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  3. I reported an insecure DKIM key to Deutsche Telekom / T-Systems.

I reported an insecure DKIM key to Deutsche Telekom / T-Systems.

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  • yacc143@mastodon.socialY yacc143@mastodon.social

    @Bebef
    It's probably not, some countries have really tough laws that they apply to email delivery and privacy that makes even spam filtering a legally dicey proposition

    But let me put it like this, who wants to sue a company that has a legal budget bigger than the whole government budget of some of the poorer EU MS?

    And in the end as long as the users won't start moving their fat posteriors away from the big tech monopolies, ...
    @kkarhan @momo @badkeys @BNetzA @EUCommission

    yacc143@mastodon.socialY This user is from outside of this forum
    yacc143@mastodon.socialY This user is from outside of this forum
    yacc143@mastodon.social
    wrote last edited by
    #31

    @Bebef
    The really odd thing is it's not the oldies that nowadays are a problem, it's the youngsters, we literally had a complaint today about the PIM/office suite we use, our CEO nicely played that one. He's open to all proposals for alternatives from a company headquartered in the EEA for legal reasons.

    Interestingly the C level has no problem IMAP, and accessing the calendar over CalDAV. But the youngsters have never heard of these @kkarhan @momo @badkeys @BNetzA @EUCommission

    yacc143@mastodon.socialY 1 Reply Last reply
    0
    • yacc143@mastodon.socialY yacc143@mastodon.social

      @Bebef
      The really odd thing is it's not the oldies that nowadays are a problem, it's the youngsters, we literally had a complaint today about the PIM/office suite we use, our CEO nicely played that one. He's open to all proposals for alternatives from a company headquartered in the EEA for legal reasons.

      Interestingly the C level has no problem IMAP, and accessing the calendar over CalDAV. But the youngsters have never heard of these @kkarhan @momo @badkeys @BNetzA @EUCommission

      yacc143@mastodon.socialY This user is from outside of this forum
      yacc143@mastodon.socialY This user is from outside of this forum
      yacc143@mastodon.social
      wrote last edited by
      #32

      things. And are shocked that email can be provided by something else then Google, outlook or Apple. On which of these is our email hosted I was asked. I had to explain very slowly that we are on the small option "other".
      @kkarhan @momo @badkeys @BNetzA @EUCommission @Bebef

      1 Reply Last reply
      0
      • tanja@mastodon.catgirl.cloudT tanja@mastodon.catgirl.cloud

        @badkeys@infosec.exchange oooofffff

        But why would they turn down the bug bounty????

        <img class="not-responsive emoji" src="https://content.mastodon.catgirl.cloud/custom_emojis/images/000/055/198/original/neocat_googly_shocked.png" title=":neocat_googly_shocked:" />

        oscherler@tooting.chO This user is from outside of this forum
        oscherler@tooting.chO This user is from outside of this forum
        oscherler@tooting.ch
        wrote last edited by
        #33

        @tanja Because they’re cheap assholes? Just a wild guess.

        m_berberich@chaos.socialM 1 Reply Last reply
        0
        • keksdosenmann@mastodon.socialK keksdosenmann@mastodon.social

          @badkeys Telekom. Die machen das.

          christianrickert@23.socialC This user is from outside of this forum
          christianrickert@23.socialC This user is from outside of this forum
          christianrickert@23.social
          wrote last edited by
          #34

          @keksdosenmann @badkeys

          Die schaffen uns. 😮‍💨

          1 Reply Last reply
          1
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          • lunareclipse@snug.moeL lunareclipse@snug.moe

            @badkeys bad companies that don't pay out bug bounties can have uncoordinated public disclosure as a treat :3

            kbruen@procial.tchncs.deK This user is from outside of this forum
            kbruen@procial.tchncs.deK This user is from outside of this forum
            kbruen@procial.tchncs.de
            wrote last edited by
            #35

            @lunareclipse@snug.moe @badkeys@infosec.exchange I mean, if it's out of scope, then it's not even a disclosure, as "out of scope" is an admittance that it's no biggie for the information to be public to begin with, right?

            1 Reply Last reply
            0
            • badkeys@infosec.exchangeB badkeys@infosec.exchange

              I reported an insecure DKIM key to Deutsche Telekom / T-Systems. They first asked me to further explain things (not sure why 'Here's your DKIM private key' needs more explanation, but whatever...). Then they told me it's out of scope for their bugbounty.

              I guess then there's really no reason not to tell you: They have a 384 bit RSA DKIM key configured at: dkim._domainkey.t-systems.nl

              384 bit RSA is... how shall I put it? I think 512 bit is the lowest RSA key size that was ever really used. 384 bit RSA is crackable in a few hours on a modern PC (using cado-nfs). The private key is:
              -----BEGIN RSA PRIVATE KEY-----
              MIHxAgEAAjEAtTliQYV2Xvx1OGkDyOL799BTFEuobY2dn2AgtiKCQgrh78NVK1JK
              j0yRXgNnPpGBAgMBAAECMF0t+TBZUCi8xATSMij7VLTxv5Xi5OIXesNiXOKtYIRP
              LkpYfR5PggaMScfbmqSssQIZAMwOhm9d7Y7Qi7I2j1AlYbiqdtqO54T7FQIZAONa
              9dJFkC6lM3EPXR+0SZ4dqwwpiM0nvQIYYgz8thi5JK264ohq9sTvnu9yKvUN9I09
              AhgfgMYZKcxtujRjkSZtMzUUNLYzzDmJe90CGDKwqcBI0v9ChaR8WHht+/chMdxj
              7ez94w==
              -----END RSA PRIVATE KEY-----

              robot@wetdry.worldR This user is from outside of this forum
              robot@wetdry.worldR This user is from outside of this forum
              robot@wetdry.world
              wrote last edited by
              #36

              @badkeys ReallySecureAlgorithm

              1 Reply Last reply
              0
              • badkeys@infosec.exchangeB badkeys@infosec.exchange

                I reported an insecure DKIM key to Deutsche Telekom / T-Systems. They first asked me to further explain things (not sure why 'Here's your DKIM private key' needs more explanation, but whatever...). Then they told me it's out of scope for their bugbounty.

                I guess then there's really no reason not to tell you: They have a 384 bit RSA DKIM key configured at: dkim._domainkey.t-systems.nl

                384 bit RSA is... how shall I put it? I think 512 bit is the lowest RSA key size that was ever really used. 384 bit RSA is crackable in a few hours on a modern PC (using cado-nfs). The private key is:
                -----BEGIN RSA PRIVATE KEY-----
                MIHxAgEAAjEAtTliQYV2Xvx1OGkDyOL799BTFEuobY2dn2AgtiKCQgrh78NVK1JK
                j0yRXgNnPpGBAgMBAAECMF0t+TBZUCi8xATSMij7VLTxv5Xi5OIXesNiXOKtYIRP
                LkpYfR5PggaMScfbmqSssQIZAMwOhm9d7Y7Qi7I2j1AlYbiqdtqO54T7FQIZAONa
                9dJFkC6lM3EPXR+0SZ4dqwwpiM0nvQIYYgz8thi5JK264ohq9sTvnu9yKvUN9I09
                AhgfgMYZKcxtujRjkSZtMzUUNLYzzDmJe90CGDKwqcBI0v9ChaR8WHht+/chMdxj
                7ez94w==
                -----END RSA PRIVATE KEY-----

                diziet@mastodon.me.ukD This user is from outside of this forum
                diziet@mastodon.me.ukD This user is from outside of this forum
                diziet@mastodon.me.uk
                wrote last edited by
                #37

                @badkeys
                Not the same at all, but here are most of my dkim private keys https://www.chiark.greenend.org.uk/dkim-rotate/README.txt

                badrihippo@fosstodon.orgB 1 Reply Last reply
                0
                • R relay@relay.infosec.exchange shared this topic
                • badkeys@infosec.exchangeB badkeys@infosec.exchange

                  I reported an insecure DKIM key to Deutsche Telekom / T-Systems. They first asked me to further explain things (not sure why 'Here's your DKIM private key' needs more explanation, but whatever...). Then they told me it's out of scope for their bugbounty.

                  I guess then there's really no reason not to tell you: They have a 384 bit RSA DKIM key configured at: dkim._domainkey.t-systems.nl

                  384 bit RSA is... how shall I put it? I think 512 bit is the lowest RSA key size that was ever really used. 384 bit RSA is crackable in a few hours on a modern PC (using cado-nfs). The private key is:
                  -----BEGIN RSA PRIVATE KEY-----
                  MIHxAgEAAjEAtTliQYV2Xvx1OGkDyOL799BTFEuobY2dn2AgtiKCQgrh78NVK1JK
                  j0yRXgNnPpGBAgMBAAECMF0t+TBZUCi8xATSMij7VLTxv5Xi5OIXesNiXOKtYIRP
                  LkpYfR5PggaMScfbmqSssQIZAMwOhm9d7Y7Qi7I2j1AlYbiqdtqO54T7FQIZAONa
                  9dJFkC6lM3EPXR+0SZ4dqwwpiM0nvQIYYgz8thi5JK264ohq9sTvnu9yKvUN9I09
                  AhgfgMYZKcxtujRjkSZtMzUUNLYzzDmJe90CGDKwqcBI0v9ChaR8WHht+/chMdxj
                  7ez94w==
                  -----END RSA PRIVATE KEY-----

                  selea@social.linux.pizzaS This user is from outside of this forum
                  selea@social.linux.pizzaS This user is from outside of this forum
                  selea@social.linux.pizza
                  wrote last edited by
                  #38

                  @badkeys

                  What wat. they published the private key?!

                  kramse@helvede.netK 1 Reply Last reply
                  0
                  • badkeys@infosec.exchangeB badkeys@infosec.exchange

                    I reported an insecure DKIM key to Deutsche Telekom / T-Systems. They first asked me to further explain things (not sure why 'Here's your DKIM private key' needs more explanation, but whatever...). Then they told me it's out of scope for their bugbounty.

                    I guess then there's really no reason not to tell you: They have a 384 bit RSA DKIM key configured at: dkim._domainkey.t-systems.nl

                    384 bit RSA is... how shall I put it? I think 512 bit is the lowest RSA key size that was ever really used. 384 bit RSA is crackable in a few hours on a modern PC (using cado-nfs). The private key is:
                    -----BEGIN RSA PRIVATE KEY-----
                    MIHxAgEAAjEAtTliQYV2Xvx1OGkDyOL799BTFEuobY2dn2AgtiKCQgrh78NVK1JK
                    j0yRXgNnPpGBAgMBAAECMF0t+TBZUCi8xATSMij7VLTxv5Xi5OIXesNiXOKtYIRP
                    LkpYfR5PggaMScfbmqSssQIZAMwOhm9d7Y7Qi7I2j1AlYbiqdtqO54T7FQIZAONa
                    9dJFkC6lM3EPXR+0SZ4dqwwpiM0nvQIYYgz8thi5JK264ohq9sTvnu9yKvUN9I09
                    AhgfgMYZKcxtujRjkSZtMzUUNLYzzDmJe90CGDKwqcBI0v9ChaR8WHht+/chMdxj
                    7ez94w==
                    -----END RSA PRIVATE KEY-----

                    artlog@agora.l0g.euA This user is from outside of this forum
                    artlog@agora.l0g.euA This user is from outside of this forum
                    artlog@agora.l0g.eu
                    wrote last edited by
                    #39
                    @badkeys

                    I don't remember have ever seen lower RSA keys size than 512 bits... We have a winner here !
                    1 Reply Last reply
                    0
                    • momo@social.linux.pizzaM momo@social.linux.pizza

                      @badkeys
                      Do they accept mails from noncommercial mailservers at their nl branch or do they refuse them with "554 None/Bad Reputation" as the german branch does, unless the mail admin publishes full personal (!) contact infos on a webserver hosted on the smtp machine? Just asking, because THOSE guys behave like they wrote the SMTP RFCs all by themselves...

                      bekopharm@indieweb.socialB This user is from outside of this forum
                      bekopharm@indieweb.socialB This user is from outside of this forum
                      bekopharm@indieweb.social
                      wrote last edited by
                      #40

                      @momo Hab mich damit auch schon herum geärgert und mit einem "Musterbrief" frei gekauft: https://beko.famkos.net/2023/06/02/%c2%b7t%c2%b7%c2%b7%c2%b7error/

                      Die haben doch echt nicht mehr alle Latten am Zaun o0

                      momo@social.linux.pizzaM 1 Reply Last reply
                      0
                      • selea@social.linux.pizzaS selea@social.linux.pizza

                        @badkeys

                        What wat. they published the private key?!

                        kramse@helvede.netK This user is from outside of this forum
                        kramse@helvede.netK This user is from outside of this forum
                        kramse@helvede.net
                        wrote last edited by
                        #41

                        @selea @badkeys

                        no, sounds like they stayed for tooo long on a short length that could be cracked quickly.

                        they should upgrade to more bits, and re-roll their keys

                        1 Reply Last reply
                        0
                        • buherator@infosec.placeB buherator@infosec.place
                          @mcr314 @badkeys Source? I doubt someone who makes a mistake like this knows what ECDSA is.
                          J This user is from outside of this forum
                          J This user is from outside of this forum
                          janet_catcus@hachyderm.io
                          wrote last edited by
                          #42

                          @buherator @badkeys @mcr314 probably done by an apprentice anyway

                          1 Reply Last reply
                          0
                          • diziet@mastodon.me.ukD diziet@mastodon.me.uk

                            @badkeys
                            Not the same at all, but here are most of my dkim private keys https://www.chiark.greenend.org.uk/dkim-rotate/README.txt

                            badrihippo@fosstodon.orgB This user is from outside of this forum
                            badrihippo@fosstodon.orgB This user is from outside of this forum
                            badrihippo@fosstodon.org
                            wrote last edited by
                            #43

                            @Diziet 😮 never even thought this could be a thing!

                            So you're basically making it impossible to prove through DKIM signatures that a given email was actually sent from your server?

                            @badkeys

                            diziet@mastodon.me.ukD 1 Reply Last reply
                            0
                            • badkeys@infosec.exchangeB badkeys@infosec.exchange

                              I reported an insecure DKIM key to Deutsche Telekom / T-Systems. They first asked me to further explain things (not sure why 'Here's your DKIM private key' needs more explanation, but whatever...). Then they told me it's out of scope for their bugbounty.

                              I guess then there's really no reason not to tell you: They have a 384 bit RSA DKIM key configured at: dkim._domainkey.t-systems.nl

                              384 bit RSA is... how shall I put it? I think 512 bit is the lowest RSA key size that was ever really used. 384 bit RSA is crackable in a few hours on a modern PC (using cado-nfs). The private key is:
                              -----BEGIN RSA PRIVATE KEY-----
                              MIHxAgEAAjEAtTliQYV2Xvx1OGkDyOL799BTFEuobY2dn2AgtiKCQgrh78NVK1JK
                              j0yRXgNnPpGBAgMBAAECMF0t+TBZUCi8xATSMij7VLTxv5Xi5OIXesNiXOKtYIRP
                              LkpYfR5PggaMScfbmqSssQIZAMwOhm9d7Y7Qi7I2j1AlYbiqdtqO54T7FQIZAONa
                              9dJFkC6lM3EPXR+0SZ4dqwwpiM0nvQIYYgz8thi5JK264ohq9sTvnu9yKvUN9I09
                              AhgfgMYZKcxtujRjkSZtMzUUNLYzzDmJe90CGDKwqcBI0v9ChaR8WHht+/chMdxj
                              7ez94w==
                              -----END RSA PRIVATE KEY-----

                              linear@nya.socialL This user is from outside of this forum
                              linear@nya.socialL This user is from outside of this forum
                              linear@nya.social
                              wrote last edited by
                              #44
                              @badkeys@infosec.exchange just a few days ago i broke an rsa384 key using yafu on my home server (a ~6 year old dell poweredge, fairly decent spec) as a practice run for something, and it took under 5 minutes
                              linear@nya.socialL 1 Reply Last reply
                              0
                              • linear@nya.socialL linear@nya.social
                                @badkeys@infosec.exchange just a few days ago i broke an rsa384 key using yafu on my home server (a ~6 year old dell poweredge, fairly decent spec) as a practice run for something, and it took under 5 minutes
                                linear@nya.socialL This user is from outside of this forum
                                linear@nya.socialL This user is from outside of this forum
                                linear@nya.social
                                wrote last edited by
                                #45
                                @badkeys@infosec.exchange the yafu help describes using siqs for this, which would take that server 2 to 3 hours, but using nfs it took only minutes
                                1 Reply Last reply
                                0
                                • bekopharm@indieweb.socialB bekopharm@indieweb.social

                                  @momo Hab mich damit auch schon herum geärgert und mit einem "Musterbrief" frei gekauft: https://beko.famkos.net/2023/06/02/%c2%b7t%c2%b7%c2%b7%c2%b7error/

                                  Die haben doch echt nicht mehr alle Latten am Zaun o0

                                  momo@social.linux.pizzaM This user is from outside of this forum
                                  momo@social.linux.pizzaM This user is from outside of this forum
                                  momo@social.linux.pizza
                                  wrote last edited by
                                  #46

                                  @bekopharm
                                  Ich konnte sie auf ein Kontaktformular runterhandeln, musste aber versichern, dass der Transport dann nicht per eMail erfolgt. Ich habe ne ntfy-Instanz auf einem meiner Server laufen, das Webformular generiert jetzt eine Notification auf mein Smartphone.

                                  Eigentlich wollte ich den Zugriff per Firewall auf die Admin-Netzwerke der Telekom zumachen, aber das war für sie absolut inakzeptabel.

                                  Aber bei jeder Gelegenheit seine eigenen Kunden in Geiselhaft nehmen und rumprotzen, dass sie der größte Provider Deutschlands sind und damit eigene Regeln festlegen können, an die sich jeder zu halten hat.

                                  j_r@social.jugendhacker.deJ 1 Reply Last reply
                                  0
                                  • oscherler@tooting.chO oscherler@tooting.ch

                                    @tanja Because they’re cheap assholes? Just a wild guess.

                                    m_berberich@chaos.socialM This user is from outside of this forum
                                    m_berberich@chaos.socialM This user is from outside of this forum
                                    m_berberich@chaos.social
                                    wrote last edited by
                                    #47

                                    @oscherler @tanja

                                    Or they did not understand the problem?

                                    1 Reply Last reply
                                    0
                                    • lunareclipse@snug.moeL lunareclipse@snug.moe

                                      @badkeys bad companies that don't pay out bug bounties can have uncoordinated public disclosure as a treat :3

                                      yama@tech.lgbtY This user is from outside of this forum
                                      yama@tech.lgbtY This user is from outside of this forum
                                      yama@tech.lgbt
                                      wrote last edited by
                                      #48

                                      @lunareclipse @badkeys "bad companies", so most of them by nature ?

                                      1 Reply Last reply
                                      0
                                      • badkeys@infosec.exchangeB badkeys@infosec.exchange

                                        I reported an insecure DKIM key to Deutsche Telekom / T-Systems. They first asked me to further explain things (not sure why 'Here's your DKIM private key' needs more explanation, but whatever...). Then they told me it's out of scope for their bugbounty.

                                        I guess then there's really no reason not to tell you: They have a 384 bit RSA DKIM key configured at: dkim._domainkey.t-systems.nl

                                        384 bit RSA is... how shall I put it? I think 512 bit is the lowest RSA key size that was ever really used. 384 bit RSA is crackable in a few hours on a modern PC (using cado-nfs). The private key is:
                                        -----BEGIN RSA PRIVATE KEY-----
                                        MIHxAgEAAjEAtTliQYV2Xvx1OGkDyOL799BTFEuobY2dn2AgtiKCQgrh78NVK1JK
                                        j0yRXgNnPpGBAgMBAAECMF0t+TBZUCi8xATSMij7VLTxv5Xi5OIXesNiXOKtYIRP
                                        LkpYfR5PggaMScfbmqSssQIZAMwOhm9d7Y7Qi7I2j1AlYbiqdtqO54T7FQIZAONa
                                        9dJFkC6lM3EPXR+0SZ4dqwwpiM0nvQIYYgz8thi5JK264ohq9sTvnu9yKvUN9I09
                                        AhgfgMYZKcxtujRjkSZtMzUUNLYzzDmJe90CGDKwqcBI0v9ChaR8WHht+/chMdxj
                                        7ez94w==
                                        -----END RSA PRIVATE KEY-----

                                        yama@tech.lgbtY This user is from outside of this forum
                                        yama@tech.lgbtY This user is from outside of this forum
                                        yama@tech.lgbt
                                        wrote last edited by
                                        #49

                                        @badkeys RSA ?
                                        You can literally get an API key for your python script to access a literal quantum computer. And someone already made shors alg. implementation exclusively for RSA cracking

                                        If it were over 4096 bits its still Not Secure and crackable within seconds.
                                        Literally Any modern post quantum algorirthm is orders of magnitude better...

                                        varx@infosec.exchangeV 1 Reply Last reply
                                        0
                                        • badrihippo@fosstodon.orgB badrihippo@fosstodon.org

                                          @Diziet 😮 never even thought this could be a thing!

                                          So you're basically making it impossible to prove through DKIM signatures that a given email was actually sent from your server?

                                          @badkeys

                                          diziet@mastodon.me.ukD This user is from outside of this forum
                                          diziet@mastodon.me.ukD This user is from outside of this forum
                                          diziet@mastodon.me.uk
                                          wrote last edited by
                                          #50

                                          @badrihippo @badkeys Yes.

                                          Everyone should be doing the same (rotating DKIM keys and publishing the old private keys). Here's my blog post on the subject:

                                          https://diziet.dreamwidth.org/16025.html

                                          1 Reply Last reply
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