Mercurial > sat_docs
comparison scripts/minifier/otr/dep/bigint.js @ 12:1596660ddf72
Add minifier script for otr.js and its dependencies
author | souliane <souliane@mailoo.org> |
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date | Wed, 03 Sep 2014 19:38:05 +0200 |
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11:4920c8da790b | 12:1596660ddf72 |
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1 ;(function (root, factory) { | |
2 | |
3 if (typeof define === 'function' && define.amd) { | |
4 define(factory.bind(root, root.crypto || root.msCrypto)) | |
5 } else if (typeof module !== 'undefined' && module.exports) { | |
6 module.exports = factory(require('crypto')) | |
7 } else { | |
8 root.BigInt = factory(root.crypto || root.msCrypto) | |
9 } | |
10 | |
11 }(this, function (crypto) { | |
12 | |
13 //////////////////////////////////////////////////////////////////////////////////////// | |
14 // Big Integer Library v. 5.5 | |
15 // Created 2000, last modified 2013 | |
16 // Leemon Baird | |
17 // www.leemon.com | |
18 // | |
19 // Version history: | |
20 // v 5.5 17 Mar 2013 | |
21 // - two lines of a form like "if (x<0) x+=n" had the "if" changed to "while" to | |
22 // handle the case when x<-n. (Thanks to James Ansell for finding that bug) | |
23 // v 5.4 3 Oct 2009 | |
24 // - added "var i" to greaterShift() so i is not global. (Thanks to Péter Szabó for finding that bug) | |
25 // | |
26 // v 5.3 21 Sep 2009 | |
27 // - added randProbPrime(k) for probable primes | |
28 // - unrolled loop in mont_ (slightly faster) | |
29 // - millerRabin now takes a bigInt parameter rather than an int | |
30 // | |
31 // v 5.2 15 Sep 2009 | |
32 // - fixed capitalization in call to int2bigInt in randBigInt | |
33 // (thanks to Emili Evripidou, Reinhold Behringer, and Samuel Macaleese for finding that bug) | |
34 // | |
35 // v 5.1 8 Oct 2007 | |
36 // - renamed inverseModInt_ to inverseModInt since it doesn't change its parameters | |
37 // - added functions GCD and randBigInt, which call GCD_ and randBigInt_ | |
38 // - fixed a bug found by Rob Visser (see comment with his name below) | |
39 // - improved comments | |
40 // | |
41 // This file is public domain. You can use it for any purpose without restriction. | |
42 // I do not guarantee that it is correct, so use it at your own risk. If you use | |
43 // it for something interesting, I'd appreciate hearing about it. If you find | |
44 // any bugs or make any improvements, I'd appreciate hearing about those too. | |
45 // It would also be nice if my name and URL were left in the comments. But none | |
46 // of that is required. | |
47 // | |
48 // This code defines a bigInt library for arbitrary-precision integers. | |
49 // A bigInt is an array of integers storing the value in chunks of bpe bits, | |
50 // little endian (buff[0] is the least significant word). | |
51 // Negative bigInts are stored two's complement. Almost all the functions treat | |
52 // bigInts as nonnegative. The few that view them as two's complement say so | |
53 // in their comments. Some functions assume their parameters have at least one | |
54 // leading zero element. Functions with an underscore at the end of the name put | |
55 // their answer into one of the arrays passed in, and have unpredictable behavior | |
56 // in case of overflow, so the caller must make sure the arrays are big enough to | |
57 // hold the answer. But the average user should never have to call any of the | |
58 // underscored functions. Each important underscored function has a wrapper function | |
59 // of the same name without the underscore that takes care of the details for you. | |
60 // For each underscored function where a parameter is modified, that same variable | |
61 // must not be used as another argument too. So, you cannot square x by doing | |
62 // multMod_(x,x,n). You must use squareMod_(x,n) instead, or do y=dup(x); multMod_(x,y,n). | |
63 // Or simply use the multMod(x,x,n) function without the underscore, where | |
64 // such issues never arise, because non-underscored functions never change | |
65 // their parameters; they always allocate new memory for the answer that is returned. | |
66 // | |
67 // These functions are designed to avoid frequent dynamic memory allocation in the inner loop. | |
68 // For most functions, if it needs a BigInt as a local variable it will actually use | |
69 // a global, and will only allocate to it only when it's not the right size. This ensures | |
70 // that when a function is called repeatedly with same-sized parameters, it only allocates | |
71 // memory on the first call. | |
72 // | |
73 // Note that for cryptographic purposes, the calls to Math.random() must | |
74 // be replaced with calls to a better pseudorandom number generator. | |
75 // | |
76 // In the following, "bigInt" means a bigInt with at least one leading zero element, | |
77 // and "integer" means a nonnegative integer less than radix. In some cases, integer | |
78 // can be negative. Negative bigInts are 2s complement. | |
79 // | |
80 // The following functions do not modify their inputs. | |
81 // Those returning a bigInt, string, or Array will dynamically allocate memory for that value. | |
82 // Those returning a boolean will return the integer 0 (false) or 1 (true). | |
83 // Those returning boolean or int will not allocate memory except possibly on the first | |
84 // time they're called with a given parameter size. | |
85 // | |
86 // bigInt add(x,y) //return (x+y) for bigInts x and y. | |
87 // bigInt addInt(x,n) //return (x+n) where x is a bigInt and n is an integer. | |
88 // string bigInt2str(x,base) //return a string form of bigInt x in a given base, with 2 <= base <= 95 | |
89 // int bitSize(x) //return how many bits long the bigInt x is, not counting leading zeros | |
90 // bigInt dup(x) //return a copy of bigInt x | |
91 // boolean equals(x,y) //is the bigInt x equal to the bigint y? | |
92 // boolean equalsInt(x,y) //is bigint x equal to integer y? | |
93 // bigInt expand(x,n) //return a copy of x with at least n elements, adding leading zeros if needed | |
94 // Array findPrimes(n) //return array of all primes less than integer n | |
95 // bigInt GCD(x,y) //return greatest common divisor of bigInts x and y (each with same number of elements). | |
96 // boolean greater(x,y) //is x>y? (x and y are nonnegative bigInts) | |
97 // boolean greaterShift(x,y,shift)//is (x <<(shift*bpe)) > y? | |
98 // bigInt int2bigInt(t,n,m) //return a bigInt equal to integer t, with at least n bits and m array elements | |
99 // bigInt inverseMod(x,n) //return (x**(-1) mod n) for bigInts x and n. If no inverse exists, it returns null | |
100 // int inverseModInt(x,n) //return x**(-1) mod n, for integers x and n. Return 0 if there is no inverse | |
101 // boolean isZero(x) //is the bigInt x equal to zero? | |
102 // boolean millerRabin(x,b) //does one round of Miller-Rabin base integer b say that bigInt x is possibly prime? (b is bigInt, 1<b<x) | |
103 // boolean millerRabinInt(x,b) //does one round of Miller-Rabin base integer b say that bigInt x is possibly prime? (b is int, 1<b<x) | |
104 // bigInt mod(x,n) //return a new bigInt equal to (x mod n) for bigInts x and n. | |
105 // int modInt(x,n) //return x mod n for bigInt x and integer n. | |
106 // bigInt mult(x,y) //return x*y for bigInts x and y. This is faster when y<x. | |
107 // bigInt multMod(x,y,n) //return (x*y mod n) for bigInts x,y,n. For greater speed, let y<x. | |
108 // boolean negative(x) //is bigInt x negative? | |
109 // bigInt powMod(x,y,n) //return (x**y mod n) where x,y,n are bigInts and ** is exponentiation. 0**0=1. Faster for odd n. | |
110 // bigInt randBigInt(n,s) //return an n-bit random BigInt (n>=1). If s=1, then the most significant of those n bits is set to 1. | |
111 // bigInt randTruePrime(k) //return a new, random, k-bit, true prime bigInt using Maurer's algorithm. | |
112 // bigInt randProbPrime(k) //return a new, random, k-bit, probable prime bigInt (probability it's composite less than 2^-80). | |
113 // bigInt str2bigInt(s,b,n,m) //return a bigInt for number represented in string s in base b with at least n bits and m array elements | |
114 // bigInt sub(x,y) //return (x-y) for bigInts x and y. Negative answers will be 2s complement | |
115 // bigInt trim(x,k) //return a copy of x with exactly k leading zero elements | |
116 // | |
117 // | |
118 // The following functions each have a non-underscored version, which most users should call instead. | |
119 // These functions each write to a single parameter, and the caller is responsible for ensuring the array | |
120 // passed in is large enough to hold the result. | |
121 // | |
122 // void addInt_(x,n) //do x=x+n where x is a bigInt and n is an integer | |
123 // void add_(x,y) //do x=x+y for bigInts x and y | |
124 // void copy_(x,y) //do x=y on bigInts x and y | |
125 // void copyInt_(x,n) //do x=n on bigInt x and integer n | |
126 // void GCD_(x,y) //set x to the greatest common divisor of bigInts x and y, (y is destroyed). (This never overflows its array). | |
127 // boolean inverseMod_(x,n) //do x=x**(-1) mod n, for bigInts x and n. Returns 1 (0) if inverse does (doesn't) exist | |
128 // void mod_(x,n) //do x=x mod n for bigInts x and n. (This never overflows its array). | |
129 // void mult_(x,y) //do x=x*y for bigInts x and y. | |
130 // void multMod_(x,y,n) //do x=x*y mod n for bigInts x,y,n. | |
131 // void powMod_(x,y,n) //do x=x**y mod n, where x,y,n are bigInts (n is odd) and ** is exponentiation. 0**0=1. | |
132 // void randBigInt_(b,n,s) //do b = an n-bit random BigInt. if s=1, then nth bit (most significant bit) is set to 1. n>=1. | |
133 // void randTruePrime_(ans,k) //do ans = a random k-bit true random prime (not just probable prime) with 1 in the msb. | |
134 // void sub_(x,y) //do x=x-y for bigInts x and y. Negative answers will be 2s complement. | |
135 // | |
136 // The following functions do NOT have a non-underscored version. | |
137 // They each write a bigInt result to one or more parameters. The caller is responsible for | |
138 // ensuring the arrays passed in are large enough to hold the results. | |
139 // | |
140 // void addShift_(x,y,ys) //do x=x+(y<<(ys*bpe)) | |
141 // void carry_(x) //do carries and borrows so each element of the bigInt x fits in bpe bits. | |
142 // void divide_(x,y,q,r) //divide x by y giving quotient q and remainder r | |
143 // int divInt_(x,n) //do x=floor(x/n) for bigInt x and integer n, and return the remainder. (This never overflows its array). | |
144 // int eGCD_(x,y,d,a,b) //sets a,b,d to positive bigInts such that d = GCD_(x,y) = a*x-b*y | |
145 // void halve_(x) //do x=floor(|x|/2)*sgn(x) for bigInt x in 2's complement. (This never overflows its array). | |
146 // void leftShift_(x,n) //left shift bigInt x by n bits. n<bpe. | |
147 // void linComb_(x,y,a,b) //do x=a*x+b*y for bigInts x and y and integers a and b | |
148 // void linCombShift_(x,y,b,ys) //do x=x+b*(y<<(ys*bpe)) for bigInts x and y, and integers b and ys | |
149 // void mont_(x,y,n,np) //Montgomery multiplication (see comments where the function is defined) | |
150 // void multInt_(x,n) //do x=x*n where x is a bigInt and n is an integer. | |
151 // void rightShift_(x,n) //right shift bigInt x by n bits. (This never overflows its array). | |
152 // void squareMod_(x,n) //do x=x*x mod n for bigInts x,n | |
153 // void subShift_(x,y,ys) //do x=x-(y<<(ys*bpe)). Negative answers will be 2s complement. | |
154 // | |
155 // The following functions are based on algorithms from the _Handbook of Applied Cryptography_ | |
156 // powMod_() = algorithm 14.94, Montgomery exponentiation | |
157 // eGCD_,inverseMod_() = algorithm 14.61, Binary extended GCD_ | |
158 // GCD_() = algorothm 14.57, Lehmer's algorithm | |
159 // mont_() = algorithm 14.36, Montgomery multiplication | |
160 // divide_() = algorithm 14.20 Multiple-precision division | |
161 // squareMod_() = algorithm 14.16 Multiple-precision squaring | |
162 // randTruePrime_() = algorithm 4.62, Maurer's algorithm | |
163 // millerRabin() = algorithm 4.24, Miller-Rabin algorithm | |
164 // | |
165 // Profiling shows: | |
166 // randTruePrime_() spends: | |
167 // 10% of its time in calls to powMod_() | |
168 // 85% of its time in calls to millerRabin() | |
169 // millerRabin() spends: | |
170 // 99% of its time in calls to powMod_() (always with a base of 2) | |
171 // powMod_() spends: | |
172 // 94% of its time in calls to mont_() (almost always with x==y) | |
173 // | |
174 // This suggests there are several ways to speed up this library slightly: | |
175 // - convert powMod_ to use a Montgomery form of k-ary window (or maybe a Montgomery form of sliding window) | |
176 // -- this should especially focus on being fast when raising 2 to a power mod n | |
177 // - convert randTruePrime_() to use a minimum r of 1/3 instead of 1/2 with the appropriate change to the test | |
178 // - tune the parameters in randTruePrime_(), including c, m, and recLimit | |
179 // - speed up the single loop in mont_() that takes 95% of the runtime, perhaps by reducing checking | |
180 // within the loop when all the parameters are the same length. | |
181 // | |
182 // There are several ideas that look like they wouldn't help much at all: | |
183 // - replacing trial division in randTruePrime_() with a sieve (that speeds up something taking almost no time anyway) | |
184 // - increase bpe from 15 to 30 (that would help if we had a 32*32->64 multiplier, but not with JavaScript's 32*32->32) | |
185 // - speeding up mont_(x,y,n,np) when x==y by doing a non-modular, non-Montgomery square | |
186 // followed by a Montgomery reduction. The intermediate answer will be twice as long as x, so that | |
187 // method would be slower. This is unfortunate because the code currently spends almost all of its time | |
188 // doing mont_(x,x,...), both for randTruePrime_() and powMod_(). A faster method for Montgomery squaring | |
189 // would have a large impact on the speed of randTruePrime_() and powMod_(). HAC has a couple of poorly-worded | |
190 // sentences that seem to imply it's faster to do a non-modular square followed by a single | |
191 // Montgomery reduction, but that's obviously wrong. | |
192 //////////////////////////////////////////////////////////////////////////////////////// | |
193 | |
194 //globals | |
195 | |
196 // The number of significant bits in the fraction of a JavaScript | |
197 // floating-point number is 52, independent of platform. | |
198 // See: https://github.com/arlolra/otr/issues/41 | |
199 | |
200 var bpe = 26; // bits stored per array element | |
201 var radix = 1 << bpe; // equals 2^bpe | |
202 var mask = radix - 1; // AND this with an array element to chop it down to bpe bits | |
203 | |
204 //the digits for converting to different bases | |
205 var digitsStr='0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz_=!@#$%^&*()[]{}|;:,.<>/?`~ \\\'\"+-'; | |
206 | |
207 var one=int2bigInt(1,1,1); //constant used in powMod_() | |
208 | |
209 //the following global variables are scratchpad memory to | |
210 //reduce dynamic memory allocation in the inner loop | |
211 var t=new Array(0); | |
212 var ss=t; //used in mult_() | |
213 var s0=t; //used in multMod_(), squareMod_() | |
214 var s1=t; //used in powMod_(), multMod_(), squareMod_() | |
215 var s2=t; //used in powMod_(), multMod_() | |
216 var s3=t; //used in powMod_() | |
217 var s4=t, s5=t; //used in mod_() | |
218 var s6=t; //used in bigInt2str() | |
219 var s7=t; //used in powMod_() | |
220 var T=t; //used in GCD_() | |
221 var sa=t; //used in mont_() | |
222 var mr_x1=t, mr_r=t, mr_a=t; //used in millerRabin() | |
223 var eg_v=t, eg_u=t, eg_A=t, eg_B=t, eg_C=t, eg_D=t; //used in eGCD_(), inverseMod_() | |
224 var md_q1=t, md_q2=t, md_q3=t, md_r=t, md_r1=t, md_r2=t, md_tt=t; //used in mod_() | |
225 | |
226 var primes=t, pows=t, s_i=t, s_i2=t, s_R=t, s_rm=t, s_q=t, s_n1=t; | |
227 var s_a=t, s_r2=t, s_n=t, s_b=t, s_d=t, s_x1=t, s_x2=t, s_aa=t; //used in randTruePrime_() | |
228 | |
229 var rpprb=t; //used in randProbPrimeRounds() (which also uses "primes") | |
230 | |
231 //////////////////////////////////////////////////////////////////////////////////////// | |
232 | |
233 | |
234 //return array of all primes less than integer n | |
235 function findPrimes(n) { | |
236 var i,s,p,ans; | |
237 s=new Array(n); | |
238 for (i=0;i<n;i++) | |
239 s[i]=0; | |
240 s[0]=2; | |
241 p=0; //first p elements of s are primes, the rest are a sieve | |
242 for(;s[p]<n;) { //s[p] is the pth prime | |
243 for(i=s[p]*s[p]; i<n; i+=s[p]) //mark multiples of s[p] | |
244 s[i]=1; | |
245 p++; | |
246 s[p]=s[p-1]+1; | |
247 for(; s[p]<n && s[s[p]]; s[p]++); //find next prime (where s[p]==0) | |
248 } | |
249 ans=new Array(p); | |
250 for(i=0;i<p;i++) | |
251 ans[i]=s[i]; | |
252 return ans; | |
253 } | |
254 | |
255 | |
256 //does a single round of Miller-Rabin base b consider x to be a possible prime? | |
257 //x is a bigInt, and b is an integer, with b<x | |
258 function millerRabinInt(x,b) { | |
259 if (mr_x1.length!=x.length) { | |
260 mr_x1=dup(x); | |
261 mr_r=dup(x); | |
262 mr_a=dup(x); | |
263 } | |
264 | |
265 copyInt_(mr_a,b); | |
266 return millerRabin(x,mr_a); | |
267 } | |
268 | |
269 //does a single round of Miller-Rabin base b consider x to be a possible prime? | |
270 //x and b are bigInts with b<x | |
271 function millerRabin(x,b) { | |
272 var i,j,k,s; | |
273 | |
274 if (mr_x1.length!=x.length) { | |
275 mr_x1=dup(x); | |
276 mr_r=dup(x); | |
277 mr_a=dup(x); | |
278 } | |
279 | |
280 copy_(mr_a,b); | |
281 copy_(mr_r,x); | |
282 copy_(mr_x1,x); | |
283 | |
284 addInt_(mr_r,-1); | |
285 addInt_(mr_x1,-1); | |
286 | |
287 //s=the highest power of two that divides mr_r | |
288 | |
289 /* | |
290 k=0; | |
291 for (i=0;i<mr_r.length;i++) | |
292 for (j=1;j<mask;j<<=1) | |
293 if (x[i] & j) { | |
294 s=(k<mr_r.length+bpe ? k : 0); | |
295 i=mr_r.length; | |
296 j=mask; | |
297 } else | |
298 k++; | |
299 */ | |
300 | |
301 /* http://www.javascripter.net/math/primes/millerrabinbug-bigint54.htm */ | |
302 if (isZero(mr_r)) return 0; | |
303 for (k=0; mr_r[k]==0; k++); | |
304 for (i=1,j=2; mr_r[k]%j==0; j*=2,i++ ); | |
305 s = k*bpe + i - 1; | |
306 /* end */ | |
307 | |
308 if (s) | |
309 rightShift_(mr_r,s); | |
310 | |
311 powMod_(mr_a,mr_r,x); | |
312 | |
313 if (!equalsInt(mr_a,1) && !equals(mr_a,mr_x1)) { | |
314 j=1; | |
315 while (j<=s-1 && !equals(mr_a,mr_x1)) { | |
316 squareMod_(mr_a,x); | |
317 if (equalsInt(mr_a,1)) { | |
318 return 0; | |
319 } | |
320 j++; | |
321 } | |
322 if (!equals(mr_a,mr_x1)) { | |
323 return 0; | |
324 } | |
325 } | |
326 return 1; | |
327 } | |
328 | |
329 //returns how many bits long the bigInt is, not counting leading zeros. | |
330 function bitSize(x) { | |
331 var j,z,w; | |
332 for (j=x.length-1; (x[j]==0) && (j>0); j--); | |
333 for (z=0,w=x[j]; w; (w>>=1),z++); | |
334 z+=bpe*j; | |
335 return z; | |
336 } | |
337 | |
338 //return a copy of x with at least n elements, adding leading zeros if needed | |
339 function expand(x,n) { | |
340 var ans=int2bigInt(0,(x.length>n ? x.length : n)*bpe,0); | |
341 copy_(ans,x); | |
342 return ans; | |
343 } | |
344 | |
345 //return a k-bit true random prime using Maurer's algorithm. | |
346 function randTruePrime(k) { | |
347 var ans=int2bigInt(0,k,0); | |
348 randTruePrime_(ans,k); | |
349 return trim(ans,1); | |
350 } | |
351 | |
352 //return a k-bit random probable prime with probability of error < 2^-80 | |
353 function randProbPrime(k) { | |
354 if (k>=600) return randProbPrimeRounds(k,2); //numbers from HAC table 4.3 | |
355 if (k>=550) return randProbPrimeRounds(k,4); | |
356 if (k>=500) return randProbPrimeRounds(k,5); | |
357 if (k>=400) return randProbPrimeRounds(k,6); | |
358 if (k>=350) return randProbPrimeRounds(k,7); | |
359 if (k>=300) return randProbPrimeRounds(k,9); | |
360 if (k>=250) return randProbPrimeRounds(k,12); //numbers from HAC table 4.4 | |
361 if (k>=200) return randProbPrimeRounds(k,15); | |
362 if (k>=150) return randProbPrimeRounds(k,18); | |
363 if (k>=100) return randProbPrimeRounds(k,27); | |
364 return randProbPrimeRounds(k,40); //number from HAC remark 4.26 (only an estimate) | |
365 } | |
366 | |
367 //return a k-bit probable random prime using n rounds of Miller Rabin (after trial division with small primes) | |
368 function randProbPrimeRounds(k,n) { | |
369 var ans, i, divisible, B; | |
370 B=30000; //B is largest prime to use in trial division | |
371 ans=int2bigInt(0,k,0); | |
372 | |
373 //optimization: try larger and smaller B to find the best limit. | |
374 | |
375 if (primes.length==0) | |
376 primes=findPrimes(30000); //check for divisibility by primes <=30000 | |
377 | |
378 if (rpprb.length!=ans.length) | |
379 rpprb=dup(ans); | |
380 | |
381 for (;;) { //keep trying random values for ans until one appears to be prime | |
382 //optimization: pick a random number times L=2*3*5*...*p, plus a | |
383 // random element of the list of all numbers in [0,L) not divisible by any prime up to p. | |
384 // This can reduce the amount of random number generation. | |
385 | |
386 randBigInt_(ans,k,0); //ans = a random odd number to check | |
387 ans[0] |= 1; | |
388 divisible=0; | |
389 | |
390 //check ans for divisibility by small primes up to B | |
391 for (i=0; (i<primes.length) && (primes[i]<=B); i++) | |
392 if (modInt(ans,primes[i])==0 && !equalsInt(ans,primes[i])) { | |
393 divisible=1; | |
394 break; | |
395 } | |
396 | |
397 //optimization: change millerRabin so the base can be bigger than the number being checked, then eliminate the while here. | |
398 | |
399 //do n rounds of Miller Rabin, with random bases less than ans | |
400 for (i=0; i<n && !divisible; i++) { | |
401 randBigInt_(rpprb,k,0); | |
402 while(!greater(ans,rpprb)) //pick a random rpprb that's < ans | |
403 randBigInt_(rpprb,k,0); | |
404 if (!millerRabin(ans,rpprb)) | |
405 divisible=1; | |
406 } | |
407 | |
408 if(!divisible) | |
409 return ans; | |
410 } | |
411 } | |
412 | |
413 //return a new bigInt equal to (x mod n) for bigInts x and n. | |
414 function mod(x,n) { | |
415 var ans=dup(x); | |
416 mod_(ans,n); | |
417 return trim(ans,1); | |
418 } | |
419 | |
420 //return (x+n) where x is a bigInt and n is an integer. | |
421 function addInt(x,n) { | |
422 var ans=expand(x,x.length+1); | |
423 addInt_(ans,n); | |
424 return trim(ans,1); | |
425 } | |
426 | |
427 //return x*y for bigInts x and y. This is faster when y<x. | |
428 function mult(x,y) { | |
429 var ans=expand(x,x.length+y.length); | |
430 mult_(ans,y); | |
431 return trim(ans,1); | |
432 } | |
433 | |
434 //return (x**y mod n) where x,y,n are bigInts and ** is exponentiation. 0**0=1. Faster for odd n. | |
435 function powMod(x,y,n) { | |
436 var ans=expand(x,n.length); | |
437 powMod_(ans,trim(y,2),trim(n,2),0); //this should work without the trim, but doesn't | |
438 return trim(ans,1); | |
439 } | |
440 | |
441 //return (x-y) for bigInts x and y. Negative answers will be 2s complement | |
442 function sub(x,y) { | |
443 var ans=expand(x,(x.length>y.length ? x.length+1 : y.length+1)); | |
444 sub_(ans,y); | |
445 return trim(ans,1); | |
446 } | |
447 | |
448 //return (x+y) for bigInts x and y. | |
449 function add(x,y) { | |
450 var ans=expand(x,(x.length>y.length ? x.length+1 : y.length+1)); | |
451 add_(ans,y); | |
452 return trim(ans,1); | |
453 } | |
454 | |
455 //return (x**(-1) mod n) for bigInts x and n. If no inverse exists, it returns null | |
456 function inverseMod(x,n) { | |
457 var ans=expand(x,n.length); | |
458 var s; | |
459 s=inverseMod_(ans,n); | |
460 return s ? trim(ans,1) : null; | |
461 } | |
462 | |
463 //return (x*y mod n) for bigInts x,y,n. For greater speed, let y<x. | |
464 function multMod(x,y,n) { | |
465 var ans=expand(x,n.length); | |
466 multMod_(ans,y,n); | |
467 return trim(ans,1); | |
468 } | |
469 | |
470 //generate a k-bit true random prime using Maurer's algorithm, | |
471 //and put it into ans. The bigInt ans must be large enough to hold it. | |
472 function randTruePrime_(ans,k) { | |
473 var c,w,m,pm,dd,j,r,B,divisible,z,zz,recSize,recLimit; | |
474 | |
475 if (primes.length==0) | |
476 primes=findPrimes(30000); //check for divisibility by primes <=30000 | |
477 | |
478 if (pows.length==0) { | |
479 pows=new Array(512); | |
480 for (j=0;j<512;j++) { | |
481 pows[j]=Math.pow(2,j/511.0-1.0); | |
482 } | |
483 } | |
484 | |
485 //c and m should be tuned for a particular machine and value of k, to maximize speed | |
486 c=0.1; //c=0.1 in HAC | |
487 m=20; //generate this k-bit number by first recursively generating a number that has between k/2 and k-m bits | |
488 recLimit=20; //stop recursion when k <=recLimit. Must have recLimit >= 2 | |
489 | |
490 if (s_i2.length!=ans.length) { | |
491 s_i2=dup(ans); | |
492 s_R =dup(ans); | |
493 s_n1=dup(ans); | |
494 s_r2=dup(ans); | |
495 s_d =dup(ans); | |
496 s_x1=dup(ans); | |
497 s_x2=dup(ans); | |
498 s_b =dup(ans); | |
499 s_n =dup(ans); | |
500 s_i =dup(ans); | |
501 s_rm=dup(ans); | |
502 s_q =dup(ans); | |
503 s_a =dup(ans); | |
504 s_aa=dup(ans); | |
505 } | |
506 | |
507 if (k <= recLimit) { //generate small random primes by trial division up to its square root | |
508 pm=(1<<((k+2)>>1))-1; //pm is binary number with all ones, just over sqrt(2^k) | |
509 copyInt_(ans,0); | |
510 for (dd=1;dd;) { | |
511 dd=0; | |
512 ans[0]= 1 | (1<<(k-1)) | randomBitInt(k); //random, k-bit, odd integer, with msb 1 | |
513 for (j=1;(j<primes.length) && ((primes[j]&pm)==primes[j]);j++) { //trial division by all primes 3...sqrt(2^k) | |
514 if (0==(ans[0]%primes[j])) { | |
515 dd=1; | |
516 break; | |
517 } | |
518 } | |
519 } | |
520 carry_(ans); | |
521 return; | |
522 } | |
523 | |
524 B=c*k*k; //try small primes up to B (or all the primes[] array if the largest is less than B). | |
525 if (k>2*m) //generate this k-bit number by first recursively generating a number that has between k/2 and k-m bits | |
526 for (r=1; k-k*r<=m; ) | |
527 r=pows[randomBitInt(9)]; //r=Math.pow(2,Math.random()-1); | |
528 else | |
529 r=0.5; | |
530 | |
531 //simulation suggests the more complex algorithm using r=.333 is only slightly faster. | |
532 | |
533 recSize=Math.floor(r*k)+1; | |
534 | |
535 randTruePrime_(s_q,recSize); | |
536 copyInt_(s_i2,0); | |
537 s_i2[Math.floor((k-2)/bpe)] |= (1<<((k-2)%bpe)); //s_i2=2^(k-2) | |
538 divide_(s_i2,s_q,s_i,s_rm); //s_i=floor((2^(k-1))/(2q)) | |
539 | |
540 z=bitSize(s_i); | |
541 | |
542 for (;;) { | |
543 for (;;) { //generate z-bit numbers until one falls in the range [0,s_i-1] | |
544 randBigInt_(s_R,z,0); | |
545 if (greater(s_i,s_R)) | |
546 break; | |
547 } //now s_R is in the range [0,s_i-1] | |
548 addInt_(s_R,1); //now s_R is in the range [1,s_i] | |
549 add_(s_R,s_i); //now s_R is in the range [s_i+1,2*s_i] | |
550 | |
551 copy_(s_n,s_q); | |
552 mult_(s_n,s_R); | |
553 multInt_(s_n,2); | |
554 addInt_(s_n,1); //s_n=2*s_R*s_q+1 | |
555 | |
556 copy_(s_r2,s_R); | |
557 multInt_(s_r2,2); //s_r2=2*s_R | |
558 | |
559 //check s_n for divisibility by small primes up to B | |
560 for (divisible=0,j=0; (j<primes.length) && (primes[j]<B); j++) | |
561 if (modInt(s_n,primes[j])==0 && !equalsInt(s_n,primes[j])) { | |
562 divisible=1; | |
563 break; | |
564 } | |
565 | |
566 if (!divisible) //if it passes small primes check, then try a single Miller-Rabin base 2 | |
567 if (!millerRabinInt(s_n,2)) //this line represents 75% of the total runtime for randTruePrime_ | |
568 divisible=1; | |
569 | |
570 if (!divisible) { //if it passes that test, continue checking s_n | |
571 addInt_(s_n,-3); | |
572 for (j=s_n.length-1;(s_n[j]==0) && (j>0); j--); //strip leading zeros | |
573 for (zz=0,w=s_n[j]; w; (w>>=1),zz++); | |
574 zz+=bpe*j; //zz=number of bits in s_n, ignoring leading zeros | |
575 for (;;) { //generate z-bit numbers until one falls in the range [0,s_n-1] | |
576 randBigInt_(s_a,zz,0); | |
577 if (greater(s_n,s_a)) | |
578 break; | |
579 } //now s_a is in the range [0,s_n-1] | |
580 addInt_(s_n,3); //now s_a is in the range [0,s_n-4] | |
581 addInt_(s_a,2); //now s_a is in the range [2,s_n-2] | |
582 copy_(s_b,s_a); | |
583 copy_(s_n1,s_n); | |
584 addInt_(s_n1,-1); | |
585 powMod_(s_b,s_n1,s_n); //s_b=s_a^(s_n-1) modulo s_n | |
586 addInt_(s_b,-1); | |
587 if (isZero(s_b)) { | |
588 copy_(s_b,s_a); | |
589 powMod_(s_b,s_r2,s_n); | |
590 addInt_(s_b,-1); | |
591 copy_(s_aa,s_n); | |
592 copy_(s_d,s_b); | |
593 GCD_(s_d,s_n); //if s_b and s_n are relatively prime, then s_n is a prime | |
594 if (equalsInt(s_d,1)) { | |
595 copy_(ans,s_aa); | |
596 return; //if we've made it this far, then s_n is absolutely guaranteed to be prime | |
597 } | |
598 } | |
599 } | |
600 } | |
601 } | |
602 | |
603 //Return an n-bit random BigInt (n>=1). If s=1, then the most significant of those n bits is set to 1. | |
604 function randBigInt(n,s) { | |
605 var a,b; | |
606 a=Math.floor((n-1)/bpe)+2; //# array elements to hold the BigInt with a leading 0 element | |
607 b=int2bigInt(0,0,a); | |
608 randBigInt_(b,n,s); | |
609 return b; | |
610 } | |
611 | |
612 //Set b to an n-bit random BigInt. If s=1, then the most significant of those n bits is set to 1. | |
613 //Array b must be big enough to hold the result. Must have n>=1 | |
614 function randBigInt_(b,n,s) { | |
615 var i,a; | |
616 for (i=0;i<b.length;i++) | |
617 b[i]=0; | |
618 a=Math.floor((n-1)/bpe)+1; //# array elements to hold the BigInt | |
619 for (i=0;i<a;i++) { | |
620 b[i]=randomBitInt(bpe); | |
621 } | |
622 b[a-1] &= (2<<((n-1)%bpe))-1; | |
623 if (s==1) | |
624 b[a-1] |= (1<<((n-1)%bpe)); | |
625 } | |
626 | |
627 //Return the greatest common divisor of bigInts x and y (each with same number of elements). | |
628 function GCD(x,y) { | |
629 var xc,yc; | |
630 xc=dup(x); | |
631 yc=dup(y); | |
632 GCD_(xc,yc); | |
633 return xc; | |
634 } | |
635 | |
636 //set x to the greatest common divisor of bigInts x and y (each with same number of elements). | |
637 //y is destroyed. | |
638 function GCD_(x,y) { | |
639 var i,xp,yp,A,B,C,D,q,sing,qp; | |
640 if (T.length!=x.length) | |
641 T=dup(x); | |
642 | |
643 sing=1; | |
644 while (sing) { //while y has nonzero elements other than y[0] | |
645 sing=0; | |
646 for (i=1;i<y.length;i++) //check if y has nonzero elements other than 0 | |
647 if (y[i]) { | |
648 sing=1; | |
649 break; | |
650 } | |
651 if (!sing) break; //quit when y all zero elements except possibly y[0] | |
652 | |
653 for (i=x.length;!x[i] && i>=0;i--); //find most significant element of x | |
654 xp=x[i]; | |
655 yp=y[i]; | |
656 A=1; B=0; C=0; D=1; | |
657 while ((yp+C) && (yp+D)) { | |
658 q =Math.floor((xp+A)/(yp+C)); | |
659 qp=Math.floor((xp+B)/(yp+D)); | |
660 if (q!=qp) | |
661 break; | |
662 t= A-q*C; A=C; C=t; // do (A,B,xp, C,D,yp) = (C,D,yp, A,B,xp) - q*(0,0,0, C,D,yp) | |
663 t= B-q*D; B=D; D=t; | |
664 t=xp-q*yp; xp=yp; yp=t; | |
665 } | |
666 if (B) { | |
667 copy_(T,x); | |
668 linComb_(x,y,A,B); //x=A*x+B*y | |
669 linComb_(y,T,D,C); //y=D*y+C*T | |
670 } else { | |
671 mod_(x,y); | |
672 copy_(T,x); | |
673 copy_(x,y); | |
674 copy_(y,T); | |
675 } | |
676 } | |
677 if (y[0]==0) | |
678 return; | |
679 t=modInt(x,y[0]); | |
680 copyInt_(x,y[0]); | |
681 y[0]=t; | |
682 while (y[0]) { | |
683 x[0]%=y[0]; | |
684 t=x[0]; x[0]=y[0]; y[0]=t; | |
685 } | |
686 } | |
687 | |
688 //do x=x**(-1) mod n, for bigInts x and n. | |
689 //If no inverse exists, it sets x to zero and returns 0, else it returns 1. | |
690 //The x array must be at least as large as the n array. | |
691 function inverseMod_(x,n) { | |
692 var k=1+2*Math.max(x.length,n.length); | |
693 | |
694 if(!(x[0]&1) && !(n[0]&1)) { //if both inputs are even, then inverse doesn't exist | |
695 copyInt_(x,0); | |
696 return 0; | |
697 } | |
698 | |
699 if (eg_u.length!=k) { | |
700 eg_u=new Array(k); | |
701 eg_v=new Array(k); | |
702 eg_A=new Array(k); | |
703 eg_B=new Array(k); | |
704 eg_C=new Array(k); | |
705 eg_D=new Array(k); | |
706 } | |
707 | |
708 copy_(eg_u,x); | |
709 copy_(eg_v,n); | |
710 copyInt_(eg_A,1); | |
711 copyInt_(eg_B,0); | |
712 copyInt_(eg_C,0); | |
713 copyInt_(eg_D,1); | |
714 for (;;) { | |
715 while(!(eg_u[0]&1)) { //while eg_u is even | |
716 halve_(eg_u); | |
717 if (!(eg_A[0]&1) && !(eg_B[0]&1)) { //if eg_A==eg_B==0 mod 2 | |
718 halve_(eg_A); | |
719 halve_(eg_B); | |
720 } else { | |
721 add_(eg_A,n); halve_(eg_A); | |
722 sub_(eg_B,x); halve_(eg_B); | |
723 } | |
724 } | |
725 | |
726 while (!(eg_v[0]&1)) { //while eg_v is even | |
727 halve_(eg_v); | |
728 if (!(eg_C[0]&1) && !(eg_D[0]&1)) { //if eg_C==eg_D==0 mod 2 | |
729 halve_(eg_C); | |
730 halve_(eg_D); | |
731 } else { | |
732 add_(eg_C,n); halve_(eg_C); | |
733 sub_(eg_D,x); halve_(eg_D); | |
734 } | |
735 } | |
736 | |
737 if (!greater(eg_v,eg_u)) { //eg_v <= eg_u | |
738 sub_(eg_u,eg_v); | |
739 sub_(eg_A,eg_C); | |
740 sub_(eg_B,eg_D); | |
741 } else { //eg_v > eg_u | |
742 sub_(eg_v,eg_u); | |
743 sub_(eg_C,eg_A); | |
744 sub_(eg_D,eg_B); | |
745 } | |
746 | |
747 if (equalsInt(eg_u,0)) { | |
748 while (negative(eg_C)) //make sure answer is nonnegative | |
749 add_(eg_C,n); | |
750 copy_(x,eg_C); | |
751 | |
752 if (!equalsInt(eg_v,1)) { //if GCD_(x,n)!=1, then there is no inverse | |
753 copyInt_(x,0); | |
754 return 0; | |
755 } | |
756 return 1; | |
757 } | |
758 } | |
759 } | |
760 | |
761 //return x**(-1) mod n, for integers x and n. Return 0 if there is no inverse | |
762 function inverseModInt(x,n) { | |
763 var a=1,b=0,t; | |
764 for (;;) { | |
765 if (x==1) return a; | |
766 if (x==0) return 0; | |
767 b-=a*Math.floor(n/x); | |
768 n%=x; | |
769 | |
770 if (n==1) return b; //to avoid negatives, change this b to n-b, and each -= to += | |
771 if (n==0) return 0; | |
772 a-=b*Math.floor(x/n); | |
773 x%=n; | |
774 } | |
775 } | |
776 | |
777 //this deprecated function is for backward compatibility only. | |
778 function inverseModInt_(x,n) { | |
779 return inverseModInt(x,n); | |
780 } | |
781 | |
782 | |
783 //Given positive bigInts x and y, change the bigints v, a, and b to positive bigInts such that: | |
784 // v = GCD_(x,y) = a*x-b*y | |
785 //The bigInts v, a, b, must have exactly as many elements as the larger of x and y. | |
786 function eGCD_(x,y,v,a,b) { | |
787 var g=0; | |
788 var k=Math.max(x.length,y.length); | |
789 if (eg_u.length!=k) { | |
790 eg_u=new Array(k); | |
791 eg_A=new Array(k); | |
792 eg_B=new Array(k); | |
793 eg_C=new Array(k); | |
794 eg_D=new Array(k); | |
795 } | |
796 while(!(x[0]&1) && !(y[0]&1)) { //while x and y both even | |
797 halve_(x); | |
798 halve_(y); | |
799 g++; | |
800 } | |
801 copy_(eg_u,x); | |
802 copy_(v,y); | |
803 copyInt_(eg_A,1); | |
804 copyInt_(eg_B,0); | |
805 copyInt_(eg_C,0); | |
806 copyInt_(eg_D,1); | |
807 for (;;) { | |
808 while(!(eg_u[0]&1)) { //while u is even | |
809 halve_(eg_u); | |
810 if (!(eg_A[0]&1) && !(eg_B[0]&1)) { //if A==B==0 mod 2 | |
811 halve_(eg_A); | |
812 halve_(eg_B); | |
813 } else { | |
814 add_(eg_A,y); halve_(eg_A); | |
815 sub_(eg_B,x); halve_(eg_B); | |
816 } | |
817 } | |
818 | |
819 while (!(v[0]&1)) { //while v is even | |
820 halve_(v); | |
821 if (!(eg_C[0]&1) && !(eg_D[0]&1)) { //if C==D==0 mod 2 | |
822 halve_(eg_C); | |
823 halve_(eg_D); | |
824 } else { | |
825 add_(eg_C,y); halve_(eg_C); | |
826 sub_(eg_D,x); halve_(eg_D); | |
827 } | |
828 } | |
829 | |
830 if (!greater(v,eg_u)) { //v<=u | |
831 sub_(eg_u,v); | |
832 sub_(eg_A,eg_C); | |
833 sub_(eg_B,eg_D); | |
834 } else { //v>u | |
835 sub_(v,eg_u); | |
836 sub_(eg_C,eg_A); | |
837 sub_(eg_D,eg_B); | |
838 } | |
839 if (equalsInt(eg_u,0)) { | |
840 while (negative(eg_C)) { //make sure a (C) is nonnegative | |
841 add_(eg_C,y); | |
842 sub_(eg_D,x); | |
843 } | |
844 multInt_(eg_D,-1); ///make sure b (D) is nonnegative | |
845 copy_(a,eg_C); | |
846 copy_(b,eg_D); | |
847 leftShift_(v,g); | |
848 return; | |
849 } | |
850 } | |
851 } | |
852 | |
853 | |
854 //is bigInt x negative? | |
855 function negative(x) { | |
856 return ((x[x.length-1]>>(bpe-1))&1); | |
857 } | |
858 | |
859 | |
860 //is (x << (shift*bpe)) > y? | |
861 //x and y are nonnegative bigInts | |
862 //shift is a nonnegative integer | |
863 function greaterShift(x,y,shift) { | |
864 var i, kx=x.length, ky=y.length; | |
865 var k=((kx+shift)<ky) ? (kx+shift) : ky; | |
866 for (i=ky-1-shift; i<kx && i>=0; i++) | |
867 if (x[i]>0) | |
868 return 1; //if there are nonzeros in x to the left of the first column of y, then x is bigger | |
869 for (i=kx-1+shift; i<ky; i++) | |
870 if (y[i]>0) | |
871 return 0; //if there are nonzeros in y to the left of the first column of x, then x is not bigger | |
872 for (i=k-1; i>=shift; i--) | |
873 if (x[i-shift]>y[i]) return 1; | |
874 else if (x[i-shift]<y[i]) return 0; | |
875 return 0; | |
876 } | |
877 | |
878 //is x > y? (x and y both nonnegative) | |
879 function greater(x,y) { | |
880 var i; | |
881 var k=(x.length<y.length) ? x.length : y.length; | |
882 | |
883 for (i=x.length;i<y.length;i++) | |
884 if (y[i]) | |
885 return 0; //y has more digits | |
886 | |
887 for (i=y.length;i<x.length;i++) | |
888 if (x[i]) | |
889 return 1; //x has more digits | |
890 | |
891 for (i=k-1;i>=0;i--) | |
892 if (x[i]>y[i]) | |
893 return 1; | |
894 else if (x[i]<y[i]) | |
895 return 0; | |
896 return 0; | |
897 } | |
898 | |
899 //divide x by y giving quotient q and remainder r. (q=floor(x/y), r=x mod y). All 4 are bigints. | |
900 //x must have at least one leading zero element. | |
901 //y must be nonzero. | |
902 //q and r must be arrays that are exactly the same length as x. (Or q can have more). | |
903 //Must have x.length >= y.length >= 2. | |
904 function divide_(x,y,q,r) { | |
905 var kx, ky; | |
906 var i,j,y1,y2,c,a,b; | |
907 copy_(r,x); | |
908 for (ky=y.length;y[ky-1]==0;ky--); //ky is number of elements in y, not including leading zeros | |
909 | |
910 //normalize: ensure the most significant element of y has its highest bit set | |
911 b=y[ky-1]; | |
912 for (a=0; b; a++) | |
913 b>>=1; | |
914 a=bpe-a; //a is how many bits to shift so that the high order bit of y is leftmost in its array element | |
915 leftShift_(y,a); //multiply both by 1<<a now, then divide both by that at the end | |
916 leftShift_(r,a); | |
917 | |
918 //Rob Visser discovered a bug: the following line was originally just before the normalization. | |
919 for (kx=r.length;r[kx-1]==0 && kx>ky;kx--); //kx is number of elements in normalized x, not including leading zeros | |
920 | |
921 copyInt_(q,0); // q=0 | |
922 while (!greaterShift(y,r,kx-ky)) { // while (leftShift_(y,kx-ky) <= r) { | |
923 subShift_(r,y,kx-ky); // r=r-leftShift_(y,kx-ky) | |
924 q[kx-ky]++; // q[kx-ky]++; | |
925 } // } | |
926 | |
927 for (i=kx-1; i>=ky; i--) { | |
928 if (r[i]==y[ky-1]) | |
929 q[i-ky]=mask; | |
930 else | |
931 q[i-ky]=Math.floor((r[i]*radix+r[i-1])/y[ky-1]); | |
932 | |
933 //The following for(;;) loop is equivalent to the commented while loop, | |
934 //except that the uncommented version avoids overflow. | |
935 //The commented loop comes from HAC, which assumes r[-1]==y[-1]==0 | |
936 // while (q[i-ky]*(y[ky-1]*radix+y[ky-2]) > r[i]*radix*radix+r[i-1]*radix+r[i-2]) | |
937 // q[i-ky]--; | |
938 for (;;) { | |
939 y2=(ky>1 ? y[ky-2] : 0)*q[i-ky]; | |
940 c=y2; | |
941 y2=y2 & mask; | |
942 c = (c - y2) / radix; | |
943 y1=c+q[i-ky]*y[ky-1]; | |
944 c=y1; | |
945 y1=y1 & mask; | |
946 c = (c - y1) / radix; | |
947 | |
948 if (c==r[i] ? y1==r[i-1] ? y2>(i>1 ? r[i-2] : 0) : y1>r[i-1] : c>r[i]) | |
949 q[i-ky]--; | |
950 else | |
951 break; | |
952 } | |
953 | |
954 linCombShift_(r,y,-q[i-ky],i-ky); //r=r-q[i-ky]*leftShift_(y,i-ky) | |
955 if (negative(r)) { | |
956 addShift_(r,y,i-ky); //r=r+leftShift_(y,i-ky) | |
957 q[i-ky]--; | |
958 } | |
959 } | |
960 | |
961 rightShift_(y,a); //undo the normalization step | |
962 rightShift_(r,a); //undo the normalization step | |
963 } | |
964 | |
965 //do carries and borrows so each element of the bigInt x fits in bpe bits. | |
966 function carry_(x) { | |
967 var i,k,c,b; | |
968 k=x.length; | |
969 c=0; | |
970 for (i=0;i<k;i++) { | |
971 c+=x[i]; | |
972 b=0; | |
973 if (c<0) { | |
974 b = c & mask; | |
975 b = -((c - b) / radix); | |
976 c+=b*radix; | |
977 } | |
978 x[i]=c & mask; | |
979 c = ((c - x[i]) / radix) - b; | |
980 } | |
981 } | |
982 | |
983 //return x mod n for bigInt x and integer n. | |
984 function modInt(x,n) { | |
985 var i,c=0; | |
986 for (i=x.length-1; i>=0; i--) | |
987 c=(c*radix+x[i])%n; | |
988 return c; | |
989 } | |
990 | |
991 //convert the integer t into a bigInt with at least the given number of bits. | |
992 //the returned array stores the bigInt in bpe-bit chunks, little endian (buff[0] is least significant word) | |
993 //Pad the array with leading zeros so that it has at least minSize elements. | |
994 //There will always be at least one leading 0 element. | |
995 function int2bigInt(t,bits,minSize) { | |
996 var i,k, buff; | |
997 k=Math.ceil(bits/bpe)+1; | |
998 k=minSize>k ? minSize : k; | |
999 buff=new Array(k); | |
1000 copyInt_(buff,t); | |
1001 return buff; | |
1002 } | |
1003 | |
1004 //return the bigInt given a string representation in a given base. | |
1005 //Pad the array with leading zeros so that it has at least minSize elements. | |
1006 //If base=-1, then it reads in a space-separated list of array elements in decimal. | |
1007 //The array will always have at least one leading zero, unless base=-1. | |
1008 function str2bigInt(s,base,minSize) { | |
1009 var d, i, j, x, y, kk; | |
1010 var k=s.length; | |
1011 if (base==-1) { //comma-separated list of array elements in decimal | |
1012 x=new Array(0); | |
1013 for (;;) { | |
1014 y=new Array(x.length+1); | |
1015 for (i=0;i<x.length;i++) | |
1016 y[i+1]=x[i]; | |
1017 y[0]=parseInt(s,10); | |
1018 x=y; | |
1019 d=s.indexOf(',',0); | |
1020 if (d<1) | |
1021 break; | |
1022 s=s.substring(d+1); | |
1023 if (s.length==0) | |
1024 break; | |
1025 } | |
1026 if (x.length<minSize) { | |
1027 y=new Array(minSize); | |
1028 copy_(y,x); | |
1029 return y; | |
1030 } | |
1031 return x; | |
1032 } | |
1033 | |
1034 // log2(base)*k | |
1035 var bb = base, p = 0; | |
1036 var b = base == 1 ? k : 0; | |
1037 while (bb > 1) { | |
1038 if (bb & 1) p = 1; | |
1039 b += k; | |
1040 bb >>= 1; | |
1041 } | |
1042 b += p*k; | |
1043 | |
1044 x=int2bigInt(0,b,0); | |
1045 for (i=0;i<k;i++) { | |
1046 d=digitsStr.indexOf(s.substring(i,i+1),0); | |
1047 if (base<=36 && d>=36) //convert lowercase to uppercase if base<=36 | |
1048 d-=26; | |
1049 if (d>=base || d<0) { //stop at first illegal character | |
1050 break; | |
1051 } | |
1052 multInt_(x,base); | |
1053 addInt_(x,d); | |
1054 } | |
1055 | |
1056 for (k=x.length;k>0 && !x[k-1];k--); //strip off leading zeros | |
1057 k=minSize>k+1 ? minSize : k+1; | |
1058 y=new Array(k); | |
1059 kk=k<x.length ? k : x.length; | |
1060 for (i=0;i<kk;i++) | |
1061 y[i]=x[i]; | |
1062 for (;i<k;i++) | |
1063 y[i]=0; | |
1064 return y; | |
1065 } | |
1066 | |
1067 //is bigint x equal to integer y? | |
1068 //y must have less than bpe bits | |
1069 function equalsInt(x,y) { | |
1070 var i; | |
1071 if (x[0]!=y) | |
1072 return 0; | |
1073 for (i=1;i<x.length;i++) | |
1074 if (x[i]) | |
1075 return 0; | |
1076 return 1; | |
1077 } | |
1078 | |
1079 //are bigints x and y equal? | |
1080 //this works even if x and y are different lengths and have arbitrarily many leading zeros | |
1081 function equals(x,y) { | |
1082 var i; | |
1083 var k=x.length<y.length ? x.length : y.length; | |
1084 for (i=0;i<k;i++) | |
1085 if (x[i]!=y[i]) | |
1086 return 0; | |
1087 if (x.length>y.length) { | |
1088 for (;i<x.length;i++) | |
1089 if (x[i]) | |
1090 return 0; | |
1091 } else { | |
1092 for (;i<y.length;i++) | |
1093 if (y[i]) | |
1094 return 0; | |
1095 } | |
1096 return 1; | |
1097 } | |
1098 | |
1099 //is the bigInt x equal to zero? | |
1100 function isZero(x) { | |
1101 var i; | |
1102 for (i=0;i<x.length;i++) | |
1103 if (x[i]) | |
1104 return 0; | |
1105 return 1; | |
1106 } | |
1107 | |
1108 //convert a bigInt into a string in a given base, from base 2 up to base 95. | |
1109 //Base -1 prints the contents of the array representing the number. | |
1110 function bigInt2str(x,base) { | |
1111 var i,t,s=""; | |
1112 | |
1113 if (s6.length!=x.length) | |
1114 s6=dup(x); | |
1115 else | |
1116 copy_(s6,x); | |
1117 | |
1118 if (base==-1) { //return the list of array contents | |
1119 for (i=x.length-1;i>0;i--) | |
1120 s+=x[i]+','; | |
1121 s+=x[0]; | |
1122 } | |
1123 else { //return it in the given base | |
1124 while (!isZero(s6)) { | |
1125 t=divInt_(s6,base); //t=s6 % base; s6=floor(s6/base); | |
1126 s=digitsStr.substring(t,t+1)+s; | |
1127 } | |
1128 } | |
1129 if (s.length==0) | |
1130 s="0"; | |
1131 return s; | |
1132 } | |
1133 | |
1134 //returns a duplicate of bigInt x | |
1135 function dup(x) { | |
1136 var i, buff; | |
1137 buff=new Array(x.length); | |
1138 copy_(buff,x); | |
1139 return buff; | |
1140 } | |
1141 | |
1142 //do x=y on bigInts x and y. x must be an array at least as big as y (not counting the leading zeros in y). | |
1143 function copy_(x,y) { | |
1144 var i; | |
1145 var k=x.length<y.length ? x.length : y.length; | |
1146 for (i=0;i<k;i++) | |
1147 x[i]=y[i]; | |
1148 for (i=k;i<x.length;i++) | |
1149 x[i]=0; | |
1150 } | |
1151 | |
1152 //do x=y on bigInt x and integer y. | |
1153 function copyInt_(x,n) { | |
1154 var i,c; | |
1155 for (c=n,i=0;i<x.length;i++) { | |
1156 x[i]=c & mask; | |
1157 c>>=bpe; | |
1158 } | |
1159 } | |
1160 | |
1161 //do x=x+n where x is a bigInt and n is an integer. | |
1162 //x must be large enough to hold the result. | |
1163 function addInt_(x,n) { | |
1164 var i,k,c,b; | |
1165 x[0]+=n; | |
1166 k=x.length; | |
1167 c=0; | |
1168 for (i=0;i<k;i++) { | |
1169 c+=x[i]; | |
1170 b=0; | |
1171 if (c<0) { | |
1172 b = c & mask; | |
1173 b = -((c - b) / radix); | |
1174 c+=b*radix; | |
1175 } | |
1176 x[i]=c & mask; | |
1177 c = ((c - x[i]) / radix) - b; | |
1178 if (!c) return; //stop carrying as soon as the carry is zero | |
1179 } | |
1180 } | |
1181 | |
1182 //right shift bigInt x by n bits. | |
1183 function rightShift_(x,n) { | |
1184 var i; | |
1185 var k=Math.floor(n/bpe); | |
1186 if (k) { | |
1187 for (i=0;i<x.length-k;i++) //right shift x by k elements | |
1188 x[i]=x[i+k]; | |
1189 for (;i<x.length;i++) | |
1190 x[i]=0; | |
1191 n%=bpe; | |
1192 } | |
1193 for (i=0;i<x.length-1;i++) { | |
1194 x[i]=mask & ((x[i+1]<<(bpe-n)) | (x[i]>>n)); | |
1195 } | |
1196 x[i]>>=n; | |
1197 } | |
1198 | |
1199 //do x=floor(|x|/2)*sgn(x) for bigInt x in 2's complement | |
1200 function halve_(x) { | |
1201 var i; | |
1202 for (i=0;i<x.length-1;i++) { | |
1203 x[i]=mask & ((x[i+1]<<(bpe-1)) | (x[i]>>1)); | |
1204 } | |
1205 x[i]=(x[i]>>1) | (x[i] & (radix>>1)); //most significant bit stays the same | |
1206 } | |
1207 | |
1208 //left shift bigInt x by n bits. | |
1209 function leftShift_(x,n) { | |
1210 var i; | |
1211 var k=Math.floor(n/bpe); | |
1212 if (k) { | |
1213 for (i=x.length; i>=k; i--) //left shift x by k elements | |
1214 x[i]=x[i-k]; | |
1215 for (;i>=0;i--) | |
1216 x[i]=0; | |
1217 n%=bpe; | |
1218 } | |
1219 if (!n) | |
1220 return; | |
1221 for (i=x.length-1;i>0;i--) { | |
1222 x[i]=mask & ((x[i]<<n) | (x[i-1]>>(bpe-n))); | |
1223 } | |
1224 x[i]=mask & (x[i]<<n); | |
1225 } | |
1226 | |
1227 //do x=x*n where x is a bigInt and n is an integer. | |
1228 //x must be large enough to hold the result. | |
1229 function multInt_(x,n) { | |
1230 var i,k,c,b; | |
1231 if (!n) | |
1232 return; | |
1233 k=x.length; | |
1234 c=0; | |
1235 for (i=0;i<k;i++) { | |
1236 c+=x[i]*n; | |
1237 b=0; | |
1238 if (c<0) { | |
1239 b = c & mask; | |
1240 b = -((c - b) / radix); | |
1241 c+=b*radix; | |
1242 } | |
1243 x[i]=c & mask; | |
1244 c = ((c - x[i]) / radix) - b; | |
1245 } | |
1246 } | |
1247 | |
1248 //do x=floor(x/n) for bigInt x and integer n, and return the remainder | |
1249 function divInt_(x,n) { | |
1250 var i,r=0,s; | |
1251 for (i=x.length-1;i>=0;i--) { | |
1252 s=r*radix+x[i]; | |
1253 x[i]=Math.floor(s/n); | |
1254 r=s%n; | |
1255 } | |
1256 return r; | |
1257 } | |
1258 | |
1259 //do the linear combination x=a*x+b*y for bigInts x and y, and integers a and b. | |
1260 //x must be large enough to hold the answer. | |
1261 function linComb_(x,y,a,b) { | |
1262 var i,c,k,kk; | |
1263 k=x.length<y.length ? x.length : y.length; | |
1264 kk=x.length; | |
1265 for (c=0,i=0;i<k;i++) { | |
1266 c+=a*x[i]+b*y[i]; | |
1267 x[i]=c & mask; | |
1268 c = (c - x[i]) / radix; | |
1269 } | |
1270 for (i=k;i<kk;i++) { | |
1271 c+=a*x[i]; | |
1272 x[i]=c & mask; | |
1273 c = (c - x[i]) / radix; | |
1274 } | |
1275 } | |
1276 | |
1277 //do the linear combination x=a*x+b*(y<<(ys*bpe)) for bigInts x and y, and integers a, b and ys. | |
1278 //x must be large enough to hold the answer. | |
1279 function linCombShift_(x,y,b,ys) { | |
1280 var i,c,k,kk; | |
1281 k=x.length<ys+y.length ? x.length : ys+y.length; | |
1282 kk=x.length; | |
1283 for (c=0,i=ys;i<k;i++) { | |
1284 c+=x[i]+b*y[i-ys]; | |
1285 x[i]=c & mask; | |
1286 c = (c - x[i]) / radix; | |
1287 } | |
1288 for (i=k;c && i<kk;i++) { | |
1289 c+=x[i]; | |
1290 x[i]=c & mask; | |
1291 c = (c - x[i]) / radix; | |
1292 } | |
1293 } | |
1294 | |
1295 //do x=x+(y<<(ys*bpe)) for bigInts x and y, and integers a,b and ys. | |
1296 //x must be large enough to hold the answer. | |
1297 function addShift_(x,y,ys) { | |
1298 var i,c,k,kk; | |
1299 k=x.length<ys+y.length ? x.length : ys+y.length; | |
1300 kk=x.length; | |
1301 for (c=0,i=ys;i<k;i++) { | |
1302 c+=x[i]+y[i-ys]; | |
1303 x[i]=c & mask; | |
1304 c = (c - x[i]) / radix; | |
1305 } | |
1306 for (i=k;c && i<kk;i++) { | |
1307 c+=x[i]; | |
1308 x[i]=c & mask; | |
1309 c = (c - x[i]) / radix; | |
1310 } | |
1311 } | |
1312 | |
1313 //do x=x-(y<<(ys*bpe)) for bigInts x and y, and integers a,b and ys. | |
1314 //x must be large enough to hold the answer. | |
1315 function subShift_(x,y,ys) { | |
1316 var i,c,k,kk; | |
1317 k=x.length<ys+y.length ? x.length : ys+y.length; | |
1318 kk=x.length; | |
1319 for (c=0,i=ys;i<k;i++) { | |
1320 c+=x[i]-y[i-ys]; | |
1321 x[i]=c & mask; | |
1322 c = (c - x[i]) / radix; | |
1323 } | |
1324 for (i=k;c && i<kk;i++) { | |
1325 c+=x[i]; | |
1326 x[i]=c & mask; | |
1327 c = (c - x[i]) / radix; | |
1328 } | |
1329 } | |
1330 | |
1331 //do x=x-y for bigInts x and y. | |
1332 //x must be large enough to hold the answer. | |
1333 //negative answers will be 2s complement | |
1334 function sub_(x,y) { | |
1335 var i,c,k,kk; | |
1336 k=x.length<y.length ? x.length : y.length; | |
1337 for (c=0,i=0;i<k;i++) { | |
1338 c+=x[i]-y[i]; | |
1339 x[i]=c & mask; | |
1340 c = (c - x[i]) / radix; | |
1341 } | |
1342 for (i=k;c && i<x.length;i++) { | |
1343 c+=x[i]; | |
1344 x[i]=c & mask; | |
1345 c = (c - x[i]) / radix; | |
1346 } | |
1347 } | |
1348 | |
1349 //do x=x+y for bigInts x and y. | |
1350 //x must be large enough to hold the answer. | |
1351 function add_(x,y) { | |
1352 var i,c,k,kk; | |
1353 k=x.length<y.length ? x.length : y.length; | |
1354 for (c=0,i=0;i<k;i++) { | |
1355 c+=x[i]+y[i]; | |
1356 x[i]=c & mask; | |
1357 c = (c - x[i]) / radix; | |
1358 } | |
1359 for (i=k;c && i<x.length;i++) { | |
1360 c+=x[i]; | |
1361 x[i]=c & mask; | |
1362 c = (c - x[i]) / radix; | |
1363 } | |
1364 } | |
1365 | |
1366 //do x=x*y for bigInts x and y. This is faster when y<x. | |
1367 function mult_(x,y) { | |
1368 var i; | |
1369 if (ss.length!=2*x.length) | |
1370 ss=new Array(2*x.length); | |
1371 copyInt_(ss,0); | |
1372 for (i=0;i<y.length;i++) | |
1373 if (y[i]) | |
1374 linCombShift_(ss,x,y[i],i); //ss=1*ss+y[i]*(x<<(i*bpe)) | |
1375 copy_(x,ss); | |
1376 } | |
1377 | |
1378 //do x=x mod n for bigInts x and n. | |
1379 function mod_(x,n) { | |
1380 if (s4.length!=x.length) | |
1381 s4=dup(x); | |
1382 else | |
1383 copy_(s4,x); | |
1384 if (s5.length!=x.length) | |
1385 s5=dup(x); | |
1386 divide_(s4,n,s5,x); //x = remainder of s4 / n | |
1387 } | |
1388 | |
1389 //do x=x*y mod n for bigInts x,y,n. | |
1390 //for greater speed, let y<x. | |
1391 function multMod_(x,y,n) { | |
1392 var i; | |
1393 if (s0.length!=2*x.length) | |
1394 s0=new Array(2*x.length); | |
1395 copyInt_(s0,0); | |
1396 for (i=0;i<y.length;i++) | |
1397 if (y[i]) | |
1398 linCombShift_(s0,x,y[i],i); //s0=1*s0+y[i]*(x<<(i*bpe)) | |
1399 mod_(s0,n); | |
1400 copy_(x,s0); | |
1401 } | |
1402 | |
1403 //do x=x*x mod n for bigInts x,n. | |
1404 function squareMod_(x,n) { | |
1405 var i,j,d,c,kx,kn,k; | |
1406 for (kx=x.length; kx>0 && !x[kx-1]; kx--); //ignore leading zeros in x | |
1407 k=kx>n.length ? 2*kx : 2*n.length; //k=# elements in the product, which is twice the elements in the larger of x and n | |
1408 if (s0.length!=k) | |
1409 s0=new Array(k); | |
1410 copyInt_(s0,0); | |
1411 for (i=0;i<kx;i++) { | |
1412 c=s0[2*i]+x[i]*x[i]; | |
1413 s0[2*i]=c & mask; | |
1414 c = (c - s0[2*i]) / radix; | |
1415 for (j=i+1;j<kx;j++) { | |
1416 c=s0[i+j]+2*x[i]*x[j]+c; | |
1417 s0[i+j]=(c & mask); | |
1418 c = (c - s0[i+j]) / radix; | |
1419 } | |
1420 s0[i+kx]=c; | |
1421 } | |
1422 mod_(s0,n); | |
1423 copy_(x,s0); | |
1424 } | |
1425 | |
1426 //return x with exactly k leading zero elements | |
1427 function trim(x,k) { | |
1428 var i,y; | |
1429 for (i=x.length; i>0 && !x[i-1]; i--); | |
1430 y=new Array(i+k); | |
1431 copy_(y,x); | |
1432 return y; | |
1433 } | |
1434 | |
1435 //do x=x**y mod n, where x,y,n are bigInts and ** is exponentiation. 0**0=1. | |
1436 //this is faster when n is odd. x usually needs to have as many elements as n. | |
1437 function powMod_(x,y,n) { | |
1438 var k1,k2,kn,np; | |
1439 if(s7.length!=n.length) | |
1440 s7=dup(n); | |
1441 | |
1442 //for even modulus, use a simple square-and-multiply algorithm, | |
1443 //rather than using the more complex Montgomery algorithm. | |
1444 if ((n[0]&1)==0) { | |
1445 copy_(s7,x); | |
1446 copyInt_(x,1); | |
1447 while(!equalsInt(y,0)) { | |
1448 if (y[0]&1) | |
1449 multMod_(x,s7,n); | |
1450 divInt_(y,2); | |
1451 squareMod_(s7,n); | |
1452 } | |
1453 return; | |
1454 } | |
1455 | |
1456 //calculate np from n for the Montgomery multiplications | |
1457 copyInt_(s7,0); | |
1458 for (kn=n.length;kn>0 && !n[kn-1];kn--); | |
1459 np=radix-inverseModInt(modInt(n,radix),radix); | |
1460 s7[kn]=1; | |
1461 multMod_(x ,s7,n); // x = x * 2**(kn*bp) mod n | |
1462 | |
1463 if (s3.length!=x.length) | |
1464 s3=dup(x); | |
1465 else | |
1466 copy_(s3,x); | |
1467 | |
1468 for (k1=y.length-1;k1>0 & !y[k1]; k1--); //k1=first nonzero element of y | |
1469 if (y[k1]==0) { //anything to the 0th power is 1 | |
1470 copyInt_(x,1); | |
1471 return; | |
1472 } | |
1473 for (k2=1<<(bpe-1);k2 && !(y[k1] & k2); k2>>=1); //k2=position of first 1 bit in y[k1] | |
1474 for (;;) { | |
1475 if (!(k2>>=1)) { //look at next bit of y | |
1476 k1--; | |
1477 if (k1<0) { | |
1478 mont_(x,one,n,np); | |
1479 return; | |
1480 } | |
1481 k2=1<<(bpe-1); | |
1482 } | |
1483 mont_(x,x,n,np); | |
1484 | |
1485 if (k2 & y[k1]) //if next bit is a 1 | |
1486 mont_(x,s3,n,np); | |
1487 } | |
1488 } | |
1489 | |
1490 | |
1491 //do x=x*y*Ri mod n for bigInts x,y,n, | |
1492 // where Ri = 2**(-kn*bpe) mod n, and kn is the | |
1493 // number of elements in the n array, not | |
1494 // counting leading zeros. | |
1495 //x array must have at least as many elemnts as the n array | |
1496 //It's OK if x and y are the same variable. | |
1497 //must have: | |
1498 // x,y < n | |
1499 // n is odd | |
1500 // np = -(n^(-1)) mod radix | |
1501 function mont_(x,y,n,np) { | |
1502 var i,j,c,ui,t,t2,ks; | |
1503 var kn=n.length; | |
1504 var ky=y.length; | |
1505 | |
1506 if (sa.length!=kn) | |
1507 sa=new Array(kn); | |
1508 | |
1509 copyInt_(sa,0); | |
1510 | |
1511 for (;kn>0 && n[kn-1]==0;kn--); //ignore leading zeros of n | |
1512 for (;ky>0 && y[ky-1]==0;ky--); //ignore leading zeros of y | |
1513 ks=sa.length-1; //sa will never have more than this many nonzero elements. | |
1514 | |
1515 //the following loop consumes 95% of the runtime for randTruePrime_() and powMod_() for large numbers | |
1516 for (i=0; i<kn; i++) { | |
1517 t=sa[0]+x[i]*y[0]; | |
1518 ui=((t & mask) * np) & mask; //the inner "& mask" was needed on Safari (but not MSIE) at one time | |
1519 c=(t+ui*n[0]); | |
1520 c = (c - (c & mask)) / radix; | |
1521 t=x[i]; | |
1522 | |
1523 //do sa=(sa+x[i]*y+ui*n)/b where b=2**bpe. Loop is unrolled 5-fold for speed | |
1524 j=1; | |
1525 for (;j<ky-4;) { | |
1526 c+=sa[j]+ui*n[j]+t*y[j]; t2=sa[j-1]=c & mask; c=(c-t2)/radix; j++; | |
1527 c+=sa[j]+ui*n[j]+t*y[j]; t2=sa[j-1]=c & mask; c=(c-t2)/radix; j++; | |
1528 c+=sa[j]+ui*n[j]+t*y[j]; t2=sa[j-1]=c & mask; c=(c-t2)/radix; j++; | |
1529 c+=sa[j]+ui*n[j]+t*y[j]; t2=sa[j-1]=c & mask; c=(c-t2)/radix; j++; | |
1530 c+=sa[j]+ui*n[j]+t*y[j]; t2=sa[j-1]=c & mask; c=(c-t2)/radix; j++; | |
1531 } | |
1532 for (;j<ky;) { | |
1533 c+=sa[j]+ui*n[j]+t*y[j]; t2=sa[j-1]=c & mask; c=(c-t2)/radix; j++; | |
1534 } | |
1535 for (;j<kn-4;) { | |
1536 c+=sa[j]+ui*n[j]; t2=sa[j-1]=c & mask; c=(c-t2)/radix; j++; | |
1537 c+=sa[j]+ui*n[j]; t2=sa[j-1]=c & mask; c=(c-t2)/radix; j++; | |
1538 c+=sa[j]+ui*n[j]; t2=sa[j-1]=c & mask; c=(c-t2)/radix; j++; | |
1539 c+=sa[j]+ui*n[j]; t2=sa[j-1]=c & mask; c=(c-t2)/radix; j++; | |
1540 c+=sa[j]+ui*n[j]; t2=sa[j-1]=c & mask; c=(c-t2)/radix; j++; | |
1541 } | |
1542 for (;j<kn;) { | |
1543 c+=sa[j]+ui*n[j]; t2=sa[j-1]=c & mask; c=(c-t2)/radix; j++; | |
1544 } | |
1545 for (;j<ks;) { | |
1546 c+=sa[j]; t2=sa[j-1]=c & mask; c=(c-t2)/radix; j++; | |
1547 } | |
1548 sa[j-1]=c & mask; | |
1549 } | |
1550 | |
1551 if (!greater(n,sa)) | |
1552 sub_(sa,n); | |
1553 copy_(x,sa); | |
1554 } | |
1555 | |
1556 | |
1557 // otr.js additions | |
1558 | |
1559 | |
1560 // computes num / den mod n | |
1561 function divMod(num, den, n) { | |
1562 return multMod(num, inverseMod(den, n), n) | |
1563 } | |
1564 | |
1565 // computes one - two mod n | |
1566 function subMod(one, two, n) { | |
1567 one = mod(one, n) | |
1568 two = mod(two, n) | |
1569 if (greater(two, one)) one = add(one, n) | |
1570 return sub(one, two) | |
1571 } | |
1572 | |
1573 // computes 2^m as a bigInt | |
1574 function twoToThe(m) { | |
1575 var b = Math.floor(m / bpe) + 2 | |
1576 var t = new Array(b) | |
1577 for (var i = 0; i < b; i++) t[i] = 0 | |
1578 t[b - 2] = 1 << (m % bpe) | |
1579 return t | |
1580 } | |
1581 | |
1582 // cache these results for faster lookup | |
1583 var _num2bin = (function () { | |
1584 var i = 0, _num2bin= {} | |
1585 for (; i < 0x100; ++i) { | |
1586 _num2bin[i] = String.fromCharCode(i) // 0 -> "\00" | |
1587 } | |
1588 return _num2bin | |
1589 }()) | |
1590 | |
1591 // serialize a bigInt to an ascii string | |
1592 // padded up to pad length | |
1593 function bigInt2bits(bi, pad) { | |
1594 pad || (pad = 0) | |
1595 bi = dup(bi) | |
1596 var ba = '' | |
1597 while (!isZero(bi)) { | |
1598 ba = _num2bin[bi[0] & 0xff] + ba | |
1599 rightShift_(bi, 8) | |
1600 } | |
1601 while (ba.length < pad) { | |
1602 ba = '\x00' + ba | |
1603 } | |
1604 return ba | |
1605 } | |
1606 | |
1607 // converts a byte array to a bigInt | |
1608 function ba2bigInt(data) { | |
1609 var mpi = str2bigInt('0', 10, data.length) | |
1610 data.forEach(function (d, i) { | |
1611 if (i) leftShift_(mpi, 8) | |
1612 mpi[0] |= d | |
1613 }) | |
1614 return mpi | |
1615 } | |
1616 | |
1617 // returns a function that returns an array of n bytes | |
1618 var randomBytes = (function () { | |
1619 | |
1620 // in node | |
1621 if ( typeof crypto !== 'undefined' && | |
1622 typeof crypto.randomBytes === 'function' ) { | |
1623 return function (n) { | |
1624 try { | |
1625 var buf = crypto.randomBytes(n) | |
1626 } catch (e) { throw e } | |
1627 return Array.prototype.slice.call(buf, 0) | |
1628 } | |
1629 } | |
1630 | |
1631 // in browser | |
1632 else if ( typeof crypto !== 'undefined' && | |
1633 typeof crypto.getRandomValues === 'function' ) { | |
1634 return function (n) { | |
1635 var buf = new Uint8Array(n) | |
1636 crypto.getRandomValues(buf) | |
1637 return Array.prototype.slice.call(buf, 0) | |
1638 } | |
1639 } | |
1640 | |
1641 // err | |
1642 else { | |
1643 throw new Error('Keys should not be generated without CSPRNG.') | |
1644 } | |
1645 | |
1646 }()) | |
1647 | |
1648 // Salsa 20 in webworker needs a 40 byte seed | |
1649 function getSeed() { | |
1650 return randomBytes(40) | |
1651 } | |
1652 | |
1653 // returns a single random byte | |
1654 function randomByte() { | |
1655 return randomBytes(1)[0] | |
1656 } | |
1657 | |
1658 // returns a k-bit random integer | |
1659 function randomBitInt(k) { | |
1660 if (k > 31) throw new Error("Too many bits.") | |
1661 var i = 0, r = 0 | |
1662 var b = Math.floor(k / 8) | |
1663 var mask = (1 << (k % 8)) - 1 | |
1664 if (mask) r = randomByte() & mask | |
1665 for (; i < b; i++) | |
1666 r = (256 * r) + randomByte() | |
1667 return r | |
1668 } | |
1669 | |
1670 return { | |
1671 str2bigInt : str2bigInt | |
1672 , bigInt2str : bigInt2str | |
1673 , int2bigInt : int2bigInt | |
1674 , multMod : multMod | |
1675 , powMod : powMod | |
1676 , inverseMod : inverseMod | |
1677 , randBigInt : randBigInt | |
1678 , randBigInt_ : randBigInt_ | |
1679 , equals : equals | |
1680 , equalsInt : equalsInt | |
1681 , sub : sub | |
1682 , mod : mod | |
1683 , modInt : modInt | |
1684 , mult : mult | |
1685 , divInt_ : divInt_ | |
1686 , rightShift_ : rightShift_ | |
1687 , dup : dup | |
1688 , greater : greater | |
1689 , add : add | |
1690 , isZero : isZero | |
1691 , bitSize : bitSize | |
1692 , millerRabin : millerRabin | |
1693 , divide_ : divide_ | |
1694 , trim : trim | |
1695 , primes : primes | |
1696 , findPrimes : findPrimes | |
1697 , getSeed : getSeed | |
1698 , divMod : divMod | |
1699 , subMod : subMod | |
1700 , twoToThe : twoToThe | |
1701 , bigInt2bits : bigInt2bits | |
1702 , ba2bigInt : ba2bigInt | |
1703 } | |
1704 | |
1705 })) |