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# beecrypt/rsa.c

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    00001
    00007 /*
    00008  * Copyright (c) 2000, 2001 Virtual Unlimited B.V.
    00009  *
    00010  * Author: Bob Deblier <bob@virtualunlimited.com>
    00011  *
    00012  * This library is free software; you can redistribute it and/or
    00013  * modify it under the terms of the GNU Lesser General Public
    00014  * License as published by the Free Software Foundation; either
    00015  * version 2.1 of the License, or (at your option) any later version.
    00016  *
    00017  * This library is distributed in the hope that it will be useful,
    00018  * but WITHOUT ANY WARRANTY; without even the implied warranty of
    00019  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
    00020  * Lesser General Public License for more details.
    00021  *
    00022  * You should have received a copy of the GNU Lesser General Public
    00023  * License along with this library; if not, write to the Free Software
    00024  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
    00025  *
    00026  */
    00027
    00028 #include "system.h"
    00029 #include "rsa.h"
    00030 #include "mp32.h"
    00031 #include "debug.h"
    00032
    00033 int rsapri(const rsakp* kp, const mp32number* m, mp32number* c)
    00034 {
    00035         register uint32  size = kp->n.size;
    00036         register uint32* temp = (uint32*) malloc((4*size+2) * sizeof(*temp));
    00037
    00038         if (temp)
    00039         {
    00040                 mp32nsize(c, size);
    00041                 mp32bpowmod_w(&kp->n, m->size, m->data, kp->d.size, kp->d.data, c->data, temp);
    00042
    00043                 free(temp);
    00044
    00045                 return 0;
    00046         }
    00047         return -1;
    00048 }
    00049
    00050
    00051 int rsapricrt(const rsakp* kp, const mp32number* m, mp32number* c)
    00052 {
    00053         register uint32  nsize = kp->n.size;
    00054         register uint32  psize = kp->p.size;
    00055         register uint32  qsize = kp->q.size;
    00056
    00057         register uint32* ptemp;
    00058         register uint32* qtemp;
    00059
    00060         /* m must be small enough to be exponentiated modulo p and q */
    00061         if (m->size > psize || m->size > qsize)
    00062                 return -1;
    00063
    00064         ptemp = (uint32*) malloc((6*psize+2)*sizeof(*ptemp));
    00065         if (ptemp == NULL)
    00066                 return -1;
    00067
    00068         qtemp = (uint32*) malloc((6*qsize+2)*sizeof(*qtemp));
    00069         if (qtemp == NULL)
    00070         {
    00071                 free(ptemp);
    00072                 return -1;
    00073         }
    00074
    00075         /* resize m for powmod p */
    00076         mp32setx(psize, ptemp+psize, m->size, m->data);
    00077
    00078         /* compute j1 = m^d1 mod p, store @ ptemp */
    00079 /*@-compdef@*/
    00080         mp32bpowmod_w(&kp->p, psize, ptemp+psize, kp->d1.size, kp->d1.data, ptemp, ptemp+2*psize);
    00081
    00082         /* resize m for powmod p */
    00083         mp32setx(qsize, qtemp+psize, m->size, m->data);
    00084
    00085         /* compute j2 = m^d2 mod q, store @ qtemp */
    00086         mp32bpowmod_w(&kp->q, qsize, qtemp+psize, kp->d2.size, kp->d2.data, qtemp, qtemp+2*qsize);
    00087 /*@=compdef@*/
    00088
    00089         /* compute j1-j2 mod p, store @ ptemp */
    00090         mp32bsubmod_w(&kp->p, psize, ptemp, qsize, qtemp, ptemp, ptemp+2*psize);
    00091
    00092         /* compute h = c*(j1-j2) mod p, store @ ptemp */
    00093         mp32bmulmod_w(&kp->p, psize, ptemp, psize, kp->c.data, ptemp, ptemp+2*psize);
    00094
    00095         /* make sure the signature gets the proper size */
    00096         mp32nsize(c, nsize);
    00097
    00098         /* compute s = h*q + j2 */
    00099         mp32mul(c->data, psize, ptemp, qsize, kp->q.modl);
    00100         (void) mp32addx(nsize, c->data, qsize, qtemp);
    00101
    00102         free(ptemp);
    00103         free(qtemp);
    00104
    00105         return 0;
    00106 }
    00107
    00111 int rsavrfy(const rsapk* pk, const mp32number* m, const mp32number* c)
    00112 {
    00113         int rc;
    00114         register uint32  size = pk->n.size;
    00115         register uint32* temp = (uint32*) malloc((5*size+2) * sizeof(*temp));
    00116
    00117         if (temp)
    00118         {
    00119                 mp32bpowmod_w(&pk->n, c->size, c->data, pk->e.size, pk->e.data, temp, temp+size);
    00120
    00121                 rc = mp32eqx(size, temp, m->size, m->data);
    00122
    00123                 free(temp);
    00124
    00125                 return rc;
    00126         }
    00127         return 0;
    00128 }