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Diffstat (limited to 'contrib/telnet/libtelnet/pk.c')
| -rw-r--r-- | contrib/telnet/libtelnet/pk.c | 266 |
1 files changed, 266 insertions, 0 deletions
diff --git a/contrib/telnet/libtelnet/pk.c b/contrib/telnet/libtelnet/pk.c new file mode 100644 index 0000000..78e474f --- /dev/null +++ b/contrib/telnet/libtelnet/pk.c @@ -0,0 +1,266 @@ +/* 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 <stdio.h> +#include <sys/time.h> +#include <string.h> +#include <fcntl.h> +#include <des.h> +#include "mp.h" +#include "pk.h" +#if defined(SOLARIS2) || defined(LINUX) +#include <stdlib.h> +#endif + +/* + * Choose top 128 bits of the common key to use as our idea key. + */ +static +extractideakey(ck, ideakey) + 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 +extractdeskey(ck, deskey) + 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); +#if DES_OSTHOLM + des_fixup_key_parity(deskey); +#else + des_set_odd_parity(deskey); +#endif + mfree(common); + mfree(secret); + mfree(public); + mfree(modulus); +} + + +/* + * Generate a seed + */ +void getseed(seed, seedsize) + char *seed; + int seedsize; +{ + int i,f; + int rseed; + struct timeval tv; + long devrand; + + (void)gettimeofday(&tv, (struct timezone *)NULL); + rseed = tv.tv_sec + tv.tv_usec; +/* XXX What the hell is this?! */ + for (i = 0; i < 8; i++) { + rseed ^= (rseed << 8); + } + + f=open("/dev/random",O_NONBLOCK|O_RDONLY); + if (f>=0) + { + read(f,&devrand,sizeof(devrand)); + close(f); + } + srand48((long)rseed^devrand); + + for (i = 0; i < seedsize; i++) { + seed[i] = (lrand48() & 0xff); + } +} + + +/* + * Generate a random public/secret key pair + */ +void genkeys(public, secret) + char *public; + char *secret; +{ + int 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 + */ +adjust(keyout, keyin) + 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(in, out, key) +char *in,*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((des_cblock *)in,(des_cblock *)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(in, out, key) +char *in,*out; +DesData *key; +{ + char buf[256]; + DesData i; + des_key_schedule k; + int l,n1,n2,op; + + 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((des_cblock *)buf,(des_cblock *)out,strlen(in)/2, + k,&i,DES_DECRYPT); + out[strlen(in)/2] = '\0'; +} |
