OpenPGP Message Format (RFC 4880) well defines key structure and wire formats (openpgp packets). Thus when I looked for public key network (SKS) server setup, I quickly found pointers to dump files in said format for bootstrapping a key server.
I did not feel like experimenting with Python and instead opted for Go and found http://code.google.com/p/go.crypto/openpgp/packet library that has comprehensive support for parsing openpgp low level structures. I've downloaded the SKS dump, verified it's MD5SUM hashes (lolz), and went ahead to process them in Go.
With help from http://github.com/lib/pq and database/sql, I've written a small program to churn through all the dump files, filter for primary RSA keys (not subkeys) and inject them into a database table. The things that I have chosen to inject are fingerprint, N, E. N & E are the modulus of the RSA key pair and the public exponent. Together they form a public part of an RSA keypair. So far, nothing fancy.
Next I've run an SQL query to see how unique things are... and found 92 unique N & E pairs that have from two and up to fifteen duplicates. In total it is 231 unique fingerprints, which use key material with a known duplicate in the public key network. That didn't sound good. And also odd - given that over 940 000 other RSA keys managed to get unique enough entropy to pull out a unique key out of the keyspace haystack (which is humongously huge by the way).
Having the list of the keys, I've fetched them and they do not look like regular keys - their UIDs do not have names & emails, instead they look like something from the monkeysphere. The keys look like they are originally used for TLS and/or SSH authentication, but were converted into OpenPGP format and uploaded into the public key server. This reminded me of the Debian's SSL key generation vulnerability CVE-2008-0166. So these keys might have been generated with bad entropy due to affected tools by that CVE and later converted to OpenPGP.
Looking at the openssl-blacklist package, it should be relatively easy for me to generate all possible RSA key-pairs and I believe all other material that is hashed to generate the fingerprint are also available (RFC 4880#12.2). Thus it should be reasonably possible to generate matching private keys, generate revocation certificates and publish the revocation certificate with pointers to CVE-2008-0166. (Or email it to the people who have signed given monkeysphered keys). When I have a minute I will work on generating openpgp-blacklist type of scripts to address this.
If anyone is interested in the Go source code I've written to process openpgp packets, please drop me a line and I'll publish it on github or something.
I did not feel like experimenting with Python and instead opted for Go and found http://code.google.com/p/go.crypto/openpgp/packet library that has comprehensive support for parsing openpgp low level structures. I've downloaded the SKS dump, verified it's MD5SUM hashes (lolz), and went ahead to process them in Go.
With help from http://github.com/lib/pq and database/sql, I've written a small program to churn through all the dump files, filter for primary RSA keys (not subkeys) and inject them into a database table. The things that I have chosen to inject are fingerprint, N, E. N & E are the modulus of the RSA key pair and the public exponent. Together they form a public part of an RSA keypair. So far, nothing fancy.
Next I've run an SQL query to see how unique things are... and found 92 unique N & E pairs that have from two and up to fifteen duplicates. In total it is 231 unique fingerprints, which use key material with a known duplicate in the public key network. That didn't sound good. And also odd - given that over 940 000 other RSA keys managed to get unique enough entropy to pull out a unique key out of the keyspace haystack (which is humongously huge by the way).
Having the list of the keys, I've fetched them and they do not look like regular keys - their UIDs do not have names & emails, instead they look like something from the monkeysphere. The keys look like they are originally used for TLS and/or SSH authentication, but were converted into OpenPGP format and uploaded into the public key server. This reminded me of the Debian's SSL key generation vulnerability CVE-2008-0166. So these keys might have been generated with bad entropy due to affected tools by that CVE and later converted to OpenPGP.
Looking at the openssl-blacklist package, it should be relatively easy for me to generate all possible RSA key-pairs and I believe all other material that is hashed to generate the fingerprint are also available (RFC 4880#12.2). Thus it should be reasonably possible to generate matching private keys, generate revocation certificates and publish the revocation certificate with pointers to CVE-2008-0166. (Or email it to the people who have signed given monkeysphered keys). When I have a minute I will work on generating openpgp-blacklist type of scripts to address this.
If anyone is interested in the Go source code I've written to process openpgp packets, please drop me a line and I'll publish it on github or something.
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