Modify providers that keep track of underlying algorithms

With some provider implementations, there are underlying ciphers,
digests and macs.  For some of them, the name was retrieved from the
method, but since the methods do not store those any more, we add
different mechanics.

For code that needs to pass on the name of a cipher or diges via
parameters, we simply locally store the name that was used when
fetching said cipher or digest.  This will ensure that any underlying
code that needs to fetch that same cipher or digest does so with the
exact same name instead of any random name from the set of names
associated with the algorithm.

For code that needs to check what kind of algorithm was passed, we
provide EVP_{type}_is_a(), that returns true if the given method has
the given name as one of its names.

Reviewed-by: Matt Caswell <matt@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/9897)

1 files changed, 5 insertions, 0 deletions

diff --git a/crypto/evp/mac_meth.c b/crypto/evp/mac_meth.c
index 3dc58c1..8c47a6c 100644
--- a/crypto/evp/mac_meth.c
+++ b/crypto/evp/mac_meth.c
@@ -168,6 +168,11 @@ void EVP_MAC_free(EVP_MAC *mac)
     evp_mac_free(mac);
 }
 
+int EVP_MAC_is_a(const EVP_MAC *mac, const char *name)
+{
+    return evp_is_a(mac->prov, mac->name_id, name);
+}
+
 const char *EVP_MAC_name(const EVP_MAC *mac)
 {
     return evp_first_name(mac->prov, mac->name_id);