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Diffstat (limited to 'src/crypto/elliptic/internal/fiat/p521.go')
-rw-r--r-- | src/crypto/elliptic/internal/fiat/p521.go | 135 |
1 files changed, 135 insertions, 0 deletions
diff --git a/src/crypto/elliptic/internal/fiat/p521.go b/src/crypto/elliptic/internal/fiat/p521.go new file mode 100644 index 0000000..3d12117 --- /dev/null +++ b/src/crypto/elliptic/internal/fiat/p521.go @@ -0,0 +1,135 @@ +// Copyright 2021 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. + +// Code generated by generate.go. DO NOT EDIT. + +package fiat + +import ( + "crypto/subtle" + "errors" +) + +// P521Element is an integer modulo 2^521 - 1. +// +// The zero value is a valid zero element. +type P521Element struct { + // Values are represented internally always in the Montgomery domain, and + // converted in Bytes and SetBytes. + x p521MontgomeryDomainFieldElement +} + +const p521ElementLen = 66 + +type p521UntypedFieldElement = [9]uint64 + +// One sets e = 1, and returns e. +func (e *P521Element) One() *P521Element { + p521SetOne(&e.x) + return e +} + +// Equal returns 1 if e == t, and zero otherwise. +func (e *P521Element) Equal(t *P521Element) int { + eBytes := e.Bytes() + tBytes := t.Bytes() + return subtle.ConstantTimeCompare(eBytes, tBytes) +} + +var p521ZeroEncoding = new(P521Element).Bytes() + +// IsZero returns 1 if e == 0, and zero otherwise. +func (e *P521Element) IsZero() int { + eBytes := e.Bytes() + return subtle.ConstantTimeCompare(eBytes, p521ZeroEncoding) +} + +// Set sets e = t, and returns e. +func (e *P521Element) Set(t *P521Element) *P521Element { + e.x = t.x + return e +} + +// Bytes returns the 66-byte big-endian encoding of e. +func (e *P521Element) Bytes() []byte { + // This function is outlined to make the allocations inline in the caller + // rather than happen on the heap. + var out [p521ElementLen]byte + return e.bytes(&out) +} + +func (e *P521Element) bytes(out *[p521ElementLen]byte) []byte { + var tmp p521NonMontgomeryDomainFieldElement + p521FromMontgomery(&tmp, &e.x) + p521ToBytes(out, (*p521UntypedFieldElement)(&tmp)) + p521InvertEndianness(out[:]) + return out[:] +} + +// p521MinusOneEncoding is the encoding of -1 mod p, so p - 1, the +// highest canonical encoding. It is used by SetBytes to check for non-canonical +// encodings such as p + k, 2p + k, etc. +var p521MinusOneEncoding = new(P521Element).Sub( + new(P521Element), new(P521Element).One()).Bytes() + +// SetBytes sets e = v, where v is a big-endian 66-byte encoding, and returns e. +// If v is not 66 bytes or it encodes a value higher than 2^521 - 1, +// SetBytes returns nil and an error, and e is unchanged. +func (e *P521Element) SetBytes(v []byte) (*P521Element, error) { + if len(v) != p521ElementLen { + return nil, errors.New("invalid P521Element encoding") + } + for i := range v { + if v[i] < p521MinusOneEncoding[i] { + break + } + if v[i] > p521MinusOneEncoding[i] { + return nil, errors.New("invalid P521Element encoding") + } + } + var in [p521ElementLen]byte + copy(in[:], v) + p521InvertEndianness(in[:]) + var tmp p521NonMontgomeryDomainFieldElement + p521FromBytes((*p521UntypedFieldElement)(&tmp), &in) + p521ToMontgomery(&e.x, &tmp) + return e, nil +} + +// Add sets e = t1 + t2, and returns e. +func (e *P521Element) Add(t1, t2 *P521Element) *P521Element { + p521Add(&e.x, &t1.x, &t2.x) + return e +} + +// Sub sets e = t1 - t2, and returns e. +func (e *P521Element) Sub(t1, t2 *P521Element) *P521Element { + p521Sub(&e.x, &t1.x, &t2.x) + return e +} + +// Mul sets e = t1 * t2, and returns e. +func (e *P521Element) Mul(t1, t2 *P521Element) *P521Element { + p521Mul(&e.x, &t1.x, &t2.x) + return e +} + +// Square sets e = t * t, and returns e. +func (e *P521Element) Square(t *P521Element) *P521Element { + p521Square(&e.x, &t.x) + return e +} + +// Select sets v to a if cond == 1, and to b if cond == 0. +func (v *P521Element) Select(a, b *P521Element, cond int) *P521Element { + p521Selectznz((*p521UntypedFieldElement)(&v.x), p521Uint1(cond), + (*p521UntypedFieldElement)(&b.x), (*p521UntypedFieldElement)(&a.x)) + return v +} + +func p521InvertEndianness(v []byte) { + for i := 0; i < len(v)/2; i++ { + v[i], v[len(v)-1-i] = v[len(v)-1-i], v[i] + } +} |