This section describes primitives for performing arithmetic operations with integer big numbers of variable length.
The full list of functions for big number arithmetic is given in Table “Intel IPP Big Number Arithmetic Functions”.
| Function Base Name | Operation |
|---|---|
| Unsigned Big Number Arithmetic Functions | |
| Add_BNU | Adds two unsigned integer big numbers of the same length. |
| Sub_BNU | Subtracts one integer big number from another integer big number of the same length. |
| MulOne_BNU | Multiplies unsigned integer big number by 32-bit unsigned integer. |
| MACOne_BNU_I | Computes multiplication of unsigned integer big number by 32-bit integer and accumulates the result with another integer big number. |
| Mul_BNU4 | Multiplies two unsigned integers of 4*32 bits. |
| Mul_BNU8 | Multiplies two unsigned integers of 8*32 bits. |
| Div_64u32u | Divides unsigned 64-bit integer by unsigned 32-bit integer. |
| Sqr_32u64u | Computes the square of 32-bit words in the input array. |
| Sqr_BNU4 | Computes the square of an unsigned integer big number of 4*32 bits. |
| Sqr_BNU8 | Computes the square of an unsigned integer big number of 8*32 bits. |
| SetOctString_BNU | Converts octet string into unsigned integer big number. |
| GetOctString_BNU | Converts unsigned integer big number into octet string. |
| Signed Big Number Arithmetic Functions | |
| BigNumGetSize | Gets the size of the IppsBigNumState context. |
| BigNumInit | Initializes context and partitions allocated buffer. |
| Set_BN | Defines the sign and value of the context. |
| SetOctString_BN | Converts octet string into a positive Big Number. |
| GetSize_BN | Returns the maximum length of the integer big number the structure can store. |
| Get_BN | Extracts the sign and value of the integer big number from the input structure. |
| ExtGet_BN | Extracts the specified combination of the sign, data length, and value characteristics of the integer big number from the input structure. |
| Ref_BN | Extracts the main characteristics of the integer big number from the input structure. |
| GetOctString_BN | Converts a positive Big Number into octet String. |
| Cmp_BN | Compares two Big Numbers. |
| CmpZero_BN | Checks the value of the input data field. |
| Add_BN | Adds two integer big numbers. |
| Sub_BN | Subtracts one integer big number from another. |
| Mul_BN | Multiplies two integer big numbers. |
| MAC_BN_I | Multiplies two integer big numbers and accumulates the result with the third integer big number. |
| Div_BN | Divides one integer big number by another. |
| Mod_BN | Computes modular reduction for input integer big number with respect to specified modulus. |
| Gcd_BN | Computes the greatest common divisor. |
| ModInv_BN | Computes multiplicative inverse of a positive integer big number with respect to specified modulus. |
The magnitude of an integer big number is specified by
an array of unsigned integer data type
Ipp32u
rp
[length] and corresponds to the
mathematical value
This section uses the following definition for the sign of an integer big number:
typedef enum {
IppsBigNumNEG=0,
IppsBigNumPOS=1
} IppsBigNumSGN;
The functions described in this section use the context IppsBigNumState to serve as an operational vehicle that carries not only the sign and value of the data, but also a sufficient working buffer reserved for various arithmetic operations. The length of the context IppsBigNumState is defined as the length of the data carried by the structure and the size of the context IppsBigNumState is therefore defined as the maximal length of the data that this operational vehicle can carry.
Note
In all unsigned big number arithmetic functions described below, integers pointed to by a, b, and r are all of (n*32) bits.