Huge savedata driver refactor

bdk/libs/nx_savedata/integrity_verification_storage.c

@@ -0,0 +1,155 @@
+/*
+ * Copyright (c) 2019-2020 shchmue
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope 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.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+/*
+ISC License
+
+hactool Copyright (c) 2018, SciresM
+
+Permission to use, copy, modify, and/or distribute this software for any
+purpose with or without fee is hereby granted, provided that the above
+copyright notice and this permission notice appear in all copies.
+
+THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+*/
+
+#include "integrity_verification_storage.h"
+
+#include <gfx_utils.h>
+#include <mem/heap.h>
+#include <sec/se.h>
+#include <utils/types.h>
+
+#include <string.h>
+
+void save_ivfc_storage_init(integrity_verification_storage_ctx_t *ctx, integrity_verification_info_ctx_t *info, substorage *hash_storage, int integrity_check_level) {
+    sector_storage_init(&ctx->base_storage, &info->data, info->block_size);
+    memcpy(&ctx->hash_storage, hash_storage, sizeof(substorage));
+    ctx->integrity_check_level = integrity_check_level;
+    memcpy(ctx->salt, info->salt, sizeof(ctx->salt));
+    ctx->block_validities = calloc(1, sizeof(validity_t) * ctx->base_storage.sector_count);
+}
+
+/* buffer must have size count + 0x20 for salt to by copied in at offset 0. */
+static ALWAYS_INLINE void save_ivfc_storage_do_hash(integrity_verification_storage_ctx_t *ctx, uint8_t *out_hash, void *buffer, uint64_t count) {
+    memcpy(buffer, ctx->salt, sizeof(ctx->salt));
+    se_calc_sha256(out_hash, buffer, count + sizeof(ctx->salt));
+    out_hash[0x1F] |= 0x80;
+}
+
+static ALWAYS_INLINE bool is_empty(const void *buffer, uint64_t count) {
+    bool empty = true;
+    const uint8_t *buf = (const uint8_t *)buffer;
+    for (uint64_t i = 0; i < count; i++) {
+        if (buf[i] != 0) {
+            empty = false;
+            break;
+        }
+    }
+    return empty;
+}
+
+bool save_ivfc_storage_read(integrity_verification_storage_ctx_t *ctx, void *buffer, uint64_t offset, uint64_t count) {
+    if (count > ctx->base_storage.sector_size) {
+        EPRINTF("IVFC read exceeds sector size!");
+        return false;
+    }
+
+    uint64_t block_index = offset / ctx->base_storage.sector_size;
+
+    if (ctx->block_validities[block_index] == VALIDITY_INVALID && ctx->integrity_check_level) {
+        EPRINTF("IVFC hash error!");
+        return false;
+    }
+
+    uint8_t hash_buffer[0x20] = {0};
+    uint64_t hash_pos = block_index * sizeof(hash_buffer);
+
+    if (substorage_read(&ctx->hash_storage, hash_buffer, hash_pos, sizeof(hash_buffer)) != sizeof(hash_buffer))
+        return false;
+
+    if (is_empty(hash_buffer, sizeof(hash_buffer))) {
+        memset(buffer, 0, count);
+        ctx->block_validities[block_index] = VALIDITY_VALID;
+        return true;
+    }
+
+    uint8_t *data_buffer = calloc(1, ctx->base_storage.sector_size + 0x20);
+    if (substorage_read(&ctx->base_storage.base_storage, data_buffer + 0x20, offset - (offset % ctx->base_storage.sector_size), ctx->base_storage.sector_size) != ctx->base_storage.sector_size) {
+        free(data_buffer);
+        return false;
+    }
+
+    if (ctx->integrity_check_level && ctx->block_validities[block_index] != VALIDITY_UNCHECKED) {
+        memcpy(buffer, data_buffer + 0x20 + (offset % ctx->base_storage.sector_size), count);
+        free(data_buffer);
+        return true;
+    }
+
+    uint8_t hash[0x20] = {0};
+    save_ivfc_storage_do_hash(ctx, hash, data_buffer, ctx->base_storage.sector_size);
+    memcpy(buffer, data_buffer + 0x20 + (offset % ctx->base_storage.sector_size), count);
+    free(data_buffer);
+
+    if (memcmp(hash_buffer, hash, sizeof(hash_buffer)) == 0) {
+        ctx->block_validities[block_index] = VALIDITY_VALID;
+    } else {
+        ctx->block_validities[block_index] = VALIDITY_INVALID;
+        if (ctx->integrity_check_level) {
+            EPRINTF("IVFC hash error!");
+            return false;
+        }
+    }
+
+    return true;
+}
+
+bool save_ivfc_storage_write(integrity_verification_storage_ctx_t *ctx, const void *buffer, uint64_t offset, uint64_t count) {
+    uint64_t block_index = offset / ctx->base_storage.sector_size;
+    uint64_t hash_pos = block_index * 0x20;
+
+    uint8_t hash[0x20] = {0};
+    uint8_t *data_buffer = calloc(1, ctx->base_storage.sector_size + 0x20);
+    if (count < ctx->base_storage.sector_size) {
+        if (substorage_read(&ctx->base_storage.base_storage, data_buffer + 0x20, offset - (offset % ctx->base_storage.sector_size), ctx->base_storage.sector_size) != ctx->base_storage.sector_size) {
+            free(data_buffer);
+            return false;
+        }
+    }
+    memcpy(data_buffer + 0x20 + (offset % ctx->base_storage.sector_size), buffer, count);
+
+    if (!is_empty(buffer, count)) {
+        save_ivfc_storage_do_hash(ctx, hash, data_buffer, ctx->base_storage.sector_size);
+    }
+
+    if (substorage_write(&ctx->base_storage.base_storage, data_buffer + 0x20, offset - (offset % ctx->base_storage.sector_size), ctx->base_storage.sector_size) != ctx->base_storage.sector_size) {
+        free(data_buffer);
+        return false;
+    }
+    free(data_buffer);
+    if (substorage_write(&ctx->hash_storage, hash, hash_pos, sizeof(hash)) != sizeof(hash))
+        return false;
+
+    ctx->block_validities[block_index] = VALIDITY_UNCHECKED;
+
+    return true;
+}