From: Guus Sliepen <guus@tinc-vpn.org>
Date: Thu, 11 Dec 2008 14:44:44 +0000 (+0000)
Subject: Use the crypto wrappers again instead of calling OpenSSL directly.
X-Git-Tag: release-1.1pre1~129
X-Git-Url: https://tinc-vpn.org/git/browse?p=tinc;a=commitdiff_plain;h=046158a216e78a0412186ec8463157f6bce45d5d

Use the crypto wrappers again instead of calling OpenSSL directly.
This theoretically allows other cryptographic libraries to be used,
and it improves the readability of the code.
---

diff --git a/src/connection.c b/src/connection.c
index 06f51b50..84d2ac4d 100644
--- a/src/connection.c
+++ b/src/connection.c
@@ -23,6 +23,7 @@
 #include "system.h"
 
 #include "splay_tree.h"
+#include "cipher.h"
 #include "conf.h"
 #include "list.h"
 #include "logger.h"
@@ -73,14 +74,8 @@ void free_connection(connection_t *c) {
 	if(c->hostname)
 		free(c->hostname);
 
-	if(c->inkey)
-		free(c->inkey);
-
-	if(c->outkey)
-		free(c->outkey);
-
-	if(c->mychallenge)
-		free(c->mychallenge);
+	cipher_close(&c->incipher);
+	cipher_close(&c->outcipher);
 
 	if(c->hischallenge)
 		free(c->hischallenge);
diff --git a/src/connection.h b/src/connection.h
index ddff03bb..ca71cad9 100644
--- a/src/connection.h
+++ b/src/connection.h
@@ -23,11 +23,11 @@
 #ifndef __TINC_CONNECTION_H__
 #define __TINC_CONNECTION_H__
 
-#include <openssl/rsa.h>
-#include <openssl/evp.h>
-
 #include <event.h>
 
+#include "cipher.h"
+#include "digest.h"
+#include "rsa.h"
 #include "splay_tree.h"
 
 #define OPTION_INDIRECT		0x0001
@@ -72,23 +72,18 @@ 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 */
-	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 */
-	EVP_CIPHER_CTX *outctx;		/* Context of encrypted meta data that will be sent from us to him */
-	char *inkey;				/* His symmetric meta key + iv */
-	char *outkey;				/* Our symmetric meta key + iv */
-	int inkeylength;			/* Length of his key + iv */
-	int outkeylength;			/* Length of our key + iv */
-	const EVP_MD *indigest;
-	const EVP_MD *outdigest;
+	rsa_t rsa;			/* his public/private key */
+	cipher_t incipher;		/* Cipher he will use to send data to us */
+	cipher_t outcipher;		/* Cipher we will use to send data to him */
+	digest_t indigest;
+	digest_t outdigest;
+
 	int inmaclength;
 	int outmaclength;
 	int incompression;
 	int outcompression;
-	char *mychallenge;			/* challenge we received from him */
-	char *hischallenge;			/* challenge we sent to him */
+
+	char *hischallenge;		/* The challenge we sent to him */
 
 	struct bufferevent *buffer;			/* buffer events on this metadata connection */
 	struct event inevent;				/* input event on this metadata connection */
diff --git a/src/meta.c b/src/meta.c
index cb4b03e1..aaa5c30c 100644
--- a/src/meta.c
+++ b/src/meta.c
@@ -22,10 +22,8 @@
 
 #include "system.h"
 
-#include <openssl/err.h>
-#include <openssl/evp.h>
-
 #include "splay_tree.h"
+#include "cipher.h"
 #include "connection.h"
 #include "logger.h"
 #include "meta.h"
@@ -35,8 +33,6 @@
 #include "xalloc.h"
 
 bool send_meta(connection_t *c, const char *buffer, int length) {
-	int outlen;
-	int result;
 	cp();
 
 	ifdebug(META) logger(LOG_DEBUG, _("Sending %d bytes of metadata to %s (%s)"), length,
@@ -45,11 +41,11 @@ bool send_meta(connection_t *c, const char *buffer, int length) {
 	/* Add our data to buffer */
 	if(c->status.encryptout) {
 		char outbuf[length];
+		size_t outlen = length;
 
-		result = EVP_EncryptUpdate(c->outctx, (unsigned char *)outbuf, &outlen, (unsigned char *)buffer, length);
-		if(!result || outlen != length) {
-			logger(LOG_ERR, _("Error while encrypting metadata to %s (%s): %s"),
-					c->name, c->hostname, ERR_error_string(ERR_get_error(), NULL));
+		if(!cipher_encrypt(&c->outcipher, buffer, length, outbuf, &outlen, false) || outlen != length) {
+			logger(LOG_ERR, _("Error while encrypting metadata to %s (%s)"),
+					c->name, c->hostname);
 			return false;
 		}
 		
@@ -80,7 +76,7 @@ void broadcast_meta(connection_t *from, const char *buffer, int length) {
 }
 
 bool receive_meta(connection_t *c) {
-	int result, inlen, outlen;
+	size_t inlen;
 	char inbuf[MAXBUFSIZE];
 	char *bufp = inbuf, *endp;
 
@@ -115,12 +111,13 @@ bool receive_meta(connection_t *c) {
 			inlen -= endp - bufp;
 			bufp = endp;
 		} else {
+			size_t outlen = inlen;
 			ifdebug(META) logger(LOG_DEBUG, _("Received encrypted %d bytes"), inlen);
 			evbuffer_expand(c->buffer->input, c->buffer->input->off + inlen);
-			result = EVP_DecryptUpdate(c->inctx, (unsigned char *)c->buffer->input->buffer + c->buffer->input->off, &outlen, (unsigned char *)bufp, inlen);
-			if(!result || outlen != inlen) {
-				logger(LOG_ERR, _("Error while decrypting metadata from %s (%s): %s"),
-					   c->name, c->hostname, ERR_error_string(ERR_get_error(), NULL));
+
+			if(!cipher_decrypt(&c->incipher, bufp, inlen, c->buffer->input->buffer + c->buffer->input->off, &outlen, false) || inlen != outlen) {
+				logger(LOG_ERR, _("Error while decrypting metadata from %s (%s)"),
+					   c->name, c->hostname);
 				return false;
 			}
 			c->buffer->input->off += inlen;
@@ -146,8 +143,10 @@ bool receive_meta(connection_t *c) {
 
 			char *request = evbuffer_readline(c->buffer->input);
 			if(request) {
-				receive_request(c, request);
+				bool result = receive_request(c, request);
 				free(request);
+				if(!result)
+					return false;
 				continue;
 			} else {
 				break;
diff --git a/src/net_packet.c b/src/net_packet.c
index 2a86d657..eee3972e 100644
--- a/src/net_packet.c
+++ b/src/net_packet.c
@@ -22,18 +22,15 @@
 
 #include "system.h"
 
-#include <openssl/rand.h>
-#include <openssl/err.h>
-#include <openssl/evp.h>
-#include <openssl/pem.h>
-#include <openssl/hmac.h>
-
 #include <zlib.h>
 #include LZO1X_H
 
 #include "splay_tree.h"
+#include "cipher.h"
 #include "conf.h"
 #include "connection.h"
+#include "crypto.h"
+#include "digest.h"
 #include "device.h"
 #include "ethernet.h"
 #include "graph.h"
@@ -52,7 +49,6 @@
 #endif
 
 int keylifetime = 0;
-EVP_CIPHER_CTX packet_ctx;
 static char lzo_wrkmem[LZO1X_999_MEM_COMPRESS > LZO1X_1_MEM_COMPRESS ? LZO1X_999_MEM_COMPRESS : LZO1X_1_MEM_COMPRESS];
 
 static void send_udppacket(node_t *, vpn_packet_t *);
@@ -85,7 +81,7 @@ static void send_mtu_probe_handler(int fd, short events, void *data) {
 			len = 64;
 		
 		memset(packet.data, 0, 14);
-		RAND_pseudo_bytes(packet.data + 14, len - 14);
+		randomize(packet.data + 14, len - 14);
 		packet.len = len;
 
 		ifdebug(TRAFFIC) logger(LOG_INFO, _("Sending MTU probe length %d to %s (%s)"), len, n->name, n->hostname);
@@ -168,15 +164,14 @@ static void receive_udppacket(node_t *n, vpn_packet_t *inpkt) {
 	vpn_packet_t *pkt[] = { &pkt1, &pkt2, &pkt1, &pkt2 };
 	int nextpkt = 0;
 	vpn_packet_t *outpkt = pkt[0];
-	int outlen, outpad;
-	unsigned char hmac[EVP_MAX_MD_SIZE];
+	size_t outlen;
 	int i;
 
 	cp();
 
 	/* Check packet length */
 
-	if(inpkt->len < sizeof(inpkt->seqno) + myself->maclength) {
+	if(inpkt->len < sizeof(inpkt->seqno) + digest_length(&myself->digest)) {
 		ifdebug(TRAFFIC) logger(LOG_DEBUG, _("Got too short packet from %s (%s)"),
 					n->name, n->hostname);
 		return;
@@ -184,33 +179,23 @@ static void receive_udppacket(node_t *n, vpn_packet_t *inpkt) {
 
 	/* Check the message authentication code */
 
-	if(myself->digest && myself->maclength) {
-		inpkt->len -= myself->maclength;
-		HMAC(myself->digest, myself->key, myself->keylength,
-			 (unsigned char *) &inpkt->seqno, inpkt->len, (unsigned char *)hmac, NULL);
-
-		if(memcmp(hmac, (char *) &inpkt->seqno + inpkt->len, myself->maclength)) {
-			ifdebug(TRAFFIC) logger(LOG_DEBUG, _("Got unauthenticated packet from %s (%s)"),
-					   n->name, n->hostname);
-			return;
-		}
+	if(digest_active(&myself->digest) && !digest_verify(&myself->digest, &inpkt->seqno, inpkt->len, &inpkt->seqno + inpkt->len)) {
+		ifdebug(TRAFFIC) logger(LOG_DEBUG, _("Got unauthenticated packet from %s (%s)"), n->name, n->hostname);
+		return;
 	}
 
 	/* Decrypt the packet */
 
-	if(myself->cipher) {
+	if(cipher_active(&myself->cipher)) {
 		outpkt = pkt[nextpkt++];
+		outlen = MAXSIZE;
 
-		if(!EVP_DecryptInit_ex(&packet_ctx, NULL, NULL, NULL, NULL)
-				|| !EVP_DecryptUpdate(&packet_ctx, (unsigned char *) &outpkt->seqno, &outlen,
-					(unsigned char *) &inpkt->seqno, inpkt->len)
-				|| !EVP_DecryptFinal_ex(&packet_ctx, (unsigned char *) &outpkt->seqno + outlen, &outpad)) {
-			ifdebug(TRAFFIC) logger(LOG_DEBUG, _("Error decrypting packet from %s (%s): %s"),
-						n->name, n->hostname, ERR_error_string(ERR_get_error(), NULL));
+		if(!cipher_decrypt(&myself->cipher, &inpkt->seqno, inpkt->len, &outpkt->seqno, &outlen, true)) {
+			ifdebug(TRAFFIC) logger(LOG_DEBUG, _("Error decrypting packet from %s (%s)"), n->name, n->hostname);
 			return;
 		}
 		
-		outpkt->len = outlen + outpad;
+		outpkt->len = outlen;
 		inpkt = outpkt;
 	}
 
@@ -283,7 +268,7 @@ static void send_udppacket(node_t *n, vpn_packet_t *origpkt) {
 	int nextpkt = 0;
 	vpn_packet_t *outpkt;
 	int origlen;
-	int outlen, outpad;
+	size_t outlen;
 	vpn_packet_t *copy;
 	static int priority = 0;
 	int origpriority;
@@ -339,28 +324,24 @@ static void send_udppacket(node_t *n, vpn_packet_t *origpkt) {
 
 	/* Encrypt the packet */
 
-	if(n->cipher) {
+	if(cipher_active(&n->cipher)) {
 		outpkt = pkt[nextpkt++];
+		outlen = MAXSIZE;
 
-		if(!EVP_EncryptInit_ex(&n->packet_ctx, NULL, NULL, NULL, NULL)
-				|| !EVP_EncryptUpdate(&n->packet_ctx, (unsigned char *) &outpkt->seqno, &outlen,
-					(unsigned char *) &inpkt->seqno, inpkt->len)
-				|| !EVP_EncryptFinal_ex(&n->packet_ctx, (unsigned char *) &outpkt->seqno + outlen, &outpad)) {
-			ifdebug(TRAFFIC) logger(LOG_ERR, _("Error while encrypting packet to %s (%s): %s"),
-						n->name, n->hostname, ERR_error_string(ERR_get_error(), NULL));
+		if(!cipher_encrypt(&n->cipher, &inpkt->seqno, inpkt->len, &outpkt->seqno, &outlen, true)) {
+			ifdebug(TRAFFIC) logger(LOG_ERR, _("Error while encrypting packet to %s (%s)"), n->name, n->hostname);
 			goto end;
 		}
 
-		outpkt->len = outlen + outpad;
+		outpkt->len = outlen;
 		inpkt = outpkt;
 	}
 
 	/* Add the message authentication code */
 
-	if(n->digest && n->maclength) {
-		HMAC(n->digest, n->key, n->keylength, (unsigned char *) &inpkt->seqno,
-			 inpkt->len, (unsigned char *) &inpkt->seqno + inpkt->len, NULL);
-		inpkt->len += n->maclength;
+	if(digest_active(&n->digest)) {
+		digest_create(&n->digest, &inpkt->seqno, inpkt->len, &inpkt->seqno + inpkt->len);
+		inpkt->len += digest_length(&n->digest);
 	}
 
 	/* Determine which socket we have to use */
diff --git a/src/net_setup.c b/src/net_setup.c
index b8fb4f02..033bf376 100644
--- a/src/net_setup.c
+++ b/src/net_setup.c
@@ -22,17 +22,13 @@
 
 #include "system.h"
 
-#include <openssl/pem.h>
-#include <openssl/rsa.h>
-#include <openssl/rand.h>
-#include <openssl/err.h>
-#include <openssl/evp.h>
-
 #include "splay_tree.h"
+#include "cipher.h"
 #include "conf.h"
 #include "connection.h"
 #include "control.h"
 #include "device.h"
+#include "digest.h"
 #include "graph.h"
 #include "logger.h"
 #include "net.h"
@@ -40,6 +36,7 @@
 #include "process.h"
 #include "protocol.h"
 #include "route.h"
+#include "rsa.h"
 #include "subnet.h"
 #include "utils.h"
 #include "xalloc.h"
@@ -50,125 +47,66 @@ static struct event device_ev;
 bool read_rsa_public_key(connection_t *c) {
 	FILE *fp;
 	char *fname;
-	char *key;
+	char *n;
+	bool result;
 
 	cp();
 
-	if(!c->rsa_key) {
-		c->rsa_key = RSA_new();
-//		RSA_blinding_on(c->rsa_key, NULL);
-	}
-
 	/* First, check for simple PublicKey statement */
 
-	if(get_config_string(lookup_config(c->config_tree, "PublicKey"), &key)) {
-		BN_hex2bn(&c->rsa_key->n, key);
-		BN_hex2bn(&c->rsa_key->e, "FFFF");
-		free(key);
-		return true;
+	if(get_config_string(lookup_config(c->config_tree, "PublicKey"), &n)) {
+		result = rsa_set_hex_public_key(&c->rsa, n, "FFFF");
+		free(n);
+		return result;
 	}
 
 	/* 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(!get_config_string(lookup_config(c->config_tree, "PublicKeyFile"), &fname))
+		asprintf(&fname, "%s/hosts/%s", confbase, c->name);
 
-		/* 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;
-		}
+	fp = fopen(fname, "r");
 
-		logger(LOG_ERR, _("Reading RSA public key file `%s' failed: %s"),
+	if(!fp) {
+		logger(LOG_ERR, _("Error reading RSA public key file `%s': %s"),
 			   fname, strerror(errno));
+		free(fname);
 		return false;
 	}
 
-	/* Else, check if a harnessed public key is in the config file */
-
-	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);
-	}
-
-	free(fname);
-
-	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);
-	}
+	result = rsa_read_pem_public_key(&c->rsa, fp);
+	fclose(fp);
 
+	if(!result) 
+		logger(LOG_ERR, _("Reading RSA public key file `%s' failed: %s"), fname, strerror(errno));
 	free(fname);
-
-	if(c->rsa_key)
-		return true;
-
-	logger(LOG_ERR, _("No public key for %s specified!"), c->name);
-
-	return false;
+	return result;
 }
 
-bool read_rsa_private_key(void) {
+bool read_rsa_private_key() {
 	FILE *fp;
-	char *fname, *key, *pubkey;
-	struct stat s;
+	char *fname;
+	char *n, *d;
+	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)) {
+	/* First, check for simple PrivateKey statement */
+
+	if(get_config_string(lookup_config(config_tree, "PrivateKey"), &d)) {
+		if(!get_config_string(lookup_config(myself->connection->config_tree, "PublicKey"), &n)) {
 			logger(LOG_ERR, _("PrivateKey used but no PublicKey found!"));
+			free(d);
 			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);
+		result = rsa_set_hex_private_key(&myself->connection->rsa, n, "FFFF", d);
+		free(n);
+		free(d);
 		return true;
 	}
 
+	/* Else, check for PrivateKeyFile statement and read it */
+
 	if(!get_config_string(lookup_config(config_tree, "PrivateKeyFile"), &fname))
 		asprintf(&fname, "%s/rsa_key.priv", confbase);
 
@@ -182,9 +120,10 @@ 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'"),
-				fname, strerror(errno));
+		logger(LOG_ERR, _("Could not stat RSA private key file `%s': %s'"), fname, strerror(errno));
 		free(fname);
 		return false;
 	}
@@ -193,18 +132,13 @@ 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 = rsa_read_pem_private_key(&myself->connection->rsa, fp);
 	fclose(fp);
 
-	if(!myself->connection->rsa_key) {
-		logger(LOG_ERR, _("Reading RSA private key file `%s' failed: %s"),
-			   fname, strerror(errno));
-		free(fname);
-		return false;
-	}
-
+	if(!result) 
+		logger(LOG_ERR, _("Reading RSA private key file `%s' failed: %s"), fname, strerror(errno));
 	free(fname);
-	return true;
+	return result;
 }
 
 static struct event keyexpire_event;
@@ -214,10 +148,14 @@ static void keyexpire_handler(int fd, short events, void *data) {
 }
 
 void regenerate_key() {
-	RAND_pseudo_bytes((unsigned char *)myself->key, myself->keylength);
+	ifdebug(STATUS) logger(LOG_INFO, _("Regenerating symmetric key"));
+
+	if(!cipher_regenerate_key(&myself->cipher, true)) {
+		logger(LOG_ERR, _("Error regenerating key!"));
+		abort();
+	}
 
 	if(timeout_initialized(&keyexpire_event)) {
-		ifdebug(STATUS) logger(LOG_INFO, _("Regenerating symmetric key"));
 		event_del(&keyexpire_event);
 		send_key_changed(broadcast, myself);
 	} else {
@@ -225,16 +163,6 @@ void regenerate_key() {
 	}
 
 	event_add(&keyexpire_event, &(struct timeval){keylifetime, 0});
-
-	if(myself->cipher) {
-		EVP_CIPHER_CTX_init(&packet_ctx);
-		if(!EVP_DecryptInit_ex(&packet_ctx, myself->cipher, NULL, (unsigned char *)myself->key, (unsigned char *)myself->key + myself->cipher->key_len)) {
-			logger(LOG_ERR, _("Error during initialisation of cipher for %s (%s): %s"),
-					myself->name, myself->hostname, ERR_error_string(ERR_get_error(), NULL));
-			abort();
-		}
-
-	}
 }
 
 /*
@@ -373,73 +301,44 @@ bool setup_myself(void) {
 
 	/* Generate packet encryption key */
 
-	if(get_config_string
-	   (lookup_config(myself->connection->config_tree, "Cipher"), &cipher)) {
-		if(!strcasecmp(cipher, "none")) {
-			myself->cipher = NULL;
-		} else {
-			myself->cipher = EVP_get_cipherbyname(cipher);
-
-			if(!myself->cipher) {
-				logger(LOG_ERR, _("Unrecognized cipher type!"));
-				return false;
-			}
-		}
-	} else
-		myself->cipher = EVP_bf_cbc();
-
-	if(myself->cipher)
-		myself->keylength = myself->cipher->key_len + myself->cipher->iv_len;
-	else
-		myself->keylength = 1;
-
-	myself->connection->outcipher = EVP_bf_ofb();
+	if(!get_config_string(lookup_config(myself->connection->config_tree, "Cipher"), &cipher))
+		cipher = xstrdup("blowfish");
 
-	myself->key = xmalloc(myself->keylength);
+	if(!cipher_open_by_name(&myself->cipher, cipher)) {
+		logger(LOG_ERR, _("Unrecognized cipher type!"));
+		return false;
+	}
 
 	if(!get_config_int(lookup_config(config_tree, "KeyExpire"), &keylifetime))
 		keylifetime = 3600;
 
 	regenerate_key();
+
 	/* Check if we want to use message authentication codes... */
 
-	if(get_config_string
-	   (lookup_config(myself->connection->config_tree, "Digest"), &digest)) {
-		if(!strcasecmp(digest, "none")) {
-			myself->digest = NULL;
-		} else {
-			myself->digest = EVP_get_digestbyname(digest);
-
-			if(!myself->digest) {
-				logger(LOG_ERR, _("Unrecognized digest type!"));
-				return false;
-			}
-		}
-	} else
-		myself->digest = EVP_sha1();
-
-	myself->connection->outdigest = EVP_sha1();
-
-	if(get_config_int(lookup_config(myself->connection->config_tree, "MACLength"),
-		&myself->maclength)) {
-		if(myself->digest) {
-			if(myself->maclength > myself->digest->md_size) {
-				logger(LOG_ERR, _("MAC length exceeds size of digest!"));
-				return false;
-			} else if(myself->maclength < 0) {
-				logger(LOG_ERR, _("Bogus MAC length!"));
-				return false;
-			}
-		}
-	} else
-		myself->maclength = 4;
+	if(!get_config_string(lookup_config(myself->connection->config_tree, "Digest"), &digest))
+		digest = xstrdup("sha1");
 
-	myself->connection->outmaclength = 0;
+	if(!digest_open_by_name(&myself->digest, digest)) {
+		logger(LOG_ERR, _("Unrecognized digest type!"));
+		return false;
+	}
+
+	if(!get_config_int(lookup_config(myself->connection->config_tree, "MACLength"), &myself->maclength))
+
+	if(digest_active(&myself->digest)) {
+		if(myself->maclength > digest_length(&myself->digest)) {
+			logger(LOG_ERR, _("MAC length exceeds size of digest!"));
+			return false;
+		} else if(myself->maclength < 0) {
+			logger(LOG_ERR, _("Bogus MAC length!"));
+			return false;
+		}
+	}
 
 	/* Compression */
 
-	if(get_config_int(lookup_config(myself->connection->config_tree, "Compression"),
-		&myself->compression)) {
+	if(get_config_int(lookup_config(myself->connection->config_tree, "Compression"), &myself->compression)) {
 		if(myself->compression < 0 || myself->compression > 11) {
 			logger(LOG_ERR, _("Bogus compression level!"));
 			return false;
@@ -463,8 +362,8 @@ bool setup_myself(void) {
 	if(!setup_device())
 		return false;
 
-	event_set(&device_ev, device_fd, EV_READ|EV_PERSIST,
-			  handle_device_data, NULL);
+	event_set(&device_ev, device_fd, EV_READ|EV_PERSIST, handle_device_data, NULL);
+
 	if (event_add(&device_ev, NULL) < 0) {
 		logger(LOG_ERR, _("event_add failed: %s"), strerror(errno));
 		close_device();
diff --git a/src/node.c b/src/node.c
index 0960ca76..99bbb6db 100644
--- a/src/node.c
+++ b/src/node.c
@@ -74,7 +74,6 @@ node_t *new_node(void) {
 	n->subnet_tree = new_subnet_tree();
 	n->edge_tree = new_edge_tree();
 	n->queue = list_alloc((list_action_t) free);
-	EVP_CIPHER_CTX_init(&n->packet_ctx);
 	n->mtu = MTU;
 	n->maxmtu = MTU;
 
@@ -87,9 +86,6 @@ void free_node(node_t *n) {
 	if(n->queue)
 		list_delete_list(n->queue);
 
-	if(n->key)
-		free(n->key);
-
 	if(n->subnet_tree)
 		free_subnet_tree(n->subnet_tree);
 
@@ -98,7 +94,8 @@ void free_node(node_t *n) {
 
 	sockaddrfree(&n->address);
 
-	EVP_CIPHER_CTX_cleanup(&n->packet_ctx);
+	cipher_close(&n->cipher);
+	digest_close(&n->digest);
 
 	event_del(&n->mtuevent);
 	
@@ -169,8 +166,8 @@ int dump_nodes(struct evbuffer *out) {
 	for(node = node_tree->head; node; node = node->next) {
 		n = node->data;
 		if(evbuffer_add_printf(out, _(" %s at %s cipher %d digest %d maclength %d compression %d options %lx status %04x nexthop %s via %s pmtu %d (min %d max %d)\n"),
-			   n->name, n->hostname, n->cipher ? n->cipher->nid : 0,
-			   n->digest ? n->digest->type : 0, n->maclength, n->compression,
+			   n->name, n->hostname, cipher_get_nid(&n->cipher),
+			   digest_get_nid(&n->digest), n->maclength, n->compression,
 			   n->options, *(uint32_t *)&n->status, n->nexthop ? n->nexthop->name : "-",
 			   n->via ? n->via->name : "-", n->mtu, n->minmtu, n->maxmtu) == -1)
 			return errno;
diff --git a/src/node.h b/src/node.h
index 0476cdb0..fee68593 100644
--- a/src/node.h
+++ b/src/node.h
@@ -24,7 +24,9 @@
 #define __TINC_NODE_H__
 
 #include "splay_tree.h"
+#include "cipher.h"
 #include "connection.h"
+#include "digest.h"
 #include "list.h"
 #include "subnet.h"
 
@@ -50,13 +52,9 @@ typedef struct node_t {
 
 	node_status_t status;
 
-	const EVP_CIPHER *cipher;		/* Cipher type for UDP packets */
-	char *key;				/* Cipher key and iv */
-	int keylength;				/* Cipher key and iv length */
-	EVP_CIPHER_CTX packet_ctx;		/* Cipher context */
-	
-	const EVP_MD *digest;			/* Digest type for MAC */
-	int maclength;				/* Length of MAC */
+	cipher_t cipher;                        /* Cipher for UDP packets */
+	digest_t digest;                        /* Digest for UDP packets */	
+	int maclength;				/* Portion of digest to use */
 
 	int compression;			/* Compressionlevel, 0 = no compression */
 
diff --git a/src/protocol_auth.c b/src/protocol_auth.c
index 49dfd281..0471932a 100644
--- a/src/protocol_auth.c
+++ b/src/protocol_auth.c
@@ -22,14 +22,10 @@
 
 #include "system.h"
 
-#include <openssl/sha.h>
-#include <openssl/rand.h>
-#include <openssl/err.h>
-#include <openssl/evp.h>
-
 #include "splay_tree.h"
 #include "conf.h"
 #include "connection.h"
+#include "crypto.h"
 #include "edge.h"
 #include "graph.h"
 #include "logger.h"
@@ -37,6 +33,7 @@
 #include "netutl.h"
 #include "node.h"
 #include "protocol.h"
+#include "rsa.h"
 #include "utils.h"
 #include "xalloc.h"
 
@@ -117,27 +114,22 @@ bool id_h(connection_t *c, char *request) {
 }
 
 bool send_metakey(connection_t *c) {
-	char *buffer;
-	int len;
-	bool x;
+	size_t len = rsa_size(&c->rsa);
+	char key[len];
+	char enckey[len];
+	char hexkey[2 * len + 1];
 
 	cp();
 
-	len = RSA_size(c->rsa_key);
-
-	/* Allocate buffers for the meta key */
-
-	buffer = alloca(2 * len + 1);
+	if(!cipher_open_blowfish_ofb(&c->outcipher))
+		return false;
 	
-	if(!c->outkey)
-		c->outkey = xmalloc(len);
+	if(!digest_open_sha1(&c->outdigest))
+		return false;
 
-	if(!c->outctx)
-		c->outctx = xmalloc_and_zero(sizeof(*c->outctx));
-	cp();
-	/* Copy random data to the buffer */
+	/* Create a random key */
 
-	RAND_pseudo_bytes((unsigned char *)c->outkey, len);
+	randomize(key, len);
 
 	/* The message we send must be smaller than the modulus of the RSA key.
 	   By definition, for a key of k bits, the following formula holds:
@@ -149,13 +141,14 @@ bool send_metakey(connection_t *c) {
 	   This can be done by setting the most significant bit to zero.
 	 */
 
-	c->outkey[0] &= 0x7F;
+	key[0] &= 0x7F;
+
+	cipher_set_key_from_rsa(&c->outcipher, key, len, true);
 
 	ifdebug(SCARY_THINGS) {
-		bin2hex(c->outkey, buffer, len);
-		buffer[len * 2] = '\0';
-		logger(LOG_DEBUG, _("Generated random meta key (unencrypted): %s"),
-			   buffer);
+		bin2hex(key, hexkey, len);
+		hexkey[len * 2] = '\0';
+		logger(LOG_DEBUG, _("Generated random meta key (unencrypted): %s"), hexkey);
 	}
 
 	/* Encrypt the random data
@@ -165,135 +158,78 @@ 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) {
-		logger(LOG_ERR, _("Error during encryption of meta key for %s (%s)"),
-			   c->name, c->hostname);
+	if(!rsa_public_encrypt(&c->rsa, key, len, enckey)) {
+		logger(LOG_ERR, _("Error during encryption of meta key for %s (%s)"), c->name, c->hostname);
 		return false;
 	}
 
 	/* Convert the encrypted random data to a hexadecimal formatted string */
 
-	bin2hex(buffer, buffer, len);
-	buffer[len * 2] = '\0';
+	bin2hex(enckey, hexkey, len);
+	hexkey[len * 2] = '\0';
 
 	/* Send the meta key */
 
-	x = send_request(c, "%d %d %d %d %d %s", METAKEY,
-					 c->outcipher ? c->outcipher->nid : 0,
-					 c->outdigest ? c->outdigest->type : 0, c->outmaclength,
-					 c->outcompression, buffer);
-
-	/* Further outgoing requests are encrypted with the key we just generated */
-
-	if(c->outcipher) {
-		if(!EVP_EncryptInit(c->outctx, c->outcipher,
-					(unsigned char *)c->outkey + len - c->outcipher->key_len,
-					(unsigned char *)c->outkey + len - c->outcipher->key_len -
-					c->outcipher->iv_len)) {
-			logger(LOG_ERR, _("Error during initialisation of cipher for %s (%s): %s"),
-					c->name, c->hostname, ERR_error_string(ERR_get_error(), NULL));
-			return false;
-		}
-
-		c->status.encryptout = true;
-	}
-
-	return x;
+	bool result = send_request(c, "%d %d %d %d %d %s", METAKEY,
+			 cipher_get_nid(&c->outcipher),
+			 digest_get_nid(&c->outdigest), c->outmaclength,
+			 c->outcompression, hexkey);
+	
+	c->status.encryptout = true;
+	return result;
 }
 
 bool metakey_h(connection_t *c, char *request) {
-	char buffer[MAX_STRING_SIZE];
+	char hexkey[MAX_STRING_SIZE];
 	int cipher, digest, maclength, compression;
-	int len;
+	size_t len = rsa_size(&myself->connection->rsa);
+	char enckey[len];
+	char key[len];
 
 	cp();
 
-	if(sscanf(request, "%*d %d %d %d %d " MAX_STRING, &cipher, &digest, &maclength, &compression, buffer) != 5) {
-		logger(LOG_ERR, _("Got bad %s from %s (%s)"), "METAKEY", c->name,
-			   c->hostname);
+	if(sscanf(request, "%*d %d %d %d %d " MAX_STRING, &cipher, &digest, &maclength, &compression, hexkey) != 5) {
+		logger(LOG_ERR, _("Got bad %s from %s (%s)"), "METAKEY", c->name, c->hostname);
 		return false;
 	}
 
-	len = RSA_size(myself->connection->rsa_key);
-
 	/* Check if the length of the meta key is all right */
 
-	if(strlen(buffer) != len * 2) {
+	if(strlen(hexkey) != len * 2) {
 		logger(LOG_ERR, _("Possible intruder %s (%s): %s"), c->name, c->hostname, "wrong keylength");
 		return false;
 	}
 
-	/* Allocate buffers for the meta key */
-
-	if(!c->inkey)
-		c->inkey = xmalloc(len);
-
-	if(!c->inctx)
-		c->inctx = xmalloc_and_zero(sizeof(*c->inctx));
-
 	/* Convert the challenge from hexadecimal back to binary */
 
-	hex2bin(buffer, buffer, len);
+	hex2bin(hexkey, enckey, len);
 
 	/* 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() */
-		logger(LOG_ERR, _("Error during encryption of meta key for %s (%s)"),
-			   c->name, c->hostname);
+	if(!rsa_private_decrypt(&myself->connection->rsa, enckey, len, key)) {
+		logger(LOG_ERR, _("Error during encryption of meta key for %s (%s)"), c->name, c->hostname);
 		return false;
 	}
 
 	ifdebug(SCARY_THINGS) {
-		bin2hex(c->inkey, buffer, len);
-		buffer[len * 2] = '\0';
-		logger(LOG_DEBUG, _("Received random meta key (unencrypted): %s"), buffer);
+		bin2hex(key, hexkey, len);
+		hexkey[len * 2] = '\0';
+		logger(LOG_DEBUG, _("Received random meta key (unencrypted): %s"), hexkey);
 	}
 
-	/* All incoming requests will now be encrypted. */
-
 	/* Check and lookup cipher and digest algorithms */
 
-	if(cipher) {
-		c->incipher = EVP_get_cipherbynid(cipher);
-		
-		if(!c->incipher) {
-			logger(LOG_ERR, _("%s (%s) uses unknown cipher!"), c->name, c->hostname);
-			return false;
-		}
-
-		if(!EVP_DecryptInit(c->inctx, c->incipher,
-					(unsigned char *)c->inkey + len - c->incipher->key_len,
-					(unsigned char *)c->inkey + len - c->incipher->key_len -
-					c->incipher->iv_len)) {
-			logger(LOG_ERR, _("Error during initialisation of cipher from %s (%s): %s"),
-					c->name, c->hostname, ERR_error_string(ERR_get_error(), NULL));
-			return false;
-		}
-
-		c->status.decryptin = true;
-	} else {
-		c->incipher = NULL;
+	if(!cipher_open_by_nid(&c->incipher, cipher) || !cipher_set_key_from_rsa(&c->incipher, key, len, false)) {
+		logger(LOG_ERR, _("Error during initialisation of cipher from %s (%s)"), c->name, c->hostname);
+		return false;
 	}
 
-	c->inmaclength = maclength;
-
-	if(digest) {
-		c->indigest = EVP_get_digestbynid(digest);
-
-		if(!c->indigest) {
-			logger(LOG_ERR, _("Node %s (%s) uses unknown digest!"), c->name, c->hostname);
-			return false;
-		}
-
-		if(c->inmaclength > c->indigest->md_size || c->inmaclength < 0) {
-			logger(LOG_ERR, _("%s (%s) uses bogus MAC length!"), c->name, c->hostname);
-			return false;
-		}
-	} else {
-		c->indigest = NULL;
+	if(!digest_open_by_nid(&c->indigest, digest)) {
+		logger(LOG_ERR, _("Error during initialisation of digest from %s (%s)"), c->name, c->hostname);
+		return false;
 	}
 
-	c->incompression = compression;
+	c->status.decryptin = true;
 
 	c->allow_request = CHALLENGE;
 
@@ -301,25 +237,17 @@ bool metakey_h(connection_t *c, char *request) {
 }
 
 bool send_challenge(connection_t *c) {
-	char *buffer;
-	int len;
+	size_t len = rsa_size(&c->rsa);
+	char buffer[len * 2 + 1];
 
 	cp();
 
-	/* CHECKME: what is most reasonable value for len? */
-
-	len = RSA_size(c->rsa_key);
-
-	/* Allocate buffers for the challenge */
-
-	buffer = alloca(2 * len + 1);
-
 	if(!c->hischallenge)
 		c->hischallenge = xmalloc(len);
 
 	/* Copy random data to the buffer */
 
-	RAND_pseudo_bytes((unsigned char *)c->hischallenge, len);
+	randomize(c->hischallenge, len);
 
 	/* Convert to hex */
 
@@ -333,72 +261,48 @@ bool send_challenge(connection_t *c) {
 
 bool challenge_h(connection_t *c, char *request) {
 	char buffer[MAX_STRING_SIZE];
-	int len;
+	size_t len = rsa_size(&myself->connection->rsa);
+	size_t digestlen = digest_length(&c->outdigest);
+	char digest[digestlen];
 
 	cp();
 
 	if(sscanf(request, "%*d " MAX_STRING, buffer) != 1) {
-		logger(LOG_ERR, _("Got bad %s from %s (%s)"), "CHALLENGE", c->name,
-			   c->hostname);
+		logger(LOG_ERR, _("Got bad %s from %s (%s)"), "CHALLENGE", c->name, c->hostname);
 		return false;
 	}
 
-	len = RSA_size(myself->connection->rsa_key);
-
 	/* Check if the length of the challenge is all right */
 
 	if(strlen(buffer) != len * 2) {
-		logger(LOG_ERR, _("Possible intruder %s (%s): %s"), c->name,
-			   c->hostname, "wrong challenge length");
+		logger(LOG_ERR, _("Possible intruder %s (%s): %s"), c->name, c->hostname, "wrong challenge length");
 		return false;
 	}
 
-	/* Allocate buffers for the challenge */
-
-	if(!c->mychallenge)
-		c->mychallenge = xmalloc(len);
-
 	/* Convert the challenge from hexadecimal back to binary */
 
-	hex2bin(buffer, c->mychallenge, len);
+	hex2bin(buffer, buffer, len);
 
 	c->allow_request = CHAL_REPLY;
 
-	/* Rest is done by send_chal_reply() */
-
-	return send_chal_reply(c);
-}
-
-bool send_chal_reply(connection_t *c) {
-	char hash[EVP_MAX_MD_SIZE * 2 + 1];
-	EVP_MD_CTX ctx;
-
 	cp();
 
 	/* 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_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));
-		return false;
-	}
+	digest_create(&c->indigest, buffer, len, digest);
 
 	/* Convert the hash to a hexadecimal formatted string */
 
-	bin2hex(hash, hash, c->indigest->md_size);
-	hash[c->indigest->md_size * 2] = '\0';
+	bin2hex(digest, buffer, digestlen);
+	buffer[digestlen * 2] = '\0';
 
 	/* Send the reply */
 
-	return send_request(c, "%d %s", CHAL_REPLY, hash);
+	return send_request(c, "%d %s", CHAL_REPLY, buffer);
 }
 
 bool chal_reply_h(connection_t *c, char *request) {
 	char hishash[MAX_STRING_SIZE];
-	char myhash[EVP_MAX_MD_SIZE];
-	EVP_MD_CTX ctx;
 
 	cp();
 
@@ -410,38 +314,19 @@ bool chal_reply_h(connection_t *c, char *request) {
 
 	/* Check if the length of the hash is all right */
 
-	if(strlen(hishash) != c->outdigest->md_size * 2) {
-		logger(LOG_ERR, _("Possible intruder %s (%s): %s"), c->name,
-			   c->hostname, _("wrong challenge reply length"));
+	if(strlen(hishash) != digest_length(&c->outdigest) * 2) {
+		logger(LOG_ERR, _("Possible intruder %s (%s): %s"), c->name, c->hostname, _("wrong challenge reply length"));
 		return false;
 	}
 
 	/* Convert the hash to binary format */
 
-	hex2bin(hishash, hishash, c->outdigest->md_size);
-
-	/* 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_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));
-		return false;
-	}
-
-	/* Verify the incoming hash with the calculated hash */
+	hex2bin(hishash, hishash, digest_length(&c->outdigest));
 
-	if(memcmp(hishash, myhash, c->outdigest->md_size)) {
-		logger(LOG_ERR, _("Possible intruder %s (%s): %s"), c->name,
-			   c->hostname, _("wrong challenge reply"));
-
-		ifdebug(SCARY_THINGS) {
-			bin2hex(myhash, hishash, SHA_DIGEST_LENGTH);
-			hishash[SHA_DIGEST_LENGTH * 2] = '\0';
-			logger(LOG_DEBUG, _("Expected challenge reply: %s"), hishash);
-		}
+	/* Verify the hash */
 
+	if(!digest_verify(&c->outdigest, c->hischallenge, rsa_size(&c->rsa), hishash)) {
+		logger(LOG_ERR, _("Possible intruder %s (%s): %s"), c->name, c->hostname, _("wrong challenge reply"));
 		return false;
 	}
 
@@ -449,6 +334,8 @@ bool chal_reply_h(connection_t *c, char *request) {
 	   Send an acknowledgement with the rest of the information needed.
 	 */
 
+	free(c->hischallenge);
+	c->hischallenge = NULL;
 	c->allow_request = ACK;
 
 	return send_ack(c);
diff --git a/src/protocol_key.c b/src/protocol_key.c
index 05bc97ba..52666d99 100644
--- a/src/protocol_key.c
+++ b/src/protocol_key.c
@@ -22,10 +22,8 @@
 
 #include "system.h"
 
-#include <openssl/evp.h>
-#include <openssl/err.h>
-
 #include "splay_tree.h"
+#include "cipher.h"
 #include "connection.h"
 #include "logger.h"
 #include "net.h"
@@ -35,7 +33,7 @@
 #include "utils.h"
 #include "xalloc.h"
 
-bool mykeyused = false;
+static bool mykeyused = false;
 
 bool send_key_changed(connection_t *c, const node_t *n) {
 	cp();
@@ -137,18 +135,19 @@ bool req_key_h(connection_t *c, char *request) {
 }
 
 bool send_ans_key(connection_t *c, const node_t *from, const node_t *to) {
-	char *key;
+	size_t keylen = cipher_keylength(&from->cipher);
+	char key[keylen * 2 + 1];
 
 	cp();
 
-	key = alloca(2 * from->keylength + 1);
-	bin2hex(from->key, key, from->keylength);
-	key[from->keylength * 2] = '\0';
+	cipher_get_key(&from->cipher, key);
+	bin2hex(key, key, keylen);
+	key[keylen * 2] = '\0';
 
 	return send_request(c, "%d %s %s %s %d %d %d %d", ANS_KEY,
 						from->name, to->name, key,
-						from->cipher ? from->cipher->nid : 0,
-						from->digest ? from->digest->type : 0, from->maclength,
+						cipher_get_nid(&from->cipher),
+						digest_get_nid(&from->digest), from->maclength,
 						from->compression);
 }
 
@@ -194,58 +193,28 @@ bool ans_key_h(connection_t *c, char *request) {
 		return send_request(to->nexthop->connection, "%s", request);
 	}
 
-	/* Update our copy of the origin's packet key */
-
-	if(from->key)
-		free(from->key);
-
-	from->key = xstrdup(key);
-	from->keylength = strlen(key) / 2;
-	hex2bin(from->key, from->key, from->keylength);
-	from->key[from->keylength] = '\0';
-
-	from->status.validkey = true;
-	from->status.waitingforkey = false;
-	from->sent_seqno = 0;
-
 	/* Check and lookup cipher and digest algorithms */
 
-	if(cipher) {
-		from->cipher = EVP_get_cipherbynid(cipher);
-
-		if(!from->cipher) {
-			logger(LOG_ERR, _("Node %s (%s) uses unknown cipher!"), from->name,
-				   from->hostname);
-			return false;
-		}
+	if(!cipher_open_by_nid(&from->cipher, cipher)) {
+		logger(LOG_ERR, _("Node %s (%s) uses unknown cipher!"), from->name, from->hostname);
+		return false;
+	}
 
-		if(from->keylength != from->cipher->key_len + from->cipher->iv_len) {
-			logger(LOG_ERR, _("Node %s (%s) uses wrong keylength!"), from->name,
-				   from->hostname);
-			return false;
-		}
-	} else {
-		from->cipher = NULL;
+	if(strlen(key) / 2 != cipher_keylength(&from->cipher)) {
+		logger(LOG_ERR, _("Node %s (%s) uses wrong keylength!"), from->name, from->hostname);
+		return false;
 	}
 
 	from->maclength = maclength;
 
-	if(digest) {
-		from->digest = EVP_get_digestbynid(digest);
-
-		if(!from->digest) {
-			logger(LOG_ERR, _("Node %s (%s) uses unknown digest!"), from->name,
-				   from->hostname);
-			return false;
-		}
+	if(!digest_open_by_nid(&from->digest, digest)) {
+		logger(LOG_ERR, _("Node %s (%s) uses unknown digest!"), from->name, from->hostname);
+		return false;
+	}
 
-		if(from->maclength > from->digest->md_size || from->maclength < 0) {
-			logger(LOG_ERR, _("Node %s (%s) uses bogus MAC length!"),
-				   from->name, from->hostname);
-			return false;
-		}
-	} else {
-		from->digest = NULL;
+	if(from->maclength > digest_length(&from->digest) || from->maclength < 0) {
+		logger(LOG_ERR, _("Node %s (%s) uses bogus MAC length!"), from->name, from->hostname);
+		return false;
 	}
 
 	if(compression < 0 || compression > 11) {
@@ -255,12 +224,14 @@ bool ans_key_h(connection_t *c, char *request) {
 	
 	from->compression = compression;
 
-	if(from->cipher)
-		if(!EVP_EncryptInit_ex(&from->packet_ctx, from->cipher, NULL, (unsigned char *)from->key, (unsigned char *)from->key + from->cipher->key_len)) {
-			logger(LOG_ERR, _("Error during initialisation of key from %s (%s): %s"),
-					from->name, from->hostname, ERR_error_string(ERR_get_error(), NULL));
-			return false;
-		}
+	/* Update our copy of the origin's packet key */
+
+	hex2bin(key, key, cipher_keylength(&from->cipher));
+	cipher_set_key(&from->cipher, key, false);
+
+	from->status.validkey = true;
+	from->status.waitingforkey = false;
+	from->sent_seqno = 0;
 
 	if(from->options & OPTION_PMTU_DISCOVERY && !from->mtuprobes)
 		send_mtu_probe(from);
diff --git a/src/tincd.c b/src/tincd.c
index 20443101..0f78e45a 100644
--- a/src/tincd.c
+++ b/src/tincd.c
@@ -31,18 +31,13 @@
 #include <sys/mman.h>
 #endif
 
-#include <openssl/rand.h>
-#include <openssl/rsa.h>
-#include <openssl/pem.h>
-#include <openssl/evp.h>
-#include <openssl/engine.h>
-
 #include LZO1X_H
 
 #include <getopt.h>
 
 #include "conf.h"
 #include "control.h"
+#include "crypto.h"
 #include "device.h"
 #include "logger.h"
 #include "net.h"
@@ -295,12 +290,7 @@ int main(int argc, char **argv)
 	/* Slllluuuuuuurrrrp! */
 
 	srand(time(NULL));
-	RAND_load_file("/dev/urandom", 1024);
-
-	ENGINE_load_builtin_engines();
-	ENGINE_register_all_complete();
-
-	OpenSSL_add_all_algorithms();
+	crypto_init();
 
 	if(!read_server_config())
 		return 1;
@@ -353,7 +343,7 @@ end:
 	exit_control();
 #endif
 
-	EVP_cleanup();
-	
+	crypto_exit();
+
 	return status;
 }