+/**
+ * The HMAC also exists in a stream version in a way analogous to the
+ * plain SHA1. Pass this as a context.
+ */
+typedef struct {
+ sha1_context ictx;
+ sha1_context octx;
+} sha1_hmac_context;
+
+void sha1_hmac_init(sha1_hmac_context *hd, const byte *key, uns keylen); /** Initialize HMAC with context @hd and the given key. See sha1_init(). */
+void sha1_hmac_update(sha1_hmac_context *hd, const byte *data, uns datalen); /** Hash another @datalen bytes of data. See sha1_update(). */
+byte *sha1_hmac_final(sha1_hmac_context *hd); /** Terminate the HMAC and return a pointer to the allocated hash. See sha1_final(). */
+