OpenSSL and EC Libraries

OpenSSL Without Elliptic Curve Support

Some algorithms in OpenSSL library may be restricted by patent law. Due to strong coupling between the elliptic curve support Bitcoin requires and these nominally non-free algorithms, some Linux distributions (most notably Fedora) ship OpenSSL libraries with elliptic curve support disabled. Since Bitcoin depends on elliptic curve cryptography, it cannot be used with such libraries.

Fixes / Workarounds

Some fixes are

• Compile your own OpenSSL and use this rather than the distribution package manager's library.
• Use the RPMs provided by gmaxwell [1] rather than the distribution package manager's library. (Warning: as of May 2014, these libraries are still vulnerable to the Heartbleed exploit, which does not seriously affect Bitcoin but may expose other parts of your system.)