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Worries Arise About Security of New WebAuthn Protocol (zdnet.com)
An anonymous reader writes: "A team of security researchers has raised the alarm about some cryptography-related issues with the newly released WebAuthn passwordless authentication protocol," reports ZDNet. "The new WebAuthn protocol will allow users of a device -- such as a computer or a smartphone -- to authenticate on a website using a USB security key, a biometric solution, or his computer or smartphone's password." But researchers say that because WebAuthn uses weak algorithms for the operations of registering a new device, they can pull off some attacks against it.
"If converted into a practical exploit, the ECDAA attacks discussed in the article would allow attackers to steal the key from a [server's] TPM, which would allow attackers to effectively clone the user's hardware security token remotely," Arciszewski, one of the researchers, told ZDNet. "The scenarios that follow depend on how much trust was placed into the hardware security token," he added. "At minimum, I imagine it would enable 2FA bypasses and re-enable phishing attacks. However, if companies elected to use hardware security tokens to obviate passwords, it would allow direct user impersonation by attackers." Attacks aren't practical, and experts say the root cause relies in badly written documentation that may fool some implementers into supporting the old algorithms instead of newer and more solid ones. The FIDO Alliance was notified and has started work on updating its docs so it won't look like it's recommending ECDAA or RSASSA-PKCS1-v1_5. "PKCS1v1.5 is bad. The exploits are almost old enough to legally drink alcohol in the United States," Arciszewski said.
"If converted into a practical exploit, the ECDAA attacks discussed in the article would allow attackers to steal the key from a [server's] TPM, which would allow attackers to effectively clone the user's hardware security token remotely," Arciszewski, one of the researchers, told ZDNet. "The scenarios that follow depend on how much trust was placed into the hardware security token," he added. "At minimum, I imagine it would enable 2FA bypasses and re-enable phishing attacks. However, if companies elected to use hardware security tokens to obviate passwords, it would allow direct user impersonation by attackers." Attacks aren't practical, and experts say the root cause relies in badly written documentation that may fool some implementers into supporting the old algorithms instead of newer and more solid ones. The FIDO Alliance was notified and has started work on updating its docs so it won't look like it's recommending ECDAA or RSASSA-PKCS1-v1_5. "PKCS1v1.5 is bad. The exploits are almost old enough to legally drink alcohol in the United States," Arciszewski said.
The could link webauthn to classic certificates because they are directly available and even we could use today as SSL option.
But, for some reason, browser developers (MS,Google, Mozilla Foundation...) has removed signature functionality without develop an alternative and WebAuthn seems to go into the same logic pushing new hardware without put an option to use classical cryptographic standards ( RSA tokens, PKCS11, CryptoAPI on Windows...) from the same WebAuthn.
It seems that they try to destroy PKI instead of create a true replacement of passwords. PKI is available now, altough WebAuthn could add PKI as an option. But It seems that they don't want to do it and It seems even probably to me that if they are success, they will try to kill PKI later supressing SSL client certificates as a authentication system in a future when WebAuthn was well adopted.
PKI authentication and signature directly available on Browser should be a high priority functionality, but they refuse to do it. Why?
The problem with a password isn't just that you have to remember it, but that you give your secret away every time you try to log in to a service. So if there is a man-in-the-middle or you just accidentally entered the password into the wrong server, your password is now compromised. There are plenty of better ways to do authentication that don't require exposing your secret.