diff --git a/Modules/_hashopenssl.c b/Modules/_hashopenssl.c
index cb8460ab2f..2c245262f3 100644
--- a/Modules/_hashopenssl.c
+++ b/Modules/_hashopenssl.c
@@ -45,10 +45,12 @@
 
 #define MUNCH_SIZE INT_MAX
 
+#ifndef LIBRESSL_VERSION_NUMBER
 #define PY_OPENSSL_HAS_SCRYPT 1
 #define PY_OPENSSL_HAS_SHA3 1
 #define PY_OPENSSL_HAS_SHAKE 1
 #define PY_OPENSSL_HAS_BLAKE2 1
+#endif
 
 #if OPENSSL_VERSION_NUMBER >= 0x30000000L
 #define PY_EVP_MD EVP_MD
@@ -1884,6 +1886,7 @@ hashlib_md_meth_names(PyObject *module)
     return 0;
 }
 
+#ifndef LIBRESSL_VERSION_NUMBER
 /*[clinic input]
 _hashlib.get_fips_mode -> int
 
@@ -1921,6 +1924,7 @@ _hashlib_get_fips_mode_impl(PyObject *module)
     return result;
 #endif
 }
+#endif
 
 
 static int
diff --git a/Modules/_ssl.c b/Modules/_ssl.c
index 6c63301b2a..d8a70d5511 100644
--- a/Modules/_ssl.c
+++ b/Modules/_ssl.c
@@ -291,8 +291,10 @@ typedef struct {
     int post_handshake_auth;
 #endif
     PyObject *msg_cb;
+#ifndef LIBRESSL_VERSION_NUMBER
     PyObject *keylog_filename;
     BIO *keylog_bio;
+#endif
     /* Cached module state, also used in SSLSocket and SSLSession code. */
     _sslmodulestate *state;
 } PySSLContext;
@@ -1829,6 +1831,7 @@ _ssl__SSLSocket_getpeercert_impl(PySSLSocket *self, int binary_mode)
     return result;
 }
 
+#ifndef LIBRESSL_VERSION_NUMBER
 /*[clinic input]
 _ssl._SSLSocket.get_verified_chain
 
@@ -1892,6 +1895,7 @@ _ssl__SSLSocket_get_unverified_chain_impl(PySSLSocket *self)
     }
     return retval;
 }
+#endif
 
 static PyObject *
 cipher_to_tuple(const SSL_CIPHER *cipher)
@@ -2298,8 +2302,7 @@ static PyObject *
 _ssl__SSLSocket_write_impl(PySSLSocket *self, Py_buffer *b)
 /*[clinic end generated code: output=aa7a6be5527358d8 input=77262d994fe5100a]*/
 {
-    size_t count = 0;
-    int retval;
+    int len;
     int sockstate;
     _PySSLError err;
     int nonblocking;
@@ -2317,6 +2320,12 @@ _ssl__SSLSocket_write_impl(PySSLSocket *self, Py_buffer *b)
         Py_INCREF(sock);
     }
 
+    if (b->len > INT_MAX) {
+        PyErr_Format(PyExc_OverflowError,
+                     "string longer than %d bytes", INT_MAX);
+        goto error;
+    }
+
     if (sock != NULL) {
         /* just in case the blocking state of the socket has been changed */
         nonblocking = (sock->sock_timeout >= 0);
@@ -2346,8 +2355,8 @@ _ssl__SSLSocket_write_impl(PySSLSocket *self, Py_buffer *b)
 
     do {
         PySSL_BEGIN_ALLOW_THREADS
-        retval = SSL_write_ex(self->ssl, b->buf, (size_t)b->len, &count);
-        err = _PySSL_errno(retval == 0, self->ssl, retval);
+        len = SSL_write(self->ssl, b->buf, (int)b->len);
+        err = _PySSL_errno(len <= 0, self->ssl, len);
         PySSL_END_ALLOW_THREADS
         self->err = err;
 
@@ -2380,11 +2389,11 @@ _ssl__SSLSocket_write_impl(PySSLSocket *self, Py_buffer *b)
              err.ssl == SSL_ERROR_WANT_WRITE);
 
     Py_XDECREF(sock);
-    if (retval == 0)
-        return PySSL_SetError(self, retval, __FILE__, __LINE__);
+    if (len <= 0)
+        return PySSL_SetError(self, len, __FILE__, __LINE__);
     if (PySSL_ChainExceptions(self) < 0)
         return NULL;
-    return PyLong_FromSize_t(count);
+    return PyLong_FromLong(len);
 error:
     Py_XDECREF(sock);
     PySSL_ChainExceptions(self);
@@ -2418,7 +2427,7 @@ _ssl__SSLSocket_pending_impl(PySSLSocket *self)
 
 /*[clinic input]
 _ssl._SSLSocket.read
-    size as len: Py_ssize_t
+    size as len: int
     [
     buffer: Py_buffer(accept={rwbuffer})
     ]
@@ -2428,14 +2437,13 @@ Read up to size bytes from the SSL socket.
 [clinic start generated code]*/
 
 static PyObject *
-_ssl__SSLSocket_read_impl(PySSLSocket *self, Py_ssize_t len,
-                          int group_right_1, Py_buffer *buffer)
-/*[clinic end generated code: output=49b16e6406023734 input=ec48bf622be1c4a1]*/
+_ssl__SSLSocket_read_impl(PySSLSocket *self, int len, int group_right_1,
+                          Py_buffer *buffer)
+/*[clinic end generated code: output=00097776cec2a0af input=ff157eb918d0905b]*/
 {
     PyObject *dest = NULL;
     char *mem;
-    size_t count = 0;
-    int retval;
+    int count;
     int sockstate;
     _PySSLError err;
     int nonblocking;
@@ -2498,8 +2506,8 @@ _ssl__SSLSocket_read_impl(PySSLSocket *self, Py_ssize_t len,
 
     do {
         PySSL_BEGIN_ALLOW_THREADS
-        retval = SSL_read_ex(self->ssl, mem, (size_t)len, &count);
-        err = _PySSL_errno(retval == 0, self->ssl, retval);
+        count = SSL_read(self->ssl, mem, len);
+        err = _PySSL_errno(count <= 0, self->ssl, count);
         PySSL_END_ALLOW_THREADS
         self->err = err;
 
@@ -2532,8 +2540,8 @@ _ssl__SSLSocket_read_impl(PySSLSocket *self, Py_ssize_t len,
     } while (err.ssl == SSL_ERROR_WANT_READ ||
              err.ssl == SSL_ERROR_WANT_WRITE);
 
-    if (retval == 0) {
-        PySSL_SetError(self, retval, __FILE__, __LINE__);
+    if (count <= 0) {
+        PySSL_SetError(self, count, __FILE__, __LINE__);
         goto error;
     }
     if (self->exc_type != NULL)
@@ -2546,7 +2554,7 @@ _ssl__SSLSocket_read_impl(PySSLSocket *self, Py_ssize_t len,
         return dest;
     }
     else {
-        return PyLong_FromSize_t(count);
+        return PyLong_FromLong(count);
     }
 
 error:
@@ -3062,8 +3070,10 @@ _ssl__SSLContext_impl(PyTypeObject *type, int proto_version)
     self->hostflags = X509_CHECK_FLAG_NO_PARTIAL_WILDCARDS;
     self->protocol = proto_version;
     self->msg_cb = NULL;
+#ifndef LIBRESSL_VERSION_NUMBER
     self->keylog_filename = NULL;
     self->keylog_bio = NULL;
+#endif
     self->alpn_protocols = NULL;
     self->set_sni_cb = NULL;
     self->state = get_ssl_state(module);
@@ -3187,6 +3197,7 @@ context_clear(PySSLContext *self)
 {
     Py_CLEAR(self->set_sni_cb);
     Py_CLEAR(self->msg_cb);
+#ifndef LIBRESSL_VERSION_NUMBER
     Py_CLEAR(self->keylog_filename);
     if (self->keylog_bio != NULL) {
         PySSL_BEGIN_ALLOW_THREADS
@@ -3194,6 +3205,7 @@ context_clear(PySSLContext *self)
         PySSL_END_ALLOW_THREADS
         self->keylog_bio = NULL;
     }
+#endif
     return 0;
 }
 
@@ -3535,7 +3547,7 @@ set_maximum_version(PySSLContext *self, PyObject *arg, void *c)
     return set_min_max_proto_version(self, arg, 1);
 }
 
-#ifdef TLS1_3_VERSION
+#if defined(TLS1_3_VERSION) && !defined(LIBRESSL_VERSION_NUMBER)
 static PyObject *
 get_num_tickets(PySSLContext *self, void *c)
 {
@@ -3568,12 +3580,14 @@ PyDoc_STRVAR(PySSLContext_num_tickets_doc,
 "Control the number of TLSv1.3 session tickets");
 #endif /* TLS1_3_VERSION */
 
+#ifndef LIBRESSL_VERSION_NUMBER
 static PyObject *
 get_security_level(PySSLContext *self, void *c)
 {
     return PyLong_FromLong(SSL_CTX_get_security_level(self->ctx));
 }
 PyDoc_STRVAR(PySSLContext_security_level_doc, "The current security level");
+#endif
 
 static PyObject *
 get_options(PySSLContext *self, void *c)
@@ -4603,13 +4617,15 @@ static PyGetSetDef context_getsetlist[] = {
                         (setter) set_minimum_version, NULL},
     {"maximum_version", (getter) get_maximum_version,
                         (setter) set_maximum_version, NULL},
+#ifndef LIBRESSL_VERSION_NUMBER
     {"keylog_filename", (getter) _PySSLContext_get_keylog_filename,
                         (setter) _PySSLContext_set_keylog_filename, NULL},
+#endif
     {"_msg_callback", (getter) _PySSLContext_get_msg_callback,
                       (setter) _PySSLContext_set_msg_callback, NULL},
     {"sni_callback", (getter) get_sni_callback,
                      (setter) set_sni_callback, PySSLContext_sni_callback_doc},
-#ifdef TLS1_3_VERSION
+#if defined(TLS1_3_VERSION) && !defined(LIBRESSL_VERSION_NUMBER)
     {"num_tickets", (getter) get_num_tickets,
                     (setter) set_num_tickets, PySSLContext_num_tickets_doc},
 #endif
@@ -4628,8 +4644,10 @@ static PyGetSetDef context_getsetlist[] = {
                      (setter) set_verify_flags, NULL},
     {"verify_mode", (getter) get_verify_mode,
                     (setter) set_verify_mode, NULL},
+#ifndef LIBRESSL_VERSION_NUMBER
     {"security_level", (getter) get_security_level,
                        NULL, PySSLContext_security_level_doc},
+#endif
     {NULL},            /* sentinel */
 };
 
diff --git a/Modules/_ssl/debughelpers.c b/Modules/_ssl/debughelpers.c
index 03c125eb44..d992c5bc02 100644
--- a/Modules/_ssl/debughelpers.c
+++ b/Modules/_ssl/debughelpers.c
@@ -114,6 +114,8 @@ _PySSLContext_set_msg_callback(PySSLContext *self, PyObject *arg, void *c) {
     return 0;
 }
 
+#ifndef LIBRESSL_VERSION_NUMBER
+
 static void
 _PySSL_keylog_callback(const SSL *ssl, const char *line)
 {
@@ -217,3 +219,5 @@ _PySSLContext_set_keylog_filename(PySSLContext *self, PyObject *arg, void *c) {
     SSL_CTX_set_keylog_callback(self->ctx, _PySSL_keylog_callback);
     return 0;
 }
+
+#endif
diff --git a/Modules/clinic/_hashopenssl.c.h b/Modules/clinic/_hashopenssl.c.h
index de01489e6a..c686eddea8 100644
--- a/Modules/clinic/_hashopenssl.c.h
+++ b/Modules/clinic/_hashopenssl.c.h
@@ -1275,6 +1275,8 @@ _hashlib_HMAC_hexdigest(HMACobject *self, PyObject *Py_UNUSED(ignored))
     return _hashlib_HMAC_hexdigest_impl(self);
 }
 
+#if !defined(LIBRESSL_VERSION_NUMBER)
+
 PyDoc_STRVAR(_hashlib_get_fips_mode__doc__,
 "get_fips_mode($module, /)\n"
 "--\n"
@@ -1310,6 +1312,8 @@ _hashlib_get_fips_mode(PyObject *module, PyObject *Py_UNUSED(ignored))
     return return_value;
 }
 
+#endif /* !defined(LIBRESSL_VERSION_NUMBER) */
+
 PyDoc_STRVAR(_hashlib_compare_digest__doc__,
 "compare_digest($module, a, b, /)\n"
 "--\n"
@@ -1385,4 +1389,8 @@ _hashlib_compare_digest(PyObject *module, PyObject *const *args, Py_ssize_t narg
 #ifndef _HASHLIB_SCRYPT_METHODDEF
     #define _HASHLIB_SCRYPT_METHODDEF
 #endif /* !defined(_HASHLIB_SCRYPT_METHODDEF) */
-/*[clinic end generated code: output=162369cb9d43f1cc input=a9049054013a1b77]*/
+
+#ifndef _HASHLIB_GET_FIPS_MODE_METHODDEF
+    #define _HASHLIB_GET_FIPS_MODE_METHODDEF
+#endif /* !defined(_HASHLIB_GET_FIPS_MODE_METHODDEF) */
+/*[clinic end generated code: output=a110f274fb33395d input=a9049054013a1b77]*/
diff --git a/Modules/clinic/_ssl.c.h b/Modules/clinic/_ssl.c.h
index b59b129af8..f6bcd09e03 100644
--- a/Modules/clinic/_ssl.c.h
+++ b/Modules/clinic/_ssl.c.h
@@ -88,6 +88,8 @@ _ssl__SSLSocket_getpeercert(PySSLSocket *self, PyObject *const *args, Py_ssize_t
     return return_value;
 }
 
+#if !defined(LIBRESSL_VERSION_NUMBER)
+
 PyDoc_STRVAR(_ssl__SSLSocket_get_verified_chain__doc__,
 "get_verified_chain($self, /)\n"
 "--\n"
@@ -105,6 +107,10 @@ _ssl__SSLSocket_get_verified_chain(PySSLSocket *self, PyObject *Py_UNUSED(ignore
     return _ssl__SSLSocket_get_verified_chain_impl(self);
 }
 
+#endif /* !defined(LIBRESSL_VERSION_NUMBER) */
+
+#if !defined(LIBRESSL_VERSION_NUMBER)
+
 PyDoc_STRVAR(_ssl__SSLSocket_get_unverified_chain__doc__,
 "get_unverified_chain($self, /)\n"
 "--\n"
@@ -122,6 +128,8 @@ _ssl__SSLSocket_get_unverified_chain(PySSLSocket *self, PyObject *Py_UNUSED(igno
     return _ssl__SSLSocket_get_unverified_chain_impl(self);
 }
 
+#endif /* !defined(LIBRESSL_VERSION_NUMBER) */
+
 PyDoc_STRVAR(_ssl__SSLSocket_shared_ciphers__doc__,
 "shared_ciphers($self, /)\n"
 "--\n"
@@ -271,25 +279,25 @@ PyDoc_STRVAR(_ssl__SSLSocket_read__doc__,
     {"read", (PyCFunction)_ssl__SSLSocket_read, METH_VARARGS, _ssl__SSLSocket_read__doc__},
 
 static PyObject *
-_ssl__SSLSocket_read_impl(PySSLSocket *self, Py_ssize_t len,
-                          int group_right_1, Py_buffer *buffer);
+_ssl__SSLSocket_read_impl(PySSLSocket *self, int len, int group_right_1,
+                          Py_buffer *buffer);
 
 static PyObject *
 _ssl__SSLSocket_read(PySSLSocket *self, PyObject *args)
 {
     PyObject *return_value = NULL;
-    Py_ssize_t len;
+    int len;
     int group_right_1 = 0;
     Py_buffer buffer = {NULL, NULL};
 
     switch (PyTuple_GET_SIZE(args)) {
         case 1:
-            if (!PyArg_ParseTuple(args, "n:read", &len)) {
+            if (!PyArg_ParseTuple(args, "i:read", &len)) {
                 goto exit;
             }
             break;
         case 2:
-            if (!PyArg_ParseTuple(args, "nw*:read", &len, &buffer)) {
+            if (!PyArg_ParseTuple(args, "iw*:read", &len, &buffer)) {
                 goto exit;
             }
             group_right_1 = 1;
@@ -1351,6 +1359,14 @@ _ssl_enum_crls(PyObject *module, PyObject *const *args, Py_ssize_t nargs, PyObje
 
 #endif /* defined(_MSC_VER) */
 
+#ifndef _SSL__SSLSOCKET_GET_VERIFIED_CHAIN_METHODDEF
+    #define _SSL__SSLSOCKET_GET_VERIFIED_CHAIN_METHODDEF
+#endif /* !defined(_SSL__SSLSOCKET_GET_VERIFIED_CHAIN_METHODDEF) */
+
+#ifndef _SSL__SSLSOCKET_GET_UNVERIFIED_CHAIN_METHODDEF
+    #define _SSL__SSLSOCKET_GET_UNVERIFIED_CHAIN_METHODDEF
+#endif /* !defined(_SSL__SSLSOCKET_GET_UNVERIFIED_CHAIN_METHODDEF) */
+
 #ifndef _SSL_ENUM_CERTIFICATES_METHODDEF
     #define _SSL_ENUM_CERTIFICATES_METHODDEF
 #endif /* !defined(_SSL_ENUM_CERTIFICATES_METHODDEF) */
@@ -1358,4 +1374,4 @@ _ssl_enum_crls(PyObject *module, PyObject *const *args, Py_ssize_t nargs, PyObje
 #ifndef _SSL_ENUM_CRLS_METHODDEF
     #define _SSL_ENUM_CRLS_METHODDEF
 #endif /* !defined(_SSL_ENUM_CRLS_METHODDEF) */
-/*[clinic end generated code: output=5a7d7bf5cf8ee092 input=a9049054013a1b77]*/
+/*[clinic end generated code: output=0e12e5e4ee2221b5 input=a9049054013a1b77]*/