pki: Fix building pki_ed25519.c with libgcrypt

Signed-off-by: Andreas Schneider <asn@cryptomilk.org>
Reviewed-by: Jakub Jelen <jjelen@redhat.com>
(cherry picked from commit 6a25f07777337637bfa54ff18bb9705db4461bf8)

include/libssh/pki.h

@@ -33,7 +33,7 @@
 #include <openssl/evp.h>
 #endif
 #include "libssh/crypto.h"
-#ifdef HAVE_OPENSSL_ED25519
+#if defined(HAVE_LIBCRYPTO) && defined(HAVE_OPENSSL_ED25519)
 /* If using OpenSSL implementation, define the signature lenght which would be
  * defined in libssh/ed25519.h otherwise */
 #define ED25519_SIG_LEN 64
@@ -80,7 +80,7 @@ struct ssh_key_struct {
 # endif /* HAVE_OPENSSL_EC_H */
     EVP_PKEY *key; /* Saving the OpenSSL context here to save time while converting*/
 #endif /* HAVE_LIBGCRYPT */
-#ifdef HAVE_OPENSSL_ED25519
+#if defined(HAVE_LIBCRYPTO) && defined(HAVE_OPENSSL_ED25519)
     uint8_t *ed25519_pubkey;
     uint8_t *ed25519_privkey;
 #else
@@ -104,7 +104,7 @@ struct ssh_signature_struct {
     ssh_string rsa_sig;
     struct mbedtls_ecdsa_sig ecdsa_sig;
 #endif /* HAVE_LIBGCRYPT */
-#ifndef HAVE_OPENSSL_ED25519
+#if !defined(HAVE_LIBCRYPTO) || !defined(HAVE_OPENSSL_ED25519)
     ed25519_signature *ed25519_sig;
 #endif
     ssh_string raw_sig;