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Diffstat (limited to 'keystore/java/android/security')
| -rw-r--r-- | keystore/java/android/security/EcIesParameterSpec.java | 272 |
1 files changed, 0 insertions, 272 deletions
diff --git a/keystore/java/android/security/EcIesParameterSpec.java b/keystore/java/android/security/EcIesParameterSpec.java deleted file mode 100644 index 1cd8784..0000000 --- a/keystore/java/android/security/EcIesParameterSpec.java +++ /dev/null @@ -1,272 +0,0 @@ -package android.security; - -import android.annotation.IntDef; -import android.annotation.NonNull; -import android.annotation.Nullable; - -import java.lang.annotation.Retention; -import java.lang.annotation.RetentionPolicy; -import java.security.spec.AlgorithmParameterSpec; - -import javax.crypto.Cipher; -import javax.crypto.Mac; - -/** - * {@link AlgorithmParameterSpec} for ECIES (Integrated Encryption Scheme using Elliptic Curve - * cryptography) based on {@code ISO/IEC 18033-2}. - * - * <p>ECIES is a hybrid authenticated encryption scheme. Encryption is performed using an Elliptic - * Curve (EC) public key. The resulting ciphertext can be decrypted only using the corresponding EC - * private key. The scheme is called hybrid because the EC key is only used to securely encapsulate - * symmetric key material. Encryption of plaintext and authentication of the corresponding - * ciphertext is performed using symmetric cryptography. - * - * <p>Encryption using ECIES consists of two stages: - * <ol> - * <li>Key Encapsulation Mechanism (KEM) randomly generates symmetric key material and securely - * encapsulates it in the output so that it can be extracted by the KEM when decrypting. - * Encapsulated key material is represented in the output as an EC point.</li> - * <li>The above symmetric key material is used by Data Encapsulation Mechanism (DEM) to encrypt the - * provided plaintext and authenticate the ciphertext. The resulting authenticated ciphertext is - * then output. When decrypting, the DEM first authenticates the ciphertext and, only if it - * authenticates, decrypts the ciphertext and outputs the plaintext.</li> - * </ol> - * - * <p>Details of KEM: - * <ul> - * <li>Only curves with cofactor of {@code 1} are supported.</li> - * <li>{@code CheckMode}, {@code OldCofactorMode}, {@code CofactorMode}, and {@code SingleHashMode} - * are {@code 0}. - * <li>Point format is specified by {@link #getKemPointFormat()}.</li> - * <li>KDF algorithm is specified by {@link #getKemKdfAlgorithm()}.</li> - * </ul> - * - * <p>Details of DEM: - * <ul> - * <li>Only DEM1-like mechanism is supported, with its symmetric cipher (SC) specified by - * {@link #getDemCipherTransformation()} (e.g., {@code AES/CBC/NoPadding} for standard DEM1) and - * MAC algorithm specified by {@link #getDemMacAlgorithm()} (e.g., {@code HmacSHA1} for standard - * DEM1).</li> - * </ul> - */ -public class EcIesParameterSpec implements AlgorithmParameterSpec { - - /** - * @hide - */ - @Retention(RetentionPolicy.SOURCE) - @IntDef({ - POINT_FORMAT_UNSPECIFIED, - POINT_FORMAT_UNCOMPRESSED, - POINT_FORMAT_COMPRESSED, - }) - public @interface PointFormatEnum {} - - /** Unspecified EC point format. */ - public static final int POINT_FORMAT_UNSPECIFIED = -1; - - /** - * Uncompressed EC point format: both coordinates are stored separately. - * - * <p>The wire format is byte {@code 0x04} followed by binary representation of the {@code x} - * coordinate followed by binary representation of the {@code y} coordinate. See - * {@code ISO 18033-2} section {@code 5.4.3}. - */ - public static final int POINT_FORMAT_UNCOMPRESSED = 0; - - /** - * Compressed EC point format: only one coordinate is stored. - * - * <p>The wire format is byte {@code 0x02} or {@code 0x03} (depending on the value of the stored - * coordinate) followed by the binary representation of the {@code x} coordinate. See - * {@code ISO 18033-2} section {@code 5.4.3}. - */ - public static final int POINT_FORMAT_COMPRESSED = 1; - - /** - * Default parameter spec: compressed point format, {@code HKDFwithSHA256}, DEM uses 128-bit AES - * GCM. - */ - public static final EcIesParameterSpec DEFAULT = new EcIesParameterSpec( - POINT_FORMAT_COMPRESSED, - "HKDFwithSHA256", - "AES/GCM/NoPadding", - 128, - null, - 0); - - private final @PointFormatEnum int mKemPointFormat; - private final String mKemKdfAlgorithm; - private final String mDemCipherTransformation; - private final int mDemCipherKeySize; - private final String mDemMacAlgorithm; - private final int mDemMacKeySize; - - private EcIesParameterSpec( - @PointFormatEnum int kemPointFormat, - String kemKdfAlgorithm, - String demCipherTransformation, - int demCipherKeySize, - String demMacAlgorithm, - int demMacKeySize) { - mKemPointFormat = kemPointFormat; - mKemKdfAlgorithm = kemKdfAlgorithm; - mDemCipherTransformation = demCipherTransformation; - mDemCipherKeySize = demCipherKeySize; - mDemMacAlgorithm = demMacAlgorithm; - mDemMacKeySize = demMacKeySize; - } - - /** - * Returns KEM EC point wire format or {@link #POINT_FORMAT_UNSPECIFIED} if not specified. - */ - public @PointFormatEnum int getKemPointFormat() { - return mKemPointFormat; - } - - /** - * Returns KEM KDF algorithm (e.g., {@code HKDFwithSHA256} or {@code KDF1withSHA1}) or - * {@code null} if not specified. - */ - @Nullable - public String getKemKdfAlgorithm() { - return mKemKdfAlgorithm; - } - - /** - * Returns DEM {@link Cipher} transformation (e.g., {@code AES/GCM/NoPadding} or - * {@code AES/CBC/PKCS7Padding}) or {@code null} if not specified. - * - * @see Cipher#getInstance(String) - * @see #getDemCipherKeySize() - */ - @Nullable - public String getDemCipherTransformation() { - return mDemCipherTransformation; - } - - /** - * Returns DEM {@link Cipher} key size in bits. - * - * @see #getDemCipherTransformation() - */ - public int getDemCipherKeySize() { - return mDemCipherKeySize; - } - - /** - * Returns DEM {@link Mac} algorithm (e.g., {@code HmacSHA256} or {@code HmacSHA1}) or - * {@code null} if not specified. - * - * @see Mac#getInstance(String) - * @see #getDemMacKeySize() - */ - @Nullable - public String getDemMacAlgorithm() { - return mDemMacAlgorithm; - } - - /** - * Returns DEM {@link Mac} key size in bits. - * - * @see #getDemCipherTransformation() - */ - public int getDemMacKeySize() { - return mDemMacKeySize; - } - - /** - * Builder of {@link EcIesParameterSpec}. - */ - public static class Builder { - private @PointFormatEnum int mKemPointFormat = POINT_FORMAT_UNSPECIFIED; - private String mKemKdfAlgorithm; - private String mDemCipherTransformation; - private int mDemCipherKeySize = 128; - private String mDemMacAlgorithm; - private int mDemMacKeySize = -1; - - /** - * Sets KEM EC point wire format. - */ - public Builder setKemPointFormat(@PointFormatEnum int pointFormat) { - mKemPointFormat = pointFormat; - return this; - } - - /** - * Sets KEM KDF algorithm. For example, {@code HKDFwithSHA256}, {@code KDF2withSHA256}, or - * {@code KDF1withSHA1}. - */ - @NonNull - public Builder setKemKdfAlgorithm(@Nullable String algorithm) { - mKemKdfAlgorithm = algorithm; - return this; - } - - /** - * Sets DEM {@link Cipher} transformation. For example, {@code AES/GCM/NoPadding}, - * {@code AES/CBC/PKCS7Padding} or {@code AES/CTR/NoPadding}. - * - * @see Cipher#getInstance(String) - */ - @NonNull - public Builder setDemCipherTransformation(@Nullable String transformation) { - mDemCipherTransformation = transformation; - return this; - } - - /** - * Returns DEM {@link Cipher} key size in bits. - * - * <p>The default value is {@code 128} bits. - * - * @see #setDemCipherTransformation(String) - */ - @NonNull - public Builder setDemCipherKeySize(int sizeBits) { - mDemCipherKeySize = sizeBits; - return this; - } - - /** - * Sets DEM {@link Mac} algorithm. For example, {@code HmacSHA256} or {@code HmacSHA1}. - * - * @see Mac#getInstance(String) - */ - @NonNull - public Builder setDemMacAlgorithm(@Nullable String algorithm) { - mDemMacAlgorithm = algorithm; - return this; - } - - /** - * Sets DEM {@link Mac} key size in bits. - * - * <p>By default, {@code Mac} key size is the same as the {@code Cipher} key size. - * - * @see #setDemCipherKeySize(int) - */ - @NonNull - public Builder setDemMacKeySize(int sizeBits) { - mDemMacKeySize = sizeBits; - return this; - } - - /** - * Returns a new {@link EcIesParameterSpec} based on the current state of this builder. - */ - @NonNull - public EcIesParameterSpec build() { - int demMacKeySize = (mDemMacKeySize != -1) ? mDemMacKeySize : mDemCipherKeySize; - return new EcIesParameterSpec( - mKemPointFormat, - mKemKdfAlgorithm, - mDemCipherTransformation, - mDemCipherKeySize, - mDemMacAlgorithm, - demMacKeySize - ); - } - } -} |