diff options
Diffstat (limited to 'core/src/main/java/org/spongycastle/crypto/prng/drbg')
7 files changed, 1480 insertions, 0 deletions
diff --git a/core/src/main/java/org/spongycastle/crypto/prng/drbg/CTRSP800DRBG.java b/core/src/main/java/org/spongycastle/crypto/prng/drbg/CTRSP800DRBG.java new file mode 100644 index 00000000..26316685 --- /dev/null +++ b/core/src/main/java/org/spongycastle/crypto/prng/drbg/CTRSP800DRBG.java @@ -0,0 +1,478 @@ +package org.spongycastle.crypto.prng.drbg; + +import org.spongycastle.crypto.BlockCipher; +import org.spongycastle.crypto.params.KeyParameter; +import org.spongycastle.crypto.prng.EntropySource; +import org.spongycastle.util.Arrays; +import org.spongycastle.util.encoders.Hex; + +/** + * A SP800-90A CTR DRBG. + */ +public class CTRSP800DRBG + implements SP80090DRBG +{ + private static final long TDEA_RESEED_MAX = 1L << (32 - 1); + private static final long AES_RESEED_MAX = 1L << (48 - 1); + private static final int TDEA_MAX_BITS_REQUEST = 1 << (13 - 1); + private static final int AES_MAX_BITS_REQUEST = 1 << (19 - 1); + + private EntropySource _entropySource; + private BlockCipher _engine; + private int _keySizeInBits; + private int _seedLength; + + // internal state + private byte[] _Key; + private byte[] _V; + private long _reseedCounter = 0; + private boolean _isTDEA = false; + + /** + * Construct a SP800-90A CTR DRBG. + * <p> + * Minimum entropy requirement is the security strength requested. + * </p> + * @param engine underlying block cipher to use to support DRBG + * @param keySizeInBits size of the key to use with the block cipher. + * @param securityStrength security strength required (in bits) + * @param entropySource source of entropy to use for seeding/reseeding. + * @param personalizationString personalization string to distinguish this DRBG (may be null). + * @param nonce nonce to further distinguish this DRBG (may be null). + */ + public CTRSP800DRBG(BlockCipher engine, int keySizeInBits, int securityStrength, EntropySource entropySource, byte[] personalizationString, byte[] nonce) + { + _entropySource = entropySource; + _engine = engine; + + _keySizeInBits = keySizeInBits; + _seedLength = keySizeInBits + engine.getBlockSize() * 8; + _isTDEA = isTDEA(engine); + + if (securityStrength > 256) + { + throw new IllegalArgumentException("Requested security strength is not supported by the derivation function"); + } + + if (getMaxSecurityStrength(engine, keySizeInBits) < securityStrength) + { + throw new IllegalArgumentException("Requested security strength is not supported by block cipher and key size"); + } + + if (entropySource.entropySize() < securityStrength) + { + throw new IllegalArgumentException("Not enough entropy for security strength required"); + } + + byte[] entropy = entropySource.getEntropy(); // Get_entropy_input + + CTR_DRBG_Instantiate_algorithm(entropy, nonce, personalizationString); + } + + private void CTR_DRBG_Instantiate_algorithm(byte[] entropy, byte[] nonce, + byte[] personalisationString) + { + byte[] seedMaterial = Arrays.concatenate(entropy, nonce, personalisationString); + byte[] seed = Block_Cipher_df(seedMaterial, _seedLength); + + int outlen = _engine.getBlockSize(); + + _Key = new byte[(_keySizeInBits + 7) / 8]; + _V = new byte[outlen]; + + // _Key & _V are modified by this call + CTR_DRBG_Update(seed, _Key, _V); + + _reseedCounter = 1; + } + + private void CTR_DRBG_Update(byte[] seed, byte[] key, byte[] v) + { + byte[] temp = new byte[seed.length]; + byte[] outputBlock = new byte[_engine.getBlockSize()]; + + int i=0; + int outLen = _engine.getBlockSize(); + + _engine.init(true, new KeyParameter(expandKey(key))); + while (i*outLen < seed.length) + { + addOneTo(v); + _engine.processBlock(v, 0, outputBlock, 0); + + int bytesToCopy = ((temp.length - i * outLen) > outLen) + ? outLen : (temp.length - i * outLen); + + System.arraycopy(outputBlock, 0, temp, i * outLen, bytesToCopy); + ++i; + } + + XOR(temp, seed, temp, 0); + + System.arraycopy(temp, 0, key, 0, key.length); + System.arraycopy(temp, key.length, v, 0, v.length); + } + + private void CTR_DRBG_Reseed_algorithm(EntropySource entropy, byte[] additionalInput) + { + byte[] seedMaterial = Arrays.concatenate(entropy.getEntropy(), additionalInput); + + seedMaterial = Block_Cipher_df(seedMaterial, _seedLength); + + CTR_DRBG_Update(seedMaterial, _Key, _V); + + _reseedCounter = 1; + } + + private void XOR(byte[] out, byte[] a, byte[] b, int bOff) + { + for (int i=0; i< out.length; i++) + { + out[i] = (byte)(a[i] ^ b[i+bOff]); + } + } + + private void addOneTo(byte[] longer) + { + int carry = 1; + for (int i = 1; i <= longer.length; i++) // warning + { + int res = (longer[longer.length - i] & 0xff) + carry; + carry = (res > 0xff) ? 1 : 0; + longer[longer.length - i] = (byte)res; + } + } + + // -- Internal state migration --- + + private static final byte[] K_BITS = Hex.decode("000102030405060708090A0B0C0D0E0F101112131415161718191A1B1C1D1E1F"); + + // 1. If (number_of_bits_to_return > max_number_of_bits), then return an + // ERROR_FLAG. + // 2. L = len (input_string)/8. + // 3. N = number_of_bits_to_return/8. + // Comment: L is the bitstring represention of + // the integer resulting from len (input_string)/8. + // L shall be represented as a 32-bit integer. + // + // Comment : N is the bitstring represention of + // the integer resulting from + // number_of_bits_to_return/8. N shall be + // represented as a 32-bit integer. + // + // 4. S = L || N || input_string || 0x80. + // 5. While (len (S) mod outlen) + // Comment : Pad S with zeros, if necessary. + // 0, S = S || 0x00. + // + // Comment : Compute the starting value. + // 6. temp = the Null string. + // 7. i = 0. + // 8. K = Leftmost keylen bits of 0x00010203...1D1E1F. + // 9. While len (temp) < keylen + outlen, do + // + // IV = i || 0outlen - len (i). + // + // 9.1 + // + // temp = temp || BCC (K, (IV || S)). + // + // 9.2 + // + // i = i + 1. + // + // 9.3 + // + // Comment : i shall be represented as a 32-bit + // integer, i.e., len (i) = 32. + // + // Comment: The 32-bit integer represenation of + // i is padded with zeros to outlen bits. + // + // Comment: Compute the requested number of + // bits. + // + // 10. K = Leftmost keylen bits of temp. + // + // 11. X = Next outlen bits of temp. + // + // 12. temp = the Null string. + // + // 13. While len (temp) < number_of_bits_to_return, do + // + // 13.1 X = Block_Encrypt (K, X). + // + // 13.2 temp = temp || X. + // + // 14. requested_bits = Leftmost number_of_bits_to_return of temp. + // + // 15. Return SUCCESS and requested_bits. + private byte[] Block_Cipher_df(byte[] inputString, int bitLength) + { + int outLen = _engine.getBlockSize(); + int L = inputString.length; // already in bytes + int N = bitLength / 8; + // 4 S = L || N || inputstring || 0x80 + int sLen = 4 + 4 + L + 1; + int blockLen = ((sLen + outLen - 1) / outLen) * outLen; + byte[] S = new byte[blockLen]; + copyIntToByteArray(S, L, 0); + copyIntToByteArray(S, N, 4); + System.arraycopy(inputString, 0, S, 8, L); + S[8 + L] = (byte)0x80; + // S already padded with zeros + + byte[] temp = new byte[_keySizeInBits / 8 + outLen]; + byte[] bccOut = new byte[outLen]; + + byte[] IV = new byte[outLen]; + + int i = 0; + byte[] K = new byte[_keySizeInBits / 8]; + System.arraycopy(K_BITS, 0, K, 0, K.length); + + while (i*outLen*8 < _keySizeInBits + outLen *8) + { + copyIntToByteArray(IV, i, 0); + BCC(bccOut, K, IV, S); + + int bytesToCopy = ((temp.length - i * outLen) > outLen) + ? outLen + : (temp.length - i * outLen); + + System.arraycopy(bccOut, 0, temp, i * outLen, bytesToCopy); + ++i; + } + + byte[] X = new byte[outLen]; + System.arraycopy(temp, 0, K, 0, K.length); + System.arraycopy(temp, K.length, X, 0, X.length); + + temp = new byte[bitLength / 2]; + + i = 0; + _engine.init(true, new KeyParameter(expandKey(K))); + + while (i * outLen < temp.length) + { + _engine.processBlock(X, 0, X, 0); + + int bytesToCopy = ((temp.length - i * outLen) > outLen) + ? outLen + : (temp.length - i * outLen); + + System.arraycopy(X, 0, temp, i * outLen, bytesToCopy); + i++; + } + + return temp; + } + + /* + * 1. chaining_value = 0^outlen + * . Comment: Set the first chaining value to outlen zeros. + * 2. n = len (data)/outlen. + * 3. Starting with the leftmost bits of data, split the data into n blocks of outlen bits + * each, forming block(1) to block(n). + * 4. For i = 1 to n do + * 4.1 input_block = chaining_value ^ block(i) . + * 4.2 chaining_value = Block_Encrypt (Key, input_block). + * 5. output_block = chaining_value. + * 6. Return output_block. + */ + private void BCC(byte[] bccOut, byte[] k, byte[] iV, byte[] data) + { + int outlen = _engine.getBlockSize(); + byte[] chainingValue = new byte[outlen]; // initial values = 0 + int n = data.length / outlen; + + byte[] inputBlock = new byte[outlen]; + + _engine.init(true, new KeyParameter(expandKey(k))); + + _engine.processBlock(iV, 0, chainingValue, 0); + + for (int i = 0; i < n; i++) + { + XOR(inputBlock, chainingValue, data, i*outlen); + _engine.processBlock(inputBlock, 0, chainingValue, 0); + } + + System.arraycopy(chainingValue, 0, bccOut, 0, bccOut.length); + } + + private void copyIntToByteArray(byte[] buf, int value, int offSet) + { + buf[offSet + 0] = ((byte)(value >> 24)); + buf[offSet + 1] = ((byte)(value >> 16)); + buf[offSet + 2] = ((byte)(value >> 8)); + buf[offSet + 3] = ((byte)(value)); + } + + /** + * Return the block size (in bits) of the DRBG. + * + * @return the number of bits produced on each internal round of the DRBG. + */ + public int getBlockSize() + { + return _V.length * 8; + } + + /** + * Populate a passed in array with random data. + * + * @param output output array for generated bits. + * @param additionalInput additional input to be added to the DRBG in this step. + * @param predictionResistant true if a reseed should be forced, false otherwise. + * + * @return number of bits generated, -1 if a reseed required. + */ + public int generate(byte[] output, byte[] additionalInput, boolean predictionResistant) + { + if (_isTDEA) + { + if (_reseedCounter > TDEA_RESEED_MAX) + { + return -1; + } + + if (Utils.isTooLarge(output, TDEA_MAX_BITS_REQUEST / 8)) + { + throw new IllegalArgumentException("Number of bits per request limited to " + TDEA_MAX_BITS_REQUEST); + } + } + else + { + if (_reseedCounter > AES_RESEED_MAX) + { + return -1; + } + + if (Utils.isTooLarge(output, AES_MAX_BITS_REQUEST / 8)) + { + throw new IllegalArgumentException("Number of bits per request limited to " + AES_MAX_BITS_REQUEST); + } + } + + if (predictionResistant) + { + CTR_DRBG_Reseed_algorithm(_entropySource, additionalInput); + additionalInput = null; + } + + if (additionalInput != null) + { + additionalInput = Block_Cipher_df(additionalInput, _seedLength); + CTR_DRBG_Update(additionalInput, _Key, _V); + } + else + { + additionalInput = new byte[_seedLength]; + } + + byte[] out = new byte[_V.length]; + + _engine.init(true, new KeyParameter(expandKey(_Key))); + + for (int i = 0; i < output.length / out.length; i++) + { + addOneTo(_V); + + _engine.processBlock(_V, 0, out, 0); + + int bytesToCopy = ((output.length - i * out.length) > out.length) + ? out.length + : (output.length - i * _V.length); + + System.arraycopy(out, 0, output, i * out.length, bytesToCopy); + } + + CTR_DRBG_Update(additionalInput, _Key, _V); + + _reseedCounter++; + + return output.length * 8; + } + + /** + * Reseed the DRBG. + * + * @param additionalInput additional input to be added to the DRBG in this step. + */ + public void reseed(byte[] additionalInput) + { + CTR_DRBG_Reseed_algorithm(_entropySource, additionalInput); + } + + private boolean isTDEA(BlockCipher cipher) + { + return cipher.getAlgorithmName().equals("DESede") || cipher.getAlgorithmName().equals("TDEA"); + } + + private int getMaxSecurityStrength(BlockCipher cipher, int keySizeInBits) + { + if (isTDEA(cipher) && keySizeInBits == 168) + { + return 112; + } + if (cipher.getAlgorithmName().equals("AES")) + { + return keySizeInBits; + } + + return -1; + } + + byte[] expandKey(byte[] key) + { + if (_isTDEA) + { + // expand key to 192 bits. + byte[] tmp = new byte[24]; + + padKey(key, 0, tmp, 0); + padKey(key, 7, tmp, 8); + padKey(key, 14, tmp, 16); + + return tmp; + } + else + { + return key; + } + } + + /** + * Pad out a key for TDEA, setting odd parity for each byte. + * + * @param keyMaster + * @param keyOff + * @param tmp + * @param tmpOff + */ + private void padKey(byte[] keyMaster, int keyOff, byte[] tmp, int tmpOff) + { + tmp[tmpOff + 0] = (byte)(keyMaster[keyOff + 0] & 0xfe); + tmp[tmpOff + 1] = (byte)((keyMaster[keyOff + 0] << 7) | ((keyMaster[keyOff + 1] & 0xfc) >>> 1)); + tmp[tmpOff + 2] = (byte)((keyMaster[keyOff + 1] << 6) | ((keyMaster[keyOff + 2] & 0xf8) >>> 2)); + tmp[tmpOff + 3] = (byte)((keyMaster[keyOff + 2] << 5) | ((keyMaster[keyOff + 3] & 0xf0) >>> 3)); + tmp[tmpOff + 4] = (byte)((keyMaster[keyOff + 3] << 4) | ((keyMaster[keyOff + 4] & 0xe0) >>> 4)); + tmp[tmpOff + 5] = (byte)((keyMaster[keyOff + 4] << 3) | ((keyMaster[keyOff + 5] & 0xc0) >>> 5)); + tmp[tmpOff + 6] = (byte)((keyMaster[keyOff + 5] << 2) | ((keyMaster[keyOff + 6] & 0x80) >>> 6)); + tmp[tmpOff + 7] = (byte)(keyMaster[keyOff + 6] << 1); + + for (int i = tmpOff; i <= tmpOff + 7; i++) + { + int b = tmp[i]; + tmp[i] = (byte)((b & 0xfe) | + ((((b >> 1) ^ + (b >> 2) ^ + (b >> 3) ^ + (b >> 4) ^ + (b >> 5) ^ + (b >> 6) ^ + (b >> 7)) ^ 0x01) & 0x01)); + } + } +} diff --git a/core/src/main/java/org/spongycastle/crypto/prng/drbg/DualECPoints.java b/core/src/main/java/org/spongycastle/crypto/prng/drbg/DualECPoints.java new file mode 100644 index 00000000..251b319f --- /dev/null +++ b/core/src/main/java/org/spongycastle/crypto/prng/drbg/DualECPoints.java @@ -0,0 +1,82 @@ +package org.spongycastle.crypto.prng.drbg; + +import org.spongycastle.math.ec.ECPoint; + +/** + * General class for providing point pairs for use with DualEC DRBG. See NIST SP 800-90A for further details. + */ +public class DualECPoints +{ + private final ECPoint p; + private final ECPoint q; + private final int securityStrength; + private final int cofactor; + + /** + * Base Constructor. + * <p> + * The cofactor is used to calculate the output block length (maxOutlen) according to + * <pre> + * max_outlen = largest multiple of 8 less than ((field size in bits) - (13 + log2(cofactor)) + * </pre> + * + * @param securityStrength maximum security strength to be associated with these parameters + * @param p the P point. + * @param q the Q point. + * @param cofactor cofactor associated with the domain parameters for the point generation. + */ + public DualECPoints(int securityStrength, ECPoint p, ECPoint q, int cofactor) + { + if (!p.getCurve().equals(q.getCurve())) + { + throw new IllegalArgumentException("points need to be on the same curve"); + } + + this.securityStrength = securityStrength; + this.p = p; + this.q = q; + this.cofactor = cofactor; + } + + public int getSeedLen() + { + return p.getCurve().getFieldSize(); + } + + public int getMaxOutlen() + { + return ((p.getCurve().getFieldSize() - (13 + log2(cofactor))) / 8) * 8; + } + + public ECPoint getP() + { + return p; + } + + public ECPoint getQ() + { + return q; + } + + public int getSecurityStrength() + { + return securityStrength; + } + + public int getCofactor() + { + return cofactor; + } + + private static int log2(int value) + { + int log = 0; + + while ((value >>= 1) != 0) + { + log++; + } + + return log; + } +} diff --git a/core/src/main/java/org/spongycastle/crypto/prng/drbg/DualECSP800DRBG.java b/core/src/main/java/org/spongycastle/crypto/prng/drbg/DualECSP800DRBG.java new file mode 100644 index 00000000..239ffe57 --- /dev/null +++ b/core/src/main/java/org/spongycastle/crypto/prng/drbg/DualECSP800DRBG.java @@ -0,0 +1,320 @@ +package org.spongycastle.crypto.prng.drbg; + +import java.math.BigInteger; + +import org.spongycastle.asn1.nist.NISTNamedCurves; +import org.spongycastle.crypto.Digest; +import org.spongycastle.crypto.prng.EntropySource; +import org.spongycastle.math.ec.ECCurve; +import org.spongycastle.math.ec.ECMultiplier; +import org.spongycastle.math.ec.ECPoint; +import org.spongycastle.math.ec.FixedPointCombMultiplier; +import org.spongycastle.util.Arrays; +import org.spongycastle.util.BigIntegers; + +/** + * A SP800-90A Dual EC DRBG. + */ +public class DualECSP800DRBG + implements SP80090DRBG +{ + /* + * Default P, Q values for each curve + */ + private static final BigInteger p256_Px = new BigInteger("6b17d1f2e12c4247f8bce6e563a440f277037d812deb33a0f4a13945d898c296", 16); + private static final BigInteger p256_Py = new BigInteger("4fe342e2fe1a7f9b8ee7eb4a7c0f9e162bce33576b315ececbb6406837bf51f5", 16); + private static final BigInteger p256_Qx = new BigInteger("c97445f45cdef9f0d3e05e1e585fc297235b82b5be8ff3efca67c59852018192", 16); + private static final BigInteger p256_Qy = new BigInteger("b28ef557ba31dfcbdd21ac46e2a91e3c304f44cb87058ada2cb815151e610046", 16); + + private static final BigInteger p384_Px = new BigInteger("aa87ca22be8b05378eb1c71ef320ad746e1d3b628ba79b9859f741e082542a385502f25dbf55296c3a545e3872760ab7", 16); + private static final BigInteger p384_Py = new BigInteger("3617de4a96262c6f5d9e98bf9292dc29f8f41dbd289a147ce9da3113b5f0b8c00a60b1ce1d7e819d7a431d7c90ea0e5f", 16); + private static final BigInteger p384_Qx = new BigInteger("8e722de3125bddb05580164bfe20b8b432216a62926c57502ceede31c47816edd1e89769124179d0b695106428815065", 16); + private static final BigInteger p384_Qy = new BigInteger("023b1660dd701d0839fd45eec36f9ee7b32e13b315dc02610aa1b636e346df671f790f84c5e09b05674dbb7e45c803dd", 16); + + private static final BigInteger p521_Px = new BigInteger("c6858e06b70404e9cd9e3ecb662395b4429c648139053fb521f828af606b4d3dbaa14b5e77efe75928fe1dc127a2ffa8de3348b3c1856a429bf97e7e31c2e5bd66", 16); + private static final BigInteger p521_Py = new BigInteger("11839296a789a3bc0045c8a5fb42c7d1bd998f54449579b446817afbd17273e662c97ee72995ef42640c550b9013fad0761353c7086a272c24088be94769fd16650", 16); + private static final BigInteger p521_Qx = new BigInteger("1b9fa3e518d683c6b65763694ac8efbaec6fab44f2276171a42726507dd08add4c3b3f4c1ebc5b1222ddba077f722943b24c3edfa0f85fe24d0c8c01591f0be6f63", 16); + private static final BigInteger p521_Qy = new BigInteger("1f3bdba585295d9a1110d1df1f9430ef8442c5018976ff3437ef91b81dc0b8132c8d5c39c32d0e004a3092b7d327c0e7a4d26d2c7b69b58f9066652911e457779de", 16); + + private static final DualECPoints[] nistPoints; + + static + { + nistPoints = new DualECPoints[3]; + + ECCurve.Fp curve = (ECCurve.Fp)NISTNamedCurves.getByName("P-256").getCurve(); + + nistPoints[0] = new DualECPoints(128, curve.createPoint(p256_Px, p256_Py), curve.createPoint(p256_Qx, p256_Qy), 1); + + curve = (ECCurve.Fp)NISTNamedCurves.getByName("P-384").getCurve(); + + nistPoints[1] = new DualECPoints(192, curve.createPoint(p384_Px, p384_Py), curve.createPoint(p384_Qx, p384_Qy), 1); + + curve = (ECCurve.Fp)NISTNamedCurves.getByName("P-521").getCurve(); + + nistPoints[2] = new DualECPoints(256, curve.createPoint(p521_Px, p521_Py), curve.createPoint(p521_Qx, p521_Qy), 1); + } + + + private static final long RESEED_MAX = 1L << (32 - 1); + private static final int MAX_ADDITIONAL_INPUT = 1 << (13 - 1); + private static final int MAX_ENTROPY_LENGTH = 1 << (13 - 1); + private static final int MAX_PERSONALIZATION_STRING = 1 << (13 -1); + + private Digest _digest; + private long _reseedCounter; + private EntropySource _entropySource; + private int _securityStrength; + private int _seedlen; + private int _outlen; + private ECCurve.Fp _curve; + private ECPoint _P; + private ECPoint _Q; + private byte[] _s; + private int _sLength; + private ECMultiplier _fixedPointMultiplier = new FixedPointCombMultiplier(); + + /** + * Construct a SP800-90A Dual EC DRBG. + * <p> + * Minimum entropy requirement is the security strength requested. + * </p> + * @param digest source digest to use with the DRB stream. + * @param securityStrength security strength required (in bits) + * @param entropySource source of entropy to use for seeding/reseeding. + * @param personalizationString personalization string to distinguish this DRBG (may be null). + * @param nonce nonce to further distinguish this DRBG (may be null). + */ + public DualECSP800DRBG(Digest digest, int securityStrength, EntropySource entropySource, byte[] personalizationString, byte[] nonce) + { + this(nistPoints, digest, securityStrength, entropySource, personalizationString, nonce); + } + + /** + * Construct a SP800-90A Dual EC DRBG. + * <p> + * Minimum entropy requirement is the security strength requested. + * </p> + * @param pointSet an array of points to choose from, in order of increasing security strength + * @param digest source digest to use with the DRB stream. + * @param securityStrength security strength required (in bits) + * @param entropySource source of entropy to use for seeding/reseeding. + * @param personalizationString personalization string to distinguish this DRBG (may be null). + * @param nonce nonce to further distinguish this DRBG (may be null). + */ + public DualECSP800DRBG(DualECPoints[] pointSet, Digest digest, int securityStrength, EntropySource entropySource, byte[] personalizationString, byte[] nonce) + { + _digest = digest; + _entropySource = entropySource; + _securityStrength = securityStrength; + + if (Utils.isTooLarge(personalizationString, MAX_PERSONALIZATION_STRING / 8)) + { + throw new IllegalArgumentException("Personalization string too large"); + } + + if (entropySource.entropySize() < securityStrength || entropySource.entropySize() > MAX_ENTROPY_LENGTH) + { + throw new IllegalArgumentException("EntropySource must provide between " + securityStrength + " and " + MAX_ENTROPY_LENGTH + " bits"); + } + + byte[] entropy = entropySource.getEntropy(); + byte[] seedMaterial = Arrays.concatenate(entropy, nonce, personalizationString); + + for (int i = 0; i != pointSet.length; i++) + { + if (securityStrength <= pointSet[i].getSecurityStrength()) + { + if (Utils.getMaxSecurityStrength(digest) < pointSet[i].getSecurityStrength()) + { + throw new IllegalArgumentException("Requested security strength is not supported by digest"); + } + _seedlen = pointSet[i].getSeedLen(); + _outlen = pointSet[i].getMaxOutlen() / 8; + _P = pointSet[i].getP(); + _Q = pointSet[i].getQ(); + break; + } + } + + if (_P == null) + { + throw new IllegalArgumentException("security strength cannot be greater than 256 bits"); + } + + _s = Utils.hash_df(_digest, seedMaterial, _seedlen); + _sLength = _s.length; + + _reseedCounter = 0; + } + + /** + * Return the block size (in bits) of the DRBG. + * + * @return the number of bits produced on each internal round of the DRBG. + */ + public int getBlockSize() + { + return _outlen * 8; + } + + /** + * Populate a passed in array with random data. + * + * @param output output array for generated bits. + * @param additionalInput additional input to be added to the DRBG in this step. + * @param predictionResistant true if a reseed should be forced, false otherwise. + * + * @return number of bits generated, -1 if a reseed required. + */ + public int generate(byte[] output, byte[] additionalInput, boolean predictionResistant) + { + int numberOfBits = output.length*8; + int m = output.length / _outlen; + + if (Utils.isTooLarge(additionalInput, MAX_ADDITIONAL_INPUT / 8)) + { + throw new IllegalArgumentException("Additional input too large"); + } + + if (_reseedCounter + m > RESEED_MAX) + { + return -1; + } + + if (predictionResistant) + { + reseed(additionalInput); + additionalInput = null; + } + + BigInteger s; + + if (additionalInput != null) + { + // Note: we ignore the use of pad8 on the additional input as we mandate byte arrays for it. + additionalInput = Utils.hash_df(_digest, additionalInput, _seedlen); + s = new BigInteger(1, xor(_s, additionalInput)); + } + else + { + s = new BigInteger(1, _s); + } + + // make sure we start with a clean output array. + Arrays.fill(output, (byte)0); + + int outOffset = 0; + + for (int i = 0; i < m; i++) + { + s = getScalarMultipleXCoord(_P, s); + + //System.err.println("S: " + new String(Hex.encode(_s))); + + byte[] r = getScalarMultipleXCoord(_Q, s).toByteArray(); + + if (r.length > _outlen) + { + System.arraycopy(r, r.length - _outlen, output, outOffset, _outlen); + } + else + { + System.arraycopy(r, 0, output, outOffset + (_outlen - r.length), r.length); + } + + //System.err.println("R: " + new String(Hex.encode(r))); + outOffset += _outlen; + + _reseedCounter++; + } + + if (outOffset < output.length) + { + s = getScalarMultipleXCoord(_P, s); + + byte[] r = getScalarMultipleXCoord(_Q, s).toByteArray(); + + int required = output.length - outOffset; + + if (r.length > _outlen) + { + System.arraycopy(r, r.length - _outlen, output, outOffset, required); + } + else + { + System.arraycopy(r, 0, output, outOffset + (_outlen - r.length), required); + } + + _reseedCounter++; + } + + // Need to preserve length of S as unsigned int. + _s = BigIntegers.asUnsignedByteArray(_sLength, getScalarMultipleXCoord(_P, s)); + + return numberOfBits; + } + + /** + * Reseed the DRBG. + * + * @param additionalInput additional input to be added to the DRBG in this step. + */ + public void reseed(byte[] additionalInput) + { + if (Utils.isTooLarge(additionalInput, MAX_ADDITIONAL_INPUT / 8)) + { + throw new IllegalArgumentException("Additional input string too large"); + } + + byte[] entropy = _entropySource.getEntropy(); + byte[] seedMaterial = Arrays.concatenate(pad8(_s, _seedlen), entropy, additionalInput); + + _s = Utils.hash_df(_digest, seedMaterial, _seedlen); + + _reseedCounter = 0; + } + + private byte[] xor(byte[] a, byte[] b) + { + if (b == null) + { + return a; + } + + byte[] rv = new byte[a.length]; + + for (int i = 0; i != rv.length; i++) + { + rv[i] = (byte)(a[i] ^ b[i]); + } + + return rv; + } + + // Note: works in place + private byte[] pad8(byte[] s, int seedlen) + { + if (seedlen % 8 == 0) + { + return s; + } + + int shift = 8 - (seedlen % 8); + int carry = 0; + + for (int i = s.length - 1; i >= 0; i--) + { + int b = s[i] & 0xff; + s[i] = (byte)((b << shift) | (carry >> (8 - shift))); + carry = b; + } + + return s; + } + + private BigInteger getScalarMultipleXCoord(ECPoint p, BigInteger s) + { + return _fixedPointMultiplier.multiply(p, s).normalize().getAffineXCoord().toBigInteger(); + } +} diff --git a/core/src/main/java/org/spongycastle/crypto/prng/drbg/HMacSP800DRBG.java b/core/src/main/java/org/spongycastle/crypto/prng/drbg/HMacSP800DRBG.java new file mode 100644 index 00000000..6d2d4247 --- /dev/null +++ b/core/src/main/java/org/spongycastle/crypto/prng/drbg/HMacSP800DRBG.java @@ -0,0 +1,181 @@ +package org.spongycastle.crypto.prng.drbg; + +import org.spongycastle.crypto.Mac; +import org.spongycastle.crypto.params.KeyParameter; +import org.spongycastle.crypto.prng.EntropySource; +import org.spongycastle.util.Arrays; + +/** + * A SP800-90A HMAC DRBG. + */ +public class HMacSP800DRBG + implements SP80090DRBG +{ + private final static long RESEED_MAX = 1L << (48 - 1); + private final static int MAX_BITS_REQUEST = 1 << (19 - 1); + + private byte[] _K; + private byte[] _V; + private long _reseedCounter; + private EntropySource _entropySource; + private Mac _hMac; + + /** + * Construct a SP800-90A Hash DRBG. + * <p> + * Minimum entropy requirement is the security strength requested. + * </p> + * @param hMac Hash MAC to base the DRBG on. + * @param securityStrength security strength required (in bits) + * @param entropySource source of entropy to use for seeding/reseeding. + * @param personalizationString personalization string to distinguish this DRBG (may be null). + * @param nonce nonce to further distinguish this DRBG (may be null). + */ + public HMacSP800DRBG(Mac hMac, int securityStrength, EntropySource entropySource, byte[] personalizationString, byte[] nonce) + { + if (securityStrength > Utils.getMaxSecurityStrength(hMac)) + { + throw new IllegalArgumentException("Requested security strength is not supported by the derivation function"); + } + + if (entropySource.entropySize() < securityStrength) + { + throw new IllegalArgumentException("Not enough entropy for security strength required"); + } + + _entropySource = entropySource; + _hMac = hMac; + + byte[] entropy = entropySource.getEntropy(); + byte[] seedMaterial = Arrays.concatenate(entropy, nonce, personalizationString); + + _K = new byte[hMac.getMacSize()]; + _V = new byte[_K.length]; + Arrays.fill(_V, (byte)1); + + hmac_DRBG_Update(seedMaterial); + + _reseedCounter = 1; + } + + private void hmac_DRBG_Update(byte[] seedMaterial) + { + hmac_DRBG_Update_Func(seedMaterial, (byte)0x00); + if (seedMaterial != null) + { + hmac_DRBG_Update_Func(seedMaterial, (byte)0x01); + } + } + + private void hmac_DRBG_Update_Func(byte[] seedMaterial, byte vValue) + { + _hMac.init(new KeyParameter(_K)); + + _hMac.update(_V, 0, _V.length); + _hMac.update(vValue); + + if (seedMaterial != null) + { + _hMac.update(seedMaterial, 0, seedMaterial.length); + } + + _hMac.doFinal(_K, 0); + + _hMac.init(new KeyParameter(_K)); + _hMac.update(_V, 0, _V.length); + + _hMac.doFinal(_V, 0); + } + + /** + * Return the block size (in bits) of the DRBG. + * + * @return the number of bits produced on each round of the DRBG. + */ + public int getBlockSize() + { + return _V.length * 8; + } + + /** + * Populate a passed in array with random data. + * + * @param output output array for generated bits. + * @param additionalInput additional input to be added to the DRBG in this step. + * @param predictionResistant true if a reseed should be forced, false otherwise. + * + * @return number of bits generated, -1 if a reseed required. + */ + public int generate(byte[] output, byte[] additionalInput, boolean predictionResistant) + { + int numberOfBits = output.length * 8; + + if (numberOfBits > MAX_BITS_REQUEST) + { + throw new IllegalArgumentException("Number of bits per request limited to " + MAX_BITS_REQUEST); + } + + if (_reseedCounter > RESEED_MAX) + { + return -1; + } + + if (predictionResistant) + { + reseed(additionalInput); + additionalInput = null; + } + + // 2. + if (additionalInput != null) + { + hmac_DRBG_Update(additionalInput); + } + + // 3. + byte[] rv = new byte[output.length]; + + int m = output.length / _V.length; + + _hMac.init(new KeyParameter(_K)); + + for (int i = 0; i < m; i++) + { + _hMac.update(_V, 0, _V.length); + _hMac.doFinal(_V, 0); + + System.arraycopy(_V, 0, rv, i * _V.length, _V.length); + } + + if (m * _V.length < rv.length) + { + _hMac.update(_V, 0, _V.length); + _hMac.doFinal(_V, 0); + + System.arraycopy(_V, 0, rv, m * _V.length, rv.length - (m * _V.length)); + } + + hmac_DRBG_Update(additionalInput); + + _reseedCounter++; + + System.arraycopy(rv, 0, output, 0, output.length); + + return numberOfBits; + } + + /** + * Reseed the DRBG. + * + * @param additionalInput additional input to be added to the DRBG in this step. + */ + public void reseed(byte[] additionalInput) + { + byte[] entropy = _entropySource.getEntropy(); + byte[] seedMaterial = Arrays.concatenate(entropy, additionalInput); + + hmac_DRBG_Update(seedMaterial); + + _reseedCounter = 1; + } +} diff --git a/core/src/main/java/org/spongycastle/crypto/prng/drbg/HashSP800DRBG.java b/core/src/main/java/org/spongycastle/crypto/prng/drbg/HashSP800DRBG.java new file mode 100644 index 00000000..13498046 --- /dev/null +++ b/core/src/main/java/org/spongycastle/crypto/prng/drbg/HashSP800DRBG.java @@ -0,0 +1,284 @@ +package org.spongycastle.crypto.prng.drbg; + +import java.util.Hashtable; + +import org.spongycastle.crypto.Digest; +import org.spongycastle.crypto.prng.EntropySource; +import org.spongycastle.util.Arrays; +import org.spongycastle.util.Integers; + +/** + * A SP800-90A Hash DRBG. + */ +public class HashSP800DRBG + implements SP80090DRBG +{ + private final static byte[] ONE = { 0x01 }; + + private final static long RESEED_MAX = 1L << (48 - 1); + private final static int MAX_BITS_REQUEST = 1 << (19 - 1); + + private final static Hashtable seedlens = new Hashtable(); + + static + { + seedlens.put("SHA-1", Integers.valueOf(440)); + seedlens.put("SHA-224", Integers.valueOf(440)); + seedlens.put("SHA-256", Integers.valueOf(440)); + seedlens.put("SHA-512/256", Integers.valueOf(440)); + seedlens.put("SHA-512/224", Integers.valueOf(440)); + seedlens.put("SHA-384", Integers.valueOf(888)); + seedlens.put("SHA-512", Integers.valueOf(888)); + } + + private Digest _digest; + private byte[] _V; + private byte[] _C; + private long _reseedCounter; + private EntropySource _entropySource; + private int _securityStrength; + private int _seedLength; + + /** + * Construct a SP800-90A Hash DRBG. + * <p> + * Minimum entropy requirement is the security strength requested. + * </p> + * @param digest source digest to use for DRB stream. + * @param securityStrength security strength required (in bits) + * @param entropySource source of entropy to use for seeding/reseeding. + * @param personalizationString personalization string to distinguish this DRBG (may be null). + * @param nonce nonce to further distinguish this DRBG (may be null). + */ + public HashSP800DRBG(Digest digest, int securityStrength, EntropySource entropySource, byte[] personalizationString, byte[] nonce) + { + if (securityStrength > Utils.getMaxSecurityStrength(digest)) + { + throw new IllegalArgumentException("Requested security strength is not supported by the derivation function"); + } + + if (entropySource.entropySize() < securityStrength) + { + throw new IllegalArgumentException("Not enough entropy for security strength required"); + } + + _digest = digest; + _entropySource = entropySource; + _securityStrength = securityStrength; + _seedLength = ((Integer)seedlens.get(digest.getAlgorithmName())).intValue(); + + // 1. seed_material = entropy_input || nonce || personalization_string. + // 2. seed = Hash_df (seed_material, seedlen). + // 3. V = seed. + // 4. C = Hash_df ((0x00 || V), seedlen). Comment: Preceed V with a byte + // of zeros. + // 5. reseed_counter = 1. + // 6. Return V, C, and reseed_counter as the initial_working_state + + byte[] entropy = entropySource.getEntropy(); + byte[] seedMaterial = Arrays.concatenate(entropy, nonce, personalizationString); + byte[] seed = Utils.hash_df(_digest, seedMaterial, _seedLength); + + _V = seed; + byte[] subV = new byte[_V.length + 1]; + System.arraycopy(_V, 0, subV, 1, _V.length); + _C = Utils.hash_df(_digest, subV, _seedLength); + + _reseedCounter = 1; + } + + /** + * Return the block size (in bits) of the DRBG. + * + * @return the number of bits produced on each internal round of the DRBG. + */ + public int getBlockSize() + { + return _digest.getDigestSize() * 8; + } + + /** + * Populate a passed in array with random data. + * + * @param output output array for generated bits. + * @param additionalInput additional input to be added to the DRBG in this step. + * @param predictionResistant true if a reseed should be forced, false otherwise. + * + * @return number of bits generated, -1 if a reseed required. + */ + public int generate(byte[] output, byte[] additionalInput, boolean predictionResistant) + { + // 1. If reseed_counter > reseed_interval, then return an indication that a + // reseed is required. + // 2. If (additional_input != Null), then do + // 2.1 w = Hash (0x02 || V || additional_input). + // 2.2 V = (V + w) mod 2^seedlen + // . + // 3. (returned_bits) = Hashgen (requested_number_of_bits, V). + // 4. H = Hash (0x03 || V). + // 5. V = (V + H + C + reseed_counter) mod 2^seedlen + // . + // 6. reseed_counter = reseed_counter + 1. + // 7. Return SUCCESS, returned_bits, and the new values of V, C, and + // reseed_counter for the new_working_state. + int numberOfBits = output.length*8; + + if (numberOfBits > MAX_BITS_REQUEST) + { + throw new IllegalArgumentException("Number of bits per request limited to " + MAX_BITS_REQUEST); + } + + if (_reseedCounter > RESEED_MAX) + { + return -1; + } + + if (predictionResistant) + { + reseed(additionalInput); + additionalInput = null; + } + + // 2. + if (additionalInput != null) + { + byte[] newInput = new byte[1 + _V.length + additionalInput.length]; + newInput[0] = 0x02; + System.arraycopy(_V, 0, newInput, 1, _V.length); + // TODO: inOff / inLength + System.arraycopy(additionalInput, 0, newInput, 1 + _V.length, additionalInput.length); + byte[] w = hash(newInput); + + addTo(_V, w); + } + + // 3. + byte[] rv = hashgen(_V, numberOfBits); + + // 4. + byte[] subH = new byte[_V.length + 1]; + System.arraycopy(_V, 0, subH, 1, _V.length); + subH[0] = 0x03; + + byte[] H = hash(subH); + + // 5. + addTo(_V, H); + addTo(_V, _C); + byte[] c = new byte[4]; + c[0] = (byte)(_reseedCounter >> 24); + c[1] = (byte)(_reseedCounter >> 16); + c[2] = (byte)(_reseedCounter >> 8); + c[3] = (byte)_reseedCounter; + + addTo(_V, c); + + _reseedCounter++; + + System.arraycopy(rv, 0, output, 0, output.length); + + return numberOfBits; + } + + // this will always add the shorter length byte array mathematically to the + // longer length byte array. + // be careful.... + private void addTo(byte[] longer, byte[] shorter) + { + int carry = 0; + for (int i=1;i <= shorter.length; i++) // warning + { + int res = (longer[longer.length-i] & 0xff) + (shorter[shorter.length-i] & 0xff) + carry; + carry = (res > 0xff) ? 1 : 0; + longer[longer.length-i] = (byte)res; + } + + for (int i=shorter.length+1;i <= longer.length; i++) // warning + { + int res = (longer[longer.length-i] & 0xff) + carry; + carry = (res > 0xff) ? 1 : 0; + longer[longer.length-i] = (byte)res; + } + } + + /** + * Reseed the DRBG. + * + * @param additionalInput additional input to be added to the DRBG in this step. + */ + public void reseed(byte[] additionalInput) + { + // 1. seed_material = 0x01 || V || entropy_input || additional_input. + // + // 2. seed = Hash_df (seed_material, seedlen). + // + // 3. V = seed. + // + // 4. C = Hash_df ((0x00 || V), seedlen). + // + // 5. reseed_counter = 1. + // + // 6. Return V, C, and reseed_counter for the new_working_state. + // + // Comment: Precede with a byte of all zeros. + byte[] entropy = _entropySource.getEntropy(); + byte[] seedMaterial = Arrays.concatenate(ONE, _V, entropy, additionalInput); + byte[] seed = Utils.hash_df(_digest, seedMaterial, _seedLength); + + _V = seed; + byte[] subV = new byte[_V.length + 1]; + subV[0] = 0x00; + System.arraycopy(_V, 0, subV, 1, _V.length); + _C = Utils.hash_df(_digest, subV, _seedLength); + + _reseedCounter = 1; + } + + private byte[] hash(byte[] input) + { + byte[] hash = new byte[_digest.getDigestSize()]; + doHash(input, hash); + return hash; + } + + private void doHash(byte[] input, byte[] output) + { + _digest.update(input, 0, input.length); + _digest.doFinal(output, 0); + } + + // 1. m = [requested_number_of_bits / outlen] + // 2. data = V. + // 3. W = the Null string. + // 4. For i = 1 to m + // 4.1 wi = Hash (data). + // 4.2 W = W || wi. + // 4.3 data = (data + 1) mod 2^seedlen + // . + // 5. returned_bits = Leftmost (requested_no_of_bits) bits of W. + private byte[] hashgen(byte[] input, int lengthInBits) + { + int digestSize = _digest.getDigestSize(); + int m = (lengthInBits / 8) / digestSize; + + byte[] data = new byte[input.length]; + System.arraycopy(input, 0, data, 0, input.length); + + byte[] W = new byte[lengthInBits / 8]; + + byte[] dig = new byte[_digest.getDigestSize()]; + for (int i = 0; i <= m; i++) + { + doHash(data, dig); + + int bytesToCopy = ((W.length - i * dig.length) > dig.length) + ? dig.length + : (W.length - i * dig.length); + System.arraycopy(dig, 0, W, i * dig.length, bytesToCopy); + + addTo(data, ONE); + } + + return W; + } +}
\ No newline at end of file diff --git a/core/src/main/java/org/spongycastle/crypto/prng/drbg/SP80090DRBG.java b/core/src/main/java/org/spongycastle/crypto/prng/drbg/SP80090DRBG.java new file mode 100644 index 00000000..a1ec3b26 --- /dev/null +++ b/core/src/main/java/org/spongycastle/crypto/prng/drbg/SP80090DRBG.java @@ -0,0 +1,32 @@ +package org.spongycastle.crypto.prng.drbg; + +/** + * Interface to SP800-90A deterministic random bit generators. + */ +public interface SP80090DRBG +{ + /** + * Return the block size of the DRBG. + * + * @return the block size (in bits) produced by each round of the DRBG. + */ + int getBlockSize(); + + /** + * Populate a passed in array with random data. + * + * @param output output array for generated bits. + * @param additionalInput additional input to be added to the DRBG in this step. + * @param predictionResistant true if a reseed should be forced, false otherwise. + * + * @return number of bits generated, -1 if a reseed required. + */ + int generate(byte[] output, byte[] additionalInput, boolean predictionResistant); + + /** + * Reseed the DRBG. + * + * @param additionalInput additional input to be added to the DRBG in this step. + */ + void reseed(byte[] additionalInput); +} diff --git a/core/src/main/java/org/spongycastle/crypto/prng/drbg/Utils.java b/core/src/main/java/org/spongycastle/crypto/prng/drbg/Utils.java new file mode 100644 index 00000000..bf2626d0 --- /dev/null +++ b/core/src/main/java/org/spongycastle/crypto/prng/drbg/Utils.java @@ -0,0 +1,103 @@ +package org.spongycastle.crypto.prng.drbg; + +import java.util.Hashtable; + +import org.spongycastle.crypto.Digest; +import org.spongycastle.crypto.Mac; +import org.spongycastle.util.Integers; + +class Utils +{ + static final Hashtable maxSecurityStrengths = new Hashtable(); + + static + { + maxSecurityStrengths.put("SHA-1", Integers.valueOf(128)); + + maxSecurityStrengths.put("SHA-224", Integers.valueOf(192)); + maxSecurityStrengths.put("SHA-256", Integers.valueOf(256)); + maxSecurityStrengths.put("SHA-384", Integers.valueOf(256)); + maxSecurityStrengths.put("SHA-512", Integers.valueOf(256)); + + maxSecurityStrengths.put("SHA-512/224", Integers.valueOf(192)); + maxSecurityStrengths.put("SHA-512/256", Integers.valueOf(256)); + } + + static int getMaxSecurityStrength(Digest d) + { + return ((Integer)maxSecurityStrengths.get(d.getAlgorithmName())).intValue(); + } + + static int getMaxSecurityStrength(Mac m) + { + String name = m.getAlgorithmName(); + + return ((Integer)maxSecurityStrengths.get(name.substring(0, name.indexOf("/")))).intValue(); + } + + /** + * Used by both Dual EC and Hash. + */ + static byte[] hash_df(Digest digest, byte[] seedMaterial, int seedLength) + { + // 1. temp = the Null string. + // 2. . + // 3. counter = an 8-bit binary value representing the integer "1". + // 4. For i = 1 to len do + // Comment : In step 4.1, no_of_bits_to_return + // is used as a 32-bit string. + // 4.1 temp = temp || Hash (counter || no_of_bits_to_return || + // input_string). + // 4.2 counter = counter + 1. + // 5. requested_bits = Leftmost (no_of_bits_to_return) of temp. + // 6. Return SUCCESS and requested_bits. + byte[] temp = new byte[(seedLength + 7) / 8]; + + int len = temp.length / digest.getDigestSize(); + int counter = 1; + + byte[] dig = new byte[digest.getDigestSize()]; + + for (int i = 0; i <= len; i++) + { + digest.update((byte)counter); + + digest.update((byte)(seedLength >> 24)); + digest.update((byte)(seedLength >> 16)); + digest.update((byte)(seedLength >> 8)); + digest.update((byte)seedLength); + + digest.update(seedMaterial, 0, seedMaterial.length); + + digest.doFinal(dig, 0); + + int bytesToCopy = ((temp.length - i * dig.length) > dig.length) + ? dig.length + : (temp.length - i * dig.length); + System.arraycopy(dig, 0, temp, i * dig.length, bytesToCopy); + + counter++; + } + + // do a left shift to get rid of excess bits. + if (seedLength % 8 != 0) + { + int shift = 8 - (seedLength % 8); + int carry = 0; + + for (int i = 0; i != temp.length; i++) + { + int b = temp[i] & 0xff; + temp[i] = (byte)((b >>> shift) | (carry << (8 - shift))); + carry = b; + } + } + + return temp; + } + + static boolean isTooLarge(byte[] bytes, int maxBytes) + { + return bytes != null && bytes.length > maxBytes; + } +} |