Description
Crypt::DSA versions before 1.22 for Perl draw the DSA signing nonce and private key from a biased random generator, leading to private-key recovery. "Crypt::DSA::Util::makerandom forces the high bit of every value it returns to obtain an exactly N-bit integer for prime search. The signing nonce and the private key are drawn from makerandom. Because the high bit is always set, the result is not uniform: its top bit is fixed, producing insecure values." An attacker who collects a modest number of signatures under an affected key, together with the public key, can recover the private key with a lattice attack. Keys used to sign with an affected version should be considered compromised and new keys should be generated.
Affected products
Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.
TIMLEGGE Crypt::DSA
Default version status: unaffected
0 to < 1.22affected
References
- https://metacpan.org/release/TIMLEGGE/Crypt-DSA-1.21/source/lib/Crypt/DSA/Util.pm#L56 ↗
- https://metacpan.org/release/TIMLEGGE/Crypt-DSA-1.22/diff/TIMLEGGE/Crypt-DSA-1.21#lib/Crypt/DSA/Util.pm ↗
- https://metacpan.org/release/TIMLEGGE/Crypt-DSA-1.22/changes ↗
- http://www.openwall.com/lists/oss-security/2026/07/05/1 ↗