Finish crypto wrapping. Also provide wrappers for OpenSSL.

Disable libgcrypt by default. Since it doesn't support the OFB cipher mode,
we can't use it in a backwards compatible way.

src/openssl/rsa.c

@@ -0,0 +1,92 @@
+/*
+    rsa.c -- RSA key handling
+    Copyright (C) 2007 Guus Sliepen <guus@tinc-vpn.org>
+
+    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., 675 Mass Ave, Cambridge, MA 02139, USA.
+
+    $Id$
+*/
+
+#include "system.h"
+
+#include <openssl/pem.h>
+#include <openssl/err.h>
+
+#include "logger.h"
+#include "rsa.h"
+
+// Set RSA keys
+
+bool rsa_set_hex_public_key(rsa_t *rsa, char *n, char *e) {
+	*rsa = RSA_new();
+	BN_hex2bn(&(*rsa)->n, n);
+	BN_hex2bn(&(*rsa)->e, e);
+	return true;
+}
+
+bool rsa_set_hex_private_key(rsa_t *rsa, char *n, char *e, char *d) {
+	*rsa = RSA_new();
+	BN_hex2bn(&(*rsa)->n, n);
+	BN_hex2bn(&(*rsa)->e, e);
+	BN_hex2bn(&(*rsa)->d, d);
+	return true;
+}
+
+// Read PEM RSA keys
+
+bool rsa_read_pem_public_key(rsa_t *rsa, FILE *fp) {
+	*rsa = PEM_read_RSAPublicKey(fp, rsa, NULL, NULL);
+
+	if(*rsa)
+		return true;
+	
+	*rsa = PEM_read_RSA_PUBKEY(fp, rsa, NULL, NULL);
+
+	if(*rsa)
+		return true;
+
+	logger(LOG_ERR, _("Unable to read RSA public key: %s"), ERR_error_string(ERR_get_error(), NULL));
+	return false;
+}
+
+bool rsa_read_pem_private_key(rsa_t *rsa, FILE *fp) {
+	*rsa = PEM_read_RSAPrivateKey(fp, NULL, NULL, NULL);
+
+	if(*rsa)
+		return true;
+	
+	logger(LOG_ERR, _("Unable to read RSA private key: %s"), ERR_error_string(ERR_get_error(), NULL));
+	return false;
+}
+
+size_t rsa_size(rsa_t *rsa) {
+	return RSA_size(*rsa);
+}
+
+bool rsa_public_encrypt(rsa_t *rsa, void *in, size_t len, void *out) {
+	if(RSA_public_encrypt(len, in, out, *rsa, RSA_NO_PADDING) == len)
+		return true;
+
+	logger(LOG_ERR, _("Unable to perform RSA encryption: %s"), ERR_error_string(ERR_get_error(), NULL));
+	return false;	
+}
+
+bool rsa_private_decrypt(rsa_t *rsa, void *in, size_t len, void *out) {
+	if(RSA_private_decrypt(len, in, out, *rsa, RSA_NO_PADDING) == len)
+		return true;
+
+	logger(LOG_ERR, _("Unable to perform RSA decryption: %s"), ERR_error_string(ERR_get_error(), NULL));
+	return false;	
+}