add cheap SHA1 implementation

1 files changed, 32 insertions, 0 deletions

diff --git a/src/digest/digest.h b/src/digest/digest.h
new file mode 100644
index 0000000..d047b8e
--- /dev/null
+++ b/src/digest/digest.h
@@ -0,0 +1,32 @@
+#ifndef L2SU_DIGEST_H_INCLUDED
+#define L2SU_DIGEST_H_INCLUDED
+
+#include <stdint.h>
+#include <stddef.h>
+
+#define L2_SHA1_BLOCKLEN (64) /* 512 / 8 = 64 */
+#define L2_SHA1_DIGESTLEN (5) /* 160 / 32 = 5 */
+#define L2_SHA1_HEX_STRLEN (40)
+
+typedef struct tag_l2_sha1_state {
+  /* struct members are internal do not use directly */
+  uint32_t state[L2_SHA1_DIGESTLEN];
+  uint8_t chunk[L2_SHA1_BLOCKLEN];
+  size_t nchunk;
+  uint64_t totallen;
+} l2_sha1_state_t;
+
+typedef struct tag_l2_sha1_digest {
+  uint32_t state[L2_SHA1_DIGESTLEN];
+} l2_sha1_digest_t;
+
+void l2_sha1_init(l2_sha1_state_t *st);
+void l2_sha1_update(l2_sha1_state_t *st, const void *data, size_t sz);
+void l2_sha1_finalize(l2_sha1_state_t *st, l2_sha1_digest_t *digest);
+
+int l2_sha1_digest_compare(const l2_sha1_digest_t *d1, const l2_sha1_digest_t *d2);
+void l2_sha1_digest_copy(l2_sha1_digest_t *restrict dest, const l2_sha1_digest_t *restrict src);
+void l2_sha1_digest_to_hex(const l2_sha1_digest_t *dg, char *out);
+int l2_sha1_digest_from_hex(l2_sha1_digest_t *dg, const char *in);
+
+#endif /* include guard */