_TYPES:
+		return ssl3_set_req_cert_type(ctx->cert, parg, larg);
+
 	case SSL_CTRL_SET_TLSEXT_AUTHZ_SERVER_AUDIT_PROOF_CB_ARG:
 		ctx->tlsext_authz_server_audit_proof_cb_arg = parg;
 		break;
@@ -4014,8 +4040,61 @@
 int ssl3_get_req_cert_type(SSL *s, unsigned char *p)
 	{
 	int ret=0;
+	const unsigned char *sig;
+	size_t siglen;
+	int have_rsa_sign = 0, have_dsa_sign = 0, have_ecdsa_sign = 0;
+	int nostrict = 1;
 	unsigned long alg_k;
 
+	/* If we have custom certificate types set, use them */
+	if (s->cert->ctypes)
+		{
+		memcpy(p, s->cert->ctypes, s->cert->ctype_num);
+		return (int)s->cert->ctype_num;
+		}
+	/* Else see if we have any signature algorithms configured */
+	if (s->cert->client_sigalgs)
+		{
+		sig = s->cert->client_sigalgs;
+		siglen = s->cert->client_sigalgslen;
+		}
+	else
+		{
+		sig = s->cert->conf_sigalgs;
+		siglen = s->cert->conf_sigalgslen;
+		}
+	/* If we have sigalgs work out if we can sign with RSA, DSA, ECDSA */
+	if (sig)
+		{
+		size_t i;
+		if (s->cert->cert_flags & SSL_CERT_FLAG_TLS_STRICT)
+			nostrict = 0;
+		for (i = 0; i < siglen; i+=2, sig+=2)
+			{
+			switch(sig[1])
+				{
+			case TLSEXT_signature_rsa:
+				have_rsa_sign = 1;
+				break;
+
+			case TLSEXT_signature_dsa:
+				have_dsa_sign = 1;
+				break;
+
+			case TLSEXT_signature_ecdsa:
+				have_ecdsa_sign = 1;
+				break;
+				}
+			}
+		}
+	/* Otherwise allow anything */
+	else
+		{
+		have_rsa_sign = 1;
+		have_dsa_sign = 1;
+		have_ecdsa_sign = 1;
+		}
+
 	alg_k = s->s3->tmp.new_cipher->algorithm_mkey;
 
 #ifndef OPENSSL_NO_GOST
@@ -4034,10 +4113,15 @@
 	if (alg_k & (SSL_kDHr|SSL_kEDH))
 		{
 #  ifndef OPENSSL_NO_RSA
-		p[ret++]=SSL3_CT_RSA_FIXED_DH;
+		/* Since this refers to a certificate signed with an RSA
+		 * algorithm, only check for rsa signing in strict mode.
+		 */
+		if (nostrict || have_rsa_sign)
+			p[ret++]=SSL3_CT_RSA_FIXED_DH;
 #  endif
 #  ifndef OPENSSL_NO_DSA
-		p[ret++]=SSL3_CT_DSS_FIXED_DH;
+		if (nostrict || have_dsa_sign)
+			p[ret++]=SSL3_CT_DSS_FIXED_DH;
 #  endif
 		}
 	if ((s->version == SSL3_VERSION) &&
@@ -4052,16 +4136,20 @@
 		}
 #endif /* !OPENSSL_NO_DH */
 #ifndef OPENSSL_NO_RSA
-	p[ret++]=SSL3_CT_RSA_SIGN;
+	if (have_rsa_sign)
+		p[ret++]=SSL3_CT_RSA_SIGN;
 #endif
 #ifndef OPENSSL_NO_DSA
-	p[ret++]=SSL3_CT_DSS_SIGN;
+	if (have_dsa_sign)
+		p[ret++]=SSL3_CT_DSS_SIGN;
 #endif
 #ifndef OPENSSL_NO_ECDH
 	if ((alg_k & (SSL_kECDHr|SSL_kECDHe)) && (s->version >= TLS1_VERSION))
 		{
-		p[ret++]=TLS_CT_RSA_FIXED_ECDH;
-		p[ret++]=TLS_CT_ECDSA_FIXED_ECDH;
+		if (nostrict || have_rsa_sign)
+			p[ret++]=TLS_CT_RSA_FIXED_ECDH;
+		if (nostrict || have_ecdsa_sign)
+			p[ret++]=TLS_CT_ECDSA_FIXED_ECDH;
 		}
 #endif
 
@@ -4071,12 +4159,32 @@
 	 */
 	if (s->version >= TLS1_VERSION)
 		{
-		p[ret++]=TLS_CT_ECDSA_SIGN;
+		if (have_ecdsa_sign)
+			p[ret++]=TLS_CT_ECDSA_SIGN;
 		}
 #endif	
 	return(ret);
 	}
 
+static int ssl3_set_req_cert_type(CERT *c, const unsigned char *p, size_t len)
+	{
+	if (c->ctypes)
+		{
+		OPENSSL_free(c->ctypes);
+		c->ctypes = NULL;
+		}
+	if (!p || !len)
+		return 1;
+	if (len > 0xff)
+		return 0;
+	c->ctypes = OPENSSL_malloc(len);
+	if (!c->ctypes)
+		return 0;
+	memcpy(c->ctypes, p, len);
+	c->ctype_num = len;
+	return 1;
+	}
+
 int ssl3_shutdown(SSL *s)
 	{
 	int ret;