DSA Private Key and Public Key Pair Sample

JDK Tutorials - Herong's Tutorial Examples

∟Private key and Public Key Pair Generation

∟DSA Private Key and Public Key Pair Sample

This section provides a tutorial example on how to run JcaKeyPair.java to generate a DSA private key and public key pair sample. Keys are stored PKCS#8 and X.509 encoding formats.

Here is the result of my first test of JcaKeyPair.java - generating a pair of DSA private key and public key.

herong> javac JcaKeyPair.java

herong> java JcaKeyPair 512 dsa dsa
KeyPairGenerator Object Info:
Algorithm = DSA
Provider = SUN version 10
Key Size = 512
toString = sun.security.provider.DSAKeyPairGenerator$Current@6a5fc7f7

Private Key Info:
Algorithm = DSA
Saved File = dsa.pri
Size = 202
Format = PKCS#8
toString = sun.security.provider.DSAPrivateKey@23d27

Public Key Info:
Algorithm = DSA
Saved File = dsa.pub
Size = 243
Format = X.509
toString = Sun DSA Public Key
Parameters:
p:
fca682ce 8e12caba 26efccf7 110e526d b078b05e decbcd1e b4a208f3 ae1617ae
01f35b91 a47e6df6 3413c5e1 2ed0899b cd132acd 50d99151 bdc43ee7 37592e17
q:
962eddcc 369cba8e bb260ee6 b6a126d9 346e38c5
g:
678471b2 7a9cf44e e91a49c5 147db1a9 aaf244f0 5a434d64 86931d2d 14271b9e
35030b71 fd73da17 9069b32e 2935630e 1c206235 4d0da20a 6c416e50 be794ca4

y:
b5c76bec 0ef39fe3 8b70172f 2d019656 bbc685c6 719813a8 1c55ab60 a6d7cd8f
fee96d24 5253b4c7 2e56b5e9 6ab9a2f2 8c440f10 4e053e14 c6b9a693 72942472

The program seems to be working:

Since I am not specifying the provider name, the implementation of the DSA algorithm provided in the default security package was selected. Of course, Sun is the provider of the default security package.
The key pair generated from the generateKeyPair() method indeed has two keys, a private key and a public key.
The private key was written to a file using PKCS#8 format, and the public key was written to another file using X.509 format.

In order to see the keys, I need to use my other program, HexWriter.java, to convert binary data to hex numbers. See chapter "Encoding Conversion" for details.

Here is how to look at DSA key files in hex numbers, 16 bytes per line:

herong> javac HexWriter.java

herong> java HexWriter dsa.pri dsa_pri.hex

herong> more dsa_pri.hex
3081C60201003081A806072A8648CE38
040130819C024100FCA682CE8E12CABA
26EFCCF7110E526DB078B05EDECBCD1E
B4A208F3AE1617AE01F35B91A47E6DF6
3413C5E12ED0899BCD132ACD50D99151
BDC43EE737592E17021500962EDDCC36
9CBA8EBB260EE6B6A126D9346E38C502
40678471B27A9CF44EE91A49C5147DB1
A9AAF244F05A434D6486931D2D14271B
9E35030B71FD73DA179069B32E293563
0E1C2062354D0DA20A6C416E50BE794C
A4041602143FFB34A2B13206A69B3CE9
4C1B8AF6D4A259DE00

herong> java -cp . HexWriter dsa.pub dsa_pub.hex

herong> more dsa_pub.hex
3081F13081A806072A8648CE38040130
819C024100FCA682CE8E12CABA26EFCC
F7110E526DB078B05EDECBCD1EB4A208
F3AE1617AE01F35B91A47E6DF63413C5
E12ED0899BCD132ACD50D99151BDC43E
E737592E17021500962EDDCC369CBA8E
BB260EE6B6A126D9346E38C502406784
71B27A9CF44EE91A49C5147DB1A9AAF2
44F05A434D6486931D2D14271B9E3503
0B71FD73DA179069B32E2935630E1C20
62354D0DA20A6C416E50BE794CA40344
00024100B5C76BEC0EF39FE38B70172F
2D019656BBC685C6719813A81C55AB60
A6D7CD8FFEE96D245253B4C72E56B5E9
6AB9A2F28C440F104E053E14C6B9A693
72942472