+
+/** @param key RSA private key in PEM format (optionally with -----BEGIN... / -----END...)
+ * @return SHA1 fingerprint of key
+ */
+string
+dcp::private_key_fingerprint (string key)
+{
+ boost::replace_all (key, "-----BEGIN RSA PRIVATE KEY-----\n", "");
+ boost::replace_all (key, "\n-----END RSA PRIVATE KEY-----\n", "");
+
+ unsigned char buffer[4096];
+ int const N = base64_decode (key, buffer, sizeof (buffer));
+
+ SHA_CTX sha;
+ SHA1_Init (&sha);
+ SHA1_Update (&sha, buffer, N);
+ uint8_t digest[20];
+ SHA1_Final (digest, &sha);
+
+ char digest_base64[64];
+ return Kumu::base64encode (digest, 20, digest_base64, 64);
+}