diff options
Diffstat (limited to 'vendor/github.com/miekg/dns/vendor/golang.org/x/crypto/hkdf')
3 files changed, 506 insertions, 0 deletions
diff --git a/vendor/github.com/miekg/dns/vendor/golang.org/x/crypto/hkdf/example_test.go b/vendor/github.com/miekg/dns/vendor/golang.org/x/crypto/hkdf/example_test.go new file mode 100644 index 000000000..df8439512 --- /dev/null +++ b/vendor/github.com/miekg/dns/vendor/golang.org/x/crypto/hkdf/example_test.go @@ -0,0 +1,61 @@ +// 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 hkdf_test + +import ( + "bytes" + "crypto/rand" + "crypto/sha256" + "fmt" + "golang.org/x/crypto/hkdf" + "io" +) + +// Usage example that expands one master key into three other cryptographically +// secure keys. +func Example_usage() { + // Underlying hash function to use + hash := sha256.New + + // Cryptographically secure master key. + master := []byte{0x00, 0x01, 0x02, 0x03} // i.e. NOT this. + + // Non secret salt, optional (can be nil) + // Recommended: hash-length sized random + salt := make([]byte, hash().Size()) + n, err := io.ReadFull(rand.Reader, salt) + if n != len(salt) || err != nil { + fmt.Println("error:", err) + return + } + + // Non secret context specific info, optional (can be nil). + // Note, independent from the master key. + info := []byte{0x03, 0x14, 0x15, 0x92, 0x65} + + // Create the key derivation function + hkdf := hkdf.New(hash, master, salt, info) + + // Generate the required keys + keys := make([][]byte, 3) + for i := 0; i < len(keys); i++ { + keys[i] = make([]byte, 24) + n, err := io.ReadFull(hkdf, keys[i]) + if n != len(keys[i]) || err != nil { + fmt.Println("error:", err) + return + } + } + + // Keys should contain 192 bit random keys + for i := 1; i <= len(keys); i++ { + fmt.Printf("Key #%d: %v\n", i, !bytes.Equal(keys[i-1], make([]byte, 24))) + } + + // Output: + // Key #1: true + // Key #2: true + // Key #3: true +} diff --git a/vendor/github.com/miekg/dns/vendor/golang.org/x/crypto/hkdf/hkdf.go b/vendor/github.com/miekg/dns/vendor/golang.org/x/crypto/hkdf/hkdf.go new file mode 100644 index 000000000..5bc246355 --- /dev/null +++ b/vendor/github.com/miekg/dns/vendor/golang.org/x/crypto/hkdf/hkdf.go @@ -0,0 +1,75 @@ +// 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 hkdf implements the HMAC-based Extract-and-Expand Key Derivation +// Function (HKDF) as defined in RFC 5869. +// +// HKDF is a cryptographic key derivation function (KDF) with the goal of +// expanding limited input keying material into one or more cryptographically +// strong secret keys. +// +// RFC 5869: https://tools.ietf.org/html/rfc5869 +package hkdf // import "golang.org/x/crypto/hkdf" + +import ( + "crypto/hmac" + "errors" + "hash" + "io" +) + +type hkdf struct { + expander hash.Hash + size int + + info []byte + counter byte + + prev []byte + cache []byte +} + +func (f *hkdf) Read(p []byte) (int, error) { + // Check whether enough data can be generated + need := len(p) + remains := len(f.cache) + int(255-f.counter+1)*f.size + if remains < need { + return 0, errors.New("hkdf: entropy limit reached") + } + // Read from the cache, if enough data is present + n := copy(p, f.cache) + p = p[n:] + + // Fill the buffer + for len(p) > 0 { + f.expander.Reset() + f.expander.Write(f.prev) + f.expander.Write(f.info) + f.expander.Write([]byte{f.counter}) + f.prev = f.expander.Sum(f.prev[:0]) + f.counter++ + + // Copy the new batch into p + f.cache = f.prev + n = copy(p, f.cache) + p = p[n:] + } + // Save leftovers for next run + f.cache = f.cache[n:] + + return need, nil +} + +// New returns a new HKDF using the given hash, the secret keying material to expand +// and optional salt and info fields. +func New(hash func() hash.Hash, secret, salt, info []byte) io.Reader { + if salt == nil { + salt = make([]byte, hash().Size()) + } + extractor := hmac.New(hash, salt) + extractor.Write(secret) + prk := extractor.Sum(nil) + + return &hkdf{hmac.New(hash, prk), extractor.Size(), info, 1, nil, nil} +} diff --git a/vendor/github.com/miekg/dns/vendor/golang.org/x/crypto/hkdf/hkdf_test.go b/vendor/github.com/miekg/dns/vendor/golang.org/x/crypto/hkdf/hkdf_test.go new file mode 100644 index 000000000..cee659bcd --- /dev/null +++ b/vendor/github.com/miekg/dns/vendor/golang.org/x/crypto/hkdf/hkdf_test.go @@ -0,0 +1,370 @@ +// 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 hkdf + +import ( + "bytes" + "crypto/md5" + "crypto/sha1" + "crypto/sha256" + "crypto/sha512" + "hash" + "io" + "testing" +) + +type hkdfTest struct { + hash func() hash.Hash + master []byte + salt []byte + info []byte + out []byte +} + +var hkdfTests = []hkdfTest{ + // Tests from RFC 5869 + { + sha256.New, + []byte{ + 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, + 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, + 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, + }, + []byte{ + 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, + 0x08, 0x09, 0x0a, 0x0b, 0x0c, + }, + []byte{ + 0xf0, 0xf1, 0xf2, 0xf3, 0xf4, 0xf5, 0xf6, 0xf7, + 0xf8, 0xf9, + }, + []byte{ + 0x3c, 0xb2, 0x5f, 0x25, 0xfa, 0xac, 0xd5, 0x7a, + 0x90, 0x43, 0x4f, 0x64, 0xd0, 0x36, 0x2f, 0x2a, + 0x2d, 0x2d, 0x0a, 0x90, 0xcf, 0x1a, 0x5a, 0x4c, + 0x5d, 0xb0, 0x2d, 0x56, 0xec, 0xc4, 0xc5, 0xbf, + 0x34, 0x00, 0x72, 0x08, 0xd5, 0xb8, 0x87, 0x18, + 0x58, 0x65, + }, + }, + { + sha256.New, + []byte{ + 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, + 0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f, + 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, + 0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f, + 0x20, 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27, + 0x28, 0x29, 0x2a, 0x2b, 0x2c, 0x2d, 0x2e, 0x2f, + 0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37, + 0x38, 0x39, 0x3a, 0x3b, 0x3c, 0x3d, 0x3e, 0x3f, + 0x40, 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47, + 0x48, 0x49, 0x4a, 0x4b, 0x4c, 0x4d, 0x4e, 0x4f, + }, + []byte{ + 0x60, 0x61, 0x62, 0x63, 0x64, 0x65, 0x66, 0x67, + 0x68, 0x69, 0x6a, 0x6b, 0x6c, 0x6d, 0x6e, 0x6f, + 0x70, 0x71, 0x72, 0x73, 0x74, 0x75, 0x76, 0x77, + 0x78, 0x79, 0x7a, 0x7b, 0x7c, 0x7d, 0x7e, 0x7f, + 0x80, 0x81, 0x82, 0x83, 0x84, 0x85, 0x86, 0x87, + 0x88, 0x89, 0x8a, 0x8b, 0x8c, 0x8d, 0x8e, 0x8f, + 0x90, 0x91, 0x92, 0x93, 0x94, 0x95, 0x96, 0x97, + 0x98, 0x99, 0x9a, 0x9b, 0x9c, 0x9d, 0x9e, 0x9f, + 0xa0, 0xa1, 0xa2, 0xa3, 0xa4, 0xa5, 0xa6, 0xa7, + 0xa8, 0xa9, 0xaa, 0xab, 0xac, 0xad, 0xae, 0xaf, + }, + []byte{ + 0xb0, 0xb1, 0xb2, 0xb3, 0xb4, 0xb5, 0xb6, 0xb7, + 0xb8, 0xb9, 0xba, 0xbb, 0xbc, 0xbd, 0xbe, 0xbf, + 0xc0, 0xc1, 0xc2, 0xc3, 0xc4, 0xc5, 0xc6, 0xc7, + 0xc8, 0xc9, 0xca, 0xcb, 0xcc, 0xcd, 0xce, 0xcf, + 0xd0, 0xd1, 0xd2, 0xd3, 0xd4, 0xd5, 0xd6, 0xd7, + 0xd8, 0xd9, 0xda, 0xdb, 0xdc, 0xdd, 0xde, 0xdf, + 0xe0, 0xe1, 0xe2, 0xe3, 0xe4, 0xe5, 0xe6, 0xe7, + 0xe8, 0xe9, 0xea, 0xeb, 0xec, 0xed, 0xee, 0xef, + 0xf0, 0xf1, 0xf2, 0xf3, 0xf4, 0xf5, 0xf6, 0xf7, + 0xf8, 0xf9, 0xfa, 0xfb, 0xfc, 0xfd, 0xfe, 0xff, + }, + []byte{ + 0xb1, 0x1e, 0x39, 0x8d, 0xc8, 0x03, 0x27, 0xa1, + 0xc8, 0xe7, 0xf7, 0x8c, 0x59, 0x6a, 0x49, 0x34, + 0x4f, 0x01, 0x2e, 0xda, 0x2d, 0x4e, 0xfa, 0xd8, + 0xa0, 0x50, 0xcc, 0x4c, 0x19, 0xaf, 0xa9, 0x7c, + 0x59, 0x04, 0x5a, 0x99, 0xca, 0xc7, 0x82, 0x72, + 0x71, 0xcb, 0x41, 0xc6, 0x5e, 0x59, 0x0e, 0x09, + 0xda, 0x32, 0x75, 0x60, 0x0c, 0x2f, 0x09, 0xb8, + 0x36, 0x77, 0x93, 0xa9, 0xac, 0xa3, 0xdb, 0x71, + 0xcc, 0x30, 0xc5, 0x81, 0x79, 0xec, 0x3e, 0x87, + 0xc1, 0x4c, 0x01, 0xd5, 0xc1, 0xf3, 0x43, 0x4f, + 0x1d, 0x87, + }, + }, + { + sha256.New, + []byte{ + 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, + 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, + 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, + }, + []byte{}, + []byte{}, + []byte{ + 0x8d, 0xa4, 0xe7, 0x75, 0xa5, 0x63, 0xc1, 0x8f, + 0x71, 0x5f, 0x80, 0x2a, 0x06, 0x3c, 0x5a, 0x31, + 0xb8, 0xa1, 0x1f, 0x5c, 0x5e, 0xe1, 0x87, 0x9e, + 0xc3, 0x45, 0x4e, 0x5f, 0x3c, 0x73, 0x8d, 0x2d, + 0x9d, 0x20, 0x13, 0x95, 0xfa, 0xa4, 0xb6, 0x1a, + 0x96, 0xc8, + }, + }, + { + sha1.New, + []byte{ + 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, + 0x0b, 0x0b, 0x0b, + }, + []byte{ + 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, + 0x08, 0x09, 0x0a, 0x0b, 0x0c, + }, + []byte{ + 0xf0, 0xf1, 0xf2, 0xf3, 0xf4, 0xf5, 0xf6, 0xf7, + 0xf8, 0xf9, + }, + []byte{ + 0x08, 0x5a, 0x01, 0xea, 0x1b, 0x10, 0xf3, 0x69, + 0x33, 0x06, 0x8b, 0x56, 0xef, 0xa5, 0xad, 0x81, + 0xa4, 0xf1, 0x4b, 0x82, 0x2f, 0x5b, 0x09, 0x15, + 0x68, 0xa9, 0xcd, 0xd4, 0xf1, 0x55, 0xfd, 0xa2, + 0xc2, 0x2e, 0x42, 0x24, 0x78, 0xd3, 0x05, 0xf3, + 0xf8, 0x96, + }, + }, + { + sha1.New, + []byte{ + 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, + 0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f, + 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, + 0x18, 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f, + 0x20, 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27, + 0x28, 0x29, 0x2a, 0x2b, 0x2c, 0x2d, 0x2e, 0x2f, + 0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37, + 0x38, 0x39, 0x3a, 0x3b, 0x3c, 0x3d, 0x3e, 0x3f, + 0x40, 0x41, 0x42, 0x43, 0x44, 0x45, 0x46, 0x47, + 0x48, 0x49, 0x4a, 0x4b, 0x4c, 0x4d, 0x4e, 0x4f, + }, + []byte{ + 0x60, 0x61, 0x62, 0x63, 0x64, 0x65, 0x66, 0x67, + 0x68, 0x69, 0x6a, 0x6b, 0x6c, 0x6d, 0x6e, 0x6f, + 0x70, 0x71, 0x72, 0x73, 0x74, 0x75, 0x76, 0x77, + 0x78, 0x79, 0x7a, 0x7b, 0x7c, 0x7d, 0x7e, 0x7f, + 0x80, 0x81, 0x82, 0x83, 0x84, 0x85, 0x86, 0x87, + 0x88, 0x89, 0x8a, 0x8b, 0x8c, 0x8d, 0x8e, 0x8f, + 0x90, 0x91, 0x92, 0x93, 0x94, 0x95, 0x96, 0x97, + 0x98, 0x99, 0x9a, 0x9b, 0x9c, 0x9d, 0x9e, 0x9f, + 0xa0, 0xa1, 0xa2, 0xa3, 0xa4, 0xa5, 0xa6, 0xa7, + 0xa8, 0xa9, 0xaa, 0xab, 0xac, 0xad, 0xae, 0xaf, + }, + []byte{ + 0xb0, 0xb1, 0xb2, 0xb3, 0xb4, 0xb5, 0xb6, 0xb7, + 0xb8, 0xb9, 0xba, 0xbb, 0xbc, 0xbd, 0xbe, 0xbf, + 0xc0, 0xc1, 0xc2, 0xc3, 0xc4, 0xc5, 0xc6, 0xc7, + 0xc8, 0xc9, 0xca, 0xcb, 0xcc, 0xcd, 0xce, 0xcf, + 0xd0, 0xd1, 0xd2, 0xd3, 0xd4, 0xd5, 0xd6, 0xd7, + 0xd8, 0xd9, 0xda, 0xdb, 0xdc, 0xdd, 0xde, 0xdf, + 0xe0, 0xe1, 0xe2, 0xe3, 0xe4, 0xe5, 0xe6, 0xe7, + 0xe8, 0xe9, 0xea, 0xeb, 0xec, 0xed, 0xee, 0xef, + 0xf0, 0xf1, 0xf2, 0xf3, 0xf4, 0xf5, 0xf6, 0xf7, + 0xf8, 0xf9, 0xfa, 0xfb, 0xfc, 0xfd, 0xfe, 0xff, + }, + []byte{ + 0x0b, 0xd7, 0x70, 0xa7, 0x4d, 0x11, 0x60, 0xf7, + 0xc9, 0xf1, 0x2c, 0xd5, 0x91, 0x2a, 0x06, 0xeb, + 0xff, 0x6a, 0xdc, 0xae, 0x89, 0x9d, 0x92, 0x19, + 0x1f, 0xe4, 0x30, 0x56, 0x73, 0xba, 0x2f, 0xfe, + 0x8f, 0xa3, 0xf1, 0xa4, 0xe5, 0xad, 0x79, 0xf3, + 0xf3, 0x34, 0xb3, 0xb2, 0x02, 0xb2, 0x17, 0x3c, + 0x48, 0x6e, 0xa3, 0x7c, 0xe3, 0xd3, 0x97, 0xed, + 0x03, 0x4c, 0x7f, 0x9d, 0xfe, 0xb1, 0x5c, 0x5e, + 0x92, 0x73, 0x36, 0xd0, 0x44, 0x1f, 0x4c, 0x43, + 0x00, 0xe2, 0xcf, 0xf0, 0xd0, 0x90, 0x0b, 0x52, + 0xd3, 0xb4, + }, + }, + { + sha1.New, + []byte{ + 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, + 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, + 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, 0x0b, + }, + []byte{}, + []byte{}, + []byte{ + 0x0a, 0xc1, 0xaf, 0x70, 0x02, 0xb3, 0xd7, 0x61, + 0xd1, 0xe5, 0x52, 0x98, 0xda, 0x9d, 0x05, 0x06, + 0xb9, 0xae, 0x52, 0x05, 0x72, 0x20, 0xa3, 0x06, + 0xe0, 0x7b, 0x6b, 0x87, 0xe8, 0xdf, 0x21, 0xd0, + 0xea, 0x00, 0x03, 0x3d, 0xe0, 0x39, 0x84, 0xd3, + 0x49, 0x18, + }, + }, + { + sha1.New, + []byte{ + 0x0c, 0x0c, 0x0c, 0x0c, 0x0c, 0x0c, 0x0c, 0x0c, + 0x0c, 0x0c, 0x0c, 0x0c, 0x0c, 0x0c, 0x0c, 0x0c, + 0x0c, 0x0c, 0x0c, 0x0c, 0x0c, 0x0c, + }, + nil, + []byte{}, + []byte{ + 0x2c, 0x91, 0x11, 0x72, 0x04, 0xd7, 0x45, 0xf3, + 0x50, 0x0d, 0x63, 0x6a, 0x62, 0xf6, 0x4f, 0x0a, + 0xb3, 0xba, 0xe5, 0x48, 0xaa, 0x53, 0xd4, 0x23, + 0xb0, 0xd1, 0xf2, 0x7e, 0xbb, 0xa6, 0xf5, 0xe5, + 0x67, 0x3a, 0x08, 0x1d, 0x70, 0xcc, 0xe7, 0xac, + 0xfc, 0x48, + }, + }, +} + +func TestHKDF(t *testing.T) { + for i, tt := range hkdfTests { + hkdf := New(tt.hash, tt.master, tt.salt, tt.info) + out := make([]byte, len(tt.out)) + + n, err := io.ReadFull(hkdf, out) + if n != len(tt.out) || err != nil { + t.Errorf("test %d: not enough output bytes: %d.", i, n) + } + + if !bytes.Equal(out, tt.out) { + t.Errorf("test %d: incorrect output: have %v, need %v.", i, out, tt.out) + } + } +} + +func TestHKDFMultiRead(t *testing.T) { + for i, tt := range hkdfTests { + hkdf := New(tt.hash, tt.master, tt.salt, tt.info) + out := make([]byte, len(tt.out)) + + for b := 0; b < len(tt.out); b++ { + n, err := io.ReadFull(hkdf, out[b:b+1]) + if n != 1 || err != nil { + t.Errorf("test %d.%d: not enough output bytes: have %d, need %d .", i, b, n, len(tt.out)) + } + } + + if !bytes.Equal(out, tt.out) { + t.Errorf("test %d: incorrect output: have %v, need %v.", i, out, tt.out) + } + } +} + +func TestHKDFLimit(t *testing.T) { + hash := sha1.New + master := []byte{0x00, 0x01, 0x02, 0x03} + info := []byte{} + + hkdf := New(hash, master, nil, info) + limit := hash().Size() * 255 + out := make([]byte, limit) + + // The maximum output bytes should be extractable + n, err := io.ReadFull(hkdf, out) + if n != limit || err != nil { + t.Errorf("not enough output bytes: %d, %v.", n, err) + } + + // Reading one more should fail + n, err = io.ReadFull(hkdf, make([]byte, 1)) + if n > 0 || err == nil { + t.Errorf("key expansion overflowed: n = %d, err = %v", n, err) + } +} + +func Benchmark16ByteMD5Single(b *testing.B) { + benchmarkHKDFSingle(md5.New, 16, b) +} + +func Benchmark20ByteSHA1Single(b *testing.B) { + benchmarkHKDFSingle(sha1.New, 20, b) +} + +func Benchmark32ByteSHA256Single(b *testing.B) { + benchmarkHKDFSingle(sha256.New, 32, b) +} + +func Benchmark64ByteSHA512Single(b *testing.B) { + benchmarkHKDFSingle(sha512.New, 64, b) +} + +func Benchmark8ByteMD5Stream(b *testing.B) { + benchmarkHKDFStream(md5.New, 8, b) +} + +func Benchmark16ByteMD5Stream(b *testing.B) { + benchmarkHKDFStream(md5.New, 16, b) +} + +func Benchmark8ByteSHA1Stream(b *testing.B) { + benchmarkHKDFStream(sha1.New, 8, b) +} + +func Benchmark20ByteSHA1Stream(b *testing.B) { + benchmarkHKDFStream(sha1.New, 20, b) +} + +func Benchmark8ByteSHA256Stream(b *testing.B) { + benchmarkHKDFStream(sha256.New, 8, b) +} + +func Benchmark32ByteSHA256Stream(b *testing.B) { + benchmarkHKDFStream(sha256.New, 32, b) +} + +func Benchmark8ByteSHA512Stream(b *testing.B) { + benchmarkHKDFStream(sha512.New, 8, b) +} + +func Benchmark64ByteSHA512Stream(b *testing.B) { + benchmarkHKDFStream(sha512.New, 64, b) +} + +func benchmarkHKDFSingle(hasher func() hash.Hash, block int, b *testing.B) { + master := []byte{0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07} + salt := []byte{0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17} + info := []byte{0x20, 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27} + out := make([]byte, block) + + b.SetBytes(int64(block)) + b.ResetTimer() + + for i := 0; i < b.N; i++ { + hkdf := New(hasher, master, salt, info) + io.ReadFull(hkdf, out) + } +} + +func benchmarkHKDFStream(hasher func() hash.Hash, block int, b *testing.B) { + master := []byte{0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07} + salt := []byte{0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17} + info := []byte{0x20, 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27} + out := make([]byte, block) + + b.SetBytes(int64(block)) + b.ResetTimer() + + hkdf := New(hasher, master, salt, info) + for i := 0; i < b.N; i++ { + _, err := io.ReadFull(hkdf, out) + if err != nil { + hkdf = New(hasher, master, salt, info) + i-- + } + } +} |