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wolfSSL / wolfssl

The wolfSSL library is a small, fast, portable implementation of TLS/SSL for embedded devices to the cloud. wolfSSL supports up to TLS 1.3 and DTLS 1.3!
https://www.wolfssl.com
GNU General Public License v2.0
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EVP_CipherUpdate can read memory out-of-bounds #2264

Closed vaintroub closed 5 years ago

vaintroub commented 5 years ago

This line https://github.com/wolfSSL/wolfssl/blob/10dde24363810b97ef83492f9c550dfc2a827995/wolfcrypt/src/evp.c#L361

can access up to 16 bytes of memory out-of-bounds. The out buffer in this case (decryption, no-padding) can/should be as big as input, but in some circumstances the function will try to copy 16 bytes beyond the end of it.

It is also good question why EVP_CipherUpdate would try to save the "last block" , since this lastBlock seems to be of no use EVP_CipherFinal in special case of no-padding.

vaintroub commented 5 years ago

MariaDB ran into this bug here https://jira.mariadb.org/browse/MDEV-19581 , and here https://jira.mariadb.org/browse/MDEV-19582 . In both cases, input and output have the same size, and no-padding mode is used for decryption

kaleb-himes commented 5 years ago

Under Review.

kaleb-himes commented 5 years ago

Test case added to detect moving forward and fix supplied in #2272

Thank you so much for the report @vaintroub, let us know if you find anything else. For valid bug reports our HR department is more than happy to put together a gift basket for your trouble, if you want to receive some "swag" (mugs, stickers, other logo items that are import friendly even overseas) please shoot me an email directly at kaleb@wolfssl.com with a physical mailing address and I will be happy to have our HR department send you a gift basket for your efforts!

Warm Regards,

K

kaleb-himes commented 5 years ago

Solution has been merged. Please let us know if you have any other issues.

Warm Regards,

K