From 37da2899f40661e3e9631e497da8dc59b971cbd0 Mon Sep 17 00:00:00 2001 From: "Charles.Forsyth" Date: Fri, 22 Dec 2006 17:07:39 +0000 Subject: 20060303a --- libsec/port/egdecrypt.c | 28 ++++++++++++++++++++++++++++ 1 file changed, 28 insertions(+) create mode 100644 libsec/port/egdecrypt.c (limited to 'libsec/port/egdecrypt.c') diff --git a/libsec/port/egdecrypt.c b/libsec/port/egdecrypt.c new file mode 100644 index 00000000..24578800 --- /dev/null +++ b/libsec/port/egdecrypt.c @@ -0,0 +1,28 @@ +#include "os.h" +#include +#include + +mpint* +egdecrypt(EGpriv *priv, mpint *in, mpint *out) +{ + EGpub *pub = &priv->pub; + mpint *gamma, *delta; + mpint *p = pub->p; + int plen = mpsignif(p)+1; + int shift = ((plen+Dbits-1)/Dbits)*Dbits; + + if(out == nil) + out = mpnew(0); + gamma = mpnew(0); + delta = mpnew(0); + mpright(in, shift, gamma); + mpleft(gamma, shift, delta); + mpsub(in, delta, delta); + mpexp(gamma, priv->secret, p, out); + mpinvert(out, p, gamma); + mpmul(gamma, delta, out); + mpmod(out, p, out); + mpfree(gamma); + mpfree(delta); + return out; +} -- cgit v1.2.3