Infineon: Add cyw20829 platform, shared slot feature, json memory map, psoc6 xip

Based in 1.8.0 release of MCUBoot library

This commit adds CYW20829 Infineon platform support with following capabilities:
1. Overwrite and swap upgrade mode support
2. Multi-image with up to 4 images
3. Hardware security counter is supported for CYW20829 platform

Add XIP support for PSOC6 platform - place BOOT slot in external memory and execute it in place using SMIF in XIP mode

and some new features for Infineon devices.

1. Shared upgrade slot feature - use one shared area for upgrade slots of multiple images
2. Memory map defined using JSON file - define memory regions for bootloader and user app in conventional way using JSON file
diff --git a/ext/mbedtls-asn1/include/mbedtls/pk.h b/ext/mbedtls-asn1/include/mbedtls/pk.h
index df3a03c..f3553cc 100644
--- a/ext/mbedtls-asn1/include/mbedtls/pk.h
+++ b/ext/mbedtls-asn1/include/mbedtls/pk.h
@@ -4,7 +4,7 @@
  * \brief Public Key abstraction layer
  */
 /*
- *  Copyright (C) 2006-2015, ARM Limited, All Rights Reserved
+ *  Copyright The Mbed TLS Contributors
  *  SPDX-License-Identifier: Apache-2.0
  *
  *  Licensed under the Apache License, Version 2.0 (the "License"); you may
@@ -18,31 +18,30 @@
  *  WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  *  See the License for the specific language governing permissions and
  *  limitations under the License.
- *
- *  This file is part of mbed TLS (https://tls.mbed.org)
  */
 
 #ifndef MBEDTLS_PK_H
 #define MBEDTLS_PK_H
+#include "mbedtls/private_access.h"
 
-#if !defined(MBEDTLS_CONFIG_FILE)
-#include "config.h"
-#else
-#include MBEDTLS_CONFIG_FILE
-#endif
+#include "mbedtls/build_info.h"
 
-#include "md.h"
+#include "mbedtls/md.h"
 
 #if defined(MBEDTLS_RSA_C)
-#include "rsa.h"
+#include "mbedtls/rsa.h"
 #endif
 
 #if defined(MBEDTLS_ECP_C)
-#include "ecp.h"
+#include "mbedtls/ecp.h"
 #endif
 
 #if defined(MBEDTLS_ECDSA_C)
-#include "ecdsa.h"
+#include "mbedtls/ecdsa.h"
+#endif
+
+#if defined(MBEDTLS_USE_PSA_CRYPTO)
+#include "psa/crypto.h"
 #endif
 
 #if ( defined(__ARMCC_VERSION) || defined(_MSC_VER) ) && \
@@ -64,9 +63,7 @@
 #define MBEDTLS_ERR_PK_UNKNOWN_NAMED_CURVE -0x3A00  /**< Elliptic curve is unsupported (only NIST curves are supported). */
 #define MBEDTLS_ERR_PK_FEATURE_UNAVAILABLE -0x3980  /**< Unavailable feature, e.g. RSA disabled for RSA key. */
 #define MBEDTLS_ERR_PK_SIG_LEN_MISMATCH    -0x3900  /**< The buffer contains a valid signature followed by more data. */
-
-/* MBEDTLS_ERR_PK_HW_ACCEL_FAILED is deprecated and should not be used. */
-#define MBEDTLS_ERR_PK_HW_ACCEL_FAILED     -0x3880  /**< PK hardware accelerator failed. */
+#define MBEDTLS_ERR_PK_BUFFER_TOO_SMALL    -0x3880  /**< The output buffer is too small. */
 
 #ifdef __cplusplus
 extern "C" {
@@ -83,6 +80,7 @@
     MBEDTLS_PK_ECDSA,
     MBEDTLS_PK_RSA_ALT,
     MBEDTLS_PK_RSASSA_PSS,
+    MBEDTLS_PK_OPAQUE,
 } mbedtls_pk_type_t;
 
 /**
@@ -91,12 +89,64 @@
  */
 typedef struct mbedtls_pk_rsassa_pss_options
 {
-    mbedtls_md_type_t mgf1_hash_id;
-    int expected_salt_len;
+    mbedtls_md_type_t MBEDTLS_PRIVATE(mgf1_hash_id);
+    int MBEDTLS_PRIVATE(expected_salt_len);
 
 } mbedtls_pk_rsassa_pss_options;
 
 /**
+ * \brief           Maximum size of a signature made by mbedtls_pk_sign().
+ */
+/* We need to set MBEDTLS_PK_SIGNATURE_MAX_SIZE to the maximum signature
+ * size among the supported signature types. Do it by starting at 0,
+ * then incrementally increasing to be large enough for each supported
+ * signature mechanism.
+ *
+ * The resulting value can be 0, for example if MBEDTLS_ECDH_C is enabled
+ * (which allows the pk module to be included) but neither MBEDTLS_ECDSA_C
+ * nor MBEDTLS_RSA_C nor any opaque signature mechanism (PSA or RSA_ALT).
+ */
+#define MBEDTLS_PK_SIGNATURE_MAX_SIZE 0
+
+#if ( defined(MBEDTLS_RSA_C) || defined(MBEDTLS_PK_RSA_ALT_SUPPORT) ) && \
+    MBEDTLS_MPI_MAX_SIZE > MBEDTLS_PK_SIGNATURE_MAX_SIZE
+/* For RSA, the signature can be as large as the bignum module allows.
+ * For RSA_ALT, the signature size is not necessarily tied to what the
+ * bignum module can do, but in the absence of any specific setting,
+ * we use that (rsa_alt_sign_wrap in library/pk_wrap.h will check). */
+#undef MBEDTLS_PK_SIGNATURE_MAX_SIZE
+#define MBEDTLS_PK_SIGNATURE_MAX_SIZE MBEDTLS_MPI_MAX_SIZE
+#endif
+
+#if defined(MBEDTLS_ECDSA_C) &&                                 \
+    MBEDTLS_ECDSA_MAX_LEN > MBEDTLS_PK_SIGNATURE_MAX_SIZE
+/* For ECDSA, the ecdsa module exports a constant for the maximum
+ * signature size. */
+#undef MBEDTLS_PK_SIGNATURE_MAX_SIZE
+#define MBEDTLS_PK_SIGNATURE_MAX_SIZE MBEDTLS_ECDSA_MAX_LEN
+#endif
+
+#if defined(MBEDTLS_USE_PSA_CRYPTO)
+#if PSA_SIGNATURE_MAX_SIZE > MBEDTLS_PK_SIGNATURE_MAX_SIZE
+/* PSA_SIGNATURE_MAX_SIZE is the maximum size of a signature made
+ * through the PSA API in the PSA representation. */
+#undef MBEDTLS_PK_SIGNATURE_MAX_SIZE
+#define MBEDTLS_PK_SIGNATURE_MAX_SIZE PSA_SIGNATURE_MAX_SIZE
+#endif
+
+#if PSA_VENDOR_ECDSA_SIGNATURE_MAX_SIZE + 11 > MBEDTLS_PK_SIGNATURE_MAX_SIZE
+/* The Mbed TLS representation is different for ECDSA signatures:
+ * PSA uses the raw concatenation of r and s,
+ * whereas Mbed TLS uses the ASN.1 representation (SEQUENCE of two INTEGERs).
+ * Add the overhead of ASN.1: up to (1+2) + 2 * (1+2+1) for the
+ * types, lengths (represented by up to 2 bytes), and potential leading
+ * zeros of the INTEGERs and the SEQUENCE. */
+#undef MBEDTLS_PK_SIGNATURE_MAX_SIZE
+#define MBEDTLS_PK_SIGNATURE_MAX_SIZE ( PSA_VENDOR_ECDSA_SIGNATURE_MAX_SIZE + 11 )
+#endif
+#endif /* defined(MBEDTLS_USE_PSA_CRYPTO) */
+
+/**
  * \brief           Types for interfacing with the debug module
  */
 typedef enum
@@ -111,9 +161,9 @@
  */
 typedef struct mbedtls_pk_debug_item
 {
-    mbedtls_pk_debug_type type;
-    const char *name;
-    void *value;
+    mbedtls_pk_debug_type MBEDTLS_PRIVATE(type);
+    const char *MBEDTLS_PRIVATE(name);
+    void *MBEDTLS_PRIVATE(value);
 } mbedtls_pk_debug_item;
 
 /** Maximum number of item send for debugging, plus 1 */
@@ -129,8 +179,8 @@
  */
 typedef struct mbedtls_pk_context
 {
-    const mbedtls_pk_info_t *   pk_info; /**< Public key information         */
-    void *                      pk_ctx;  /**< Underlying public key context  */
+    const mbedtls_pk_info_t *   MBEDTLS_PRIVATE(pk_info); /**< Public key information         */
+    void *                      MBEDTLS_PRIVATE(pk_ctx);  /**< Underlying public key context  */
 } mbedtls_pk_context;
 
 #if defined(MBEDTLS_ECDSA_C) && defined(MBEDTLS_ECP_RESTARTABLE)
@@ -139,8 +189,8 @@
  */
 typedef struct
 {
-    const mbedtls_pk_info_t *   pk_info; /**< Public key information         */
-    void *                      rs_ctx;  /**< Underlying restart context     */
+    const mbedtls_pk_info_t *   MBEDTLS_PRIVATE(pk_info); /**< Public key information         */
+    void *                      MBEDTLS_PRIVATE(rs_ctx);  /**< Underlying restart context     */
 } mbedtls_pk_restart_ctx;
 #else /* MBEDTLS_ECDSA_C && MBEDTLS_ECP_RESTARTABLE */
 /* Now we can declare functions that take a pointer to that */
@@ -156,7 +206,7 @@
  */
 static inline mbedtls_rsa_context *mbedtls_pk_rsa( const mbedtls_pk_context pk )
 {
-    return( (mbedtls_rsa_context *) (pk).pk_ctx );
+    return( (mbedtls_rsa_context *) (pk).MBEDTLS_PRIVATE(pk_ctx) );
 }
 #endif /* MBEDTLS_RSA_C */
 
@@ -169,7 +219,7 @@
  */
 static inline mbedtls_ecp_keypair *mbedtls_pk_ec( const mbedtls_pk_context pk )
 {
-    return( (mbedtls_ecp_keypair *) (pk).pk_ctx );
+    return( (mbedtls_ecp_keypair *) (pk).MBEDTLS_PRIVATE(pk_ctx) );
 }
 #endif /* MBEDTLS_ECP_C */
 
@@ -177,12 +227,12 @@
 /**
  * \brief           Types for RSA-alt abstraction
  */
-typedef int (*mbedtls_pk_rsa_alt_decrypt_func)( void *ctx, int mode, size_t *olen,
+typedef int (*mbedtls_pk_rsa_alt_decrypt_func)( void *ctx, size_t *olen,
                     const unsigned char *input, unsigned char *output,
                     size_t output_max_len );
 typedef int (*mbedtls_pk_rsa_alt_sign_func)( void *ctx,
                     int (*f_rng)(void *, unsigned char *, size_t), void *p_rng,
-                    int mode, mbedtls_md_type_t md_alg, unsigned int hashlen,
+                    mbedtls_md_type_t md_alg, unsigned int hashlen,
                     const unsigned char *hash, unsigned char *sig );
 typedef size_t (*mbedtls_pk_rsa_alt_key_len_func)( void *ctx );
 #endif /* MBEDTLS_PK_RSA_ALT_SUPPORT */
@@ -197,23 +247,40 @@
 const mbedtls_pk_info_t *mbedtls_pk_info_from_type( mbedtls_pk_type_t pk_type );
 
 /**
- * \brief           Initialize a mbedtls_pk_context (as NONE)
+ * \brief           Initialize a #mbedtls_pk_context (as NONE).
+ *
+ * \param ctx       The context to initialize.
+ *                  This must not be \c NULL.
  */
 void mbedtls_pk_init( mbedtls_pk_context *ctx );
 
 /**
- * \brief           Free a mbedtls_pk_context
+ * \brief           Free the components of a #mbedtls_pk_context.
+ *
+ * \param ctx       The context to clear. It must have been initialized.
+ *                  If this is \c NULL, this function does nothing.
+ *
+ * \note            For contexts that have been set up with
+ *                  mbedtls_pk_setup_opaque(), this does not free the underlying
+ *                  PSA key and you still need to call psa_destroy_key()
+ *                  independently if you want to destroy that key.
  */
 void mbedtls_pk_free( mbedtls_pk_context *ctx );
 
 #if defined(MBEDTLS_ECDSA_C) && defined(MBEDTLS_ECP_RESTARTABLE)
 /**
  * \brief           Initialize a restart context
+ *
+ * \param ctx       The context to initialize.
+ *                  This must not be \c NULL.
  */
 void mbedtls_pk_restart_init( mbedtls_pk_restart_ctx *ctx );
 
 /**
  * \brief           Free the components of a restart context
+ *
+ * \param ctx       The context to clear. It must have been initialized.
+ *                  If this is \c NULL, this function does nothing.
  */
 void mbedtls_pk_restart_free( mbedtls_pk_restart_ctx *ctx );
 #endif /* MBEDTLS_ECDSA_C && MBEDTLS_ECP_RESTARTABLE */
@@ -222,7 +289,8 @@
  * \brief           Initialize a PK context with the information given
  *                  and allocates the type-specific PK subcontext.
  *
- * \param ctx       Context to initialize. Must be empty (type NONE).
+ * \param ctx       Context to initialize. It must not have been set
+ *                  up yet (type #MBEDTLS_PK_NONE).
  * \param info      Information to use
  *
  * \return          0 on success,
@@ -234,11 +302,45 @@
  */
 int mbedtls_pk_setup( mbedtls_pk_context *ctx, const mbedtls_pk_info_t *info );
 
+#if defined(MBEDTLS_USE_PSA_CRYPTO)
+/**
+ * \brief           Initialize a PK context to wrap a PSA key.
+ *
+ * \note            This function replaces mbedtls_pk_setup() for contexts
+ *                  that wrap a (possibly opaque) PSA key instead of
+ *                  storing and manipulating the key material directly.
+ *
+ * \param ctx       The context to initialize. It must be empty (type NONE).
+ * \param key       The PSA key to wrap, which must hold an ECC key pair
+ *                  (see notes below).
+ *
+ * \note            The wrapped key must remain valid as long as the
+ *                  wrapping PK context is in use, that is at least between
+ *                  the point this function is called and the point
+ *                  mbedtls_pk_free() is called on this context. The wrapped
+ *                  key might then be independently used or destroyed.
+ *
+ * \note            This function is currently only available for ECC key
+ *                  pairs (that is, ECC keys containing private key material).
+ *                  Support for other key types may be added later.
+ *
+ * \return          \c 0 on success.
+ * \return          #MBEDTLS_ERR_PK_BAD_INPUT_DATA on invalid input
+ *                  (context already used, invalid key identifier).
+ * \return          #MBEDTLS_ERR_PK_FEATURE_UNAVAILABLE if the key is not an
+ *                  ECC key pair.
+ * \return          #MBEDTLS_ERR_PK_ALLOC_FAILED on allocation failure.
+ */
+int mbedtls_pk_setup_opaque( mbedtls_pk_context *ctx,
+                             const psa_key_id_t key );
+#endif /* MBEDTLS_USE_PSA_CRYPTO */
+
 #if defined(MBEDTLS_PK_RSA_ALT_SUPPORT)
 /**
  * \brief           Initialize an RSA-alt context
  *
- * \param ctx       Context to initialize. Must be empty (type NONE).
+ * \param ctx       Context to initialize. It must not have been set
+ *                  up yet (type #MBEDTLS_PK_NONE).
  * \param key       RSA key pointer
  * \param decrypt_func  Decryption function
  * \param sign_func     Signing function
@@ -258,7 +360,7 @@
 /**
  * \brief           Get the size in bits of the underlying key
  *
- * \param ctx       Context to use
+ * \param ctx       The context to query. It must have been initialized.
  *
  * \return          Key size in bits, or 0 on error
  */
@@ -266,7 +368,8 @@
 
 /**
  * \brief           Get the length in bytes of the underlying key
- * \param ctx       Context to use
+ *
+ * \param ctx       The context to query. It must have been initialized.
  *
  * \return          Key length in bytes, or 0 on error
  */
@@ -278,21 +381,32 @@
 /**
  * \brief           Tell if a context can do the operation given by type
  *
- * \param ctx       Context to test
- * \param type      Target type
+ * \param ctx       The context to query. It must have been initialized.
+ * \param type      The desired type.
  *
- * \return          0 if context can't do the operations,
- *                  1 otherwise.
+ * \return          1 if the context can do operations on the given type.
+ * \return          0 if the context cannot do the operations on the given
+ *                  type. This is always the case for a context that has
+ *                  been initialized but not set up, or that has been
+ *                  cleared with mbedtls_pk_free().
  */
 int mbedtls_pk_can_do( const mbedtls_pk_context *ctx, mbedtls_pk_type_t type );
 
 /**
  * \brief           Verify signature (including padding if relevant).
  *
- * \param ctx       PK context to use
- * \param md_alg    Hash algorithm used (see notes)
+ * \param ctx       The PK context to use. It must have been set up.
+ * \param md_alg    Hash algorithm used.
+ *                  This can be #MBEDTLS_MD_NONE if the signature algorithm
+ *                  does not rely on a hash algorithm (non-deterministic
+ *                  ECDSA, RSA PKCS#1 v1.5).
+ *                  For PKCS#1 v1.5, if \p md_alg is #MBEDTLS_MD_NONE, then
+ *                  \p hash is the DigestInfo structure used by RFC 8017
+ *                  &sect;9.2 steps 3&ndash;6. If \p md_alg is a valid hash
+ *                  algorithm then \p hash is the digest itself, and this
+ *                  function calculates the DigestInfo encoding internally.
  * \param hash      Hash of the message to sign
- * \param hash_len  Hash length or 0 (see notes)
+ * \param hash_len  Hash length
  * \param sig       Signature to verify
  * \param sig_len   Signature length
  *
@@ -304,11 +418,6 @@
  * \note            For RSA keys, the default padding type is PKCS#1 v1.5.
  *                  Use \c mbedtls_pk_verify_ext( MBEDTLS_PK_RSASSA_PSS, ... )
  *                  to verify RSASSA_PSS signatures.
- *
- * \note            If hash_len is 0, then the length associated with md_alg
- *                  is used instead, or an error returned if it is invalid.
- *
- * \note            md_alg may be MBEDTLS_MD_NONE, only if hash_len != 0
  */
 int mbedtls_pk_verify( mbedtls_pk_context *ctx, mbedtls_md_type_t md_alg,
                const unsigned char *hash, size_t hash_len,
@@ -322,7 +431,7 @@
  *                  \c mbedtls_ecp_set_max_ops() to reduce blocking for ECC
  *                  operations. For RSA, same as \c mbedtls_pk_verify().
  *
- * \param ctx       PK context to use
+ * \param ctx       The PK context to use. It must have been set up.
  * \param md_alg    Hash algorithm used (see notes)
  * \param hash      Hash of the message to sign
  * \param hash_len  Hash length or 0 (see notes)
@@ -346,7 +455,7 @@
  *
  * \param type      Signature type (inc. possible padding type) to verify
  * \param options   Pointer to type-specific options, or NULL
- * \param ctx       PK context to use
+ * \param ctx       The PK context to use. It must have been set up.
  * \param md_alg    Hash algorithm used (see notes)
  * \param hash      Hash of the message to sign
  * \param hash_len  Hash length or 0 (see notes)
@@ -377,13 +486,20 @@
 /**
  * \brief           Make signature, including padding if relevant.
  *
- * \param ctx       PK context to use - must hold a private key
+ * \param ctx       The PK context to use. It must have been set up
+ *                  with a private key.
  * \param md_alg    Hash algorithm used (see notes)
  * \param hash      Hash of the message to sign
- * \param hash_len  Hash length or 0 (see notes)
- * \param sig       Place to write the signature
- * \param sig_len   Number of bytes written
- * \param f_rng     RNG function
+ * \param hash_len  Hash length
+ * \param sig       Place to write the signature.
+ *                  It must have enough room for the signature.
+ *                  #MBEDTLS_PK_SIGNATURE_MAX_SIZE is always enough.
+ *                  You may use a smaller buffer if it is large enough
+ *                  given the key type.
+ * \param sig_size  The size of the \p sig buffer in bytes.
+ * \param sig_len   On successful return,
+ *                  the number of bytes written to \p sig.
+ * \param f_rng     RNG function, must not be \c NULL.
  * \param p_rng     RNG parameter
  *
  * \return          0 on success, or a specific error code.
@@ -392,15 +508,12 @@
  *                  There is no interface in the PK module to make RSASSA-PSS
  *                  signatures yet.
  *
- * \note            If hash_len is 0, then the length associated with md_alg
- *                  is used instead, or an error returned if it is invalid.
- *
  * \note            For RSA, md_alg may be MBEDTLS_MD_NONE if hash_len != 0.
  *                  For ECDSA, md_alg may never be MBEDTLS_MD_NONE.
  */
 int mbedtls_pk_sign( mbedtls_pk_context *ctx, mbedtls_md_type_t md_alg,
              const unsigned char *hash, size_t hash_len,
-             unsigned char *sig, size_t *sig_len,
+             unsigned char *sig, size_t sig_size, size_t *sig_len,
              int (*f_rng)(void *, unsigned char *, size_t), void *p_rng );
 
 /**
@@ -411,37 +524,45 @@
  *                  \c mbedtls_ecp_set_max_ops() to reduce blocking for ECC
  *                  operations. For RSA, same as \c mbedtls_pk_sign().
  *
- * \param ctx       PK context to use - must hold a private key
- * \param md_alg    Hash algorithm used (see notes)
+ * \param ctx       The PK context to use. It must have been set up
+ *                  with a private key.
+ * \param md_alg    Hash algorithm used (see notes for mbedtls_pk_sign())
  * \param hash      Hash of the message to sign
- * \param hash_len  Hash length or 0 (see notes)
- * \param sig       Place to write the signature
- * \param sig_len   Number of bytes written
- * \param f_rng     RNG function
+ * \param hash_len  Hash length
+ * \param sig       Place to write the signature.
+ *                  It must have enough room for the signature.
+ *                  #MBEDTLS_PK_SIGNATURE_MAX_SIZE is always enough.
+ *                  You may use a smaller buffer if it is large enough
+ *                  given the key type.
+ * \param sig_size  The size of the \p sig buffer in bytes.
+ * \param sig_len   On successful return,
+ *                  the number of bytes written to \p sig.
+ * \param f_rng     RNG function, must not be \c NULL.
  * \param p_rng     RNG parameter
  * \param rs_ctx    Restart context (NULL to disable restart)
  *
- * \return          See \c mbedtls_pk_sign(), or
+ * \return          See \c mbedtls_pk_sign().
  * \return          #MBEDTLS_ERR_ECP_IN_PROGRESS if maximum number of
  *                  operations was reached: see \c mbedtls_ecp_set_max_ops().
  */
 int mbedtls_pk_sign_restartable( mbedtls_pk_context *ctx,
              mbedtls_md_type_t md_alg,
              const unsigned char *hash, size_t hash_len,
-             unsigned char *sig, size_t *sig_len,
+             unsigned char *sig, size_t sig_size, size_t *sig_len,
              int (*f_rng)(void *, unsigned char *, size_t), void *p_rng,
              mbedtls_pk_restart_ctx *rs_ctx );
 
 /**
  * \brief           Decrypt message (including padding if relevant).
  *
- * \param ctx       PK context to use - must hold a private key
+ * \param ctx       The PK context to use. It must have been set up
+ *                  with a private key.
  * \param input     Input to decrypt
  * \param ilen      Input size
  * \param output    Decrypted output
  * \param olen      Decrypted message length
  * \param osize     Size of the output buffer
- * \param f_rng     RNG function
+ * \param f_rng     RNG function, must not be \c NULL.
  * \param p_rng     RNG parameter
  *
  * \note            For RSA keys, the default padding type is PKCS#1 v1.5.
@@ -456,15 +577,17 @@
 /**
  * \brief           Encrypt message (including padding if relevant).
  *
- * \param ctx       PK context to use
+ * \param ctx       The PK context to use. It must have been set up.
  * \param input     Message to encrypt
  * \param ilen      Message size
  * \param output    Encrypted output
  * \param olen      Encrypted output length
  * \param osize     Size of the output buffer
- * \param f_rng     RNG function
+ * \param f_rng     RNG function, must not be \c NULL.
  * \param p_rng     RNG parameter
  *
+ * \note            \p f_rng is used for padding generation.
+ *
  * \note            For RSA keys, the default padding type is PKCS#1 v1.5.
  *
  * \return          0 on success, or a specific error code.
@@ -479,15 +602,24 @@
  *
  * \param pub       Context holding a public key.
  * \param prv       Context holding a private (and public) key.
+ * \param f_rng     RNG function, must not be \c NULL.
+ * \param p_rng     RNG parameter
  *
- * \return          0 on success or MBEDTLS_ERR_PK_BAD_INPUT_DATA
+ * \return          \c 0 on success (keys were checked and match each other).
+ * \return          #MBEDTLS_ERR_PK_FEATURE_UNAVAILABLE if the keys could not
+ *                  be checked - in that case they may or may not match.
+ * \return          #MBEDTLS_ERR_PK_BAD_INPUT_DATA if a context is invalid.
+ * \return          Another non-zero value if the keys do not match.
  */
-int mbedtls_pk_check_pair( const mbedtls_pk_context *pub, const mbedtls_pk_context *prv );
+int mbedtls_pk_check_pair( const mbedtls_pk_context *pub,
+                           const mbedtls_pk_context *prv,
+                           int (*f_rng)(void *, unsigned char *, size_t),
+                           void *p_rng );
 
 /**
  * \brief           Export debug information
  *
- * \param ctx       Context to use
+ * \param ctx       The PK context to use. It must have been initialized.
  * \param items     Place to write debug items
  *
  * \return          0 on success or MBEDTLS_ERR_PK_BAD_INPUT_DATA
@@ -497,7 +629,7 @@
 /**
  * \brief           Access the type name
  *
- * \param ctx       Context to use
+ * \param ctx       The PK context to use. It must have been initialized.
  *
  * \return          Type name on success, or "invalid PK"
  */
@@ -506,9 +638,10 @@
 /**
  * \brief           Get the key type
  *
- * \param ctx       Context to use
+ * \param ctx       The PK context to use. It must have been initialized.
  *
- * \return          Type on success, or MBEDTLS_PK_NONE
+ * \return          Type on success.
+ * \return          #MBEDTLS_PK_NONE for a context that has not been set up.
  */
 mbedtls_pk_type_t mbedtls_pk_get_type( const mbedtls_pk_context *ctx );
 
@@ -517,12 +650,24 @@
 /**
  * \brief           Parse a private key in PEM or DER format
  *
- * \param ctx       key to be initialized
- * \param key       input buffer
- * \param keylen    size of the buffer
- *                  (including the terminating null byte for PEM data)
- * \param pwd       password for decryption (optional)
- * \param pwdlen    size of the password
+ * \param ctx       The PK context to fill. It must have been initialized
+ *                  but not set up.
+ * \param key       Input buffer to parse.
+ *                  The buffer must contain the input exactly, with no
+ *                  extra trailing material. For PEM, the buffer must
+ *                  contain a null-terminated string.
+ * \param keylen    Size of \b key in bytes.
+ *                  For PEM data, this includes the terminating null byte,
+ *                  so \p keylen must be equal to `strlen(key) + 1`.
+ * \param pwd       Optional password for decryption.
+ *                  Pass \c NULL if expecting a non-encrypted key.
+ *                  Pass a string of \p pwdlen bytes if expecting an encrypted
+ *                  key; a non-encrypted key will also be accepted.
+ *                  The empty password is not supported.
+ * \param pwdlen    Size of the password in bytes.
+ *                  Ignored if \p pwd is \c NULL.
+ * \param f_rng     RNG function, must not be \c NULL. Used for blinding.
+ * \param p_rng     RNG parameter
  *
  * \note            On entry, ctx must be empty, either freshly initialised
  *                  with mbedtls_pk_init() or reset with mbedtls_pk_free(). If you need a
@@ -533,17 +678,23 @@
  * \return          0 if successful, or a specific PK or PEM error code
  */
 int mbedtls_pk_parse_key( mbedtls_pk_context *ctx,
-                  const unsigned char *key, size_t keylen,
-                  const unsigned char *pwd, size_t pwdlen );
+              const unsigned char *key, size_t keylen,
+              const unsigned char *pwd, size_t pwdlen,
+              int (*f_rng)(void *, unsigned char *, size_t), void *p_rng );
 
 /** \ingroup pk_module */
 /**
  * \brief           Parse a public key in PEM or DER format
  *
- * \param ctx       key to be initialized
- * \param key       input buffer
- * \param keylen    size of the buffer
- *                  (including the terminating null byte for PEM data)
+ * \param ctx       The PK context to fill. It must have been initialized
+ *                  but not set up.
+ * \param key       Input buffer to parse.
+ *                  The buffer must contain the input exactly, with no
+ *                  extra trailing material. For PEM, the buffer must
+ *                  contain a null-terminated string.
+ * \param keylen    Size of \b key in bytes.
+ *                  For PEM data, this includes the terminating null byte,
+ *                  so \p keylen must be equal to `strlen(key) + 1`.
  *
  * \note            On entry, ctx must be empty, either freshly initialised
  *                  with mbedtls_pk_init() or reset with mbedtls_pk_free(). If you need a
@@ -561,9 +712,16 @@
 /**
  * \brief           Load and parse a private key
  *
- * \param ctx       key to be initialized
+ * \param ctx       The PK context to fill. It must have been initialized
+ *                  but not set up.
  * \param path      filename to read the private key from
- * \param password  password to decrypt the file (can be NULL)
+ * \param password  Optional password to decrypt the file.
+ *                  Pass \c NULL if expecting a non-encrypted key.
+ *                  Pass a null-terminated string if expecting an encrypted
+ *                  key; a non-encrypted key will also be accepted.
+ *                  The empty password is not supported.
+ * \param f_rng     RNG function, must not be \c NULL. Used for blinding.
+ * \param p_rng     RNG parameter
  *
  * \note            On entry, ctx must be empty, either freshly initialised
  *                  with mbedtls_pk_init() or reset with mbedtls_pk_free(). If you need a
@@ -574,13 +732,15 @@
  * \return          0 if successful, or a specific PK or PEM error code
  */
 int mbedtls_pk_parse_keyfile( mbedtls_pk_context *ctx,
-                      const char *path, const char *password );
+                  const char *path, const char *password,
+                  int (*f_rng)(void *, unsigned char *, size_t), void *p_rng );
 
 /** \ingroup pk_module */
 /**
  * \brief           Load and parse a public key
  *
- * \param ctx       key to be initialized
+ * \param ctx       The PK context to fill. It must have been initialized
+ *                  but not set up.
  * \param path      filename to read the public key from
  *
  * \note            On entry, ctx must be empty, either freshly initialised
@@ -603,14 +763,14 @@
  *                        return value to determine where you should start
  *                        using the buffer
  *
- * \param ctx       private to write away
+ * \param ctx       PK context which must contain a valid private key.
  * \param buf       buffer to write to
  * \param size      size of the buffer
  *
  * \return          length of data written if successful, or a specific
  *                  error code
  */
-int mbedtls_pk_write_key_der( mbedtls_pk_context *ctx, unsigned char *buf, size_t size );
+int mbedtls_pk_write_key_der( const mbedtls_pk_context *ctx, unsigned char *buf, size_t size );
 
 /**
  * \brief           Write a public key to a SubjectPublicKeyInfo DER structure
@@ -618,37 +778,39 @@
  *                        return value to determine where you should start
  *                        using the buffer
  *
- * \param ctx       public key to write away
+ * \param ctx       PK context which must contain a valid public or private key.
  * \param buf       buffer to write to
  * \param size      size of the buffer
  *
  * \return          length of data written if successful, or a specific
  *                  error code
  */
-int mbedtls_pk_write_pubkey_der( mbedtls_pk_context *ctx, unsigned char *buf, size_t size );
+int mbedtls_pk_write_pubkey_der( const mbedtls_pk_context *ctx, unsigned char *buf, size_t size );
 
 #if defined(MBEDTLS_PEM_WRITE_C)
 /**
  * \brief           Write a public key to a PEM string
  *
- * \param ctx       public key to write away
- * \param buf       buffer to write to
- * \param size      size of the buffer
+ * \param ctx       PK context which must contain a valid public or private key.
+ * \param buf       Buffer to write to. The output includes a
+ *                  terminating null byte.
+ * \param size      Size of the buffer in bytes.
  *
  * \return          0 if successful, or a specific error code
  */
-int mbedtls_pk_write_pubkey_pem( mbedtls_pk_context *ctx, unsigned char *buf, size_t size );
+int mbedtls_pk_write_pubkey_pem( const mbedtls_pk_context *ctx, unsigned char *buf, size_t size );
 
 /**
  * \brief           Write a private key to a PKCS#1 or SEC1 PEM string
  *
- * \param ctx       private to write away
- * \param buf       buffer to write to
- * \param size      size of the buffer
+ * \param ctx       PK context which must contain a valid private key.
+ * \param buf       Buffer to write to. The output includes a
+ *                  terminating null byte.
+ * \param size      Size of the buffer in bytes.
  *
  * \return          0 if successful, or a specific error code
  */
-int mbedtls_pk_write_key_pem( mbedtls_pk_context *ctx, unsigned char *buf, size_t size );
+int mbedtls_pk_write_key_pem( const mbedtls_pk_context *ctx, unsigned char *buf, size_t size );
 #endif /* MBEDTLS_PEM_WRITE_C */
 #endif /* MBEDTLS_PK_WRITE_C */
 
@@ -663,7 +825,8 @@
  *
  * \param p         the position in the ASN.1 data
  * \param end       end of the buffer
- * \param pk        the key to fill
+ * \param pk        The PK context to fill. It must have been initialized
+ *                  but not set up.
  *
  * \return          0 if successful, or a specific PK error code
  */
@@ -678,7 +841,7 @@
  *
  * \param p         reference to current position pointer
  * \param start     start of the buffer (for bounds-checking)
- * \param key       public key to write away
+ * \param key       PK context which must contain a valid public or private key.
  *
  * \return          the length written or a negative error code
  */
@@ -694,6 +857,32 @@
 int mbedtls_pk_load_file( const char *path, unsigned char **buf, size_t *n );
 #endif
 
+#if defined(MBEDTLS_USE_PSA_CRYPTO)
+/**
+ * \brief           Turn an EC key into an opaque one.
+ *
+ * \warning         This is a temporary utility function for tests. It might
+ *                  change or be removed at any time without notice.
+ *
+ * \note            Only ECDSA keys are supported so far. Signing with the
+ *                  specified hash is the only allowed use of that key.
+ *
+ * \param pk        Input: the EC key to import to a PSA key.
+ *                  Output: a PK context wrapping that PSA key.
+ * \param key       Output: a PSA key identifier.
+ *                  It's the caller's responsibility to call
+ *                  psa_destroy_key() on that key identifier after calling
+ *                  mbedtls_pk_free() on the PK context.
+ * \param hash_alg  The hash algorithm to allow for use with that key.
+ *
+ * \return          \c 0 if successful.
+ * \return          An Mbed TLS error code otherwise.
+ */
+int mbedtls_pk_wrap_as_opaque( mbedtls_pk_context *pk,
+                               psa_key_id_t *key,
+                               psa_algorithm_t hash_alg );
+#endif /* MBEDTLS_USE_PSA_CRYPTO */
+
 #ifdef __cplusplus
 }
 #endif