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authorMatthias Schiffer <mschiffer@universe-factory.net>2013-11-16 21:52:20 +0100
committerMatthias Schiffer <mschiffer@universe-factory.net>2013-11-16 21:52:20 +0100
commitd4916544299c28c4fb16da6d3306eea0a6d5d79f (patch)
tree159d76c33c29bbf0879a472826072e6755744e91 /src/crypto/mac/ghash/tiny/ghash_tiny.c
parentdb229819366c70bbc45a8dfd657d4214358f61d2 (diff)
downloadfastd-d4916544299c28c4fb16da6d3306eea0a6d5d79f.tar
fastd-d4916544299c28c4fb16da6d3306eea0a6d5d79f.zip
Add "tiny" copy of the builtin ghash implementation
Diffstat (limited to 'src/crypto/mac/ghash/tiny/ghash_tiny.c')
-rw-r--r--src/crypto/mac/ghash/tiny/ghash_tiny.c147
1 files changed, 147 insertions, 0 deletions
diff --git a/src/crypto/mac/ghash/tiny/ghash_tiny.c b/src/crypto/mac/ghash/tiny/ghash_tiny.c
new file mode 100644
index 0000000..f4a06b0
--- /dev/null
+++ b/src/crypto/mac/ghash/tiny/ghash_tiny.c
@@ -0,0 +1,147 @@
+/*
+ Copyright (c) 2012-2013, 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"
+
+
+struct fastd_mac_state {
+ fastd_block128_t H[32][16];
+};
+
+
+static const fastd_block128_t r = { .b = {0xe1} };
+
+
+static inline uint8_t shr(fastd_block128_t *out, const fastd_block128_t *in, int n) {
+ size_t i;
+ uint8_t c = 0;
+
+ for (i = 0; i < sizeof(fastd_block128_t); i++) {
+ uint8_t c2 = in->b[i] << (8-n);
+ out->b[i] = (in->b[i] >> n) | c;
+ c = c2;
+ }
+
+ return (c >> (8-n));
+}
+
+static inline void mulH_a(fastd_block128_t *x, const fastd_mac_state_t *cstate) {
+ fastd_block128_t out = {};
+
+ int i;
+ for (i = 0; i < 16; i++) {
+ xor_a(&out, &cstate->H[2*i][x->b[i]>>4]);
+ xor_a(&out, &cstate->H[2*i+1][x->b[i]&0xf]);
+ }
+
+ *x = out;
+}
+
+
+static fastd_mac_context_t* ghash_initialize(fastd_context_t *ctx UNUSED) {
+ return NULL;
+}
+
+static size_t ghash_key_length(fastd_context_t *ctx UNUSED, const fastd_mac_context_t *cctx UNUSED) {
+ return sizeof(fastd_block128_t);
+}
+
+static fastd_mac_state_t* ghash_init_state(fastd_context_t *ctx UNUSED, const fastd_mac_context_t *mctx UNUSED, const uint8_t *key) {
+ fastd_mac_state_t *state = malloc(sizeof(fastd_mac_state_t));
+
+ fastd_block128_t Hbase[4];
+ fastd_block128_t Rbase[4];
+
+ memcpy(&Hbase[0], key, sizeof(fastd_block128_t));
+ Rbase[0] = r;
+
+ int i;
+ for (i = 1; i < 4; i++) {
+ uint8_t carry = shr(&Hbase[i], &Hbase[i-1], 1);
+ if (carry)
+ xor_a(&Hbase[i], &r);
+
+ shr(&Rbase[i], &Rbase[i-1], 1);
+ }
+
+ fastd_block128_t R[16];
+ memset(state->H, 0, sizeof(state->H));
+ memset(R, 0, sizeof(R));
+
+ for (i = 0; i < 16; i++) {
+ int j;
+ for (j = 0; j < 4; j++) {
+ if (i & (8 >> j)) {
+ xor_a(&state->H[0][i], &Hbase[j]);
+ xor_a(&R[i], &Rbase[j]);
+ }
+ }
+ }
+
+ for (i = 1; i < 32; i++) {
+ int j;
+
+ for (j = 0; j < 16; j++) {
+ uint8_t carry = shr(&state->H[i][j], &state->H[i-1][j], 4);
+ xor_a(&state->H[i][j], &R[carry]);
+ }
+ }
+
+ return state;
+}
+
+static bool ghash_hash(fastd_context_t *ctx UNUSED, const fastd_mac_state_t *state, fastd_block128_t *out, const fastd_block128_t *in, size_t n_blocks) {
+ memset(out, 0, sizeof(fastd_block128_t));
+
+ size_t i;
+ for (i = 0; i < n_blocks; i++) {
+ xor_a(out, &in[i]);
+ mulH_a(out, state);
+ }
+
+ return true;
+}
+
+static void ghash_free_state(fastd_context_t *ctx UNUSED, fastd_mac_state_t *state) {
+ free(state);
+}
+
+static void ghash_free(fastd_context_t *ctx UNUSED, fastd_mac_context_t *mctx UNUSED) {
+}
+
+const fastd_mac_t fastd_mac_ghash_tiny = {
+ .name = "tiny",
+
+ .initialize = ghash_initialize,
+
+ .key_length = ghash_key_length,
+ .init_state = ghash_init_state,
+
+ .hash = ghash_hash,
+
+ .free_state = ghash_free_state,
+ .free = ghash_free,
+};