On 14/01/18 15:26, Chris B wrote: > I'm trying to help someone recover his password for an older format > ethereum encrypted private key (EPK). My plan has been to use his best > guess at the password to brute force the actual password. > > The EPK is a 132 character string, and it looks something like this: > U2FsdGV0X185M9YAa/27pmEvFzC5pqLI4xWrA6ouGVCx0EeJ9s8DzeGuBtYJPDCKDy0m80yvHdQYDMPa+Hwv2JPbuGJNoUMhFWpcQW1VF+EAy0tYb7Wtv2+IRWZzcpsE8e2a > > (That is: 128 ASCII digits and/or letters, plus three "+" and a "/".) > > This article > (https://www.reddit.com/r/Bitcoin/comments/3gwdge/importing_old_encrypted_private_keys/) > seems to describe a very similar EPK. The author of that post decrypted > their key with the following command: > > openssl enc -in FILE_OF_KEYS -a -d -salt -aes256 -pass pass:"PASSWORD_HERE" > > I have tried this same approach, but I'm getting an error: > > EVP_DecryptFinal_ex:wrong final block length What version of OpenSSL are you using. The quoted article was written 2 years ago so definitely wasn't using OpenSSL 1.1.0. If you *are* using 1.1.0 then the default digest was changed between 1.0.2 and 1.1.0. Old OpenSSL "enc" output defaulted to md5. The current default is sha256: https://www.openssl.org/docs/faq.html#USER3 Try adding "-md md5" onto your command line. Matt > > Here's an example: > > /usr/bin/openssl enc -d -aes-256-cbc -a -in enc_private_key.txt -out > recovered.key -pass pass:TheBig7ebowski > > And here's the output: > > bad decrypt > > 140220549330848:error:0606506D:digital envelope > routines:EVP_DecryptFinal_ex:wrong final block length:evp_enc.c:581: > > I'm not sure how to interpret that output. I could interpret it as: > o Your system for decrypting the password is perfect, but: this is not > the right password. > o There's something wrong with the EPK -- its length must be a multiple > of the AES block length. > o There's something wrong with the unencrypted private key -- its length > must be a multiple of the AES block length. > o Something else entirely > > Can anyone help me understand how to interpret this error message? > > Thanks, > Chris > > -- openssl-users mailing list To unsubscribe: https://mta.openssl.org/mailman/listinfo/openssl-users
