1This test data was produced by creating a self-signed EC cert using OpenSSL, 2and then extracting the relevant fields. 3 4It uses ECDSA with curve secp384r1 an SHA-256. 5 6(1) Generate self-signed certificate 7 8 openssl ecparam -out ec_key.pem -name secp384r1 -genkey 9 openssl req -new -key ec_key.pem -x509 -nodes -days 365 -out cert.pem 10 11(2) Extract public key 12 13 openssl x509 -in cert.pem -pubkey -noout > pubkey.pem 14 cat pubkey.pem 15 16(3) Extract signed data (tbsCertificate) 17 18 openssl asn1parse -in cert.pem -out tbs -noout -strparse 4 19 base64 tbs 20 21(4) Extract signature algorithm 22 23 # Find the offset of the signature algorithm near the end (496 in this case) 24 openssl asn1parse -in cert.pem 25 26 openssl asn1parse -in cert.pem -out alg -noout -strparse 496 27 base64 alg 28 29(5) Extract the signature 30 31 # Find the final offset of BIT STRING (508 in this case) 32 openssl asn1parse -in cert.pem 33 34 openssl asn1parse -in cert.pem -out sig -noout -strparse 508 35 base64 sig 36 37 38$ openssl asn1parse -i < [PUBLIC KEY] 39 0:d=0 hl=2 l= 118 cons: SEQUENCE 40 2:d=1 hl=2 l= 16 cons: SEQUENCE 41 4:d=2 hl=2 l= 7 prim: OBJECT :id-ecPublicKey 42 13:d=2 hl=2 l= 5 prim: OBJECT :secp384r1 43 20:d=1 hl=2 l= 98 prim: BIT STRING 44-----BEGIN PUBLIC KEY----- 45MHYwEAYHKoZIzj0CAQYFK4EEACIDYgAEXFhBi+WKXuxeK9yCbC9jqEchwjCNsQ4RXAsJ07oHZ+Q 46qz55cNIY5BAhcQ0QYY5jv9BimGL9SuhUuOSuS3Pn9rrsIFGcFsihy4kDr8rq5+7RbN8bV057gW5 47emYjLtvDsQ 48-----END PUBLIC KEY----- 49 50$ openssl asn1parse -i < [ALGORITHM] 51 0:d=0 hl=2 l= 10 cons: SEQUENCE 52 2:d=1 hl=2 l= 8 prim: OBJECT :ecdsa-with-SHA256 53-----BEGIN ALGORITHM----- 54MAoGCCqGSM49BAMC 55-----END ALGORITHM----- 56 57-----BEGIN DATA----- 58MIIB6KADAgECAgkAtUVxft6/Vc0wCgYIKoZIzj0EAwIwbzELMAkGA1UEBhMCQVUxEzARBgNVBAg 59MClNvbWUtU3RhdGUxITAfBgNVBAoMGEludGVybmV0IFdpZGdpdHMgUHR5IEx0ZDEMMAoGA1UEAw 60wDYWhhMRowGAYJKoZIhvcNAQkBFgtzdXBAZm9vLmNvbTAeFw0xNTA3MDIwMDM4MTRaFw0xNjA3M 61DEwMDM4MTRaMG8xCzAJBgNVBAYTAkFVMRMwEQYDVQQIDApTb21lLVN0YXRlMSEwHwYDVQQKDBhJ 62bnRlcm5ldCBXaWRnaXRzIFB0eSBMdGQxDDAKBgNVBAMMA2FoYTEaMBgGCSqGSIb3DQEJARYLc3V 63wQGZvby5jb20wdjAQBgcqhkjOPQIBBgUrgQQAIgNiAARcWEGL5Ype7F4r3IJsL2OoRyHCMI2xDh 64FcCwnTugdn5CrPnlw0hjkECFxDRBhjmO/0GKYYv1K6FS45K5Lc+f2uuwgUZwWyKHLiQOvyurn7t 65Fs3xtXTnuBbl6ZiMu28OxCjUDBOMB0GA1UdDgQWBBR6nDgtPalG2JvSlWzdGRCi/Cu7NjAfBgNV 66HSMEGDAWgBR6nDgtPalG2JvSlWzdGRCi/Cu7NjAMBgNVHRMEBTADAQH/ 67-----END DATA----- 68 69$ openssl asn1parse -i < [SIGNATURE] 70 0:d=0 hl=2 l= 105 prim: BIT STRING 71-----BEGIN SIGNATURE----- 72A2kAMGYCMQCDwMSZVJZ8qThiNTV7VX57m8fdNnNS6cXIjRYoh4SozlYWmWGh87nhmJJCeD16jVM 73CMQDkroAY8oNi8RxLUor+LozhhVgu24tu6lcp4MP8H3Zy8bBea5HerAd1AqJp3Ox7KDU= 74-----END SIGNATURE----- 75