11759 sys/sha1.h should provide SHA1_BLOCK_LENGTH

Reviewed by: Andy Fiddaman <omnios@citrus-it.co.uk>
Reviewed by: Jason Lippert <jason@glasspelican.ca>
Approved by: Dan McDonald <danmcd@joyent.com>

usr/src/uts/common/sys/sha1.h

@@ -48,6 +48,7 @@ typedef struct {
 	} buf_un;
 } SHA1_CTX;
 
+#define	SHA1_BLOCK_LENGTH 64
 #define	SHA1_DIGEST_LENGTH 20
 
 void SHA1Init(SHA1_CTX *);