/*
* convert the key to a bit pattern
* obuf bit pattern
* inbuf the key itself
*/
void
expand_des_key(char *obuf, char *inbuf)
{
int i, j; /* counter in a for loop */
int nbuf[64]; /* used for hex/key translation */
/*
* leading '0x' or '0X' == hex key
*/
if (inbuf[0] == '0' && (inbuf[1] == 'x' || inbuf[1] == 'X')) {
inbuf = &inbuf[2];
/*
* now translate it, bombing on any illegal hex digit
*/
for (i = 0; inbuf[i] && i < 16; i++)
if ((nbuf[i] = hex_to_binary((int) inbuf[i], 16)) == -1)
des_error("bad hex digit in key");
while (i < 16)
nbuf[i++] = 0;
for (i = 0; i < 8; i++)
obuf[i] =
((nbuf[2*i]&0xf)<<4) | (nbuf[2*i+1]&0xf);
/* preserve parity bits */
pflag = 1;
return;
}
/*
* leading '0b' or '0B' == binary key
*/
if (inbuf[0] == '0' && (inbuf[1] == 'b' || inbuf[1] == 'B')) {
inbuf = &inbuf[2];
/*
* now translate it, bombing on any illegal binary digit
*/
for (i = 0; inbuf[i] && i < 16; i++)
if ((nbuf[i] = hex_to_binary((int) inbuf[i], 2)) == -1)
des_error("bad binary digit in key");
while (i < 64)
nbuf[i++] = 0;
for (i = 0; i < 8; i++)
for (j = 0; j < 8; j++)
obuf[i] = (obuf[i]<<1)|nbuf[8*i+j];
/* preserve parity bits */
pflag = 1;
return;
}
/*
* no special leader -- ASCII
*/
strncpy(obuf, inbuf, 8);
}
/*
* This decrypts using the Cipher Block Chaining mode of DES
* msgbuf I/O buffer
* fp input file descriptor
*/
int
cbc_decode(char *msgbuf, FILE *fp)
{
DES_cblock inbuf; /* temp buffer for initialization vector */
int n; /* number of bytes actually read */
int c; /* used to test for EOF */
int inverse = 1; /* 0 to encrypt, 1 to decrypt */
if ((n = READ(msgbuf, 8, fp)) == 8) {
/*
* do the transformation
*/
MEMCPY(inbuf, msgbuf, 8);
DES_XFORM((DES_cblock *)msgbuf);
for (c = 0; c < 8; c++)
msgbuf[c] ^= ivec[c];
MEMCPY(ivec, inbuf, 8);
/*
* if the last one, handle it specially
*/
if ((c = fgetc(fp)) == EOF) {
n = msgbuf[7];
if (n < 0 || n > 7) {
des_error("decryption failed (block corrupted)");
return EOF;
}
} else
ungetc(c, fp);
return n;
}
if (n > 0)
des_error("decryption failed (incomplete block)");
else if (n < 0)
des_error("cannot read file");
return EOF;
}
/*
* This decrypts using the Cipher Block Chaining mode of DES
* msgbuf I/O buffer
* fp input file descriptor
*/
int
cbc_decode(char *msgbuf, FILE *fp)
{
Desbuf tbuf; /* temp buffer for initialization vector */
int n; /* number of bytes actually read */
int c; /* used to test for EOF */
int inverse = 1; /* 0 to encrypt, 1 to decrypt */
if ((n = READ(BUFFER(msgbuf), 8, fp)) == 8) {
/*
* do the transformation
*/
MEMCPY(BUFFER(tbuf), BUFFER(msgbuf), 8);
DES_XFORM(UBUFFER(msgbuf));
for (c = 0; c < 8; c++)
UCHAR(msgbuf, c) ^= UCHAR(ivec, c);
MEMCPY(BUFFER(ivec), BUFFER(tbuf), 8);
/*
* if the last one, handle it specially
*/
if ((c = fgetc(fp)) == EOF) {
n = CHAR(msgbuf, 7);
if (n < 0 || n > 7) {
des_error("decryption failed (block corrupted)");
return EOF;
}
} else
(void)ungetc(c, fp);
return n;
}
if (n > 0)
des_error("decryption failed (incomplete block)");
else if (n < 0)
des_error("cannot read file");
return EOF;
}
