Use a generic AF_ALG wrapper for common operations

src/libstrongswan/plugins/af_alg/Makefile.am

@@ -11,6 +11,7 @@ endif
 
 libstrongswan_af_alg_la_SOURCES = \
 	af_alg_plugin.h af_alg_plugin.c \
+	af_alg_ops.h af_alg_ops.c \
 	af_alg_hasher.h af_alg_hasher.c \
 	af_alg_signer.h af_alg_signer.c \
 	af_alg_crypter.h af_alg_crypter.c

src/libstrongswan/plugins/af_alg/af_alg_ops.c

@@ -0,0 +1,221 @@
+/*
+ * Copyright (C) 2010 Martin Willi
+ * Copyright (C) 2010 revosec AG
+ *
+ * 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.  See <http://www.fsf.org/copyleft/gpl.txt>.
+ *
+ * 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.
+ */
+
+#include "af_alg_ops.h"
+
+#include <unistd.h>
+#include <errno.h>
+#include <linux/socket.h>
+
+#include <debug.h>
+
+typedef struct private_af_alg_ops_t private_af_alg_ops_t;
+
+/**
+ * Private data of an af_alg_ops_t object.
+ */
+struct private_af_alg_ops_t {
+
+	/**
+	 * Public af_alg_ops_t interface.
+	 */
+	af_alg_ops_t public;
+
+	/**
+	 * Transform FD
+	 */
+	int tfm;
+
+	/**
+	 * Operation FD
+	 */
+	int op;
+};
+
+METHOD(af_alg_ops_t, reset, void,
+	private_af_alg_ops_t *this)
+{
+	if (this->op != -1)
+	{
+		close(this->op);
+		this->op = -1;
+	}
+}
+
+METHOD(af_alg_ops_t, hash, void,
+	private_af_alg_ops_t *this, chunk_t data, char *out, size_t outlen)
+{
+	ssize_t len;
+
+	while (this->op == -1)
+	{
+		this->op = accept(this->tfm, NULL, 0);
+		if (this->op == -1)
+		{
+			DBG1(DBG_LIB, "opening AF_ALG hasher failed: %s", strerror(errno));
+			sleep(1);
+		}
+	}
+	do
+	{
+		len = send(this->op, data.ptr, data.len, out ? 0 : MSG_MORE);
+		if (len == -1)
+		{
+			DBG1(DBG_LIB, "writing to AF_ALG hasher failed: %s", strerror(errno));
+			sleep(1);
+		}
+		else
+		{
+			data = chunk_skip(data, len);
+		}
+	}
+	while (data.len);
+
+	if (out)
+	{
+		while (read(this->op, out, outlen) != outlen)
+		{
+			DBG1(DBG_LIB, "reading AF_ALG hasher failed: %s", strerror(errno));
+			sleep(1);
+		}
+		reset(this);
+	}
+}
+
+METHOD(af_alg_ops_t, crypt, void,
+	private_af_alg_ops_t *this, u_int32_t type, chunk_t iv, chunk_t data,
+	char *out)
+{
+	struct msghdr msg = {};
+	struct cmsghdr *cmsg;
+	struct af_alg_iv *ivm;
+	struct iovec iov;
+	char buf[CMSG_SPACE(sizeof(type)) +
+			 CMSG_SPACE(offsetof(struct af_alg_iv, iv) + iv.len)];
+	ssize_t len;
+	int op;
+
+	while ((op = accept(this->tfm, NULL, 0)) == -1)
+	{
+		DBG1(DBG_LIB, "accepting AF_ALG crypter failed: %s", strerror(errno));
+		sleep(1);
+	}
+
+	memset(buf, 0, sizeof(buf));
+
+	msg.msg_control = buf;
+	msg.msg_controllen = sizeof(buf);
+
+	cmsg = CMSG_FIRSTHDR(&msg);
+	cmsg->cmsg_level = SOL_ALG;
+	cmsg->cmsg_type = ALG_SET_OP;
+	cmsg->cmsg_len = CMSG_LEN(sizeof(type));
+	*(u_int32_t*)CMSG_DATA(cmsg) = type;
+
+	cmsg = CMSG_NXTHDR(&msg, cmsg);
+	cmsg->cmsg_level = SOL_ALG;
+	cmsg->cmsg_type = ALG_SET_IV;
+	cmsg->cmsg_len = CMSG_LEN(offsetof(struct af_alg_iv, iv) + iv.len);
+	ivm = (void*)CMSG_DATA(cmsg);
+	ivm->ivlen = iv.len;
+	memcpy(ivm->iv, iv.ptr, iv.len);
+
+	msg.msg_iov = &iov;
+	msg.msg_iovlen = 1;
+
+	while (data.len)
+	{
+		iov.iov_base = data.ptr;
+		iov.iov_len = data.len;
+
+		len = sendmsg(op, &msg, 0);
+		if (len == -1)
+		{
+			DBG1(DBG_LIB, "writing to AF_ALG crypter failed: %s",
+				 strerror(errno));
+			sleep(1);
+			continue;
+		}
+		if (read(op, out, len) != len)
+		{
+			DBG1(DBG_LIB, "reading from AF_ALG crypter failed: %s",
+				 strerror(errno));
+		}
+		data = chunk_skip(data, len);
+		/* no IV for subsequent data chunks */
+		msg.msg_controllen = 0;
+	}
+	close(op);
+}
+
+METHOD(af_alg_ops_t, set_key, void,
+	private_af_alg_ops_t *this, chunk_t key)
+{
+	if (setsockopt(this->tfm, SOL_ALG, ALG_SET_KEY, key.ptr, key.len) == -1)
+	{
+		DBG1(DBG_LIB, "setting AF_ALG key failed: %s", strerror(errno));
+	}
+}
+
+METHOD(af_alg_ops_t, destroy, void,
+	private_af_alg_ops_t *this)
+{
+	close(this->tfm);
+	if (this->op != -1)
+	{
+		close(this->op);
+	}
+	free(this);
+}
+
+/**
+ * See header
+ */
+af_alg_ops_t *af_alg_ops_create(char *type, char *alg)
+{
+	private_af_alg_ops_t *this;
+	struct sockaddr_alg sa = {
+		.salg_family = AF_ALG,
+	};
+
+	strncpy(sa.salg_type, type, sizeof(sa.salg_type));
+	strncpy(sa.salg_name, alg, sizeof(sa.salg_name));
+
+	INIT(this,
+		.public = {
+			.hash = _hash,
+			.reset = _reset,
+			.crypt = _crypt,
+			.set_key = _set_key,
+			.destroy = _destroy,
+		},
+		.tfm = socket(AF_ALG, SOCK_SEQPACKET, 0),
+		.op = -1,
+	);
+	if (this->tfm == -1)
+	{
+		DBG1(DBG_LIB, "opening AF_ALG socket failed: %s", strerror(errno));
+		free(this);
+		return NULL;
+	}
+	if (bind(this->tfm, (struct sockaddr*)&sa, sizeof(sa)) == -1)
+	{
+		DBG1(DBG_LIB, "binding AF_ALG socket for '%s' failed: %s",
+			 sa.salg_name, strerror(errno));
+		destroy(this);
+		return NULL;
+	}
+	return &this->public;
+}

src/libstrongswan/plugins/af_alg/af_alg_ops.h

@@ -0,0 +1,90 @@
+/*
+ * Copyright (C) 2010 Martin Willi
+ * Copyright (C) 2010 revosec AG
+ *
+ * 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.  See <http://www.fsf.org/copyleft/gpl.txt>.
+ *
+ * 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.
+ */
+
+/**
+* @defgroup af_alg_ops af_alg_ops
+ * @{ @ingroup af_alg
+ */
+
+#ifndef AF_ALG_OPS_H_
+#define AF_ALG_OPS_H_
+
+#include <library.h>
+
+#include <linux/if_alg.h>
+
+#ifndef AF_ALG
+#define AF_ALG 38
+#endif /* AF_ALG */
+
+#ifndef SOL_ALG
+#define SOL_ALG 279
+#endif /* SOL_ALG */
+
+typedef struct af_alg_ops_t af_alg_ops_t;
+
+/**
+ * Helper to run AF_ALG operations.
+ */
+struct af_alg_ops_t {
+
+	/**
+	 * Hash a chunk of data.
+	 *
+	 * @param data		data to hash
+	 * @param out		buffer to write hash to, NULL for append mode
+	 * @param outlen	number of bytes to read into out
+	 */
+	void (*hash)(af_alg_ops_t *this, chunk_t data, char *out, size_t outlen);
+
+	/**
+	 * Reset hasher state.
+	 */
+	void (*reset)(af_alg_ops_t *this);
+
+	/**
+	 * En-/Decrypt a chunk of data.
+	 *
+	 * @param type		crypto operation (ALG_OP_DECRYPT/ALG_OP_ENCRYPT)
+	 * @param iv		iv to use
+	 * @param data		data to encrypt/decrypt
+	 * @param out		buffer write processed data to
+	 */
+	void (*crypt)(af_alg_ops_t *this, u_int32_t type, chunk_t iv, chunk_t data,
+				  char *out);
+
+	/**
+	 * Set the key for en-/decryption or HMAC/XCBC operations.
+	 *
+	 * @param key		key to set for transform
+	 */
+	void (*set_key)(af_alg_ops_t *this, chunk_t key);
+
+	/**
+	 * Destroy a af_alg_ops_t.
+	 */
+	void (*destroy)(af_alg_ops_t *this);
+};
+
+/**
+ * Create a af_alg_ops instance.
+ *
+ * @param type			algorithm type (hash, skcipher)
+ * @param alg			algorithm name
+ * @return				TRUE if AF_ALG socket bound successfully
+ */
+af_alg_ops_t *af_alg_ops_create(char *type, char *alg);
+
+#endif /** AF_ALG_OPS_H_ @}*/