ASR_BASE
Change-Id: Icf3719cc0afe3eeb3edc7fa80a2eb5199ca9dda1
diff --git a/marvell/linux/fs/incfs/integrity.c b/marvell/linux/fs/incfs/integrity.c
new file mode 100644
index 0000000..bce319e
--- /dev/null
+++ b/marvell/linux/fs/incfs/integrity.c
@@ -0,0 +1,235 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright 2019 Google LLC
+ */
+#include <crypto/sha.h>
+#include <crypto/hash.h>
+#include <linux/err.h>
+#include <linux/version.h>
+
+#include "integrity.h"
+
+struct incfs_hash_alg *incfs_get_hash_alg(enum incfs_hash_tree_algorithm id)
+{
+ static struct incfs_hash_alg sha256 = {
+ .name = "sha256",
+ .digest_size = SHA256_DIGEST_SIZE,
+ .id = INCFS_HASH_TREE_SHA256
+ };
+ struct incfs_hash_alg *result = NULL;
+ struct crypto_shash *shash;
+
+ if (id == INCFS_HASH_TREE_SHA256) {
+ BUILD_BUG_ON(INCFS_MAX_HASH_SIZE < SHA256_DIGEST_SIZE);
+ result = &sha256;
+ }
+
+ if (result == NULL)
+ return ERR_PTR(-ENOENT);
+
+ /* pairs with cmpxchg_release() below */
+ shash = smp_load_acquire(&result->shash);
+ if (shash)
+ return result;
+
+ shash = crypto_alloc_shash(result->name, 0, 0);
+ if (IS_ERR(shash)) {
+ int err = PTR_ERR(shash);
+
+ pr_err("Can't allocate hash alg %s, error code:%d",
+ result->name, err);
+ return ERR_PTR(err);
+ }
+
+ /* pairs with smp_load_acquire() above */
+ if (cmpxchg_release(&result->shash, NULL, shash) != NULL)
+ crypto_free_shash(shash);
+
+ return result;
+}
+
+struct signature_info {
+ u32 version;
+ enum incfs_hash_tree_algorithm hash_algorithm;
+ u8 log2_blocksize;
+ struct mem_range salt;
+ struct mem_range root_hash;
+};
+
+static bool read_u32(u8 **p, u8 *top, u32 *result)
+{
+ if (*p + sizeof(u32) > top)
+ return false;
+
+ *result = le32_to_cpu(*(__le32 *)*p);
+ *p += sizeof(u32);
+ return true;
+}
+
+static bool read_u8(u8 **p, u8 *top, u8 *result)
+{
+ if (*p + sizeof(u8) > top)
+ return false;
+
+ *result = *(u8 *)*p;
+ *p += sizeof(u8);
+ return true;
+}
+
+static bool read_mem_range(u8 **p, u8 *top, struct mem_range *range)
+{
+ u32 len;
+
+ if (!read_u32(p, top, &len) || *p + len > top)
+ return false;
+
+ range->len = len;
+ range->data = *p;
+ *p += len;
+ return true;
+}
+
+static int incfs_parse_signature(struct mem_range signature,
+ struct signature_info *si)
+{
+ u8 *p = signature.data;
+ u8 *top = signature.data + signature.len;
+ u32 hash_section_size;
+
+ if (signature.len > INCFS_MAX_SIGNATURE_SIZE)
+ return -EINVAL;
+
+ if (!read_u32(&p, top, &si->version) ||
+ si->version != INCFS_SIGNATURE_VERSION)
+ return -EINVAL;
+
+ if (!read_u32(&p, top, &hash_section_size) ||
+ p + hash_section_size > top)
+ return -EINVAL;
+ top = p + hash_section_size;
+
+ if (!read_u32(&p, top, &si->hash_algorithm) ||
+ si->hash_algorithm != INCFS_HASH_TREE_SHA256)
+ return -EINVAL;
+
+ if (!read_u8(&p, top, &si->log2_blocksize) || si->log2_blocksize != 12)
+ return -EINVAL;
+
+ if (!read_mem_range(&p, top, &si->salt))
+ return -EINVAL;
+
+ if (!read_mem_range(&p, top, &si->root_hash))
+ return -EINVAL;
+
+ if (p != top)
+ return -EINVAL;
+
+ return 0;
+}
+
+struct mtree *incfs_alloc_mtree(struct mem_range signature,
+ int data_block_count)
+{
+ int error;
+ struct signature_info si;
+ struct mtree *result = NULL;
+ struct incfs_hash_alg *hash_alg = NULL;
+ int hash_per_block;
+ int lvl;
+ int total_blocks = 0;
+ int blocks_in_level[INCFS_MAX_MTREE_LEVELS];
+ int blocks = data_block_count;
+
+ if (data_block_count <= 0)
+ return ERR_PTR(-EINVAL);
+
+ error = incfs_parse_signature(signature, &si);
+ if (error)
+ return ERR_PTR(error);
+
+ hash_alg = incfs_get_hash_alg(si.hash_algorithm);
+ if (IS_ERR(hash_alg))
+ return ERR_PTR(PTR_ERR(hash_alg));
+
+ if (si.root_hash.len < hash_alg->digest_size)
+ return ERR_PTR(-EINVAL);
+
+ result = kzalloc(sizeof(*result), GFP_NOFS);
+ if (!result)
+ return ERR_PTR(-ENOMEM);
+
+ result->alg = hash_alg;
+ hash_per_block = INCFS_DATA_FILE_BLOCK_SIZE / result->alg->digest_size;
+
+ /* Calculating tree geometry. */
+ /* First pass: calculate how many blocks in each tree level. */
+ for (lvl = 0; blocks > 1; lvl++) {
+ if (lvl >= INCFS_MAX_MTREE_LEVELS) {
+ pr_err("incfs: too much data in mtree");
+ goto err;
+ }
+
+ blocks = (blocks + hash_per_block - 1) / hash_per_block;
+ blocks_in_level[lvl] = blocks;
+ total_blocks += blocks;
+ }
+ result->depth = lvl;
+ result->hash_tree_area_size = total_blocks * INCFS_DATA_FILE_BLOCK_SIZE;
+ if (result->hash_tree_area_size > INCFS_MAX_HASH_AREA_SIZE)
+ goto err;
+
+ blocks = 0;
+ /* Second pass: calculate offset of each level. 0th level goes last. */
+ for (lvl = 0; lvl < result->depth; lvl++) {
+ u32 suboffset;
+
+ blocks += blocks_in_level[lvl];
+ suboffset = (total_blocks - blocks)
+ * INCFS_DATA_FILE_BLOCK_SIZE;
+
+ result->hash_level_suboffset[lvl] = suboffset;
+ }
+
+ /* Root hash is stored separately from the rest of the tree. */
+ memcpy(result->root_hash, si.root_hash.data, hash_alg->digest_size);
+ return result;
+
+err:
+ kfree(result);
+ return ERR_PTR(-E2BIG);
+}
+
+void incfs_free_mtree(struct mtree *tree)
+{
+ kfree(tree);
+}
+
+int incfs_calc_digest(struct incfs_hash_alg *alg, struct mem_range data,
+ struct mem_range digest)
+{
+ SHASH_DESC_ON_STACK(desc, alg->shash);
+
+ if (!alg || !alg->shash || !data.data || !digest.data)
+ return -EFAULT;
+
+ if (alg->digest_size > digest.len)
+ return -EINVAL;
+
+ desc->tfm = alg->shash;
+
+ if (data.len < INCFS_DATA_FILE_BLOCK_SIZE) {
+ int err;
+ void *buf = kzalloc(INCFS_DATA_FILE_BLOCK_SIZE, GFP_NOFS);
+
+ if (!buf)
+ return -ENOMEM;
+
+ memcpy(buf, data.data, data.len);
+ err = crypto_shash_digest(desc, buf, INCFS_DATA_FILE_BLOCK_SIZE,
+ digest.data);
+ kfree(buf);
+ return err;
+ }
+ return crypto_shash_digest(desc, data.data, data.len, digest.data);
+}
+