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-rw-r--r--include/crypto/internal/blockhash.h52
1 files changed, 52 insertions, 0 deletions
diff --git a/include/crypto/internal/blockhash.h b/include/crypto/internal/blockhash.h
new file mode 100644
index 000000000000..52d9d4c82493
--- /dev/null
+++ b/include/crypto/internal/blockhash.h
@@ -0,0 +1,52 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Handle partial blocks for block hash.
+ *
+ * Copyright (c) 2015 Linaro Ltd <ard.biesheuvel@linaro.org>
+ * Copyright (c) 2025 Herbert Xu <herbert@gondor.apana.org.au>
+ */
+
+#ifndef _CRYPTO_INTERNAL_BLOCKHASH_H
+#define _CRYPTO_INTERNAL_BLOCKHASH_H
+
+#include <linux/string.h>
+#include <linux/types.h>
+
+#define BLOCK_HASH_UPDATE_BASE(block_fn, state, src, nbytes, bs, dv, \
+ buf, buflen) \
+ ({ \
+ typeof(block_fn) *_block_fn = &(block_fn); \
+ typeof(state + 0) _state = (state); \
+ unsigned int _buflen = (buflen); \
+ size_t _nbytes = (nbytes); \
+ unsigned int _bs = (bs); \
+ const u8 *_src = (src); \
+ u8 *_buf = (buf); \
+ while ((_buflen + _nbytes) >= _bs) { \
+ const u8 *data = _src; \
+ size_t len = _nbytes; \
+ size_t blocks; \
+ int remain; \
+ if (_buflen) { \
+ remain = _bs - _buflen; \
+ memcpy(_buf + _buflen, _src, remain); \
+ data = _buf; \
+ len = _bs; \
+ } \
+ remain = len % bs; \
+ blocks = (len - remain) / (dv); \
+ (*_block_fn)(_state, data, blocks); \
+ _src += len - remain - _buflen; \
+ _nbytes -= len - remain - _buflen; \
+ _buflen = 0; \
+ } \
+ memcpy(_buf + _buflen, _src, _nbytes); \
+ _buflen += _nbytes; \
+ })
+
+#define BLOCK_HASH_UPDATE(block, state, src, nbytes, bs, buf, buflen) \
+ BLOCK_HASH_UPDATE_BASE(block, state, src, nbytes, bs, 1, buf, buflen)
+#define BLOCK_HASH_UPDATE_BLOCKS(block, state, src, nbytes, bs, buf, buflen) \
+ BLOCK_HASH_UPDATE_BASE(block, state, src, nbytes, bs, bs, buf, buflen)
+
+#endif /* _CRYPTO_INTERNAL_BLOCKHASH_H */