On Sun Jun 29 10:51:32 2014, [email protected] wrote:
>
> Well, I believe that security implications due to key/IV reuse happen
> with all ciphers not just AES in gcm mode, right? There must have
> been some very good reasons to introduce EVP_CIPHER_CTX_copy in the
> first place.
>

The implications vary from one cipher mode to another. AES GCM uses counter
mode and repeated IVs have rather severe consquences. See for example SP800-38D
Appendix A.

> Concerning my own use case, I was using EVP_CIPHER_CTX handle as a
> "cipher template" - i.e. select a cipher and set a key; foreach
> data block clone the context, set IV and decrypt.
>

Ah now that is a legitimate use case as long as you make sure the IVs are
unique. I'll apply your fix.

Steve.
--
Dr Stephen N. Henson. OpenSSL project core developer.
Commercial tech support now available see: http://www.openssl.org

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