crypto/shachain: new module

[ccan] / ccan / crypto / shachain / shachain.h

diff --git a/ccan/crypto/shachain/shachain.h b/ccan/crypto/shachain/shachain.h
new file mode 100644 (file)
index 0000000..b0f947e
--- /dev/null
+++ b/ccan/crypto/shachain/shachain.h
@@ -0,0 +1,32 @@
+/* MIT (BSD) license - see LICENSE file for details */
+#ifndef CCAN_CRYPTO_SHACHAIN_H
+#define CCAN_CRYPTO_SHACHAIN_H
+#include "config.h"
+#include <ccan/crypto/sha256/sha256.h>
+#include <stdbool.h>
+#include <stdint.h>
+
+/* Useful for testing. */
+#ifndef shachain_index_t
+#define shachain_index_t uint64_t
+#endif
+
+void shachain_from_seed(const struct sha256 *seed, shachain_index_t index,
+                       struct sha256 *hash);
+
+struct shachain {
+       unsigned int num_valid;
+       struct {
+               shachain_index_t index;
+               struct sha256 hash;
+       } known[sizeof(shachain_index_t) * 8];
+};
+
+void shachain_init(struct shachain *shachain);
+
+void shachain_add_hash(struct shachain *shachain,
+                      shachain_index_t index, const struct sha256 *hash);
+
+bool shachain_get_hash(const struct shachain *shachain,
+                      shachain_index_t index, struct sha256 *hash);
+#endif /* CCAN_CRYPTO_SHACHAIN_H */