Merge the logic at master...eregon:openssl-linux

See:
#1974 (review)
master...eregon:openssl-linux
rubygems/rubygems#2415 (comment)

Author: znz

bin/ruby-build

@@ -1150,14 +1150,27 @@ build_package_openssl() {
     local pem_file="$OPENSSLDIR/cert.pem"
     security find-certificate -a -p /Library/Keychains/System.keychain > "$pem_file"
     security find-certificate -a -p /System/Library/Keychains/SystemRootCertificates.keychain >> "$pem_file"
-  else
+  elif [ -e /etc/pki/tls/cert.pem ]; then # RedHat
+    # See https://github.com/rubygems/rubygems/issues/2415#issuecomment-509806259
+    rm -rf "$OPENSSLDIR/certs" "$pem_file"
+    ln -s /etc/pki/tls/certs "$OPENSSLDIR"
+    ln -s /etc/pki/tls/cert.pem "$pem_file"
+  elif [ -e /etc/ssl/certs/ca-certificates.crt ]; then # Debian
+    # See https://github.com/rubygems/rubygems/issues/2415#issuecomment-509806259
+    rm -rf "$OPENSSLDIR/certs" "$pem_file"
+    ln -s /etc/ssl/certs "$OPENSSLDIR"
+    ln -s /etc/ssl/certs/ca-certificates.crt "$pem_file"
+  elif type openssl &>/dev/null; then
     # symlink to the system openssl certs
     local SYSTEM_OPENSSLDIR
     SYSTEM_OPENSSLDIR=$(openssl version -d | sed -e 's/.*: "//' -e 's/"$//' || true)
     if [ -n "$SYSTEM_OPENSSLDIR" ]; then
       ln -sf "$SYSTEM_OPENSSLDIR/cert.pem" "$OPENSSLDIR/cert.pem"
       ln -snf "$SYSTEM_OPENSSLDIR/certs" "$OPENSSLDIR/certs"
     fi
+  else
+    echo "Could not find OpenSSL certificates" >&2
+    exit 1
   fi
 }