https://build.opensuse.org/package/view_file/network:telephony/libpt2/libpt2-openssl11.patch
by mgorse@suse.com, see also:

 - https://build.opensuse.org/request/show/518821
 - https://bugzilla.opensuse.org/show_bug.cgi?id=1055477

--- ptlib-2.10.11/src/ptclib/pssl.cxx			2013-08-14 18:20:27.000000000 -0500
+++ ptlib-2.10.11/src/ptclib/pssl.cxx.openssl11		2017-08-25 17:25:44.824287596 -0500
@@ -140,7 +140,11 @@ PFACTORY_CREATE_SINGLETON(PProcessStartu
 class PSSL_BIO
 {
   public:
+#if OPENSSL_VERSION_NUMBER >= 0x10100000
+    PSSL_BIO(const BIO_METHOD *method = BIO_s_file())
+#else
     PSSL_BIO(BIO_METHOD *method = BIO_s_file_internal())
+#endif
       { bio = BIO_new(method); }
 
     ~PSSL_BIO()
@@ -627,10 +631,18 @@ PSSLDiffieHellman::PSSLDiffieHellman(con
   if (dh == NULL)
     return;
 
+#if OPENSSL_VERSION_NUMBER >= 0x10100000l
+  DH_set0_pqg (dh, BN_bin2bn(pData, pSize, NULL), NULL, BN_bin2bn(gData, gSize, NULL));
+  const BIGNUM *p, *g;
+  DH_get0_pqg(dh, &p, NULL, &g);
+  if (p != NULL && g != NULL)
+    return;
+#else
   dh->p = BN_bin2bn(pData, pSize, NULL);
   dh->g = BN_bin2bn(gData, gSize, NULL);
   if (dh->p != NULL && dh->g != NULL)
     return;
+#endif
 
   DH_free(dh);
   dh = NULL;
@@ -805,9 +817,11 @@ void PSSLContext::Construct(Method metho
   SSL_METHOD * meth;
 
   switch (method) {
+#ifndef OPENSSL_NO_SSL3
     case SSLv3:
       meth = SSLv3_method();
       break;
+#endif
     case TLSv1:
       meth = TLSv1_method(); 
       break;
@@ -1117,7 +1131,11 @@ PBoolean PSSLChannel::RawSSLRead(void *
 //
 
 
+#if OPENSSL_VERSION_NUMBER >= 0x10100000l
+#define PSSLCHANNEL(bio)      ((PSSLChannel *)(BIO_get_data (bio)))
+#else
 #define PSSLCHANNEL(bio)      ((PSSLChannel *)(bio->ptr))
+#endif
 
 extern "C" {
 
@@ -1130,10 +1148,16 @@ typedef long (*lfptr)();
 
 static int Psock_new(BIO * bio)
 {
+#if OPENSSL_VERSION_NUMBER >= 0x10100000l
+  BIO_set_init (bio, 0);
+  BIO_set_data (bio, NULL);;    // this is really (PSSLChannel *)
+  BIO_set_flags (bio, 0);
+#else
   bio->init     = 0;
   bio->num      = 0;
   bio->ptr      = NULL;    // this is really (PSSLChannel *)
   bio->flags    = 0;
+#endif
 
   return(1);
 }
@@ -1144,13 +1168,23 @@ static int Psock_free(BIO * bio)
   if (bio == NULL)
     return 0;
 
+#if OPENSSL_VERSION_NUMBER >= 0x10100000l
+  if (BIO_get_shutdown (bio)) {
+    if (BIO_get_init (bio)) {
+#else
   if (bio->shutdown) {
     if (bio->init) {
+#endif
       PSSLCHANNEL(bio)->Shutdown(PSocket::ShutdownReadAndWrite);
       PSSLCHANNEL(bio)->Close();
     }
+#if OPENSSL_VERSION_NUMBER >= 0x10100000l
+    BIO_set_init (bio, 0);
+    BIO_set_flags (bio, 0);
+#else
     bio->init  = 0;
     bio->flags = 0;
+#endif
   }
   return 1;
 }
@@ -1160,11 +1194,19 @@ static long Psock_ctrl(BIO * bio, int cm
 {
   switch (cmd) {
     case BIO_CTRL_SET_CLOSE:
+#if OPENSSL_VERSION_NUMBER >= 0x10100000l
+      BIO_set_shutdown (bio, (int)num);
+#else
       bio->shutdown = (int)num;
+#endif
       return 1;
 
     case BIO_CTRL_GET_CLOSE:
+#if OPENSSL_VERSION_NUMBER >= 0x10100000l
+      return BIO_get_shutdown (bio);
+#else
       return bio->shutdown;
+#endif
 
     case BIO_CTRL_FLUSH:
       return 1;
@@ -1239,41 +1281,64 @@ static int Psock_puts(BIO * bio, const c
 };
 
 
-static BIO_METHOD methods_Psock =
-{
-  BIO_TYPE_SOCKET,
-  "PTLib-PSSLChannel",
-#if (OPENSSL_VERSION_NUMBER < 0x00906000)
-  (ifptr)Psock_write,
-  (ifptr)Psock_read,
-  (ifptr)Psock_puts,
-  NULL,
-  (lfptr)Psock_ctrl,
-  (ifptr)Psock_new,
-  (ifptr)Psock_free
-#else
-  Psock_write,
-  Psock_read,
-  Psock_puts,
-  NULL,
-  Psock_ctrl,
-  Psock_new,
-  Psock_free
-#endif
-};
-
 
 PBoolean PSSLChannel::OnOpen()
 {
+#if OPENSSL_VERSION_NUMBER >= 0x10100000l
+  static BIO_METHOD *methods_pSock = NULL;
+
+  if (methods_pSock == NULL) {
+    methods_pSock = BIO_meth_new (BIO_TYPE_SOCKET, "PTLib-PSSLChannel");
+    if (!methods_pSock)
+      return FALSE;
+    BIO_meth_set_write (methods_pSock, Psock_write);
+    BIO_meth_set_read (methods_pSock, Psock_read);
+    BIO_meth_set_puts (methods_pSock, Psock_puts);
+    BIO_meth_set_ctrl (methods_pSock, Psock_ctrl);
+    BIO_meth_set_create (methods_pSock, Psock_new);
+    BIO_meth_set_destroy (methods_pSock, Psock_free);
+  }
+
+  BIO * bio = BIO_new(methods_pSock);
+#else
+  static BIO_METHOD methods_Psock =
+  {
+    BIO_TYPE_SOCKET,
+    "PTLib-PSSLChannel",
+  #if (OPENSSL_VERSION_NUMBER < 0x00906000)
+    (ifptr)Psock_write,
+    (ifptr)Psock_read,
+    (ifptr)Psock_puts,
+    NULL,
+    (lfptr)Psock_ctrl,
+    (ifptr)Psock_new,
+    (ifptr)Psock_free
+  #else
+    Psock_write,
+    Psock_read,
+    Psock_puts,
+    NULL,
+    Psock_ctrl,
+    Psock_new,
+    Psock_free
+  #endif
+  };
+
   BIO * bio = BIO_new(&methods_Psock);
+#endif
   if (bio == NULL) {
     SSLerr(SSL_F_SSL_SET_FD,ERR_R_BUF_LIB);
     return PFalse;
   }
 
   // "Open" then bio
+#if OPENSSL_VERSION_NUMBER >= 0x10100000l
+  BIO_set_data (bio, this);
+  BIO_set_init (bio, 1);
+#else
   bio->ptr  = this;
   bio->init = 1;
+#endif
 
   SSL_set_bio(ssl, bio, bio);
   return PTrue;