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-rw-r--r--crypto/crc32_generic.c132
1 files changed, 132 insertions, 0 deletions
diff --git a/crypto/crc32_generic.c b/crypto/crc32_generic.c
new file mode 100644
index 000000000..a989cb44f
--- /dev/null
+++ b/crypto/crc32_generic.c
@@ -0,0 +1,132 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright 2012 Xyratex Technology Limited
+ */
+
+/*
+ * This is crypto api shash wrappers to crc32_le.
+ */
+
+#include <asm/unaligned.h>
+#include <linux/crc32.h>
+#include <crypto/internal/hash.h>
+#include <linux/init.h>
+#include <linux/module.h>
+#include <linux/string.h>
+#include <linux/kernel.h>
+
+#define CHKSUM_BLOCK_SIZE 1
+#define CHKSUM_DIGEST_SIZE 4
+
+/** No default init with ~0 */
+static int crc32_cra_init(struct crypto_tfm *tfm)
+{
+ u32 *key = crypto_tfm_ctx(tfm);
+
+ *key = 0;
+
+ return 0;
+}
+
+/*
+ * Setting the seed allows arbitrary accumulators and flexible XOR policy
+ * If your algorithm starts with ~0, then XOR with ~0 before you set
+ * the seed.
+ */
+static int crc32_setkey(struct crypto_shash *hash, const u8 *key,
+ unsigned int keylen)
+{
+ u32 *mctx = crypto_shash_ctx(hash);
+
+ if (keylen != sizeof(u32))
+ return -EINVAL;
+ *mctx = get_unaligned_le32(key);
+ return 0;
+}
+
+static int crc32_init(struct shash_desc *desc)
+{
+ u32 *mctx = crypto_shash_ctx(desc->tfm);
+ u32 *crcp = shash_desc_ctx(desc);
+
+ *crcp = *mctx;
+
+ return 0;
+}
+
+static int crc32_update(struct shash_desc *desc, const u8 *data,
+ unsigned int len)
+{
+ u32 *crcp = shash_desc_ctx(desc);
+
+ *crcp = crc32_le(*crcp, data, len);
+ return 0;
+}
+
+/* No final XOR 0xFFFFFFFF, like crc32_le */
+static int __crc32_finup(u32 *crcp, const u8 *data, unsigned int len,
+ u8 *out)
+{
+ put_unaligned_le32(crc32_le(*crcp, data, len), out);
+ return 0;
+}
+
+static int crc32_finup(struct shash_desc *desc, const u8 *data,
+ unsigned int len, u8 *out)
+{
+ return __crc32_finup(shash_desc_ctx(desc), data, len, out);
+}
+
+static int crc32_final(struct shash_desc *desc, u8 *out)
+{
+ u32 *crcp = shash_desc_ctx(desc);
+
+ put_unaligned_le32(*crcp, out);
+ return 0;
+}
+
+static int crc32_digest(struct shash_desc *desc, const u8 *data,
+ unsigned int len, u8 *out)
+{
+ return __crc32_finup(crypto_shash_ctx(desc->tfm), data, len,
+ out);
+}
+static struct shash_alg alg = {
+ .setkey = crc32_setkey,
+ .init = crc32_init,
+ .update = crc32_update,
+ .final = crc32_final,
+ .finup = crc32_finup,
+ .digest = crc32_digest,
+ .descsize = sizeof(u32),
+ .digestsize = CHKSUM_DIGEST_SIZE,
+ .base = {
+ .cra_name = "crc32",
+ .cra_driver_name = "crc32-generic",
+ .cra_priority = 100,
+ .cra_flags = CRYPTO_ALG_OPTIONAL_KEY,
+ .cra_blocksize = CHKSUM_BLOCK_SIZE,
+ .cra_ctxsize = sizeof(u32),
+ .cra_module = THIS_MODULE,
+ .cra_init = crc32_cra_init,
+ }
+};
+
+static int __init crc32_mod_init(void)
+{
+ return crypto_register_shash(&alg);
+}
+
+static void __exit crc32_mod_fini(void)
+{
+ crypto_unregister_shash(&alg);
+}
+
+subsys_initcall(crc32_mod_init);
+module_exit(crc32_mod_fini);
+
+MODULE_AUTHOR("Alexander Boyko <alexander_boyko@xyratex.com>");
+MODULE_DESCRIPTION("CRC32 calculations wrapper for lib/crc32");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS_CRYPTO("crc32");
+MODULE_ALIAS_CRYPTO("crc32-generic");