[spice] relocate openssl code into seperate function

This is in preperation of switching to an alternative SSL library
as OpenSSL conflicts with the GNU licence.

client/spice/rsa.c

@@ -0,0 +1,74 @@
+/*
+Looking Glass - KVM FrameRelay (KVMFR) Client
+Copyright (C) 2017 Geoffrey McRae <geoff@hostfission.com>
+https://looking-glass.hostfission.com
+
+This program is free software; you can redistribute it and/or modify it under
+the terms of the GNU General Public License as published by the Free Software
+Foundation; either version 2 of the License, or (at your option) any later
+version.
+
+This program is distributed in the hope that it will be useful, but WITHOUT ANY
+WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A
+PARTICULAR PURPOSE. See the GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License along with
+this program; if not, write to the Free Software Foundation, Inc., 59 Temple
+Place, Suite 330, Boston, MA 02111-1307 USA
+*/
+
+#include "rsa.h"
+#include "debug.h"
+
+#include <spice/protocol.h>
+#include <string.h>
+
+#include <openssl/rsa.h>
+#include <openssl/evp.h>
+#include <openssl/x509.h>
+
+bool spice_rsa_encrypt_password(uint8_t * pub_key, char * password, struct spice_password * result)
+{
+  BIO *bioKey = BIO_new(BIO_s_mem());
+  if (!bioKey)
+  {
+    DEBUG_ERROR("failed to allocate bioKey");
+    return false;
+  }
+
+  BIO_write(bioKey, pub_key, SPICE_TICKET_PUBKEY_BYTES);
+  EVP_PKEY *rsaKey = d2i_PUBKEY_bio(bioKey, NULL);
+  RSA *rsa = EVP_PKEY_get1_RSA(rsaKey);
+
+  result->size = RSA_size(rsa);
+  result->data = (char *)malloc(result->size);
+
+  if (RSA_public_encrypt(
+        strlen(password) + 1,
+        (uint8_t*)password,
+        (uint8_t*)result->data,
+        rsa,
+        RSA_PKCS1_OAEP_PADDING
+  ) <= 0)
+  {
+    free(result->data);
+    result->size = 0;
+    result->data = NULL;
+
+    DEBUG_ERROR("rsa public encrypt failed");
+    EVP_PKEY_free(rsaKey);
+    BIO_free(bioKey);
+    return false;
+  }
+
+  EVP_PKEY_free(rsaKey);
+  BIO_free(bioKey);
+  return true;
+}
+
+void spice_rsa_free_password(struct spice_password * pass)
+{
+  free(pass->data);
+  pass->size = 0;
+  pass->data = NULL;
+}