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

net/data/ssl/certificates/weak_digest_md4_intermediate.pem

Index: net/data/ssl/certificates/weak_digest_md4_intermediate.pem
diff --git a/net/data/ssl/certificates/weak_digest_md4_intermediate.pem b/net/data/ssl/certificates/weak_digest_md4_intermediate.pem
new file mode 100644
index 0000000000000000000000000000000000000000..2ba01dd82cff3ed860e0d5473e18a32b99c6b068
--- /dev/null
+++ b/net/data/ssl/certificates/weak_digest_md4_intermediate.pem
@@ -0,0 +1,57 @@
+Certificate:
+    Data:
+        Version: 3 (0x2)
+        Serial Number: 3 (0x3)
+        Signature Algorithm: md4WithRSAEncryption
+        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: md4WithRSAEncryption
+        7e:ca:14:3d:14:04:f4:a4:1a:cf:b5:c6:c7:c2:d3:e7:68:08:
+        55:1f:fa:93:28:fa:34:aa:97:29:f7:31:6f:30:a4:25:bd:c5:
+        fe:28:3d:a9:92:b0:4f:ca:24:3f:7b:1a:16:2e:0d:08:73:8e:
+        ca:9f:50:da:e9:64:4f:bd:31:c4:72:89:98:8d:55:55:57:96:
+        6a:e0:5e:00:12:07:8b:3a:30:06:9a:47:a5:94:39:74:a0:f7:
+        e1:00:48:2a:90:08:84:80:e3:6b:83:91:c6:74:d8:d9:c2:72:
+        c7:b9:6e:33:7f:38:46:c1:26:14:5c:1b:85:a3:aa:bb:72:a0:
+        84:b2
+-----BEGIN CERTIFICATE-----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+-----END CERTIFICATE-----