1Bignum(3) User Contributed Perl Documentation Bignum(3)
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6 Crypt::OpenSSL::Bignum - OpenSSL's multiprecision integer arithmetic
7
9 use Crypt::OpenSSL::Bignum;
10 my $bn = Crypt::OpenSSL::Bignum->new_from_decimal( "1000" );
12 # or
13 my $bn = Crypt::OpenSSL::Bignum->new_from_word( 1000 );
14 # or
15 my $bn = Crypt::OpenSSL::Bignum->new_from_hex("0x3e8");
16 # or
17 my $bn = Crypt::OpenSSL::Bignum->new_from_bin(pack( "C*", 3, 232 ))
18 use Crypt::OpenSSL::Bignum::CTX;
20 sub print_factorial
22 {
23 my( $n ) = @_;
24 my $fac = Crypt::OpenSSL::Bignum->one();
25 my $ctx = Crypt::OpenSSL::Bignum::CTX->new();
26 foreach my $i (1 .. $n)
27 {
28 $fac->mul( Crypt::OpenSSL::Bignum->new_from_word( $i ), $ctx, $fac );
29 }
30 print "$n factorial is ", $fac->to_decimal(), "\n";
31 }
32
34 Crypt::OpenSSL::Bignum provides access to OpenSSL multiprecision
35 integer arithmetic libraries. Presently, many though not all of the
36 arithmetic operations that OpenSSL provides are exposed to perl. In
37 addition, this module can be used to provide access to bignum values
38 produced by other OpenSSL modules, such as key parameters from
39 Crypt::OpenSSL::RSA.
40 NOTE: Many of the methods in this package can croak, so use eval, or
42 Error.pm's try/catch mechanism to capture errors.
43
45 new_from_word
46 Create a new Crypt::OpenSSL::Bignum object whose value will be the
47 word given. Note that numbers represneted by objects created using
48 this method are necessarily between 0 and 2^32 - 1.
49 new_from_decimal
51 Create a new Crypt::OpenSSL::Bignum object whose value is specified
52 by the given decimal representation.
53 new_from_hex
55 Create a new Crypt::OpenSSL::Bignum object whose value is specified
56 by the given hexidecimal representation.
57 new_from_bin
59 Create a new Crypt::OpenSSL::Bignum object whose value is specified
60 by the given packed binary string. Note that objects created using
61 this method are necessarily nonnegative.
62 zero
64 Returns a new Crypt::OpenSSL::Bignum object representing 0
65 one Returns a new Crypt::OpenSSL::Bignum object representing 1
67 bless_pointer
69 Given a pointer to a OpenSSL BIGNUM object in memory, construct and
70 return Crypt::OpenSSL::Bignum object around this. Note that the
71 underlying BIGNUM object will be destroyed (via
72 BN_clear_free(3ssl)) when the returned Crypt::OpenSSL::Bignum
73 object is no longer referenced, so the pointer passed to this
74 method should only be referenced via the returned perl object after
75 calling bless_pointer.
76 This method is intended only for use by XSUB writers writing code
78 that interfaces with OpenSSL library methods, and who wish to be
79 able to return a BIGNUM structure to perl as a
80 Crypt::OpenSSL::Bignum object.
81
83 to_decimal
84 Return a decimal string representation of this object.
85 to_hex
87 Return a hexidecimal string representation of this object.
88 to_bin
90 Return a packed binary string representation of this object. Note
91 that sign is ignored, so that to bin called on a
92 Crypt::OpenSSL::Bignum object representing a negative number
93 returns the same value as it would called on an object representing
94 that number's absolute value.
95 get_word
97 Return a scalar integer representation of this object, if it can be
98 represented as an unsigned long.
99 is_zero
101 Returns true of this object represents 0.
102 is_one
104 Returns true of this object represents 1.
105 is_odd
107 Returns true of this object represents an odd number.
108 copy
110 Returns a copy of this object.
111 add This method returns the sum of this object and the first argument.
113 If only one argument is passed, a new Crypt::OpenSSL::Bignum object
114 is created for the return value; otherwise, the value of second
115 argument is set to the result and returned.
116 sub This method returns the difference of this object and the first
118 argument. If only one argument is passed, a new
119 Crypt::OpenSSL::Bignum object is created for the return value;
120 otherwise, the value of second argument is set to the result and
121 returned.
122 mul This method returns the product of this object and the first
124 argument, using the second argument, a Crypt::OpenSSL::Bignum::CTX
125 object, as a scratchpad. If only two arguments are passed, a new
126 Crypt::OpenSSL::Bignum object is created for the return value;
127 otherwise, the value of third argument is set to the result and
128 returned.
129 div This method returns a list consisting of quotient and the remainder
131 obtained by dividing this object by the first argument, using the
132 second argument, a Crypt::OpenSSL::Bignum::CTX object, as a
133 scratchpad. If only two arguments are passed, new
134 Crypt::OpenSSL::Bignum objects is created for both return values.
135 If a third argument is passed, otherwise, the value of third
136 argument is set to the quotient. If a fourth argument is passed,
137 the value of the fourth argument is set to the remainder.
138 exp This method returns the product of this object exponeniated by the
140 first argument, using the second argument, a
141 Crypt::OpenSSL::Bignum::CTX object, as a scratchpad.
142 mod_exp
144 This method returns the product of this object exponeniated by the
145 first argument, modulo the second argument, using the third
146 argument, a Crypt::OpenSSL::Bignum::CTX object, as a scratchpad.
147 pointer_copy
149 This method is intended only for use by XSUB writers wanting to
150 have access to the underlying BIGNUM structure referenced by a
151 Crypt::OpenSSL::Bignum perl object so that they can pass them to
152 other routines in the OpenSSL library. It returns a perl scalar
153 whose IV can be cast to a BIGNUM* value. This can then be passed
154 to an XSUB which can work with the BIGNUM directly. Note that the
155 BIGNUM object pointed to will be a copy of the BIGNUM object
156 wrapped by the instance; it is thus the responsiblity of the client
157 to free space allocated by this BIGNUM object if and when it is
158 done with it. See also bless_pointer.
159
161 Ian Robertson, iroberts@cpan.org
162
164 perl, bn(3ssl)
165perl v5.12.0 2007-05-20 Bignum(3)