summaryrefslogtreecommitdiff
path: root/rijndael.c
diff options
context:
space:
mode:
authorDamien Miller <djm@mindrot.org>2000-10-14 16:23:11 +1100
committerDamien Miller <djm@mindrot.org>2000-10-14 16:23:11 +1100
commit874d77bb134a21a5cf625956b60173376a993ba8 (patch)
tree93dd73b2ff1fbf0ad5f3978a2c4e0d8438a0bf7c /rijndael.c
parent89d9796fbedef4eed6956a2c095c7cc25330c28d (diff)
- (djm) Big OpenBSD sync:
- markus@cvs.openbsd.org 2000/09/30 10:27:44 [log.c] allow loglevel debug - markus@cvs.openbsd.org 2000/10/03 11:59:57 [packet.c] hmac->mac - markus@cvs.openbsd.org 2000/10/03 12:03:03 [auth-krb4.c auth-passwd.c auth-rh-rsa.c auth-rhosts.c auth-rsa.c auth1.c] move fake-auth from auth1.c to individual auth methods, disables s/key in debug-msg - markus@cvs.openbsd.org 2000/10/03 12:16:48 ssh.c do not resolve canonname, i have no idea why this was added oin ossh - markus@cvs.openbsd.org 2000/10/09 15:30:44 ssh-keygen.1 ssh-keygen.c -X now reads private ssh.com DSA keys, too. - markus@cvs.openbsd.org 2000/10/09 15:32:34 auth-options.c clear options on every call. - markus@cvs.openbsd.org 2000/10/09 15:51:00 authfd.c authfd.h interop with ssh-agent2, from <res@shore.net> - markus@cvs.openbsd.org 2000/10/10 14:20:45 compat.c use rexexp for version string matching - provos@cvs.openbsd.org 2000/10/10 22:02:18 [kex.c kex.h myproposal.h ssh.h ssh2.h sshconnect2.c sshd.c dh.c dh.h] First rough implementation of the diffie-hellman group exchange. The client can ask the server for bigger groups to perform the diffie-hellman in, thus increasing the attack complexity when using ciphers with longer keys. University of Windsor provided network, T the company. - markus@cvs.openbsd.org 2000/10/11 13:59:52 [auth-rsa.c auth2.c] clear auth options unless auth sucessfull - markus@cvs.openbsd.org 2000/10/11 14:00:27 [auth-options.h] clear auth options unless auth sucessfull - markus@cvs.openbsd.org 2000/10/11 14:03:27 [scp.1 scp.c] support 'scp -o' with help from mouring@pconline.com - markus@cvs.openbsd.org 2000/10/11 14:11:35 [dh.c] Wall - markus@cvs.openbsd.org 2000/10/11 14:14:40 [auth.h auth2.c readconf.c readconf.h readpass.c servconf.c servconf.h] [ssh.h sshconnect2.c sshd_config auth2-skey.c cli.c cli.h] add support for s/key (kbd-interactive) to ssh2, based on work by mkiernan@avantgo.com and me - markus@cvs.openbsd.org 2000/10/11 14:27:24 [auth.c auth1.c auth2.c authfile.c cipher.c cipher.h kex.c kex.h] [myproposal.h packet.c readconf.c session.c ssh.c ssh.h sshconnect1.c] [sshconnect2.c sshd.c] new cipher framework - markus@cvs.openbsd.org 2000/10/11 14:45:21 [cipher.c] remove DES - markus@cvs.openbsd.org 2000/10/12 03:59:20 [cipher.c cipher.h sshconnect1.c sshconnect2.c sshd.c] enable DES in SSH-1 clients only - markus@cvs.openbsd.org 2000/10/12 08:21:13 [kex.h packet.c] remove unused - markus@cvs.openbsd.org 2000/10/13 12:34:46 [sshd.c] Kludge for F-Secure Macintosh < 1.0.2; appro@fy.chalmers.se - markus@cvs.openbsd.org 2000/10/13 12:59:15 [cipher.c cipher.h myproposal.h rijndael.c rijndael.h] rijndael/aes support - markus@cvs.openbsd.org 2000/10/13 13:10:54 [sshd.8] more info about -V - markus@cvs.openbsd.org 2000/10/13 13:12:02 [myproposal.h] prefer no compression
Diffstat (limited to 'rijndael.c')
-rw-r--r--rijndael.c493
1 files changed, 493 insertions, 0 deletions
diff --git a/rijndael.c b/rijndael.c
new file mode 100644
index 00000000..bb592bc2
--- /dev/null
+++ b/rijndael.c
@@ -0,0 +1,493 @@
+/* $OpenBSD: rijndael.c,v 1.1 2000/10/13 18:59:14 markus Exp $ */
+
+/* This is an independent implementation of the encryption algorithm: */
+/* */
+/* RIJNDAEL by Joan Daemen and Vincent Rijmen */
+/* */
+/* which is a candidate algorithm in the Advanced Encryption Standard */
+/* programme of the US National Institute of Standards and Technology. */
+/* */
+/* Copyright in this implementation is held by Dr B R Gladman but I */
+/* hereby give permission for its free direct or derivative use subject */
+/* to acknowledgment of its origin and compliance with any conditions */
+/* that the originators of the algorithm place on its exploitation. */
+/* */
+/* Dr Brian Gladman (gladman@seven77.demon.co.uk) 14th January 1999 */
+
+/* Timing data for Rijndael (rijndael.c)
+
+Algorithm: rijndael (rijndael.c)
+
+128 bit key:
+Key Setup: 305/1389 cycles (encrypt/decrypt)
+Encrypt: 374 cycles = 68.4 mbits/sec
+Decrypt: 352 cycles = 72.7 mbits/sec
+Mean: 363 cycles = 70.5 mbits/sec
+
+192 bit key:
+Key Setup: 277/1595 cycles (encrypt/decrypt)
+Encrypt: 439 cycles = 58.3 mbits/sec
+Decrypt: 425 cycles = 60.2 mbits/sec
+Mean: 432 cycles = 59.3 mbits/sec
+
+256 bit key:
+Key Setup: 374/1960 cycles (encrypt/decrypt)
+Encrypt: 502 cycles = 51.0 mbits/sec
+Decrypt: 498 cycles = 51.4 mbits/sec
+Mean: 500 cycles = 51.2 mbits/sec
+
+*/
+
+#include <sys/types.h>
+#include "rijndael.h"
+
+void gen_tabs __P((void));
+
+/* 3. Basic macros for speeding up generic operations */
+
+/* Circular rotate of 32 bit values */
+
+#define rotr(x,n) (((x) >> ((int)(n))) | ((x) << (32 - (int)(n))))
+#define rotl(x,n) (((x) << ((int)(n))) | ((x) >> (32 - (int)(n))))
+
+/* Invert byte order in a 32 bit variable */
+
+#define bswap(x) (rotl(x, 8) & 0x00ff00ff | rotr(x, 8) & 0xff00ff00)
+
+/* Extract byte from a 32 bit quantity (little endian notation) */
+
+#define byte(x,n) ((u1byte)((x) >> (8 * n)))
+
+#if BYTE_ORDER != LITTLE_ENDIAN
+#define BLOCK_SWAP
+#endif
+
+/* For inverting byte order in input/output 32 bit words if needed */
+
+#ifdef BLOCK_SWAP
+#define BYTE_SWAP
+#define WORD_SWAP
+#endif
+
+#ifdef BYTE_SWAP
+#define io_swap(x) bswap(x)
+#else
+#define io_swap(x) (x)
+#endif
+
+/* For inverting the byte order of input/output blocks if needed */
+
+#ifdef WORD_SWAP
+
+#define get_block(x) \
+ ((u4byte*)(x))[0] = io_swap(in_blk[3]); \
+ ((u4byte*)(x))[1] = io_swap(in_blk[2]); \
+ ((u4byte*)(x))[2] = io_swap(in_blk[1]); \
+ ((u4byte*)(x))[3] = io_swap(in_blk[0])
+
+#define put_block(x) \
+ out_blk[3] = io_swap(((u4byte*)(x))[0]); \
+ out_blk[2] = io_swap(((u4byte*)(x))[1]); \
+ out_blk[1] = io_swap(((u4byte*)(x))[2]); \
+ out_blk[0] = io_swap(((u4byte*)(x))[3])
+
+#define get_key(x,len) \
+ ((u4byte*)(x))[4] = ((u4byte*)(x))[5] = \
+ ((u4byte*)(x))[6] = ((u4byte*)(x))[7] = 0; \
+ switch((((len) + 63) / 64)) { \
+ case 2: \
+ ((u4byte*)(x))[0] = io_swap(in_key[3]); \
+ ((u4byte*)(x))[1] = io_swap(in_key[2]); \
+ ((u4byte*)(x))[2] = io_swap(in_key[1]); \
+ ((u4byte*)(x))[3] = io_swap(in_key[0]); \
+ break; \
+ case 3: \
+ ((u4byte*)(x))[0] = io_swap(in_key[5]); \
+ ((u4byte*)(x))[1] = io_swap(in_key[4]); \
+ ((u4byte*)(x))[2] = io_swap(in_key[3]); \
+ ((u4byte*)(x))[3] = io_swap(in_key[2]); \
+ ((u4byte*)(x))[4] = io_swap(in_key[1]); \
+ ((u4byte*)(x))[5] = io_swap(in_key[0]); \
+ break; \
+ case 4: \
+ ((u4byte*)(x))[0] = io_swap(in_key[7]); \
+ ((u4byte*)(x))[1] = io_swap(in_key[6]); \
+ ((u4byte*)(x))[2] = io_swap(in_key[5]); \
+ ((u4byte*)(x))[3] = io_swap(in_key[4]); \
+ ((u4byte*)(x))[4] = io_swap(in_key[3]); \
+ ((u4byte*)(x))[5] = io_swap(in_key[2]); \
+ ((u4byte*)(x))[6] = io_swap(in_key[1]); \
+ ((u4byte*)(x))[7] = io_swap(in_key[0]); \
+ }
+
+#else
+
+#define get_block(x) \
+ ((u4byte*)(x))[0] = io_swap(in_blk[0]); \
+ ((u4byte*)(x))[1] = io_swap(in_blk[1]); \
+ ((u4byte*)(x))[2] = io_swap(in_blk[2]); \
+ ((u4byte*)(x))[3] = io_swap(in_blk[3])
+
+#define put_block(x) \
+ out_blk[0] = io_swap(((u4byte*)(x))[0]); \
+ out_blk[1] = io_swap(((u4byte*)(x))[1]); \
+ out_blk[2] = io_swap(((u4byte*)(x))[2]); \
+ out_blk[3] = io_swap(((u4byte*)(x))[3])
+
+#define get_key(x,len) \
+ ((u4byte*)(x))[4] = ((u4byte*)(x))[5] = \
+ ((u4byte*)(x))[6] = ((u4byte*)(x))[7] = 0; \
+ switch((((len) + 63) / 64)) { \
+ case 4: \
+ ((u4byte*)(x))[6] = io_swap(in_key[6]); \
+ ((u4byte*)(x))[7] = io_swap(in_key[7]); \
+ case 3: \
+ ((u4byte*)(x))[4] = io_swap(in_key[4]); \
+ ((u4byte*)(x))[5] = io_swap(in_key[5]); \
+ case 2: \
+ ((u4byte*)(x))[0] = io_swap(in_key[0]); \
+ ((u4byte*)(x))[1] = io_swap(in_key[1]); \
+ ((u4byte*)(x))[2] = io_swap(in_key[2]); \
+ ((u4byte*)(x))[3] = io_swap(in_key[3]); \
+ }
+
+#endif
+
+#define LARGE_TABLES
+
+u1byte pow_tab[256];
+u1byte log_tab[256];
+u1byte sbx_tab[256];
+u1byte isb_tab[256];
+u4byte rco_tab[ 10];
+u4byte ft_tab[4][256];
+u4byte it_tab[4][256];
+
+#ifdef LARGE_TABLES
+ u4byte fl_tab[4][256];
+ u4byte il_tab[4][256];
+#endif
+
+u4byte tab_gen = 0;
+
+#define ff_mult(a,b) (a && b ? pow_tab[(log_tab[a] + log_tab[b]) % 255] : 0)
+
+#define f_rn(bo, bi, n, k) \
+ bo[n] = ft_tab[0][byte(bi[n],0)] ^ \
+ ft_tab[1][byte(bi[(n + 1) & 3],1)] ^ \
+ ft_tab[2][byte(bi[(n + 2) & 3],2)] ^ \
+ ft_tab[3][byte(bi[(n + 3) & 3],3)] ^ *(k + n)
+
+#define i_rn(bo, bi, n, k) \
+ bo[n] = it_tab[0][byte(bi[n],0)] ^ \
+ it_tab[1][byte(bi[(n + 3) & 3],1)] ^ \
+ it_tab[2][byte(bi[(n + 2) & 3],2)] ^ \
+ it_tab[3][byte(bi[(n + 1) & 3],3)] ^ *(k + n)
+
+#ifdef LARGE_TABLES
+
+#define ls_box(x) \
+ ( fl_tab[0][byte(x, 0)] ^ \
+ fl_tab[1][byte(x, 1)] ^ \
+ fl_tab[2][byte(x, 2)] ^ \
+ fl_tab[3][byte(x, 3)] )
+
+#define f_rl(bo, bi, n, k) \
+ bo[n] = fl_tab[0][byte(bi[n],0)] ^ \
+ fl_tab[1][byte(bi[(n + 1) & 3],1)] ^ \
+ fl_tab[2][byte(bi[(n + 2) & 3],2)] ^ \
+ fl_tab[3][byte(bi[(n + 3) & 3],3)] ^ *(k + n)
+
+#define i_rl(bo, bi, n, k) \
+ bo[n] = il_tab[0][byte(bi[n],0)] ^ \
+ il_tab[1][byte(bi[(n + 3) & 3],1)] ^ \
+ il_tab[2][byte(bi[(n + 2) & 3],2)] ^ \
+ il_tab[3][byte(bi[(n + 1) & 3],3)] ^ *(k + n)
+
+#else
+
+#define ls_box(x) \
+ ((u4byte)sbx_tab[byte(x, 0)] << 0) ^ \
+ ((u4byte)sbx_tab[byte(x, 1)] << 8) ^ \
+ ((u4byte)sbx_tab[byte(x, 2)] << 16) ^ \
+ ((u4byte)sbx_tab[byte(x, 3)] << 24)
+
+#define f_rl(bo, bi, n, k) \
+ bo[n] = (u4byte)sbx_tab[byte(bi[n],0)] ^ \
+ rotl(((u4byte)sbx_tab[byte(bi[(n + 1) & 3],1)]), 8) ^ \
+ rotl(((u4byte)sbx_tab[byte(bi[(n + 2) & 3],2)]), 16) ^ \
+ rotl(((u4byte)sbx_tab[byte(bi[(n + 3) & 3],3)]), 24) ^ *(k + n)
+
+#define i_rl(bo, bi, n, k) \
+ bo[n] = (u4byte)isb_tab[byte(bi[n],0)] ^ \
+ rotl(((u4byte)isb_tab[byte(bi[(n + 3) & 3],1)]), 8) ^ \
+ rotl(((u4byte)isb_tab[byte(bi[(n + 2) & 3],2)]), 16) ^ \
+ rotl(((u4byte)isb_tab[byte(bi[(n + 1) & 3],3)]), 24) ^ *(k + n)
+
+#endif
+
+void
+gen_tabs(void)
+{
+ u4byte i, t;
+ u1byte p, q;
+
+ /* log and power tables for GF(2**8) finite field with */
+ /* 0x11b as modular polynomial - the simplest prmitive */
+ /* root is 0x11, used here to generate the tables */
+
+ for(i = 0,p = 1; i < 256; ++i) {
+ pow_tab[i] = (u1byte)p; log_tab[p] = (u1byte)i;
+
+ p = p ^ (p << 1) ^ (p & 0x80 ? 0x01b : 0);
+ }
+
+ log_tab[1] = 0; p = 1;
+
+ for(i = 0; i < 10; ++i) {
+ rco_tab[i] = p;
+
+ p = (p << 1) ^ (p & 0x80 ? 0x1b : 0);
+ }
+
+ /* note that the affine byte transformation matrix in */
+ /* rijndael specification is in big endian format with */
+ /* bit 0 as the most significant bit. In the remainder */
+ /* of the specification the bits are numbered from the */
+ /* least significant end of a byte. */
+
+ for(i = 0; i < 256; ++i) {
+ p = (i ? pow_tab[255 - log_tab[i]] : 0); q = p;
+ q = (q >> 7) | (q << 1); p ^= q;
+ q = (q >> 7) | (q << 1); p ^= q;
+ q = (q >> 7) | (q << 1); p ^= q;
+ q = (q >> 7) | (q << 1); p ^= q ^ 0x63;
+ sbx_tab[i] = (u1byte)p; isb_tab[p] = (u1byte)i;
+ }
+
+ for(i = 0; i < 256; ++i) {
+ p = sbx_tab[i];
+
+#ifdef LARGE_TABLES
+
+ t = p; fl_tab[0][i] = t;
+ fl_tab[1][i] = rotl(t, 8);
+ fl_tab[2][i] = rotl(t, 16);
+ fl_tab[3][i] = rotl(t, 24);
+#endif
+ t = ((u4byte)ff_mult(2, p)) |
+ ((u4byte)p << 8) |
+ ((u4byte)p << 16) |
+ ((u4byte)ff_mult(3, p) << 24);
+
+ ft_tab[0][i] = t;
+ ft_tab[1][i] = rotl(t, 8);
+ ft_tab[2][i] = rotl(t, 16);
+ ft_tab[3][i] = rotl(t, 24);
+
+ p = isb_tab[i];
+
+#ifdef LARGE_TABLES
+
+ t = p; il_tab[0][i] = t;
+ il_tab[1][i] = rotl(t, 8);
+ il_tab[2][i] = rotl(t, 16);
+ il_tab[3][i] = rotl(t, 24);
+#endif
+ t = ((u4byte)ff_mult(14, p)) |
+ ((u4byte)ff_mult( 9, p) << 8) |
+ ((u4byte)ff_mult(13, p) << 16) |
+ ((u4byte)ff_mult(11, p) << 24);
+
+ it_tab[0][i] = t;
+ it_tab[1][i] = rotl(t, 8);
+ it_tab[2][i] = rotl(t, 16);
+ it_tab[3][i] = rotl(t, 24);
+ }
+
+ tab_gen = 1;
+};
+
+#define star_x(x) (((x) & 0x7f7f7f7f) << 1) ^ ((((x) & 0x80808080) >> 7) * 0x1b)
+
+#define imix_col(y,x) \
+ u = star_x(x); \
+ v = star_x(u); \
+ w = star_x(v); \
+ t = w ^ (x); \
+ (y) = u ^ v ^ w; \
+ (y) ^= rotr(u ^ t, 8) ^ \
+ rotr(v ^ t, 16) ^ \
+ rotr(t,24)
+
+/* initialise the key schedule from the user supplied key */
+
+#define loop4(i) \
+{ t = ls_box(rotr(t, 8)) ^ rco_tab[i]; \
+ t ^= e_key[4 * i]; e_key[4 * i + 4] = t; \
+ t ^= e_key[4 * i + 1]; e_key[4 * i + 5] = t; \
+ t ^= e_key[4 * i + 2]; e_key[4 * i + 6] = t; \
+ t ^= e_key[4 * i + 3]; e_key[4 * i + 7] = t; \
+}
+
+#define loop6(i) \
+{ t = ls_box(rotr(t, 8)) ^ rco_tab[i]; \
+ t ^= e_key[6 * i]; e_key[6 * i + 6] = t; \
+ t ^= e_key[6 * i + 1]; e_key[6 * i + 7] = t; \
+ t ^= e_key[6 * i + 2]; e_key[6 * i + 8] = t; \
+ t ^= e_key[6 * i + 3]; e_key[6 * i + 9] = t; \
+ t ^= e_key[6 * i + 4]; e_key[6 * i + 10] = t; \
+ t ^= e_key[6 * i + 5]; e_key[6 * i + 11] = t; \
+}
+
+#define loop8(i) \
+{ t = ls_box(rotr(t, 8)) ^ rco_tab[i]; \
+ t ^= e_key[8 * i]; e_key[8 * i + 8] = t; \
+ t ^= e_key[8 * i + 1]; e_key[8 * i + 9] = t; \
+ t ^= e_key[8 * i + 2]; e_key[8 * i + 10] = t; \
+ t ^= e_key[8 * i + 3]; e_key[8 * i + 11] = t; \
+ t = e_key[8 * i + 4] ^ ls_box(t); \
+ e_key[8 * i + 12] = t; \
+ t ^= e_key[8 * i + 5]; e_key[8 * i + 13] = t; \
+ t ^= e_key[8 * i + 6]; e_key[8 * i + 14] = t; \
+ t ^= e_key[8 * i + 7]; e_key[8 * i + 15] = t; \
+}
+
+rijndael_ctx *
+rijndael_set_key(rijndael_ctx *ctx, const u4byte *in_key, const u4byte key_len,
+ int encrypt)
+{
+ u4byte i, t, u, v, w;
+ u4byte *e_key = ctx->e_key;
+ u4byte *d_key = ctx->d_key;
+
+ ctx->decrypt = !encrypt;
+
+ if(!tab_gen)
+ gen_tabs();
+
+ ctx->k_len = (key_len + 31) / 32;
+
+ e_key[0] = in_key[0]; e_key[1] = in_key[1];
+ e_key[2] = in_key[2]; e_key[3] = in_key[3];
+
+ switch(ctx->k_len) {
+ case 4: t = e_key[3];
+ for(i = 0; i < 10; ++i)
+ loop4(i);
+ break;
+
+ case 6: e_key[4] = in_key[4]; t = e_key[5] = in_key[5];
+ for(i = 0; i < 8; ++i)
+ loop6(i);
+ break;
+
+ case 8: e_key[4] = in_key[4]; e_key[5] = in_key[5];
+ e_key[6] = in_key[6]; t = e_key[7] = in_key[7];
+ for(i = 0; i < 7; ++i)
+ loop8(i);
+ break;
+ }
+
+ if (!encrypt) {
+ d_key[0] = e_key[0]; d_key[1] = e_key[1];
+ d_key[2] = e_key[2]; d_key[3] = e_key[3];
+
+ for(i = 4; i < 4 * ctx->k_len + 24; ++i) {
+ imix_col(d_key[i], e_key[i]);
+ }
+ }
+
+ return ctx;
+};
+
+/* encrypt a block of text */
+
+#define f_nround(bo, bi, k) \
+ f_rn(bo, bi, 0, k); \
+ f_rn(bo, bi, 1, k); \
+ f_rn(bo, bi, 2, k); \
+ f_rn(bo, bi, 3, k); \
+ k += 4
+
+#define f_lround(bo, bi, k) \
+ f_rl(bo, bi, 0, k); \
+ f_rl(bo, bi, 1, k); \
+ f_rl(bo, bi, 2, k); \
+ f_rl(bo, bi, 3, k)
+
+void
+rijndael_encrypt(rijndael_ctx *ctx, const u4byte *in_blk, u4byte *out_blk)
+{
+ u4byte k_len = ctx->k_len;
+ u4byte *e_key = ctx->e_key;
+ u4byte b0[4], b1[4], *kp;
+
+ b0[0] = in_blk[0] ^ e_key[0]; b0[1] = in_blk[1] ^ e_key[1];
+ b0[2] = in_blk[2] ^ e_key[2]; b0[3] = in_blk[3] ^ e_key[3];
+
+ kp = e_key + 4;
+
+ if(k_len > 6) {
+ f_nround(b1, b0, kp); f_nround(b0, b1, kp);
+ }
+
+ if(k_len > 4) {
+ f_nround(b1, b0, kp); f_nround(b0, b1, kp);
+ }
+
+ f_nround(b1, b0, kp); f_nround(b0, b1, kp);
+ f_nround(b1, b0, kp); f_nround(b0, b1, kp);
+ f_nround(b1, b0, kp); f_nround(b0, b1, kp);
+ f_nround(b1, b0, kp); f_nround(b0, b1, kp);
+ f_nround(b1, b0, kp); f_lround(b0, b1, kp);
+
+ out_blk[0] = b0[0]; out_blk[1] = b0[1];
+ out_blk[2] = b0[2]; out_blk[3] = b0[3];
+};
+
+/* decrypt a block of text */
+
+#define i_nround(bo, bi, k) \
+ i_rn(bo, bi, 0, k); \
+ i_rn(bo, bi, 1, k); \
+ i_rn(bo, bi, 2, k); \
+ i_rn(bo, bi, 3, k); \
+ k -= 4
+
+#define i_lround(bo, bi, k) \
+ i_rl(bo, bi, 0, k); \
+ i_rl(bo, bi, 1, k); \
+ i_rl(bo, bi, 2, k); \
+ i_rl(bo, bi, 3, k)
+
+void
+rijndael_decrypt(rijndael_ctx *ctx, const u4byte *in_blk, u4byte *out_blk)
+{
+ u4byte b0[4], b1[4], *kp;
+ u4byte k_len = ctx->k_len;
+ u4byte *e_key = ctx->e_key;
+ u4byte *d_key = ctx->d_key;
+
+ b0[0] = in_blk[0] ^ e_key[4 * k_len + 24]; b0[1] = in_blk[1] ^ e_key[4 * k_len + 25];
+ b0[2] = in_blk[2] ^ e_key[4 * k_len + 26]; b0[3] = in_blk[3] ^ e_key[4 * k_len + 27];
+
+ kp = d_key + 4 * (k_len + 5);
+
+ if(k_len > 6) {
+ i_nround(b1, b0, kp); i_nround(b0, b1, kp);
+ }
+
+ if(k_len > 4) {
+ i_nround(b1, b0, kp); i_nround(b0, b1, kp);
+ }
+
+ i_nround(b1, b0, kp); i_nround(b0, b1, kp);
+ i_nround(b1, b0, kp); i_nround(b0, b1, kp);
+ i_nround(b1, b0, kp); i_nround(b0, b1, kp);
+ i_nround(b1, b0, kp); i_nround(b0, b1, kp);
+ i_nround(b1, b0, kp); i_lround(b0, b1, kp);
+
+ out_blk[0] = b0[0]; out_blk[1] = b0[1];
+ out_blk[2] = b0[2]; out_blk[3] = b0[3];
+};