PKCS#1 implementation improved

1 files changed, 62 insertions, 0 deletions

diff --git a/tools/pkcs1dump.py b/tools/pkcs1dump.py
new file mode 100644
index 0000000..c7a4189
--- /dev/null
+++ b/tools/pkcs1dump.py
@@ -0,0 +1,62 @@
+# Read unencrypted PKCS#1/PKIX-compliant, PEM&DER encoded private keys on
+# stdin, print them pretty and encode back into original wire format.
+# Private keys can be generated with "openssl genrsa|gendsa" commands.
+import sys, base64
+from pyasn1_modules import rfc2459, rfc2437
+from pyasn1.codec.der import encoder, decoder
+
+keyMagic = {
+    '-----BEGIN DSA PRIVATE KEY-----':
+    {'-----END DSA PRIVATE KEY-----': rfc2459.DSAPrivateKey() },
+    '-----BEGIN RSA PRIVATE KEY-----':
+    {'-----END RSA PRIVATE KEY-----': rfc2437.RSAPrivateKey() }
+    }
+
+# Read PEM keys from stdin and print them out in plain text
+
+if len(sys.argv) != 1:
+    print("""Usage:
+$ openssl genrsa -out /tmp/myprivatekey.pem
+$ cat /tmp/myprivatekey.pem | %s""" % sys.argv[0])
+    sys.exit(-1)
+                                
+stSpam, stHam, stDump = 0, 1, 2
+state = stSpam
+keyCnt = 0
+
+for keyLine in sys.stdin.readlines():
+    keyLine = keyLine.strip()
+    if state == stSpam:
+        if keyLine in keyMagic:
+            keyMagicTail = keyMagic[keyLine]
+            keyLines = []
+            state = stHam
+            continue
+    if state == stHam:
+        if keyLine in keyMagicTail:
+            asn1Spec = keyMagicTail[keyLine]
+            state = stDump
+        else:
+            keyLines.append(keyLine.encode())
+    if state == stDump:
+        substrate = ''.encode()
+        try:
+            for keyLine in keyLines:
+                substrate = substrate + base64.decodestring(keyLine)
+        except TypeError:
+            print('%s, possibly encrypted key' % (sys.exc_info()[1], ))
+            state = stSpam
+            continue
+
+        key, rest = decoder.decode(substrate, asn1Spec=asn1Spec)
+
+        if rest: substrate = substrate[:-len(rest)]
+        
+        print(key.prettyPrint())
+        
+        assert encoder.encode(key) == substrate, 'key re-code fails'
+        
+        keyCnt = keyCnt + 1
+        state = stSpam
+
+print('*** %s private key(s) re/serialized' % keyCnt)