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Diffstat (limited to 'lib/libtelnet/pk.c')
| -rw-r--r-- | lib/libtelnet/pk.c | 269 |
1 files changed, 269 insertions, 0 deletions
diff --git a/lib/libtelnet/pk.c b/lib/libtelnet/pk.c new file mode 100644 index 0000000..56444ed --- /dev/null +++ b/lib/libtelnet/pk.c @@ -0,0 +1,269 @@ +/*- + * Copyright (c) 1991, 1993 + * Dave Safford. All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * 3. Neither the name of the University nor the names of its contributors + * may be used to endorse or promote products derived from this software + * without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + * + */ + +#include <sys/cdefs.h> + +__FBSDID("$FreeBSD: src/crypto/telnet/libtelnet/pk.c,v 1.2.2.3 2002/04/13 10:59:07 markm Exp $"); + +/* public key routines */ +/* functions: + genkeys(char *public, char *secret) + common_key(char *secret, char *public, desData *deskey) + pk_encode(char *in, *out, DesData *deskey); + pk_decode(char *in, *out, DesData *deskey); + where + char public[HEXKEYBYTES + 1]; + char secret[HEXKEYBYTES + 1]; + */ + +#include <sys/time.h> +#include <openssl/des.h> +#include <fcntl.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> + +#include "mp.h" +#include "pk.h" + +static void adjust(char keyout[HEXKEYBYTES+1], char *keyin); + +/* + * Choose top 128 bits of the common key to use as our idea key. + */ +static void +extractideakey(MINT *ck, IdeaData *ideakey) +{ + MINT *a; + MINT *z; + short r; + int i; + short base = (1 << 8); + char *k; + + z = itom(0); + a = itom(0); + madd(ck, z, a); + for (i = 0; i < ((KEYSIZE - 128) / 8); i++) { + sdiv(a, base, a, &r); + } + k = (char *)ideakey; + for (i = 0; i < 16; i++) { + sdiv(a, base, a, &r); + *k++ = r; + } + mfree(z); + mfree(a); +} + +/* + * Choose middle 64 bits of the common key to use as our des key, possibly + * overwriting the lower order bits by setting parity. + */ +static void +extractdeskey(MINT *ck, DesData *deskey) +{ + MINT *a; + MINT *z; + short r; + int i; + short base = (1 << 8); + char *k; + + z = itom(0); + a = itom(0); + madd(ck, z, a); + for (i = 0; i < ((KEYSIZE - 64) / 2) / 8; i++) { + sdiv(a, base, a, &r); + } + k = (char *)deskey; + for (i = 0; i < 8; i++) { + sdiv(a, base, a, &r); + *k++ = r; + } + mfree(z); + mfree(a); +} + +/* + * get common key from my secret key and his public key + */ +void +common_key(char *xsecret, char *xpublic, IdeaData *ideakey, DesData *deskey) +{ + MINT *public; + MINT *secret; + MINT *common; + MINT *modulus = xtom(HEXMODULUS); + + public = xtom(xpublic); + secret = xtom(xsecret); + common = itom(0); + pow(public, secret, modulus, common); + extractdeskey(common, deskey); + extractideakey(common, ideakey); + des_set_odd_parity(deskey); + mfree(common); + mfree(secret); + mfree(public); + mfree(modulus); +} + +/* + * Generate a seed + */ +static void +getseed(char *seed, int seedsize) +{ + int i; + + srandomdev(); + for (i = 0; i < seedsize; i++) { + seed[i] = random() & 0xff; + } +} + +/* + * Generate a random public/secret key pair + */ +void +genkeys(char *public, char *secret) +{ + size_t i; + +# define BASEBITS (8*sizeof(short) - 1) +# define BASE (1 << BASEBITS) + + MINT *pk = itom(0); + MINT *sk = itom(0); + MINT *tmp; + MINT *base = itom(BASE); + MINT *root = itom(PROOT); + MINT *modulus = xtom(HEXMODULUS); + short r; + unsigned short seed[KEYSIZE/BASEBITS + 1]; + char *xkey; + + getseed((char *)seed, sizeof(seed)); + for (i = 0; i < KEYSIZE/BASEBITS + 1; i++) { + r = seed[i] % BASE; + tmp = itom(r); + mult(sk, base, sk); + madd(sk, tmp, sk); + mfree(tmp); + } + tmp = itom(0); + mdiv(sk, modulus, tmp, sk); + mfree(tmp); + pow(root, sk, modulus, pk); + xkey = mtox(sk); + adjust(secret, xkey); + xkey = mtox(pk); + adjust(public, xkey); + mfree(sk); + mfree(base); + mfree(pk); + mfree(root); + mfree(modulus); +} + +/* + * Adjust the input key so that it is 0-filled on the left + */ +static void +adjust(char keyout[HEXKEYBYTES+1], char *keyin) +{ + char *p; + char *s; + + for (p = keyin; *p; p++) + ; + for (s = keyout + HEXKEYBYTES; p >= keyin; p--, s--) { + *s = *p; + } + while (s >= keyout) { + *s-- = '0'; + } +} + +static char hextab[17] = "0123456789ABCDEF"; + +/* given a DES key, cbc encrypt and translate input to terminated hex */ +void +pk_encode(char *in, char *out, DesData *key) +{ + char buf[256]; + DesData i; + des_key_schedule k; + int l,op,deslen; + + memset(&i,0,sizeof(i)); + memset(buf,0,sizeof(buf)); + deslen = ((strlen(in) + 7)/8)*8; + des_key_sched(key, k); + des_cbc_encrypt(in,buf,deslen, k,&i,DES_ENCRYPT); + for (l=0,op=0;l<deslen;l++) { + out[op++] = hextab[(buf[l] & 0xf0) >> 4]; + out[op++] = hextab[(buf[l] & 0x0f)]; + } + out[op] = '\0'; +} + +/* given a DES key, translate input from hex and decrypt */ +void +pk_decode(char *in, char *out, DesData *key) +{ + char buf[256]; + DesData i; + des_key_schedule k; + int n1,n2,op; + size_t l; + + memset(&i,0,sizeof(i)); + memset(buf,0,sizeof(buf)); + for (l=0,op=0;l<strlen(in)/2;l++,op+=2) { + if(in[op] == '0' && in[op+1] == '0') { + buf[l] = '\0'; + break; + } + if (in[op] > '9') + n1 = in[op] - 'A' + 10; + else + n1 = in[op] - '0'; + if (in[op+1] > '9') + n2 = in[op+1] - 'A' + 10; + else + n2 = in[op+1] - '0'; + buf[l] = n1*16 +n2; + } + des_key_sched(key, k); + des_cbc_encrypt(buf,out,strlen(in)/2, k,&i,DES_DECRYPT); + out[strlen(in)/2] = '\0'; +} |