Parse PEM RSA keys ourself, and use libgcrypt to do RSA encryption and decryption.

configure.in

@@ -145,6 +145,7 @@ AC_CACHE_SAVE
 
 dnl These are defined in files in m4/
 
+AM_PATH_LIBGCRYPT([], [], [AC_MSG_ERROR([Libgcrypt not found.]); break])
 tinc_OPENSSL
 tinc_ZLIB
 tinc_LZO

src/Makefile.am

@@ -7,7 +7,7 @@ EXTRA_DIST = linux/device.c bsd/device.c solaris/device.c cygwin/device.c mingw/
 
 tincd_SOURCES = conf.c connection.c control.c edge.c graph.c logger.c meta.c net.c net_packet.c net_setup.c	\
 	net_socket.c netutl.c node.c process.c protocol.c protocol_auth.c protocol_edge.c protocol_misc.c	\
-	protocol_key.c protocol_subnet.c route.c subnet.c tincd.c
+	protocol_key.c protocol_subnet.c route.c rsa.c subnet.c tincd.c
 
 tincctl_SOURCES = tincctl.c
 
@@ -18,12 +18,13 @@ DEFAULT_INCLUDES =
 INCLUDES = @INCLUDES@ -I$(top_builddir) -I$(top_srcdir)/lib
 
 noinst_HEADERS = conf.h connection.h control.h device.h edge.h graph.h logger.h meta.h net.h netutl.h node.h process.h	\
-	protocol.h route.h subnet.h
+	protocol.h route.h rsa.h subnet.h
 
 LIBS = @LIBS@ @LIBINTL@
 
 tincd_LDADD = \
-	$(top_builddir)/lib/libvpn.a
+	$(top_builddir)/lib/libvpn.a \
+	$(LIBGCRYPT_LIBS)
 
 tincctl_LDADD = \
 	$(top_builddir)/lib/libvpn.a
@@ -31,6 +32,7 @@ tincctl_LDADD = \
 localedir = $(datadir)/locale
 
 AM_CFLAGS = @CFLAGS@ -DCONFDIR=\"$(sysconfdir)\" -DLOCALEDIR=\"$(localedir)\" -DLOCALSTATEDIR=\"$(localstatedir)\"
+tinc_CPPFLAGS = $(LIBGCRYPT_CFLAGS)
 
 dist-hook:
 	rm -f `find . -type l`

src/connection.h

@@ -23,11 +23,12 @@
 #ifndef __TINC_CONNECTION_H__
 #define __TINC_CONNECTION_H__
 
-#include <openssl/rsa.h>
+//#include <openssl/rsa.h>
 #include <openssl/evp.h>
 
 #include <event.h>
 
+#include "rsa.h"
 #include "splay_tree.h"
 
 #define OPTION_INDIRECT		0x0001
@@ -72,7 +73,8 @@ typedef struct connection_t {
 	struct node_t *node;		/* node associated with the other end */
 	struct edge_t *edge;		/* edge associated with this connection */
 
-	RSA *rsa_key;				/* his public/private key */
+	//RSA *rsa_key;				/* his public/private key */
+	struct rsa_key_t rsa_key;          /* his public/private key */
 	const EVP_CIPHER *incipher;	/* Cipher he will use to send data to us */
 	const EVP_CIPHER *outcipher;	/* Cipher we will use to send data to him */
 	EVP_CIPHER_CTX *inctx;		/* Context of encrypted meta data that will come from him to us */

src/net_setup.c

@@ -22,6 +22,8 @@
 
 #include "system.h"
 
+#include <gcrypt.h>
+
 #include <openssl/pem.h>
 #include <openssl/rsa.h>
 #include <openssl/rand.h>
@@ -40,6 +42,7 @@
 #include "process.h"
 #include "protocol.h"
 #include "route.h"
+#include "rsa.h"
 #include "subnet.h"
 #include "utils.h"
 #include "xalloc.h"
@@ -50,125 +53,38 @@ static struct event device_ev;
 bool read_rsa_public_key(connection_t *c) {
 	FILE *fp;
 	char *fname;
-	char *key;
+	bool result;
 
 	cp();
 
-	if(!c->rsa_key) {
+	if(!get_config_string(lookup_config(c->config_tree, "PublicKeyFile"), &fname))
-		c->rsa_key = RSA_new();
+		asprintf(&fname, "%s/hosts/%s", confbase, c->name);
-//		RSA_blinding_on(c->rsa_key, NULL);
-	}
 
-	/* First, check for simple PublicKey statement */
+	fp = fopen(fname, "r");
 
-	if(get_config_string(lookup_config(c->config_tree, "PublicKey"), &key)) {
+	if(!fp) {
-		BN_hex2bn(&c->rsa_key->n, key);
+		logger(LOG_ERR, _("Error reading RSA public key file `%s': %s"),
-		BN_hex2bn(&c->rsa_key->e, "FFFF");
-		free(key);
-		return true;
-	}
-
-	/* Else, check for PublicKeyFile statement and read it */
-
-	if(get_config_string(lookup_config(c->config_tree, "PublicKeyFile"), &fname)) {
-		fp = fopen(fname, "r");
-
-		if(!fp) {
-			logger(LOG_ERR, _("Error reading RSA public key file `%s': %s"),
-				   fname, strerror(errno));
-			free(fname);
-			return false;
-		}
-
-		free(fname);
-		c->rsa_key = PEM_read_RSAPublicKey(fp, &c->rsa_key, NULL, NULL);
-		fclose(fp);
-
-		if(c->rsa_key)
-			return true;		/* Woohoo. */
-
-		/* If it fails, try PEM_read_RSA_PUBKEY. */
-		fp = fopen(fname, "r");
-
-		if(!fp) {
-			logger(LOG_ERR, _("Error reading RSA public key file `%s': %s"),
-				   fname, strerror(errno));
-			free(fname);
-			return false;
-		}
-
-		free(fname);
-		c->rsa_key = PEM_read_RSA_PUBKEY(fp, &c->rsa_key, NULL, NULL);
-		fclose(fp);
-
-		if(c->rsa_key) {
-//				RSA_blinding_on(c->rsa_key, NULL);
-			return true;
-		}
-
-		logger(LOG_ERR, _("Reading RSA public key file `%s' failed: %s"),
 			   fname, strerror(errno));
+		free(fname);
 		return false;
 	}
 
-	/* Else, check if a harnessed public key is in the config file */
+	result = read_pem_rsa_public_key(fp, &c->rsa_key);
-
+	fclose(fp);
-	asprintf(&fname, "%s/hosts/%s", confbase, c->name);
-	fp = fopen(fname, "r");
-
-	if(fp) {
-		c->rsa_key = PEM_read_RSAPublicKey(fp, &c->rsa_key, NULL, NULL);
-		fclose(fp);
-	}
 
+	if(!result) 
+		logger(LOG_ERR, _("Reading RSA public key file `%s' failed: %s"), fname, strerror(errno));
 	free(fname);
-
+	return result;
-	if(c->rsa_key)
-		return true;
-
-	/* Try again with PEM_read_RSA_PUBKEY. */
-
-	asprintf(&fname, "%s/hosts/%s", confbase, c->name);
-	fp = fopen(fname, "r");
-
-	if(fp) {
-		c->rsa_key = PEM_read_RSA_PUBKEY(fp, &c->rsa_key, NULL, NULL);
-//		RSA_blinding_on(c->rsa_key, NULL);
-		fclose(fp);
-	}
-
-	free(fname);
-
-	if(c->rsa_key)
-		return true;
-
-	logger(LOG_ERR, _("No public key for %s specified!"), c->name);
-
-	return false;
 }
 
-bool read_rsa_private_key(void) {
+bool read_rsa_private_key() {
 	FILE *fp;
-	char *fname, *key, *pubkey;
+	char *fname;
-	struct stat s;
+	bool result;
 
 	cp();
 
-	if(get_config_string(lookup_config(config_tree, "PrivateKey"), &key)) {
-		if(!get_config_string(lookup_config(myself->connection->config_tree, "PublicKey"), &pubkey)) {
-			logger(LOG_ERR, _("PrivateKey used but no PublicKey found!"));
-			return false;
-		}
-		myself->connection->rsa_key = RSA_new();
-//		RSA_blinding_on(myself->connection->rsa_key, NULL);
-		BN_hex2bn(&myself->connection->rsa_key->d, key);
-		BN_hex2bn(&myself->connection->rsa_key->n, pubkey);
-		BN_hex2bn(&myself->connection->rsa_key->e, "FFFF");
-		free(key);
-		free(pubkey);
-		return true;
-	}
-
 	if(!get_config_string(lookup_config(config_tree, "PrivateKeyFile"), &fname))
 		asprintf(&fname, "%s/rsa_key.priv", confbase);
 
@@ -182,9 +98,10 @@ bool read_rsa_private_key(void) {
 	}
 
 #if !defined(HAVE_MINGW) && !defined(HAVE_CYGWIN)
+	struct stat s;
+
 	if(fstat(fileno(fp), &s)) {
-		logger(LOG_ERR, _("Could not stat RSA private key file `%s': %s'"),
+		logger(LOG_ERR, _("Could not stat RSA private key file `%s': %s'"), fname, strerror(errno));
-				fname, strerror(errno));
 		free(fname);
 		return false;
 	}
@@ -193,18 +110,13 @@ bool read_rsa_private_key(void) {
 		logger(LOG_WARNING, _("Warning: insecure file permissions for RSA private key file `%s'!"), fname);
 #endif
 
-	myself->connection->rsa_key = PEM_read_RSAPrivateKey(fp, NULL, NULL, NULL);
+	result = read_pem_rsa_private_key(fp, &myself->connection->rsa_key);
 	fclose(fp);
 
-	if(!myself->connection->rsa_key) {
+	if(!result) 
-		logger(LOG_ERR, _("Reading RSA private key file `%s' failed: %s"),
+		logger(LOG_ERR, _("Reading RSA private key file `%s' failed: %s"), fname, strerror(errno));
-			   fname, strerror(errno));
-		free(fname);
-		return false;
-	}
-
 	free(fname);
-	return true;
+	return result;
 }
 
 static struct event keyexpire_event;

src/protocol_auth.c

@@ -37,6 +37,7 @@
 #include "netutl.h"
 #include "node.h"
 #include "protocol.h"
+#include "rsa.h"
 #include "utils.h"
 #include "xalloc.h"
 
@@ -116,12 +117,12 @@ bool id_h(connection_t *c, char *request) {
 
 bool send_metakey(connection_t *c) {
 	char *buffer;
-	int len;
+	unsigned int len;
 	bool x;
 
 	cp();
 
-	len = RSA_size(c->rsa_key);
+	len = get_rsa_size(&c->rsa_key);
 
 	/* Allocate buffers for the meta key */
 
@@ -163,7 +164,7 @@ bool send_metakey(connection_t *c) {
 	   with a length equal to that of the modulus of the RSA key.
 	 */
 
-	if(RSA_public_encrypt(len, (unsigned char *)c->outkey, (unsigned char *)buffer, c->rsa_key, RSA_NO_PADDING) != len) {
+	if(!rsa_public_encrypt(len, (unsigned char *)c->outkey, (unsigned char *)buffer, &c->rsa_key)) {
 		logger(LOG_ERR, _("Error during encryption of meta key for %s (%s)"),
 			   c->name, c->hostname);
 		return false;
@@ -212,7 +213,7 @@ bool metakey_h(connection_t *c, char *request) {
 		return false;
 	}
 
-	len = RSA_size(myself->connection->rsa_key);
+	len = get_rsa_size(&myself->connection->rsa_key);
 
 	/* Check if the length of the meta key is all right */
 
@@ -235,9 +236,8 @@ bool metakey_h(connection_t *c, char *request) {
 
 	/* Decrypt the meta key */
 
-	if(RSA_private_decrypt(len, (unsigned char *)buffer, (unsigned char *)c->inkey, myself->connection->rsa_key, RSA_NO_PADDING) != len) {	/* See challenge() */
+	if(!rsa_private_decrypt(len, (unsigned char *)buffer, (unsigned char *)c->inkey, &myself->connection->rsa_key)) {
-		logger(LOG_ERR, _("Error during encryption of meta key for %s (%s)"),
+		logger(LOG_ERR, _("Error during encryption of meta key for %s (%s)"), c->name, c->hostname);
-			   c->name, c->hostname);
 		return false;
 	}
 
@@ -306,7 +306,7 @@ bool send_challenge(connection_t *c) {
 
 	/* CHECKME: what is most reasonable value for len? */
 
-	len = RSA_size(c->rsa_key);
+	len = get_rsa_size(&c->rsa_key);
 
 	/* Allocate buffers for the challenge */
 
@@ -341,7 +341,7 @@ bool challenge_h(connection_t *c, char *request) {
 		return false;
 	}
 
-	len = RSA_size(myself->connection->rsa_key);
+	len = get_rsa_size(&myself->connection->rsa_key);
 
 	/* Check if the length of the challenge is all right */
 
@@ -376,7 +376,7 @@ bool send_chal_reply(connection_t *c) {
 	/* Calculate the hash from the challenge we received */
 
 	if(!EVP_DigestInit(&ctx, c->indigest)
-			|| !EVP_DigestUpdate(&ctx, c->mychallenge, RSA_size(myself->connection->rsa_key))
+			|| !EVP_DigestUpdate(&ctx, c->mychallenge, get_rsa_size(&myself->connection->rsa_key))
 			|| !EVP_DigestFinal(&ctx, (unsigned char *)hash, NULL)) {
 		logger(LOG_ERR, _("Error during calculation of response for %s (%s): %s"),
 			c->name, c->hostname, ERR_error_string(ERR_get_error(), NULL));
@@ -421,7 +421,7 @@ bool chal_reply_h(connection_t *c, char *request) {
 	/* Calculate the hash from the challenge we sent */
 
 	if(!EVP_DigestInit(&ctx, c->outdigest)
-			|| !EVP_DigestUpdate(&ctx, c->hischallenge, RSA_size(c->rsa_key))
+			|| !EVP_DigestUpdate(&ctx, c->hischallenge, get_rsa_size(&c->rsa_key))
 			|| !EVP_DigestFinal(&ctx, (unsigned char *)myhash, NULL)) {
 		logger(LOG_ERR, _("Error during calculation of response from %s (%s): %s"),
 			c->name, c->hostname, ERR_error_string(ERR_get_error(), NULL));

src/rsa.c

@@ -0,0 +1,269 @@
+/*
+    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 <gcrypt.h>
+
+#include "logger.h"
+#include "rsa.h"
+
+// Base64 encoding/decoding tables
+
+static const uint8_t b64d[128] = {
+  0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+  0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+  0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+  0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+  0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+  0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+  0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+  0xff, 0x3e, 0xff, 0xff, 0xff, 0x3f,
+  0x34, 0x35, 0x36, 0x37, 0x38, 0x39,
+  0x3a, 0x3b, 0x3c, 0x3d, 0xff, 0xff,
+  0xff, 0xff, 0xff, 0xff, 0xff, 0x00,
+  0x01, 0x02, 0x03, 0x04, 0x05, 0x06,
+  0x07, 0x08, 0x09, 0x0a, 0x0b, 0x0c,
+  0x0d, 0x0e, 0x0f, 0x10, 0x11, 0x12,
+  0x13, 0x14, 0x15, 0x16, 0x17, 0x18,
+  0x19, 0xff, 0xff, 0xff, 0xff, 0xff,
+  0xff, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e,
+  0x1f, 0x20, 0x21, 0x22, 0x23, 0x24,
+  0x25, 0x26, 0x27, 0x28, 0x29, 0x2a,
+  0x2b, 0x2c, 0x2d, 0x2e, 0x2f, 0x30,
+  0x31, 0x32, 0x33, 0xff, 0xff, 0xff,
+  0xff, 0xff
+};
+
+static const char b64e[64] = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
+
+// PEM encoding/decoding functions
+
+static bool pem_decode(FILE *fp, const char *header, uint8_t *buf, size_t size, size_t *outsize) {
+	bool decode = false;
+	char line[1024];
+	uint16_t word = 0;
+	int shift = 10;
+	size_t i, j = 0;
+
+	while(!feof(fp)) {
+		if(!fgets(line, sizeof line, fp))
+			return false;
+
+		if(!decode && !strncmp(line, "-----BEGIN ", 11)) {
+			if(!strncmp(line + 11, header, strlen(header)))
+				decode = true;
+			continue;
+		}
+
+		if(decode && !strncmp(line, "-----END", 8)) {
+			break;
+		}
+
+		if(!decode)
+			continue;
+
+		for(i = 0; line[i] >= ' '; i++) {
+			if(line[i] >= 128 || line[i] < 0 || b64d[(int)line[i]] == 0xff)
+				break;
+			word |= b64d[(int)line[i]] << shift;
+			shift -= 6;
+			if(shift <= 2) {
+				if(j > size) {
+					errno = ENOMEM;
+					return false;
+				}
+
+				buf[j++] = word >> 8;
+				word <<= 8;
+				shift += 8;
+			}
+		}
+	}
+
+	if(outsize)
+		*outsize = j;
+	return true;
+}
+
+
+// BER decoding functions
+
+static int ber_read_id(unsigned char **p, size_t *buflen) {
+	if(*buflen <= 0)
+		return -1;
+
+	if((**p & 0x1f) == 0x1f) {
+		int id = 0;
+		bool more;
+		while(*buflen > 0) {
+			id <<= 7;
+			id |= **p & 0x7f;
+			more = *(*p)++ & 0x80;
+			(*buflen)--;
+			if(!more)
+				break;
+		}
+		return id;
+	} else {
+		(*buflen)--;
+		return *(*p)++ & 0x1f;
+	}
+}
+
+static size_t ber_read_len(unsigned char **p, size_t *buflen) {
+	if(*buflen <= 0)
+		return -1;
+
+	if(**p & 0x80) {
+		size_t result = 0;
+		int len = *(*p)++ & 0x7f;
+		(*buflen)--;
+		if(len > *buflen)
+			return 0;
+
+		while(len--) {
+			result <<= 8;
+			result |= *(*p)++;
+			(*buflen)--;
+		}
+
+		return result;
+	} else {
+		(*buflen)--;
+		return *(*p)++;
+	}
+}
+	
+
+static bool ber_read_sequence(unsigned char **p, size_t *buflen, size_t *result) {
+	int tag = ber_read_id(p, buflen);
+	size_t len = ber_read_len(p, buflen);
+
+	if(tag == 0x10) {
+		if(result)
+			*result = len;
+		return true;
+	} else {
+		return false;
+	}
+}
+
+static bool ber_read_mpi(unsigned char **p, size_t *buflen, gcry_mpi_t *mpi) {
+	int tag = ber_read_id(p, buflen);
+	size_t len = ber_read_len(p, buflen);
+	gcry_error_t err = 0;
+
+	if(tag != 0x02 || len > *buflen)
+		return false;
+
+	if(mpi)
+		err = gcry_mpi_scan(mpi, GCRYMPI_FMT_USG, *p, len, NULL);
+	
+	*p += len;
+	*buflen -= len;
+
+	return mpi ? !err : true;
+}
+
+// Read PEM RSA keys
+
+bool read_pem_rsa_public_key(FILE *fp, rsa_key_t *key) {
+	uint8_t derbuf[8096], *derp = derbuf;
+	size_t derlen;
+
+	if(!pem_decode(fp, "RSA PUBLIC KEY", derbuf, sizeof derbuf, &derlen)) {
+		logger(LOG_ERR, _("Unable to read RSA public key: %s"), strerror(errno));
+		return NULL;
+	}
+
+	if(!ber_read_sequence(&derp, &derlen, NULL)
+			|| !ber_read_mpi(&derp, &derlen, &key->n)
+			|| !ber_read_mpi(&derp, &derlen, &key->e)
+			|| derlen) {
+		logger(LOG_ERR, _("Error while decoding RSA public key"));
+		return NULL;
+	}
+
+	return true;
+}
+
+bool read_pem_rsa_private_key(FILE *fp, rsa_key_t *key) {
+	uint8_t derbuf[8096], *derp = derbuf;
+	size_t derlen;
+
+	if(!pem_decode(fp, "RSA PRIVATE KEY", derbuf, sizeof derbuf, &derlen)) {
+		logger(LOG_ERR, _("Unable to read RSA private key: %s"), strerror(errno));
+		return NULL;
+	}
+
+	if(!ber_read_sequence(&derp, &derlen, NULL)
+			|| !ber_read_mpi(&derp, &derlen, NULL)
+			|| !ber_read_mpi(&derp, &derlen, &key->n)
+			|| !ber_read_mpi(&derp, &derlen, &key->e)
+			|| !ber_read_mpi(&derp, &derlen, &key->d)
+			|| !ber_read_mpi(&derp, &derlen, NULL) // p
+			|| !ber_read_mpi(&derp, &derlen, NULL) // q
+			|| !ber_read_mpi(&derp, &derlen, NULL)
+			|| !ber_read_mpi(&derp, &derlen, NULL)
+			|| !ber_read_mpi(&derp, &derlen, NULL) // u
+			|| derlen) {
+		logger(LOG_ERR, _("Error while decoding RSA private key"));
+		return NULL;
+	}
+
+	return true;
+}
+
+unsigned int get_rsa_size(rsa_key_t *key) {
+	return (gcry_mpi_get_nbits(key->n) + 7) / 8;
+}
+
+/* Well, libgcrypt has functions to handle RSA keys, but they suck.
+ * So we just use libgcrypt's mpi functions, and do the math ourselves.
+ */
+
+// TODO: get rid of this macro, properly clean up gcry_ structures after use
+#define check(foo) { gcry_error_t err = (foo); if(err) {logger(LOG_ERR, "gcrypt error %s/%s at %s:%d\n", gcry_strsource(err), gcry_strerror(err), __FILE__, __LINE__); return false; }}
+
+bool rsa_public_encrypt(size_t len, void *in, void *out, rsa_key_t *key) {
+	gcry_mpi_t inmpi;
+	check(gcry_mpi_scan(&inmpi, GCRYMPI_FMT_USG, in, len, NULL));
+
+	gcry_mpi_t outmpi = gcry_mpi_new(len * 8);
+	gcry_mpi_powm(outmpi, inmpi, key->e, key->n);
+
+	check(gcry_mpi_print(GCRYMPI_FMT_USG, out,len, NULL, outmpi));
+
+	return true;
+}
+
+bool rsa_private_decrypt(size_t len, void *in, void *out, rsa_key_t *key) {
+	gcry_mpi_t inmpi;
+	check(gcry_mpi_scan(&inmpi, GCRYMPI_FMT_USG, in, len, NULL));
+
+	gcry_mpi_t outmpi = gcry_mpi_new(len * 8);
+	gcry_mpi_powm(outmpi, inmpi, key->d, key->n);
+
+	check(gcry_mpi_print(GCRYMPI_FMT_USG, out,len, NULL, outmpi));
+
+	return true;
+}

src/rsa.h

@@ -0,0 +1,40 @@
+/*
+    rsa.h -- 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.
+
+    $Id$
+*/
+
+#ifndef __TINC_RSA_H__
+#define __TINC_RSA_H__
+
+#include <gcrypt.h>
+
+typedef struct rsa_key_t {
+	gcry_mpi_t n;
+	gcry_mpi_t e;
+	gcry_mpi_t d;
+} rsa_key_t;
+
+extern bool read_pem_rsa_public_key(FILE *fp, struct rsa_key_t *key);
+extern bool read_pem_rsa_private_key(FILE *fp, struct rsa_key_t *key);
+extern unsigned int get_rsa_size(struct rsa_key_t *key);
+extern bool rsa_public_encrypt(size_t len, void *in, void *out, struct rsa_key_t *key);
+extern bool rsa_private_decrypt(size_t len, void *in, void *out, struct rsa_key_t *key);
+
+
+#endif