diff --git a/common/src/utils/certificates.ts b/common/src/utils/certificates.ts
index b4bd69cc..7d6544d0 100644
--- a/common/src/utils/certificates.ts
+++ b/common/src/utils/certificates.ts
@@ -54,7 +54,7 @@ export function getPublicKey(certificate) {
     throw new Error("Unable to extract public key");
 }
 
-function extractModulus(publicKeyInfo: string): string | null {
+export function extractModulus(publicKeyInfo: string): string | null {
     // RSA OID
     const rsaOid = '2a864886f70d010101';
     // RSA-PSS OID
diff --git a/common/test/certificates.test.ts b/common/test/certificates.test.ts
new file mode 100644
index 00000000..d9a2d97e
--- /dev/null
+++ b/common/test/certificates.test.ts
@@ -0,0 +1,49 @@
+import { assert, expect } from 'chai'
+import path from "path";
+import { readCertificate, getPublicKey, extractModulus } from "../src/utils/certificates";
+
+describe("Certificates (sha256_rsa_2048)", function () {
+    const cert = readCertificate("src/mock_certificates/sha256_rsa_2048/mock_csca.crt");
+
+    it("should get public key from certificate", async function () {
+        const publicKey = getPublicKey(cert);
+        expect(publicKey.type, "should be RSA").to.equal("RSA");
+        expect(publicKey.n.bitLength(), "should be 2048").to.equal(2048);
+        expect(publicKey.e.toString(), "should be 65537").to.equal("65537");
+    });
+
+    it("should extract modulus from certificate", async function () {
+        const publicKeyInfo = cert.getPublicKeyHex();
+        const modulus = extractModulus(publicKeyInfo);
+        expect(modulus, "should not be null").to.not.be.null;
+        expect(modulus.length, "should be 512").to.equal(260);
+        expect(modulus, "should be equal").to.equal(
+            "010100ab5919e1a521f03ef9fae6752e2ee18b4f860638e229fe7e0db738bf0ebd31b30599462d" + 
+            "84df307a0eb300aeda7db9a9029738cc867e52cb68d72c4a9da9171b5a5847a6e228a0bf128ba7" +
+            "32d28fd2bbdb8c8df59c7b053fb73c2203762f58a43ee1dcf034b6156b255c3a37d90f7ead439f" +
+            "532a2fa49591c4e08d8b53db34");
+    });
+});
+
+describe("Certificates (sha1_rsa_2048)", function () {
+    const cert = readCertificate("src/mock_certificates/sha1_rsa_2048/mock_csca.crt");
+
+    it("should get public key from certificate", async function () {
+        const publicKey = getPublicKey(cert);
+        expect(publicKey.type, "should be RSA").to.equal("RSA");
+        expect(publicKey.n.bitLength(), "should be 2048").to.equal(2048);
+        expect(publicKey.e.toString(), "should be 65537").to.equal("65537");
+    });
+
+    it("should extract modulus from certificate", async function () {
+        const publicKeyInfo = cert.getPublicKeyHex();
+        const modulus = extractModulus(publicKeyInfo);
+        expect(modulus, "should not be null").to.not.be.null;
+        expect(modulus.length, "should be 512").to.equal(260);
+        expect(modulus, "should be equal").to.equal(
+            "010100993920f4bccf753b0580e2fab971c218cca5be8e375c3e41a5d20e3799c115fc7eb4ac42d" +
+            "f4007e352406c905bf240d8d455d03df984eb744e7d4d16f68321f2fbbf9fec82276d85e31aa038" +
+            "0d35d9c5f0984c1ae80f1dc5e3aac6ff7674176d3795e97049dee45235ab3082091a2843994c1a2" +
+            "92218988f55f5db2053e054");
+    });
+});