Base64

Base64 encoding/decoding library for C++17.

• Fast
• Header-only
• No dependencies
• Public domain (0BSD)

Installation

Copy base64.h into your project folder.

Usage

base64.h has function declarations in the beginning of the file for quick reference.

Encoding:

string s1 = to_base64("Hello, World!");

string s2 = to_base64(buf, buf_len);

Decoding:

string s1 = from_base64("SGVsbG8sIFdvcmxkIQ==");

string s2 = from_base64(buf, buf_len);

Decoding in-place:

// With data in std::string:
string s3 = "SGVsbG8sIFdvcmxkIQ==";
from_base64_inplace(s3);

// With data in void*:
size_t len = from_base64_inplace(buf, buf_len);

Note on input validation:

Validating base64 doesn't seem to be very useful, since data from a trusted source doesn't need to be validated, and data from an untrusted source must be validated after decoding anyway.

For performance reasons from_base64() doesn't validate it's input nor requires it to be validated beforehand - output data won't make much sense, but it won't impact the stability of the program.

Tests and benchmarks

100% branch coverage.

# Tests (requires doctest)
meson setup build/
meson compile -C build/ tests
./build/tests

# Tests with ASAN (requires doctest, libsanitizer)
meson setup build/ -Db_sanitize=address,undefined
meson compile -C build/ tests
./build/tests

# Benchmarks (requires benchmark)
./bench.sh

# Code coverage (requires doctest, lcov or gcov)
meson setup build_cov/ --Dcpp_eh=none Db_coverage=true
meson test -C build_cov/
ninja -C build_cov/ coverage