Merge pull request ARMmbed#3176 from aggarg/development

.pylintrc

@@ -40,7 +40,27 @@ max-attributes=15
 max-module-lines=2000
 
 [MESSAGES CONTROL]
-disable=
+# * locally-disabled, locally-enabled: If we disable or enable a message
+#   locally, it's by design. There's no need to clutter the Pylint output
+#   with this information.
+# * logging-format-interpolation: Pylint warns about things like
+#   ``log.info('...'.format(...))``. It insists on ``log.info('...', ...)``.
+#   This is of minor utility (mainly a performance gain when there are
+#   many messages that use formatting and are below the log level).
+#   Some versions of Pylint (including 1.8, which is the version on
+#   Ubuntu 18.04) only recognize old-style format strings using '%',
+#   and complain about something like ``log.info('{}', foo)`` with
+#   logging-too-many-args (Pylint supports new-style formatting if
+#   declared globally with logging_format_style under [LOGGING] but
+#   this requires Pylint >=2.2).
+# * no-else-return: Allow the perfectly reasonable idiom
+#    if condition1:
+#        return value1
+#    else:
+#        return value2
+# * unnecessary-pass: If we take the trouble of adding a line with "pass",
+#   it's because we think the code is clearer that way.
+disable=locally-disabled,locally-enabled,logging-format-interpolation,no-else-return,unnecessary-pass
 
 [REPORTS]
 # Don't diplay statistics. Just the facts.

ChangeLog

@@ -1,10 +1,14 @@
 mbed TLS ChangeLog (Sorted per branch, date)
 
-= mbed TLS x.x.x branch released xxxx-xx-xx
+= mbed TLS 2.22.0 branch released 2020-04-14
 
 New deprecations
    * Deprecate MBEDTLS_SSL_HW_RECORD_ACCEL that enables function hooks in the
      SSL module for hardware acceleration of individual records.
+   * Deprecate mbedtls_ssl_get_max_frag_len() in favour of
+     mbedtls_ssl_get_output_max_frag_len() and
+     mbedtls_ssl_get_input_max_frag_len() to be more precise about which max
+     fragment length is desired.
 
 Security
    * Fix issue in DTLS handling of new associations with the same parameters
@@ -13,16 +17,35 @@ Security
      legitimate clients, resulting in a Denial of Service. This could only
      happen when MBEDTLS_SSL_DTLS_CLIENT_PORT_REUSE was enabled in config.h
      (which it is by default).
+   * Fix side channel in ECC code that allowed an adversary with access to
+     precise enough timing and memory access information (typically an
+     untrusted operating system attacking a secure enclave) to fully recover
+     an ECDSA private key. Found and reported by Alejandro Cabrera Aldaya,
+     Billy Brumley and Cesar Pereida Garcia. CVE-2020-10932
+   * Fix a potentially remotely exploitable buffer overread in a
+     DTLS client when parsing the Hello Verify Request message.
+
+Features
+   * The new build option MBEDTLS_SSL_VARIABLE_BUFFER_LENGTH automatically
+     resizes the I/O buffers before and after handshakes, reducing the memory
+     consumption during application data transfer.
 
 Bugfix
    * Fix compilation failure when both MBEDTLS_SSL_PROTO_DTLS and
      MBEDTLS_SSL_HW_RECORD_ACCEL are enabled.
    * Remove a spurious check in ssl_parse_client_psk_identity that triggered
      a warning with some compilers. Fix contributed by irwir in #2856.
+   * Fix a function name in a debug message. Contributed by Ercan Ozturk in
+     #3013.
 
 Changes
    * Mbed Crypto is no longer a Git submodule. The crypto part of the library
      is back directly in the present repository.
+   * Split mbedtls_ssl_get_max_frag_len() into
+     mbedtls_ssl_get_output_max_frag_len() and
+     mbedtls_ssl_get_input_max_frag_len() to ensure that a sufficient input
+     buffer is allocated by the server (if MBEDTLS_SSL_VARIABLE_BUFFER_LENGTH
+     is defined), regardless of what MFL was configured for it.
 
 = mbed TLS 2.21.0 branch released 2020-02-20
 

Makefile

@@ -124,8 +124,10 @@ endif
 
 ## Editor navigation files
 C_SOURCE_FILES = $(wildcard include/*/*.h library/*.[hc] programs/*/*.[hc] tests/suites/*.function)
+# Exuberant-ctags invocation. Other ctags implementations may require different options.
+CTAGS = ctags --langmap=c:+.h.function -o
 tags: $(C_SOURCE_FILES)
-	ctags -o $@ $(C_SOURCE_FILES)
+	$(CTAGS) $@ $(C_SOURCE_FILES)
 TAGS: $(C_SOURCE_FILES)
 	etags -o $@ $(C_SOURCE_FILES)
 GPATH GRTAGS GSYMS GTAGS: $(C_SOURCE_FILES)

doxygen/input/doc_mainpage.h

@@ -24,7 +24,7 @@
  */
 
 /**
- * @mainpage mbed TLS v2.21.0 source code documentation
+ * @mainpage mbed TLS v2.22.0 source code documentation
  *
  * This documentation describes the internal structure of mbed TLS.  It was
  * automatically generated from specially formatted comment blocks in

doxygen/mbedtls.doxyfile

@@ -28,7 +28,7 @@ DOXYFILE_ENCODING      = UTF-8
 # identify the project. Note that if you do not use Doxywizard you need
 # to put quotes around the project name if it contains spaces.
 
-PROJECT_NAME           = "mbed TLS v2.21.0"
+PROJECT_NAME           = "mbed TLS v2.22.0"
 
 # The PROJECT_NUMBER tag can be used to enter a project or revision number.
 # This could be handy for archiving the generated documentation or

include/mbedtls/error.h

@@ -127,6 +127,36 @@ extern "C" {
  */
 void mbedtls_strerror( int errnum, char *buffer, size_t buflen );
 
+/**
+ * \brief Translate the high-level part of an Mbed TLS error code into a string
+ *        representation.
+ *
+ * This function returns a const pointer to an un-modifiable string. The caller
+ * must not try to modify the string. It is intended to be used mostly for
+ * logging purposes.
+ *
+ * \param error_code    error code
+ *
+ * \return The string representation of the error code, or \c NULL if the error
+ *         code is unknown.
+ */
+const char * mbedtls_high_level_strerr( int error_code );
+
+/**
+ * \brief Translate the low-level part of an Mbed TLS error code into a string
+ *        representation.
+ *
+ * This function returns a const pointer to an un-modifiable string. The caller
+ * must not try to modify the string. It is intended to be used mostly for
+ * logging purposes.
+ *
+ * \param error_code    error code
+ *
+ * \return The string representation of the error code, or \c NULL if the error
+ *         code is unknown.
+ */
+const char * mbedtls_low_level_strerr( int error_code );
+
 #ifdef __cplusplus
 }
 #endif

include/mbedtls/ssl.h

@@ -2682,6 +2682,9 @@ int mbedtls_ssl_conf_own_cert( mbedtls_ssl_config *conf,
  * \note           This is mainly useful for clients. Servers will usually
  *                 want to use \c mbedtls_ssl_conf_psk_cb() instead.
  *
+ * \note           A PSK set by \c mbedtls_ssl_set_hs_psk() in the PSK callback
+ *                 takes precedence over a PSK configured by this function.
+ *
  * \warning        Currently, clients can only register a single pre-shared key.
  *                 Calling this function or mbedtls_ssl_conf_psk_opaque() more
  *                 than once will overwrite values configured in previous calls.
@@ -2715,6 +2718,10 @@ int mbedtls_ssl_conf_psk( mbedtls_ssl_config *conf,
  * \note           This is mainly useful for clients. Servers will usually
  *                 want to use \c mbedtls_ssl_conf_psk_cb() instead.
  *
+ * \note           An opaque PSK set by \c mbedtls_ssl_set_hs_psk_opaque() in
+ *                 the PSK callback takes precedence over an opaque PSK
+ *                 configured by this function.
+ *
  * \warning        Currently, clients can only register a single pre-shared key.
  *                 Calling this function or mbedtls_ssl_conf_psk() more than
  *                 once will overwrite values configured in previous calls.
@@ -2752,6 +2759,9 @@ int mbedtls_ssl_conf_psk_opaque( mbedtls_ssl_config *conf,
  * \note           This should only be called inside the PSK callback,
  *                 i.e. the function passed to \c mbedtls_ssl_conf_psk_cb().
  *
+ * \note           A PSK set by this function takes precedence over a PSK
+ *                 configured by \c mbedtls_ssl_conf_psk().
+ *
  * \param ssl      The SSL context to configure a PSK for.
  * \param psk      The pointer to the pre-shared key.
  * \param psk_len  The length of the pre-shared key in bytes.
@@ -2769,6 +2779,9 @@ int mbedtls_ssl_set_hs_psk( mbedtls_ssl_context *ssl,
  * \note           This should only be called inside the PSK callback,
  *                 i.e. the function passed to \c mbedtls_ssl_conf_psk_cb().
  *
+ * \note           An opaque PSK set by this function takes precedence over an
+ *                 opaque PSK configured by \c mbedtls_ssl_conf_psk_opaque().
+ *
  * \param ssl      The SSL context to configure a PSK for.
  * \param psk      The identifier of the key slot holding the PSK.
  *                 For the duration of the current handshake, the key slot
@@ -2807,9 +2820,14 @@ int mbedtls_ssl_set_hs_psk_opaque( mbedtls_ssl_context *ssl,
  *                 on the SSL context to set the correct PSK and return \c 0.
  *                 Any other return value will result in a denied PSK identity.
  *
- * \note           If you set a PSK callback using this function, then you
- *                 don't need to set a PSK key and identity using
- *                 \c mbedtls_ssl_conf_psk().
+ * \note           A dynamic PSK (i.e. set by the PSK callback) takes
+ *                 precedence over a static PSK (i.e. set by
+ *                 \c mbedtls_ssl_conf_psk() or
+ *                 \c mbedtls_ssl_conf_psk_opaque()).
+ *                 This means that if you set a PSK callback using this
+ *                 function, you don't need to set a PSK using
+ *                 \c mbedtls_ssl_conf_psk() or
+ *                 \c mbedtls_ssl_conf_psk_opaque()).
  *
  * \param conf     The SSL configuration to register the callback with.
  * \param f_psk    The callback for selecting and setting the PSK based
@@ -3523,18 +3541,61 @@ int mbedtls_ssl_get_record_expansion( const mbedtls_ssl_context *ssl );
 
 #if defined(MBEDTLS_SSL_MAX_FRAGMENT_LENGTH)
 /**
- * \brief          Return the maximum fragment length (payload, in bytes).
- *                 This is the value negotiated with peer if any,
- *                 or the locally configured value.
+ * \brief          Return the maximum fragment length (payload, in bytes) for
+ *                 the output buffer. For the client, this is the configured
+ *                 value. For the server, it is the minimum of two - the
+ *                 configured value and the negotiated one.
  *
  * \sa             mbedtls_ssl_conf_max_frag_len()
  * \sa             mbedtls_ssl_get_max_record_payload()
  *
  * \param ssl      SSL context
  *
- * \return         Current maximum fragment length.
+ * \return         Current maximum fragment length for the output buffer.
  */
-size_t mbedtls_ssl_get_max_frag_len( const mbedtls_ssl_context *ssl );
+size_t mbedtls_ssl_get_output_max_frag_len( const mbedtls_ssl_context *ssl );
+
+/**
+ * \brief          Return the maximum fragment length (payload, in bytes) for
+ *                 the input buffer. This is the negotiated maximum fragment
+ *                 length, or, if there is none, MBEDTLS_SSL_MAX_CONTENT_LEN.
+ *                 If it is not defined either, the value is 2^14. This function
+ *                 works as its predecessor, \c mbedtls_ssl_get_max_frag_len().
+ *
+ * \sa             mbedtls_ssl_conf_max_frag_len()
+ * \sa             mbedtls_ssl_get_max_record_payload()
+ *
+ * \param ssl      SSL context
+ *
+ * \return         Current maximum fragment length for the output buffer.
+ */
+size_t mbedtls_ssl_get_input_max_frag_len( const mbedtls_ssl_context *ssl );
+
+#if !defined(MBEDTLS_DEPRECATED_REMOVED)
+
+#if defined(MBEDTLS_DEPRECATED_WARNING)
+#define MBEDTLS_DEPRECATED    __attribute__((deprecated))
+#else
+#define MBEDTLS_DEPRECATED
+#endif
+
+/**
+ * \brief          This function is a deprecated approach to getting the max
+ *                 fragment length. Its an alias for
+ *                 \c mbedtls_ssl_get_output_max_frag_len(), as the behaviour
+ *                 is the same. See \c mbedtls_ssl_get_output_max_frag_len() for
+ *                 more detail.
+ *
+ * \sa             mbedtls_ssl_get_input_max_frag_len()
+ * \sa             mbedtls_ssl_get_output_max_frag_len()
+ *
+ * \param ssl      SSL context
+ *
+ * \return         Current maximum fragment length for the output buffer.
+ */
+MBEDTLS_DEPRECATED size_t mbedtls_ssl_get_max_frag_len(
+                                        const mbedtls_ssl_context *ssl );
+#endif /* MBEDTLS_DEPRECATED_REMOVED */
 #endif /* MBEDTLS_SSL_MAX_FRAGMENT_LENGTH */
 
 /**
@@ -3555,7 +3616,8 @@ size_t mbedtls_ssl_get_max_frag_len( const mbedtls_ssl_context *ssl );
  *                 when record compression is enabled.
  *
  * \sa             mbedtls_ssl_set_mtu()
- * \sa             mbedtls_ssl_get_max_frag_len()
+ * \sa             mbedtls_ssl_get_output_max_frag_len()
+ * \sa             mbedtls_ssl_get_input_max_frag_len()
  * \sa             mbedtls_ssl_get_record_expansion()
  *
  * \param ssl      SSL context
@@ -3863,8 +3925,8 @@ int mbedtls_ssl_read( mbedtls_ssl_context *ssl, unsigned char *buf, size_t len )
  *                 or negotiated with the peer), then:
  *                 - with TLS, less bytes than requested are written.
  *                 - with DTLS, MBEDTLS_ERR_SSL_BAD_INPUT_DATA is returned.
- *                 \c mbedtls_ssl_get_max_frag_len() may be used to query the
- *                 active maximum fragment length.
+ *                 \c mbedtls_ssl_get_output_max_frag_len() may be used to
+ *                 query the active maximum fragment length.
  *
  * \note           Attempting to write 0 bytes will result in an empty TLS
  *                 application record being sent.

include/mbedtls/ssl_internal.h

@@ -260,23 +260,23 @@
 static inline uint32_t mbedtls_ssl_get_output_buflen( const mbedtls_ssl_context *ctx )
 {
 #if defined (MBEDTLS_SSL_DTLS_CONNECTION_ID)
-    return (uint32_t) mbedtls_ssl_get_max_frag_len( ctx )
+    return (uint32_t) mbedtls_ssl_get_output_max_frag_len( ctx )
                + MBEDTLS_SSL_HEADER_LEN + MBEDTLS_SSL_PAYLOAD_OVERHEAD
                + MBEDTLS_SSL_CID_OUT_LEN_MAX;
 #else
-    return (uint32_t) mbedtls_ssl_get_max_frag_len( ctx )
+    return (uint32_t) mbedtls_ssl_get_output_max_frag_len( ctx )
                + MBEDTLS_SSL_HEADER_LEN + MBEDTLS_SSL_PAYLOAD_OVERHEAD;
 #endif
 }
 
 static inline uint32_t mbedtls_ssl_get_input_buflen( const mbedtls_ssl_context *ctx )
 {
 #if defined (MBEDTLS_SSL_DTLS_CONNECTION_ID)
-    return (uint32_t) mbedtls_ssl_get_max_frag_len( ctx )
+    return (uint32_t) mbedtls_ssl_get_input_max_frag_len( ctx )
                + MBEDTLS_SSL_HEADER_LEN + MBEDTLS_SSL_PAYLOAD_OVERHEAD
                + MBEDTLS_SSL_CID_IN_LEN_MAX;
 #else
-    return (uint32_t) mbedtls_ssl_get_max_frag_len( ctx )
+    return (uint32_t) mbedtls_ssl_get_input_max_frag_len( ctx )
                + MBEDTLS_SSL_HEADER_LEN + MBEDTLS_SSL_PAYLOAD_OVERHEAD;
 #endif
 }
@@ -921,7 +921,60 @@ void mbedtls_ssl_optimize_checksum( mbedtls_ssl_context *ssl,
 
 #if defined(MBEDTLS_KEY_EXCHANGE_SOME_PSK_ENABLED)
 int mbedtls_ssl_psk_derive_premaster( mbedtls_ssl_context *ssl, mbedtls_key_exchange_type_t key_ex );
-#endif
+
+/**
+ * Get the first defined PSK by order of precedence:
+ * 1. handshake PSK set by \c mbedtls_ssl_set_hs_psk() in the PSK callback
+ * 2. static PSK configured by \c mbedtls_ssl_conf_psk()
+ * Return a code and update the pair (PSK, PSK length) passed to this function
+ */
+static inline int mbedtls_ssl_get_psk( const mbedtls_ssl_context *ssl,
+    const unsigned char **psk, size_t *psk_len )
+{
+    if( ssl->handshake->psk != NULL && ssl->handshake->psk_len > 0 )
+    {
+        *psk = ssl->handshake->psk;
+        *psk_len = ssl->handshake->psk_len;
+    }
+
+    else if( ssl->conf->psk != NULL && ssl->conf->psk_len > 0 )
+    {
+        *psk = ssl->conf->psk;
+        *psk_len = ssl->conf->psk_len;
+    }
+
+    else
+    {
+        *psk = NULL;
+        *psk_len = 0;
+        return( MBEDTLS_ERR_SSL_PRIVATE_KEY_REQUIRED );
+    }
+
+    return( 0 );
+}
+
+#if defined(MBEDTLS_USE_PSA_CRYPTO)
+/**
+ * Get the first defined opaque PSK by order of precedence:
+ * 1. handshake PSK set by \c mbedtls_ssl_set_hs_psk_opaque() in the PSK
+ *    callback
+ * 2. static PSK configured by \c mbedtls_ssl_conf_psk_opaque()
+ * Return an opaque PSK
+ */
+static inline psa_key_handle_t mbedtls_ssl_get_opaque_psk(
+    const mbedtls_ssl_context *ssl )
+{
+    if( ssl->handshake->psk_opaque != 0 )
+        return( ssl->handshake->psk_opaque );
+
+    if( ssl->conf->psk_opaque != 0 )
+        return( ssl->conf->psk_opaque );
+
+    return( 0 );
+}
+#endif /* MBEDTLS_USE_PSA_CRYPTO */
+
+#endif /* MBEDTLS_KEY_EXCHANGE_SOME_PSK_ENABLED */
 
 #if defined(MBEDTLS_PK_C)
 unsigned char mbedtls_ssl_sig_from_pk( mbedtls_pk_context *pk );