hashing::sha256::Hash Class Reference

Contains hash array and functions to update it and convert it to a hexadecimal string. More...

Collaboration diagram for hashing::sha256::Hash:

Public Member Functions
void	update (const std::array< uint32_t, 64 > &blocks)
	Updates the hash array.
std::string	to_string () const
	Convert the hash to a hexadecimal string.

Private Attributes
std::array< uint32_t, 8 >	hash

Detailed Description

Contains hash array and functions to update it and convert it to a hexadecimal string.

Member Function Documentation

to_string()

std::string hashing::sha256::Hash::to_string

(

)

const

Convert the hash to a hexadecimal string.

Returns

std::string Final hash value

                                {
    std::stringstream ss;
    for (size_t i = 0; i < 8; ++i) {
        ss << std::hex << std::setfill('0') << std::setw(8) << hash[i];
    }
    return ss.str();
}

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update()

void hashing::sha256::Hash::update

(

const std::array< uint32_t, 64 > &

blocks

)

Updates the hash array.

Parameters

blocks

Message schedule array

Returns

void

                                                      {
    // Initialize array of round constants with first 32 bits of the fractional
    // parts of the cube roots of the first 64 primes 2..311
    const std::array<uint32_t, 64> round_constants = {
        0x428A2F98, 0x71374491, 0xB5C0FBCF, 0xE9B5DBA5, 0x3956C25B, 0x59F111F1,
        0x923F82A4, 0xAB1C5ED5, 0xD807AA98, 0x12835B01, 0x243185BE, 0x550C7DC3,
        0x72BE5D74, 0x80DEB1FE, 0x9BDC06A7, 0xC19BF174, 0xE49B69C1, 0xEFBE4786,
        0x0FC19DC6, 0x240CA1CC, 0x2DE92C6F, 0x4A7484AA, 0x5CB0A9DC, 0x76F988DA,
        0x983E5152, 0xA831C66D, 0xB00327C8, 0xBF597FC7, 0xC6E00BF3, 0xD5A79147,
        0x06CA6351, 0x14292967, 0x27B70A85, 0x2E1B2138, 0x4D2C6DFC, 0x53380D13,
        0x650A7354, 0x766A0ABB, 0x81C2C92E, 0x92722C85, 0xA2BFE8A1, 0xA81A664B,
        0xC24B8B70, 0xC76C51A3, 0xD192E819, 0xD6990624, 0xF40E3585, 0x106AA070,
        0x19A4C116, 0x1E376C08, 0x2748774C, 0x34B0BCB5, 0x391C0CB3, 0x4ED8AA4A,
        0x5B9CCA4F, 0x682E6FF3, 0x748F82EE, 0x78A5636F, 0x84C87814, 0x8CC70208,
        0x90BEFFFA, 0xA4506CEB, 0xBEF9A3F7, 0xC67178F2};
 
    // Initialize working variables
    auto a = hash[0];
    auto b = hash[1];
    auto c = hash[2];
    auto d = hash[3];
    auto e = hash[4];
    auto f = hash[5];
    auto g = hash[6];
    auto h = hash[7];
 
    // Compression function main loop
    for (size_t block_num = 0; block_num < 64; ++block_num) {
        const auto s1 =
            right_rotate(e, 6) ^ right_rotate(e, 11) ^ right_rotate(e, 25);
        const auto ch = (e & f) ^ (~e & g);
        const auto temp1 =
            h + s1 + ch + round_constants[block_num] + blocks[block_num];
        const auto s0 =
            right_rotate(a, 2) ^ right_rotate(a, 13) ^ right_rotate(a, 22);
        const auto maj = (a & b) ^ (a & c) ^ (b & c);
        const auto temp2 = s0 + maj;
 
        h = g;
        g = f;
        f = e;
        e = d + temp1;
        d = c;
        c = b;
        b = a;
        a = temp1 + temp2;
    }
 
    // Update hash values
    hash[0] += a;
    hash[1] += b;
    hash[2] += c;
    hash[3] += d;
    hash[4] += e;
    hash[5] += f;
    hash[6] += g;
    hash[7] += h;
}

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Member Data Documentation

hash

std::array<uint32_t, 8> hashing::sha256::Hash::hash

private

Initial value:

= {0x6A09E667, 0xBB67AE85, 0x3C6EF372,
                                    0xA54FF53A, 0x510E527F, 0x9B05688C,
                                    0x1F83D9AB, 0x5BE0CD19}

                                 {0x6A09E667, 0xBB67AE85, 0x3C6EF372,
                                    0xA54FF53A, 0x510E527F, 0x9B05688C,
                                    0x1F83D9AB, 0x5BE0CD19};

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The documentation for this class was generated from the following file:

• hashing/sha256.cpp