From 0ebc965b9ca4352e407bb7cfa65ac235942117f6 Mon Sep 17 00:00:00 2001
From: "Dr. Stephen Henson" <steve@openssl.org>
Date: Sat, 25 Jan 2014 13:31:07 +0000
Subject: [PATCH] Support retries in certificate callback

---
 ssl/s3_clnt.c | 17 +++++++++++++----
 ssl/s3_srvr.c | 32 ++++++++++++++++++++++----------
 ssl/ssl3.h    |  1 +
 3 files changed, 36 insertions(+), 14 deletions(-)

diff --git a/ssl/s3_clnt.c b/ssl/s3_clnt.c
index 5f547bb114..68d3131b1e 100644
--- a/ssl/s3_clnt.c
+++ b/ssl/s3_clnt.c
@@ -3307,11 +3307,20 @@ int ssl3_send_client_certificate(SSL *s)
 	if (s->state ==	SSL3_ST_CW_CERT_A)
 		{
 		/* Let cert callback update client certificates if required */
-		if (s->cert->cert_cb
-			&& s->cert->cert_cb(s, s->cert->cert_cb_arg) <= 0)
+		if (s->cert->cert_cb)
 			{
-			ssl3_send_alert(s,SSL3_AL_FATAL,SSL_AD_INTERNAL_ERROR);
-			return 0;
+			i = s->cert->cert_cb(s, s->cert->cert_cb_arg);
+			if (i < 0)
+				{
+				s->rwstate=SSL_X509_LOOKUP;
+				return -1;
+				}
+			if (i == 0)
+				{
+				ssl3_send_alert(s,SSL3_AL_FATAL,SSL_AD_INTERNAL_ERROR);
+				return 0;
+				}
+			s->rwstate=SSL_NOTHING;
 			}
 		if (ssl3_check_client_certificate(s))
 			s->state=SSL3_ST_CW_CERT_C;
diff --git a/ssl/s3_srvr.c b/ssl/s3_srvr.c
index a3baff93f9..29459f0490 100644
--- a/ssl/s3_srvr.c
+++ b/ssl/s3_srvr.c
@@ -352,12 +352,11 @@ int ssl3_accept(SSL *s)
 		case SSL3_ST_SR_CLNT_HELLO_B:
 		case SSL3_ST_SR_CLNT_HELLO_C:
 
-			if (s->rwstate != SSL_X509_LOOKUP)
-			{
-				ret=ssl3_get_client_hello(s);
-				if (ret <= 0) goto end;
-			}
+			ret=ssl3_get_client_hello(s);
+			if (ret <= 0) goto end;
 #ifndef OPENSSL_NO_SRP
+			s->state = SSL3_ST_SR_CLNT_HELLO_D;
+		case SSL3_ST_SR_CLNT_HELLO_D:
 			{
 			int al;
 			if ((ret = ssl_check_srp_ext_ClientHello(s,&al))  < 0)
@@ -950,6 +949,9 @@ int ssl3_get_client_hello(SSL *s)
 #endif
 	STACK_OF(SSL_CIPHER) *ciphers=NULL;
 
+	if (s->state == SSL3_ST_SR_CLNT_HELLO_C)
+		goto retry_cert;
+
 	/* We do this so that we will respond with our native type.
 	 * If we are TLSv1 and we get SSLv3, we will respond with TLSv1,
 	 * This down switching should be handled by a different method.
@@ -1394,12 +1396,22 @@ int ssl3_get_client_hello(SSL *s)
 			}
 		ciphers=NULL;
 		/* Let cert callback update server certificates if required */
-		if (s->cert->cert_cb
-			&& s->cert->cert_cb(s, s->cert->cert_cb_arg) <= 0)
+		retry_cert:		
+		if (s->cert->cert_cb)
 			{
-			al=SSL_AD_INTERNAL_ERROR;
-			SSLerr(SSL_F_SSL3_GET_CLIENT_HELLO,SSL_R_CERT_CB_ERROR);
-			goto f_err;
+			int rv = s->cert->cert_cb(s, s->cert->cert_cb_arg);
+			if (rv == 0)
+				{
+				al=SSL_AD_INTERNAL_ERROR;
+				SSLerr(SSL_F_SSL3_GET_CLIENT_HELLO,SSL_R_CERT_CB_ERROR);
+				goto f_err;
+				}
+			if (rv < 0)
+				{
+				s->rwstate=SSL_X509_LOOKUP;
+				return -1;
+				}
+			s->rwstate = SSL_NOTHING;
 			}
 		c=ssl3_choose_cipher(s,s->session->ciphers,
 				     SSL_get_ciphers(s));
diff --git a/ssl/ssl3.h b/ssl/ssl3.h
index c94b3a4290..8fe6949f6d 100644
--- a/ssl/ssl3.h
+++ b/ssl/ssl3.h
@@ -685,6 +685,7 @@ typedef struct ssl3_state_st
 #define SSL3_ST_SR_CLNT_HELLO_A		(0x110|SSL_ST_ACCEPT)
 #define SSL3_ST_SR_CLNT_HELLO_B		(0x111|SSL_ST_ACCEPT)
 #define SSL3_ST_SR_CLNT_HELLO_C		(0x112|SSL_ST_ACCEPT)
+#define SSL3_ST_SR_CLNT_HELLO_D		(0x115|SSL_ST_ACCEPT)
 #ifndef OPENSSL_NO_TLSEXT
 #define SSL3_ST_SR_SUPPLEMENTAL_DATA_A		(0x212|SSL_ST_ACCEPT)
 #define SSL3_ST_SR_SUPPLEMENTAL_DATA_B		(0x213|SSL_ST_ACCEPT)
-- 
2.34.1