jbenet / hashpipe

hashpipe - pipe iff the hash matches

hashpipe - pipe iff the hash matches

hashpipe helps you venture into the unknown. It reads from stdin, checks the hash of the content, and outputs it IF AND ONLY IF it matches the provided hash checksum. This makes executing things a teensy bit safer, as it requires compromising more communication channels.

Example

> echo "hello" | multihash
QmUJPTFZnR2CPGAzmfdYPghgrFtYFB6pf1BqMvqfiPDam8
> echo "hello" | hashpipe QmUJPTFZnR2CPGAzmfdYPghgrFtYFB6pf1BqMvqfiPDam8
hello
> echo "goodbye" | hashpipe QmUJPTFZnR2CPGAzmfdYPghgrFtYFB6pf1BqMvqfiPDam8
error: multihash checksums did not match

Use Case

If you tell people to pipe things directly into the shell... Don't do that. If you're going to, at least provide them a hash to ensure that man-in-the-middle attacks or compromised CDNs do not hurt your users.

curl http://you.shouldnt.be/doing/this | hashpipe Qmepk1VCHpjyCmWeh61vyDKsWfKymyrBQLcmUpXUdUd3yM | sh

Hashes Supported

hashpipe uses multihash, a self-describing hash function. It supports all the hashes in go-multihash:

• sha1
• sha2-256
• sha2-512
• sha3-256
• sha3-512
• add the one you need

Install

• From source:

  go get github.com/jbenet/hashpipe
  

• Pre-built binaries: https://gobuilder.me/github.com/jbenet/hashpipe

Usage

> hashpipe -h
usage: hashpipe [MULTIHASH] <[FILE] >[FILE]

    cat untrustedFile | hashpipe <expected-checksum> | trustedContext

hashpipe - boldly journey into the unknown.

It reads from stdin, checks the hash of the content, and outputs it IF AND
ONLY IF it matches the provided hash checksum. This makes executing things
a bit safer, as it requires compromising more communication channels. On
error, hashpipe returns a non-zero error code, failing pipelines.

OPTIONS
  -a="sha2-256": one of: sha1, sha2-256, sha2-512, sha3 (shorthand)
  -algorithm="sha2-256": one of: sha1, sha2-256, sha2-512, sha3
  -e="base58": one of: raw, hex, base58, base64 (shorthand)
  -encoding="base58": one of: raw, hex, base58, base64
  -l=-1: checksums length in bits (truncate). -1 is default (shorthand)
  -length=-1: checksums length in bits (truncate). -1 is default
  -q=false: quiet output (no newline on checksum, no error text) (shorthand)
  -quiet=false: quiet output (no newline on checksum, no error text)

hashpipe's Issues

add link to multihash

• in readme
• in docs

buffer in a tmpfile

hashpipe needs to buffer all the data as the hash isn't decidable until the last bit. we could buffer on disk with a tmpfile instead of memory.

sigpipe -- hashpipe's sister

I should make a sigpipe tool that checks a signed checksum. The sig likley wont be carried in the executable, but the hash is enough:

sigpipe <hash + sig> <untrusted >trusted

need PKI though

hashpipe website links to google webfont via http

just thought i'd mention that chrome reports it blocks the webfont you're using. Accessing the very same URL via https instead of http also works (in fact, when accessing the url via http, a redirect (HSTS perhaps?) to https happens immediately anyway, same as for the github.io page itself)