Bash special character used in YAML file - bash

Question

I am struggling with some bash script that generates some Environment Variables for me. I am using it in .travis.yml file later.
My encrypted key looks like that:
someRandomCharacters
withNewLine
In Terminal I checked three possibilities.
echo "someRandomCharacters
withNewLine" | openssl enc -aes-128-cbc -a -salt -pass pass:SomePassword -base64 -d
and
echo "someRandomCharacters\nWithNewLine" | openssl enc -aes-128-cbc -a -salt -pass pass:SomePassword -base64 -d
will give me correct output.
echo "someRandomCharactersWithNewLine" | openssl enc -aes-128-cbc -a -salt -pass pass:SomePassword -base64 -d
This one above will return error reading input file
So far so good - I understand why it works like that. But when I try to enter any of abovementioned options - for example like that:
- SOME_ENV=`echo "someRandomCharacters\nWithNewLines" | openssl enc -aes 128-cbc -a -salt -pass pass:SomePassword -base64 -d`
into travis.yml, two last options will return error reading input file and the first one will crash the whole build due to incorrect .yaml syntax.
I've tried to use any of these three above + many more for example with "\n" as special character as I found in examples here on STO. Any of them would return error reading input file and none of them returned me decrypted SOME_ENV into travis. Is there any solution for that? Or maybe my poor experience with BASH and YAML blocks me for seeing obvious mistake?

Answer 1

While it's hard to tell what exactly the problem is given fake data, here are some data points:
dash (the shell you get if you just run sh on modern Linux distros) and bash behave differently in certain cases.
You should never assume that a code snippet runs with bash, because any number of reasons can cause it to be run with sh instead, and it's sometimes hard to tell.
Here's a script containing a \n sequence that works with sh but fails with bash:
$ cat myfile
echo "U2FsdGVkX19EB+D8no\n9+9bnl4dE5H2WbOUSvsGZjK7s=" | openssl enc -aes-128-cbc -a -salt -pass pass:MyPassword -base64 -d
$ sh myfile
My test data
$ bash myfile
error reading input file
If we instead use echo -e, we get the opposite result where dash fails and bash works:
$ cat myfile
echo -e "U2FsdGVkX19EB+D8no\n9+9bnl4dE5H2WbOUSvsGZjK7s=" | openssl enc -aes-128-cbc -a -salt -pass pass:MyPassword -base64 -d
$ sh myfile
error reading input file
$ bash myfile
My test data
This is why POSIX recommends not using echo. If we instead use printf, it works on both:
$ cat myfile
printf "U2FsdGVkX19EB+D8no\n9+9bnl4dE5H2WbOUSvsGZjK7s=\n" | openssl enc -aes-128-cbc -a -salt -pass pass:MyPassword -base64 -d
$ sh myfile
My test data
$ bash myfile
My test data
However, the line feed sequence in the middle is optional for openssl, and can just be removed (even though you seem to say that this doesn't work: maybe you removed the \ but not the n?)
$ cat myfile
echo "U2FsdGVkX19EB+D8no9+9bnl4dE5H2WbOUSvsGZjK7s=" | openssl enc -aes-128-cbc -a -salt -pass pass:MyPassword -base64 -d
$ sh myfile
My test data
$ bash myfile
My test data