extmod/modssl_mbedtls: Add SSLContext certificate methods.

This commit adds:

1) Methods to SSLContext class that match CPython signature:

	- `SSLContext.load_cert_chain(certfile, keyfile)`
	- `SSLContext.load_verify_locations(cafile=, cadata=)`
	- `SSLContext.get_ciphers()` --> ["CIPHERSUITE"]
	- `SSLContext.set_ciphers(["CIPHERSUITE"])`

2) `sslsocket.cipher()` to get current ciphersuite and protocol
   version.

3) `ssl.MBEDTLS_VERSION` string constant.

4) Certificate verification errors info instead of
   `MBEDTLS_ERR_X509_CERT_VERIFY_FAILED`.

5) Tests in `net_inet` and `multi_net` to test these new methods.

`SSLContext.load_cert_chain` method allows loading key and cert from disk
passing a filepath in `certfile` or `keyfile` options.

`SSLContext.load_verify_locations`'s `cafile` option enables the same
functionality for ca files.

Signed-off-by: Carlos Gil <carlosgilglez@gmail.com>

24 files changed, 558 insertions, 113 deletions

diff --git a/tests/README.md b/tests/README.md
index c89930d0c0..083269d6e8 100644
--- a/tests/README.md
+++ b/tests/README.md
@@ -174,3 +174,21 @@ internal_bench/bytebuf:
     0.177s (+87.78%) internal_bench/bytebuf-3-bytarray_map.py
 1 tests performed (3 individual testcases)
 ```
+
+## Test key/certificates
+
+SSL/TLS tests in `multi_net` and `net_inet` use a 
+self-signed key/cert pair that is randomly generated and to be used for
+testing/demonstration only. You should always generate your own key/cert.
+
+To generate a new self-signed key/cert pair with openssl do:
+```
+$ openssl req -x509 -newkey rsa:4096 -keyout rsa_key.pem -out rsa_cert.pem -days 365 -nodes
+```
+In this case CN is: micropython.local
+
+Convert them to DER format:
+```
+$ openssl rsa -in rsa_key.pem -out rsa_key.der -outform DER
+$ openssl x509 -in rsa_cert.pem -out rsa_cert.der -outform DER
+```
diff --git a/tests/extmod/ssl_sslcontext_ciphers.py b/tests/extmod/ssl_sslcontext_ciphers.py
new file mode 100644
index 0000000000..d87e96afdf
--- /dev/null
+++ b/tests/extmod/ssl_sslcontext_ciphers.py
@@ -0,0 +1,29 @@
+# Basic test of ssl.SSLContext get_ciphers() and set_ciphers() methods.
+
+try:
+    import ssl
+except ImportError:
+    print("SKIP")
+    raise SystemExit
+
+
+ctx = ssl.SSLContext(ssl.PROTOCOL_TLS_CLIENT)
+
+ciphers = ctx.get_ciphers()
+
+for ci in ciphers:
+    print(ci)
+
+ctx.set_ciphers(ciphers[:1])
+
+# Test error cases.
+
+try:
+    ctx.set_ciphers(ciphers[0])
+except TypeError as e:
+    print(e)
+
+try:
+    ctx.set_ciphers(["BAR"])
+except OSError as e:
+    print(e)
diff --git a/tests/extmod/ssl_sslcontext_ciphers.py.exp b/tests/extmod/ssl_sslcontext_ciphers.py.exp
new file mode 100644
index 0000000000..4d243a7883
--- /dev/null
+++ b/tests/extmod/ssl_sslcontext_ciphers.py.exp
@@ -0,0 +1,6 @@
+TLS-ECDHE-ECDSA-WITH-AES-256-CBC-SHA384
+TLS-ECDHE-ECDSA-WITH-AES-128-CBC-SHA256
+TLS-RSA-WITH-AES-256-CBC-SHA256
+TLS-RSA-WITH-AES-128-CBC-SHA256
+object 'str' isn't a tuple or list
+(-24192, 'MBEDTLS_ERR_SSL_BAD_CONFIG')
diff --git a/tests/multi_net/expired_cert.der b/tests/multi_net/expired_cert.der
new file mode 100644
index 0000000000..8e1db02aee
--- /dev/null
+++ b/tests/multi_net/expired_cert.der
diff --git a/tests/multi_net/rsa_cert.der b/tests/multi_net/rsa_cert.der
new file mode 100644
index 0000000000..24ed957eb2
--- /dev/null
+++ b/tests/multi_net/rsa_cert.der
diff --git a/tests/multi_net/rsa_key.der b/tests/multi_net/rsa_key.der
new file mode 100644
index 0000000000..5a4666402a
--- /dev/null
+++ b/tests/multi_net/rsa_key.der
diff --git a/tests/multi_net/ssl_cert_rsa.py b/tests/multi_net/ssl_cert_rsa.py
index 6454ad83aa..71c9a34797 100644
--- a/tests/multi_net/ssl_cert_rsa.py
+++ b/tests/multi_net/ssl_cert_rsa.py
@@ -2,127 +2,29 @@
 # This test won't run under CPython because CPython doesn't have key/cert
 
 try:
-    import binascii, socket, ssl
+    import binascii, os, socket, ssl
 except ImportError:
     print("SKIP")
     raise SystemExit
 
 PORT = 8000
 
+# These are test certificates. See tests/README.md for details.
+certfile = "multi_net/rsa_cert.der"
+keyfile = "multi_net/rsa_key.der"
 
-# This self-signed key/cert pair is randomly generated and to be used for
-# testing/demonstration only.  You should always generate your own key/cert.
-
-# To generate a new self-signed key/cert pair with openssl do:
-# $ openssl req -x509 -newkey rsa:4096 -keyout rsa_key.pem -out rsa_cert.pem -days 1825 -nodes
-#
-# Convert them to DER format:
-# $ openssl rsa -in rsa_key.pem -out rsa_key.der -outform DER
-# $ openssl x509 -in rsa_cert.pem -out rsa_cert.der -outform DER
-#
-# Then convert to hex format, eg using binascii.hexlify(data).
+try:
+    os.stat(certfile)
+    os.stat(keyfile)
+except OSError:
+    print("SKIP")
+    raise SystemExit
 
-cert = binascii.unhexlify(
-    b"308205b53082039da00302010202090090195a9382cbcbef300d06092a864886f70d01010b050030"
-    b"71310b3009060355040613024155310c300a06035504080c03466f6f310c300a06035504070c0342"
-    b"617231143012060355040a0c0b4d6963726f507974686f6e31143012060355040b0c0b4d6963726f"
-    b"507974686f6e311a301806035504030c116d6963726f707974686f6e2e6c6f63616c301e170d3233"
-    b"303731353136323034395a170d3238303731333136323034395a3071310b30090603550406130241"
-    b"55310c300a06035504080c03466f6f310c300a06035504070c0342617231143012060355040a0c0b"
-    b"4d6963726f507974686f6e31143012060355040b0c0b4d6963726f507974686f6e311a3018060355"
-    b"04030c116d6963726f707974686f6e2e6c6f63616c30820222300d06092a864886f70d0101010500"
-    b"0382020f003082020a0282020100944fdb40b587af0cf7e9696c355d24a70936874e6a3bd2598166"
-    b"ce2495aaf9b4af01b54471f7cbf3626ae0720bf0bfd520507f79ec553c62898bfd2598385f56061b"
-    b"0e8f452625c82d3c83e2a0d070ab9be2db21faf88c58e4a61d62f8ff43960aa1ffdadaad41f7cb2e"
-    b"b337070a39f08ff9fe20c09b19926cbbc4a5154b796ff7e7ce11334e090d360c81072af08758f6cd"
-    b"7bad75bc7b95b6dcc801c85de81d72806ca3ce0782bfcbdffce707f9fb1572a7db0d74445dc32d5f"
-    b"bea12a3ab1d47edf668ebfa60ed8b51e654e76292e3894ee574ea851064956906aa8afe00e67664e"
-    b"110b5a6ff7db51f7944463cdd626ff2ec7886c229f4ca5985168f20f8f210972b5ff9181d4f3beb8"
-    b"914ec5b24a0953253b3d42ab55e98bd70cb25e7a24c603b27ec83e1ce31c90b728b47a5f606ff2a1"
-    b"0ff784a016894c28f7e71f51a78b0a7601bbbc8c1b132b04e567394a327a7aa4674e8e4c0bfaec4b"
-    b"eeccf0ed09d1660933d718a2f34ff91d79d875a73fbac07182a9531ca52bd360e2678f95ff9b4ba2"
-    b"1490d7456548364b2eb335c207d6e1e48ccd7d8cb43868a334c095bd9673be7403f3b69b545ee904"
-    b"a3f513d2b2a2dd46f06820cd394819551dd05d9b34a8a3238a521f6c1c3592f76d5ef29e181c60ee"
-    b"bcaf4c63098794c15d4f82e7425e75ff8f5430247ecc0e7f2983b715506012f187d54a7b6729bc61"
-    b"fa4d10a9f22b0203010001a350304e301d0603551d0e041604147a6d126931b58fa1c3dff3c9215f"
-    b"6202e61fa8da301f0603551d230418301680147a6d126931b58fa1c3dff3c9215f6202e61fa8da30"
-    b"0c0603551d13040530030101ff300d06092a864886f70d01010b0500038202010051b3a4834d2bf1"
-    b"95ac645bca61e95289eff38d80ab2ee732c6ebd1370781b66955a7583c78831f9fb7d8b236a1b5ff"
-    b"c9183b4e17225951e1fb2c39f7218af30ec3fd8e4f697e0d10ecd05eb14208535dc55bc1e25d8a43"
-    b"050670d4de3e4cb8c884e6cbb6b884320d496b354acf5258bcb0ddaefd065ee8fccbddf3a2bfa10d"
-    b"bfeb8ab6b2580b50f0678760599269b612f81ba1310bfcd39427fec49211769c514cdd0305081d8a"
-    b"11ebe705496d4dcc31ac9fab96a2d298ee4423789baffbfa0fa82ee1b5113f9cf597647a36640cad"
-    b"abf535205c322e16153d6ab04b0817f57d8a9a6ca2db2ab10986ae9eab343547e52c78a641868bb5"
-    b"e2981182fcc55d86cdc6aa8478b226318a3be72fb726dd0b90f30df810c4d6c6b5a0ecb3c6cc375b"
-    b"8d3d244a07d8517ad390929be7b75f679beb63d8c1028905af2383144a4ed560e45907d301846acc"
-    b"9dbec86bcdd7fbf8a805b59f359c8bd997f5eb7b8aea6f7a538f9663ec2c12e07d4b37650e92b783"
-    b"74356daee4a501eeb27fef79b472b2fcce4363a9ff4d80f96a3b47dc4c4ef380ef231d193a517071"
-    b"b31078fa9f9a80cfd943f7e99e4ed8548c9ea80fd845ecc2c89726be273fa8b36680d645998fd1e6"
-    b"2367638f4953e9af68531aedb2ee49dffaaed07a4a5b97551712058219ac6f8da71710949f761271"
-    b"5273a348dcce40c556bdab00a4ae3a7b23a5934ac88b7640df"
-)
+with open(certfile, "rb") as cf:
+    cert = cadata = cf.read()
 
-key = binascii.unhexlify(
-    b"308209280201000282020100944fdb40b587af0cf7e9696c355d24a70936874e6a3bd2598166ce24"
-    b"95aaf9b4af01b54471f7cbf3626ae0720bf0bfd520507f79ec553c62898bfd2598385f56061b0e8f"
-    b"452625c82d3c83e2a0d070ab9be2db21faf88c58e4a61d62f8ff43960aa1ffdadaad41f7cb2eb337"
-    b"070a39f08ff9fe20c09b19926cbbc4a5154b796ff7e7ce11334e090d360c81072af08758f6cd7bad"
-    b"75bc7b95b6dcc801c85de81d72806ca3ce0782bfcbdffce707f9fb1572a7db0d74445dc32d5fbea1"
-    b"2a3ab1d47edf668ebfa60ed8b51e654e76292e3894ee574ea851064956906aa8afe00e67664e110b"
-    b"5a6ff7db51f7944463cdd626ff2ec7886c229f4ca5985168f20f8f210972b5ff9181d4f3beb8914e"
-    b"c5b24a0953253b3d42ab55e98bd70cb25e7a24c603b27ec83e1ce31c90b728b47a5f606ff2a10ff7"
-    b"84a016894c28f7e71f51a78b0a7601bbbc8c1b132b04e567394a327a7aa4674e8e4c0bfaec4beecc"
-    b"f0ed09d1660933d718a2f34ff91d79d875a73fbac07182a9531ca52bd360e2678f95ff9b4ba21490"
-    b"d7456548364b2eb335c207d6e1e48ccd7d8cb43868a334c095bd9673be7403f3b69b545ee904a3f5"
-    b"13d2b2a2dd46f06820cd394819551dd05d9b34a8a3238a521f6c1c3592f76d5ef29e181c60eebcaf"
-    b"4c63098794c15d4f82e7425e75ff8f5430247ecc0e7f2983b715506012f187d54a7b6729bc61fa4d"
-    b"10a9f22b0203010001028202000b41080520013cc242299f0b4bfd5663aa6a4dd8206d8ba7a90f11"
-    b"036babfea8bc42e7eb5aae8ff656f87f3188406b7e13a6a815ab5e4867bdc236a25caba26857ac43"
-    b"ed9134b4d73cbf83ce759f7b7d3a25fbb4d76376dae3f6caf210ace60703a58951a51852922803d2"
-    b"2b91c82fdf563d85101d2d67c259a7e1e318fb922a71e85015b40beed9e6c90a1d6e1fb45586dcce"
-    b"ceb9c964a356ade82b6275e5c01e492a753f940852df788eab454aadc7d1dc74ddcf7dc493a3e4c9"
-    b"0557bbfe747e701b4b27b5c518a29dbcd8385525a1bb835e72a489096e15387e2f70b112c6bbd79e"
-    b"a97ae2562f7947cd2367635e25b5656a54aac7f1c892243dc135e5025a44d724884b244e8fe4abb4"
-    b"c67bbd2e652d5fc5942b55c24b7f642f65b9b6d37110a955c63eb4f26435be056effbd777f14db8d"
-    b"3d8073f7583b24656edb19911e1307101443a50717c32dbb80b6212e6f0ee43f629b1e718a958a5c"
-    b"fdcd99762f5bff821ac49b0e77c9d1426f8bb31142df030549330dde5cc92fa20d09744ceac6ae02"
-    b"fb354e9b930173e08488375f7c795b3b934c72b58a3353332d5129d56151b57a793d99868885ebd4"
-    b"aac11ca03e09f5b6bd9dda5322a0ab81e468839ea373ecd2b5ac4ffc99740581b35add07f83ff18e"
-    b"c2111555ead17783294b2330ad874bd966c1d60b44e5f379650910a8a05eb92cb7550191c13251f5"
-    b"0a11afa7510282010100c5a4aa380f6bdd4b4524deb44425aa7ef61039a46ad0d09e2ca2cd7fb757"
-    b"ff325f81eaf3a2e790afb3ffb0d71f3ffa52db1a24d3149839f03d1acfe33ef721fe310895986c5a"
-    b"fe88ceb82318ed540456b8aa7e07dc7b982345c4f040b1544bd2ee1e4cb0315bd8db3794ea93d705"
-    b"f41cc1c06badf72de36d2b4a4399846d6c851260e5044e9495be8225307edb97071bdea08c99ccfe"
-    b"54219f6a785db47864e03cf2851abcb62941d3efeea7cdf136d9e23845cf9ea0323b156c686c6d30"
-    b"1cbb5a8c7f1db23a998bf549874b2c13685b20d200d2d91be92c40480a0cca18c28f654dd644c60d"
-    b"e8e03824c0ff83e7cbfc44b2aa16ad537a09565ed4afbe63b8930282010100c01a5e6108420c3d2e"
-    b"ccd0b559e08680f47b3e7271ee4ea9bf4740cc5c418a53225778eddb716447b02d234909f8291581"
-    b"a45be0591952bacda55e774338962502c1d73f2d5383259aaa69f2603fde216ca9557d8b4e629888"
-    b"c697fec1aaf9f99ebd223c06399cc13cd21bd01e3660acc148ba841e5c89b3f8f04efac07f8072a5"
-    b"bacb4f5cfece528496bb35e906361efdb89a17fe4999f47508d5e48914ac651172ddc994993b4672"
-    b"7ec62810d6c204af4b5fd52ba4f8cb3c8720fbd469b219868e28294e60276bc2483e78d96a0edf29"
-    b"e237fe6f1660705d5cd3590c476e37c5d367b19bfb0a1c29ef296dfd3e9fabf5b37e1fb7357a3032"
-    b"c8a641b467d7090282010100bc6d55bf66ac6e69017dba38e0b38c4dc8a8055c845d9a5702b51ff8"
-    b"4042cbd1298f0201cf70b7d75b634d247aed92e9056c72692f3c46188d190fd35647648824154c11"
-    b"ea54025149cbf1e224f9b1bd4007836a594117f5a0e1b62fe72037bddc38d4e231dc9fedb79ae8dd"
-    b"93e5602b3e6905fff02536aaf0d7b78517e4fece0b8c872ac9040d93781e9e92832604a80462ca49"
-    b"234fe1c3c0695061fdd9be4aaeb08447ce5c590f2250a01629586bf3e421c424c1d576ae2fa99010"
-    b"b7346460165ed61de8bac782d0928e4313bd59037051e6691e85e692c2a22bbaafbe555742bca7a8"
-    b"1fae4933e332df317b7f3551c7e91211d6a33c38c4b85a4b46d769b3028201003884497a00a4f5d6"
-    b"d63af9b830fe06744ff926512345ba2ce49280f4debb858799d5e4450e4798fa2251d54cbabb20d3"
-    b"2bf5fff5cc20d01f173b6cc467a9713ae849c11adc29f2ae90874c6e3b74eed42494d90afb7e0f31"
-    b"d323a23a181e4636f345af99bb371df01805b49b11186c6ec6daafcd08e5aeb99d268e05e5b65d42"
-    b"dd914c194841cacfaa24726594edf7e43c3f204ea8c85c9bf806a66efb097302b514773dc41324c6"
-    b"400f1e1b5180ed49d58cb6600fdc143a2ecf8e9ba84d8451502de890e6771181f981a9a782475aa2"
-    b"bb3ecbbc76503e0530e28b676a5e6585d114b63021b4c4afae82a74cadb1cbe61a7e393ff975a942"
-    b"1edebb531f51618902820100214d9f1efa774b9d4e0a996442c2744560c84b133045b1af9241d60f"
-    b"c2f82043ac169dc9496ebb5f26b5cb8a6636c57d44e06843bf1f082be42fe5933a7ab7a6878dccf3"
-    b"58606a9fd6984ea525fe34f9e86f7bae33e707be0dec8fbef2deed253c822f6b812e7bd8c64bc302"
-    b"5c9a9e58811d30981a329f7b130148b0eb2ac62cec516942f7530963edab832bd0bacf344b183b9d"
-    b"ba9d54535dceff640f94d79599edf8dd0c32029950ede63f2f579b0d3c9a13c04df73fec03c4bcbe"
-    b"ff7ecf69ba082445673a263685475b91390963e2d42705ba89ff107e96bbb7a887daa016f282f1e6"
-    b"bdd7b9bb14579166f8c13be876cdef07e13c6ef08ff49d4207c7c7ff"
-)
+with open(keyfile, "rb") as kf:
+    key = kf.read()
 
 
 # Server
@@ -146,7 +48,9 @@ def instance1():
     multitest.next()
     s = socket.socket()
     s.connect(socket.getaddrinfo(IP, PORT)[0][-1])
-    s = ssl.wrap_socket(s, cert_reqs=ssl.CERT_REQUIRED, cadata=cert)
+    s = ssl.wrap_socket(
+        s, cert_reqs=ssl.CERT_REQUIRED, server_hostname="micropython.local", cadata=cadata
+    )
     s.write(b"client to server")
     print(s.read(16))
     s.close()
diff --git a/tests/multi_net/sslcontext_check_hostname_error.py b/tests/multi_net/sslcontext_check_hostname_error.py
new file mode 100644
index 0000000000..94bd472767
--- /dev/null
+++ b/tests/multi_net/sslcontext_check_hostname_error.py
@@ -0,0 +1,59 @@
+# Test creating an SSL connection when server_hostname is required but not specified.
+
+try:
+    import os
+    import socket
+    import ssl
+except ImportError:
+    print("SKIP")
+    raise SystemExit
+
+PORT = 8000
+
+# These are test certificates. See tests/README.md for details.
+cert = cafile = "multi_net/rsa_cert.der"
+key = "multi_net/rsa_key.der"
+
+try:
+    os.stat(cafile)
+    os.stat(key)
+except OSError:
+    print("SKIP")
+    raise SystemExit
+
+
+# Server
+def instance0():
+    multitest.globals(IP=multitest.get_network_ip())
+    s = socket.socket()
+    s.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
+    s.bind(socket.getaddrinfo("0.0.0.0", PORT)[0][-1])
+    s.listen(1)
+    multitest.next()
+    s2, _ = s.accept()
+    server_ctx = ssl.SSLContext(ssl.PROTOCOL_TLS_SERVER)
+    server_ctx.load_cert_chain(cert, key)
+    multitest.broadcast("ready")
+    try:
+        s2 = server_ctx.wrap_socket(s2, server_side=True)
+    except Exception as e:
+        print(e)
+    s.close()
+
+
+# Client
+def instance1():
+    multitest.next()
+    s = socket.socket()
+    s.connect(socket.getaddrinfo(IP, PORT)[0][-1])
+    client_ctx = ssl.SSLContext(ssl.PROTOCOL_TLS_CLIENT)
+    client_ctx.verify_mode = ssl.CERT_REQUIRED
+    client_ctx.load_verify_locations(cafile=cafile)
+    # The client will reject the SSL connection so wait until the server is ready
+    # so that it can see the rejection (otherwise it sees a closed socket).
+    multitest.wait("ready")
+    try:
+        s = client_ctx.wrap_socket(s)
+    except Exception as e:
+        print(e)
+    s.close()
diff --git a/tests/multi_net/sslcontext_check_hostname_error.py.exp b/tests/multi_net/sslcontext_check_hostname_error.py.exp
new file mode 100644
index 0000000000..d29279f860
--- /dev/null
+++ b/tests/multi_net/sslcontext_check_hostname_error.py.exp
@@ -0,0 +1,4 @@
+--- instance0 ---
+(-29312, 'MBEDTLS_ERR_SSL_CONN_EOF')
+--- instance1 ---
+CERT_REQUIRED requires server_hostname
diff --git a/tests/multi_net/sslcontext_getpeercert.py b/tests/multi_net/sslcontext_getpeercert.py
new file mode 100644
index 0000000000..b95b13f0fc
--- /dev/null
+++ b/tests/multi_net/sslcontext_getpeercert.py
@@ -0,0 +1,55 @@
+# Test creating an SSL connection and getting the peer certificate.
+
+try:
+    import os
+    import socket
+    import ssl
+except ImportError:
+    print("SKIP")
+    raise SystemExit
+
+PORT = 8000
+
+# These are test certificates. See tests/README.md for details.
+cert = cafile = "multi_net/rsa_cert.der"
+key = "multi_net/rsa_key.der"
+
+try:
+    os.stat(cafile)
+    os.stat(key)
+except OSError:
+    print("SKIP")
+    raise SystemExit
+
+
+# Server
+def instance0():
+    multitest.globals(IP=multitest.get_network_ip())
+    s = socket.socket()
+    s.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
+    s.bind(socket.getaddrinfo("0.0.0.0", PORT)[0][-1])
+    s.listen(1)
+    multitest.next()
+    s2, _ = s.accept()
+    server_ctx = ssl.SSLContext(ssl.PROTOCOL_TLS_SERVER)
+    server_ctx.load_cert_chain(cert, key)
+    s2 = server_ctx.wrap_socket(s2, server_side=True)
+    print(s2.read(16))
+    s2.write(b"server to client")
+    s2.close()
+    s.close()
+
+
+# Client
+def instance1():
+    multitest.next()
+    s = socket.socket()
+    s.connect(socket.getaddrinfo(IP, PORT)[0][-1])
+    client_ctx = ssl.SSLContext(ssl.PROTOCOL_TLS_CLIENT)
+    client_ctx.verify_mode = ssl.CERT_REQUIRED
+    client_ctx.load_verify_locations(cafile=cafile)
+    s = client_ctx.wrap_socket(s, server_hostname="micropython.local")
+    print(s.getpeercert(True))
+    s.write(b"client to server")
+    print(s.read(16))
+    s.close()
diff --git a/tests/multi_net/sslcontext_getpeercert.py.exp b/tests/multi_net/sslcontext_getpeercert.py.exp
new file mode 100644
index 0000000000..24ab0883e3
--- /dev/null
+++ b/tests/multi_net/sslcontext_getpeercert.py.exp
@@ -0,0 +1,5 @@
+--- instance0 ---
+b'client to server'
+--- instance1 ---
+None
+b'server to client'
diff --git a/tests/multi_net/sslcontext_server_client.py b/tests/multi_net/sslcontext_server_client.py
new file mode 100644
index 0000000000..4d2ac06c58
--- /dev/null
+++ b/tests/multi_net/sslcontext_server_client.py
@@ -0,0 +1,60 @@
+# Test creating an SSL connection with certificates as bytes objects.
+
+try:
+    import os
+    import socket
+    import ssl
+except ImportError:
+    print("SKIP")
+    raise SystemExit
+
+PORT = 8000
+
+# These are test certificates. See tests/README.md for details.
+certfile = "multi_net/rsa_cert.der"
+keyfile = "multi_net/rsa_key.der"
+
+try:
+    os.stat(certfile)
+    os.stat(keyfile)
+except OSError:
+    print("SKIP")
+    raise SystemExit
+
+with open(certfile, "rb") as cf:
+    cert = cadata = cf.read()
+
+with open(keyfile, "rb") as kf:
+    key = kf.read()
+
+
+# Server
+def instance0():
+    multitest.globals(IP=multitest.get_network_ip())
+    s = socket.socket()
+    s.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
+    s.bind(socket.getaddrinfo("0.0.0.0", PORT)[0][-1])
+    s.listen(1)
+    multitest.next()
+    s2, _ = s.accept()
+    server_ctx = ssl.SSLContext(ssl.PROTOCOL_TLS_SERVER)
+    server_ctx.load_cert_chain(cert, key)
+    s2 = server_ctx.wrap_socket(s2, server_side=True)
+    print(s2.read(16))
+    s2.write(b"server to client")
+    s2.close()
+    s.close()
+
+
+# Client
+def instance1():
+    multitest.next()
+    s = socket.socket()
+    s.connect(socket.getaddrinfo(IP, PORT)[0][-1])
+    client_ctx = ssl.SSLContext(ssl.PROTOCOL_TLS_CLIENT)
+    client_ctx.verify_mode = ssl.CERT_REQUIRED
+    client_ctx.load_verify_locations(cadata=cadata)
+    s = client_ctx.wrap_socket(s, server_hostname="micropython.local")
+    s.write(b"client to server")
+    print(s.read(16))
+    s.close()
diff --git a/tests/multi_net/sslcontext_server_client.py.exp b/tests/multi_net/sslcontext_server_client.py.exp
new file mode 100644
index 0000000000..909c496d01
--- /dev/null
+++ b/tests/multi_net/sslcontext_server_client.py.exp
@@ -0,0 +1,4 @@
+--- instance0 ---
+b'client to server'
+--- instance1 ---
+b'server to client'
diff --git a/tests/multi_net/sslcontext_server_client_ciphers.py b/tests/multi_net/sslcontext_server_client_ciphers.py
new file mode 100644
index 0000000000..e2de4e6ad4
--- /dev/null
+++ b/tests/multi_net/sslcontext_server_client_ciphers.py
@@ -0,0 +1,58 @@
+# Test creating an SSL connection with specified ciphers.
+
+try:
+    import os
+    import socket
+    import ssl
+except ImportError:
+    print("SKIP")
+    raise SystemExit
+
+PORT = 8000
+
+# These are test certificates. See tests/README.md for details.
+cert = cafile = "multi_net/rsa_cert.der"
+key = "multi_net/rsa_key.der"
+
+try:
+    os.stat(cafile)
+    os.stat(key)
+except OSError:
+    print("SKIP")
+    raise SystemExit
+
+
+# Server
+def instance0():
+    multitest.globals(IP=multitest.get_network_ip())
+    s = socket.socket()
+    s.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
+    s.bind(socket.getaddrinfo("0.0.0.0", PORT)[0][-1])
+    s.listen(1)
+    multitest.next()
+    s2, _ = s.accept()
+    server_ctx = ssl.SSLContext(ssl.PROTOCOL_TLS_SERVER)
+    server_ctx.load_cert_chain(cert, key)
+    s2 = server_ctx.wrap_socket(s2, server_side=True)
+    assert isinstance(s2.cipher(), tuple)
+    print(s2.read(16))
+    s2.write(b"server to client")
+    s2.close()
+    s.close()
+
+
+# Client
+def instance1():
+    multitest.next()
+    s = socket.socket()
+    s.connect(socket.getaddrinfo(IP, PORT)[0][-1])
+    client_ctx = ssl.SSLContext(ssl.PROTOCOL_TLS_CLIENT)
+    ciphers = client_ctx.get_ciphers()
+    assert "TLS-RSA-WITH-AES-256-CBC-SHA256" in ciphers
+    client_ctx.set_ciphers(["TLS-RSA-WITH-AES-256-CBC-SHA256"])
+    client_ctx.verify_mode = ssl.CERT_REQUIRED
+    client_ctx.load_verify_locations(cafile=cafile)
+    s = client_ctx.wrap_socket(s, server_hostname="micropython.local")
+    s.write(b"client to server")
+    print(s.read(16))
+    s.close()
diff --git a/tests/multi_net/sslcontext_server_client_ciphers.py.exp b/tests/multi_net/sslcontext_server_client_ciphers.py.exp
new file mode 100644
index 0000000000..909c496d01
--- /dev/null
+++ b/tests/multi_net/sslcontext_server_client_ciphers.py.exp
@@ -0,0 +1,4 @@
+--- instance0 ---
+b'client to server'
+--- instance1 ---
+b'server to client'
diff --git a/tests/multi_net/sslcontext_server_client_files.py b/tests/multi_net/sslcontext_server_client_files.py
new file mode 100644
index 0000000000..2c8af21d23
--- /dev/null
+++ b/tests/multi_net/sslcontext_server_client_files.py
@@ -0,0 +1,54 @@
+# Test creating an SSL connection with certificates from a file.
+
+try:
+    import os
+    import socket
+    import ssl
+except ImportError:
+    print("SKIP")
+    raise SystemExit
+
+PORT = 8000
+
+# These are test certificates. See tests/README.md for details.
+cert = cafile = "multi_net/rsa_cert.der"
+key = "multi_net/rsa_key.der"
+
+try:
+    os.stat(cafile)
+    os.stat(key)
+except OSError:
+    print("SKIP")
+    raise SystemExit
+
+
+# Server
+def instance0():
+    multitest.globals(IP=multitest.get_network_ip())
+    s = socket.socket()
+    s.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
+    s.bind(socket.getaddrinfo("0.0.0.0", PORT)[0][-1])
+    s.listen(1)
+    multitest.next()
+    s2, _ = s.accept()
+    server_ctx = ssl.SSLContext(ssl.PROTOCOL_TLS_SERVER)
+    server_ctx.load_cert_chain(cert, key)
+    s2 = server_ctx.wrap_socket(s2, server_side=True)
+    print(s2.read(16))
+    s2.write(b"server to client")
+    s2.close()
+    s.close()
+
+
+# Client
+def instance1():
+    multitest.next()
+    s = socket.socket()
+    s.connect(socket.getaddrinfo(IP, PORT)[0][-1])
+    client_ctx = ssl.SSLContext(ssl.PROTOCOL_TLS_CLIENT)
+    client_ctx.verify_mode = ssl.CERT_REQUIRED
+    client_ctx.load_verify_locations(cafile=cafile)
+    s = client_ctx.wrap_socket(s, server_hostname="micropython.local")
+    s.write(b"client to server")
+    print(s.read(16))
+    s.close()
diff --git a/tests/multi_net/sslcontext_server_client_files.py.exp b/tests/multi_net/sslcontext_server_client_files.py.exp
new file mode 100644
index 0000000000..909c496d01
--- /dev/null
+++ b/tests/multi_net/sslcontext_server_client_files.py.exp
@@ -0,0 +1,4 @@
+--- instance0 ---
+b'client to server'
+--- instance1 ---
+b'server to client'
diff --git a/tests/multi_net/sslcontext_verify_error.py b/tests/multi_net/sslcontext_verify_error.py
new file mode 100644
index 0000000000..4feb4ce983
--- /dev/null
+++ b/tests/multi_net/sslcontext_verify_error.py
@@ -0,0 +1,58 @@
+# Test creating an SSL connection with an invalid certificate.
+
+try:
+    import os
+    import socket
+    import ssl
+except ImportError:
+    print("SKIP")
+    raise SystemExit
+
+PORT = 8000
+
+# These are test certificates. See tests/README.md for details.
+cert = cafile = "multi_net/rsa_cert.der"
+key = "multi_net/rsa_key.der"
+
+try:
+    os.stat(cafile)
+    os.stat(key)
+except OSError:
+    print("SKIP")
+    raise SystemExit
+
+
+# Server
+def instance0():
+    multitest.globals(IP=multitest.get_network_ip())
+    s = socket.socket()
+    s.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
+    s.bind(socket.getaddrinfo("0.0.0.0", PORT)[0][-1])
+    s.listen(1)
+    multitest.next()
+    s2, _ = s.accept()
+    server_ctx = ssl.SSLContext(ssl.PROTOCOL_TLS_SERVER)
+    server_ctx.load_cert_chain(cert, key)
+    try:
+        s2 = server_ctx.wrap_socket(s2, server_side=True)
+    except Exception as e:
+        print(e)
+    multitest.broadcast("finished")
+    s.close()
+
+
+# Client
+def instance1():
+    multitest.next()
+    s = socket.socket()
+    s.connect(socket.getaddrinfo(IP, PORT)[0][-1])
+    client_ctx = ssl.SSLContext(ssl.PROTOCOL_TLS_CLIENT)
+    client_ctx.verify_mode = ssl.CERT_REQUIRED
+    client_ctx.load_verify_locations(cafile=cafile)
+    try:
+        s = client_ctx.wrap_socket(s, server_hostname="foobar.local")
+    except Exception as e:
+        print(e)
+    # Don't close the socket until the server has seen our SSL rejection.
+    multitest.wait("finished")
+    s.close()
diff --git a/tests/multi_net/sslcontext_verify_error.py.exp b/tests/multi_net/sslcontext_verify_error.py.exp
new file mode 100644
index 0000000000..900c7c2308
--- /dev/null
+++ b/tests/multi_net/sslcontext_verify_error.py.exp
@@ -0,0 +1,6 @@
+--- instance0 ---
+(-30592, 'MBEDTLS_ERR_SSL_FATAL_ALERT_MESSAGE')
+--- instance1 ---
+
+The certificate Common Name (CN) does not match with the expected CN
+
diff --git a/tests/multi_net/sslcontext_verify_time_error.py b/tests/multi_net/sslcontext_verify_time_error.py
new file mode 100644
index 0000000000..36711acfc8
--- /dev/null
+++ b/tests/multi_net/sslcontext_verify_time_error.py
@@ -0,0 +1,58 @@
+# Test creating an SSL connection with an expired certificate.
+
+try:
+    import os
+    import socket
+    import ssl
+except ImportError:
+    print("SKIP")
+    raise SystemExit
+
+PORT = 8000
+
+# These are test certificates. See tests/README.md for details.
+cert = cafile = "multi_net/expired_cert.der"
+key = "multi_net/rsa_key.der"
+
+try:
+    os.stat(cafile)
+    os.stat(key)
+except OSError:
+    print("SKIP")
+    raise SystemExit
+
+
+# Server
+def instance0():
+    multitest.globals(IP=multitest.get_network_ip())
+    s = socket.socket()
+    s.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
+    s.bind(socket.getaddrinfo("0.0.0.0", PORT)[0][-1])
+    s.listen(1)
+    multitest.next()
+    s2, _ = s.accept()
+    server_ctx = ssl.SSLContext(ssl.PROTOCOL_TLS_SERVER)
+    server_ctx.load_cert_chain(cert, key)
+    try:
+        s2 = server_ctx.wrap_socket(s2, server_side=True)
+    except Exception as e:
+        print(e)
+    multitest.broadcast("finished")
+    s.close()
+
+
+# Client
+def instance1():
+    multitest.next()
+    s = socket.socket()
+    s.connect(socket.getaddrinfo(IP, PORT)[0][-1])
+    client_ctx = ssl.SSLContext(ssl.PROTOCOL_TLS_CLIENT)
+    client_ctx.verify_mode = ssl.CERT_REQUIRED
+    client_ctx.load_verify_locations(cafile=cafile)
+    try:
+        s = client_ctx.wrap_socket(s, server_hostname="micropython.local")
+    except Exception as e:
+        print(e)
+    # Don't close the socket until the server has seen our SSL rejection.
+    multitest.wait("finished")
+    s.close()
diff --git a/tests/multi_net/sslcontext_verify_time_error.py.exp b/tests/multi_net/sslcontext_verify_time_error.py.exp
new file mode 100644
index 0000000000..25f754c97e
--- /dev/null
+++ b/tests/multi_net/sslcontext_verify_time_error.py.exp
@@ -0,0 +1,6 @@
+--- instance0 ---
+(-30592, 'MBEDTLS_ERR_SSL_FATAL_ALERT_MESSAGE')
+--- instance1 ---
+
+The certificate validity has expired
+
diff --git a/tests/net_inet/mpycert.der b/tests/net_inet/mpycert.der
new file mode 100644
index 0000000000..2d66ea723e
--- /dev/null
+++ b/tests/net_inet/mpycert.der
diff --git a/tests/net_inet/test_sslcontext_client.py b/tests/net_inet/test_sslcontext_client.py
new file mode 100644
index 0000000000..860b053d5b
--- /dev/null
+++ b/tests/net_inet/test_sslcontext_client.py
@@ -0,0 +1,52 @@
+import os
+import socket
+import ssl
+
+# This certificate was obtained from micropython.org using openssl:
+# $ openssl s_client -showcerts -connect micropython.org:443 </dev/null 2>/dev/null
+# The certificate is from Let's Encrypt:
+# 1 s:/C=US/O=Let's Encrypt/CN=R3
+#   i:/C=US/O=Internet Security Research Group/CN=ISRG Root X1
+# Validity
+#            Not Before: Sep  4 00:00:00 2020 GMT
+#            Not After : Sep 15 16:00:00 2025 GMT
+# Copy PEM content to a file (certmpy.pem) and convert to DER e.g.
+# $ openssl x509 -in certmpy.pem -out certmpy.der -outform DER
+# Then convert to hex format, eg using binascii.hexlify(data).
+
+
+ca_cert_chain = "mpycert.der"
+try:
+    os.stat(ca_cert_chain)
+except OSError:
+    print("SKIP")
+    raise SystemExit
+
+
+def main(use_stream=True):
+    context = ssl.SSLContext(ssl.PROTOCOL_TLS_CLIENT)
+
+    context.verify_mode = ssl.CERT_REQUIRED
+    assert context.verify_mode == ssl.CERT_REQUIRED
+
+    context.load_verify_locations(cafile=ca_cert_chain)
+
+    s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
+    addr = socket.getaddrinfo("micropython.org", 443)[0][-1]
+
+    # CPython can wrap the socket even if not connected yet.
+    # ssl_sock = context.wrap_socket(s, server_hostname='micropython.org')
+    # ssl_sock.connect(addr)
+
+    # MicroPython needs to connect first, CPython can do this too.
+    s.connect(addr)
+    # server_hostname must match CN (Common Name) in the certificate
+    # presented by the server
+    ssl_sock = context.wrap_socket(s, server_hostname="micropython.org")
+    ssl_sock.write(b"GET / HTTP/1.0\r\n\r\n")
+    print(ssl_sock.read(17))
+    assert isinstance(ssl_sock.cipher(), tuple)
+    ssl_sock.close()
+
+
+main()
diff --git a/tests/net_inet/test_sslcontext_client.py.exp b/tests/net_inet/test_sslcontext_client.py.exp
new file mode 100644
index 0000000000..fb69ecf1a6
--- /dev/null
+++ b/tests/net_inet/test_sslcontext_client.py.exp
@@ -0,0 +1 @@
+b'HTTP/1.1 200 OK\r\n'