/src/com/trilead/ssh2/crypto/cipher/BlockCipherFactory.java

https://code.google.com/p/sshtunnel/ · Java · 109 lines · 86 code · 15 blank · 8 comment · 7 complexity · 03ca6f38e915e554e56440ffe8319c57 MD5 · raw file 

    

  1. package com.trilead.ssh2.crypto.cipher;

    2. 

  2. 

    3. 

  3. import java.util.Vector;

    4. 

  4. 

    5. 

  5. /**

    6. 

  6.  * BlockCipherFactory.

    7. 

  7.  * 

    8. 

  8.  * @author Christian Plattner, plattner@trilead.com

    9. 

  9.  * @version $Id: BlockCipherFactory.java,v 1.2 2008/04/01 12:38:09 cplattne Exp

    10. 

  10.  *          $

    11. 

  11.  */

    12. 

  12. public class BlockCipherFactory {

    13. 

  13. 	static class CipherEntry {

    14. 

  14. 		String type;

    15. 

  15. 		int blocksize;

    16. 

  16. 		int keysize;

    17. 

  17. 		String cipherClass;

    18. 

  18. 

    19. 

  19. 		public CipherEntry(String type, int blockSize, int keySize,

    20. 

  20. 				String cipherClass) {

    21. 

  21. 			this.type = type;

    22. 

  22. 			this.blocksize = blockSize;

    23. 

  23. 			this.keysize = keySize;

    24. 

  24. 			this.cipherClass = cipherClass;

    25. 

  25. 		}

    26. 

  26. 	}

    27. 

  27. 

    28. 

  28. 	static Vector<CipherEntry> ciphers = new Vector<CipherEntry>();

    29. 

  29. 

    30. 

  30. 	static {

    31. 

  31. 		/* Higher Priority First */

    32. 

  32. 

    33. 

  33. 		ciphers.addElement(new CipherEntry("aes256-cbc", 16, 32,

    34. 

  34. 				"com.trilead.ssh2.crypto.cipher.AES"));

    35. 

  35. 		ciphers.addElement(new CipherEntry("aes192-cbc", 16, 24,

    36. 

  36. 				"com.trilead.ssh2.crypto.cipher.AES"));

    37. 

  37. 		ciphers.addElement(new CipherEntry("aes128-cbc", 16, 16,

    38. 

  38. 				"com.trilead.ssh2.crypto.cipher.AES"));

    39. 

  39. 		ciphers.addElement(new CipherEntry("blowfish-cbc", 8, 16,

    40. 

  40. 				"com.trilead.ssh2.crypto.cipher.BlowFish"));

    41. 

  41. 		

    42. 

  42. 		ciphers.addElement(new CipherEntry("aes256-ctr", 16, 32,

    43. 

  43. 				"com.trilead.ssh2.crypto.cipher.AES"));

    44. 

  44. 		ciphers.addElement(new CipherEntry("aes192-ctr", 16, 24,

    45. 

  45. 				"com.trilead.ssh2.crypto.cipher.AES"));

    46. 

  46. 		ciphers.addElement(new CipherEntry("aes128-ctr", 16, 16,

    47. 

  47. 				"com.trilead.ssh2.crypto.cipher.AES"));

    48. 

  48. 		ciphers.addElement(new CipherEntry("blowfish-ctr", 8, 16,

    49. 

  49. 				"com.trilead.ssh2.crypto.cipher.BlowFish"));

    50. 

  50. 

    51. 

  51. 		ciphers.addElement(new CipherEntry("3des-ctr", 8, 24,

    52. 

  52. 				"com.trilead.ssh2.crypto.cipher.DESede"));

    53. 

  53. 		ciphers.addElement(new CipherEntry("3des-cbc", 8, 24,

    54. 

  54. 				"com.trilead.ssh2.crypto.cipher.DESede"));

    55. 

  55. 	}

    56. 

  56. 

    57. 

  57. 	public static void checkCipherList(String[] cipherCandidates) {

    58. 

  58. 		for (int i = 0; i < cipherCandidates.length; i++)

    59. 

  59. 			getEntry(cipherCandidates[i]);

    60. 

  60. 	}

    61. 

  61. 

    62. 

  62. 	public static BlockCipher createCipher(String type, boolean encrypt,

    63. 

  63. 			byte[] key, byte[] iv) {

    64. 

  64. 		try {

    65. 

  65. 			CipherEntry ce = getEntry(type);

    66. 

  66. 			Class cc = Class.forName(ce.cipherClass);

    67. 

  67. 			BlockCipher bc = (BlockCipher) cc.newInstance();

    68. 

  68. 

    69. 

  69. 			if (type.endsWith("-cbc")) {

    70. 

  70. 				bc.init(encrypt, key);

    71. 

  71. 				return new CBCMode(bc, iv, encrypt);

    72. 

  72. 			} else if (type.endsWith("-ctr")) {

    73. 

  73. 				bc.init(true, key);

    74. 

  74. 				return new CTRMode(bc, iv, encrypt);

    75. 

  75. 			}

    76. 

  76. 			throw new IllegalArgumentException("Cannot instantiate " + type);

    77. 

  77. 		} catch (Exception e) {

    78. 

  78. 			throw new IllegalArgumentException("Cannot instantiate " + type);

    79. 

  79. 		}

    80. 

  80. 	}

    81. 

  81. 

    82. 

  82. 	public static int getBlockSize(String type) {

    83. 

  83. 		CipherEntry ce = getEntry(type);

    84. 

  84. 		return ce.blocksize;

    85. 

  85. 	}

    86. 

  86. 

    87. 

  87. 	public static String[] getDefaultCipherList() {

    88. 

  88. 		String list[] = new String[ciphers.size()];

    89. 

  89. 		for (int i = 0; i < ciphers.size(); i++) {

    90. 

  90. 			CipherEntry ce = ciphers.elementAt(i);

    91. 

  91. 			list[i] = new String(ce.type);

    92. 

  92. 		}

    93. 

  93. 		return list;

    94. 

  94. 	}

    95. 

  95. 

    96. 

  96. 	private static CipherEntry getEntry(String type) {

    97. 

  97. 		for (int i = 0; i < ciphers.size(); i++) {

    98. 

  98. 			CipherEntry ce = ciphers.elementAt(i);

    99. 

  99. 			if (ce.type.equals(type))

    100. 

  100. 				return ce;

    101. 

  101. 		}

    102. 

  102. 		throw new IllegalArgumentException("Unkown algorithm " + type);

    103. 

  103. 	}

    104. 

  104. 

    105. 

  105. 	public static int getKeySize(String type) {

    106. 

  106. 		CipherEntry ce = getEntry(type);

    107. 

  107. 		return ce.keysize;

    108. 

  108. 	}

    109. 

  109. }
    110.