Nicely encapsulate different crypto algorithm implementations

1 files changed, 259 insertions, 0 deletions

diff --git a/src/crypto_linux.c b/src/crypto_linux.c
new file mode 100644
index 0000000..902170b
--- /dev/null
+++ b/src/crypto_linux.c
@@ -0,0 +1,259 @@
+/*
+  Copyright (c) 2012, Matthias Schiffer <mschiffer@universe-factory.net>
+  All rights reserved.
+
+  Redistribution and use in source and binary forms, with or without
+  modification, are permitted provided that the following conditions are met:
+
+    1. Redistributions of source code must retain the above copyright notice,
+       this list of conditions and the following disclaimer.
+    2. Redistributions in binary form must reproduce the above copyright notice,
+       this list of conditions and the following disclaimer in the documentation
+       and/or other materials provided with the distribution.
+
+  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+  AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+  IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+  DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+  FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+  DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+  SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+  CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+  OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+  OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+*/
+
+
+#include "fastd.h"
+#include "crypto.h"
+
+#include <alloca.h>
+#include <linux/if_alg.h>
+#include <unistd.h>
+
+
+#ifndef SOL_ALG
+#define SOL_ALG 279
+#endif
+
+
+#ifdef USE_CRYPTO_AES128CTR
+#ifdef WITH_CRYPTO_AES128CTR_LINUX
+
+struct _fastd_crypto_aes128ctr_context {
+	int fd;
+};
+
+struct _fastd_crypto_aes128ctr_state {
+	int fd;
+};
+
+static fastd_crypto_aes128ctr_context* aes128ctr_init(fastd_context *ctx) {
+	int fd = socket(AF_ALG, SOCK_SEQPACKET, 0);
+	if (fd < 0)
+		goto error;
+
+	struct sockaddr_alg sa = {};
+	sa.salg_family = AF_ALG;
+	strcpy((char*)sa.salg_type, "skcipher");
+	strcpy((char*)sa.salg_name, "ctr(aes)");
+	if (bind(fd, (struct sockaddr*)&sa, sizeof(sa)) < 0)
+		goto error;
+
+	fastd_crypto_aes128ctr_context *cctx = malloc(sizeof(fastd_crypto_aes128ctr_context));
+	cctx->fd = fd;
+	return cctx;
+
+ error:
+	if (fd >= 0)
+		close(fd);
+
+	pr_error(ctx, "no kernel support for AES-CTR was found");
+	return NULL;
+}
+
+static fastd_crypto_aes128ctr_state* aes128ctr_set_key(fastd_context *ctx, const fastd_crypto_aes128ctr_context *cctx, const fastd_block128 *key) {
+	if (setsockopt(cctx->fd, SOL_ALG, ALG_SET_KEY, key->b, 16) < 0) {
+		pr_error_errno(ctx, "aes128ctr_set_key(linux): setsockopt");
+		return NULL;
+	}
+
+	int fd = accept(cctx->fd, NULL, NULL);
+
+	if (fd < 0) {
+		pr_error_errno(ctx, "aes128ctr_set_key(linux): accept");
+		return NULL;
+	}
+
+	fastd_crypto_aes128ctr_state *cstate = malloc(sizeof(fastd_crypto_aes128ctr_state));
+	cstate->fd = fd;
+
+	return cstate;
+}
+
+static bool aes128ctr_crypt(fastd_context *ctx, const fastd_crypto_aes128ctr_state *cstate, fastd_block128 *out, const fastd_block128 *in, size_t len, const fastd_block128 *iv) {
+	if (!len)
+		return false;
+
+	struct iovec vec = { .iov_base = (void*)in, .iov_len = len };
+
+	static const size_t cmsglen = sizeof(struct cmsghdr)+sizeof(struct af_alg_iv)+16;
+	struct cmsghdr *cmsg = alloca(cmsglen);
+	cmsg->cmsg_len = cmsglen;
+	cmsg->cmsg_level = SOL_ALG;
+	cmsg->cmsg_type = ALG_SET_IV;
+
+	struct af_alg_iv *alg_iv = (void*)CMSG_DATA(cmsg);
+	alg_iv->ivlen = 16;
+	memcpy(alg_iv->iv, iv, 16);
+
+	struct msghdr msg = {
+		.msg_iov = &vec,
+		.msg_iovlen = 1,
+		.msg_control = cmsg,
+		.msg_controllen = cmsglen
+	};
+
+	if (sendmsg(cstate->fd, &msg, 0) < 0) {
+		pr_error_errno(ctx, "aes128ctr_crypt(linux): sendmsg");
+		return false;
+	}
+
+	msg.msg_control = NULL;
+	msg.msg_controllen = 0;
+	vec.iov_base = out;
+
+	if (recvmsg(cstate->fd, &msg, 0) < 0) {
+		pr_error_errno(ctx, "aes128ctr_crypt(linux): recvmsg");
+		return false;
+	}
+
+	return true;
+}
+
+static void aes128ctr_free_state(fastd_context *ctx, fastd_crypto_aes128ctr_state *cstate) {
+	if (cstate) {
+		close(cstate->fd);
+		free(cstate);
+	}
+}
+
+static void aes128ctr_free(fastd_context *ctx, fastd_crypto_aes128ctr_context *cctx) {
+	if (cctx) {
+		close(cctx->fd);
+		free(cctx);
+	}
+}
+
+fastd_crypto_aes128ctr fastd_crypto_aes128ctr_linux = {
+	.name = "linux",
+
+	.init = aes128ctr_init,
+	.set_key = aes128ctr_set_key,
+	.crypt = aes128ctr_crypt,
+
+	.free_state = aes128ctr_free_state,
+	.free = aes128ctr_free,
+};
+
+#endif
+#endif
+
+#ifdef USE_CRYPTO_GHASH
+#ifdef WITH_CRYPTO_GHASH_LINUX
+
+struct _fastd_crypto_ghash_context {
+	int fd;
+};
+
+struct _fastd_crypto_ghash_state {
+	int fd;
+};
+
+static fastd_crypto_ghash_context* ghash_init(fastd_context *ctx) {
+	int fd = socket(AF_ALG, SOCK_SEQPACKET, 0);
+	if (fd < 0)
+		goto error;
+
+	struct sockaddr_alg sa = {};
+	sa.salg_family = AF_ALG;
+	strcpy((char*)sa.salg_type, "hash");
+	strcpy((char*)sa.salg_name, "ghash");
+	if (bind(fd, (struct sockaddr*)&sa, sizeof(sa)) < 0)
+		goto error;
+
+	fastd_crypto_ghash_context *cctx = malloc(sizeof(fastd_crypto_ghash_context));
+	cctx->fd = fd;
+	return cctx;
+
+ error:
+	if (fd >= 0)
+		close(fd);
+
+	pr_error(ctx, "no kernel support for GHASH was found");
+	return NULL;
+}
+
+static fastd_crypto_ghash_state* ghash_set_h(fastd_context *ctx, const fastd_crypto_ghash_context *cctx, const fastd_block128 *h) {
+	if (setsockopt(cctx->fd, SOL_ALG, ALG_SET_KEY, h, 16) < 0) {
+		pr_error_errno(ctx, "ghash_set_h(linux): setsockopt");
+		return NULL;
+	}
+
+	int fd = accept(cctx->fd, NULL, NULL);
+
+	if (fd < 0) {
+		pr_error_errno(ctx, "ghash_set_h(linux): accept");
+		return NULL;
+	}
+
+	fastd_crypto_ghash_state *cstate = malloc(sizeof(fastd_crypto_ghash_state));
+	cstate->fd = fd;
+
+	return cstate;
+}
+
+static bool ghash_hash(fastd_context *ctx, const fastd_crypto_ghash_state *cstate, fastd_block128 *out, const fastd_block128 *in, size_t n_blocks) {
+	if (!n_blocks)
+		return false;
+
+	if (write(cstate->fd, in, n_blocks*16) < 0) {
+		pr_error_errno(ctx, "ghash_hash(linux): write");
+		return false;
+	}
+
+	if (read(cstate->fd, out, 16) < 16) {
+		pr_error_errno(ctx, "ghash_hash(linux): read");
+		return false;
+	}
+
+	return true;
+}
+
+static void ghash_free_state(fastd_context *ctx, fastd_crypto_ghash_state *cstate) {
+	if (cstate) {
+		close(cstate->fd);
+		free(cstate);
+	}
+}
+
+static void ghash_free(fastd_context *ctx, fastd_crypto_ghash_context *cctx) {
+	if (cctx) {
+		close(cctx->fd);
+		free(cctx);
+	}
+}
+
+fastd_crypto_ghash fastd_crypto_ghash_linux = {
+	.name = "linux",
+
+	.init = ghash_init,
+	.set_h = ghash_set_h,
+	.hash = ghash_hash,
+
+	.free_state = ghash_free_state,
+	.free = ghash_free,
+};
+
+#endif
+#endif