Rename module compat -> catlfish_compat.CATLFISH-69

Can't have two modules with the same name in a release.

1 files changed, 27 insertions, 0 deletions

diff --git a/src/catlfish_compat.erl b/src/catlfish_compat.erl
new file mode 100644
index 0000000..55c2b2e
--- /dev/null
+++ b/src/catlfish_compat.erl
@@ -0,0 +1,27 @@
+-module(catlfish_compat).
+-export([unpack_issuer/1, unpack_signature/1]).
+-include_lib("public_key/include/public_key.hrl").
+
+unpack_issuer(Issuer) ->
+    unpack_issuer(erlang:system_info(otp_release), Issuer).
+unpack_signature(Signature) ->
+    unpack_signature(erlang:system_info(otp_release), Signature).
+
+%% @doc Dig out alg, params and key from issuer.
+unpack_issuer("17", Issuer) ->
+    #'SubjectPublicKeyInfo'{
+       algorithm = #'AlgorithmIdentifier'{algorithm = Alg, parameters = Params},
+       subjectPublicKey = {0, Key}} = Issuer,
+    {Alg, Params, Key};
+unpack_issuer("18", Issuer) ->
+    #'SubjectPublicKeyInfo'{
+       algorithm = #'AlgorithmIdentifier'{algorithm = Alg, parameters = Params},
+       subjectPublicKey = Key} = Issuer,
+    {Alg, Params, Key}.
+
+%% @doc Unpack a #'Certificate'.signature, return the signature.
+unpack_signature("17", Signature) ->
+    {_, Sig} = Signature,
+    Sig;
+unpack_signature("18", Signature) ->
+    Signature.