damus-c: add bolt11 parser from CLN

We'll need this for our lightning invoice view

Signed-off-by: William Casarin <jb55@jb55.com>

damus-c/sha256.h

@@ -0,0 +1,147 @@
+#ifndef CCAN_CRYPTO_SHA256_H
+#define CCAN_CRYPTO_SHA256_H
+/* BSD-MIT - see LICENSE file for details */
+#include "config.h"
+#include <stdint.h>
+#include <stdlib.h>
+
+/* Uncomment this to use openssl's SHA256 routines (and link with -lcrypto) */
+/*#define CCAN_CRYPTO_SHA256_USE_OPENSSL 1*/
+
+#ifdef CCAN_CRYPTO_SHA256_USE_OPENSSL
+#include <openssl/sha.h>
+#endif
+
+/**
+ * struct sha256 - structure representing a completed SHA256.
+ * @u.u8: an unsigned char array.
+ * @u.u32: a 32-bit integer array.
+ *
+ * Other fields may be added to the union in future.
+ */
+struct sha256 {
+    union {
+        uint32_t u32[8];
+        unsigned char u8[32];
+    } u;
+};
+
+/**
+ * sha256 - return sha256 of an object.
+ * @sha256: the sha256 to fill in
+ * @p: pointer to memory,
+ * @size: the number of bytes pointed to by
+ *
+ * The bytes pointed to by @p is SHA256 hashed into @sha256.  This is
+ * equivalent to sha256_init(), sha256_update() then sha256_done().
+ */
+void sha256(struct sha256 *sha, const void *p, size_t size);
+
+/**
+ * struct sha256_ctx - structure to store running context for sha256
+ */
+struct sha256_ctx {
+#ifdef CCAN_CRYPTO_SHA256_USE_OPENSSL
+    SHA256_CTX c;
+#else
+    uint32_t s[8];
+    union {
+        uint32_t u32[16];
+        unsigned char u8[64];
+    } buf;
+    size_t bytes;
+#endif
+};
+
+/**
+ * sha256_init - initialize an SHA256 context.
+ * @ctx: the sha256_ctx to initialize
+ *
+ * This must be called before sha256_update or sha256_done, or
+ * alternately you can assign SHA256_INIT.
+ *
+ * If it was already initialized, this forgets anything which was
+ * hashed before.
+ *
+ * Example:
+ * static void hash_all(const char **arr, struct sha256 *hash)
+ * {
+ *    size_t i;
+ *    struct sha256_ctx ctx;
+ *
+ *    sha256_init(&ctx);
+ *    for (i = 0; arr[i]; i++)
+ *        sha256_update(&ctx, arr[i], strlen(arr[i]));
+ *    sha256_done(&ctx, hash);
+ * }
+ */
+void sha256_init(struct sha256_ctx *ctx);
+
+/**
+ * SHA256_INIT - initializer for an SHA256 context.
+ *
+ * This can be used to statically initialize an SHA256 context (instead
+ * of sha256_init()).
+ *
+ * Example:
+ * static void hash_all(const char **arr, struct sha256 *hash)
+ * {
+ *    size_t i;
+ *    struct sha256_ctx ctx = SHA256_INIT;
+ *
+ *    for (i = 0; arr[i]; i++)
+ *        sha256_update(&ctx, arr[i], strlen(arr[i]));
+ *    sha256_done(&ctx, hash);
+ * }
+ */
+#ifdef CCAN_CRYPTO_SHA256_USE_OPENSSL
+#define SHA256_INIT                            \
+    { { { 0x6a09e667ul, 0xbb67ae85ul, 0x3c6ef372ul, 0xa54ff53aul,    \
+          0x510e527ful, 0x9b05688cul, 0x1f83d9abul, 0x5be0cd19ul }, \
+        0x0, 0x0,                        \
+        { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 },    \
+            0x0, 0x20 } }
+#else
+#define SHA256_INIT                            \
+    { { 0x6a09e667ul, 0xbb67ae85ul, 0x3c6ef372ul, 0xa54ff53aul,    \
+        0x510e527ful, 0x9b05688cul, 0x1f83d9abul, 0x5be0cd19ul },    \
+      { { 0 } }, 0 }
+#endif
+
+/**
+ * sha256_update - include some memory in the hash.
+ * @ctx: the sha256_ctx to use
+ * @p: pointer to memory,
+ * @size: the number of bytes pointed to by
+ *
+ * You can call this multiple times to hash more data, before calling
+ * sha256_done().
+ */
+void sha256_update(struct sha256_ctx *ctx, const void *p, size_t size);
+
+/**
+ * sha256_done - finish SHA256 and return the hash
+ * @ctx: the sha256_ctx to complete
+ * @res: the hash to return.
+ *
+ * Note that @ctx is *destroyed* by this, and must be reinitialized.
+ * To avoid that, pass a copy instead.
+ */
+void sha256_done(struct sha256_ctx *sha256, struct sha256 *res);
+
+/* Add various types to an SHA256 hash */
+void sha256_u8(struct sha256_ctx *ctx, uint8_t v);
+void sha256_u16(struct sha256_ctx *ctx, uint16_t v);
+void sha256_u32(struct sha256_ctx *ctx, uint32_t v);
+void sha256_u64(struct sha256_ctx *ctx, uint64_t v);
+
+/* Add as little-endian */
+void sha256_le16(struct sha256_ctx *ctx, uint16_t v);
+void sha256_le32(struct sha256_ctx *ctx, uint32_t v);
+void sha256_le64(struct sha256_ctx *ctx, uint64_t v);
+
+/* Add as big-endian */
+void sha256_be16(struct sha256_ctx *ctx, uint16_t v);
+void sha256_be32(struct sha256_ctx *ctx, uint32_t v);
+void sha256_be64(struct sha256_ctx *ctx, uint64_t v);
+#endif /* CCAN_CRYPTO_SHA256_H */