This section provides test result of JcaSignatureTest.java with SHA1withDSA and SHA1withRSA digital signature algorithms.
Here is the result of my first test of JcaSignatureTest.java with the SHA1withDSA algorithm.
It is done with JDK 1.3.1.
javac -classpath . JcaSignatureTest.java
java -cp . JcaSignatureTest JcaSignatureTest.class
sign.dsa DSA SHA1withDSA
Signature Object Info:
Algorithm = SHA1withDSA
Provider = SUN version 1.2
Sign Processing Info:
Number of input bytes = 3154
Number of output bytes = 46
Signature Object Info:
Algorithm = SHA1withDSA
Provider = SUN version 1.2
Verify Processing Info:
Number of input bytes = 3154
Verification result = true
java HexWriter sign.dsa sign_dsa.hex
Number of input bytes: 46
type sign_dsa.hex
302C0214008C8936A9A4C5B68D297C23
F867351E036231C00214199BF3F4FF82
C4C4AC4A086F2013290A8FAEFC05
The program seems to be working:
A pair of keys is generated using the DSA algorithm first.
Then a signature is generated for input file, JcaSignatureTest.class, using
the SHA1withDSA algorithm, which uses SHA-1 for the message digest generation, and
DSA for encryption.
Finally, the signature is verified with the public key and the result shows
that the signature is valid.
Of course, you can choose other combinations of different key pair generation algorithms
and message digest algorithms. For example, SHA1withRSA:
java -cp . JcaSignatureTest JcaSignatureTest.class
sign.rsa RSA SHA1withRSA
Signature Object Info:
Algorithm = SHA1withRSA
Provider = SunRsaSign version 1.0
Sign Processing Info:
Number of input bytes = 3154
Number of output bytes = 64
Signature Object Info:
Algorithm = SHA1withRSA
Provider = SunRsaSign version 1.0
Verify Processing Info:
Number of input bytes = 3154
Verification result = true
java -cp . JcaSignatureTest JcaSignatureTest.class
sign_2.rsa RSA MD5withRSA
Signature Object Info:
Algorithm = MD5withRSA
Provider = SunRsaSign version 1.0
Sign Processing Info:
Number of input bytes = 3154
Number of output bytes = 64
Signature Object Info:
Algorithm = MD5withRSA
Provider = SunRsaSign version 1.0
Verify Processing Info:
Number of input bytes = 3154
Verification result = true
java -cp . JcaSignatureTest JcaSignatureTest.class
sign_3.rsa RSA MD2withRSA
Signature Object Info:
Algorithm = MD2withRSA
Provider = SunRsaSign version 1.0
Sign Processing Info:
Number of input bytes = 3154
Number of output bytes = 64
Signature Object Info:
Algorithm = MD2withRSA
Provider = SunRsaSign version 1.0
Verify Processing Info:
Number of input bytes = 3154
Verification result = true
This sample program generates the signature and verifies the signature
in single program. But in the real world, we must have at least two programs, one to
be used by the sender of the date to generate the signature, and the other to be used
by the receiver to verify the signature.
