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Diffstat (limited to 'libgo/go/crypto/crypto.go')
-rw-r--r-- | libgo/go/crypto/crypto.go | 73 |
1 files changed, 73 insertions, 0 deletions
diff --git a/libgo/go/crypto/crypto.go b/libgo/go/crypto/crypto.go new file mode 100644 index 0000000..be6b34a --- /dev/null +++ b/libgo/go/crypto/crypto.go @@ -0,0 +1,73 @@ +// Copyright 2011 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +// The crypto package collects common cryptographic constants. +package crypto + +import ( + "hash" +) + +// Hash identifies a cryptographic hash function that is implemented in another +// package. +type Hash uint + +const ( + MD4 Hash = 1 + iota // in package crypto/md4 + MD5 // in package crypto/md5 + SHA1 // in package crypto/sha1 + SHA224 // in package crypto/sha256 + SHA256 // in package crypto/sha256 + SHA384 // in package crypto/sha512 + SHA512 // in package crypto/sha512 + MD5SHA1 // no implementation; MD5+SHA1 used for TLS RSA + RIPEMD160 // in package crypto/ripemd160 + maxHash +) + +var digestSizes = []uint8{ + MD4: 16, + MD5: 16, + SHA1: 20, + SHA224: 28, + SHA256: 32, + SHA384: 48, + SHA512: 64, + MD5SHA1: 36, + RIPEMD160: 20, +} + +// Size returns the length, in bytes, of a digest resulting from the given hash +// function. It doesn't require that the hash function in question be linked +// into the program. +func (h Hash) Size() int { + if h > 0 && h < maxHash { + return int(digestSizes[h]) + } + panic("crypto: Size of unknown hash function") +} + +var hashes = make([]func() hash.Hash, maxHash) + +// New returns a new hash.Hash calculating the given hash function. If the +// hash function is not linked into the binary, New returns nil. +func (h Hash) New() hash.Hash { + if h > 0 && h < maxHash { + f := hashes[h] + if f != nil { + return f() + } + } + return nil +} + +// RegisterHash registers a function that returns a new instance of the given +// hash function. This is intended to be called from the init function in +// packages that implement hash functions. +func RegisterHash(h Hash, f func() hash.Hash) { + if h >= maxHash { + panic("crypto: RegisterHash of unknown hash function") + } + hashes[h] = f +} |