[OpenSSL-1.0.2] TNF local patch - CVE-2017-3737 Read/write after SSL object in error state

[Takehiko NOZAKI]

original commit message:

http://mail-index.netbsd.org/source-changes/2018/04/18/msg094491.html

[Takehiko NOZAKI]

fix in OpenSSL-1_0_2-stabled:

https://github.com/openssl/openssl/commit/898fb884b706aaeb283de4812340bb0bde8476dc

[Takehiko NOZAKI]

BUGFIX: Issue #173 - CVE-2017-3737 Read/write after SSL object in error state

cherry-picked from OpenSSL-1_0_2-stable branch: https://github.com/openssl/openssl/commit/898fb884b706aaeb283de4812340bb0bde8476dc

original commit message:

Don't allow read/write after fatal error

OpenSSL 1.0.2 (starting from version 1.0.2b) introduced an "error state" mechanism. The intent was that if a fatal error occurred during a handshake then OpenSSL would move into the error state and would immediately fail if you attempted to continue the handshake. This works as designed for the explicit handshake functions (SSL_do_handshake(), SSL_accept() and SSL_connect()), however due to a bug it does not work correctly if SSL_read() or SSL_write() is called directly. In that scenario, if the handshake fails then a fatal error will be returned in the initial function call. If SSL_read()/SSL_write() is subsequently called by the application for the same SSL object then it will succeed and the data is passed without being decrypted/encrypted directly from the SSL/TLS record layer.

In order to exploit this issue an attacker would have to trick an application into behaving incorrectly by issuing an SSL_read()/SSL_write() after having already received a fatal error.

Thanks to David Benjamin (Google) for reporting this issue and suggesting this fix.

CVE-2017-3737

Reviewed-by: Rich Salz [e-mail]

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