L'outil "openssl x509" donne une belle, concise, représentation texte lisible par l'homme d'un certificat X.509 en utilisant l'option "-text":
openssl x509 -noout -text -in CA_2048bit.pem
La sortie ressemble à ceci:
Certificate:
Data:
Version: 3 (0x2)
Serial Number:
00:11:22:33:44:55:66:77:88:99
Signature Algorithm: sha1WithRSAEncryption
Issuer: CN=Some CA, OU=Dept, O=MyOrganization, ST=Mazowieckie, C=PL
Validity
Not Before: Jun 17 14:24:59 2009 GMT
Not After : Jun 17 14:24:57 2029 GMT
Subject: CN=Some Party, OU=Dept, O=MyOrganization, ST=Mazowieckie, C=PL
Subject Public Key Info:
Public Key Algorithm: rsaEncryption
RSA Public Key: (2048 bit)
Modulus (2048 bit):
00:11:22:33:44:55:66:77:88:99:aa:bb:cc:dd:ee:
00:11:22:33:44:55:66:77:88:99:aa:bb:cc:dd:ee:
00:11:22:33:44:55:66:77:88:99:aa:bb:cc:dd:ee:
00:11:22:33:44:55:66:77:88:99:aa:bb:cc:dd:ee:
00:11:22:33:44:55:66:77:88:99:aa:bb:cc:dd:ee:
00:11:22:33:44:55:66:77:88:99:aa:bb:cc:dd:ee:
00:11:22:33:44:55:66:77:88:99:aa:bb:cc:dd:ee:
00:11:22:33:44:55:66:77:88:99:aa:bb:cc:dd:ee:
00:11:22:33:44:55:66:77:88:99:aa:bb:cc:dd:ee:
00:11:22:33:44:55:66:77:88:99:aa:bb:cc:dd:ee:
00:11:22:33:44:55:66:77:88:99:aa:bb:cc:dd:ee:
00:11:22:33:44:55:66:77:88:99:aa:bb:cc:dd:ee:
00:11:22:33:44:55:66:77:88:99:aa:bb:cc:dd:ee:
00:11:22:33:44:55:66:77:88:99:aa:bb:cc:dd:ee:
00:11:22:33:44:55:66:77:88:99:aa:bb:cc:dd:ee:
00:11:22:33:44:55:66:77:88:99:aa:bb:cc:dd:ee:
00:11:22:33:44:55:66:77:88:99:aa:bb:cc:dd:ee:
00:11
Exponent: 65537 (0x10001)
X509v3 extensions:
X509v3 Basic Constraints: critical
CA:TRUE, pathlen:0
Signature Algorithm: sha1WithRSAEncryption
00:11:22:33:44:55:66:77:88:99:aa:bb:cc:dd:ee:ff:00:11:
00:11:22:33:44:55:66:77:88:99:aa:bb:cc:dd:ee:ff:00:11:
00:11:22:33:44:55:66:77:88:99:aa:bb:cc:dd:ee:ff:00:11:
00:11:22:33:44:55:66:77:88:99:aa:bb:cc:dd:ee:ff:00:11:
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00:11:22:33:44:55:66:77:88:99:aa:bb:cc:dd:ee:ff:00:11:
00:11:22:33
Ceci est bien sûr un peu long en raison de la signature et des informations de module.
Malheureusement, toutes ces données sont nécessaires pour vérifier l'authenticité du certificat et pour l'utiliser pour vérifier les signatures numériques authentifiées avec, respectivement.
Sans cela, le reste du contenu du certificat ne prouve rien.
Avez-vous regardé les codes QR? ils peuvent contenir jusqu'à 4 296 chars. –