4d6dfc4eed
Changes since 1.0.0:
- The NEON implementation is now enabled by default on AArch64 targets.
Previously it was disabled without the "neon" Cargo feature in Rust or
the "BLAKE3_USE_NEON=1" preprocessor flag in C. This is still the case
on ARM targets other than AArch64, because of the lack of dynamic CPU
feature detection on ARM. Contributed by @rsdy.
- The previous change leads to some build incompatibilities,
particularly in C. If you build the C implementation for AArch64
targets, you now need to include blake3_neon.c, or else you'll get a
linker error like "undefined reference to `blake3_hash_many_neon'". If
you don't want the NEON implementation, you need to explicitly set
"BLAKE3_USE_NEON=0". On the Rust side, AArch64 targets now require the
C toolchain by default. build.rs includes workarounds for missing or
very old C compilers for x86, but it doesn't currently include such
workarounds for AArch64. If we hear about build breaks related to
this, we can add more workarounds as appropriate.
- C-specific Git tags ("c-0.3.7" etc.) have been removed, and all the
projects in this repo (Rust "blake3", Rust "b3sum", and the C
implementation) will continue to be versioned in lockstep for the
foreseeable future.
3.0 KiB
b3sum
A command line utility for calculating
BLAKE3 hashes, similar to
Coreutils tools like b2sum or md5sum.
b3sum 1.1.0
USAGE:
b3sum [FLAGS] [OPTIONS] [FILE]...
FLAGS:
-c, --check Reads BLAKE3 sums from the [file]s and checks them
-h, --help Prints help information
--keyed Uses the keyed mode. The secret key is read from standard
input, and it must be exactly 32 raw bytes.
--no-mmap Disables memory mapping. Currently this also disables
multithreading.
--no-names Omits filenames in the output
--quiet Skips printing OK for each successfully verified file.
Must be used with --check.
--raw Writes raw output bytes to stdout, rather than hex.
--no-names is implied. In this case, only a single
input is allowed.
-V, --version Prints version information
OPTIONS:
--derive-key <CONTEXT> Uses the key derivation mode, with the given
context string. Cannot be used with --keyed.
-l, --length <LEN> The number of output bytes, prior to hex
encoding (default 32)
--num-threads <NUM> The maximum number of threads to use. By
default, this is the number of logical cores.
If this flag is omitted, or if its value is 0,
RAYON_NUM_THREADS is also respected.
ARGS:
<FILE>... Files to hash, or checkfiles to check. When no file is given,
or when - is given, read standard input.
See also this document about how the --check flag
works.
Example
Hash the file foo.txt:
b3sum foo.txt
Time hashing a gigabyte of data, to see how fast it is:
# Create a 1 GB file.
head -c 1000000000 /dev/zero > /tmp/bigfile
# Hash it with SHA-256.
time openssl sha256 /tmp/bigfile
# Hash it with BLAKE3.
time b3sum /tmp/bigfile
Installation
Prebuilt binaries are available for Linux, Windows, and macOS (requiring
the unidentified developer
workaround)
on the releases page.
If you've installed Rust and
Cargo,
you can also build b3sum yourself with:
cargo install b3sum
On Linux for example, Cargo will put the compiled binary in
~/.cargo/bin. You might want to add that directory to your $PATH, or
rustup might have done it for you when you installed Cargo.
If you want to install directly from this directory, you can run cargo install --path .. Or you can just build with cargo build --release,
which puts the binary at ./target/release/b3sum.