PicoSHA2 - a C++ SHA256 hash generator

Introduction

PicoSHA2 is a tiny SHA256 hash generator for C++ with following properties:

header-file only
no external dependencies (only uses standard C++ libraries)
STL-friendly
licensed under MIT License

Generating SHA256 hash and hash hex string

// any STL sequantial container (vector, list, dequeue...)
std::string src_str = "The quick brown fox jumps over the lazy dog";

std::vector<unsigned char> hash(32);
picosha2::hash256(src_str.begin(), src_str.end(), hash.begin(), hash.end());

std::string hex_str = picosha2::bytes_to_hex_string(hash.begin(), hash.end());

Generating SHA256 hash and hash hex string from byte stream

picosha2::hash256_one_by_one hasher;
...
hasher.process(block.begin(), block.end());
...
hasher.finish();

std::vector<unsigned char> hash(32);
hasher.get_hash_bytes(hash.begin(), hash.end());

std::string hex_str = picosha2::get_hash_hex_string(hasher);

example/interactive_hasher.cpp has more detail information.

Generating SHA256 hash from a binary file

std::ifstream ifs("file.txt", std::ios::binary);
std::vector<unsigned char> hash(32);
picosha2::hash256(std::istreambuf_iterator<char>(ifs), std::istreambuf_iterator<char>(), hash.begin(), hash.end());

This hash256 may use less memory than reading whole of the file.

Generating SHA256 hash hex string from std::string

std::string src_str = "The quick brown fox jumps over the lazy dog";
std::string hash_hex_str;
picosha2::hash256_hex_string(src_str, hash_hex_str);
std::cout << hash_hex_str << std::endl;
//this output is "d7a8fbb307d7809469ca9abcb0082e4f8d5651e46d3cdb762d02d0bf37c9e592"

std::string src_str = "The quick brown fox jumps over the lazy dog";
std::string hash_hex_str = picosha2::hash256_hex_string(src_str);
std::cout << hash_hex_str << std::endl;
//this output is "d7a8fbb307d7809469ca9abcb0082e4f8d5651e46d3cdb762d02d0bf37c9e592"

std::string src_str = "The quick brown fox jumps over the lazy dog.";//add '.'
std::string hash_hex_str = picosha2::hash256_hex_string(src_str.begin(), src_str.end());
std::cout << hash_hex_str << std::endl;
//this output is "ef537f25c895bfa782526529a9b63d97aa631564d5d789c2b765448c8635fb6c"

Generating SHA256 hash hex string from byte sequence

std::vector<unsigned char> src_vect(...);
std::string hash_hex_str;
picosha2::hash256_hex_string(src_vect, hash_hex_str);

std::vector<unsigned char> src_vect(...);
std::string hash_hex_str = picosha2::hash256_hex_string(src_vect);

unsigned char src_c_array[32] = {...};
std::string hash_hex_str;
picosha2::hash256_hex_string(src_c_array, src_c_array+32, hash_hex_str);

unsigned char src_c_array[32] = {...};
std::string hash_hex_str = picosha2::hash256_hex_string(src_c_array, src_c_array+32);

Generating SHA256 hash byte sequence from STL sequantial container

//any STL sequantial container (vector, list, dequeue...)
std::string src_str = "The quick brown fox jumps over the lazy dog";

//any STL sequantial containers (vector, list, dequeue...)
std::vector<unsigned char> hash(32); 
picosha2::hash256(src_str, hash);

//any STL sequantial container (vector, list, dequeue...)
std::string src_str = "The quick brown fox jumps over the lazy dog";

//any STL sequantial containers (vector, list, dequeue...)
std::vector<unsigned char> hash(32);
picosha2::hash256(src_str.begin(), src_str.end(), hash);

std::string src_str = "The quick brown fox jumps over the lazy dog";
unsigned char hash_byte_c_array[32]; 
picosha2::hash256(src_str, hash_byte_c_array, hash_byte_c_array+32);

std::string src_str = "The quick brown fox jumps over the lazy dog";
std::vector<unsigned char> hash(32);
picosha2::hash256(src_str.begin(), src_str.end(), hash.begin(), hash.end());

Ozmitter / PicoSHA2