In Libgcrypt before 1.7.7, an attacker who learns the EdDSA...

Vulnerability Description

In Libgcrypt before 1.7.7, an attacker who learns the EdDSA session key (from side-channel observation during the signing process) can easily recover the long-term secret key. 1.7.7 makes a cipher/ecc-eddsa.c change to store this session key in secure memory, to ensure that constant-time point operations are used in the MPI library.

References

• http://www.oracle.com/technetwork/security-advisory/cpujul2018-4258247.html
• https://www.oracle.com/technetwork/security-advisory/cpujan2019-5072801.html
• https://git.gnupg.org/cgi-bin/gitweb.cgi?p=libgcrypt.git%3Ba=commit%3Bh=5a22de904a0a366ae79f03ff1e13a1232a89e26b
• http://www.debian.org/security/2017/dsa-3880
• http://www.securityfocus.com/bid/99046
• https://git.gnupg.org/cgi-bin/gitweb.cgi?p=libgcrypt.git%3Ba=commit%3Bh=f9494b3f258e01b6af8bd3941ce436bcc00afc56
• https://bugzilla.suse.com/show_bug.cgi?id=1042326