HMAC_CTX_copy's documentation is off. It actually follows the old copy
functions which call FOO_init on dest first. Notably this means that they leak
memory if dest is currently in use.
Add HMAC_CTX_copy_ex as an analog of EVP_MD_CTX_copy and deprecate
HMAC_CTX_copy. (EVP_CIPHER_CTX_copy, in contrast, was correct from the start.)
Change-Id: I48566c858663d3f659bd356200cf862e196576c9
Reviewed-on: https://boringssl-review.googlesource.com/2694
Reviewed-by: Adam Langley <agl@google.com>
The expectation when calling HMAC with key=NULL and keylen=0 is to compute
HMAC on the provided data with a key of length 0 instead of using the
"previous" key, which in the case of HMAC() is whatever bytes happen to be
left on the stack when the HMAC_CTX struct is allocated.
Change-Id: I52a95e262ee4e15f1af3136cb9c07f42f40ce122
Reviewed-on: https://boringssl-review.googlesource.com/2660
Reviewed-by: Adam Langley <agl@google.com>
Initial fork from f2d678e6e89b6508147086610e985d4e8416e867 (1.0.2 beta).
(This change contains substantial changes from the original and
effectively starts a new history.)
