Revert "Add RSA encryption and decryption support."

This reverts commit 46a420de44adaadfbaf293ef4a01a70ed5855619.
diff --git a/rsa_operation.cpp b/rsa_operation.cpp
index df39006..a013b78 100644
--- a/rsa_operation.cpp
+++ b/rsa_operation.cpp
@@ -14,11 +14,8 @@
  * limitations under the License.
  */
 
-#include <limits.h>
-
-#include <openssl/err.h>
-#include <openssl/evp.h>
 #include <openssl/rsa.h>
+#include <openssl/evp.h>
 
 #include "rsa_operation.h"
 #include "openssl_utils.h"
@@ -40,8 +37,6 @@
         return KM_ERROR_UNIMPLEMENTED;
     case KM_PURPOSE_SIGN:
     case KM_PURPOSE_VERIFY:
-    case KM_PURPOSE_ENCRYPT:
-    case KM_PURPOSE_DECRYPT:
         return StoreData(input);
     }
 }
@@ -66,16 +61,13 @@
 
 keymaster_error_t RsaVerifyOperation::Finish(const Buffer& signature, Buffer* /* output */) {
 #if defined(OPENSSL_IS_BORINGSSL)
-    size_t message_size = data_.available_read();
+    if (data_.available_read() != RSA_size(rsa_key_))
+        return KM_ERROR_INVALID_INPUT_LENGTH;
 #else
-    if (data_.available_read() > INT_MAX)
+    if ((int)data_.available_read() != RSA_size(rsa_key_))
         return KM_ERROR_INVALID_INPUT_LENGTH;
-    int message_size = (int)data_.available_read();
 #endif
 
-    if (message_size != RSA_size(rsa_key_))
-        return KM_ERROR_INVALID_INPUT_LENGTH;
-
     if (data_.available_read() != signature.available_read())
         return KM_ERROR_VERIFICATION_FAILED;
 
@@ -91,81 +83,4 @@
     return KM_ERROR_VERIFICATION_FAILED;
 }
 
-const int OAEP_PADDING_OVERHEAD = 41;
-const int PKCS1_PADDING_OVERHEAD = 11;
-
-keymaster_error_t RsaEncryptOperation::Finish(const Buffer& /* signature */, Buffer* output) {
-    int openssl_padding;
-
-#if defined(OPENSSL_IS_BORINGSSL)
-    size_t message_size = data_.available_read();
-#else
-    if (data_.available_read() > INT_MAX)
-        return KM_ERROR_INVALID_INPUT_LENGTH;
-    int message_size = (int)data_.available_read();
-#endif
-
-    switch (padding_) {
-    case KM_PAD_RSA_OAEP:
-        openssl_padding = RSA_PKCS1_OAEP_PADDING;
-        if (message_size >= RSA_size(rsa_key_) - OAEP_PADDING_OVERHEAD) {
-            logger().error("Cannot encrypt %d bytes with %d-byte key and OAEP padding",
-                           data_.available_read(), RSA_size(rsa_key_));
-            return KM_ERROR_INVALID_INPUT_LENGTH;
-        }
-        break;
-    case KM_PAD_RSA_PKCS1_1_5_ENCRYPT:
-        openssl_padding = RSA_PKCS1_PADDING;
-        if (message_size >= RSA_size(rsa_key_) - PKCS1_PADDING_OVERHEAD) {
-            logger().error("Cannot encrypt %d bytes with %d-byte key and PKCS1 padding",
-                           data_.available_read(), RSA_size(rsa_key_));
-            return KM_ERROR_INVALID_INPUT_LENGTH;
-        }
-        break;
-    default:
-        logger().error("Padding mode %d not supported", padding_);
-        return KM_ERROR_UNSUPPORTED_PADDING_MODE;
-    }
-
-    output->Reinitialize(RSA_size(rsa_key_));
-    int bytes_encrypted = RSA_public_encrypt(data_.available_read(), data_.peek_read(),
-                                             output->peek_write(), rsa_key_, openssl_padding);
-
-    if (bytes_encrypted < 0) {
-        logger().error("Error %d encrypting data with RSA", ERR_get_error());
-        return KM_ERROR_UNKNOWN_ERROR;
-    }
-    assert(bytes_encrypted == RSA_size(rsa_key_));
-    output->advance_write(bytes_encrypted);
-
-    return KM_ERROR_OK;
-}
-
-keymaster_error_t RsaDecryptOperation::Finish(const Buffer& /* signature */, Buffer* output) {
-    int openssl_padding;
-    switch (padding_) {
-    case KM_PAD_RSA_OAEP:
-        openssl_padding = RSA_PKCS1_OAEP_PADDING;
-        break;
-    case KM_PAD_RSA_PKCS1_1_5_ENCRYPT:
-        openssl_padding = RSA_PKCS1_PADDING;
-        break;
-    default:
-        logger().error("Padding mode %d not supported", padding_);
-        return KM_ERROR_UNSUPPORTED_PADDING_MODE;
-    }
-
-    output->Reinitialize(RSA_size(rsa_key_));
-    int bytes_decrypted = RSA_private_decrypt(data_.available_read(), data_.peek_read(),
-                                              output->peek_write(), rsa_key_, openssl_padding);
-
-    if (bytes_decrypted < 0) {
-        logger().error("Error %d decrypting data with RSA", ERR_get_error());
-        return KM_ERROR_UNKNOWN_ERROR;
-    }
-    output->advance_write(bytes_decrypted);
-
-    return KM_ERROR_OK;
-}
-
 }  // namespace keymaster