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

net/data/ssl/certificates/weak_digest_md5_intermediate.pem

Index: net/data/ssl/certificates/weak_digest_md5_intermediate.pem
diff --git a/net/data/ssl/certificates/weak_digest_md5_intermediate.pem b/net/data/ssl/certificates/weak_digest_md5_intermediate.pem
new file mode 100644
index 0000000000000000000000000000000000000000..6192ffe97a48c3e485ba3efd318670c16f1d8ebd
--- /dev/null
+++ b/net/data/ssl/certificates/weak_digest_md5_intermediate.pem
@@ -0,0 +1,57 @@
+Certificate:
+    Data:
+        Version: 3 (0x2)
+        Serial Number: 2 (0x2)
+        Signature Algorithm: md5WithRSAEncryption
+        Issuer: CN=Test Deprecated Digest Root CA
+        Validity
+            Not Before: Oct 26 03:46:48 2011 GMT
+            Not After : Oct 23 03:46:48 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: md5WithRSAEncryption
+        a3:9d:4e:8b:42:7b:c2:3a:71:5c:7a:a9:ec:9b:da:04:a4:7d:
+        f2:53:ba:b5:97:97:21:ae:94:03:23:7e:75:0e:c7:cc:1f:57:
+        f2:76:ec:aa:bf:4f:2f:d1:2d:d2:3d:10:55:ce:a0:1c:93:b6:
+        8a:b6:65:9b:67:7a:a6:2f:04:62:e9:31:69:f4:26:08:a3:41:
+        d0:11:3a:21:31:b6:32:5e:a0:4c:32:2d:ca:f8:a0:76:be:f2:
+        a1:bf:15:98:73:26:41:2d:d5:8e:63:e7:5e:ef:61:08:f0:9d:
+        fb:af:55:1e:37:9c:2a:13:f7:7e:ab:5c:f4:d5:f8:7c:a7:fb:
+        c0:42
+-----BEGIN CERTIFICATE-----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+-----END CERTIFICATE-----