Add unittests for the detection of md[2,4,5] when verifying certificates

net/data/ssl/certificates/weak_digest_md2_intermediate.pem

Index: net/data/ssl/certificates/weak_digest_md2_intermediate.pem
diff --git a/net/data/ssl/certificates/weak_digest_md2_intermediate.pem b/net/data/ssl/certificates/weak_digest_md2_intermediate.pem
new file mode 100644
index 0000000000000000000000000000000000000000..2f2765d02c0a61b14180a210a50c01a6f7423076
--- /dev/null
+++ b/net/data/ssl/certificates/weak_digest_md2_intermediate.pem
@@ -0,0 +1,57 @@
+Certificate:
+    Data:
+        Version: 3 (0x2)
+        Serial Number: 4 (0x4)
+        Signature Algorithm: md2WithRSAEncryption
+        Issuer: CN=Test Deprecated Digest Root CA
+        Validity
+            Not Before: Oct 26 03:46:49 2011 GMT
+            Not After : Oct 23 03:46:49 2021 GMT
+        Subject: CN=Test Deprecated Digest Intermediate CA
+        Subject Public Key Info:
+            Public Key Algorithm: rsaEncryption
+            RSA Public Key: (1024 bit)
+                Modulus (1024 bit):
+                    00:ac:9b:c0:4b:fc:59:45:7a:d6:3f:a3:89:23:30:
+                    5b:70:ad:ab:78:62:4b:53:85:9f:f9:7d:7f:c1:26:
+                    08:23:80:61:0c:ba:6d:36:06:14:df:29:d4:9c:63:
+                    94:04:ee:14:b6:b9:81:06:2f:33:d8:35:9a:1a:89:
+                    17:ad:21:61:fa:24:75:b9:0c:ef:c1:15:6a:02:bd:
+                    b2:a5:29:df:d8:5f:80:7c:4e:c9:c1:b4:bb:fd:78:
+                    44:63:34:b5:a5:51:aa:e9:23:77:44:53:f9:fa:58:
+                    f6:46:6e:9d:d2:cd:00:a3:28:fe:51:e4:30:7e:49:
+                    62:d4:53:b0:d8:9c:34:47:07
+                Exponent: 65537 (0x10001)
+        X509v3 extensions:
+            X509v3 Basic Constraints: critical
+                CA:TRUE
+            X509v3 Subject Key Identifier: 
+                A8:1D:06:8D:AD:3F:25:51:00:F0:3B:E9:35:C6:65:74:12:51:20:19
+            X509v3 Authority Key Identifier: 
+                keyid:79:82:C5:B4:EB:60:12:4B:B5:87:79:1B:E2:3A:9C:17:76:81:CB:43
+
+            X509v3 Key Usage: critical
+                Certificate Sign, CRL Sign
+    Signature Algorithm: md2WithRSAEncryption
+        95:17:b3:5f:81:5b:9e:d6:e9:de:67:0e:a7:01:2f:b7:f8:db:
+        13:25:6b:a3:15:2d:53:08:c6:20:65:9d:8f:e9:9e:e4:bc:87:
+        78:59:f6:1f:f4:0e:85:c7:a8:c6:c8:6d:65:7e:b9:f4:73:9b:
+        9f:70:2b:b2:0d:03:06:c5:52:5f:59:87:b5:2b:d0:5c:0d:ee:
+        8f:40:cd:eb:95:f2:0e:f4:51:a8:e8:76:17:82:71:1a:d1:ea:
+        99:54:e4:b7:75:27:54:76:36:6f:c0:4d:5d:fa:bb:98:08:1e:
+        d4:95:d1:9a:c7:35:83:d5:a1:79:2a:1f:78:b4:2b:de:17:93:
+        0c:1b
+-----BEGIN CERTIFICATE-----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+-----END CERTIFICATE-----