JSON Web Key (JWK) for public key requires x and y coordinates.

[Douglas Morris]

Hello,
Not a genius with openssl or encryption at all. Thanks for reading.
Background:

* Generate a private key (really key set) with named curve:openssl genpkey -algorithm EC -pkeyopt ec_paramgen_curve:prime256v1 -pkeyopt ec_param_enc:named_curve -outform PEM -out account-privkey-prime256v1.pem
* Look at named curves representation:openssl pkey -in account-privkey-prime256v1.pem -noout -text
* Look at explicit encoding ( I want x and y coordinates ):openssl ec -in  account-privkey-prime256v1.pem -param_enc explicit -text -noout
Example output:read EC key
Private-Key: (256 bit)
priv:
    ae:b7:b9:30:ed:3d:2f:03:b9:0c:bd:b8:39:b9:5c:
    39:33:c0:48:f1:45:a2:b4:8a:1b:4c:8c:86:f0:86:
    2a:5a
pub:
    04:68:1f:bc:7f:2b:c8:c3:c1:4d:5e:b1:2c:b5:29:
    62:d7:01:21:51:70:bc:e5:30:ab:10:96:c8:23:0a:
    7b:df:85:00:7b:fb:bb:58:4d:e6:4a:80:a6:ef:a1:
    be:df:72:08:48:e0:3c:13:d4:7d:f8:62:75:d0:d8:
    b5:aa:c2:b3:c1
Field Type: prime-field
Prime:
    00:ff:ff:ff:ff:00:00:00:01:00:00:00:00:00:00:
    00:00:00:00:00:00:ff:ff:ff:ff:ff:ff:ff:ff:ff:
    ff:ff:ff
A:   
    00:ff:ff:ff:ff:00:00:00:01:00:00:00:00:00:00:
    00:00:00:00:00:00:ff:ff:ff:ff:ff:ff:ff:ff:ff:
    ff:ff:fc
B:   
    5a:c6:35:d8:aa:3a:93:e7:b3:eb:bd:55:76:98:86:
    bc:65:1d:06:b0:cc:53:b0:f6:3b:ce:3c:3e:27:d2:
    60:4b
Generator (uncompressed):
    04:6b:17:d1:f2:e1:2c:42:47:f8:bc:e6:e5:63:a4:
    40:f2:77:03:7d:81:2d:eb:33:a0:f4:a1:39:45:d8:
    98:c2:96:4f:e3:42:e2:fe:1a:7f:9b:8e:e7:eb:4a:
    7c:0f:9e:16:2b:ce:33:57:6b:31:5e:ce:cb:b6:40:
    68:37:bf:51:f5
Order: 
    00:ff:ff:ff:ff:00:00:00:00:ff:ff:ff:ff:ff:ff:
    ff:ff:bc:e6:fa:ad:a7:17:9e:84:f3:b9:ca:c2:fc:
    63:25:51
Cofactor:  1 (0x1)
Seed:
    c4:9d:36:08:86:e7:04:93:6a:66:78:e1:13:9d:26:
    b7:81:9f:7e:90

* RFC7518, sec. 6.2.1 requires for public key representation key-value pairs for keys 'crv', 'x', and 'y'.The 'crv' value is easy. It's the line NIST CURVE: P-256 from the -text for named curve format, not shown above.The 'x' and the 'y' are not shown. My guess from looking online is that x and y are in the value for openssl -textvalue 'pub'. In output above, pub value (abbreviated) is 04:68...b3:c1. I have not been successful in unpackingthe pub value to show anything coherent. I think the colons can be dropped and what's left can be decodedbase64 or base64url. My openssl (Debian linux) has no 'base64' subcommand.
I have found nothing online about this. I figure this should be important. Typically, lack of relevant documentation online means I am making a very original mistake. I am not subscribed to the openssl-users at openssl.org mailing list. I can of course checkthe archives and see if this went into it.
What am I doing wrong? I think it's a conceptual thing. I am not a C programmer and don't exactly want to figure out how to use the C functions. Even so, I am interested in what's a reasonable  approach, even if not so reasonable for me. I must be doing something unreasonable. Thanks. Happy Holidays if that applies to you.
Bonus Question: Do I or should I worry about seeding for the Pseudorandom Number Generator (PRNG). It seems to me that it would be nice to get a pseudo-random number and just mess it up a bit in a text editor and use that as the seed for making a new key. Just a guess. If you have an informed thought on that, I'd be interested.

Thanks for openssl and everything! It's indispensible free software.

Douglas Morris
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