Hi, below one tip for IllegalArgumentException:

the command (keytool -list -v -keystore) for show some information about your keystore throws this exception below:

keytool -list -v -keystore certificado.javaks
Insira a senha do armazenamento de chaves:

Tipo de armazenamento de chaves: JKS
Fornecedor de armazenamento de chaves: SUN

erro de keytool: java.lang.IllegalArgumentException: unknown format type at
java.lang.IllegalArgumentException: unknown format type at

try change the jdk version, appears to be some incompatibility. Works for me.

jdk version that threw the exception:
java version "1.6.0_26"
Java(TM) SE Runtime Environment (build 1.6.0_26-b03)
Java HotSpot(TM) 64-Bit Server VM (build 20.1-b02, mixed mode)

works jdk version:
java version "1.5.0_22"
Java(TM) 2 Runtime Environment, Standard Edition (build 1.5.0_22-b03)
Java HotSpot(TM) 64-Bit Server VM (build 1.5.0_22-b03, mixed mode)

My OS is Ubuntu 10.10

thread:
http://www.guj.com.br/java/126669-erro-importa-certificado-digitado