SHA-1 Hash for R-3.5.0.pkg Incorrect

On Apr 26, 2018, at 1:35 PM, Simon Urbanek <simon.urbanek at r-project.org> wrote:

Marc,

no, the hashes merely a legacy to check that you don't have a corrupted download. They are neither intended nor used for validation. To verify the validity you should use the signature check.

Cheers,
Simon

On Apr 25, 2018, at 4:37 PM, Marc Schwartz <marc_schwartz at me.com> wrote:

Hi Simon,

Thanks for the explanation.

It did not occur to me that SHA-0 was being used, since it was withdrawn as a standard circa early 90's, after significant flaws were identified.

Apple (and others) either have or are moving away from SHA-1 to SHA-2, at least for TLS/PKI security:

 https://support.apple.com/en-us/HT207459

recognizing the differences between session specific TLS/PKI trust uses and longer term file integrity checking. I know Linus is more "relaxed" regarding SHA-1 and the implications for Git, or at least was last year, albeit indicating a path away from it in time.

I guess the question boils down to, if we are going to provide hashes of the files under the premise that it should offer a high level of comfort to useRs that the file has not been modified/replaced since generation, presuming that the published hash value itself was not altered, I would put forth for further discussion, moving to SHA-2 and away from both MD5 and SHA-1 (certainly moving away from SHA-0), depending upon a more broad assessment of the implications of doing so.

Thanks!

Marc

On Apr 25, 2018, at 2:54 PM, Simon Urbanek <simon.urbanek at R-project.org> wrote:

Marc,

thanks, the issue is:

hagal:R-3.5.0$ openssl sha R-3.5.0-el-capitan-signed.pkg
SHA(R-3.5.0-el-capitan-signed.pkg)= 9f5f3365afee54d3fe3148a60c1405955916f076

hagal:R-3.5.0$ openssl sha1 R-3.5.0-el-capitan-signed.pkg
SHA1(R-3.5.0-el-capitan-signed.pkg)= 6e90d38892bb366630ae30c223a898e8af84dff7

so either we change the label to SHA (or SHA-0?) or change the checksum. In the root we actually provide both, even if that may or may not be relevant. For now I did the latter in the index.html.

Cheers,
Simon

On Apr 25, 2018, at 7:57 AM, Marc Schwartz <marc_schwartz at me.com> wrote:

Hi All,

Last month:

https://stat.ethz.ch/pipermail/r-sig-mac/2018-March/012691.html

there was a report that the SHA-1 hash of the R-3.4.4.pkg, as listed on CRAN, was not correct, even though the MD5 hash and the digital signature appeared to be correct.

The same phenomenon is the case with R-3.5.0.pkg.

The MD5 hash on CRAN is:

MD5-hash: 414029c9c9f706d3d04baa887ccffbc4 

and I get:

md5 R-3.5.0.pkg
MD5 (R-3.5.0.pkg) = 414029c9c9f706d3d04baa887ccffbc4

from the CLI on my Mac.

However, the SHA-1 hash on CRAN is:

SHA-hash: 9f5f3365afee54d3fe3148a60c1405955916f076 

and I get:

shasum R-3.5.0.pkg
6e90d38892bb366630ae30c223a898e8af84dff7  R-3.5.0.pkg

from the CLI on my Mac.

It would seem that there is a lingering issue with the generation of the SHA-1 hash value on CRAN.

Thanks,

Marc Schwartz