hexdump -vC test.bin | head -50
00000000  ff ff ff ff ff ff ff ff  ff ff ff ff ff ff ff ff  |................|
00000010  ff ff ff ff ff ff ff ff  ff ff ff ff ff ff ff ff  |................|
00000020  ff ff ff ff ff ff ff ff  ff ff ff ff ff ff ff ff  |................|
00000030  ff ff ff ff ff ff ff ff  ff ff ff ff ff ff ff ff  |................|
00000040  ff ff ff ff ff ff ff ff  ff ff ff ff ff ff ff ff  |................|
00000050  ff ff ff ff ff ff ff ff  ff ff ff ff ff ff ff ff  |................|
00000060  ff ff ff ff ff ff ff ff  ff ff ff ff ff ff ff ff  |................|
00000070  ff ff ff ff ff ff ff ff  ff ff ff ff ff ff ff ff  |................|
00000080  ff ff ff ff ff ff ff ff  ff ff ff ff ff ff ff ff  |................|
00000090  ff ff ff ff ff ff ff ff  ff ff ff ff ff ff ff ff  |................|
000000a0  ff ff ff ff ff ff ff ff  ff ff ff ff ff ff ff ff  |................|
000000b0  ff ff ff ff ff ff ff ff  ff ff ff ff ff ff ff ff  |................|
000000c0  ff ff ff ff ff ff ff ff  ff ff ff ff ff ff ff ff  |................|
000000d0  ff ff ff ff ff ff ff ff  ff ff ff ff ff ff ff ff  |................|
000000e0  ff ff ff ff ff ff ff ff  ff ff ff ff ff ff ff ff  |................|
000000f0  ff ff ff ff ff ff ff ff  ff ff ff ff 01 00 00 00  |................|
00000100  ff ff ff ff ff ff ff ff  ff ff ff ff ff ff ff ff  |................|
00000110  ff ff ff ff ff ff ff ff  ff ff ff ff ff ff ff ff  |................|
00000120  ff ff ff ff ff ff ff ff  ff ff ff ff ff ff ff ff  |................|
00000130  ff ff ff ff ff ff ff ff  ff ff ff ff ff ff ff ff  |................|
00000140  ff ff ff ff ff ff ff ff  ff ff ff ff ff ff ff ff  |................|
00000150  ff ff ff ff ff ff ff ff  ff ff ff ff ff ff ff ff  |................|
00000160  ff ff ff ff ff ff ff ff  ff ff ff ff ff ff ff ff  |................|
00000170  ff ff ff ff ff ff ff ff  ff ff ff ff ff ff ff ff  |................|
00000180  ff ff ff ff ff ff ff ff  ff ff ff ff ff ff ff ff  |................|
00000190  ff ff ff ff ff ff ff ff  ff ff ff ff ff ff ff ff  |................|
000001a0  ff ff ff ff ff ff ff ff  ff ff ff ff ff ff ff ff  |................|
000001b0  ff ff ff ff ff ff ff ff  ff ff ff ff ff ff ff ff  |................|
000001c0  ff ff ff ff ff ff ff ff  ff ff ff ff ff ff ff ff  |................|
000001d0  ff ff ff ff ff ff ff ff  ff ff ff ff ff ff ff ff  |................|
000001e0  ff ff ff ff ff ff ff ff  ff ff ff ff ff ff ff ff  |................|
000001f0  ff ff ff ff ff ff ff ff  ff ff ff ff ff ff ff ff  |................|
00000200  ff ff ff ff 01 00 00 00  74 65 73 74 20 73 74 72  |........test str|
00000210  69 6e 67 20 66 69 6c 65  20 31 20 63 6f 6e 74 65  |ing file 1 conte|
00000220  6e 74 74 65 73 74 20 73  74 72 69 6e 67 32 ff ff  |nttest string2..|
00000230  ff ff ff ff ff ff ff ff  ff ff ff ff ff ff ff ff  |................|
00000240  ff ff ff ff ff ff ff ff  ff ff ff ff ff ff ff ff  |................|
00000250  ff ff ff ff ff ff ff ff  ff ff ff ff ff ff ff ff  |................|
00000260  ff ff ff ff ff ff ff ff  ff ff ff ff ff ff ff ff  |................|
00000270  ff ff ff ff ff ff ff ff  ff ff ff ff ff ff ff ff  |................|
00000280  ff ff ff ff ff ff ff ff  ff ff ff ff ff ff ff ff  |................|
00000290  ff ff ff ff ff ff ff ff  ff ff ff ff ff ff ff ff  |................|
000002a0  ff ff ff ff ff ff ff ff  ff ff ff ff ff ff ff ff  |................|
000002b0  ff ff ff ff ff ff ff ff  ff ff ff ff ff ff ff ff  |................|
000002c0  ff ff ff ff ff ff ff ff  ff ff ff ff ff ff ff ff  |................|
000002d0  ff ff ff ff ff ff ff ff  ff ff ff ff ff ff ff ff  |................|
000002e0  ff ff ff ff ff ff ff ff  ff ff ff ff ff ff ff ff  |................|
000002f0  ff ff ff ff ff ff ff ff  26 00 00 00 02 00 00 00  |........&.......|
00000300  66 69 6c 65 31 00 00 00  00 00 00 00 00 00 00 00  |file1...........|
00000310  00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00  |................|


hexdump -vC test-chacha20.bin | head -50
00000000  cd 70 fb fe 53 77 54 19  d3 40 9e a5 c1 c8 01 6a  |.p..SwT..@.....j|
00000010  c9 f7 4d b9 22 c2 e9 06  41 08 03 d6 bb a5 37 45  |..M."...A.....7E|
00000020  a6 2a 89 fb 4a 10 65 6a  9b db 0a e1 fe 7c 20 66  |.*..J.ej.....| f|
00000030  b9 1c 3c df 9a 7d ed d0  2c e0 d7 c4 ec 9b 7d 3f  |..<..}..,.....}?|
00000040  8e 4b 81 5a 0c a8 2a c1  ae 50 68 87 56 33 43 e6  |.K.Z..*..Ph.V3C.|
00000050  27 92 53 8a eb 75 39 2d  fa 79 24 10 c2 dd 15 f6  |'.S..u9-.y$.....|
00000060  5c 02 5d ab 8c e4 9b b8  d3 4e 7e 95 28 3d 43 f6  |\.]......N~.(=C.|
00000070  bf 7b f1 3e 65 96 46 5c  50 51 f9 1b a8 b5 15 de  |.{.>e.F\PQ......|
00000080  6c ed b9 14 eb 9d b1 3c  c5 be b2 da c4 5c 87 04  |l......<.....\..|
00000090  1d d5 b5 53 0c c4 df f5  3f 59 6b e4 1e 04 48 cc  |...S....?Yk...H.|
000000a0  91 ed 71 38 3c ba 74 f9  c2 50 f5 82 16 c9 ea 38  |..q8<.t..P.....8|
000000b0  95 07 f4 64 35 e4 2b e1  92 e2 61 e8 b3 f2 33 b3  |...d5.+...a...3.|
000000c0  0d aa b6 7e f0 34 64 ef  95 8e 42 77 16 66 01 22  |...~.4d...Bw.f."|
000000d0  ba 9e 72 2a 1c fc 18 19  a9 1e ad 8e b2 5c 4f 70  |..r*.........\Op|
000000e0  f5 65 9f a9 8d f8 fb d7  ad c7 09 88 ac 6a 9f 30  |.e...........j.0|
000000f0  4e 1c 4a 73 74 ea 54 9d  21 1f 94 9e 88 75 73 a6  |N.Jst.T.!....us.|
00000100  9a d9 50 82 05 8b 36 23  ee b5 b4 26 a3 b7 95 48  |..P...6#...&...H|
00000110  a8 6b 7a 0d 47 92 24 80  ac 45 18 03 6f 16 82 91  |.kz.G.$..E..o...|
00000120  6f 59 f5 b9 73 4e 8f 6b  66 42 7c 8c 12 d6 fb 2a  |oY..sN.kfB|....*|
00000130  a6 0f db cb 9b 12 99 39  b7 1e d1 c5 ad 3a 82 6b  |.......9.....:.k|
00000140  f8 47 6c e3 6c 75 9a 65  be 25 19 2e da 67 97 0a  |.Gl.lu.e.%...g..|
00000150  fc 8f 97 2d a9 fe 57 1d  0a 4a b7 29 fe 24 af c6  |...-..W..J.).$..|
00000160  6c 8b df 4e e3 b7 0a c2  03 6e a9 7d 48 7a 1a 20  |l..N.....n.}Hz. |
00000170  10 94 be 6b 6f 37 e9 90  de 3a a4 dd c4 72 23 86  |...ko7...:...r#.|
00000180  41 a2 68 a3 e3 35 e6 99  20 63 10 17 fe f6 10 c5  |A.h..5.. c......|
00000190  bd 85 f7 69 9d b0 52 61  17 49 0f 4b 03 be 58 66  |...i..Ra.I.K..Xf|
000001a0  7c 0e 39 58 37 df fd d8  e0 ed ee f6 f7 b4 6b 5f  ||.9X7.........k_|
000001b0  cf 0e 5a ba db 46 16 e8  dd c3 27 bf db e4 cf ea  |..Z..F....'.....|
000001c0  e6 07 6d ee 3d 3f 82 8c  6b c2 a4 14 77 d2 bc f9  |..m.=?..k...w...|
000001d0  4f d6 8a cd 3a 9f 0c 6b  6c 20 0c 9f fd 3d d8 2a  |O...:..kl ...=.*|
000001e0  3d 30 28 15 04 1a 55 0a  a2 53 30 a3 54 4c 01 c3  |=0(...U..S0.TL..|
000001f0  25 8e 85 d1 62 4c de 94  64 b5 b1 c7 ca 75 d2 06  |%...bL..d....u..|
00000200  8e 7e 1e c6 33 8d 80 2b  b3 4f f6 8e 1f 34 a2 19  |.~..3..+.O...4..|
00000210  8f 1f 87 d3 b7 40 b3 23  a4 75 25 85 63 ab 35 20  |.....@.#.u%.c.5 |
00000220  9f 5c 27 1b 74 a3 19 24  0b c2 e6 54 4c 26 bf 2a  |.\'.t..$...TL&.*|
00000230  9a ce f3 d8 78 05 ae eb  2f 71 55 ef 58 17 73 23  |....x.../qU.X.s#|
00000240  25 2c c9 42 f8 80 61 28  b5 79 fa 1d ce 65 c4 6f  |%,.B..a(.y...e.o|
00000250  05 30 07 3c 6a fc bd a1  c1 da 06 e7 a7 a1 ee 40  |.0.<j..........@|
00000260  4a cc c1 a5 95 74 ba ad  4b 1a 87 24 1c 2b 59 cf  |J....t..K..$.+Y.|
00000270  ca 2a 70 e3 57 bd 01 60  27 7f 01 1e c3 c4 30 9b  |.*p.W..`'.....0.|
00000280  6a db db 3b 7a a8 33 51  8c 13 47 4c 2c af 30 26  |j..;z.3Q..GL,.0&|
00000290  2a 4e 8a 40 cb b6 12 57  e2 37 94 ab fa d2 73 d1  |*N.@...W.7....s.|
000002a0  1d ad 19 67 9e 78 b5 dc  1f 4d 4f a3 c8 35 96 c8  |...g.x...MO..5..|
000002b0  c9 9c 9c 28 42 60 f7 0e  6d 6c 1e 7b 22 4e 6f af  |...(B`..ml.{"No.|
000002c0  ea 3a 58 f6 b6 00 68 40  a4 39 6d 4f d1 53 0c 01  |.:X...h@.9mO.S..|
000002d0  d2 f0 a9 f2 6e f3 07 e9  aa 84 a7 62 37 43 eb ca  |....n......b7C..|
000002e0  46 d3 c9 c8 3c e0 21 1b  61 cb 4e 76 6b 70 6e b8  |F...<.!.a.Nvkpn.|
000002f0  52 4d 9a ee a4 e6 58 26  e8 0f 69 76 2f 1f 02 1b  |RM....X&..iv/...|
00000300  15 65 fa e9 4b e2 a4 16  3f 69 4c 2a d5 8a c9 0d  |.e..K...?iL*....|
00000310  ce 63 1b 1e 69 4f 6e 9c  cf bb 21 ef 06 a1 0d 37  |.c..iOn...!....7|