# Local Registry RSA key Problem

**URL:** <https://discourse.julialang.org/t/local-registry-rsa-key-problem/78188>\
**Category:** Tooling\
**Tags:** registry, local\
**Created:** [March 21, 2022, 3:18am UTC](https://discourse.julialang.org/t/local-registry-rsa-key-problem/78188 "2022-03-21T03:18:38Z")\
**Posts on this page:** 1\
**Showing post:** 4

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**Author:** ![GunnarFarneback](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/gunnarfarneback/32/1827_2.png) [@GunnarFarneback](https://discourse.julialang.org/u/GunnarFarneback)\
**Post date:** [March 21, 2022, 8:55am UTC](https://discourse.julialang.org/t/local-registry-rsa-key-problem/78188/4 "2022-03-21T08:55:05Z")

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I can expand on this.

1. `JULIA_PKG_USE_CLI_GIT` is the preferred solution and documented in [https://github.com/GunnarFarneback/LocalRegistry.jl/blob/master/docs/ssh\_keys.md#2-using-an-external-git-binary-with-julias-package-manager](https://github.com/GunnarFarneback/LocalRegistry.jl/blob/master/docs/ssh_keys.md#2-using-an-external-git-binary-with-julias-package-manager). The main limitation is that it’s only available from Julia 1.7 and, obviously, requires an external `git` installation.
2. `ssh-keygen -t rsa -b 4096 -m PEM` still generates a key which Julia Pkg can use with `libgit2`/`libssh2`. However, GitHub will not accept the key, but if you’re using it with other git services they may be more accepting.
3. There is **no** other key type that can be used with existing Julia binary downloads through `libgit2`/`libssh2`. Although version 1.9.0 of `libssh2` does support ECDSA keys, that requires a specific crypto backend, which is not the one Julia is built with.
4. If you build Julia yourself, it should be possible to configure it so that `libssh2` understands ECDSA keys.
5. `libssh2` ~~master~~ 1.10.0 contains support for ECDSA keys with the `mbedtls` backend, which Julia uses, assuming everything is built with the appropriate feature enabled. ~~This may eventually make its way into Julia’s binary downloads.~~ This will be available for Julia 1.8 and later (and is already available in Julia 1.8-beta1). You may want to set the environment variable `SSH_KEY_PATH` to point to your ECDSA key.
6. If you do try to use a non-RSA key with Julia you will get repeatedly prompted for the key location. The first time this is because it indeed doesn’t know where the key is (unless you have told it with `SSH_KEY_PATH` and `SSH_PUB_KEY_PATH`) but all the following times it is because `libssh2` hasn’t been built with support for reading the key. Yes, this is a very unhelpful behavior and you can only find out what’s going on by [patching `libssh2`](https://github.com/JuliaLang/Pkg.jl/issues/1516#issuecomment-560794389).
7. See item 1. ~~There’s a possibility that this option could be backported to a future 1.6.x release~~. This has been backported and will be available in Julia 1.6.6.

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