Log Message:
Update security/mbedtls to 2.2.1.

This breaks removes the legacy PolarSSL compatibility layer. For
software that needs it, please use security/mbedtls1 instead.
Change license to apache-2.0.

Upstream changelog since 1.3.11 follows.

= mbed TLS 2.2.1 released 2016-01-05

Security
- Fix potential double free when mbedtls_asn1_store_named_data() fails
  to allocate memory. Only used for certificate generation, not
  triggerable remotely in SSL/TLS.
- Disable MD5 handshake signatures in TLS 1.2 by default

Bugfix
- Fix over-restrictive length limit in GCM.
- Fix bug in certificate validation that caused valid chains to be
  rejected when the first intermediate certificate has
  pathLenConstraint=0.
- Removed potential leak in mbedtls_rsa_rsassa_pkcs1_v15_sign()
- Fix suboptimal handling of unexpected records that caused interop
  issues with some peers over unreliable links. Avoid dropping an
  entire DTLS datagram if a single record in a datagram is unexpected,
  instead only drop the record and look at subsequent records (if any
  are present) in the same datagram.

= mbed TLS 2.2.0 released 2015-11-04

Security
- Fix potential double free if mbedtls_ssl_conf_psk() is called more
  than once and some allocation fails. Cannot be forced remotely.
- Fix potential heap corruption on Windows when
  mbedtls_x509_crt_parse_path() is passed a path longer than 2GB.
  Cannot be triggered remotely.
- Fix potential buffer overflow in some asn1_write_xxx() functions.
  Cannot be triggered remotely unless you create X.509 certificates
  based on untrusted input or write keys of untrusted origin.
- The X509 max_pathlen constraint was not enforced on intermediate
  certificates.

Features
- Experimental support for EC J-PAKE as defined in Thread 1.0.0.
  Disabled by default as the specification might still change.
- Added a key extraction callback to accees the master secret and key
  block. (Potential uses include EAP-TLS and Thread.)

Bugfix
- Self-signed certificates were not excluded from pathlen counting,
  resulting in some valid X.509 being incorrectly rejected.
- Fix build error with configurations where ECDHE-PSK is the only key
  exchange.
- Fix build error with configurations where RSA, RSA-PSK, ECDH-RSA or
  ECHD-ECDSA if the only key exchange. Multiple reports.
- Fixed a bug causing some handshakes to fail due to some non-fatal
  alerts not being properly ignored.
- mbedtls_x509_crt_verify(_with_profile)() now also checks the key
  type and size/curve against the profile. Before that, there was no
  way to set a minimum key size for end-entity certificates with
  RSA keys.
- Fix failures in MPI on Sparc(64) due to use of bad assembly code.
- Fix typo in name of the extKeyUsage OID.
- Fix bug in ASN.1 encoding of booleans that caused generated CA
  certificates to be rejected by some applications, including OS X
  Keychain.

Changes
- Improved performance of mbedtls_ecp_muladd() when one of the scalars
  is or -1.

= mbed TLS 2.1.2 released 2015-10-06

Security
- Added fix for CVE-2015-5291 to prevent heap corruption due to buffer
  overflow of the hostname or session ticket.
- Fix potential double-free if mbedtls_ssl_set_hs_psk() is called more
  than once in the same handhake and mbedtls_ssl_conf_psk() was used.
- Fix stack buffer overflow in pkcs12 decryption (used by
  mbedtls_pk_parse_key(file)() when the password is > 129 bytes.
- Fix potential buffer overflow in mbedtls_mpi_read_string().
- Fix potential random memory allocation in mbedtls_pem_read_buffer()
  on crafted PEM input data.
- Fix possible heap buffer overflow in base64_encoded() when the input
  buffer is 512MB or larger on 32-bit platforms.
- Fix potential double-free if mbedtls_conf_psk() is called repeatedly
  on the same mbedtls_ssl_config object and memory allocation fails.
- Fix potential heap buffer overflow in servers that perform client
  authentication against a crafted CA cert. Cannot be triggered
  remotely unless you allow third parties to pick trust CAs for
  client auth.

Bugfix
- Fix compile error in net.c with musl libc.
- Fix macroization of 'inline' keyword when building as C++.

Changes
- Added checking of hostname length in mbedtls_ssl_set_hostname() to
  ensure domain names are compliant with RFC 1035.
- Fixed paths for check_config.h in example config files.

= mbed TLS 2.1.1 released 2015-09-17

Security
- Add countermeasure against Lenstra's RSA-CRT attack for PKCS#1 v1.5
  signatures.
- Fix possible client-side NULL pointer dereference (read) when the
  client tries to continue the handshake after it failed (a misuse
  of the API).

Bugfix
- Fix warning when using a 64bit platform.
- Fix off-by-one error in parsing Supported Point Format extension
  that caused some handshakes to fail.

Changes
- Made X509 profile pointer const in mbedtls_ssl_conf_cert_profile()
  to allow use of mbedtls_x509_crt_profile_next.
- When a client initiates a reconnect from the same port as a live
  connection, if cookie verification is available
  (MBEDTLS_SSL_DTLS_HELLO_VERIFY defined in config.h, and usable
  cookie callbacks set with mbedtls_ssl_conf_dtls_cookies()), this
  will be detected and mbedtls_ssl_read() will return
  MBEDTLS_ERR_SSL_CLIENT_RECONNECT - it is then possible to start a
  new handshake with the same context. (See RFC 6347 section 4.2.8.)

= mbed TLS 2.1.0 released 2015-09-04

Features
- Added support for yotta as a build system.
- Primary open source license changed to Apache 2.0 license.

Bugfix
- Fix segfault in the benchmark program when benchmarking DHM.
- Fix build error with CMake and pre-4.5 versions of GCC
- Fix bug when parsing a ServerHello without extensions
- Fix bug in CMake lists that caused libmbedcrypto.a not to be
  installed
- Fix bug in Makefile that caused libmbedcrypto and libmbedx509 not to
  be installed
- Fix compile error with armcc 5 with --gnu option.
- Fix bug in Makefile that caused programs not to be installed
  correctly
- Fix bug in Makefile that prevented from installing without building
  the tests
- Fix missing -static-libgcc when building shared libraries for
  Windows with make.
- Fix link error when building shared libraries for Windows with make.
- Fix error when loading libmbedtls.so.
- Fix bug in mbedtls_ssl_conf_default() that caused the default preset
  to be always used
- Fix bug in mbedtls_rsa_public() and mbedtls_rsa_private() that could
  result trying to unlock an unlocked mutex on invalid input
- Fix -Wshadow warnings
- Fix memory corruption on client with overlong PSK identity, around
  SSL_MAX_CONTENT_LEN or higher - not triggerrable remotely
- Fix unused function warning when using MBEDTLS_MDx_ALT or
  MBEDTLS_SHAxxx_ALT
- Fix memory corruption in pkey programs

Changes
- The PEM parser now accepts a trailing space at end of lines
- It is now possible to #include a user-provided configuration file at
  the end of the default config.h by defining MBEDTLS_USER_CONFIG_FILE on
  the compiler's command line.
- When verifying a certificate chain, if an intermediate certificate
  is trusted, no later cert is checked.
- Prepend a "thread identifier" to debug messages
- Add mbedtls_ssl_get_max_frag_len() to query the current maximum
  fragment length.

= mbed TLS 2.0.0 released 2015-07-13

Features
- Support for DTLS 1.0 and 1.2 (RFC 6347).
- Ability to override core functions from MDx, SHAx, AES and DES
  modules with custom implementation (eg hardware accelerated),
  complementing the ability to override the whole module.
- New server-side implementation of session tickets that rotate keys
  to preserve forward secrecy, and allows sharing across multiple
  contexts.
- Added a concept of X.509 cerificate verification profile that
  controls which algorithms and key sizes (curves for ECDSA) are
  acceptable.
- Expanded configurability of security parameters in the SSL module
  with mbedtls_ssl_conf_dhm_min_bitlen() and mbedtls_ssl_conf_sig_hashes().
- Introduced a concept of presets for SSL security-relevant
  configuration parameters.

API Changes
- The library has been split into libmbedcrypto, libmbedx509,
  libmbedtls. You now need to link to all of them if you use TLS
  for example.
- All public identifiers moved to the mbedtls_* or MBEDTLS_*
  namespace. Some names have been further changed to make them more
  consistent. Migration helpers scripts/rename.pl and
  include/mbedlts/compat-1.3.h are provided. Full list of renamings
  in scripts/data_files/rename-1.3-2.0.txt
- Renamings of fields inside structures, not covered by the previous
  list:
    mbedtls_cipher_info_t.key_length -> key_bitlen
    mbedtls_cipher_context_t.key_length -> key_bitlen
    mbedtls_ecp_curve_info.size -> bit_size
- Headers are now found in the 'mbedtls' directory (previously
  'polarssl').
- The following _init() functions that could return errors have
  been split into an _init() that returns void and another function
  that should generally be the first function called on this context after
  init:
    mbedtls_ssl_init() -> mbedtls_ssl_setup()
    mbedtls_ccm_init() -> mbedtls_ccm_setkey()
    mbedtls_gcm_init() -> mbedtls_gcm_setkey()
    mbedtls_hmac_drbg_init() -> mbedtls_hmac_drbg_seed(_buf)()
    mbedtls_ctr_drbg_init()  -> mbedtls_ctr_drbg_seed()
  Note that for mbedtls_ssl_setup(), you need to be done setting up
  the ssl_config structure before calling it.
- Most ssl_set_xxx() functions (all except ssl_set_bio(),
  ssl_set_hostname(),
  ssl_set_session() and ssl_set_client_transport_id(), plus
  ssl_legacy_renegotiation()) have been renamed to
  mbedtls_ssl_conf_xxx() (see rename.pl and compat-1.3.h above) and
  their first argument's type changed from ssl_context to ssl_config.
- ssl_set_bio() changed signature (contexts merged, order switched,
  one additional callback for read-with-timeout).
- The following functions have been introduced and must be used in
  callback implementations (SNI, PSK) instead of their *conf
  counterparts:
    mbedtls_ssl_set_hs_own_cert()
    mbedtls_ssl_set_hs_ca_chain()
    mbedtls_ssl_set_hs_psk()
- mbedtls_ssl_conf_ca_chain() lost its last argument (peer_cn), now
  set using mbedtls_ssl_set_hostname().
- mbedtls_ssl_conf_session_cache() changed prototype (only one context
  pointer, parameters reordered).
- On server, mbedtls_ssl_conf_session_tickets_cb() must now be used in
  place of mbedtls_ssl_conf_session_tickets() to enable session
  tickets.
- The SSL debug callback gained two new arguments (file name, line
  number).
- Debug modes were removed.
- mbedtls_ssl_conf_truncated_hmac() now returns void.
- mbedtls_memory_buffer_alloc_init() now returns void.
- X.509 verification flags are now an uint32_t. Affect the signature
  of:
    mbedtls_ssl_get_verify_result()
    mbedtls_x509_ctr_verify_info()
    mbedtls_x509_crt_verify() (flags, f_vrfy -> needs to be updated)
    mbedtls_ssl_conf_verify() (f_vrfy -> needs to be updated)
- The following functions changed prototype to avoid an in-out length
  parameter:
    mbedtls_base64_encode()
    mbedtls_base64_decode()
    mbedtls_mpi_write_string()
    mbedtls_dhm_calc_secret()
- In the NET module, all "int" and "int *" arguments for file
  descriptors changed type to "mbedtls_net_context *".
- net_accept() gained new arguments for the size of the client_ip
  buffer.
- In the threading layer, mbedtls_mutex_init() and
  mbedtls_mutex_free() now return void.
- ecdsa_write_signature() gained an addtional md_alg argument and
  ecdsa_write_signature_det() was deprecated.
- pk_sign() no longer accepts md_alg == POLARSSL_MD_NONE with ECDSA.
- Last argument of x509_crt_check_key_usage() and
  mbedtls_x509write_crt_set_key_usage() changed from int to unsigned.
- test_ca_list (from certs.h) is renamed to test_cas_pem and is only
  available if POLARSSL_PEM_PARSE_C is defined (it never worked
  without).
- Test certificates in certs.c are no longer guaranteed to be
  nul-terminated strings; use the new *_len variables instead of strlen().
- Functions mbedtls_x509_xxx_parse(), mbedtls_pk_parse_key(),
  mbedtls_pk_parse_public_key() and mbedtls_dhm_parse_dhm() now expect
  the length parameter to include the terminating null byte for PEM input.
- Signature of mpi_mul_mpi() changed to make the last argument
  unsigned
- calloc() is now used instead of malloc() everywhere. API of platform
  layer and the memory_buffer_alloc module changed accordingly.
- Change SSL_DISABLE_RENEGOTIATION config.h flag to SSL_RENEGOTIATION
  (support for renegotiation now needs explicit enabling in config.h).
- Split MBEDTLS_HAVE_TIME into MBEDTLS_HAVE_TIME and
  MBEDTLS_HAVE_TIME_DATE in config.h
- net_connect() and net_bind() have a new 'proto' argument to choose
  between TCP and UDP, using the macros NET_PROTO_TCP or
  NET_PROTO_UDP. Their 'port' argument type is changed to a string.
- Some constness fixes

Removals
- Removed mbedtls_ecp_group_read_string(). Only named groups are
  supported.
- Removed mbedtls_ecp_sub() and mbedtls_ecp_add(), use
  mbedtls_ecp_muladd().
- Removed individual mdX_hmac, shaX_hmac, mdX_file and shaX_file
  functions (use generic functions from md.h)
- Removed mbedtls_timing_msleep(). Use mbedtls_net_usleep() or a
  custom waiting function.
- Removed test DHM parameters from the test certs module.
- Removed the PBKDF2 module (use PKCS5).
- Removed POLARSSL_ERROR_STRERROR_BC (use mbedtls_strerror()).
- Removed compat-1.2.h (helper for migrating from 1.2 to 1.3).
- Removed openssl.h (very partial OpenSSL compatibility layer).
- Configuration options POLARSSL_HAVE_LONGLONG was removed (now always
  on).
- Configuration options POLARSSL_HAVE_INT8 and POLARSSL_HAVE_INT16
  have been removed (compiler is required to support 32-bit operations).
- Configuration option POLARSSL_HAVE_IPV6 was removed (always
  enabled).
- Removed test program o_p_test, the script compat.sh does more.
- Removed test program ssl_test, superseded by ssl-opt.sh.
- Removed helper script active-config.pl

New deprecations
- md_init_ctx() is deprecated in favour of md_setup(), that adds a
  third argument (allowing memory savings if HMAC is not used)

Semi-API changes (technically public, morally private)
- Renamed a few headers to include _internal in the name. Those
  headers are not supposed to be included by users.
- Changed md_info_t into an opaque structure (use md_get_xxx()
  accessors).
- Changed pk_info_t into an opaque structure.
- Changed cipher_base_t into an opaque structure.
- Removed sig_oid2 and rename sig_oid1 to sig_oid in x509_crt and
  x509_crl.
- x509_crt.key_usage changed from unsigned char to unsigned int.
- Removed r and s from ecdsa_context
- Removed mode from des_context and des3_context

Default behavior changes
- The default minimum TLS version is now TLS 1.0.
- RC4 is now blacklisted by default in the SSL/TLS layer, and excluded
  from the default ciphersuite list returned by ssl_list_ciphersuites()
- Support for receiving SSLv2 ClientHello is now disabled by default
  at compile time.
- The default authmode for SSL/TLS clients is now REQUIRED.
- Support for RSA_ALT contexts in the PK layer is now optional. Since
  is is enabled in the default configuration, this is only noticeable
  if using a custom config.h
- Default DHM parameters server-side upgraded from 1024 to 2048 bits.
- A minimum RSA key size of 2048 bits is now enforced during
  ceritificate chain verification.
- Negotiation of truncated HMAC is now disabled by default on server
  too.
- The following functions are now case-sensitive:
    mbedtls_cipher_info_from_string()
    mbedtls_ecp_curve_info_from_name()
    mbedtls_md_info_from_string()
    mbedtls_ssl_ciphersuite_from_string()
    mbedtls_version_check_feature()

Requirement changes
- The minimum MSVC version required is now 2010 (better C99 support).
- The NET layer now unconditionnaly relies on getaddrinfo() and
  select().
- Compiler is required to support C99 types such as long long and
  uint32_t.

API changes from the 1.4 preview branch
- ssl_set_bio_timeout() was removed, split into mbedtls_ssl_set_bio()
  with new prototype, and mbedtls_ssl_set_read_timeout().
- The following functions now return void:
    mbedtls_ssl_conf_transport()
    mbedtls_ssl_conf_max_version()
    mbedtls_ssl_conf_min_version()
- DTLS no longer hard-depends on TIMING_C, but uses a callback
  interface instead, see mbedtls_ssl_set_timer_cb(), with the Timing
  module providing an example implementation, see
  mbedtls_timing_delay_context and mbedtls_timing_set/get_delay().
- With UDP sockets, it is no longer necessary to call net_bind() again
  after a successful net_accept().

Changes
- mbedtls_ctr_drbg_random() and mbedtls_hmac_drbg_random() are now
  thread-safe if MBEDTLS_THREADING_C is enabled.
- Reduced ROM fooprint of SHA-256 and added an option to reduce it
  even more (at the expense of performance) MBEDTLS_SHA256_SMALLER.