Use HMACs for keeping track of valid back pages, instead of Merkle Tree

Author: archshift

bench/Makefile

@@ -4,22 +4,22 @@ BENCH_FLAGS := -DUSE_FREEMEM -DUSE_PAGING -DUSE_PAGE_HASH -DUSE_PAGE_CRYPTO -D__
 
 .PHONY: benches clean
 
-benches: merkle crypto
+benches: hmac crypto
 
-MODULES := merkle.o sha256.o aes.o bench/bencher.o bench/crypto.o bench/merkle.o
+MODULES := hmac.o sha256.o aes.o bench/bencher.o bench/crypto.o bench/hmac.o
 OBJ_PREFIX := objs/
 
 $(addprefix $(OBJ_PREFIX),$(MODULES)) :: $(OBJ_PREFIX)%.o : ../%.c
 	mkdir -p $(shell dirname $@)
 	$(CC) $(CFLAGS) $(BENCH_FLAGS) -c -o $@ $^
 
-MERKLE_MODULES := merkle.o sha256.o bench/bencher.o bench/merkle.o
-merkle: $(addprefix $(OBJ_PREFIX),$(MERKLE_MODULES))
+HMAC_MODULES := hmac.o sha256.o bench/bencher.o bench/hmac.o
+hmac: $(addprefix $(OBJ_PREFIX),$(HMAC_MODULES))
 	$(CC) $(CFLAGS) $(BENCH_FLAGS) $^ $(LDFLAGS) -o $@
 
 CRYPTO_MODULES := sha256.o aes.o bench/bencher.o bench/crypto.o
 crypto: $(addprefix $(OBJ_PREFIX),$(CRYPTO_MODULES))
 	$(CC) $(CFLAGS) $(BENCH_FLAGS) $^ $(LDFLAGS) -o $@
 
 clean:
-	rm -rf merkle crypto objs/
+	rm -rf hmac crypto objs/

bench/hmac.c

@@ -0,0 +1,65 @@
+#define _GNU_SOURCE
+
+#include <../hmac.h>
+#include <assert.h>
+#include <bencher.h>
+#include <stdint.h>
+#include <stdlib.h>
+#include <string.h>
+#include <sys/mman.h>
+#include <time.h>
+
+#define RAND_BOOK_LEN (4 * 1024 * 1024)
+
+typedef struct bench_ctx {
+  int* rand_book;
+  uint8_t* key;
+  uint8_t* page;
+} bench_ctx_t;
+
+void
+bench_ctx__init(bench_ctx_t* ctx) {
+  ctx->rand_book = (int*)malloc(sizeof(int) * RAND_BOOK_LEN);
+  for (int i = 0; i < RAND_BOOK_LEN; i++) {
+    ctx->rand_book[i] = rand();
+  }
+}
+
+int
+hmac_page__init(void* _ctx) {
+  bench_ctx_t* ctx = (bench_ctx_t*)_ctx;
+  ctx->key         = (uint8_t*)ctx->rand_book + rand() % (RAND_BOOK_LEN - 32);
+  ctx->page        = (uint8_t*)ctx->rand_book + rand() % (RAND_BOOK_LEN - 4096);
+  return 0;
+}
+
+int
+hmac_page__destroy(void* _ctx) {
+  (void)_ctx;
+  return 0;
+}
+
+int
+hmac_page(void* _ctx) {
+  bench_ctx_t* ctx = (bench_ctx_t*)_ctx;
+  uint8_t hash[32];
+  int err = hmac(ctx->page, 4096, ctx->key, 32, hash);
+  __asm__ __volatile__("" ::"r"(hash));
+  return err;
+}
+
+int
+main(int argc, char** argv) {
+  srand(time(NULL));
+  bench_ctx_t ctx = {};
+  bench_ctx__init(&ctx);
+
+  struct bench benches[] = {
+      {.name   = "hmac page",
+       .init   = hmac_page__init,
+       .deinit = hmac_page__destroy,
+       .iter   = hmac_page},
+  };
+  struct bench_opts opts = bench_argp(argc, argv);
+  run_benches(&opts, benches, sizeof(benches) / sizeof(struct bench), &ctx);
+}