crypto/sha256: new module.

[ccan] / ccan / crypto / sha256 / sha256.h

diff --git a/ccan/crypto/sha256/sha256.h b/ccan/crypto/sha256/sha256.h
new file mode 100644 (file)
index 0000000..812091a
--- /dev/null
+++ b/ccan/crypto/sha256/sha256.h
@@ -0,0 +1,153 @@
+#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 {
+               /* Array of chars */
+               unsigned char u8[32];
+               /* Array of uint32_t */
+               uint32_t u32[8];
+       } u;
+};
+
+/**
+ * sha256 - return sha256 of an array of bytes.
+ * @sha256: the sha256 to fill in
+ * @p: array or pointer to first element
+ * @num: the number of elements to hash
+ *
+ * The bytes pointed to by @p is SHA256 hashes into @sha256.  This is
+ * equivalent to sha256_init(), sha256_update() then sha256_done().
+ */
+#define sha256(sha256, p, num) sha256_arr((sha256), (p), (num), sizeof(*(p)))
+
+/**
+ * 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];
+       uint64_t bytes;
+       union {
+               uint32_t u32[8];
+               unsigned char u8[64];
+       } buf;
+#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 staticly 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 }
+#endif
+
+/**
+ * sha256_update - include an array of data in the hash.
+ * @ctx: the sha256_ctx to use
+ * @p: array or pointer to first element
+ * @num: the number of elements to hash
+ *
+ * You can call this multiple times to hash more data, before calling
+ * sha256_done().
+ */
+#define sha256_update(ctx, p, num) \
+       sha256_update_arr((ctx), (p), (num), sizeof(*(p)))
+
+/**
+ * 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);
+
+void sha256_update_arr(struct sha256_ctx *ctx, const void *p,
+                      size_t num, size_t size);
+void sha256_arr(struct sha256 *sha, const void *p, size_t num, size_t size);
+#endif /* CCAN_CRYPTO_SHA256_H */