commit 273de864d0a8b4541cbc8c2d38820c9bf5eeb6fd
Author: Bernard Spil <brnrd@FreeBSD.org>
Date:   Wed Aug 31 14:56:35 2016 +0200

    Fix build issues with LibreSSL
    
    LibreSSL defines OPENSSL_VERSION_NUMBER 0x20000000L breaking checks
    for e.g. OpenSSL 1.1.0.
    Additionnaly LibreSSL defines LIBRESSL_VERSION_NUMBER which is
    used in these patches.
    
    Signed-off-by: Bernard Spil <brnrd@FreeBSD.org>

diff --git a/openssl-esp.c b/openssl-esp.c
index 2c1aa49..c41c0d4 100644
--- a/openssl-esp.c
+++ b/openssl-esp.c
@@ -27,7 +27,7 @@
 #include <openssl/evp.h>
 #include <openssl/rand.h>
 
-#if OPENSSL_VERSION_NUMBER < 0x10100000L
+#if OPENSSL_VERSION_NUMBER < 0x10100000L || defined(LIBRESSL_VERSION_NUMBER)
 
 #define EVP_CIPHER_CTX_free(c) do {				\
 				    EVP_CIPHER_CTX_cleanup(c);	\
@@ -85,7 +85,7 @@ static int init_esp_ciphers(struct openconnect_info *vpninfo, struct esp *esp,
 	}
 	EVP_CIPHER_CTX_set_padding(esp->cipher, 0);
 
-#if OPENSSL_VERSION_NUMBER < 0x10100000L
+#if OPENSSL_VERSION_NUMBER < 0x10100000L || defined (LIBRESSL_VERSION_NUMBER)
 	esp->hmac = malloc(sizeof(*esp->hmac));
 	esp->pkt_hmac = malloc(sizeof(*esp->pkt_hmac));
 	if (!esp->hmac || &esp->pkt_hmac) {
diff --git a/openssl.c b/openssl.c
index 3d90436..2bf7e71 100644
--- a/openssl.c
+++ b/openssl.c
@@ -36,7 +36,7 @@
 #include <openssl/ui.h>
 #include <openssl/rsa.h>
 
-#if OPENSSL_VERSION_NUMBER < 0x10100000L
+#if OPENSSL_VERSION_NUMBER < 0x10100000L || defined (LIBRESSL_VERSION_NUMBER)
 #define X509_up_ref(x) 	CRYPTO_add(&(x)->references, 1, CRYPTO_LOCK_X509)
 #define X509_get0_notAfter(x) X509_get_notAfter(x)
 #define EVP_MD_CTX_new EVP_MD_CTX_create
@@ -1068,7 +1068,7 @@ static int set_peer_cert_hash(struct openconnect_info *vpninfo)
 	return 0;
 }
 
-#if OPENSSL_VERSION_NUMBER < 0x10002000L
+#if OPENSSL_VERSION_NUMBER < 0x10002000L || defined (LIBRESSL_VERSION_NUMBER)
 static int match_hostname_elem(const char *hostname, int helem_len,
 			       const char *match, int melem_len)
 {