annotate tests/sslcerts/README @ 45095:8e04607023e5

procutil: ensure that procutil.std{out,err}.write() writes all bytes

Python 3 offers different kind of streams and it’s not guaranteed for all of
them that calling write() writes all bytes.

When Python is started in unbuffered mode, sys.std{out,err}.buffer are
instances of io.FileIO, whose write() can write less bytes for
platform-specific reasons (e.g. Linux has a 0x7ffff000 bytes maximum and could
write less if interrupted by a signal; when writing to Windows consoles, it’s
limited to 32767 bytes to avoid the "not enough space" error). This can lead to
silent loss of data, both when using sys.std{out,err}.buffer (which may in fact
not be a buffered stream) and when using the text streams sys.std{out,err}
(I’ve created a CPython bug report for that:
https://bugs.python.org/issue41221).

Python may fix the problem at some point. For now, we implement our own wrapper
for procutil.std{out,err} that calls the raw stream’s write() method until all
bytes have been written. We don’t use sys.std{out,err} for larger writes, so I
think it’s not worth the effort to patch them.

Generate a private key (priv.pem):

  $ openssl genrsa -out priv.pem 2048

Generate 2 self-signed certificates from this key (pub.pem, pub-other.pem):

  $ openssl req -new -x509 -key priv.pem -nodes -sha256 -days 9000 \
    -out pub.pem -batch -subj '/CN=localhost/emailAddress=hg@localhost/'
  $ openssl req -new -x509 -key priv.pem -nodes -sha256 -days 9000 \
    -out pub-other.pem -batch -subj '/CN=localhost/emailAddress=hg@localhost/'

Now generate an expired certificate by turning back the system time:

  $ faketime 2016-01-01T00:00:00Z \
    openssl req -new -x509 -key priv.pem -nodes -sha256 -days 1 \
    -out pub-expired.pem -batch -subj '/CN=localhost/emailAddress=hg@localhost/'

Generate a certificate not yet active by advancing the system time:

  $ faketime 2030-01-1T00:00:00Z \
    openssl req -new -x509 -key priv.pem -nodes -sha256 -days 1 \
    -out pub-not-yet.pem -batch -subj '/CN=localhost/emailAddress=hg@localhost/'

Generate a passphrase protected client certificate private key:

  $ openssl genrsa -aes256 -passout pass:1234 -out client-key.pem 2048

Create a copy of the private key without a passphrase:

  $ openssl rsa -in client-key.pem -passin pass:1234 -out client-key-decrypted.pem

Create a CSR and sign the key using the server keypair:

  $ printf '.\n.\n.\n.\n.\n.\nhg-client@localhost\n.\n.\n' | \
    openssl req -new -key client-key.pem -passin pass:1234 -out client-csr.pem
  $ openssl x509 -req -days 9000 -in client-csr.pem -CA pub.pem -CAkey priv.pem \
    -set_serial 01 -out client-cert.pem

When replacing the certificates, references to certificate fingerprints will
need to be updated in test files.

Fingerprints for certs can be obtained by running:

  $ openssl x509 -in pub.pem -noout -sha1 -fingerprint
  $ openssl x509 -in pub.pem -noout -sha256 -fingerprint