diff options
Diffstat (limited to 'vendor/golang.org/x/crypto/sha3/sha3_s390x.go')
-rw-r--r-- | vendor/golang.org/x/crypto/sha3/sha3_s390x.go | 285 |
1 files changed, 285 insertions, 0 deletions
diff --git a/vendor/golang.org/x/crypto/sha3/sha3_s390x.go b/vendor/golang.org/x/crypto/sha3/sha3_s390x.go new file mode 100644 index 0000000..4fcfc92 --- /dev/null +++ b/vendor/golang.org/x/crypto/sha3/sha3_s390x.go @@ -0,0 +1,285 @@ +// Copyright 2017 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. + +//go:build gc && !purego +// +build gc,!purego + +package sha3 + +// This file contains code for using the 'compute intermediate +// message digest' (KIMD) and 'compute last message digest' (KLMD) +// instructions to compute SHA-3 and SHAKE hashes on IBM Z. + +import ( + "hash" + + "golang.org/x/sys/cpu" +) + +// codes represent 7-bit KIMD/KLMD function codes as defined in +// the Principles of Operation. +type code uint64 + +const ( + // function codes for KIMD/KLMD + sha3_224 code = 32 + sha3_256 = 33 + sha3_384 = 34 + sha3_512 = 35 + shake_128 = 36 + shake_256 = 37 + nopad = 0x100 +) + +// kimd is a wrapper for the 'compute intermediate message digest' instruction. +// src must be a multiple of the rate for the given function code. +//go:noescape +func kimd(function code, chain *[200]byte, src []byte) + +// klmd is a wrapper for the 'compute last message digest' instruction. +// src padding is handled by the instruction. +//go:noescape +func klmd(function code, chain *[200]byte, dst, src []byte) + +type asmState struct { + a [200]byte // 1600 bit state + buf []byte // care must be taken to ensure cap(buf) is a multiple of rate + rate int // equivalent to block size + storage [3072]byte // underlying storage for buf + outputLen int // output length if fixed, 0 if not + function code // KIMD/KLMD function code + state spongeDirection // whether the sponge is absorbing or squeezing +} + +func newAsmState(function code) *asmState { + var s asmState + s.function = function + switch function { + case sha3_224: + s.rate = 144 + s.outputLen = 28 + case sha3_256: + s.rate = 136 + s.outputLen = 32 + case sha3_384: + s.rate = 104 + s.outputLen = 48 + case sha3_512: + s.rate = 72 + s.outputLen = 64 + case shake_128: + s.rate = 168 + case shake_256: + s.rate = 136 + default: + panic("sha3: unrecognized function code") + } + + // limit s.buf size to a multiple of s.rate + s.resetBuf() + return &s +} + +func (s *asmState) clone() *asmState { + c := *s + c.buf = c.storage[:len(s.buf):cap(s.buf)] + return &c +} + +// copyIntoBuf copies b into buf. It will panic if there is not enough space to +// store all of b. +func (s *asmState) copyIntoBuf(b []byte) { + bufLen := len(s.buf) + s.buf = s.buf[:len(s.buf)+len(b)] + copy(s.buf[bufLen:], b) +} + +// resetBuf points buf at storage, sets the length to 0 and sets cap to be a +// multiple of the rate. +func (s *asmState) resetBuf() { + max := (cap(s.storage) / s.rate) * s.rate + s.buf = s.storage[:0:max] +} + +// Write (via the embedded io.Writer interface) adds more data to the running hash. +// It never returns an error. +func (s *asmState) Write(b []byte) (int, error) { + if s.state != spongeAbsorbing { + panic("sha3: write to sponge after read") + } + length := len(b) + for len(b) > 0 { + if len(s.buf) == 0 && len(b) >= cap(s.buf) { + // Hash the data directly and push any remaining bytes + // into the buffer. + remainder := len(b) % s.rate + kimd(s.function, &s.a, b[:len(b)-remainder]) + if remainder != 0 { + s.copyIntoBuf(b[len(b)-remainder:]) + } + return length, nil + } + + if len(s.buf) == cap(s.buf) { + // flush the buffer + kimd(s.function, &s.a, s.buf) + s.buf = s.buf[:0] + } + + // copy as much as we can into the buffer + n := len(b) + if len(b) > cap(s.buf)-len(s.buf) { + n = cap(s.buf) - len(s.buf) + } + s.copyIntoBuf(b[:n]) + b = b[n:] + } + return length, nil +} + +// Read squeezes an arbitrary number of bytes from the sponge. +func (s *asmState) Read(out []byte) (n int, err error) { + n = len(out) + + // need to pad if we were absorbing + if s.state == spongeAbsorbing { + s.state = spongeSqueezing + + // write hash directly into out if possible + if len(out)%s.rate == 0 { + klmd(s.function, &s.a, out, s.buf) // len(out) may be 0 + s.buf = s.buf[:0] + return + } + + // write hash into buffer + max := cap(s.buf) + if max > len(out) { + max = (len(out)/s.rate)*s.rate + s.rate + } + klmd(s.function, &s.a, s.buf[:max], s.buf) + s.buf = s.buf[:max] + } + + for len(out) > 0 { + // flush the buffer + if len(s.buf) != 0 { + c := copy(out, s.buf) + out = out[c:] + s.buf = s.buf[c:] + continue + } + + // write hash directly into out if possible + if len(out)%s.rate == 0 { + klmd(s.function|nopad, &s.a, out, nil) + return + } + + // write hash into buffer + s.resetBuf() + if cap(s.buf) > len(out) { + s.buf = s.buf[:(len(out)/s.rate)*s.rate+s.rate] + } + klmd(s.function|nopad, &s.a, s.buf, nil) + } + return +} + +// Sum appends the current hash to b and returns the resulting slice. +// It does not change the underlying hash state. +func (s *asmState) Sum(b []byte) []byte { + if s.outputLen == 0 { + panic("sha3: cannot call Sum on SHAKE functions") + } + + // Copy the state to preserve the original. + a := s.a + + // Hash the buffer. Note that we don't clear it because we + // aren't updating the state. + klmd(s.function, &a, nil, s.buf) + return append(b, a[:s.outputLen]...) +} + +// Reset resets the Hash to its initial state. +func (s *asmState) Reset() { + for i := range s.a { + s.a[i] = 0 + } + s.resetBuf() + s.state = spongeAbsorbing +} + +// Size returns the number of bytes Sum will return. +func (s *asmState) Size() int { + return s.outputLen +} + +// BlockSize returns the hash's underlying block size. +// The Write method must be able to accept any amount +// of data, but it may operate more efficiently if all writes +// are a multiple of the block size. +func (s *asmState) BlockSize() int { + return s.rate +} + +// Clone returns a copy of the ShakeHash in its current state. +func (s *asmState) Clone() ShakeHash { + return s.clone() +} + +// new224Asm returns an assembly implementation of SHA3-224 if available, +// otherwise it returns nil. +func new224Asm() hash.Hash { + if cpu.S390X.HasSHA3 { + return newAsmState(sha3_224) + } + return nil +} + +// new256Asm returns an assembly implementation of SHA3-256 if available, +// otherwise it returns nil. +func new256Asm() hash.Hash { + if cpu.S390X.HasSHA3 { + return newAsmState(sha3_256) + } + return nil +} + +// new384Asm returns an assembly implementation of SHA3-384 if available, +// otherwise it returns nil. +func new384Asm() hash.Hash { + if cpu.S390X.HasSHA3 { + return newAsmState(sha3_384) + } + return nil +} + +// new512Asm returns an assembly implementation of SHA3-512 if available, +// otherwise it returns nil. +func new512Asm() hash.Hash { + if cpu.S390X.HasSHA3 { + return newAsmState(sha3_512) + } + return nil +} + +// newShake128Asm returns an assembly implementation of SHAKE-128 if available, +// otherwise it returns nil. +func newShake128Asm() ShakeHash { + if cpu.S390X.HasSHA3 { + return newAsmState(shake_128) + } + return nil +} + +// newShake256Asm returns an assembly implementation of SHAKE-256 if available, +// otherwise it returns nil. +func newShake256Asm() ShakeHash { + if cpu.S390X.HasSHA3 { + return newAsmState(shake_256) + } + return nil +} |