Orange Pi5 kernel

^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  1) // SPDX-License-Identifier: GPL-2.0-or-later
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  2) /*
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  3)  * Cryptographic API
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  4)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  5)  * ARC4 Cipher Algorithm
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  6)  *
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  7)  * Jon Oberheide <jon@oberheide.org>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  8)  */
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300  9) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 10) #include <crypto/arc4.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 11) #include <linux/module.h>
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 12) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 13) int arc4_setkey(struct arc4_ctx *ctx, const u8 *in_key, unsigned int key_len)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 14) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 15) 	int i, j = 0, k = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 16) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 17) 	ctx->x = 1;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 18) 	ctx->y = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 19) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 20) 	for (i = 0; i < 256; i++)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 21) 		ctx->S[i] = i;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 22) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 23) 	for (i = 0; i < 256; i++) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 24) 		u32 a = ctx->S[i];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 25) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 26) 		j = (j + in_key[k] + a) & 0xff;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 27) 		ctx->S[i] = ctx->S[j];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 28) 		ctx->S[j] = a;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 29) 		if (++k >= key_len)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 30) 			k = 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 31) 	}
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 32) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 33) 	return 0;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 34) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 35) EXPORT_SYMBOL(arc4_setkey);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 36) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 37) void arc4_crypt(struct arc4_ctx *ctx, u8 *out, const u8 *in, unsigned int len)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 38) {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 39) 	u32 *const S = ctx->S;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 40) 	u32 x, y, a, b;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 41) 	u32 ty, ta, tb;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 42) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 43) 	if (len == 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 44) 		return;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 45) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 46) 	x = ctx->x;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 47) 	y = ctx->y;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 48) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 49) 	a = S[x];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 50) 	y = (y + a) & 0xff;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 51) 	b = S[y];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 52) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 53) 	do {
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 54) 		S[y] = a;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 55) 		a = (a + b) & 0xff;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 56) 		S[x] = b;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 57) 		x = (x + 1) & 0xff;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 58) 		ta = S[x];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 59) 		ty = (y + ta) & 0xff;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 60) 		tb = S[ty];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 61) 		*out++ = *in++ ^ S[a];
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 62) 		if (--len == 0)
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 63) 			break;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 64) 		y = ty;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 65) 		a = ta;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 66) 		b = tb;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 67) 	} while (true);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 68) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 69) 	ctx->x = x;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 70) 	ctx->y = y;
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 71) }
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 72) EXPORT_SYMBOL(arc4_crypt);
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 73) 
^8f3ce5b39 (kx 2023-10-28 12:00:06 +0300 74) MODULE_LICENSE("GPL");