X-Git-Url: https://git.distorted.org.uk/u/mdw/catacomb/blobdiff_plain/f4535c6454395e6d56ce0091a07b6d4f7d54a47f..ffec48800022b6872951eca188d2ceedef8dd5c8:/mp.h

diff --git a/mp.h b/mp.h
index aa9bbac..7f96746 100644
--- a/mp.h
+++ b/mp.h
@@ -968,10 +968,25 @@ extern int mp_jacobi(mp */*a*/, mp */*n*/);
  *		work if %$p$% is composite: you must factor the modulus, take
  *		a square root mod each factor, and recombine the results
  *		using the Chinese Remainder Theorem.
+ *
+ *		We guarantee that the square root returned is the smallest
+ *		one (i.e., the `positive' square root).
  */
 
 extern mp *mp_modsqrt(mp */*d*/, mp */*a*/, mp */*p*/);
 
+/* --- @mp_modexp@ --- *
+ *
+ * Arguments:	@mp *d@ = fake destination
+ *		@mp *x@ = base of exponentiation
+ *		@mp *e@ = exponent
+ *		@mp *n@ = modulus (must be positive)
+ *
+ * Returns:	The value %$x^e \bmod n$%.
+ */
+
+extern mp *mp_modexp(mp */*d*/, mp */*x*/, mp */*e*/, mp */*n*/);
+
 /*----- Test harness support ----------------------------------------------*/
 
 #include <mLib/testrig.h>