* The **database model** would probably need to have a hashed password.

/// danger

Never store user's plaintext passwords. Always store a "secure hash" that you can then verify.

If you don't know, you will learn what a "password hash" is in the [security chapters](security/simple-oauth2.md#password-hashing).

///

## Multiple models { #multiple-models }

// md5sum
type SealMD5CurrFn func([]byte) []byte

// PutObjReader is a type that wraps sio.EncryptReader and
// underlying hash.Reader in a struct
type PutObjReader struct {
	*hash.Reader              // actual data stream
	rawReader    *hash.Reader // original data stream
	sealMD5Fn    SealMD5CurrFn
}

// Size returns the absolute number of bytes the Reader

        adjust = ~~adjust;
        // in GWT, we have to deal with integer overflow carefully
      }
      int hash = 1;
      for (Set<E> axis : axes) {
        hash = 31 * hash + (size() / axis.size() * axis.hashCode());

        hash = ~~hash;
      }
      hash += adjust;
      return ~~hash;
    }
  }

  /**
   * Returns the set of all possible subsets of {@code set}. For example, {@code

 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
 * implied.  See the License for the specific language governing
 * permissions and limitations under the License.
 */

package com.google.common.hash;

import com.google.common.annotations.GwtCompatible;
import com.google.errorprone.annotations.CanIgnoreReturnValue;

/** Static utility method for unchecked throwing of any {@link Throwable}. */
@GwtCompatible

 * or implied. See the License for the specific language governing permissions and limitations under
 * the License.
 */

package com.google.common.hash;

import com.google.common.annotations.Beta;
import com.google.errorprone.annotations.DoNotMock;
import java.io.Serializable;
import org.jspecify.annotations.Nullable;

/**

      return this.function.equals(that.function) && this.ordering.equals(that.ordering);
    }
    return false;
  }

  @Override
  public int hashCode() {
    return Objects.hash(function, ordering);
  }

  @Override
  public String toString() {
    return ordering + ".onResultOf(" + function + ")";
  }

  @GwtIncompatible @J2ktIncompatible private static final long serialVersionUID = 0;

  @Override
  protected boolean doEquivalent(F a, F b) {
    return resultEquivalence.equivalent(function.apply(a), function.apply(b));
  }

  @Override
  protected int doHash(F a) {
    return resultEquivalence.hash(function.apply(a));
  }

  @Override
  public boolean equals(@Nullable Object obj) {
    if (obj == this) {
      return true;
    }
    if (obj instanceof FunctionalEquivalence) {

    @DisplayName("Should return selected preauth hash")
    void testGetSelectedPreauthHash() throws Exception {
        // Given
        setPrivateField(response, "selectedPreauthHash", PreauthIntegrityNegotiateContext.HASH_ALGO_SHA512);

        // When
        int hash = response.getSelectedPreauthHash();

        // Then
        assertEquals(PreauthIntegrityNegotiateContext.HASH_ALGO_SHA512, hash);
    }

    @Test

		parts := make([]CompletePart, len(oi.Parts))
		for i, part := range oi.Parts {
			hr, err := hash.NewReader(ctx, io.LimitReader(gr, part.Size), part.Size, "", "", part.ActualSize)
			if err != nil {
				return fmt.Errorf("rebalanceObject: hash.NewReader() %w", err)
			}
			pi, err := z.PutObjectPart(ctx, bucket, oi.Name, res.UploadID,
				part.Number,
				NewPutObjReader(hr),

	if !etag.ContentMD5Requested(r.Header) && (crypto.S3KMS.IsRequested(r.Header) || crypto.SSEC.IsRequested(r.Header) || !globalServerCtxt.StrictS3Compat) {
		forceMD5 = mustGetUUIDBytes()
	}
	hashReader, err := hash.NewReaderWithOpts(ctx, reader, hash.Options{
		Size:       size,
		MD5Hex:     md5hex,
		SHA256Hex:  sha256hex,
		ActualSize: actualSize,
		DisableMD5: false,
		ForceMD5:   forceMD5,
	})
	if err != nil {