Curl POST request in Bash removing characters in API call - bash

Question

I am trying to post a public key from a server with Bash to Github as part of an automation set-up. I am using cURL for that like so:
# Make API call to Github
api_token="some string"
pub_key="$(cat /home/${project_name}/.ssh/id_rsa.pub)"
echo $pub_key
curl -H "Authorization: token ${api_token}" -H "Content-Type: application/json" -X POST -d '{"title":"'"$project_name"'","key":"'"$pub_key"'"}' https://api.github.com/user/keys
As you can see I echo the pub_key just to make sure its getting it correctly, this is the output and the result of the API call to Github:
ssh-rsa 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 stackoverflowtest#rasenberg
{
"id": 46506612,
"key": "ssh-rsa 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",
"url": "https://api.github.com/user/keys/46506612",
"title": "stackoverflowtest",
"verified": true,
"created_at": "2020-09-27T04:23:30Z",
"read_only": false
}
As you can see in the API call, Curl cuts of the = stackoverflowtest#rasenberg part at the end, and therefore I post an invalid pub key to Github, resulting it in not working. What is going wrong?

Answer 1

As https://stackoverflow.com/users/3266847/benjamin-w commented (!), the comment portion of an OpenSSH-format pubkey is optional and not needed, and was almost certainly removed by github (after receipt) not by curl. However, your key is in fact invalid and I'm a bit surprised github considers it verified.
$ printf 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 |openssl base64 -d -A|od -Ax -tx1
000000 00 00 00 07 73 73 68 2d 72 73 61 00 00 00 03 01
000010 00 01 00 00 01 81 00 e2 eb 6c 79 99 a4 76 53 8d
000020 be 6a c7 5d 0d 21 77 db 67 6c 76 48 d3 35 e1 ba
000030 f5 0b d5 dd ca ce 78 38 23 89 96 49 4c 2c 2a a3
000040 19 24 f6 50 db 7e 47 f2 71 2e 90 05 ac c0 f1 c3
000050 ef e2 c7 31 2f 52 b5 6d 68 17 43 aa 7c ff d4 d6
000060 3f cf 7f a1 42 5c 7f e0 bd f9 b3 33 20 59 89 ea
000070 33 86 03 68 a4 03 4f 8a ea 5e c6 af 86 3b 49 94
000080 7d 52 e7 2d 6b 01 51 e7 ab c5 a9 68 fd 60 45 bb
000090 26 10 50 11 51 12 f5 33 5b f9 62 4b 67 a4 0f c2
0000a0 5f 8f 69 33 ad ff a4 17 22 fa e7 87 47 df 23 9b
0000b0 ae 4e 43 20 d6 6e d7 18 c3 6e 4e 70 67 1d 86 b6
0000c0 39 0d 06 21 f2 f4 cc 6f 02 12 a2 d6 72 1e 00 90
0000d0 fd a0 90 13 85 1f 72 e7 23 0b 9c 4b 4d 22 8b dc
0000e0 69 3d 50 4b 46 fe 4e e5 60 87 33 d9 ba 03 b4 6d
0000f0 1e d2 b2 10 bb b9 67 a2 0e b4 b5 47 0b a4 91 3e
000100 75 5d 51 ac 38 a0 49 ad dd a7 a4 a8 41 27 5e 4a
000110 b8 26 89 bc 6a ba 62 50 b5 82 60 1f 5d e4 2e 31
000120 e8 21 91 ac aa a8 a6 11 c0 7e e9 a8 40 51 61 e8
000130 63 2d 36 b0 cb 71 51 94 5e 62 1a f2 a6 a9 39 03
000140 6f b1 2c dc 0d e5 64 c8 26 cd bb a4 65 ba bc 32
000150 59 81 bc 30 7e 3c 5c 2a c5 0d 4d cb fa 19 98 a6
000160 d1 84 01 18 06 77 d2 19 49 cb 4c 9e 0f de 95 43
000170 88 cf 50 cb dd 91 87 e3 77 e5 31 e9 57 11 9f 14
000180 9b 2f 2d 02 46 ad ef f4 fc 62 eb bd b5 4f 0d f0
000190 32 aa 29 5d 7a
000195
The length of n, 00 00 01 81 at byte offsets 0x12-0x15, would correspond to a 3072-bit RSA key (with the sign byte required by SSH mpint) but implies the total length of the blob (after base64 decoding, or before encoding) should be 0x197 and instead it's actually 0x195, making it invalid and unusable. Check whatever program or process you used to create this key; there's a bug somewhere.