sunrise-choir/shs1-c

Possible failure in shs1_create_client_auth

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snej commented

In shs1_create_client_auth, if the initial call to crypto_scalarmult fails, the function gives up by returning false:

shs1-c/src/shs1.c

Line 94 in ff22068

return false;

Unfortunately the return value is an error code not a boolean, so returning false, i.e. 0, indicates success to the caller. Which is bad news since the caller will be sending uninitialized garbage as the challenge.

I’m not sure under what circumstances crypto_scalarmult can fail, but this seems worth fixing.

AljoschaMeyer commented

Ouch, good catch. @pietgeursen do you know whether this affects any sunrise choir code?