Summary

Define the default signature algorithm of an RSASSA-PSS key for keytool and jarsigner.

Problem

Both keytool and jarsigner support default signature algorithms when no -sigalg is specified. For example, SHA256withRSA for an RSA key. We need to define one for an RSASSA-PSS key.

Currently, an error occurs if it's not provided:

$ keytool -genkeypair -keyalg rsassa-pss -storepass changeit -dname CN=A
keytool error: java.lang.IllegalArgumentException: Cannot derive signature algorithm from RSASSA-PSS

Solution

The default signature algorithm for an RSASSA-PSS key is RSASSA-PSS.

Specification

diff --git a/closed/src/java.base/share/man/keytool.md b/closed/src/java.base/share/man/keytool.md
--- a/closed/src/java.base/share/man/keytool.md
+++ b/closed/src/java.base/share/man/keytool.md
@@ -1241,16 +1241,17 @@
 algorithm (`-sigalg` option) is derived from the algorithm of the underlying
 private key to provide an appropriate level of security strength as follows:

-keyalg   keysize   default sigalg
--------  --------  --------------
-DSA      any size  SHA256withDSA
-RSA      \<= 3072  SHA256withRSA
-         \<= 7680  SHA384withRSA
-         \> 7680   SHA512withRSA
-EC       \< 384    SHA256withECDSA
-         \< 512    SHA384withECDSA
-         = 512     SHA512withECDSA
--------  --------  --------------
+keyalg      keysize   default sigalg
+----------  --------  --------------
+DSA         any size  SHA256withDSA
+RSA         \<= 3072  SHA256withRSA
+            \<= 7680  SHA384withRSA
+            \> 7680   SHA512withRSA
+EC          \< 384    SHA256withECDSA
+            \< 512    SHA384withECDSA
+            = 512     SHA512withECDSA
+RSASSA-PSS  any size  RSASSA-PSS
+----------  --------  --------------

 **Note:**

diff --git a/closed/src/jdk.jartool/share/man/jarsigner.md b/closed/src/jdk.jartool/share/man/jarsigner.md
--- a/closed/src/jdk.jartool/share/man/jarsigner.md
+++ b/closed/src/jdk.jartool/share/man/jarsigner.md
@@ -226,16 +226,17 @@
 By default, the `jarsigner` command signs a JAR file using one of the following
 algorithms files depending on the type and size of the private key:

-keyalg   keysize   default sigalg
--------  --------  --------------
-DSA      any size  SHA256withDSA
-RSA      \<= 3072  SHA256withRSA
-         \<= 7680  SHA384withRSA
-         \> 7680   SHA512withRSA
-EC       \< 384    SHA256withECDSA
-         \< 512    SHA384withECDSA
-         = 512     SHA512withECDSA
--------  --------  --------------
+keyalg      keysize   default sigalg
+----------  --------  --------------
+DSA         any size  SHA256withDSA
+RSA         \<= 3072  SHA256withRSA
+            \<= 7680  SHA384withRSA
+            \> 7680   SHA512withRSA
+EC          \< 384    SHA256withECDSA
+            \< 512    SHA384withECDSA
+            = 512     SHA512withECDSA
+RSASSA-PSS  any size  RSASSA-PSS
+----------  --------  --------------

 These default signature algorithms can be overridden by using the `-sigalg`
 option.