+void modmul(Bignum a, Bignum b, Bignum mod, Bignum result);
+void decbn(Bignum n);
+extern Bignum Zero, One;
+int ssh1_read_bignum(unsigned char *data, Bignum *result);
+int ssh1_bignum_bitcount(Bignum bn);
+int ssh1_bignum_length(Bignum bn);
+int bignum_byte(Bignum bn, int i);
+int ssh1_write_bignum(void *data, Bignum bn);