chore: add script to retrieve certificate fingerprint (#212)

* chore: add script to get certificate fingerprint

* chore: remove indent

package.json

@@ -15,7 +15,8 @@
     "lint": "tslint -c tslint.json --project .",
     "lint:tests": "tslint -c tslint.json 'test/**/*.test.ts'",
     "prettify": "yarn run prettier --config .prettierrc.js --write '**/*.+(ts|tsx|js|jsx|sol|java)'",
-    "prettify:diff": "yarn run prettier --config .prettierrc.js --list-different '**/*.+(ts|tsx|js|jsx|sol|java)'"
+    "prettify:diff": "yarn run prettier --config .prettierrc.js --list-different '**/*.+(ts|tsx|js|jsx|sol|java)'",
+    "get-cert": "./scripts/get_cert_fingerprint.sh"
   },
   "dependencies": {
     "@celo/connect": "1.5.2",

scripts/get_cert_fingerprint.sh

@@ -0,0 +1,52 @@
+#!/bin/bash
+
+# This script retrieves the intermediate certificate with the specified index
+# from the certificate chain of the specified server and computes its SHA-256
+# fingerprint.
+
+# The script requires the following arguments:
+#   - server_name: the name of the server to connect to
+#   - intermediate_cert_index: the index of the intermediate certificate to
+
+# The script can be run from the root directory of the project as follows:
+# yarn get-cert [server_name] [intermediate_cert_index]
+# yarn get-cert api-cloud.bitmart.com 1
+
+# Check if two arguments are provided
+if [ "$#" -ne 2 ]; then
+    echo "Usage: $0 <server_name> <intermediate_cert_index>"
+    exit 1
+fi
+
+SERVER_NAME=$1
+CERT_INDEX=$2
+
+# Retrieve the entire certificate chain and store it in an array
+mapfile -t CERT_CHAIN < <(echo | openssl s_client -servername $SERVER_NAME -connect $SERVER_NAME:443 -showcerts 2>/dev/null | sed -n '/-----BEGIN CERTIFICATE-----/,/-----END CERTIFICATE-----/p')
+
+# Check if the specified index is valid
+if [ "$CERT_INDEX" -lt 1 ] || [ "$CERT_INDEX" -gt "${#CERT_CHAIN[@]}" ]; then
+    echo "Invalid intermediate certificate index: $CERT_INDEX"
+    exit 2
+fi
+
+# Extract the specified intermediate certificate
+INTERMEDIATE_CERT=""
+for ((i=0; i<${#CERT_CHAIN[@]}; i++)); do
+    if [[ ${CERT_CHAIN[$i]} =~ 'BEGIN CERTIFICATE' ]]; then
+        let cert_count++
+    fi
+    if [ $cert_count -eq $CERT_INDEX ]; then
+        INTERMEDIATE_CERT+="${CERT_CHAIN[$i]}"$'\n'
+    fi
+done
+
+# Check if the intermediate certificate was found
+if [ -z "$INTERMEDIATE_CERT" ]; then
+    echo "Intermediate certificate with index $CERT_INDEX not found."
+    exit 3
+fi
+
+# Compute and display the SHA-256 fingerprint
+echo "$INTERMEDIATE_CERT" | openssl x509 -noout -fingerprint -sha256
+