Unable to proceed with installation under proxy due to SSL error on Ubuntu

[nascarsayan]

I am trying to install rust and related tools using the script curl https://sh.rustup.rs -sSf | sh. However, I get the error :

error: could not download file from 'https://static.rust-lang.org/dist/channel-rust-stable.toml.sha256' to '/home/nascarsayan/.rustup/tmp/vnx5fmfc21kuqttu_file'
info: caused by: error during download
info: caused by: [35] SSL connect error (error:140770FC:SSL routines:SSL23_GET_SERVER_HELLO:unknown protocol)

Other installation methods including building from source don't work and give the same error.

[samfux84]

Similar problem here:

Submodules updated in 68.38 seconds
curl: (35) error:140770FC:SSL routines:SSL23_GET_SERVER_HELLO:unknown protocol

spurious failure, trying again
curl: (35) error:140770FC:SSL routines:SSL23_GET_SERVER_HELLO:unknown protocol

spurious failure, trying again
curl: (35) error:140770FC:SSL routines:SSL23_GET_SERVER_HELLO:unknown protocol

spurious failure, trying again
curl: (35) error:140770FC:SSL routines:SSL23_GET_SERVER_HELLO:unknown protocol

spurious failure, trying again
curl: (35) error:140770FC:SSL routines:SSL23_GET_SERVER_HELLO:unknown protocol
failed to run: curl -s -y 30 -Y 10 --connect-timeout 30 --retry 3 -Sf -o /scratch/87971386.tmpdir/tmpRwGdZx.sha256 https://static.rust-lang.org/dist/2019-01-17/rust-std-1.32.0-x86_64-unknown-linux-gnu.tar.gz.sha256
Build completed unsuccessfully in 0:01:08
make: *** [Makefile:18: all] Error 1