This section show the difference between following private key formats with samples:
- PKCS#5 plain private key
- PKCS#8 plain private key
- PKCS#5 encrypted private key
- PKCS#8 encrypted private key
PKCS#5 plain private key
-----BEGIN RSA PRIVATE KEY-----
MIIBOwIBAAJBANxtmQ1Kccdp7HBNt8zgTai48Vv617bj4SnhkcMN99sCQ2Naj/sp
... (snip) ...
NiCYNLiCawBbpZnYw/ztPVACK4EwOpUy+u19cMB0JA==
-----END RSA PRIVATE KEY-----
PKCS#8 plain private key
-----BEGIN PRIVATE KEY-----
MIIBVAIBADANBgkqhkiG9w0BAQEFAASCAT4wggE6AgEAAkEA6GZN0rQFKRIVaPOz
... (snip) ...
LaLGdd9G63kLg85eldSy55uIAXsvqQIgfSYaliVtSbAgyx1Yfs3hJ+CTpNKzTNv/
Fx80EltYV6k=
-----END PRIVATE KEY-----
PKCS#5 encrypted private key
-----BEGIN RSA PRIVATE KEY-----
Proc-Type: 4,ENCRYPTED
DEK-Info: DES-EDE3-CBC,E83B4019057F55E9
iIPs59nQn4RSd7ppch9/vNE7PfRSHLoQFmaAjaF0DxjV9oucznUjJq2gphAB2E2H
... (snip) ...
y5IT1MZPgN3LNkVSsLPWKo08uFZQdfu0JTKcn7NPyRc=
-----END RSA PRIVATE KEY-----
PKCS#8 encrypted private key
-----BEGIN ENCRYPTED PRIVATE KEY-----
MIIBpjBABgkqhkiG9w0BBQ0wMzAbBgkqhkiG9w0BBQwwDgQIU9Y9p2EfWucCAggA
... (snip) ...
IjsZNp6zmlqf/RXnETsJjGd0TXRWaEdu+XOOyVyPskX2177X9DUJoD31
-----END ENCRYPTED PRIVATE KEY-----
To convert from PKCS#5 private key to encrypted PKCS#8 private key:
% openssl pkcs8 -in p5plain.pem -topk8 -v2 des3 -out p8enc.pem -passout pass:passwd