package ctr import ( "bytes" gCipher "crypto/cipher" "r00t2.io/sshkeys/internal" "r00t2.io/sshkeys/internal/ciphers/aesCommon" ) // Setup populates a Cipher from a key. The key must include the IV suffixed to the actual key. func (c *Cipher) Setup(key []byte) (err error) { if c == nil { *c = Cipher{ &aesCommon.AesCipher{}, } } if err = c.CipherSetup(key, aesCommon.Aes192Bits); err != nil { return } return } // Name returns the name as used in the key file bytes. func (c *Cipher) Name() (name string) { name = Name return } // NameBytes returns the byte form of Cipher.Name with leading bytecount allocator. func (c *Cipher) NameBytes() (name []byte) { var err error if name, err = internal.PackBytes(Name); err != nil { return } return } /* Encrypt encrypts data (a string, []byte, byte, *bytes.Buffer, or *bytes.Reader) to the *bytes.Reader encrypted. NOTE: Padding IS applied automatically. NOTE: If data is a *bytes.Buffer, no bytes will be consumed -- the bytes are taken in entirety without consuming them (Buffer.Bytes()). It is up to the caller to consume the buffer as desired beforehand or isolate to a specific sub-buffer beforehand to pass to Cipher.Encrypt. NOTE: If data is a *bytes.Reader, ALL bytes WILL be consumed. */ func (c *Cipher) Encrypt(data interface{}) (encrypted *bytes.Reader, err error) { var padded []byte var cryptDst []byte var cryptBlock gCipher.Block var crypter gCipher.Stream if cryptDst, padded, cryptBlock, err = c.GetCryptBlock(data); err != nil { return } crypter = gCipher.NewCTR(cryptBlock, c.IV) crypter.XORKeyStream(cryptDst, padded) encrypted = bytes.NewReader(cryptDst) return } /* AllocateEncrypt is the same as Cipher.Encrypt but includes an unencrypted byte allocator prefix. NOTE: Padding IS applied automatically. NOTE: If data is a *bytes.Buffer, no bytes will be consumed -- the bytes are taken in entirety without consuming them (Buffer.Bytes()). It is up to the caller to consume the buffer as desired beforehand or isolate to a specific sub-buffer beforehand to pass to Cipher.AllocateEncrypt. NOTE: If data is a *bytes.Reader, ALL bytes WILL be consumed. */ func (c *Cipher) AllocateEncrypt(data interface{}) (encrypted *bytes.Reader, err error) { var b *bytes.Reader var buf *bytes.Buffer = new(bytes.Buffer) var alloc []byte = make([]byte, 4) if b, err = c.Encrypt(data); err != nil { return } if alloc, err = internal.PackBytes(b); err != nil { return } if _, err = buf.Write(alloc); err != nil { return } if _, err = b.WriteTo(buf); err != nil { return } encrypted = bytes.NewReader(buf.Bytes()) return } /* Decrypt takes a raw byte slice, a *bytes.Buffer, or a *bytes.Reader and returns a plain/decrypted *bytes.Reader. NOTE: The decrypted data contains padding. It is up to the caller to remove/strip. NOTE: If data is a *bytes.Buffer, no bytes will be consumed -- the bytes are taken in entirety without consuming them (Buffer.Bytes()). It is up to the caller to consume the buffer as desired beforehand or isolate to a specific sub-buffer beforehand to pass to Cipher.Decrypt. NOTE: If data is a *bytes.Reader, ALL bytes WILL be consumed. */ func (c *Cipher) Decrypt(data interface{}) (decrypted *bytes.Reader, err error) { var plain []byte var padded []byte var cryptBlock gCipher.Block var decrypter gCipher.Stream if plain, padded, cryptBlock, err = c.GetDecryptBlock(data); err != nil { return } decrypter = gCipher.NewCTR(cryptBlock, c.IV) decrypter.XORKeyStream(plain, padded) decrypted = bytes.NewReader(plain) return } /* AllocatedDecrypt is the same as Cipher.Decrypt but assumes that data includes an unencrypted uint32 byte allocator prefix. Be *extremely* certain of this, as things can get REALLY weird if you pass in data that doesn't actually have that prefix. NOTE: The decrypted data contains padding. It is up to the caller to remove/strip. NOTE: If data is a bytes.Buffer pointer, it will consume ONLY the leading prefix and the length of bytes the prefix indicates and no more. NOTE: If data is a *bytes.Reader, it will consume ONLY the leading prefix and the length of bytes the prefix indicates and no more. */ func (c *Cipher) AllocatedDecrypt(data interface{}) (decrypted *bytes.Reader, err error) { var b []byte if b, err = internal.UnpackBytes(data); err != nil { return } if decrypted, err = c.Decrypt(b); err != nil { return } return }