From a3e5e42375968d7c9a4fe84969ebcb3627cdb3c4 Mon Sep 17 00:00:00 2001
From: Zhenchao Li <cockneykevin@gmail.com>
Date: Fri, 6 Aug 2010 21:57:13 +0800
Subject: [PATCH] add code to generate self signed certificates

---
 src/common/jingle_xtls.py | 91 ++++++++++++++++++++++++++++++++++++++-
 1 file changed, 90 insertions(+), 1 deletion(-)

diff --git a/src/common/jingle_xtls.py b/src/common/jingle_xtls.py
index 8fe6140e7..1b0e23d84 100644
--- a/src/common/jingle_xtls.py
+++ b/src/common/jingle_xtls.py
@@ -26,10 +26,14 @@ PYOPENSSL_PRESENT = False
 try:
     import OpenSSL
     PYOPENSSL_PRESENT = True
-    from OpenSSL import SSL, Context
 except ImportError:
     log.info("PyOpenSSL not available")
 
+if PYOPENSSL_PRESENT:
+    from OpenSSL import SSL
+    from OpenSSL.SSL import Context
+    from OpenSSL import crypto
+
 def default_callback(connection, certificate, error_num, depth, return_code):
     log.info("certificate: %s" % certificate)
     return return_code
@@ -54,3 +58,88 @@ def get_context(fingerprint, verify_cb=None):
         ctx.load_verify_locations(os.path.expanduser('~/certs/CA.cert'))
     return ctx
 
+# the following code is partly due to pyopenssl examples
+
+TYPE_RSA = crypto.TYPE_RSA
+TYPE_DSA = crypto.TYPE_DSA
+
+def createKeyPair(type, bits):
+    """
+    Create a public/private key pair.
+
+    Arguments: type - Key type, must be one of TYPE_RSA and TYPE_DSA
+               bits - Number of bits to use in the key
+    Returns:   The public/private key pair in a PKey object
+    """
+    pkey = crypto.PKey()
+    pkey.generate_key(type, bits)
+    return pkey
+
+def createCertRequest(pkey, digest="md5", **name):
+    """
+    Create a certificate request.
+
+    Arguments: pkey   - The key to associate with the request
+               digest - Digestion method to use for signing, default is md5
+               **name - The name of the subject of the request, possible
+                        arguments are:
+                          C     - Country name
+                          ST    - State or province name
+                          L     - Locality name
+                          O     - Organization name
+                          OU    - Organizational unit name
+                          CN    - Common name
+                          emailAddress - E-mail address
+    Returns:   The certificate request in an X509Req object
+    """
+    req = crypto.X509Req()
+    subj = req.get_subject()
+
+    for (key,value) in name.items():
+        setattr(subj, key, value)
+
+    req.set_pubkey(pkey)
+    req.sign(pkey, digest)
+    return req
+
+def createCertificate(req, (issuerCert, issuerKey), serial, (notBefore, notAfter), digest="md5"):
+    """
+    Generate a certificate given a certificate request.
+
+    Arguments: req        - Certificate reqeust to use
+               issuerCert - The certificate of the issuer
+               issuerKey  - The private key of the issuer
+               serial     - Serial number for the certificate
+               notBefore  - Timestamp (relative to now) when the certificate
+                            starts being valid
+               notAfter   - Timestamp (relative to now) when the certificate
+                            stops being valid
+               digest     - Digest method to use for signing, default is md5
+    Returns:   The signed certificate in an X509 object
+    """
+    cert = crypto.X509()
+    cert.set_serial_number(serial)
+    cert.gmtime_adj_notBefore(notBefore)
+    cert.gmtime_adj_notAfter(notAfter)
+    cert.set_issuer(issuerCert.get_subject())
+    cert.set_subject(req.get_subject())
+    cert.set_pubkey(req.get_pubkey())
+    cert.sign(issuerKey, digest)
+    return cert
+
+def make_certs(filepath, CN):
+    """
+    make self signed certificates
+    filepath : absolute path of certificate file, will be appended the '.pkey' and '.cert' extensions
+    CN : common name
+    """
+    key = createKeyPair(TYPE_RSA, 1024)
+    req = createCertRequest(key, CN=CN)
+    cert = createCertificate(req, (req, key), 0, (0, 60*60*24*365*5)) # five years
+    open(filepath + '.pkey', 'w').write(crypto.dump_privatekey(crypto.FILETYPE_PEM, key))
+    open(filepath + '.cert', 'w').write(crypto.dump_certificate(crypto.FILETYPE_PEM, cert))
+
+
+if __name__ == '__main__':
+    make_certs('./selfcert', 'gajim')
+