// hash password and salt
func (ctx *Context) hash(password []byte, salt []byte) ([]byte, error) {
if len(password) == 0 {
return nil, ErrPassword
}
if len(salt) == 0 {
return nil, ErrSalt
}
hash := make([]byte, ctx.HashLen)
// optional secret
secret := (*C.uint8_t)(nil)
if len(ctx.Secret) > 0 {
secret = (*C.uint8_t)(&ctx.Secret[0])
}
// optional associated data
associatedData := (*C.uint8_t)(nil)
if len(ctx.AssociatedData) > 0 {
associatedData = (*C.uint8_t)(&ctx.AssociatedData[0])
}
// optional flags
flags := C.ARGON2_DEFAULT_FLAGS
if ctx.Flags != 0 {
flags = ctx.Flags
}
// wrapper to overcome go pointer passing limitations
result := C.argon2_wrapper(
(*C.uint8_t)(&hash[0]), C.uint32_t(ctx.HashLen),
(*C.uint8_t)(&password[0]), C.uint32_t(len(password)),
(*C.uint8_t)(&salt[0]), C.uint32_t(len(salt)),
secret, C.uint32_t(len(ctx.Secret)),
associatedData, C.uint32_t(len(ctx.AssociatedData)),
C.uint32_t(ctx.Iterations),
C.uint32_t(ctx.Memory),
C.uint32_t(ctx.Parallelism),
C.uint32_t(ctx.Parallelism),
C.uint32_t(ctx.Version),
nil, nil,
C.uint32_t(flags),
C.argon2_type(ctx.Mode))
if result != C.ARGON2_OK {
return nil, Error(result)
}
return hash, nil
}
// HashEncoded hashes a password and produces a crypt-like encoded string.
func HashEncoded(ctx *Context, password []byte, salt []byte) (string, error) {
if ctx == nil {
return "", ErrContext
}
if len(password) == 0 {
return "", ErrPassword
}
if len(salt) == 0 {
return "", ErrSalt
}
encodedlen := C.argon2_encodedlen(
C.uint32_t(ctx.Iterations),
C.uint32_t(ctx.Memory),
C.uint32_t(ctx.Parallelism),
C.uint32_t(len(salt)),
C.uint32_t(ctx.HashLen))
s := make([]byte, encodedlen)
result := C.argon2_hash(
C.uint32_t(ctx.Iterations),
C.uint32_t(ctx.Memory),
C.uint32_t(ctx.Parallelism),
unsafe.Pointer(&password[0]), C.size_t(len(password)),
unsafe.Pointer(&salt[0]), C.size_t(len(salt)),
nil, C.size_t(ctx.HashLen),
(*C.char)(unsafe.Pointer(&s[0])), C.size_t(encodedlen),
C.argon2_type(ctx.Mode),
C.uint32_t(ctx.Version))
if result != C.ARGON2_OK {
return "", Error(result)
}
// Strip trailing null byte(s)
s = bytes.TrimRight(s, "\x00")
return string(s), nil
}
// VerifyEncoded verifies an encoded Argon2 hash s against a plaintext password.
func VerifyEncoded(s string, password []byte) (bool, error) {
mode, err := getMode(s)
if err != nil {
return false, err
}
cs := C.CString(s)
defer C.free(unsafe.Pointer(cs))
result := C.argon2_verify(
cs,
unsafe.Pointer(&password[0]),
C.size_t(len(password)),
C.argon2_type(mode))
if result == C.ARGON2_OK {
return true, nil
} else if result == C.ARGON2_VERIFY_MISMATCH {
return false, nil
}
// argon2_verify always seems to return an error in this case...
return false, Error(result)
}
