The following uses the aes256-ctr/bcrypt encryption. The passphrase is "test".

The new "v1" format contains the header "-----BEGIN OPENSSH PRIVATE KEY-----"
and the footer "-----END OPENSSH PRIVATE KEY-----".

All length ints are uint32, network-byte order.

PEM:
-----BEGIN OPENSSH PRIVATE KEY-----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-----END OPENSSH PRIVATE KEY-----

HEX:

ANNOTATED HEX:
0 6f70656e7373682d6b65792d763100 ("openssh-key-v1" + 0x00)
00000004  4
6e6f6e65  "none"
00000004  4
6e6f6e65  "none"
00000000  0

00000001  1
00000217  535
00000007  7
7373682d727361  "ssh-rsa"
00000003  3
010001  65537
00000201  513
00b7cec04601ce2a12f0c924cb9a30eb990066812cb14369193f30b2b9fdd4afcb300c918f2a77d6
4410f3617ae7c8ca318c257d3c4df4e2c4108bbbe93a86894ba14b3575f2f72150bc381dcbfb742c
7a196866fd3184ace96761adda0fc2992f6c866d7569919fc22d9c4bf0de405a8c76d519aa2a5329
dc6825777229a5d0b753a7825a89b95275f9c025e215343c6c88cd6690a221f8ae9ef675ee464dc7
d118da410507ea5d6b6489dd60afd8a6646492db3e279f1a78240db8abbda6c50714c9636650a720
81e7fa5d472c1428b07eae5d15b64ea1e2a7508512fe9ab655f86a313486d3cca1dd8e90acc5c9fb
a4d6e767507fbab9f3a7f68c748142af2a3701d31a8a9b7511958aa77187ba702ed934d385afcee4
2380e95e0e7e9bc0f4d23367fc770374167b7f0926fb6fdb6d05aad1cfd191824845b014e18153bf
0d1d3c3b1fadbb25a3f1d151f9b684633d8c1690fcd8cad05aac2aeb23dbf19a37e480a008910319
c116d47bd924b39942543b88a0f6127952b2d8e1290f3029f542aebe9c0c8e36cf3296865cd6643c
8924d566ebf4971809399a1ac096fe1edc3b5f871bf5ef0b4d44e0ea27620d205142e0bfcf677b4d
b025532121a3f0745aa4d0586331733257855a5cecbe3ac4403d04ff0cc0c58b7c04904b402125c2
bc2a63a20ebb309cc6f3e65db301a058b8dace07e71b38f3f3595433f69b198f07
00000750  1872
53834712  checksum
53834712  checksum
00000007  7
7373682d727361  "ssh-rsa"
00000201  513
00b7cec04601ce2a12f0c924cb9a30eb990066812cb14369193f30b2b9fdd4afcb300c918f2a77d6  pubkey
4410f3617ae7c8ca318c257d3c4df4e2c4108bbbe93a86894ba14b3575f2f72150bc381dcbfb742c
7a196866fd3184ace96761adda0fc2992f6c866d7569919fc22d9c4bf0de405a8c76d519aa2a5329
dc6825777229a5d0b753a7825a89b95275f9c025e215343c6c88cd6690a221f8ae9ef675ee464dc7
d118da410507ea5d6b6489dd60afd8a6646492db3e279f1a78240db8abbda6c50714c9636650a720
81e7fa5d472c1428b07eae5d15b64ea1e2a7508512fe9ab655f86a313486d3cca1dd8e90acc5c9fb
a4d6e767507fbab9f3a7f68c748142af2a3701d31a8a9b7511958aa77187ba702ed934d385afcee4
2380e95e0e7e9bc0f4d23367fc770374167b7f0926fb6fdb6d05aad1cfd191824845b014e18153bf
0d1d3c3b1fadbb25a3f1d151f9b684633d8c1690fcd8cad05aac2aeb23dbf19a37e480a008910319
c116d47bd924b39942543b88a0f6127952b2d8e1290f3029f542aebe9c0c8e36cf3296865cd6643c
8924d566ebf4971809399a1ac096fe1edc3b5f871bf5ef0b4d44e0ea27620d205142e0bfcf677b4d
b025532121a3f0745aa4d0586331733257855a5cecbe3ac4403d04ff0cc0c58b7c04904b402125c2
bc2a63a20ebb309cc6f3e65db301a058b8dace07e71b38f3f3595433f69b198f07
00000003  3
010001  65537
00000200  512
499f2c705e04bfe17a4476d27e5e1ddfd8c335f63ac22f748754f02183440f6da93f3f8642926166  private key?
3e0bddfda69d4c2f705d0bbe7dd31a8941bf5672e29844a1e0670970c6f2a98b76f85b26fafedb59
c49786b8df7eaeeb86171fd579fe8df0eadd2536a4244a0332d5a9ad3eb8340c930464153e82b4ff
ad4f647a7ba808e3854450f806b60e0b670fc99cb6b58786497d4c199e7750ee5089934eef25f465
12394955c487e10744ebdb9a00951c8095b024d4ce75f1da3146b5b3447169f59e23d40685438bc7
bcad1173927a389a0903ba111a46809d123b3432197cca8fc0c27816fbf215c2b7c584b94f37c9ed
8a8e815942effdcf54757268afe58fd700cdcf6a98a20950617b0624aa835d95e27d7afcdee70c39
7ca1b6aa04735e6d5c5e01bfff2174cf562d36842624490e12ca8142595d52567494f38b2124012c
acacb2564e21c845eb94f5d6ebf6f39066e1fa04b318174e6f9994823ba4d9ef2c28b37cb3ea05fa
3cad7200898394276835523e4e416054f23db0eb732211d3a11ea551390ae8d58d69e14664e0e20f
2bf0ccd24d260b832a94144f5801ea7cdbb2436f21ba2dbaecbcd573f24c5e0d43fd26b4ae6764e1
38ddaf4775ac0163e45727c10027f716cbe3cc70fff73441bb2538e5426a1a5638b448a7bde96804
1ec2184ef67b0da60070297cd73deeefebd1951611c7a776c956e18e5f163a21
00000100  256  (768 total)
0ae2e1cf2455a0d82272e6a42bbba83eb765496e5a33e13b8c94756d8c32f7d7505fd997bdd5ec08  private key?
c59bf8d1d659d1df02bec669ebb5aaaf5db1ec70ce2f2a6b3a17b7b1fce3adc6203c2905cd652d76
22065dd011ae33894467c6dca3643952b0caedff9bc78ac40408074027566ee4c4751ad3ff452a27
81af8b5c2c9bf09b34ee5e6201330b4bc381af766798667c5b9ad0733c19f4ef475fd264655e0305
53f2f2f8de59c2aee74b9dd6720e3108143dfedd41cf4bc11de2b9a9f40faec72a52312abee4c615
5acfee9384a16348c715346ebe693895fe6d2348d4dedb0a137c487185ff949c209115b9c8a10632
9991f049e8430c7ba60dd5408d72ac98
00000101  257  (1025)
00e50b65ba6ae4cb29ae66129c3e41ffeba36cd6ecbaa7045ff90cea71d09bc056b0b9134dc5754c  private key?
49da1fe8ab169cd149eedaeccf4913d915f4f241c5fd86c77511e0c261c344600a84cce78e8cf493
e492844cb82c42ab6d1246a53e5cf50ad4759c2a5c09d53b1c5c3b449328eea01434d6e537b3a513
928dfaddf0a7272823899b8d795220cb3344ab8d0e846e1e40ffdfb5c719262c2b527a890a51faab
cf10904699135f7b997487f4b48d4490ad80fc25b346fa0bb587f09295bf0f71ac10a8086867d4ba
d00a0c27a6456f08e0c2bf8caed8768f0366a2440428180a292617af61feabab9a7075b8bc21209a
5439bbfe3613917071fee74a8d5d80fe99
00000101  257  (1282)
00cd7077659fad983104bcc7dc526242b9ea52cea40e923df771ac2a28e377f2b9231a58c2448c6b  private key?
8d17fe83571ef6bdbbc11f3d4ab4254ea859684b8772911f9c6f355479053e3e3d3a6ecce13a0169
08298ca3f8b628d2111749a3627628eb05844f546795a5067d39b1d304e19cc6fc1be00a6164ea33
e4abbc87f56832271d825c868c5ccda3775b037711e99436f96c53f3780b985084e1d84a458c687a
b0938a09bf6f9b3ffec41ed02fd5b27572c7d180039e405a559b62fc08f804b19f043dba4c6f7565
b1c72759f4b932d4f93d4f41da91b1b146f29854a1008341e4760bdd4987097ec4a6551ab96e099a
04a38d6a893b533db185abb55736419e9f
00000018  24
54686973206973206120636f6d6d656e7420737472696e67  "This is a comment string"
010203  (padding)