On 2024-04-06 14:23, Theo Buehler wrote:
> On Sat, Apr 06, 2024 at 02:11:36PM +0200, Mischa Peters wrote:
>> 
>> 
>> > On 6 Apr 2024, at 13:07, Theo Buehler <tb@theobuehler.org> wrote:
>> >
>> > 
>> >> -----BEGIN CERTIFICATE-----
>> >> MIICPjCCAeSgAwIBAgIJAOy1+v/+I2WIMAoGCCqGSM49BAMCMDkxCzAJBgNVBAYT
>> >> Ak5MMRQwEgYDVQQKDAtQaGlsaXBzIEh1ZTEUMBIGA1UEAwwLcm9vdC1icmlkZ2Uw
>> >> IhgPMjAxNzAxMDEwMDAwMDBaGA8yMDM4MDExOTAzMTQwN1owPjELMAkGA1UEBhMC
>> >> TkwxFDASBgNVBAoMC1BoaWxpcHMgSHVlMRkwFwYDVQQDDBBlY2I1ZmFmZmZlMjM2
>> >> NTg4MFkwEwYHKoZIzj0CAQYIKoZIzj0DAQcDQgAEAQMY8V0BUIhXtQfAwMPwqH+2
>> >> EyYnNCo9QhpPN93bJIWjppu0DyVUBzXY6rCyMD506mtSN4EsqH/3SHSPKnKD8KOB
>> >> yzCByDAMBgNVHRMBAf8EAjAAMA4GA1UdDwEB/wQEAwIHgDATBgNVHSUEDDAKBggr
>> >> BgEFBQcDATAdBgNVHQ4EFgQU1s7ZbOFXYZSJLKhsXrPY072icg4wdAYDVR0jBG0w
>> >> a4AUZ2ONTFrDT6o8ItRnKfqWKnHFGmShPaQ7MDkxCzAJBgNVBAYTAk5MMRQwEgYD
>> >> VQQKDAtQaGlsaXBzIEh1ZTEUMBIGA1UEAwwLcm9vdC1icmlkZ2WCFDuxUi22sYpL
>> >> lwJY81Wrqy11phcOMAoGCCqGSM49BAMCA0gAMEUCIQCdQ2Sfn2t+OBGzDkB59OQO
>> >> 6YWwvJ66Q/VZoOyQaCsd3QIgNxpIOEJK3Tk3NTTfCkQOB+vTm285dgGNQ+5Ps3EL
>> >> Ni4=
>> >> -----END CERTIFICATE-----
>> >
>> > This cert is malformed (as is the CA cert that sthen dug up).
>> > The notBefore and notAfter are before 2050:
>> >
>> > $ openssl x509 -in /tmp/ku.pem -dates -noout
>> > notBefore=Jan  1 00:00:00 2017 GMT
>> > notAfter=Jan 19 03:14:07 2038 GMT
>> >
>> > This means they should be encoded as UTCTime per RFC 5280. However,
>> > they are encoded as a GeneralizedTime:
>> >
>> > $ openssl asn1parse -i -in /tmp/ku.pem | grep GEN
>> >  97:d=3  hl=2 l=  15 prim:    GENERALIZEDTIME   :20170101000000Z
>> > 114:d=3  hl=2 l=  15 prim:    GENERALIZEDTIME   :20380119031407Z
>> >
>> > The cryptic error is unfortunate. As a consequence of the following
>> > commit, x509_verify_cert_info_populate() (which would silently cache
>> > nonsense previously) results in EXFLAG_INVALID being set on the cert's
>> > extension flags:
>> >
>> > https://github.com/openbsd/src/commit/91b40737dd8713c4b24d6504eacee31f6b57e4c1
>> >
>> > This in turn leads to an X509_get_key_usage() failure, which in turn
>> > leads to ssl_check_srvr_ecc_cert_and_alg() deciding the certificate
>> > is not for signing.
>> >
>> > Since it is malformed, it is arguably not good for signing. I'm not
>> > sure whether 'ftp -S dont' should imply that the cert is completely
>> > ignored.
>> 
>> The fact it’s malformed doesn’t help. :(
> 
> I explained what fails and where.
> 
>> I am seeing the same with Perl and Net-SSLeay, which was working on 
>> 7.4 and no longer on 7.5.
>> 
>> What would be the best course of action to take with destinations like 
>> this? Especially since I can’t control the other side.
> 
> I would try this diff first:
> 
> Index: ssl_lib.c
> ===================================================================
> RCS file: /cvs/src/lib/libssl/ssl_lib.c,v
> diff -u -p -r1.322 ssl_lib.c
> --- ssl_lib.c	27 Mar 2024 06:47:52 -0000	1.322
> +++ ssl_lib.c	6 Apr 2024 12:23:04 -0000
> @@ -2328,7 +2328,7 @@ ssl_check_srvr_ecc_cert_and_alg(SSL *s,
> 
>  	alg_a = cs->algorithm_auth;
> 
> -	if (alg_a & SSL_aECDSA) {
> +	if (0 && (alg_a & SSL_aECDSA)) {
>  		/* Key usage, if present, must allow signing. */
>  		if (!(X509_get_key_usage(x) & X509v3_KU_DIGITAL_SIGNATURE)) {
>  			SSLerror(s, SSL_R_ECC_CERT_NOT_FOR_SIGNING);

Thank Theo! Patching against -stable gives me:

root@m720q:/usr/src/lib/libssl # patch < /home/mischa/ssl-patch-1.txt
Hmm...  Looks like a unified diff to me...
The text leading up to this was:
--------------------------
|Index: ssl_lib.c
|===================================================================
|RCS file: /cvs/src/lib/libssl/ssl_lib.c,v
|diff -u -p -r1.322 ssl_lib.c
|--- ssl_lib.c    27 Mar 2024 06:47:52 -0000    1.322
|+++ ssl_lib.c    6 Apr 2024 12:23:04 -0000
--------------------------
Patching file ssl_lib.c using Plan A...
Hunk #1 failed at 2328.
1 out of 1 hunks failed--saving rejects to ssl_lib.c.rej
Hmm...  Ignoring the trailing garbage.
done

I did change the line manually and we have success!

root@m720q:~ # ftp https://10.0.0.51/api
Trying 10.0.0.51...
TLS handshake failure: certificate verification failed: unable to get 
local issuer certificate
root@m720q:~ # ^C
root@m720q:~ # ftp -Sdont https://10.0.0.51/api
Trying 10.0.0.51...
Requesting https://10.0.0.51/api
95 bytes received in 0.00 seconds (279.69 KB/s)

Mischa