I have implemented HKDF by myself and it seems to work good. I managed to replicate all the test vectors listed here but... except this one:
Test with SHA-256 and longer inputs/outputs Hash = SHA-256 IKM = 0x000102030405060708090a0b0c0d0e0f 101112131415161718191a1b1c1d1e1f 202122232425262728292a2b2c2d2e2f 303132333435363738393a3b3c3d3e3f 404142434445464748494a4b4c4d4e4f (80 octets) salt = 0x606162636465666768696a6b6c6d6e6f 707172737475767778797a7b7c7d7e7f 808182838485868788898a8b8c8d8e8f 909192939495969798999a9b9c9d9e9f a0a1a2a3a4a5a6a7a8a9aaabacadaeaf (80 octets) info = 0xb0b1b2b3b4b5b6b7b8b9babbbcbdbebf c0c1c2c3c4c5c6c7c8c9cacbcccdcecf d0d1d2d3d4d5d6d7d8d9dadbdcdddedf e0e1e2e3e4e5e6e7e8e9eaebecedeeef f0f1f2f3f4f5f6f7f8f9fafbfcfdfeff (80 octets) L = 82 PRK = 0x06a6b88c5853361a06104c9ceb35b45c ef760014904671014a193f40c15fc244 (32 octets) OKM = 0xb11e398dc80327a1c8e7f78c596a4934 4f012eda2d4efad8a050cc4c19afa97c 59045a99cac7827271cb41c65e590e09 da3275600c2f09b8367793a9aca3db71 cc30c58179ec3e87c14c01d5c1f3434f 1d87 (82 octets)
After one hour of debug, I figured out (and I believe) that my implementation is right and that this test vector is wrong.
I don't manage to get the right
OKM value and even the
PRK is wrong. To discover this I did the following:
PRK = HMAC-Hash(salt, IKM) (as described in the RFC), I tried to compute the HMAC and I saw that the result value was different.
Can anyone confirm that this test vector is "bugged"?