package org.bouncycastle.crypto.tls; import java.io.ByteArrayInputStream; import java.io.IOException; import java.io.InputStream; import java.io.OutputStream; import java.math.BigInteger; import java.security.SecureRandom; import java.util.Hashtable; import org.bouncycastle.crypto.AsymmetricCipherKeyPair; import org.bouncycastle.crypto.agreement.DHBasicAgreement; import org.bouncycastle.crypto.generators.DHBasicKeyPairGenerator; import org.bouncycastle.crypto.params.DHKeyGenerationParameters; import org.bouncycastle.crypto.params.DHParameters; import org.bouncycastle.crypto.params.DHPrivateKeyParameters; import org.bouncycastle.crypto.params.DHPublicKeyParameters; import org.bouncycastle.util.BigIntegers; import org.bouncycastle.util.Integers; import org.bouncycastle.util.encoders.Hex; public class TlsDHUtils { static final BigInteger TWO = BigInteger.valueOf(2); public static final Integer EXT_negotiated_ff_dhe_groups = Integers.valueOf(ExtensionType.negotiated_ff_dhe_groups); /* * TODO[draft-ietf-tls-negotiated-ff-dhe-01] Move these groups to DHStandardGroups once reaches RFC */ private static BigInteger fromHex(String hex) { return new BigInteger(1, Hex.decode(hex)); } private static DHParameters fromSafeP(String hexP) { BigInteger p = fromHex(hexP), q = p.shiftRight(1); return new DHParameters(p, TWO, q); } private static final String draft_ffdhe2432_p = "FFFFFFFFFFFFFFFFADF85458A2BB4A9AAFDC5620273D3CF1" + "D8B9C583CE2D3695A9E13641146433FBCC939DCE249B3EF9" + "7D2FE363630C75D8F681B202AEC4617AD3DF1ED5D5FD6561" + "2433F51F5F066ED0856365553DED1AF3B557135E7F57C935" + "984F0C70E0E68B77E2A689DAF3EFE8721DF158A136ADE735" + "30ACCA4F483A797ABC0AB182B324FB61D108A94BB2C8E3FB" + "B96ADAB760D7F4681D4F42A3DE394DF4AE56EDE76372BB19" + "0B07A7C8EE0A6D709E02FCE1CDF7E2ECC03404CD28342F61" + "9172FE9CE98583FF8E4F1232EEF28183C3FE3B1B4C6FAD73" + "3BB5FCBC2EC22005C58EF1837D1683B2C6F34A26C1B2EFFA" + "886B4238611FCFDCDE355B3B6519035BBC34F4DEF99C0238" + "61B46FC9D6E6C9077AD91D2691F7F7EE598CB0FAC186D91C" + "AEFE13098533C8B3FFFFFFFFFFFFFFFF"; static final DHParameters draft_ffdhe2432 = fromSafeP(draft_ffdhe2432_p); private static final String draft_ffdhe3072_p = "FFFFFFFFFFFFFFFFADF85458A2BB4A9AAFDC5620273D3CF1" + "D8B9C583CE2D3695A9E13641146433FBCC939DCE249B3EF9" + "7D2FE363630C75D8F681B202AEC4617AD3DF1ED5D5FD6561" + "2433F51F5F066ED0856365553DED1AF3B557135E7F57C935" + "984F0C70E0E68B77E2A689DAF3EFE8721DF158A136ADE735" + "30ACCA4F483A797ABC0AB182B324FB61D108A94BB2C8E3FB" + "B96ADAB760D7F4681D4F42A3DE394DF4AE56EDE76372BB19" + "0B07A7C8EE0A6D709E02FCE1CDF7E2ECC03404CD28342F61" + "9172FE9CE98583FF8E4F1232EEF28183C3FE3B1B4C6FAD73" + "3BB5FCBC2EC22005C58EF1837D1683B2C6F34A26C1B2EFFA" + "886B4238611FCFDCDE355B3B6519035BBC34F4DEF99C0238" + "61B46FC9D6E6C9077AD91D2691F7F7EE598CB0FAC186D91C" + "AEFE130985139270B4130C93BC437944F4FD4452E2D74DD3" + "64F2E21E71F54BFF5CAE82AB9C9DF69EE86D2BC522363A0D" + "ABC521979B0DEADA1DBF9A42D5C4484E0ABCD06BFA53DDEF" + "3C1B20EE3FD59D7C25E41D2B66C62E37FFFFFFFFFFFFFFFF"; static final DHParameters draft_ffdhe3072 = fromSafeP(draft_ffdhe3072_p); private static final String draft_ffdhe4096_p = "FFFFFFFFFFFFFFFFADF85458A2BB4A9AAFDC5620273D3CF1" + "D8B9C583CE2D3695A9E13641146433FBCC939DCE249B3EF9" + "7D2FE363630C75D8F681B202AEC4617AD3DF1ED5D5FD6561" + "2433F51F5F066ED0856365553DED1AF3B557135E7F57C935" + "984F0C70E0E68B77E2A689DAF3EFE8721DF158A136ADE735" + "30ACCA4F483A797ABC0AB182B324FB61D108A94BB2C8E3FB" + "B96ADAB760D7F4681D4F42A3DE394DF4AE56EDE76372BB19" + "0B07A7C8EE0A6D709E02FCE1CDF7E2ECC03404CD28342F61" + "9172FE9CE98583FF8E4F1232EEF28183C3FE3B1B4C6FAD73" + "3BB5FCBC2EC22005C58EF1837D1683B2C6F34A26C1B2EFFA" + "886B4238611FCFDCDE355B3B6519035BBC34F4DEF99C0238" + "61B46FC9D6E6C9077AD91D2691F7F7EE598CB0FAC186D91C" + "AEFE130985139270B4130C93BC437944F4FD4452E2D74DD3" + "64F2E21E71F54BFF5CAE82AB9C9DF69EE86D2BC522363A0D" + "ABC521979B0DEADA1DBF9A42D5C4484E0ABCD06BFA53DDEF" + "3C1B20EE3FD59D7C25E41D2B669E1EF16E6F52C3164DF4FB" + "7930E9E4E58857B6AC7D5F42D69F6D187763CF1D55034004" + "87F55BA57E31CC7A7135C886EFB4318AED6A1E012D9E6832" + "A907600A918130C46DC778F971AD0038092999A333CB8B7A" + "1A1DB93D7140003C2A4ECEA9F98D0ACC0A8291CDCEC97DCF" + "8EC9B55A7F88A46B4DB5A851F44182E1C68A007E5E655F6A" + "FFFFFFFFFFFFFFFF"; static final DHParameters draft_ffdhe4096 = fromSafeP(draft_ffdhe4096_p); private static final String draft_ffdhe6144_p = "FFFFFFFFFFFFFFFFADF85458A2BB4A9AAFDC5620273D3CF1" + "D8B9C583CE2D3695A9E13641146433FBCC939DCE249B3EF9" + "7D2FE363630C75D8F681B202AEC4617AD3DF1ED5D5FD6561" + "2433F51F5F066ED0856365553DED1AF3B557135E7F57C935" + "984F0C70E0E68B77E2A689DAF3EFE8721DF158A136ADE735" + "30ACCA4F483A797ABC0AB182B324FB61D108A94BB2C8E3FB" + "B96ADAB760D7F4681D4F42A3DE394DF4AE56EDE76372BB19" + "0B07A7C8EE0A6D709E02FCE1CDF7E2ECC03404CD28342F61" + "9172FE9CE98583FF8E4F1232EEF28183C3FE3B1B4C6FAD73" + "3BB5FCBC2EC22005C58EF1837D1683B2C6F34A26C1B2EFFA" + "886B4238611FCFDCDE355B3B6519035BBC34F4DEF99C0238" + "61B46FC9D6E6C9077AD91D2691F7F7EE598CB0FAC186D91C" + "AEFE130985139270B4130C93BC437944F4FD4452E2D74DD3" + "64F2E21E71F54BFF5CAE82AB9C9DF69EE86D2BC522363A0D" + "ABC521979B0DEADA1DBF9A42D5C4484E0ABCD06BFA53DDEF" + "3C1B20EE3FD59D7C25E41D2B669E1EF16E6F52C3164DF4FB" + "7930E9E4E58857B6AC7D5F42D69F6D187763CF1D55034004" + "87F55BA57E31CC7A7135C886EFB4318AED6A1E012D9E6832" + "A907600A918130C46DC778F971AD0038092999A333CB8B7A" + "1A1DB93D7140003C2A4ECEA9F98D0ACC0A8291CDCEC97DCF" + "8EC9B55A7F88A46B4DB5A851F44182E1C68A007E5E0DD902" + "0BFD64B645036C7A4E677D2C38532A3A23BA4442CAF53EA6" + "3BB454329B7624C8917BDD64B1C0FD4CB38E8C334C701C3A" + "CDAD0657FCCFEC719B1F5C3E4E46041F388147FB4CFDB477" + "A52471F7A9A96910B855322EDB6340D8A00EF092350511E3" + "0ABEC1FFF9E3A26E7FB29F8C183023C3587E38DA0077D9B4" + "763E4E4B94B2BBC194C6651E77CAF992EEAAC0232A281BF6" + "B3A739C1226116820AE8DB5847A67CBEF9C9091B462D538C" + "D72B03746AE77F5E62292C311562A846505DC82DB854338A" + "E49F5235C95B91178CCF2DD5CACEF403EC9D1810C6272B04" + "5B3B71F9DC6B80D63FDD4A8E9ADB1E6962A69526D43161C1" + "A41D570D7938DAD4A40E329CD0E40E65FFFFFFFFFFFFFFFF"; static final DHParameters draft_ffdhe6144 = fromSafeP(draft_ffdhe6144_p); private static final String draft_ffdhe8192_p = "FFFFFFFFFFFFFFFFADF85458A2BB4A9AAFDC5620273D3CF1" + "D8B9C583CE2D3695A9E13641146433FBCC939DCE249B3EF9" + "7D2FE363630C75D8F681B202AEC4617AD3DF1ED5D5FD6561" + "2433F51F5F066ED0856365553DED1AF3B557135E7F57C935" + "984F0C70E0E68B77E2A689DAF3EFE8721DF158A136ADE735" + "30ACCA4F483A797ABC0AB182B324FB61D108A94BB2C8E3FB" + "B96ADAB760D7F4681D4F42A3DE394DF4AE56EDE76372BB19" + "0B07A7C8EE0A6D709E02FCE1CDF7E2ECC03404CD28342F61" + "9172FE9CE98583FF8E4F1232EEF28183C3FE3B1B4C6FAD73" + "3BB5FCBC2EC22005C58EF1837D1683B2C6F34A26C1B2EFFA" + "886B4238611FCFDCDE355B3B6519035BBC34F4DEF99C0238" + "61B46FC9D6E6C9077AD91D2691F7F7EE598CB0FAC186D91C" + "AEFE130985139270B4130C93BC437944F4FD4452E2D74DD3" + "64F2E21E71F54BFF5CAE82AB9C9DF69EE86D2BC522363A0D" + "ABC521979B0DEADA1DBF9A42D5C4484E0ABCD06BFA53DDEF" + "3C1B20EE3FD59D7C25E41D2B669E1EF16E6F52C3164DF4FB" + "7930E9E4E58857B6AC7D5F42D69F6D187763CF1D55034004" + "87F55BA57E31CC7A7135C886EFB4318AED6A1E012D9E6832" + "A907600A918130C46DC778F971AD0038092999A333CB8B7A" + "1A1DB93D7140003C2A4ECEA9F98D0ACC0A8291CDCEC97DCF" + "8EC9B55A7F88A46B4DB5A851F44182E1C68A007E5E0DD902" + "0BFD64B645036C7A4E677D2C38532A3A23BA4442CAF53EA6" + "3BB454329B7624C8917BDD64B1C0FD4CB38E8C334C701C3A" + "CDAD0657FCCFEC719B1F5C3E4E46041F388147FB4CFDB477" + "A52471F7A9A96910B855322EDB6340D8A00EF092350511E3" + "0ABEC1FFF9E3A26E7FB29F8C183023C3587E38DA0077D9B4" + "763E4E4B94B2BBC194C6651E77CAF992EEAAC0232A281BF6" + "B3A739C1226116820AE8DB5847A67CBEF9C9091B462D538C" + "D72B03746AE77F5E62292C311562A846505DC82DB854338A" + "E49F5235C95B91178CCF2DD5CACEF403EC9D1810C6272B04" + "5B3B71F9DC6B80D63FDD4A8E9ADB1E6962A69526D43161C1" + "A41D570D7938DAD4A40E329CCFF46AAA36AD004CF600C838" + "1E425A31D951AE64FDB23FCEC9509D43687FEB69EDD1CC5E" + "0B8CC3BDF64B10EF86B63142A3AB8829555B2F747C932665" + "CB2C0F1CC01BD70229388839D2AF05E454504AC78B758282" + "2846C0BA35C35F5C59160CC046FD8251541FC68C9C86B022" + "BB7099876A460E7451A8A93109703FEE1C217E6C3826E52C" + "51AA691E0E423CFC99E9E31650C1217B624816CDAD9A95F9" + "D5B8019488D9C0A0A1FE3075A577E23183F81D4A3F2FA457" + "1EFC8CE0BA8A4FE8B6855DFE72B0A66EDED2FBABFBE58A30" + "FAFABE1C5D71A87E2F741EF8C1FE86FEA6BBFDE530677F0D" + "97D11D49F7A8443D0822E506A9F4614E011E2A94838FF88C" + "D68C8BB7C5C6424CFFFFFFFFFFFFFFFF"; static final DHParameters draft_ffdhe8192 = fromSafeP(draft_ffdhe8192_p); public static void addNegotiatedDHEGroupsClientExtension(Hashtable extensions, short[] dheGroups) throws IOException { extensions.put(EXT_negotiated_ff_dhe_groups, createNegotiatedDHEGroupsClientExtension(dheGroups)); } public static void addNegotiatedDHEGroupsServerExtension(Hashtable extensions, short dheGroup) throws IOException { extensions.put(EXT_negotiated_ff_dhe_groups, createNegotiatedDHEGroupsServerExtension(dheGroup)); } public static short[] getNegotiatedDHEGroupsClientExtension(Hashtable extensions) throws IOException { byte[] extensionData = TlsUtils.getExtensionData(extensions, EXT_negotiated_ff_dhe_groups); return extensionData == null ? null : readNegotiatedDHEGroupsClientExtension(extensionData); } public static short getNegotiatedDHEGroupsServerExtension(Hashtable extensions) throws IOException { byte[] extensionData = TlsUtils.getExtensionData(extensions, EXT_negotiated_ff_dhe_groups); return extensionData == null ? -1 : readNegotiatedDHEGroupsServerExtension(extensionData); } public static byte[] createNegotiatedDHEGroupsClientExtension(short[] dheGroups) throws IOException { if (dheGroups == null || dheGroups.length < 1 || dheGroups.length > 255) { throw new TlsFatalAlert(AlertDescription.internal_error); } return TlsUtils.encodeUint8ArrayWithUint8Length(dheGroups); } public static byte[] createNegotiatedDHEGroupsServerExtension(short dheGroup) throws IOException { TlsUtils.checkUint8(dheGroup); byte[] extensionData = new byte[1]; TlsUtils.writeUint8(dheGroup, extensionData, 0); return extensionData; } public static short[] readNegotiatedDHEGroupsClientExtension(byte[] extensionData) throws IOException { if (extensionData == null) { throw new IllegalArgumentException("'extensionData' cannot be null"); } ByteArrayInputStream buf = new ByteArrayInputStream(extensionData); short length = TlsUtils.readUint8(buf); if (length < 1) { throw new TlsFatalAlert(AlertDescription.decode_error); } short[] dheGroups = TlsUtils.readUint8Array(length, buf); TlsProtocol.assertEmpty(buf); return dheGroups; } public static short readNegotiatedDHEGroupsServerExtension(byte[] extensionData) throws IOException { if (extensionData == null) { throw new IllegalArgumentException("'extensionData' cannot be null"); } if (extensionData.length != 1) { throw new TlsFatalAlert(AlertDescription.decode_error); } return TlsUtils.readUint8(extensionData, 0); } public static DHParameters getParametersForDHEGroup(short dheGroup) { switch (dheGroup) { case FiniteFieldDHEGroup.ffdhe2432: return draft_ffdhe2432; case FiniteFieldDHEGroup.ffdhe3072: return draft_ffdhe3072; case FiniteFieldDHEGroup.ffdhe4096: return draft_ffdhe4096; case FiniteFieldDHEGroup.ffdhe6144: return draft_ffdhe6144; case FiniteFieldDHEGroup.ffdhe8192: return draft_ffdhe8192; default: return null; } } public static boolean containsDHECipherSuites(int[] cipherSuites) { for (int i = 0; i < cipherSuites.length; ++i) { if (isDHECipherSuite(cipherSuites[i])) { return true; } } return false; } public static boolean isDHECipherSuite(int cipherSuite) { switch (cipherSuite) { /* * RFC 2246 */ case CipherSuite.TLS_DHE_DSS_EXPORT_WITH_DES40_CBC_SHA: case CipherSuite.TLS_DHE_DSS_WITH_DES_CBC_SHA: case CipherSuite.TLS_DHE_DSS_WITH_3DES_EDE_CBC_SHA: case CipherSuite.TLS_DHE_RSA_EXPORT_WITH_DES40_CBC_SHA: case CipherSuite.TLS_DHE_RSA_WITH_DES_CBC_SHA: case CipherSuite.TLS_DHE_RSA_WITH_3DES_EDE_CBC_SHA: /* * RFC 3268 */ case CipherSuite.TLS_DHE_DSS_WITH_AES_128_CBC_SHA: case CipherSuite.TLS_DHE_RSA_WITH_AES_128_CBC_SHA: case CipherSuite.TLS_DHE_DSS_WITH_AES_256_CBC_SHA: case CipherSuite.TLS_DHE_RSA_WITH_AES_256_CBC_SHA: /* * RFC 5932 */ case CipherSuite.TLS_DHE_DSS_WITH_CAMELLIA_128_CBC_SHA: case CipherSuite.TLS_DHE_RSA_WITH_CAMELLIA_128_CBC_SHA: case CipherSuite.TLS_DHE_DSS_WITH_CAMELLIA_256_CBC_SHA: case CipherSuite.TLS_DHE_RSA_WITH_CAMELLIA_256_CBC_SHA: case CipherSuite.TLS_DHE_DSS_WITH_CAMELLIA_128_CBC_SHA256: case CipherSuite.TLS_DHE_RSA_WITH_CAMELLIA_128_CBC_SHA256: case CipherSuite.TLS_DHE_DSS_WITH_CAMELLIA_256_CBC_SHA256: case CipherSuite.TLS_DHE_RSA_WITH_CAMELLIA_256_CBC_SHA256: /* * RFC 4162 */ case CipherSuite.TLS_DHE_DSS_WITH_SEED_CBC_SHA: case CipherSuite.TLS_DHE_RSA_WITH_SEED_CBC_SHA: /* * RFC 4279 */ case CipherSuite.TLS_DHE_PSK_WITH_RC4_128_SHA: case CipherSuite.TLS_DHE_PSK_WITH_3DES_EDE_CBC_SHA: case CipherSuite.TLS_DHE_PSK_WITH_AES_128_CBC_SHA: case CipherSuite.TLS_DHE_PSK_WITH_AES_256_CBC_SHA: /* * RFC 4785 */ case CipherSuite.TLS_DHE_PSK_WITH_NULL_SHA: /* * RFC 5246 */ case CipherSuite.TLS_DHE_DSS_WITH_AES_128_CBC_SHA256: case CipherSuite.TLS_DHE_RSA_WITH_AES_128_CBC_SHA256: case CipherSuite.TLS_DHE_DSS_WITH_AES_256_CBC_SHA256: case CipherSuite.TLS_DHE_RSA_WITH_AES_256_CBC_SHA256: /* * RFC 5288 */ case CipherSuite.TLS_DHE_RSA_WITH_AES_128_GCM_SHA256: case CipherSuite.TLS_DHE_RSA_WITH_AES_256_GCM_SHA384: case CipherSuite.TLS_DHE_DSS_WITH_AES_128_GCM_SHA256: case CipherSuite.TLS_DHE_DSS_WITH_AES_256_GCM_SHA384: /* * RFC 5487 */ case CipherSuite.TLS_DHE_PSK_WITH_AES_128_GCM_SHA256: case CipherSuite.TLS_DHE_PSK_WITH_AES_256_GCM_SHA384: case CipherSuite.TLS_DHE_PSK_WITH_AES_128_CBC_SHA256: case CipherSuite.TLS_DHE_PSK_WITH_AES_256_CBC_SHA384: case CipherSuite.TLS_DHE_PSK_WITH_NULL_SHA256: case CipherSuite.TLS_DHE_PSK_WITH_NULL_SHA384: /* * RFC 6367 */ case CipherSuite.TLS_DHE_RSA_WITH_CAMELLIA_128_GCM_SHA256: case CipherSuite.TLS_DHE_RSA_WITH_CAMELLIA_256_GCM_SHA384: case CipherSuite.TLS_DHE_DSS_WITH_CAMELLIA_128_GCM_SHA256: case CipherSuite.TLS_DHE_DSS_WITH_CAMELLIA_256_GCM_SHA384: case CipherSuite.TLS_DHE_PSK_WITH_CAMELLIA_128_GCM_SHA256: case CipherSuite.TLS_DHE_PSK_WITH_CAMELLIA_256_GCM_SHA384: case CipherSuite.TLS_DHE_PSK_WITH_CAMELLIA_128_CBC_SHA256: case CipherSuite.TLS_DHE_PSK_WITH_CAMELLIA_256_CBC_SHA384: /* * RFC 6655 */ case CipherSuite.TLS_DHE_RSA_WITH_AES_128_CCM: case CipherSuite.TLS_DHE_RSA_WITH_AES_256_CCM: case CipherSuite.TLS_DHE_RSA_WITH_AES_128_CCM_8: case CipherSuite.TLS_DHE_RSA_WITH_AES_256_CCM_8: case CipherSuite.TLS_DHE_PSK_WITH_AES_128_CCM: case CipherSuite.TLS_DHE_PSK_WITH_AES_256_CCM: case CipherSuite.TLS_PSK_DHE_WITH_AES_128_CCM_8: case CipherSuite.TLS_PSK_DHE_WITH_AES_256_CCM_8: /* * draft-ietf-tls-chacha20-poly1305-04 */ case CipherSuite.DRAFT_TLS_DHE_PSK_WITH_CHACHA20_POLY1305_SHA256: case CipherSuite.DRAFT_TLS_DHE_RSA_WITH_CHACHA20_POLY1305_SHA256: /* * draft-zauner-tls-aes-ocb-04 */ case CipherSuite.DRAFT_TLS_DHE_RSA_WITH_AES_128_OCB: case CipherSuite.DRAFT_TLS_DHE_RSA_WITH_AES_256_OCB: case CipherSuite.DRAFT_TLS_DHE_PSK_WITH_AES_128_OCB: case CipherSuite.DRAFT_TLS_DHE_PSK_WITH_AES_256_OCB: return true; default: return false; } } public static boolean areCompatibleParameters(DHParameters a, DHParameters b) { return a.getP().equals(b.getP()) && a.getG().equals(b.getG()) && (a.getQ() == null || b.getQ() == null || a.getQ().equals(b.getQ())); } public static byte[] calculateDHBasicAgreement(DHPublicKeyParameters publicKey, DHPrivateKeyParameters privateKey) { DHBasicAgreement basicAgreement = new DHBasicAgreement(); basicAgreement.init(privateKey); BigInteger agreementValue = basicAgreement.calculateAgreement(publicKey); /* * RFC 5246 8.1.2. Leading bytes of Z that contain all zero bits are stripped before it is * used as the pre_master_secret. */ return BigIntegers.asUnsignedByteArray(agreementValue); } public static AsymmetricCipherKeyPair generateDHKeyPair(SecureRandom random, DHParameters dhParams) { DHBasicKeyPairGenerator dhGen = new DHBasicKeyPairGenerator(); dhGen.init(new DHKeyGenerationParameters(random, dhParams)); return dhGen.generateKeyPair(); } public static DHPrivateKeyParameters generateEphemeralClientKeyExchange(SecureRandom random, DHParameters dhParams, OutputStream output) throws IOException { AsymmetricCipherKeyPair kp = generateDHKeyPair(random, dhParams); DHPublicKeyParameters dhPublic = (DHPublicKeyParameters) kp.getPublic(); writeDHParameter(dhPublic.getY(), output); return (DHPrivateKeyParameters) kp.getPrivate(); } public static DHPrivateKeyParameters generateEphemeralServerKeyExchange(SecureRandom random, DHParameters dhParams, OutputStream output) throws IOException { AsymmetricCipherKeyPair kp = generateDHKeyPair(random, dhParams); DHPublicKeyParameters dhPublic = (DHPublicKeyParameters)kp.getPublic(); new ServerDHParams(dhPublic).encode(output); return (DHPrivateKeyParameters)kp.getPrivate(); } public static DHParameters validateDHParameters(DHParameters params) throws IOException { BigInteger p = params.getP(); BigInteger g = params.getG(); if (!p.isProbablePrime(2)) { throw new TlsFatalAlert(AlertDescription.illegal_parameter); } if (g.compareTo(TWO) < 0 || g.compareTo(p.subtract(TWO)) > 0) { throw new TlsFatalAlert(AlertDescription.illegal_parameter); } return params; } public static DHPublicKeyParameters validateDHPublicKey(DHPublicKeyParameters key) throws IOException { DHParameters params = validateDHParameters(key.getParameters()); BigInteger Y = key.getY(); if (Y.compareTo(TWO) < 0 || Y.compareTo(params.getP().subtract(TWO)) > 0) { throw new TlsFatalAlert(AlertDescription.illegal_parameter); } // TODO See RFC 2631 for more discussion of Diffie-Hellman validation return key; } public static BigInteger readDHParameter(InputStream input) throws IOException { return new BigInteger(1, TlsUtils.readOpaque16(input)); } public static void writeDHParameter(BigInteger x, OutputStream output) throws IOException { TlsUtils.writeOpaque16(BigIntegers.asUnsignedByteArray(x), output); } }