diff options
Diffstat (limited to 'src/pkg/crypto/rsa/rsa.go')
| -rw-r--r-- | src/pkg/crypto/rsa/rsa.go | 36 |
1 files changed, 18 insertions, 18 deletions
diff --git a/src/pkg/crypto/rsa/rsa.go b/src/pkg/crypto/rsa/rsa.go index 6aeab041b..e425cf91c 100644 --- a/src/pkg/crypto/rsa/rsa.go +++ b/src/pkg/crypto/rsa/rsa.go @@ -61,7 +61,7 @@ func randomSafePrime(rand io.Reader, bits int) (p *big.Int, err os.Error) { // randomNumber returns a uniform random value in [0, max). func randomNumber(rand io.Reader, max *big.Int) (n *big.Int, err os.Error) { - k := (max.Len() + 7)/8; + k := (max.Len() + 7) / 8; // r is the number of bits in the used in the most significant byte of // max. @@ -81,7 +81,7 @@ func randomNumber(rand io.Reader, max *big.Int) (n *big.Int, err os.Error) { // Clear bits in the first byte to increase the probability // that the candidate is < max. - bytes[0] &= uint8(int(1<<r)-1); + bytes[0] &= uint8(int(1<<r) - 1); n.SetBytes(bytes); if big.CmpInt(n, max) < 0 { @@ -259,8 +259,8 @@ func encrypt(c *big.Int, pub *PublicKey, m *big.Int) *big.Int { // twice the hash length plus 2. func EncryptOAEP(hash hash.Hash, rand io.Reader, pub *PublicKey, msg []byte, label []byte) (out []byte, err os.Error) { hash.Reset(); - k := (pub.N.Len() + 7)/8; - if len(msg) > k - 2 * hash.Size() - 2 { + k := (pub.N.Len() + 7) / 8; + if len(msg) > k-2*hash.Size()-2 { err = MessageTooLongError{}; return; } @@ -270,12 +270,12 @@ func EncryptOAEP(hash hash.Hash, rand io.Reader, pub *PublicKey, msg []byte, lab hash.Reset(); em := make([]byte, k); - seed := em[1 : 1 + hash.Size()]; - db := em[1 + hash.Size() : len(em)]; + seed := em[1 : 1+hash.Size()]; + db := em[1+hash.Size() : len(em)]; - bytes.Copy(db[0 : hash.Size()], lHash); + bytes.Copy(db[0:hash.Size()], lHash); db[len(db)-len(msg)-1] = 1; - bytes.Copy(db[len(db)-len(msg) : len(db)], msg); + bytes.Copy(db[len(db)-len(msg):len(db)], msg); _, err = io.ReadFull(rand, seed); if err != nil { @@ -359,9 +359,9 @@ func decrypt(rand io.Reader, priv *PrivateKey, c *big.Int) (m *big.Int, err os.E // DecryptOAEP decrypts ciphertext using RSA-OAEP. // If rand != nil, DecryptOAEP uses RSA blinding to avoid timing side-channel attacks. func DecryptOAEP(hash hash.Hash, rand io.Reader, priv *PrivateKey, ciphertext []byte, label []byte) (msg []byte, err os.Error) { - k := (priv.N.Len() + 7)/8; + k := (priv.N.Len() + 7) / 8; if len(ciphertext) > k || - k < hash.Size() * 2 + 2 { + k < hash.Size()*2+2 { err = DecryptionError{}; return; } @@ -386,13 +386,13 @@ func DecryptOAEP(hash hash.Hash, rand io.Reader, priv *PrivateKey, ciphertext [] firstByteIsZero := subtle.ConstantTimeByteEq(em[0], 0); - seed := em[1 : hash.Size() + 1]; - db := em[hash.Size() + 1 : len(em)]; + seed := em[1 : hash.Size()+1]; + db := em[hash.Size()+1 : len(em)]; mgf1XOR(seed, hash, db); mgf1XOR(db, hash, seed); - lHash2 := db[0 : hash.Size()]; + lHash2 := db[0:hash.Size()]; // We have to validate the plaintext in contanst time in order to avoid // attacks like: J. Manger. A Chosen Ciphertext Attack on RSA Optimal @@ -407,17 +407,17 @@ func DecryptOAEP(hash hash.Hash, rand io.Reader, priv *PrivateKey, ciphertext [] // invalid: 1 iff we saw a non-zero byte before the 0x01. var lookingForIndex, index, invalid int; lookingForIndex = 1; - rest := db[hash.Size() : len(db)]; + rest := db[hash.Size():len(db)]; for i := 0; i < len(rest); i++ { equals0 := subtle.ConstantTimeByteEq(rest[i], 0); equals1 := subtle.ConstantTimeByteEq(rest[i], 1); - index = subtle.ConstantTimeSelect(lookingForIndex & equals1, i, index); + index = subtle.ConstantTimeSelect(lookingForIndex&equals1, i, index); lookingForIndex = subtle.ConstantTimeSelect(equals1, 0, lookingForIndex); - invalid = subtle.ConstantTimeSelect(lookingForIndex & ^equals0, 1, invalid); + invalid = subtle.ConstantTimeSelect(lookingForIndex&^equals0, 1, invalid); } - if firstByteIsZero & lHash2Good & ^invalid & ^lookingForIndex != 1 { + if firstByteIsZero&lHash2Good&^invalid&^lookingForIndex != 1 { err = DecryptionError{}; return; } @@ -434,6 +434,6 @@ func leftPad(input []byte, size int) (out []byte) { n = size } out = make([]byte, size); - bytes.Copy(out[len(out)-n : len(out)], input); + bytes.Copy(out[len(out)-n:len(out)], input); return; } |