20060303a

1 files changed, 212 insertions, 0 deletions

diff --git a/libkeyring/egalg.c b/libkeyring/egalg.c
new file mode 100644
index 00000000..98567c95
--- /dev/null
+++ b/libkeyring/egalg.c
@@ -0,0 +1,212 @@
+#include <lib9.h>
+#include <kernel.h>
+#include <isa.h>
+#include "interp.h"
+#include "../libinterp/runt.h"
+#include "mp.h"
+#include "libsec.h"
+#include "keys.h"
+
+static char*	pkattr[] = { "p", "alpha", "key", nil };
+static char*	skattr[] = { "p", "alpha", "key", "!secret", nil };
+static char*	sigattr[] = { "r", "s", nil };
+
+static void*
+eg_str2sk(char *str, char **strp)
+{
+	EGpriv *eg;
+	char *p;
+
+	eg = egprivalloc();
+	eg->pub.p = base64tobig(str, &p);
+	eg->pub.alpha = base64tobig(p, &p);
+	eg->pub.key = base64tobig(p, &p);
+	eg->secret = base64tobig(p, &p);
+	if(strp)
+		*strp = p;
+	return eg;
+}
+
+static void*
+eg_str2pk(char *str, char **strp)
+{
+	EGpub *eg;
+	char *p;
+
+	eg = egpuballoc();
+	eg->p = base64tobig(str, &p);
+	eg->alpha = base64tobig(p, &p);
+	eg->key = base64tobig(p, &p);
+	if(strp)
+		*strp = p;
+	return eg;
+}
+
+static void*
+eg_str2sig(char *str, char **strp)
+{
+	EGsig *eg;
+	char *p;
+
+	eg = egsigalloc();
+	eg->r = base64tobig(str, &p);
+	eg->s = base64tobig(p, &p);
+	if(strp)
+		*strp = p;
+	return eg;
+}
+
+static int
+eg_sk2str(void *veg, char *buf, int len)
+{
+	EGpriv *eg;
+	char *cp, *ep;
+
+	eg = (EGpriv*)veg;
+	ep = buf + len - 1;
+	cp = buf;
+
+	cp += snprint(cp, ep - cp, "%U\n", eg->pub.p);
+	cp += snprint(cp, ep - cp, "%U\n", eg->pub.alpha);
+	cp += snprint(cp, ep - cp, "%U\n", eg->pub.key);
+	cp += snprint(cp, ep - cp, "%U\n", eg->secret);
+	*cp = 0;
+
+	return cp - buf;
+}
+
+static int
+eg_pk2str(void *veg, char *buf, int len)
+{
+	EGpub *eg;
+	char *cp, *ep;
+
+	eg = (EGpub*)veg;
+	ep = buf + len - 1;
+	cp = buf;
+
+	cp += snprint(cp, ep - cp, "%U\n", eg->p);
+	cp += snprint(cp, ep - cp, "%U\n", eg->alpha);
+	cp += snprint(cp, ep - cp, "%U\n", eg->key);
+	*cp = 0;
+
+	return cp - buf;
+}
+
+static int
+eg_sig2str(void *veg, char *buf, int len)
+{
+	EGsig *eg;
+	char *cp, *ep;
+
+	eg = veg;
+	ep = buf + len - 1;
+	cp = buf;
+
+	cp += snprint(cp, ep - cp, "%U\n", eg->r);
+	cp += snprint(cp, ep - cp, "%U\n", eg->s);
+	*cp = 0;
+
+	return cp - buf;
+}
+
+static void*
+eg_sk2pk(void *vs)
+{
+	return egprivtopub((EGpriv*)vs);
+}
+
+/* generate an el gamal secret key with new params */
+static void*
+eg_gen(int len)
+{
+	return eggen(len, 0);
+}
+
+/* generate an el gamal secret key with same params as a public key */
+static void*
+eg_genfrompk(void *vpub)
+{
+	EGpub *pub;
+	EGpriv *priv;
+	int nlen;
+
+	pub = vpub;
+	priv = egprivalloc();
+	priv->pub.p = mpcopy(pub->p);
+	priv->pub.alpha = mpcopy(pub->alpha);
+	nlen = mpsignif(pub->p);
+	pub = &priv->pub;
+	pub->key = mpnew(0);
+	priv->secret = mpnew(0);
+	mprand(nlen-1, genrandom, priv->secret);
+	mpexp(pub->alpha, priv->secret, pub->p, pub->key);
+	return priv;
+}
+
+static void*
+eg_sign(BigInt mp, void *key)
+{
+	return egsign((EGpriv*)key, mp);
+}
+
+static int
+eg_verify(BigInt mp, void *sig, void *key)
+{
+	return egverify((EGpub*)key, (EGsig*)sig, mp) == 0;
+}
+
+static void
+eg_freepub(void *a)
+{
+	egpubfree((EGpub*)a);
+}
+
+static void
+eg_freepriv(void *a)
+{
+	egprivfree((EGpriv*)a);
+}
+
+static void
+eg_freesig(void *a)
+{
+	egsigfree((EGsig*)a);
+}
+
+SigAlgVec*
+elgamalinit(void)
+{
+	SigAlgVec *vec;
+
+	vec = malloc(sizeof(SigAlgVec));
+	if(vec == nil)
+		return nil;
+
+	vec->name = "elgamal";
+
+	vec->pkattr = pkattr;
+	vec->skattr = skattr;
+	vec->sigattr = sigattr;
+
+	vec->str2sk = eg_str2sk;
+	vec->str2pk = eg_str2pk;
+	vec->str2sig = eg_str2sig;
+
+	vec->sk2str = eg_sk2str;
+	vec->pk2str = eg_pk2str;
+	vec->sig2str = eg_sig2str;
+
+	vec->sk2pk = eg_sk2pk;
+
+	vec->gensk = eg_gen;
+	vec->genskfrompk = eg_genfrompk;
+	vec->sign = eg_sign;
+	vec->verify = eg_verify;
+
+	vec->skfree = eg_freepriv;
+	vec->pkfree = eg_freepub;
+	vec->sigfree = eg_freesig;
+
+	return vec;
+}