| // 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. |
| |
| //go:build ignore |
| |
| package main |
| |
| import ( |
| "bytes" |
| "go/format" |
| "io" |
| "log" |
| "os" |
| "os/exec" |
| "text/template" |
| ) |
| |
| var curves = []struct { |
| Element string |
| Prime string |
| Prefix string |
| FiatType string |
| BytesLen int |
| }{ |
| { |
| Element: "P224Element", |
| Prime: "2^224 - 2^96 + 1", |
| Prefix: "p224", |
| FiatType: "[4]uint64", |
| BytesLen: 28, |
| }, |
| // The 32-bit pure Go P-256 in crypto/elliptic is still faster than the |
| // autogenerated code here, regrettably. |
| // { |
| // Element: "P256Element", |
| // Prime: "2^256 - 2^224 + 2^192 + 2^96 - 1", |
| // Prefix: "p256", |
| // FiatType: "[4]uint64", |
| // BytesLen: 32, |
| // }, |
| { |
| Element: "P384Element", |
| Prime: "2^384 - 2^128 - 2^96 + 2^32 - 1", |
| Prefix: "p384", |
| FiatType: "[6]uint64", |
| BytesLen: 48, |
| }, |
| // Note that unsaturated_solinas would be about 2x faster than |
| // word_by_word_montgomery for P-521, but this curve is used rarely enough |
| // that it's not worth carrying unsaturated_solinas support for it. |
| { |
| Element: "P521Element", |
| Prime: "2^521 - 1", |
| Prefix: "p521", |
| FiatType: "[9]uint64", |
| BytesLen: 66, |
| }, |
| } |
| |
| func main() { |
| t := template.Must(template.New("montgomery").Parse(tmplWrapper)) |
| |
| tmplAddchainFile, err := os.CreateTemp("", "addchain-template") |
| if err != nil { |
| log.Fatal(err) |
| } |
| defer os.Remove(tmplAddchainFile.Name()) |
| if _, err := io.WriteString(tmplAddchainFile, tmplAddchain); err != nil { |
| log.Fatal(err) |
| } |
| if err := tmplAddchainFile.Close(); err != nil { |
| log.Fatal(err) |
| } |
| |
| for _, c := range curves { |
| log.Printf("Generating %s.go...", c.Prefix) |
| f, err := os.Create(c.Prefix + ".go") |
| if err != nil { |
| log.Fatal(err) |
| } |
| if err := t.Execute(f, c); err != nil { |
| log.Fatal(err) |
| } |
| if err := f.Close(); err != nil { |
| log.Fatal(err) |
| } |
| |
| log.Printf("Generating %s_fiat64.go...", c.Prefix) |
| cmd := exec.Command("docker", "run", "--rm", "--entrypoint", "word_by_word_montgomery", |
| "fiat-crypto:v0.0.9", "--lang", "Go", "--no-wide-int", "--cmovznz-by-mul", |
| "--relax-primitive-carry-to-bitwidth", "32,64", "--internal-static", |
| "--public-function-case", "camelCase", "--public-type-case", "camelCase", |
| "--private-function-case", "camelCase", "--private-type-case", "camelCase", |
| "--doc-text-before-function-name", "", "--doc-newline-before-package-declaration", |
| "--doc-prepend-header", "Code generated by Fiat Cryptography. DO NOT EDIT.", |
| "--package-name", "fiat", "--no-prefix-fiat", c.Prefix, "64", c.Prime, |
| "mul", "square", "add", "sub", "one", "from_montgomery", "to_montgomery", |
| "selectznz", "to_bytes", "from_bytes") |
| cmd.Stderr = os.Stderr |
| out, err := cmd.Output() |
| if err != nil { |
| log.Fatal(err) |
| } |
| out, err = format.Source(out) |
| if err != nil { |
| log.Fatal(err) |
| } |
| if err := os.WriteFile(c.Prefix+"_fiat64.go", out, 0644); err != nil { |
| log.Fatal(err) |
| } |
| |
| log.Printf("Generating %s_invert.go...", c.Prefix) |
| f, err = os.CreateTemp("", "addchain-"+c.Prefix) |
| if err != nil { |
| log.Fatal(err) |
| } |
| defer os.Remove(f.Name()) |
| cmd = exec.Command("addchain", "search", c.Prime+" - 2") |
| cmd.Stderr = os.Stderr |
| cmd.Stdout = f |
| if err := cmd.Run(); err != nil { |
| log.Fatal(err) |
| } |
| if err := f.Close(); err != nil { |
| log.Fatal(err) |
| } |
| cmd = exec.Command("addchain", "gen", "-tmpl", tmplAddchainFile.Name(), f.Name()) |
| cmd.Stderr = os.Stderr |
| out, err = cmd.Output() |
| if err != nil { |
| log.Fatal(err) |
| } |
| out = bytes.Replace(out, []byte("Element"), []byte(c.Element), -1) |
| out, err = format.Source(out) |
| if err != nil { |
| log.Fatal(err) |
| } |
| if err := os.WriteFile(c.Prefix+"_invert.go", out, 0644); err != nil { |
| log.Fatal(err) |
| } |
| } |
| } |
| |
| const tmplWrapper = `// 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" |
| ) |
| |
| // {{ .Element }} is an integer modulo {{ .Prime }}. |
| // |
| // The zero value is a valid zero element. |
| type {{ .Element }} struct { |
| // Values are represented internally always in the Montgomery domain, and |
| // converted in Bytes and SetBytes. |
| x {{ .Prefix }}MontgomeryDomainFieldElement |
| } |
| |
| const {{ .Prefix }}ElementLen = {{ .BytesLen }} |
| |
| type {{ .Prefix }}UntypedFieldElement = {{ .FiatType }} |
| |
| // One sets e = 1, and returns e. |
| func (e *{{ .Element }}) One() *{{ .Element }} { |
| {{ .Prefix }}SetOne(&e.x) |
| return e |
| } |
| |
| // Equal returns 1 if e == t, and zero otherwise. |
| func (e *{{ .Element }}) Equal(t *{{ .Element }}) int { |
| eBytes := e.Bytes() |
| tBytes := t.Bytes() |
| return subtle.ConstantTimeCompare(eBytes, tBytes) |
| } |
| |
| var {{ .Prefix }}ZeroEncoding = new({{ .Element }}).Bytes() |
| |
| // IsZero returns 1 if e == 0, and zero otherwise. |
| func (e *{{ .Element }}) IsZero() int { |
| eBytes := e.Bytes() |
| return subtle.ConstantTimeCompare(eBytes, {{ .Prefix }}ZeroEncoding) |
| } |
| |
| // Set sets e = t, and returns e. |
| func (e *{{ .Element }}) Set(t *{{ .Element }}) *{{ .Element }} { |
| e.x = t.x |
| return e |
| } |
| |
| // Bytes returns the {{ .BytesLen }}-byte big-endian encoding of e. |
| func (e *{{ .Element }}) Bytes() []byte { |
| // This function is outlined to make the allocations inline in the caller |
| // rather than happen on the heap. |
| var out [{{ .Prefix }}ElementLen]byte |
| return e.bytes(&out) |
| } |
| |
| func (e *{{ .Element }}) bytes(out *[{{ .Prefix }}ElementLen]byte) []byte { |
| var tmp {{ .Prefix }}NonMontgomeryDomainFieldElement |
| {{ .Prefix }}FromMontgomery(&tmp, &e.x) |
| {{ .Prefix }}ToBytes(out, (*{{ .Prefix }}UntypedFieldElement)(&tmp)) |
| {{ .Prefix }}InvertEndianness(out[:]) |
| return out[:] |
| } |
| |
| // {{ .Prefix }}MinusOneEncoding 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 {{ .Prefix }}MinusOneEncoding = new({{ .Element }}).Sub( |
| new({{ .Element }}), new({{ .Element }}).One()).Bytes() |
| |
| // SetBytes sets e = v, where v is a big-endian {{ .BytesLen }}-byte encoding, and returns e. |
| // If v is not {{ .BytesLen }} bytes or it encodes a value higher than {{ .Prime }}, |
| // SetBytes returns nil and an error, and e is unchanged. |
| func (e *{{ .Element }}) SetBytes(v []byte) (*{{ .Element }}, error) { |
| if len(v) != {{ .Prefix }}ElementLen { |
| return nil, errors.New("invalid {{ .Element }} encoding") |
| } |
| for i := range v { |
| if v[i] < {{ .Prefix }}MinusOneEncoding[i] { |
| break |
| } |
| if v[i] > {{ .Prefix }}MinusOneEncoding[i] { |
| return nil, errors.New("invalid {{ .Element }} encoding") |
| } |
| } |
| var in [{{ .Prefix }}ElementLen]byte |
| copy(in[:], v) |
| {{ .Prefix }}InvertEndianness(in[:]) |
| var tmp {{ .Prefix }}NonMontgomeryDomainFieldElement |
| {{ .Prefix }}FromBytes((*{{ .Prefix }}UntypedFieldElement)(&tmp), &in) |
| {{ .Prefix }}ToMontgomery(&e.x, &tmp) |
| return e, nil |
| } |
| |
| // Add sets e = t1 + t2, and returns e. |
| func (e *{{ .Element }}) Add(t1, t2 *{{ .Element }}) *{{ .Element }} { |
| {{ .Prefix }}Add(&e.x, &t1.x, &t2.x) |
| return e |
| } |
| |
| // Sub sets e = t1 - t2, and returns e. |
| func (e *{{ .Element }}) Sub(t1, t2 *{{ .Element }}) *{{ .Element }} { |
| {{ .Prefix }}Sub(&e.x, &t1.x, &t2.x) |
| return e |
| } |
| |
| // Mul sets e = t1 * t2, and returns e. |
| func (e *{{ .Element }}) Mul(t1, t2 *{{ .Element }}) *{{ .Element }} { |
| {{ .Prefix }}Mul(&e.x, &t1.x, &t2.x) |
| return e |
| } |
| |
| // Square sets e = t * t, and returns e. |
| func (e *{{ .Element }}) Square(t *{{ .Element }}) *{{ .Element }} { |
| {{ .Prefix }}Square(&e.x, &t.x) |
| return e |
| } |
| |
| // Select sets v to a if cond == 1, and to b if cond == 0. |
| func (v *{{ .Element }}) Select(a, b *{{ .Element }}, cond int) *{{ .Element }} { |
| {{ .Prefix }}Selectznz((*{{ .Prefix }}UntypedFieldElement)(&v.x), {{ .Prefix }}Uint1(cond), |
| (*{{ .Prefix }}UntypedFieldElement)(&b.x), (*{{ .Prefix }}UntypedFieldElement)(&a.x)) |
| return v |
| } |
| |
| func {{ .Prefix }}InvertEndianness(v []byte) { |
| for i := 0; i < len(v)/2; i++ { |
| v[i], v[len(v)-1-i] = v[len(v)-1-i], v[i] |
| } |
| } |
| ` |
| |
| const tmplAddchain = `// 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 {{ .Meta.Name }}. DO NOT EDIT. |
| |
| package fiat |
| |
| // Invert sets e = 1/x, and returns e. |
| // |
| // If x == 0, Invert returns e = 0. |
| func (e *Element) Invert(x *Element) *Element { |
| // Inversion is implemented as exponentiation with exponent p − 2. |
| // The sequence of {{ .Ops.Adds }} multiplications and {{ .Ops.Doubles }} squarings is derived from the |
| // following addition chain generated with {{ .Meta.Module }} {{ .Meta.ReleaseTag }}. |
| // |
| {{- range lines (format .Script) }} |
| // {{ . }} |
| {{- end }} |
| // |
| |
| var z = new(Element).Set(e) |
| {{- range .Program.Temporaries }} |
| var {{ . }} = new(Element) |
| {{- end }} |
| {{ range $i := .Program.Instructions -}} |
| {{- with add $i.Op }} |
| {{ $i.Output }}.Mul({{ .X }}, {{ .Y }}) |
| {{- end -}} |
| |
| {{- with double $i.Op }} |
| {{ $i.Output }}.Square({{ .X }}) |
| {{- end -}} |
| |
| {{- with shift $i.Op -}} |
| {{- $first := 0 -}} |
| {{- if ne $i.Output.Identifier .X.Identifier }} |
| {{ $i.Output }}.Square({{ .X }}) |
| {{- $first = 1 -}} |
| {{- end }} |
| for s := {{ $first }}; s < {{ .S }}; s++ { |
| {{ $i.Output }}.Square({{ $i.Output }}) |
| } |
| {{- end -}} |
| {{- end }} |
| |
| return e.Set(z) |
| } |
| ` |