3b39edcaa1
Profiles discovered that lookups into the signature cache included an
expensive comparison to the stored `sigInfo` struct. This lookup had the
potential to be more expensive than directly verifying the signature
itself!
In addition, evictions were rather expensive because they involved
reading from /dev/urandom, or equivalent, for each eviction once the
signature cache was full as well as potentially iterating over every
item in the cache in the worst-case.
To remedy this poor performance several changes have been made:
* Change the lookup key to the fixed sized 32-byte signature hash
* Perform a full equality check only if there is a cache hit which
results in a significant speed up for both insertions and existence
checks
* Override entries in the case of a colliding hash on insert Add an
* .IsEqual() method to the Signature and PublicKey types in the
btcec package to facilitate easy equivalence testing
* Allocate the signature cache map with the max number of entries in
order to avoid unnecessary map re-sizes/allocations
* Optimize evictions from the signature cache Delete the first entry
* seen which is safe from manipulation due to
the pre image resistance of the hash function
* Double the default maximum number of entries within the signature
cache due to the reduction in the size of a cache entry
* With this eviction scheme, removals are effectively O(1)
Fixes #575.
|
||
|---|---|---|
| .. | ||
| bench_test.go | ||
| btcec.go | ||
| btcec_test.go | ||
| ciphering.go | ||
| ciphering_test.go | ||
| doc.go | ||
| example_test.go | ||
| field.go | ||
| field_test.go | ||
| genprecomps.go | ||
| gensecp256k1.go | ||
| internal_test.go | ||
| precompute.go | ||
| privkey.go | ||
| privkey_test.go | ||
| pubkey.go | ||
| pubkey_test.go | ||
| README.md | ||
| secp256k1.go | ||
| signature.go | ||
| signature_test.go | ||
btcec
[
]
(https://travis-ci.org/btcsuite/btcec) ![ISC License]
(http://img.shields.io/badge/license-ISC-blue.svg)
[
]
(http://godoc.org/github.com/btcsuite/btcd/btcec)
Package btcec implements elliptic curve cryptography needed for working with Bitcoin (secp256k1 only for now). It is designed so that it may be used with the standard crypto/ecdsa packages provided with go. A comprehensive suite of test is provided to ensure proper functionality. Package btcec was originally based on work from ThePiachu which is licensed under the same terms as Go, but it has signficantly diverged since then. The btcsuite developers original is licensed under the liberal ISC license.
Although this package was primarily written for btcd, it has intentionally been designed so it can be used as a standalone package for any projects needing to use secp256k1 elliptic curve cryptography.
Installation and Updating
$ go get -u github.com/btcsuite/btcd/btcec
Examples
-
[Sign Message] (http://godoc.org/github.com/btcsuite/btcd/btcec#example-package--SignMessage)
Demonstrates signing a message with a secp256k1 private key that is first parsed form raw bytes and serializing the generated signature. -
[Verify Signature] (http://godoc.org/github.com/btcsuite/btcd/btcec#example-package--VerifySignature)
Demonstrates verifying a secp256k1 signature against a public key that is first parsed from raw bytes. The signature is also parsed from raw bytes. -
[Encryption] (http://godoc.org/github.com/btcsuite/btcd/btcec#example-package--EncryptMessage) Demonstrates encrypting a message for a public key that is first parsed from raw bytes, then decrypting it using the corresponding private key.
-
[Decryption] (http://godoc.org/github.com/btcsuite/btcd/btcec#example-package--DecryptMessage) Demonstrates decrypting a message using a private key that is first parsed from raw bytes.
GPG Verification Key
All official release tags are signed by Conformal so users can ensure the code has not been tampered with and is coming from the btcsuite developers. To verify the signature perform the following:
-
Download the public key from the Conformal website at https://opensource.conformal.com/GIT-GPG-KEY-conformal.txt
-
Import the public key into your GPG keyring:
gpg --import GIT-GPG-KEY-conformal.txt -
Verify the release tag with the following command where
TAG_NAMEis a placeholder for the specific tag:git tag -v TAG_NAME
License
Package btcec is licensed under the copyfree ISC License except for btcec.go and btcec_test.go which is under the same license as Go.