Improve AES-CTR check.

configure.ac

@@ -111,6 +111,14 @@ if test "$ac_cv_libgcrypt" = "yes"; then
 fi
 AM_CONDITIONAL(LIBGCRYPT, test "$ac_cv_libgcrypt" = "yes")
 
+# Not all OpenSSL have AES-CTR functions.
+if test "$ac_cv_libssl" = "yes"; then
+  save_LDFLAGS="$LDFLAGS"
+  LDFLAGS="$LDFLAGS $LIBSSL"
+  AC_CHECK_FUNCS(EVP_aes128_ctr)
+  LDFLAGS="$save_LDFLAGS"
+fi
+
 # Look for Libz
 if test "$use_libz" != "no"; then
   AC_LIB_HAVE_LINKFLAGS([z], [], [#include <zlib.h>])

src/openssl.c

@@ -201,7 +201,7 @@ _libssh2_cipher_crypt(_libssh2_cipher_ctx * ctx,
     return ret == 1 ? 0 : 1;
 }
 
-#if LIBSSH2_AES_CTR && OPENSSL_VERSION_NUMBER < 0x0090808fL
+#if LIBSSH2_AES_CTR && !HAVE_EVP_AES128_CTR
 
 #include <openssl/aes.h>
 

src/openssl.h

@@ -198,7 +198,7 @@ int _libssh2_dsa_sha1_sign(libssh2_dsa_ctx * dsactx,
 #define _libssh2_cipher_aes256 EVP_aes_256_cbc
 #define _libssh2_cipher_aes192 EVP_aes_192_cbc
 #define _libssh2_cipher_aes128 EVP_aes_128_cbc
-#if OPENSSL_VERSION_NUMBER >= 0x0090808fL
+#if HAVE_EVP_AES128_CTR
 #define _libssh2_cipher_aes128ctr EVP_aes_128_ctr
 #define _libssh2_cipher_aes192ctr EVP_aes_192_ctr
 #define _libssh2_cipher_aes256ctr EVP_aes_256_ctr