diff options
Diffstat (limited to 'vendor/github.com/miekg/dns/vendor/golang.org/x/crypto/sha3/sha3.go')
| -rw-r--r-- | vendor/github.com/miekg/dns/vendor/golang.org/x/crypto/sha3/sha3.go | 192 |
1 files changed, 0 insertions, 192 deletions
diff --git a/vendor/github.com/miekg/dns/vendor/golang.org/x/crypto/sha3/sha3.go b/vendor/github.com/miekg/dns/vendor/golang.org/x/crypto/sha3/sha3.go deleted file mode 100644 index b12a35c87..000000000 --- a/vendor/github.com/miekg/dns/vendor/golang.org/x/crypto/sha3/sha3.go +++ /dev/null @@ -1,192 +0,0 @@ -// Copyright 2014 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. - -package sha3 - -// spongeDirection indicates the direction bytes are flowing through the sponge. -type spongeDirection int - -const ( - // spongeAbsorbing indicates that the sponge is absorbing input. - spongeAbsorbing spongeDirection = iota - // spongeSqueezing indicates that the sponge is being squeezed. - spongeSqueezing -) - -const ( - // maxRate is the maximum size of the internal buffer. SHAKE-256 - // currently needs the largest buffer. - maxRate = 168 -) - -type state struct { - // Generic sponge components. - a [25]uint64 // main state of the hash - buf []byte // points into storage - rate int // the number of bytes of state to use - - // dsbyte contains the "domain separation" bits and the first bit of - // the padding. Sections 6.1 and 6.2 of [1] separate the outputs of the - // SHA-3 and SHAKE functions by appending bitstrings to the message. - // Using a little-endian bit-ordering convention, these are "01" for SHA-3 - // and "1111" for SHAKE, or 00000010b and 00001111b, respectively. Then the - // padding rule from section 5.1 is applied to pad the message to a multiple - // of the rate, which involves adding a "1" bit, zero or more "0" bits, and - // a final "1" bit. We merge the first "1" bit from the padding into dsbyte, - // giving 00000110b (0x06) and 00011111b (0x1f). - // [1] http://csrc.nist.gov/publications/drafts/fips-202/fips_202_draft.pdf - // "Draft FIPS 202: SHA-3 Standard: Permutation-Based Hash and - // Extendable-Output Functions (May 2014)" - dsbyte byte - storage [maxRate]byte - - // Specific to SHA-3 and SHAKE. - outputLen int // the default output size in bytes - state spongeDirection // whether the sponge is absorbing or squeezing -} - -// BlockSize returns the rate of sponge underlying this hash function. -func (d *state) BlockSize() int { return d.rate } - -// Size returns the output size of the hash function in bytes. -func (d *state) Size() int { return d.outputLen } - -// Reset clears the internal state by zeroing the sponge state and -// the byte buffer, and setting Sponge.state to absorbing. -func (d *state) Reset() { - // Zero the permutation's state. - for i := range d.a { - d.a[i] = 0 - } - d.state = spongeAbsorbing - d.buf = d.storage[:0] -} - -func (d *state) clone() *state { - ret := *d - if ret.state == spongeAbsorbing { - ret.buf = ret.storage[:len(ret.buf)] - } else { - ret.buf = ret.storage[d.rate-cap(d.buf) : d.rate] - } - - return &ret -} - -// permute applies the KeccakF-1600 permutation. It handles -// any input-output buffering. -func (d *state) permute() { - switch d.state { - case spongeAbsorbing: - // If we're absorbing, we need to xor the input into the state - // before applying the permutation. - xorIn(d, d.buf) - d.buf = d.storage[:0] - keccakF1600(&d.a) - case spongeSqueezing: - // If we're squeezing, we need to apply the permutatin before - // copying more output. - keccakF1600(&d.a) - d.buf = d.storage[:d.rate] - copyOut(d, d.buf) - } -} - -// pads appends the domain separation bits in dsbyte, applies -// the multi-bitrate 10..1 padding rule, and permutes the state. -func (d *state) padAndPermute(dsbyte byte) { - if d.buf == nil { - d.buf = d.storage[:0] - } - // Pad with this instance's domain-separator bits. We know that there's - // at least one byte of space in d.buf because, if it were full, - // permute would have been called to empty it. dsbyte also contains the - // first one bit for the padding. See the comment in the state struct. - d.buf = append(d.buf, dsbyte) - zerosStart := len(d.buf) - d.buf = d.storage[:d.rate] - for i := zerosStart; i < d.rate; i++ { - d.buf[i] = 0 - } - // This adds the final one bit for the padding. Because of the way that - // bits are numbered from the LSB upwards, the final bit is the MSB of - // the last byte. - d.buf[d.rate-1] ^= 0x80 - // Apply the permutation - d.permute() - d.state = spongeSqueezing - d.buf = d.storage[:d.rate] - copyOut(d, d.buf) -} - -// Write absorbs more data into the hash's state. It produces an error -// if more data is written to the ShakeHash after writing -func (d *state) Write(p []byte) (written int, err error) { - if d.state != spongeAbsorbing { - panic("sha3: write to sponge after read") - } - if d.buf == nil { - d.buf = d.storage[:0] - } - written = len(p) - - for len(p) > 0 { - if len(d.buf) == 0 && len(p) >= d.rate { - // The fast path; absorb a full "rate" bytes of input and apply the permutation. - xorIn(d, p[:d.rate]) - p = p[d.rate:] - keccakF1600(&d.a) - } else { - // The slow path; buffer the input until we can fill the sponge, and then xor it in. - todo := d.rate - len(d.buf) - if todo > len(p) { - todo = len(p) - } - d.buf = append(d.buf, p[:todo]...) - p = p[todo:] - - // If the sponge is full, apply the permutation. - if len(d.buf) == d.rate { - d.permute() - } - } - } - - return -} - -// Read squeezes an arbitrary number of bytes from the sponge. -func (d *state) Read(out []byte) (n int, err error) { - // If we're still absorbing, pad and apply the permutation. - if d.state == spongeAbsorbing { - d.padAndPermute(d.dsbyte) - } - - n = len(out) - - // Now, do the squeezing. - for len(out) > 0 { - n := copy(out, d.buf) - d.buf = d.buf[n:] - out = out[n:] - - // Apply the permutation if we've squeezed the sponge dry. - if len(d.buf) == 0 { - d.permute() - } - } - - return -} - -// Sum applies padding to the hash state and then squeezes out the desired -// number of output bytes. -func (d *state) Sum(in []byte) []byte { - // Make a copy of the original hash so that caller can keep writing - // and summing. - dup := d.clone() - hash := make([]byte, dup.outputLen) - dup.Read(hash) - return append(in, hash...) -} |