ChaCha20 code uses its own custom cipher_data. Add EVP_CIPH_CUSTOM_IV
and EVP_CIPH_ALWAYS_CALL_INIT so that the key and the iv can be set by
different calls of EVP_CipherInit_ex().
Reviewed-by: NRich Salz <rsalz@openssl.org>
Reviewed-by: NRichard Levitte <levitte@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/2156)

The offset to the memory to clear was incorrect, causing a heap buffer
overflow.

CVE-2016-7054

Thanks to Robert Święcki for reporting this
Reviewed-by: NRich Salz <rsalz@openssl.org>

 extra spacing and 80 cols
Reviewed-by: NRich Salz <rsalz@openssl.org>
Reviewed-by: NRichard Levitte <levitte@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/1366)

chacha20_poly1305_init_key() dereferences NULL when called with inkey !=
NULL && iv == NULL. This function is called by EVP_EncryptInit_ex()
family, whose documentation allows setting key and iv in separate calls.
Reviewed-by: NMatt Caswell <matt@openssl.org>
Reviewed-by: NRichard Levitte <levitte@openssl.org>

Reviewed-by: NRichard Levitte <levitte@openssl.org>

Rename BUF_{strdup,strlcat,strlcpy,memdup,strndup,strnlen}
to OPENSSL_{strdup,strlcat,strlcpy,memdup,strndup,strnlen}
Add #define's for the old names.
Add CRYPTO_{memdup,strndup}, called by OPENSSL_{memdup,strndup} macros.
Reviewed-by: NTim Hudson <tjh@openssl.org>

Thanks to: David Benjamin of Chromuim.
Reviewed-by: NRich Salz <rsalz@openssl.org>

Reviewed-by: NRichard Levitte <levitte@openssl.org>