1 files changed, 64 insertions, 0 deletions
diff --git a/src/hash/libwebidoidc-hash.c b/src/hash/libwebidoidc-hash.c
new file mode 100644
index 0000000..75d7da9
--- /dev/null
+++ b/src/hash/libwebidoidc-hash.c
@@ -0,0 +1,64 @@
+#include <utilities.h>
+#include <nettle/sha2.h>
+
+#define _(s) dgettext (PACKAGE, s)
+
+SCM_SYMBOL (sha256, "SHA-256");
+SCM_SYMBOL (sha384, "SHA-384");
+SCM_SYMBOL (sha512, "SHA-512");
+
+SCM_SYMBOL (unsupported_alg, "unsupported-alg");
+
+SCM_DEFINE (webidoidc_hash_g, "hash", 2, 0, 0, (SCM alg, SCM payload),
+	    "Hash something with @var{alg}, which must be @code{'SHA-256}, @code{'SHA-384} or @code{'SHA-512}.")
+{
+  size_t payload_size;
+  uint8_t *c_payload;
+  if (scm_is_string (payload))
+    {
+      return webidoidc_hash_g (alg, scm_string_to_utf8 (payload));
+    }
+  payload_size = scm_c_bytevector_length (payload);
+  c_payload = scm_gc_malloc_pointerless (payload_size, "To hash");
+  memcpy (c_payload, SCM_BYTEVECTOR_CONTENTS (payload), payload_size);
+  if (scm_is_eq (alg, sha256))
+    {
+      struct sha256_ctx hash;
+      uint8_t digest[SHA256_DIGEST_SIZE];
+      sha256_init (&hash);
+      sha256_update (&hash, payload_size, c_payload);
+      sha256_digest (&hash, SHA256_DIGEST_SIZE, digest);
+      return wrap_bytevector (SHA256_DIGEST_SIZE, digest);
+    }
+  else if (scm_is_eq (alg, sha384))
+    {
+      struct sha384_ctx hash;
+      uint8_t digest[SHA384_DIGEST_SIZE];
+      sha384_init (&hash);
+      sha384_update (&hash, payload_size, c_payload);
+      sha384_digest (&hash, SHA384_DIGEST_SIZE, digest);
+      return wrap_bytevector (SHA384_DIGEST_SIZE, digest);
+    }
+  else if (scm_is_eq (alg, sha512))
+    {
+      struct sha512_ctx hash;
+      uint8_t digest[SHA512_DIGEST_SIZE];
+      sha512_init (&hash);
+      sha512_update (&hash, payload_size, c_payload);
+      sha512_digest (&hash, SHA512_DIGEST_SIZE, digest);
+      return wrap_bytevector (SHA512_DIGEST_SIZE, digest);
+    }
+  else
+    {
+      scm_throw (unsupported_alg, scm_list_1 (alg));
+    }
+  return SCM_UNDEFINED;
+}
+
+void
+init_webidoidc_hash (void)
+{
+#ifndef SCM_MAGIC_SNARFER
+#include "libwebidoidc-hash.x"
+#endif /* not SCM_MAGIC_SNARFER */
+}