Problem with replacing a string with SSL cetificate content

February 14, 2022

I have a requirement to replace a string in a file with below certificate content and it needs to be in this format. I am unable to do this with sed in bash.

"-----BEGIN CERTIFICATE-----/r/n"
"MIIDazCCAlOgAwIBAgIUb14HAcAizLZ3jFxFhAQHLdsCWI0wDQYJKoZIhvcNAQEL/r/n"
"BQAwRTELMAkGA1UEBhMCQVUxEzARBgNVBAgMClNvbWUtU3RhdGUxITAfBgNVBAoM/r/n"
"GEludGVybmV0IFdpZGdpdHMgUHR5IEx0ZDAeFw0yMjAyMTQxNzAxMTBaFw0yNzAy/r/n"
"MTMxNzAxMTBaMEUxCzAJBgNVBAYTAkFVMRMwEQYDVQQIDApTb21lLVN0YXRlMSEw/r/n"
"HwYDVQQKDBhJbnRlcm5ldCBXaWRnaXRzIFB0eSBMdGQwggEiMA0GCSqGSIb3DQEB/r/n"
"AQUAA4IBDwAwggEKAoIBAQC55VnblFue90NYNhz15aQBWsZ5FC6EXZibiHwKnE13/r/n"
"j0pCDxrY6oxia6Zz7pZcFyRYrQ4Gd/nconYs5lreijxErG30HgX+owdYeW1sdhTW/r/n"
"xyA1hGPQFmMAxs29+5siiZz08QRrEuKDsYqvqQa0Zqrw0hqNVD5Vu74y0U8k12Y0/r/n"
"7kCxQ1GbkZJ4hsVaMOvbIl061f+Uk6McUKraXdM45AsgBGZFBVuzrR3QeAnvuIXH/r/n"
"9sMi4vpzBQI1RGaZME1jn4nE5Gy3KM4tn99h4of5ei78iViNoB1ww9orYz2xqnKn/r/n"
"HT0Z+m0X94RzAXXAxBW/a7TC8miNn3b3c4hUx/J7rXq3AgMBAAGjUzBRMB0GA1Ud/r/n"
"DgQWBBQisnLWumDdji5PGyhgpz+NjNst8jAfBgNVHSMEGDAWgBQisnLWumDdji5P/r/n"
"Gyhgpz+NjNst8jAPBgNVHRMBAf8EBTADAQH/MA0GCSqGSIb3DQEBCwUAA4IBAQBi/r/n"
"O4cYreKRE+xHprpcBNC3MZh/N1W1rbyAZgoJ3Rg1LkAfjK3gWyu++kEEJ7kENkyS/r/n"
"YaVhJ9lESwLIzhTwnk4ssu0aGtlW2jRktA2yAwaeqbAMbYKdNVGGR/KtXKufM4O6/r/n"
"CKDSyNCxkpyx1j1bOAkv3XUYLfFo9Ze1eGGOltgWvwfogLhGoH+xTk+LImyBHBE1/r/n"
"5WtfhV0B1+V1hxX1uAuuzleiOfCJnGnSny+9EaQNtTuoo20te1VJbkzh11gIQvoc/r/n"
"pOMSjWAZSSsK/gEI8rpDZwCR34FJM4iMoiYvFnBdwLX1wxXfKyEqfyQtD9nwKt4J/r/n"
"DyOZAEmx+0JxTALodX3V/r/n"
"-----END CERTIFICATE-----/r/n"

I stored this into a variable like below and trying to replace using sed command like below.

export mycert=$(cat mycert.pem)
sed "s/DUMMY/$mycert/g" testfile

I get the errors like below:
sed: -e expression #1, char 37: unknown option to `s’

sed: -e expression #1, char 39: unterminated `s’ command

I tried almost all combinations I know. No luck

>Solution :

Using GNU sed:

mycert=$(sed '$!s/$/\\/' mycert.perm)
sed "s=DUMMY=$mycert=" testfile

Use sed to escape new lines in the replacement, except the last, which is stripped by the command sub.
These will be used in the replacement string (because they are escaped).
Change the delimiter to =, which doesn’t conflict.