The ITU standard X.509 is a wide spread format for certificates. When displayed as text, this type of certificate looks like the following:
Certificate: Data: Version: 3 (0x2) Serial Number: 1 (0x1) Signature Algorithm: md5WithRSAEncryption Issuer: CN=CA/Email=ca@trustme.dom, OU=Certificate Authority, O=TrustMe Ltd, ST=Austria, L=Graz, C=XY, Validity Not Before: Oct 29 17:39:10 2000 GMT Not After : Oct 29 17:39:10 2001 GMT Subject: CN=anywhere.com/Email=xyz@anywhere.com, OU=Web Lab, O=Home, L=Vienna, ST=Austria, C=DE Subject Public Key Info: Public Key Algorithm: rsaEncryption RSA Public Key: (1024 bit) Modulus (1024 bit): 00:c4:40:4c:6e:14:1b:61:36:84:24:b2:61:c0:b5: d7:e4:7a:a5:4b:94:ef:d9:5e:43:7f:c1:64:80:fd: 9f:50:41:6b:70:73:80:48:90:f3:58:bf:f0:4c:b9: 90:32:81:59:18:16:3f:19:f4:5f:11:68:36:85:f6: 1c:a9:af:fa:a9:a8:7b:44:85:79:b5:f1:20:d3:25: 7d:1c:de:68:15:0c:b6:bc:59:46:0a:d8:99:4e:07: 50:0a:5d:83:61:d4:db:c9:7d:c3:2e:eb:0a:8f:62: 8f:7e:00:e1:37:67:3f:36:d5:04:38:44:44:77:e9: f0:b4:95:f5:f9:34:9f:f8:43 Exponent: 65537 (0x10001) X509v3 extensions: X509v3 Subject Alternative Name: email:xyz@anywhere.com Netscape Comment: mod_ssl generated test server certificate Netscape Cert Type: SSL Server Signature Algorithm: md5WithRSAEncryption 12:ed:f7:b3:5e:a0:93:3f:a0:1d:60:cb:47:19:7d:15:59:9b: 3b:2c:a8:a3:6a:03:43:d0:85:d3:86:86:2f:e3:aa:79:39:e7: 82:20:ed:f4:11:85:a3:41:5e:5c:8d:36:a2:71:b6:6a:08:f9: cc:1e:da:c4:78:05:75:8f:9b:10:f0:15:f0:9e:67:a0:4e:a1: 4d:3f:16:4c:9b:19:56:6a:f2:af:89:54:52:4a:06:34:42:0d: d5:40:25:6b:b0:c0:a2:03:18:cd:d1:07:20:b6:e5:c5:1e:21: 44:e7:c5:09:d2:d5:94:9d:6c:13:07:2f:3b:7c:4c:64:90:bf: ff:8e