mincrypt: support SHA-256 hash algorithm

- adds a library to compute the SHA-256 hash

- updates the RSA verifier to take an argument specifying either SHA-1
  or SHA-256

- updates DumpPublicKey to with new "key" version numbers for
  specifying SHA-256

- adds new argument to adb auth code to maintain existing behavior

Change-Id: I5b1406cf57c2b8993f6032eda3e29139f7740839
diff --git a/libmincrypt/Android.mk b/libmincrypt/Android.mk
index f58eab9..addbed8 100644
--- a/libmincrypt/Android.mk
+++ b/libmincrypt/Android.mk
@@ -4,13 +4,13 @@
 include $(CLEAR_VARS)
 
 LOCAL_MODULE := libmincrypt
-LOCAL_SRC_FILES := rsa.c rsa_e_3.c rsa_e_f4.c sha.c
+LOCAL_SRC_FILES := rsa.c rsa_e_3.c rsa_e_f4.c sha.c sha256.c
 include $(BUILD_STATIC_LIBRARY)
 
 include $(CLEAR_VARS)
 
 LOCAL_MODULE := libmincrypt
-LOCAL_SRC_FILES := rsa.c rsa_e_3.c rsa_e_f4.c sha.c
+LOCAL_SRC_FILES := rsa.c rsa_e_3.c rsa_e_f4.c sha.c sha256.c
 include $(BUILD_HOST_STATIC_LIBRARY)