lib/libcrypt/crypt.c

198  * PC1ROT: MSB->LSB, PC1 permutation, rotate, and PC2 permutation.
201  * PC2ROT[0]: Inverse PC2 permutation, rotate, and PC2 permutation.
205  *	next by using a transformation that "undoes" the PC2 permutation,
206  *	rotates the code, and then applies PC2.  Unfortunately, PC2
207  *	transforms 56 bits into 48 bits, dropping 8 bits, so PC2 is not
208  *	invertible.  We get around that problem by using a modified PC2
363 /* note: each "row" of PC2 is left-padded with bits that make it invertible */
364 static const unsigned char PC2[] = {	/* permuted choice table 2 */
867 	 * PC1ROT - bit reverse, then PC1, then Rotate, then PC2.
872 		if ((k = PC2[i]) == 0)
890 	 * PC2ROT - PC2 inverse, then Rotate (once or twice), then PC2.
897 			if ((k = PC2[i]) == 0)
902 			if ((k = PC2[i]) == 0)