Decouple PKCS#12 hash lookup from the OID table.

This isn't strictly necessary for Chromium yet, but we already have a
decoupled version of hash algorithm parsing available. For now, don't
export it but eventually we may wish to use it for OCSP.

BUG=54

Change-Id: If460d38d48bd47a2b4a853779f210c0cf7ee236b
Reviewed-on: https://boringssl-review.googlesource.com/14211
Reviewed-by: Steven Valdez <svaldez@chromium.org>
Reviewed-by: David Benjamin <davidben@google.com>
Commit-Queue: Steven Valdez <svaldez@chromium.org>
Commit-Queue: David Benjamin <davidben@google.com>
CQ-Verified: CQ bot account: commit-bot@chromium.org <commit-bot@chromium.org>
diff --git a/include/openssl/digest.h b/include/openssl/digest.h
index 87de3df..2de84f7 100644
--- a/include/openssl/digest.h
+++ b/include/openssl/digest.h
@@ -283,5 +283,7 @@
 #endif
 
 #define DIGEST_R_INPUT_NOT_INITIALIZED 100
+#define DIGEST_R_DECODE_ERROR 101
+#define DIGEST_R_UNKNOWN_HASH 102
 
 #endif  /* OPENSSL_HEADER_DIGEST_H */