1 files changed, 114 insertions, 0 deletions
diff --git a/src/linux_alg.c b/src/linux_alg.c
new file mode 100644
index 0000000..70f4752
--- /dev/null
+++ b/src/linux_alg.c
@@ -0,0 +1,114 @@
+/*
+  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 "linux_alg.h"
+
+#include <linux/if_alg.h>
+#include <unistd.h>
+
+
+#ifndef SOL_ALG
+#define SOL_ALG 279
+#endif
+
+
+void fastd_linux_alg_init(fastd_context *ctx) {
+	ctx->algfd_ghash = socket(AF_ALG, SOCK_SEQPACKET, 0);
+	if (ctx->algfd_ghash < 0)
+		goto error_ghash;
+
+	struct sockaddr_alg sa_ghash = {};
+	sa_ghash.salg_family = AF_ALG;
+	strcpy((char*)sa_ghash.salg_type, "hash");
+	strcpy((char*)sa_ghash.salg_name, "ghash");
+	if (bind(ctx->algfd_ghash, (struct sockaddr*)&sa_ghash, sizeof(sa_ghash)) < 0) {
+		close(ctx->algfd_ghash);
+		goto error_ghash;
+	}
+
+	return;
+
+ error_ghash:
+	pr_info(ctx, "no kernel support for GHASH was found, falling back to userspace implementation");
+	ctx->algfd_ghash = -1;
+}
+
+void fastd_linux_alg_close(fastd_context *ctx) {
+	if (ctx->algfd_ghash >= 0)
+		close(ctx->algfd_ghash);
+}
+
+
+int fastd_linux_alg_ghash_init(fastd_context *ctx, uint8_t key[16]) {
+	if (ctx->algfd_ghash < 0)
+		return -1;
+
+	if (setsockopt(ctx->algfd_ghash, SOL_ALG, ALG_SET_KEY, key, 16) < 0) {
+		pr_error_errno(ctx, "fastd_linux_alg_ghash_init: setsockopt");
+		return -1;
+	}
+
+	int ret = accept(ctx->algfd_ghash, NULL, NULL);
+
+	if (ret < 0) {
+		pr_error_errno(ctx, "fastd_linux_alg_ghash_init: accept");
+		return -1;
+	}
+
+	return ret;
+}
+
+bool fastd_linux_alg_ghash(fastd_context *ctx, int fd, uint8_t out[16], const void *data, size_t len) {
+	if (!len)
+		return false;
+
+	const uint8_t *in = data;
+	const uint8_t *end = in+len;
+
+	while (in < end) {
+		int bytes = write(fd, in, end-in);
+		if (bytes < 0) {
+			pr_error_errno(ctx, "fastd_linux_alg_ghash: write");
+			return false;
+		}
+
+		in += bytes;
+	}
+
+	end = out+16;
+
+	while (out < end) {
+		int bytes = read(fd, out, end-out);
+		if (bytes < 0) {
+			pr_error_errno(ctx, "fastd_linux_alg_ghash: read");
+			return false;
+		}
+
+		out += bytes;
+	}
+
+	return true;
+}