I'm not quite following the problem. You can encode the secret/key using Base32. In fact this Keycloak already stores the secret as a Base32 encoded string. We don't strictly support hardware tokens at the moment as there's no way to specify the secret, but you can probably do that through the admin endpoints.

Yep, I've already done it (via custom realm resources, since there is no SPI for custom *admin* resources yet).

To be accurate: KeyCloak *stores* HOTP secrets as plain strings, but transfers them to phones as Base32. For example:

s7hAVBHOOPvAnTa3w4mh - this is what is stored in the database (plain string)

OM3W QQKW IJEE 6T2Q OZAW 4VDB GN3T I3LI - this is printed out to be entered into FreeOTP / Google Authenticator

When authenticating, the plain string is converted to bytes and used as a secret for HmacOTP. Since storage type is String/VARCHAR, such a secret is limited to printable characters.

My intention was to use the KeyCloak's standard HOTP authenticator to validate OTPs generated by hardware tokens. Unfortunately, tokens that I'm working with (namely Aladdin eToken PASS) are programmed with seeds that contain arbitrary bytes, and therefore they cannot be stored into Credential's "value" field.

But now it turns out that I'll have to implement custom authenticator either way. Thus, I'll just store seeds as hex string and decode them in my authenticator before calling HmacOTP. I'll probably use different credential type, ex., "hotp+", in order not to mess up with KeyCloak OTP.

By the way, do you think having a SPI for credential types could be a good idea (custom/proprietary OTP algorithms; custom storage format, like in my case)? At the moment, all the supported credential types (password, HOTP/TOTP etc.) are hardcoded into org.keycloak.models.utils.CredentialValidation. If we had a SPI, it would become possible to add new types without modifying KeyCloak code - and all the code that uses context.getSession().users().validCredentials(...) could make use of new credential types.

Cheers,

Mitya

On 13 June 2016 at 20:14, Mitya <mitya@cargosoft.ru> wrote:

The current KeyCloak HOTP implementation assumes that a HOTP key (aka
seed, aka initialization vector) is stored as string, and thus contains
only printable characters. However, the HOTP standard (RFC 4226)
doesn't impose any restrictions on key material; any arbitrary byte
array is acceptable.

Moreover, many hardware HOTP tokens are pre-programmed at the factory,
and do contain non-printable seeds. Even though KeyCloak doesn't
support hardware tokens out of the box, developers could implement it
by extending KeyCloak and employing existing algorithms. Unfortunately,
the existing convention (to store HOTP seeds as printable strings)
makes this impossible.

For the "password" credential type, the "value" field is already stored
as Base64. I think "hotp" credentials could also be stored as Base64 or
hex; another option would be to store the "value" field as BLOB (like
it's already done for the "salt" field).

I think I could produce a PR for this, I only need to know which
scenario is preferred.

Cheers,

Mitya

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