Create a SignatureValue from a DigestValue

In this example, encrypted private key and X.509 are hard-coded in "PEM" form. You could use the filenames instead. (Actually, you don't need the certificate to do the signing, but we keep it here for completeness.) The default RSA-SHA-1 signature algorithm is used.

Updated 2021-08-27 for Python 3 (added parentheses to print statements: ``print foo``-->``print(foo)``, otherwise no other changes). Thanks to Bledar (Tirana Tirana) for pointing this out.

import cryptosyspki as pki

######################
# HARD-CODED PKI STUFF
######################
# Alice's PKCS8 encrypted key and X.509 certificate
# from RFC 4134 "Examples of S/MIME Messages"
# Private key password is "password"
myprikey = '''-----BEGIN ENCRYPTED PRIVATE KEY-----
MIICojAcBgoqhkiG9w0BDAEDMA4ECFleZ90vhGrRAgIEAASCAoA9rti16XVH
K4AJVe1CNf61NIpIogu/Xs4Yn4hXflvewiOwe6/9FkxBXLbhKdbQWn1Z4p3C
njVns2VYEO/qpJR3LciHMwp5dsqedUVVia//CqFHtEV9WfvCKWgmlkkT1YEm
1aChZnPP5i6IhwVT9qvFluTZhvVmjW0YyF86OrOp0uxxVic7phPbnPrOMelf
ZPc3A3EGpzDPkxN+o0obw87tUgCL+s0KtUOr3c6Si4KQ3IQjrjZxQF4Se3t/
4PEpqUl5EpYiCx9q5uqb0Lr1kWiiQ5/inZm5ETc+qO+ENcp0KjnX523CATYd
U5iOjl/X9XZeJrMpOCXogEuhmLPRauYP1HEWnAY/hLW93v10QJXY6ALlbkL0
sd5WU8Ces7T04b/p4/12yxqYqV68QePyfHpegdraDq3vRfopSwrUxtL9cisP
jsQcJ5FL/SfloFbmld4CKIjMsromsEWqo6rfo3JqNizgTVIIWExy3jDT9VvK
d9ADH0g3JCbuFzaWVOZMmZ0wlo28PKkLQ8FkW8CG/Lq/Q/bHLPM+sPdLN+ke
gpA6fvL4wpku4ST7hmeN1vWbRLlCfuFijux77hdM7knO9/MawICsA4XdzR78
p0C2hJlc6p46IWZaINQXGstTbJMh+mJ7i1lrbG2kvZ2Twf9R+RaLp2mPHjb1
+P+3f2L3tOoC31oJ18u/L1MXEWxLEZHB0+ANg+N/0/icwImcI0D+wVN2puU4
m58j81sGZUEAB3aFEbPxoX3y+qYlOnt1OfdY7WnNdyr9ZzI09fkrTvujF4LU
nycqE+MXerf0PxkNu1qv9bQvCoH8x3J2EVdMxPBtH1Fb7SbE66cNyh//qzZo
B9Je
-----END ENCRYPTED PRIVATE KEY-----
'''

mycert = '''-----BEGIN CERTIFICATE-----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-----END CERTIFICATE-----
'''

def sign_digest(digval, prikey, password):
    """Create base64-encoded SignatureValue from DigestValue.

    Args:
        digval (str): Digest value in base64 encoding to be signed.
        prikey (str): Either filename of private key file or key in PEM string format.
        password (str): Password for private key, if encrypted.

    Returns:
        str: Signature value in base64 encoding.
    """
    sigval = pki.Sig.sign_digest(pki.Cnv.frombase64(digval), prikey, password, pki.Sig.Alg.RSA_SHA1)
    return sigval


def main():
    # Sign digest of canonicalized SignedInfo
    print(sign_digest("oloG0znWi2Jc1zg6kyNXiJlWpU4=", myprikey, "password"))
    print(sign_digest("WsjvqwRamkb+ABrFjCU2Rv+I3Go=", myprikey, "password"))

TSQUoVrQ0kg1eiltNwIhKPrIdsi1VhWjYNJlXvfQqW2EKk3X37X862SCfrz7v8IYJ7OorWwlFpGDStJDSR6saOScqSvmesCrGEEq+U6zegR9nH0lvcGZ8Rvc/y7U9kZrE4fHqEiLyfpmzJyPmWUT9Uta14nPJYsl3cmdThHB8Bs=
nihUFQg4mDhLgecvhIcKb9Gz8VRTOlw+adiZOBBXgK4JodEe5aFfCqm8WcRIT8GLLXSk8PsUP4//SsKqUBQkpotcAqQAhtz2v9kCWdoUDnAOtFZkd/CnsZ1sge0ndha40wWDV+nOWyJxkYgicvB8POYtSmldLLepPGMz+J7/Uws=

The Python interface to CryptoSys PKI Pro is available separately here.

using System;
using System.Text;
using System.Diagnostics;
using CryptoSysPKI;

namespace SignDigest
{
    class SigValFromDigVal {
        // Alice's PKCS8 encrypted key and X.509 certificate
        // from RFC 4134 "Examples of S/MIME Messages"
        // Private key password is "password"
        const string myprikey = @"-----BEGIN ENCRYPTED PRIVATE KEY-----
            MIICojAcBgoqhkiG9w0BDAEDMA4ECFleZ90vhGrRAgIEAASCAoA9rti16XVH
            K4AJVe1CNf61NIpIogu/Xs4Yn4hXflvewiOwe6/9FkxBXLbhKdbQWn1Z4p3C
            njVns2VYEO/qpJR3LciHMwp5dsqedUVVia//CqFHtEV9WfvCKWgmlkkT1YEm
            1aChZnPP5i6IhwVT9qvFluTZhvVmjW0YyF86OrOp0uxxVic7phPbnPrOMelf
            ZPc3A3EGpzDPkxN+o0obw87tUgCL+s0KtUOr3c6Si4KQ3IQjrjZxQF4Se3t/
            4PEpqUl5EpYiCx9q5uqb0Lr1kWiiQ5/inZm5ETc+qO+ENcp0KjnX523CATYd
            U5iOjl/X9XZeJrMpOCXogEuhmLPRauYP1HEWnAY/hLW93v10QJXY6ALlbkL0
            sd5WU8Ces7T04b/p4/12yxqYqV68QePyfHpegdraDq3vRfopSwrUxtL9cisP
            jsQcJ5FL/SfloFbmld4CKIjMsromsEWqo6rfo3JqNizgTVIIWExy3jDT9VvK
            d9ADH0g3JCbuFzaWVOZMmZ0wlo28PKkLQ8FkW8CG/Lq/Q/bHLPM+sPdLN+ke
            gpA6fvL4wpku4ST7hmeN1vWbRLlCfuFijux77hdM7knO9/MawICsA4XdzR78
            p0C2hJlc6p46IWZaINQXGstTbJMh+mJ7i1lrbG2kvZ2Twf9R+RaLp2mPHjb1
            +P+3f2L3tOoC31oJ18u/L1MXEWxLEZHB0+ANg+N/0/icwImcI0D+wVN2puU4
            m58j81sGZUEAB3aFEbPxoX3y+qYlOnt1OfdY7WnNdyr9ZzI09fkrTvujF4LU
            nycqE+MXerf0PxkNu1qv9bQvCoH8x3J2EVdMxPBtH1Fb7SbE66cNyh//qzZo
            B9Je
            -----END ENCRYPTED PRIVATE KEY-----
            ";
        /// <summary>
        /// Create base64-encoded SignatureValue from DigestValue.
        /// </summary>
        /// <param name="digVal">Digest value in base64 encoding to be signed.</param>
        /// <param name="priKey">Either filename of private key file or key in PEM string format.</param>
        /// <param name="password">Password for private key, if encrypted.</param>
        /// <returns>Signature value in base64 encoding or empty string <c>""</c> on error.</returns>
        public static string SignDigest(string digVal, string priKey, string password)
        {
            string sigVal;
            sigVal = Sig.SignDigest(Cnv.FromBase64(digVal), priKey, password, SigAlgorithm.Rsa_Sha1);
            return sigVal;
        }
        static void Main(string[] args)
        {
            string sigVal;
            Console.WriteLine("PKI Version={0}", General.Version());    // At least 110200
            sigVal = SignDigest("oloG0znWi2Jc1zg6kyNXiJlWpU4=", myprikey, "password");
            Debug.Assert(sigVal.Length > 0);
            Console.WriteLine(sigVal);
            sigVal = SignDigest("WsjvqwRamkb+ABrFjCU2Rv+I3Go=", myprikey, "password");
            Debug.Assert(sigVal.Length > 0);
            Console.WriteLine(sigVal);
        }
    }
}

PKI Version=110200
TSQUoVrQ0kg1eiltNwIhKPrIdsi1VhWjYNJlXvfQqW2EKk3X37X862SCfrz7v8IYJ7OorWwlFpGDStJDSR6saOScqSvmesCrGEEq+U6zegR9nH0lvcGZ8Rvc/y7U9kZrE4fHqEiLyfpmzJyPmWUT9Uta14nPJYsl3cmdThHB8Bs=
nihUFQg4mDhLgecvhIcKb9Gz8VRTOlw+adiZOBBXgK4JodEe5aFfCqm8WcRIT8GLLXSk8PsUP4//SsKqUBQkpotcAqQAhtz2v9kCWdoUDnAOtFZkd/CnsZ1sge0ndha40wWDV+nOWyJxkYgicvB8POYtSmldLLepPGMz+J7/Uws=