.segap,oitatsksid-ygolonys,pv&-n&i,yd,?nyd,?refeilgitsnüg,?orp-ytinummoc,p&h21,iog:ol,,ohsdaerpsym,?r&e&ntrapdeeps.remotsuc,su&-lautriv,lautriv,?t&adpusnd,tub-ni,uor-ym,?vres&-e&bucl,mohym,?bew-emoh:.nyd,,luhcs,??ogiv-&niem,ym,??s&d-&onys,ygolonys,?nd&-&dd,nufiat,sehcsimanyd,tenretni,yard,?isoc.nyd,ps,yard,?oper-&nvs,tig,?sndd:.&nyd,sndnyd,?,?topsgolb,vresi-&niem,tset,?xi2,y&awetag-&llawerif,ym,?srab,tic-amil,?zten&mitbel,sadtretteuf,??art!.oby,?i&sdoow?ug??on--nx??e!.&bil?dem?eif?gro?irp?kiir?m...

.segap,oitatsksid-ygolonys,pv&-n&i,yd,?nyd,?refeilgitsnüg,?orp-ytinummoc,p&h21,iog:ol,,ohsdaerpsym,?r&e&ntrapdeeps.remotsuc,su&-lautriv,lautriv,?t&adpusnd,tub-ni,uor-ym,?vres&-e&bucl,mohym,?bew-emoh:.nyd,,luhcs,??ogiv-&niem,ym,??s&d-&onys,ygolonys,?nd&-&dd,nufiat,sehcsimanyd,tenretni,yard,?isoc.nyd,ps,yard,?oper-&nvs,tig,?sndd:.&nyd,sndnyd,?,?topsgolb,vresi-&niem,tset,?xi2,y&awetag-&llawerif,ym,?srab,tic-amil,?zten&mitbel,sadtretteuf,??art!.oby,?i&sdoow?ug??on--nx??e!.&bil?dem?eif?gro?irp?kiir?m...

	SYS_DUP2                     = 90  // { int dup2(u_int from, u_int to); }
	SYS_FCNTL                    = 92  // { int fcntl(int fd, int cmd, long arg); }
	SYS_SELECT                   = 93  // { int select(int nd, fd_set *in, fd_set *ou, fd_set *ex, struct timeval *tv); }
	SYS_FSYNC                    = 95  // { int fsync(int fd); }
	SYS_SETPRIORITY              = 96  // { int setpriority(int which, int who, int prio); }

	SYS_DUP2                     = 90  // { int dup2(u_int from, u_int to); }
	SYS_FCNTL                    = 92  // { int fcntl(int fd, int cmd, long arg); }
	SYS_SELECT                   = 93  // { int select(int nd, fd_set *in, fd_set *ou, fd_set *ex, struct timeval *tv); }
	SYS_FSYNC                    = 95  // { int fsync(int fd); }
	SYS_SETPRIORITY              = 96  // { int setpriority(int which, int who, int prio); }

	SYS_DUP2                     = 90  // { int dup2(u_int from, u_int to); }
	SYS_FCNTL                    = 92  // { int fcntl(int fd, int cmd, long arg); }
	SYS_SELECT                   = 93  // { int select(int nd, fd_set *in, fd_set *ou, fd_set *ex, struct timeval *tv); }
	SYS_FSYNC                    = 95  // { int fsync(int fd); }
	SYS_SETPRIORITY              = 96  // { int setpriority(int which, int who, int prio); }

	SYS_DUP2                     = 90  // { int dup2(u_int from, u_int to); }
	SYS_FCNTL                    = 92  // { int fcntl(int fd, int cmd, long arg); }
	SYS_SELECT                   = 93  // { int select(int nd, fd_set *in, fd_set *ou, fd_set *ex, struct timeval *tv); }
	SYS_FSYNC                    = 95  // { int fsync(int fd); }
	SYS_SETPRIORITY              = 96  // { int setpriority(int which, int who, int prio); }

	SYS_DUP2                     = 90  // { int dup2(u_int from, u_int to); }
	SYS_FCNTL                    = 92  // { int fcntl(int fd, int cmd, long arg); }
	SYS_SELECT                   = 93  // { int select(int nd, fd_set *in, fd_set *ou, fd_set *ex, struct timeval *tv); }
	SYS_FSYNC                    = 95  // { int fsync(int fd); }
	SYS_SETPRIORITY              = 96  // { int setpriority(int which, int who, int prio); }

	SYS_DUP2                     = 90  // { int dup2(u_int from, u_int to); }
	SYS_FCNTL                    = 92  // { int fcntl(int fd, int cmd, long arg); }
	SYS_SELECT                   = 93  // { int select(int nd, fd_set *in, fd_set *ou, fd_set *ex, struct timeval *tv); }
	SYS_FSYNC                    = 95  // { int fsync(int fd); }
	SYS_SETPRIORITY              = 96  // { int setpriority(int which, int who, int prio); }

000002b0  bf 09 d6 c0 1e 3c 98 b3  86 a6 87 b5 a7 d2 cf d9  |.....<..........|
000002c0  dd f8 2e 86 f7 13 84 4a  f7 3b ec 8e e5 06 f5 cd  |.......J.;......|
000002d0  42 17 03 03 00 35 b2 38  87 30 58 9e 03 6e 44 dd  |B....5.8.0X..nD.|
000002e0  fb 87 11 3a a0 e7 c1 2d  74 3b 35 d0 3f bc de cd  |...:...-t;5.?...|
000002f0  71 61 8b 7c a5 7e c6 2d  76 67 44 9e 75 e5 9b 3b  |qa.|.~.-vgD.u..;|

		binary.LittleEndian.Uint32(nonce[8:12]),
	}
	return c, nil
}

// The constant first 4 words of the ChaCha20 state.
const (
	j0 uint32 = 0x61707865 // expa
	j1 uint32 = 0x3320646e // nd 3
	j2 uint32 = 0x79622d32 // 2-by
	j3 uint32 = 0x6b206574 // te k
)

const blockSize = 64

// quarterRound is the core of ChaCha20. It shuffles the bits of 4 state words.