Add binding for EVP_BytesToKey() key derivation function #74
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key.go
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| iv = make([]byte, cipher.IVSize()) | ||
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| var saltPtr, ivPtr, passwordPtr, keyPtr *C.uchar | ||
| if len(salt) != 0 && salt != nil { |
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checking if len(salt) != 0 is sufficient: salt == nil implies len(salt) == 0.
key.go
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| if len(salt) != 0 && salt != nil { | ||
| saltPtr = (*C.uchar)(unsafe.Pointer(&salt[0])) | ||
| } | ||
| if len(iv) != 0 && iv != nil { |
key.go
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| if iterations < 1 { | ||
| return nil, nil, errors.New("iterations count must be 1 or greater") | ||
| } | ||
| passwordSize := C.int(len([]byte(password))) |
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len([]byte(password)) is the same as len(password) but the latter does not make an extra copy.
key.go
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| return nil, nil, errors.New("iterations count must be 1 or greater") | ||
| } | ||
| passwordSize := C.int(len([]byte(password))) | ||
| passwordPtr = (*C.uchar)(unsafe.Pointer(&([]byte(password))[0])) |
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similarly, it's ok to pass &password[0] to c even though password is a string.
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(*C.uchar)(&password[0]) gives error "can not take address of password[0]" (language version 1.7.1). I think this is because of strings in go is not just a byte array
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My mistake! Of course this would be unsafe to do because strings are immutable.
key.go
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| if derivedKeySize != C.int(cipher.KeySize()) { | ||
| return nil, nil, errors.New("key derivation failed") | ||
| } | ||
| return |
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please explicitly return the values
xakep666
changed the title
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Changed "password" parameter type to []byte because EVP_BytesToKey takes password as (unsigned char *) |
| iv = make([]byte, cipher.IVSize()) | ||
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| var saltPtr, ivPtr, passwordPtr, keyPtr *C.uchar | ||
| if len(salt) != 0 { |
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so reading some openssl docs (https://wiki.openssl.org/index.php/Manual:EVP_BytesToKey(3)) this field should be either 8 bytes or null. can we have the function return an error if salt is passed and not 8 bytes?
xakep666
changed the title
This function generates key and IV using salt and passphrase.
It used to decrypt data with "Salted__" header