rpki-client remove hidden global

[Claudio Jeker]

I tripped over this and this optimisation hurts more then it helps.
So lets just create a new EVP_ENCODE_CTX for every base64_decode()
call and cleanup at the end of the call.

-- 
:wq Claudio

Index: encoding.c
===================================================================
RCS file: /cvs/src/usr.sbin/rpki-client/encoding.c,v
retrieving revision 1.10
diff -u -p -r1.10 encoding.c
--- encoding.c  24 Nov 2021 15:24:16 -0000      1.10
+++ encoding.c  19 Apr 2022 17:16:32 -0000
@@ -96,21 +96,21 @@ int
 base64_decode(const unsigned char *in, size_t inlen,
     unsigned char **out, size_t *outlen)
 {
-       static EVP_ENCODE_CTX *ctx;
-       unsigned char *to;
+       EVP_ENCODE_CTX *ctx;
+       unsigned char *to = NULL;
        size_t tolen;
        int evplen;
 
-       if (ctx == NULL && (ctx = EVP_ENCODE_CTX_new()) == NULL)
+       if ((ctx = EVP_ENCODE_CTX_new()) == NULL)
                err(1, "EVP_ENCODE_CTX_new");
 
        *out = NULL;
        *outlen = 0;
 
        if (base64_decode_len(inlen, &tolen) == -1)
-               return -1;
+               goto fail;
        if ((to = malloc(tolen)) == NULL)
-               return -1;
+               goto fail;
 
        evplen = tolen;
        EVP_DecodeInit(ctx);
@@ -121,10 +121,13 @@ base64_decode(const unsigned char *in, s
                goto fail;
        *outlen += evplen;
        *out = to;
+
+       EVP_ENCODE_CTX_free(ctx);
        return 0;
 
 fail:
        free(to);
+       EVP_ENCODE_CTX_free(ctx);
        return -1;
 }