/**
* <b>This Java Class consists the server side for the wondeful JavaScript library 'sha1.js'. I wrote it because I basically needed
* some cheap client/server login authentication by the usual key/data system. Besides, I got the creeps watching the password
* posted unencrypted via http requests. This class makes sure that if your client is using the 'sha1.js' to encrypt the password
* with a key sent by the server, you can always repeat the encrypting on the server side (using the same key) and compare the
* encrypted strings. Since anyone who is trapping the http requests can actually send you the same encrypted string, I suggest
* you use the client's IP address as the base for the key generation. Since IP address spoofing is not a problem, this authentication
* method is not a very secured solution. If you need a full proof solution use ssl. However, this one, sure beats nothing.
* Feel free to do with it whatever you want</b>
* <p><b>This Class is an Abstract Class, to make sure you do not create any new instances of it. It does not throw any exceptions and
* the code is much more 'C' like than pure object oriented. There are no implemented interfaces and no inheritance in use. In fact, it
* is written as close as possible to the original JavaScript code. I did not test tweaking the instance variables but if you do change
* them, make sure to apply the same change in the 'sha1.js' library or you won't get the same encrypted strings.
* You can call each one of the 6 work methods by using something like: SHA1.hex_hmac_sha1("key", "data");
* They are the only public methods. All are public and static. You have no reason to call the private ones anyway.</p></b>
* <p>The 'sha1.js' is a JavaScript implementation of the Secure Hash Algorithm, SHA-1, as defined in FIPS PUB 180-1.
* JavaScript Version 2.1 Copyright Paul Johnston 2000 - 2002. Other contributors to JavaScript version: Greg Holt,
* Andrew Kepert, Ydnar, Lostinet Distributed under the BSD License</p>
* <p>See <a Array object.
* Creation date: (3/27/2004 6:05:10 PM)
* author T.N.Silverman
* version 1.0.0
* return int[]
* param str java.lang.String
*/
private static int[] concat(int[] oldbin, int[] newbin) {
int[] retval = new int[oldbin.length + newbin.length];
for (int i = 0; i < (oldbin.length + newbin.length); i++) {
if (i < oldbin.length)
retval[i] = oldbin[i];
else
retval[i] = newbin[i - oldbin.length];
}
return retval;
}
/**
* Calculate the HMAC-SHA1 of a key and some data
* Creation date: (3/26/2004 1:05:01 PM)
* author T.N.Silverman
* version 1.0.0
* return int
* param x java.lang.String[]
* param len int
*/
private static int[] core_hmac_sha1(String key, String data) {
key = (key == null) ? "" : key;
data = (data == null) ? "" : data;
int[] bkey = complete216(str2binb(key));
if (bkey.length > 16)
bkey = core_sha1(bkey, key.length() * chrsz);
int[] ipad = new int[16];
int[] opad = new int[16];
for (int i = 0; i < 16; ipad[i] = 0, opad[i] = 0, i++);
for (int i = 0; i < 16; i++) {
ipad[i] = bkey[i] ^ 0x36363636;
opad[i] = bkey[i] ^ 0x5C5C5C5C;
}
int[] hash =
core_sha1(concat(ipad, str2binb(data)), 512 + data.length() * chrsz);
return core_sha1(concat(opad, hash), 512 + 160);
}
/**
* Calculate the SHA-1 of an array of big-endian words, and a bit length
* Creation date: (3/26/2004 1:05:01 PM)
* author T.N.Silverman
* version 1.0.0
* return int
* param x java.lang.String[]
* param len int
*/
private static int[] core_sha1(int[] x, int len) {
/* append padding */
int size = (len >> 5);
x = strechBinArray(x, size);
x[len >> 5] |= 0x80 << (24 - len % 32);
size = ((len + 64 >> 9) << 4) + 15;
x = strechBinArray(x, size);
x[((len + 64 >> 9) << 4) + 15] = len;
int[] w = new int[80];
int a = 1732584193;
int b = -271733879;
int c = -1732584194;
int d = 271733878;
int e = -1009589776;
for (int i = 0; i < x.length; i += 16) {
int olda = a;
int oldb = b;
int oldc = c;
int oldd = d;
int olde = e;
for (int j = 0; j < 80; j++) {
if (j < 16)
w[j] = x[i + j];
else
w[j] = rol(w[j - 3] ^ w[j - 8] ^ w[j - 14] ^ w[j - 16], 1);
int t =
safe_add(
safe_add(rol(a, 5), sha1_ft(j, b, c, d)),
safe_add(safe_add(e, w[j]), sha1_kt(j)));
e = d;
d = c;
c = rol(b, 30);
b = a;
a = t;
}
a = safe_add(a, olda);
b = safe_add(b, oldb);
c = safe_add(c, oldc);
d = safe_add(d, oldd);
e = safe_add(e, olde);
}
int[] retval = new int[5];
retval[0] = a;
retval[1] = b;
retval[2] = c;
retval[3] = d;
retval[4] = e;
return retval;
}
/**
* Just a test function to output the results of the 6 working funcions to the standard out.
* The two Strings used as parameters are null. Feel free to test with different values.
* Creation date:(3/27/20046:05:10PM)
* author T.N.Silverman
* version 1.0.0
* return java.lang.String
*/
private static void doTest() {
String key="key";
String data="data";
System.out.println("hex_sha1(" + data + ")=" + hex_sha1(data));
System.out.println("b64_sha1(" + data + ")=" + b64_sha1(data));
System.out.println("str_sha1(" + data + ")=" + str_sha1(data));
System.out.println("hex_hmac_sha1(" + key + "," + data + ")=" + hex_hmac_sha1(key, data));
System.out.println("b64_hmac_sha1(" + key + "," + data + ")=" + b64_hmac_sha1(key, data));
System.out.println("str_hmac_sha1(" + key + "," + data + ")=" + str_hmac_sha1(key, data));
}
/**
* This is one of the functions you'll usually want to call
* It take a string arguments and returns either hex or base-64 encoded strings
* Creation date: (3/27/2004 6:05:10 PM)
* author T.N.Silverman
* version 1.0.0
* return java.lang.String
* param key java.lang.String
* param data java.lang.String
*/
public static String hex_hmac_sha1(String key, String data) {
return binb2hex(core_hmac_sha1(key, data));
}
/**
* This is one of the functions you'll usually want to call
* It take a string argument and returns either hex or base-64 encoded strings
* Creation date: (3/27/2004 6:05:10 PM)
* author T.N.Silverman
* version 1.0.0
* return java.lang.String
* param s java.lang.String
*/
public static String hex_sha1(String s) {
s = (s == null) ? "" : s;
return binb2hex(core_sha1(str2binb(s), s.length() * chrsz));
}
/**
* Bitwise rotate a 32-bit number to the left. * Creation date: (3/26/2004 1:05:01 PM)
* Creation date: (3/27/2004 6:05:10 PM)
* author T.N.Silverman
* version 1.0.0
* return int
* param num int
* param cnt int
*/
private static int rol(int num, int cnt) {
return (num << cnt) | (num >>> (32 - cnt));
}
/**
* Add ints, wrapping at 2^32. This uses 16-bit operations internally
* to work around bugs in some JS interpreters. The original function
* is part of the sha1.js library. It's here for compatibility.
* Creation date: (3/26/2004 1:05:01 PM)
* author T.N.Silverman
* version 1.0.0
* return int
* param num int
* param cnt int
*/
private static int safe_add(int x, int y) {
int lsw = (int) (x & 0xFFFF) + (int) (y & 0xFFFF);
int msw = (x >> 16) + (y >> 16) + (lsw >> 16);
return (msw << 16) | (lsw & 0xFFFF);
}
/**
* Perform the appropriate triplet combination function for the current
* Creation date: (3/26/2004 1:05:01 PM)
* author T.N.Silverman
* version 1.0.0
* return int
* param t int
* param b int
* param c int
* param d int
*/
private static int sha1_ft(int t, int b, int c, int d) {
if (t < 20)
return (b & c) | ((~b) & d);
if (t < 40)
return b ^ c ^ d;
if (t < 60)
return (b & c) | (b & d) | (c & d);
return b ^ c ^ d;
}
/**
* Determine the appropriate additive constant for the current iteration
* Creation date: (3/26/2004 1:05:01 PM)
* author T.N.Silverman
* version 1.0.0
* return int
* param t int
*/
private static int sha1_kt(int t) {
return (t < 20)
? 1518500249
: (t < 40)
? 1859775393
: (t < 60)
? -1894007588
: -899497514;
}
/**
* This is a boolean returnig test function that exists in the sha1.js library.
* If it returns 'false' something is wrong.
* Creation date: (3/26/2004 1:05:01 PM)
* author T.N.Silverman
* version 1.0.0
* return java.lang.String
* param s java.lang.String
*/
private static boolean sha1_vm_test() {
return hexcase ? hex_sha1("abc").equals("A9993E364706816ABA3E25717850C26C9CD0D89D") : hex_sha1("abc").equals("a9993e364706816aba3e25717850c26c9cd0d89d");
}
/**
* This is one of the functions you'll usually want to call
* It take a string arguments and returns either hex or base-64 encoded strings
* Creation date: (3/26/2004 1:05:01 PM)
* author T.N.Silverman
* version 1.0.0
* return java.lang.String
* param key java.lang.String
* param data java.lang.String
*/
public static String str_hmac_sha1(String key, String data) {
return binb2str(core_hmac_sha1(key, data));
}
/**
* This is one of the functions you'll usually want to call
* It take a string argument and returns either hex or base-64 encoded strings
* Creation date: (3/26/2004 1:05:01 PM)
* author T.N.Silverman
* version 1.0.0
* return java.lang.String
* param s java.lang.String
*/
public static String str_sha1(String s) {
s = (s == null) ? "" : s;
return binb2str(core_sha1(str2binb(s), s.length() * chrsz));
}
/**
* Convert an 8-bit or 16-bit string to an array of big-endian words
* In 8-bit function, characters >255 have their hi-byte silently ignored.
* Creation date: (3/26/2004 1:05:01 PM)
* author T.N.Silverman
* version 1.0.0
* return int[]
* param str java.lang.String
*/
private static int[] str2binb(String str) {
str = (str==null) ? "" : str;
int[] tmp = new int[str.length() * chrsz];
int mask = (1 << chrsz) - 1;
for(int i = 0; i < str.length() * chrsz; i += chrsz)
tmp[i>>5] |= ( (int)(str.charAt(i / chrsz)) & mask) << (24 - i%32);

int len = 0;
for (int i=0;i<tmp.length&&tmp[i]!=0;i++,len++);
int[] bin = new int[len];
for (int i=0;i<len;i++)
bin[i] = tmp[i];
return bin;
}
/**
* increase an int array to a desired sized + 1 while keeping the old values.
* Creation date: (3/26/2004 1:05:01 PM)
* author T.N.Silverman
* version 1.0.0
* return int[]
* param str java.lang.String
*/
private static int[] strechBinArray(int[] oldbin, int size) {
int currlen = oldbin.length;
if (currlen >= size + 1)
return oldbin;
int[] newbin = new int[size + 1];
for (int i = 0; i < size; newbin[i] = 0, i++);
for (int i = 0; i < currlen; i++)
newbin[i] = oldbin[i];
return newbin;
}
}