Add GoogleKeymaster. Very incomplete.

Change-Id: I53542c7132bd1a04afee93f3247b88ed7ed0bedc
diff --git a/ae.h b/ae.h
new file mode 100644
index 0000000..864d349
--- /dev/null
+++ b/ae.h
@@ -0,0 +1,164 @@
+/* ---------------------------------------------------------------------------
+ *
+ * AEAD API 0.12 - 23-MAY-2012
+ *
+ * This file gives an interface appropriate for many authenticated
+ * encryption with associated data (AEAD) implementations. It does not try
+ * to accommodate all possible options or limitations that an implementation
+ * might have -- you should consult the documentation of your chosen
+ * implementation to find things like RFC 5116 constants, alignment
+ * requirements, whether the incremental interface is supported, etc.
+ *
+ * This file is in the public domain. It is provided "as is", without
+ * warranty of any kind. Use at your own risk.
+ *
+ * Comments are welcome: Ted Krovetz <ted@krovetz>.
+ *
+ * ------------------------------------------------------------------------ */
+
+#ifndef _AE_H_
+#define _AE_H_
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/* --------------------------------------------------------------------------
+ *
+ * Constants
+ *
+ * ----------------------------------------------------------------------- */
+
+/* Return status codes: Negative return values indicate an error occurred.
+ * For full explanations of error values, consult the implementation's
+ * documentation.                                                          */
+#define AE_SUCCESS (0)        /* Indicates successful completion of call  */
+#define AE_INVALID (-1)       /* Indicates bad tag during decryption      */
+#define AE_NOT_SUPPORTED (-2) /* Indicates unsupported option requested   */
+
+/* Flags: When data can be processed "incrementally", these flags are used
+ * to indicate whether the submitted data is the last or not.               */
+#define AE_FINALIZE (1) /* This is the last of data                  */
+#define AE_PENDING (0)  /* More data of is coming                    */
+
+/* --------------------------------------------------------------------------
+ *
+ * AEAD opaque structure definition
+ *
+ * ----------------------------------------------------------------------- */
+
+typedef struct _ae_ctx ae_ctx;
+
+/* --------------------------------------------------------------------------
+ *
+ * Data Structure Routines
+ *
+ * ----------------------------------------------------------------------- */
+
+ae_ctx* ae_allocate(void* misc); /* Allocate ae_ctx, set optional ptr   */
+void ae_free(ae_ctx* ctx);       /* Deallocate ae_ctx struct            */
+int ae_clear(ae_ctx* ctx);       /* Undo initialization                 */
+int ae_ctx_sizeof(void);         /* Return sizeof(ae_ctx)               */
+/* ae_allocate() allocates an ae_ctx structure, but does not initialize it.
+ * ae_free() deallocates an ae_ctx structure, but does not zero it.
+ * ae_clear() zeroes sensitive values associated with an ae_ctx structure
+ * and deallocates any auxiliary structures allocated during ae_init().
+ * ae_ctx_sizeof() returns sizeof(ae_ctx), to aid in any static allocations.
+ */
+
+/* --------------------------------------------------------------------------
+ *
+ * AEAD Routines
+ *
+ * ----------------------------------------------------------------------- */
+
+int ae_init(ae_ctx* ctx, const void* key, int key_len, int nonce_len, int tag_len);
+/* --------------------------------------------------------------------------
+ *
+ * Initialize an ae_ctx context structure.
+ *
+ * Parameters:
+ *  ctx       - Pointer to an ae_ctx structure to be initialized
+ *  key       - Pointer to user-supplied key
+ *  key_len   - Length of key supplied, in bytes
+ *  nonce_len - Length of nonces to be used for this key, in bytes
+ *  tag_len   - Length of tags to be produced for this key, in bytes
+ *
+ * Returns:
+ *  AE_SUCCESS       - Success. Ctx ready for use.
+ *  AE_NOT_SUPPORTED - An unsupported length was supplied. Ctx is untouched.
+ *  Otherwise        - Error. Check implementation documentation for codes.
+ *
+ * ----------------------------------------------------------------------- */
+
+int ae_encrypt(ae_ctx* ctx, const void* nonce, const void* pt, int pt_len, const void* ad,
+               int ad_len, void* ct, void* tag, int final);
+/* --------------------------------------------------------------------------
+ *
+ * Encrypt plaintext; provide for authentication of ciphertext/associated data.
+ *
+ * Parameters:
+ *  ctx    - Pointer to an ae_ctx structure initialized by ae_init.
+ *  nonce  - Pointer to a nonce_len (defined in ae_init) byte nonce.
+ *  pt     - Pointer to plaintext bytes to be encrypted.
+ *  pt_len - number of bytes pointed to by pt.
+ *  ad     - Pointer to associated data.
+ *  ad_len - number of bytes pointed to by ad.
+ *  ct     - Pointer to buffer to receive ciphertext encryption.
+ *  tag    - Pointer to receive authentication tag; or NULL
+ *           if tag is to be bundled into the ciphertext.
+ *  final  - Non-zero if this call completes the plaintext being encrypted.
+ *
+ * If nonce!=NULL then a message is being initiated. If final!=0
+ * then a message is being finalized. If final==0 or nonce==NULL
+ * then the incremental interface is being used. If nonce!=NULL and
+ * ad_len<0, then use same ad as last message.
+ *
+ * Returns:
+ *  non-negative     - Number of bytes written to ct.
+ *  AE_NOT_SUPPORTED - Usage mode unsupported (eg, incremental and/or sticky).
+ *  Otherwise        - Error. Check implementation documentation for codes.
+ *
+ * ----------------------------------------------------------------------- */
+
+int ae_decrypt(ae_ctx* ctx, const void* nonce, const void* ct, int ct_len, const void* ad,
+               int ad_len, void* pt, const void* tag, int final);
+/* --------------------------------------------------------------------------
+ *
+ * Decrypt ciphertext; provide authenticity of plaintext and associated data.
+ *
+ * Parameters:
+ *  ctx    - Pointer to an ae_ctx structure initialized by ae_init.
+ *  nonce  - Pointer to a nonce_len (defined in ae_init) byte nonce.
+ *  ct     - Pointer to ciphertext bytes to be decrypted.
+ *  ct_len - number of bytes pointed to by ct.
+ *  ad     - Pointer to associated data.
+ *  ad_len - number of bytes pointed to by ad.
+ *  pt     - Pointer to buffer to receive plaintext decryption.
+ *  tag    - Pointer to tag_len (defined in ae_init) bytes; or NULL
+ *           if tag is bundled into the ciphertext. Non-NULL tag is only
+ *           read when final is non-zero.
+ *  final  - Non-zero if this call completes the ciphertext being decrypted.
+ *
+ * If nonce!=NULL then "ct" points to the start of a ciphertext. If final!=0
+ * then "in" points to the final piece of ciphertext. If final==0 or nonce==
+ * NULL then the incremental interface is being used. If nonce!=NULL and
+ * ad_len<0, then use same ad as last message.
+ *
+ * Returns:
+ *  non-negative     - Number of bytes written to pt.
+ *  AE_INVALID       - Authentication failure.
+ *  AE_NOT_SUPPORTED - Usage mode unsupported (eg, incremental and/or sticky).
+ *  Otherwise        - Error. Check implementation documentation for codes.
+ *
+ * NOTE !!! NOTE !!! -- The ciphertext should be assumed possibly inauthentic
+ *                      until it has been completely written and it is
+ *                      verified that this routine did not return AE_INVALID.
+ *
+ * ----------------------------------------------------------------------- */
+
+#ifdef __cplusplus
+} /* closing brace for extern "C" */
+#endif
+
+#endif /* _AE_H_ */