Code change:
} // exampleCert was generated from crypto/tls/generate_cert.go with the following command: <del> //    go run generate_cert.go  --rsa-bits 512 --host example.com --ca --start-date "Jan 1 00:00:00 1970" --duration=1000000h </del> <ins> //    go run generate_cert.go  --rsa-bits 1024 --host example.com --ca --start-date "Jan 1 00:00:00 1970" --duration=1000000h </ins> var exampleCert = []byte(`-----BEGIN CERTIFICATE----- <del> MIIBdzCCASGgAwIBAgIRAOVTAdPnfbS5V85mfS90TfIwDQYJKoZIhvcNAQELBQAw EjEQMA4GA1UEChMHQWNtZSBDbzAgFw03MDAxMDEwMDAwMDBaGA8yMDg0MDEyOTE2 MDAwMFowEjEQMA4GA1UEChMHQWNtZSBDbzBcMA0GCSqGSIb3DQEBAQUAA0sAMEgC QQCoVSqeu8TBvF+70T7Jm4340YQNhds6IxjRoifenYodAO1dnKGrcbF266DJGunh nIjQH7B12tduhl0fLK4Ezf7/AgMBAAGjUDBOMA4GA1UdDwEB/wQEAwICpDATBgNV HSUEDDAKBggrBgEFBQcDATAPBgNVHRMBAf8EBTADAQH/MBYGA1UdEQQPMA2CC2V4 YW1wbGUuY29tMA0GCSqGSIb3DQEBCwUAA0EAk1kVa5uZ/AzwYDVcS9bpM/czwjjV xq3VeSCfmNa2uNjbFvodmCRwZOHUvipAMGCUCV6j5vMrJ8eMj8tCQ36W9A== </del> <ins> MIIB+zCCAWSgAwIBAgIQK+TtYrwiS4SZU43mEj44eDANBgkqhkiG9w0BAQsFADAS MRAwDgYDVQQKEwdBY21lIENvMCAXDTcwMDEwMTAwMDAwMFoYDzIwODQwMTI5MTYw MDAwWjASMRAwDgYDVQQKEwdBY21lIENvMIGfMA0GCSqGSIb3DQEBAQUAA4GNADCB iQKBgQDGrjJJBajkyWUEMVwVadkNI54cKV7snXFV6ZRE2jPQUpY0/6a2RKqjGekB +SKxN+ALY/WiPBkYCQVg7Bc1hFneHfR8T3oXlKpOv9VWMeKLH3vLmAKnrZHgBgZ3 jVcXupQlVLobRzABzfOFhhzMcs89vzbMDcxw+tRK84XYB+MNbwIDAQABo1AwTjAO BgNVHQ8BAf8EBAMCAqQwEwYDVR0lBAwwCgYIKwYBBQUHAwEwDwYDVR0TAQH/BAUw AwEB/zAWBgNVHREEDzANggtleGFtcGxlLmNvbTANBgkqhkiG9w0BAQsFAAOBgQCJ uqAiZIaaz5W2dbIUHnWJ3M47fuou8G2c4JzxPRfKxPGrOpBGZyk/I8v/MBZ50zdG ZCoFO0keiVr0q2fyMgKwcWNN4cwfRBgQWmk6SHJJR/jWHjnvnRDqhfPHzcqYqd90 MtpcamlkHhSG616mBaUujb+EdjlrxCwiPTv/U+z7Ug== </ins> -----END CERTIFICATE-----`) var exampleKey = []byte(`-----BEGIN RSA PRIVATE KEY----- <del> MIIBOgIBAAJBAKhVKp67xMG8X7vRPsmbjfjRhA2F2zojGNGiJ96dih0A7V2coatx sXbroMka6eGciNAfsHXa126GXR8srgTN/v8CAwEAAQJASdzdD7vKsUwMIejGCUb1 fAnLTPfAY3lFCa+CmR89nE22dAoRDv+5RbnBsZ58BazPNJHrsVPRlfXB3OQmSQr0 SQIhANoJhs+xOJE/i8nJv0uAbzKyiD1YkvRkta0GpUOULyAVAiEAxaQus3E/SuqD P7y5NeJnE7X6XkyC35zrsJRkz7orE8MCIHdDjsI8pjyNDeGqwUCDWE/a6DrmIDwe emHSqMN2YvChAiEAnxLCM9NWaenOsaIoP+J1rDuvw+4499nJKVqGuVrSCRkCIEqK 4KSchPMc3x8M/uhw9oWTtKFmjA/PPh0FsWCdKrEy </del> <ins> MIICeAIBADANBgkqhkiG9w0BAQEFAASCAmIwggJeAgEAAoGBAMauMkkFqOTJZQQx XBVp2Q0jnhwpXuydcVXplETaM9BSljT/prZEqqMZ6QH5IrE34Atj9aI8GRgJBWDs FzWEWd4d9HxPeheUqk6/1VYx4osfe8uYAqetkeAGBneNVxe6lCVUuhtHMAHN84WG HMxyzz2/NswNzHD61ErzhdgH4w1vAgMBAAECgYEAgv0GGi6pE23UM9d3JocKmycI bvi3pLiIqGO/ZUWXM5m/fmGuwCy1c6L5hFuFC+ISzG+y2qtUwAvyh9wf0SDZPfVK X+egWPJksBCPqphvPsxzolHNoi5FEvUhxXyDedkB3XuP2U3hniwEVtIA/rf1lHLt qMDEa/y4K1GT8QI0Y8ECQQDNl5Zu38BaroOLMpm7XBySlYVp8hs2q4TCnayxufAw wKZJpcTKTCiaZAqF00ZDu2YZ3m3dkDiYB6v3x2HIADVtAkEA92TIYjBy5Bx7+K2S X1YW+7P90UImxXGbPQeoODmghUD+/MfnBQyKM7AS7G2jO81hwzGfFiKk7AqF/nM5 lx1wywJANjoTfa8ax1Bcdeyky9xh1PAHPoiTUPowjDyWflIy3kkSEz7cBxfLZd2Z QO8XC2p0ZcJbbCNMKh1r6HD4g446iQJBANOMKdHUzhoDxXrTqcu+SS75Lf0HzTGf QPkCGDXkCUCJYMH1irYFkBQ85yGnayMTMBsCzp/WBiMVqJj6HO/8q9sCQQCxtTUn rOjiKXcyl2aNL7bGLfWtexl+MT2Z/PrjYcN5XbK4wmy2TFUAA1BCyHhv1/1jUDzf Ibw/Lq9YIiqVrg6T </ins> -----END RSA PRIVATE KEY-----`)

Related discussion:
text: Golang 1.13 uses TLS 1.13 by default (opt-out), which introduces RSA-PSS. RSA-PSS does not work with keys that are too small. The issue was uncovered during Fedora mass rebuild which uses Golang 1.13: See /sig api-machinery
What is the failure mode if a smaller key is used?
/sig auth /sig scalability
/sub