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Diffstat (limited to 'libgo/go/crypto/bcrypt/bcrypt.go')
-rw-r--r-- | libgo/go/crypto/bcrypt/bcrypt.go | 282 |
1 files changed, 0 insertions, 282 deletions
diff --git a/libgo/go/crypto/bcrypt/bcrypt.go b/libgo/go/crypto/bcrypt/bcrypt.go deleted file mode 100644 index 362b2eb..0000000 --- a/libgo/go/crypto/bcrypt/bcrypt.go +++ /dev/null @@ -1,282 +0,0 @@ -// Copyright 2011 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 bcrypt implements Provos and Mazières's bcrypt adaptive hashing -// algorithm. See http://www.usenix.org/event/usenix99/provos/provos.pdf -package bcrypt - -// The code is a port of Provos and Mazières's C implementation. -import ( - "crypto/blowfish" - "crypto/rand" - "crypto/subtle" - "errors" - "fmt" - "io" - "strconv" -) - -const ( - MinCost int = 4 // the minimum allowable cost as passed in to GenerateFromPassword - MaxCost int = 31 // the maximum allowable cost as passed in to GenerateFromPassword - DefaultCost int = 10 // the cost that will actually be set if a cost below MinCost is passed into GenerateFromPassword -) - -// The error returned from CompareHashAndPassword when a password and hash do -// not match. -var MismatchedHashAndPasswordError = errors.New("crypto/bcrypt: hashedPassword is not the hash of the given password") - -// The error returned from CompareHashAndPassword when a hash is too short to -// be a bcrypt hash. -var HashTooShortError = errors.New("crypto/bcrypt: hashedSecret too short to be a bcrypted password") - -// The error returned from CompareHashAndPassword when a hash was created with -// a bcrypt algorithm newer than this implementation. -type HashVersionTooNewError byte - -func (hv HashVersionTooNewError) Error() string { - return fmt.Sprintf("crypto/bcrypt: bcrypt algorithm version '%c' requested is newer than current version '%c'", byte(hv), majorVersion) -} - -// The error returned from CompareHashAndPassword when a hash starts with something other than '$' -type InvalidHashPrefixError byte - -func (ih InvalidHashPrefixError) Error() string { - return fmt.Sprintf("crypto/bcrypt: bcrypt hashes must start with '$', but hashedSecret started with '%c'", byte(ih)) -} - -type InvalidCostError int - -func (ic InvalidCostError) Error() string { - return fmt.Sprintf("crypto/bcrypt: cost %d is outside allowed range (%d,%d)", int(ic), int(MinCost), int(MaxCost)) -} - -const ( - majorVersion = '2' - minorVersion = 'a' - maxSaltSize = 16 - maxCryptedHashSize = 23 - encodedSaltSize = 22 - encodedHashSize = 31 - minHashSize = 59 -) - -// magicCipherData is an IV for the 64 Blowfish encryption calls in -// bcrypt(). It's the string "OrpheanBeholderScryDoubt" in big-endian bytes. -var magicCipherData = []byte{ - 0x4f, 0x72, 0x70, 0x68, - 0x65, 0x61, 0x6e, 0x42, - 0x65, 0x68, 0x6f, 0x6c, - 0x64, 0x65, 0x72, 0x53, - 0x63, 0x72, 0x79, 0x44, - 0x6f, 0x75, 0x62, 0x74, -} - -type hashed struct { - hash []byte - salt []byte - cost uint32 // allowed range is MinCost to MaxCost - major byte - minor byte -} - -// GenerateFromPassword returns the bcrypt hash of the password at the given -// cost. If the cost given is less than MinCost, the cost will be set to -// MinCost, instead. Use CompareHashAndPassword, as defined in this package, -// to compare the returned hashed password with its cleartext version. -func GenerateFromPassword(password []byte, cost int) ([]byte, error) { - p, err := newFromPassword(password, cost) - if err != nil { - return nil, err - } - return p.Hash(), nil -} - -// CompareHashAndPassword compares a bcrypt hashed password with its possible -// plaintext equivalent. Note: Using bytes.Equal for this job is -// insecure. Returns nil on success, or an error on failure. -func CompareHashAndPassword(hashedPassword, password []byte) error { - p, err := newFromHash(hashedPassword) - if err != nil { - return err - } - - otherHash, err := bcrypt(password, p.cost, p.salt) - if err != nil { - return err - } - - otherP := &hashed{otherHash, p.salt, p.cost, p.major, p.minor} - if subtle.ConstantTimeCompare(p.Hash(), otherP.Hash()) == 1 { - return nil - } - - return MismatchedHashAndPasswordError -} - -func newFromPassword(password []byte, cost int) (*hashed, error) { - if cost < MinCost { - cost = DefaultCost - } - p := new(hashed) - p.major = majorVersion - p.minor = minorVersion - - err := checkCost(cost) - if err != nil { - return nil, err - } - p.cost = uint32(cost) - - unencodedSalt := make([]byte, maxSaltSize) - _, err = io.ReadFull(rand.Reader, unencodedSalt) - if err != nil { - return nil, err - } - - p.salt = base64Encode(unencodedSalt) - hash, err := bcrypt(password, p.cost, p.salt) - if err != nil { - return nil, err - } - p.hash = hash - return p, err -} - -func newFromHash(hashedSecret []byte) (*hashed, error) { - if len(hashedSecret) < minHashSize { - return nil, HashTooShortError - } - p := new(hashed) - n, err := p.decodeVersion(hashedSecret) - if err != nil { - return nil, err - } - hashedSecret = hashedSecret[n:] - n, err = p.decodeCost(hashedSecret) - if err != nil { - return nil, err - } - hashedSecret = hashedSecret[n:] - - // The "+2" is here because we'll have to append at most 2 '=' to the salt - // when base64 decoding it in expensiveBlowfishSetup(). - p.salt = make([]byte, encodedSaltSize, encodedSaltSize+2) - copy(p.salt, hashedSecret[:encodedSaltSize]) - - hashedSecret = hashedSecret[encodedSaltSize:] - p.hash = make([]byte, len(hashedSecret)) - copy(p.hash, hashedSecret) - - return p, nil -} - -func bcrypt(password []byte, cost uint32, salt []byte) ([]byte, error) { - cipherData := make([]byte, len(magicCipherData)) - copy(cipherData, magicCipherData) - - c, err := expensiveBlowfishSetup(password, cost, salt) - if err != nil { - return nil, err - } - - for i := 0; i < 24; i += 8 { - for j := 0; j < 64; j++ { - c.Encrypt(cipherData[i:i+8], cipherData[i:i+8]) - } - } - - // Bug compatibility with C bcrypt implementations. We only encode 23 of - // the 24 bytes encrypted. - hsh := base64Encode(cipherData[:maxCryptedHashSize]) - return hsh, nil -} - -func expensiveBlowfishSetup(key []byte, cost uint32, salt []byte) (*blowfish.Cipher, error) { - - csalt, err := base64Decode(salt) - if err != nil { - return nil, err - } - - // Bug compatibility with C bcrypt implementations. They use the trailing - // NULL in the key string during expansion. - ckey := append(key, 0) - - c, err := blowfish.NewSaltedCipher(ckey, csalt) - if err != nil { - return nil, err - } - - rounds := 1 << cost - for i := 0; i < rounds; i++ { - blowfish.ExpandKey(ckey, c) - blowfish.ExpandKey(csalt, c) - } - - return c, nil -} - -func (p *hashed) Hash() []byte { - arr := make([]byte, 60) - arr[0] = '$' - arr[1] = p.major - n := 2 - if p.minor != 0 { - arr[2] = p.minor - n = 3 - } - arr[n] = '$' - n += 1 - copy(arr[n:], []byte(fmt.Sprintf("%02d", p.cost))) - n += 2 - arr[n] = '$' - n += 1 - copy(arr[n:], p.salt) - n += encodedSaltSize - copy(arr[n:], p.hash) - n += encodedHashSize - return arr[:n] -} - -func (p *hashed) decodeVersion(sbytes []byte) (int, error) { - if sbytes[0] != '$' { - return -1, InvalidHashPrefixError(sbytes[0]) - } - if sbytes[1] > majorVersion { - return -1, HashVersionTooNewError(sbytes[1]) - } - p.major = sbytes[1] - n := 3 - if sbytes[2] != '$' { - p.minor = sbytes[2] - n++ - } - return n, nil -} - -// sbytes should begin where decodeVersion left off. -func (p *hashed) decodeCost(sbytes []byte) (int, error) { - cost, err := strconv.Atoi(string(sbytes[0:2])) - if err != nil { - return -1, err - } - err = checkCost(cost) - if err != nil { - return -1, err - } - p.cost = uint32(cost) - return 3, nil -} - -func (p *hashed) String() string { - return fmt.Sprintf("&{hash: %#v, salt: %#v, cost: %d, major: %c, minor: %c}", string(p.hash), p.salt, p.cost, p.major, p.minor) -} - -func checkCost(cost int) error { - if cost < MinCost || cost > MaxCost { - return InvalidCostError(cost) - } - return nil -} |