diff --git a/ssl/s23_srvr.c b/ssl/s23_srvr.c index 49320647e7..33634efdcb 100644 --- a/ssl/s23_srvr.c +++ b/ssl/s23_srvr.c @@ -189,9 +189,10 @@ end: int ssl23_get_client_hello(SSL *s) { char buf_space[11]; /* Request this many bytes in initial read. - * We can detect SSL 3.0/TLS 1.0 Client Hellos only - * when the following is in a single record - * (not guaranteed by protocol specs): + * We can detect SSL 3.0/TLS 1.0 Client Hellos + * ('type == 3') correctly only when the following + * is in a single record, which is not guaranteed by + * the protocol specification: * Byte Content * 0 type \ * 1/2 version > record header @@ -200,7 +201,6 @@ int ssl23_get_client_hello(SSL *s) * 6-8 length > Client Hello message * 9/10 client_version / */ -/* XXX */ char *buf= &(buf_space[0]); unsigned char *p,*d,*dd; unsigned int i; @@ -338,14 +338,23 @@ int ssl23_get_client_hello(SSL *s) else if ((p[0] == SSL3_RT_HANDSHAKE) && (p[1] == SSL3_VERSION_MAJOR) && (p[5] == SSL3_MT_CLIENT_HELLO) && - (p[9] == p[1])) + ((p[3] == 0 && p[4] < 5 /* silly record length? */) + || (p[9] == p[1]))) { /* * SSLv3 or tls1 header */ - /* we must look at client_version inside the client hello: */ - v[0]=p[9]; v[1]=p[10]; + v[0]=p[1]; /* major version */ + /* We must look at client_version inside the Client Hello message + * to get the correct minor version: */ + v[1]=p[10]; + /* However if we have only a pathologically small fragment of the + * Client Hello message, we simply use the version from the + * record header -- this is incorrect but unlikely to fail in + * practice */ + if (p[3] == 0 && p[4] < 6) + v[1]=p[2]; if (v[1] >= TLS1_VERSION_MINOR) { if (!(s->options & SSL_OP_NO_TLSv1))