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-rw-r--r--lib/ssh/src/ssh_math.erl96
1 files changed, 3 insertions, 93 deletions
diff --git a/lib/ssh/src/ssh_math.erl b/lib/ssh/src/ssh_math.erl
index 4aa385b18d..e05964daa1 100644
--- a/lib/ssh/src/ssh_math.erl
+++ b/lib/ssh/src/ssh_math.erl
@@ -1,7 +1,7 @@
%%
%% %CopyrightBegin%
%%
-%% Copyright Ericsson AB 2005-2011. All Rights Reserved.
+%% Copyright Ericsson AB 2005-2013. All Rights Reserved.
%%
%% The contents of this file are subject to the Erlang Public License,
%% Version 1.1, (the "License"); you may not use this file except in
@@ -23,109 +23,19 @@
-module(ssh_math).
--export([ilog2/1, ipow/3, invert/2, ipow2/3]).
+-export([ipow/3]).
-
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%
%% INTEGER utils
%%
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
-%% number of bits (used) in a integer = isize(N) = |log2(N)|+1
-ilog2(N) ->
- ssh_bits:isize(N) - 1.
-
-
%% calculate A^B mod M
ipow(A, B, M) when M > 0, B >= 0 ->
- crypto:mod_exp(A, B, M).
-
-ipow2(A, B, M) when M > 0, B >= 0 ->
- if A == 1 ->
- 1;
- true ->
- ipow2(A, B, M, 1)
- end.
-
-ipow2(A, 1, M, Prod) ->
- (A*Prod) rem M;
-ipow2(_A, 0, _M, Prod) ->
- Prod;
-ipow2(A, B, M, Prod) ->
- B1 = B bsr 1,
- A1 = (A*A) rem M,
- if B - B1 == B1 ->
- ipow2(A1, B1, M, Prod);
- true ->
- ipow2(A1, B1, M, (A*Prod) rem M)
- end.
-
-%% %%
-%% %% Normal gcd
-%% %%
-%% gcd(R, Q) when abs(Q) < abs(R) -> gcd1(Q,R);
-%% gcd(R, Q) -> gcd1(R,Q).
-
-%% gcd1(0, Q) -> Q;
-%% gcd1(R, Q) ->
-%% gcd1(Q rem R, R).
-
-
-%% %%
-%% %% Least common multiple of (R,Q)
-%% %%
-%% lcm(0, _Q) -> 0;
-%% lcm(_R, 0) -> 0;
-%% lcm(R, Q) ->
-%% (Q div gcd(R, Q)) * R.
-
-%% %%
-%% %% Extended gcd gcd(R,Q) -> {G, {A,B}} such that G == R*A + Q*B
-%% %%
-%% %% Here we could have use for a bif divrem(Q, R) -> {Quote, Remainder}
-%% %%
-%% egcd(R,Q) when abs(Q) < abs(R) -> egcd1(Q,R,1,0,0,1);
-%% egcd(R,Q) -> egcd1(R,Q,0,1,1,0).
-
-%% egcd1(0,Q,_,_,Q1,Q2) -> {Q, {Q2,Q1}};
-%% egcd1(R,Q,R1,R2,Q1,Q2) ->
-%% D = Q div R,
-%% egcd1(Q rem R, R, Q1-D*R1, Q2-D*R2, R1, R2).
-
-%%
-%% Invert an element X mod P
-%% Calculated as {1, {A,B}} = egcd(X,P),
-%% 1 == P*A + X*B == X*B (mod P) i.e B is the inverse element
-%%
-%% X > 0, P > 0, X < P (P should be prime)
-%%
-invert(X,P) when X > 0, P > 0, X < P ->
- I = inv(X,P,1,0),
- if
- I < 0 -> P + I;
- true -> I
- end.
-
-inv(0,_,_,Q) -> Q;
-inv(X,P,R1,Q1) ->
- D = P div X,
- inv(P rem X, X, Q1 - D*R1, R1).
-
+ crypto:binary_to_integer(crypto:mod_pow(A, B, M)).
-%% %%
-%% %% Integer square root
-%% %%
-%% isqrt(0) -> 0;
-%% isqrt(1) -> 1;
-%% isqrt(X) when X >= 0 ->
-%% R = X div 2,
-%% isqrt(X div R, R, X).
-%% isqrt(Q,R,X) when Q < R ->
-%% R1 = (R+Q) div 2,
-%% isqrt(X div R1, R1, X);
-%% isqrt(_, R, _) -> R.