1 files changed, 39 insertions, 0 deletions
diff --git a/src/fundamental/sha256.h b/src/fundamental/sha256.h
new file mode 100644
index 0000000..dbb08e3
--- /dev/null
+++ b/src/fundamental/sha256.h
@@ -0,0 +1,39 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+#pragma once
+
+#include <stddef.h>
+#include <stdint.h>
+
+#define SHA256_DIGEST_SIZE 32
+
+struct sha256_ctx {
+        uint32_t H[8];
+
+        union {
+                uint64_t total64;
+#define TOTAL64_low (1 - (__BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__))
+#define TOTAL64_high (__BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__)
+                uint32_t total[2];
+        };
+
+        uint32_t buflen;
+
+        union {
+                uint8_t  buffer[128]; /* NB: always correctly aligned for UINT32.  */
+                uint32_t buffer32[32];
+                uint64_t buffer64[16];
+        };
+};
+
+void sha256_init_ctx(struct sha256_ctx *ctx);
+uint8_t *sha256_finish_ctx(struct sha256_ctx *ctx, uint8_t resbuf[static SHA256_DIGEST_SIZE]);
+void sha256_process_bytes(const void *buffer, size_t len, struct sha256_ctx *ctx);
+
+static inline void sha256_process_bytes_and_size(const void *buffer, size_t len, struct sha256_ctx *ctx) {
+        sha256_process_bytes(&len, sizeof(len), ctx);
+        sha256_process_bytes(buffer, len, ctx);
+}
+
+uint8_t* sha256_direct(const void *buffer, size_t sz, uint8_t result[static SHA256_DIGEST_SIZE]);
+
+#define SHA256_DIRECT(buffer, sz) sha256_direct(buffer, sz, (uint8_t[SHA256_DIGEST_SIZE]) {})