Diff: features/mbedtls/mbed-crypto/src/pk_wrap.c

Revision:

0:5b88d5760320

Child:

1:9db0e321a9f4

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/features/mbedtls/mbed-crypto/src/pk_wrap.c	Tue Dec 17 23:23:45 2019 +0000
@@ -0,0 +1,1058 @@
+/*
+ *  Public Key abstraction layer: wrapper functions
+ *
+ *  Copyright (C) 2006-2015, ARM Limited, All Rights Reserved
+ *  SPDX-License-Identifier: Apache-2.0
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License"); you may
+ *  not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *  http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+ *  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)
+ */
+
+#if !defined(MBEDTLS_CONFIG_FILE)
+#include "mbedtls/config.h"
+#else
+#include MBEDTLS_CONFIG_FILE
+#endif
+
+#if defined(MBEDTLS_PK_C)
+#include "mbedtls/pk_internal.h"
+
+/* Even if RSA not activated, for the sake of RSA-alt */
+#include "mbedtls/rsa.h"
+
+#include <string.h>
+
+#if defined(MBEDTLS_ECP_C)
+#include "mbedtls/ecp.h"
+#endif
+
+#if defined(MBEDTLS_ECDSA_C)
+#include "mbedtls/ecdsa.h"
+#endif
+
+#if defined(MBEDTLS_USE_PSA_CRYPTO)
+#include "mbedtls/asn1write.h"
+#endif
+
+#if defined(MBEDTLS_PK_RSA_ALT_SUPPORT)
+#include "mbedtls/platform_util.h"
+#endif
+
+#if defined(MBEDTLS_USE_PSA_CRYPTO)
+#include "psa/crypto.h"
+#include "mbedtls/psa_util.h"
+#include "mbedtls/asn1.h"
+#endif
+
+#if defined(MBEDTLS_PLATFORM_C)
+#include "mbedtls/platform.h"
+#else
+#include <stdlib.h>
+#define mbedtls_calloc    calloc
+#define mbedtls_free       free
+#endif
+
+#include <limits.h>
+#include <stdint.h>
+
+#if defined(MBEDTLS_RSA_C)
+static int rsa_can_do( mbedtls_pk_type_t type )
+{
+    return( type == MBEDTLS_PK_RSA ||
+            type == MBEDTLS_PK_RSASSA_PSS );
+}
+
+static size_t rsa_get_bitlen( const void *ctx )
+{
+    const mbedtls_rsa_context * rsa = (const mbedtls_rsa_context *) ctx;
+    return( 8 * mbedtls_rsa_get_len( rsa ) );
+}
+
+static int rsa_verify_wrap( void *ctx, mbedtls_md_type_t md_alg,
+                   const unsigned char *hash, size_t hash_len,
+                   const unsigned char *sig, size_t sig_len )
+{
+    int ret;
+    mbedtls_rsa_context * rsa = (mbedtls_rsa_context *) ctx;
+    size_t rsa_len = mbedtls_rsa_get_len( rsa );
+
+#if SIZE_MAX > UINT_MAX
+    if( md_alg == MBEDTLS_MD_NONE && UINT_MAX < hash_len )
+        return( MBEDTLS_ERR_PK_BAD_INPUT_DATA );
+#endif /* SIZE_MAX > UINT_MAX */
+
+    if( sig_len < rsa_len )
+        return( MBEDTLS_ERR_RSA_VERIFY_FAILED );
+
+    if( ( ret = mbedtls_rsa_pkcs1_verify( rsa, NULL, NULL,
+                                  MBEDTLS_RSA_PUBLIC, md_alg,
+                                  (unsigned int) hash_len, hash, sig ) ) != 0 )
+        return( ret );
+
+    /* The buffer contains a valid signature followed by extra data.
+     * We have a special error code for that so that so that callers can
+     * use mbedtls_pk_verify() to check "Does the buffer start with a
+     * valid signature?" and not just "Does the buffer contain a valid
+     * signature?". */
+    if( sig_len > rsa_len )
+        return( MBEDTLS_ERR_PK_SIG_LEN_MISMATCH );
+
+    return( 0 );
+}
+
+static int rsa_sign_wrap( void *ctx, mbedtls_md_type_t md_alg,
+                   const unsigned char *hash, size_t hash_len,
+                   unsigned char *sig, size_t *sig_len,
+                   int (*f_rng)(void *, unsigned char *, size_t), void *p_rng )
+{
+    mbedtls_rsa_context * rsa = (mbedtls_rsa_context *) ctx;
+
+#if SIZE_MAX > UINT_MAX
+    if( md_alg == MBEDTLS_MD_NONE && UINT_MAX < hash_len )
+        return( MBEDTLS_ERR_PK_BAD_INPUT_DATA );
+#endif /* SIZE_MAX > UINT_MAX */
+
+    *sig_len = mbedtls_rsa_get_len( rsa );
+
+    return( mbedtls_rsa_pkcs1_sign( rsa, f_rng, p_rng, MBEDTLS_RSA_PRIVATE,
+                md_alg, (unsigned int) hash_len, hash, sig ) );
+}
+
+static int rsa_decrypt_wrap( void *ctx,
+                    const unsigned char *input, size_t ilen,
+                    unsigned char *output, size_t *olen, size_t osize,
+                    int (*f_rng)(void *, unsigned char *, size_t), void *p_rng )
+{
+    mbedtls_rsa_context * rsa = (mbedtls_rsa_context *) ctx;
+
+    if( ilen != mbedtls_rsa_get_len( rsa ) )
+        return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
+
+    return( mbedtls_rsa_pkcs1_decrypt( rsa, f_rng, p_rng,
+                MBEDTLS_RSA_PRIVATE, olen, input, output, osize ) );
+}
+
+static int rsa_encrypt_wrap( void *ctx,
+                    const unsigned char *input, size_t ilen,
+                    unsigned char *output, size_t *olen, size_t osize,
+                    int (*f_rng)(void *, unsigned char *, size_t), void *p_rng )
+{
+    mbedtls_rsa_context * rsa = (mbedtls_rsa_context *) ctx;
+    *olen = mbedtls_rsa_get_len( rsa );
+
+    if( *olen > osize )
+        return( MBEDTLS_ERR_RSA_OUTPUT_TOO_LARGE );
+
+    return( mbedtls_rsa_pkcs1_encrypt( rsa, f_rng, p_rng, MBEDTLS_RSA_PUBLIC,
+                                       ilen, input, output ) );
+}
+
+static int rsa_check_pair_wrap( const void *pub, const void *prv )
+{
+    return( mbedtls_rsa_check_pub_priv( (const mbedtls_rsa_context *) pub,
+                                (const mbedtls_rsa_context *) prv ) );
+}
+
+static void *rsa_alloc_wrap( void )
+{
+    void *ctx = mbedtls_calloc( 1, sizeof( mbedtls_rsa_context ) );
+
+    if( ctx != NULL )
+        mbedtls_rsa_init( (mbedtls_rsa_context *) ctx, 0, 0 );
+
+    return( ctx );
+}
+
+static void rsa_free_wrap( void *ctx )
+{
+    mbedtls_rsa_free( (mbedtls_rsa_context *) ctx );
+    mbedtls_free( ctx );
+}
+
+static void rsa_debug( const void *ctx, mbedtls_pk_debug_item *items )
+{
+    items->type = MBEDTLS_PK_DEBUG_MPI;
+    items->name = "rsa.N";
+    items->value = &( ((mbedtls_rsa_context *) ctx)->N );
+
+    items++;
+
+    items->type = MBEDTLS_PK_DEBUG_MPI;
+    items->name = "rsa.E";
+    items->value = &( ((mbedtls_rsa_context *) ctx)->E );
+}
+
+const mbedtls_pk_info_t mbedtls_rsa_info = {
+    MBEDTLS_PK_RSA,
+    "RSA",
+    rsa_get_bitlen,
+    rsa_can_do,
+    rsa_verify_wrap,
+    rsa_sign_wrap,
+#if defined(MBEDTLS_ECDSA_C) && defined(MBEDTLS_ECP_RESTARTABLE)
+    NULL,
+    NULL,
+#endif
+    rsa_decrypt_wrap,
+    rsa_encrypt_wrap,
+    rsa_check_pair_wrap,
+    rsa_alloc_wrap,
+    rsa_free_wrap,
+#if defined(MBEDTLS_ECDSA_C) && defined(MBEDTLS_ECP_RESTARTABLE)
+    NULL,
+    NULL,
+#endif
+    rsa_debug,
+};
+#endif /* MBEDTLS_RSA_C */
+
+#if defined(MBEDTLS_ECP_C)
+/*
+ * Generic EC key
+ */
+static int eckey_can_do( mbedtls_pk_type_t type )
+{
+    return( type == MBEDTLS_PK_ECKEY ||
+            type == MBEDTLS_PK_ECKEY_DH ||
+            type == MBEDTLS_PK_ECDSA );
+}
+
+static size_t eckey_get_bitlen( const void *ctx )
+{
+    return( ((mbedtls_ecp_keypair *) ctx)->grp.pbits );
+}
+
+#if defined(MBEDTLS_ECDSA_C)
+/* Forward declarations */
+static int ecdsa_verify_wrap( void *ctx, mbedtls_md_type_t md_alg,
+                       const unsigned char *hash, size_t hash_len,
+                       const unsigned char *sig, size_t sig_len );
+
+static int ecdsa_sign_wrap( void *ctx, mbedtls_md_type_t md_alg,
+                   const unsigned char *hash, size_t hash_len,
+                   unsigned char *sig, size_t *sig_len,
+                   int (*f_rng)(void *, unsigned char *, size_t), void *p_rng );
+
+static int eckey_verify_wrap( void *ctx, mbedtls_md_type_t md_alg,
+                       const unsigned char *hash, size_t hash_len,
+                       const unsigned char *sig, size_t sig_len )
+{
+    int ret;
+    mbedtls_ecdsa_context ecdsa;
+
+    mbedtls_ecdsa_init( &ecdsa );
+
+    if( ( ret = mbedtls_ecdsa_from_keypair( &ecdsa, ctx ) ) == 0 )
+        ret = ecdsa_verify_wrap( &ecdsa, md_alg, hash, hash_len, sig, sig_len );
+
+    mbedtls_ecdsa_free( &ecdsa );
+
+    return( ret );
+}
+
+static int eckey_sign_wrap( void *ctx, mbedtls_md_type_t md_alg,
+                   const unsigned char *hash, size_t hash_len,
+                   unsigned char *sig, size_t *sig_len,
+                   int (*f_rng)(void *, unsigned char *, size_t), void *p_rng )
+{
+    int ret;
+    mbedtls_ecdsa_context ecdsa;
+
+    mbedtls_ecdsa_init( &ecdsa );
+
+    if( ( ret = mbedtls_ecdsa_from_keypair( &ecdsa, ctx ) ) == 0 )
+        ret = ecdsa_sign_wrap( &ecdsa, md_alg, hash, hash_len, sig, sig_len,
+                               f_rng, p_rng );
+
+    mbedtls_ecdsa_free( &ecdsa );
+
+    return( ret );
+}
+
+#if defined(MBEDTLS_ECP_RESTARTABLE)
+/* Forward declarations */
+static int ecdsa_verify_rs_wrap( void *ctx, mbedtls_md_type_t md_alg,
+                       const unsigned char *hash, size_t hash_len,
+                       const unsigned char *sig, size_t sig_len,
+                       void *rs_ctx );
+
+static int ecdsa_sign_rs_wrap( void *ctx, mbedtls_md_type_t md_alg,
+                   const unsigned char *hash, size_t hash_len,
+                   unsigned char *sig, size_t *sig_len,
+                   int (*f_rng)(void *, unsigned char *, size_t), void *p_rng,
+                   void *rs_ctx );
+
+/*
+ * Restart context for ECDSA operations with ECKEY context
+ *
+ * We need to store an actual ECDSA context, as we need to pass the same to
+ * the underlying ecdsa function, so we can't create it on the fly every time.
+ */
+typedef struct
+{
+    mbedtls_ecdsa_restart_ctx ecdsa_rs;
+    mbedtls_ecdsa_context ecdsa_ctx;
+} eckey_restart_ctx;
+
+static void *eckey_rs_alloc( void )
+{
+    eckey_restart_ctx *rs_ctx;
+
+    void *ctx = mbedtls_calloc( 1, sizeof( eckey_restart_ctx ) );
+
+    if( ctx != NULL )
+    {
+        rs_ctx = ctx;
+        mbedtls_ecdsa_restart_init( &rs_ctx->ecdsa_rs );
+        mbedtls_ecdsa_init( &rs_ctx->ecdsa_ctx );
+    }
+
+    return( ctx );
+}
+
+static void eckey_rs_free( void *ctx )
+{
+    eckey_restart_ctx *rs_ctx;
+
+    if( ctx == NULL)
+        return;
+
+    rs_ctx = ctx;
+    mbedtls_ecdsa_restart_free( &rs_ctx->ecdsa_rs );
+    mbedtls_ecdsa_free( &rs_ctx->ecdsa_ctx );
+
+    mbedtls_free( ctx );
+}
+
+static int eckey_verify_rs_wrap( void *ctx, mbedtls_md_type_t md_alg,
+                       const unsigned char *hash, size_t hash_len,
+                       const unsigned char *sig, size_t sig_len,
+                       void *rs_ctx )
+{
+    int ret;
+    eckey_restart_ctx *rs = rs_ctx;
+
+    /* Should never happen */
+    if( rs == NULL )
+        return( MBEDTLS_ERR_PK_BAD_INPUT_DATA );
+
+    /* set up our own sub-context if needed (that is, on first run) */
+    if( rs->ecdsa_ctx.grp.pbits == 0 )
+        MBEDTLS_MPI_CHK( mbedtls_ecdsa_from_keypair( &rs->ecdsa_ctx, ctx ) );
+
+    MBEDTLS_MPI_CHK( ecdsa_verify_rs_wrap( &rs->ecdsa_ctx,
+                                           md_alg, hash, hash_len,
+                                           sig, sig_len, &rs->ecdsa_rs ) );
+
+cleanup:
+    return( ret );
+}
+
+static int eckey_sign_rs_wrap( void *ctx, mbedtls_md_type_t md_alg,
+                   const unsigned char *hash, size_t hash_len,
+                   unsigned char *sig, size_t *sig_len,
+                   int (*f_rng)(void *, unsigned char *, size_t), void *p_rng,
+                       void *rs_ctx )
+{
+    int ret;
+    eckey_restart_ctx *rs = rs_ctx;
+
+    /* Should never happen */
+    if( rs == NULL )
+        return( MBEDTLS_ERR_PK_BAD_INPUT_DATA );
+
+    /* set up our own sub-context if needed (that is, on first run) */
+    if( rs->ecdsa_ctx.grp.pbits == 0 )
+        MBEDTLS_MPI_CHK( mbedtls_ecdsa_from_keypair( &rs->ecdsa_ctx, ctx ) );
+
+    MBEDTLS_MPI_CHK( ecdsa_sign_rs_wrap( &rs->ecdsa_ctx, md_alg,
+                                         hash, hash_len, sig, sig_len,
+                                         f_rng, p_rng, &rs->ecdsa_rs ) );
+
+cleanup:
+    return( ret );
+}
+#endif /* MBEDTLS_ECP_RESTARTABLE */
+#endif /* MBEDTLS_ECDSA_C */
+
+static int eckey_check_pair( const void *pub, const void *prv )
+{
+    return( mbedtls_ecp_check_pub_priv( (const mbedtls_ecp_keypair *) pub,
+                                (const mbedtls_ecp_keypair *) prv ) );
+}
+
+static void *eckey_alloc_wrap( void )
+{
+    void *ctx = mbedtls_calloc( 1, sizeof( mbedtls_ecp_keypair ) );
+
+    if( ctx != NULL )
+        mbedtls_ecp_keypair_init( ctx );
+
+    return( ctx );
+}
+
+static void eckey_free_wrap( void *ctx )
+{
+    mbedtls_ecp_keypair_free( (mbedtls_ecp_keypair *) ctx );
+    mbedtls_free( ctx );
+}
+
+static void eckey_debug( const void *ctx, mbedtls_pk_debug_item *items )
+{
+    items->type = MBEDTLS_PK_DEBUG_ECP;
+    items->name = "eckey.Q";
+    items->value = &( ((mbedtls_ecp_keypair *) ctx)->Q );
+}
+
+const mbedtls_pk_info_t mbedtls_eckey_info = {
+    MBEDTLS_PK_ECKEY,
+    "EC",
+    eckey_get_bitlen,
+    eckey_can_do,
+#if defined(MBEDTLS_ECDSA_C)
+    eckey_verify_wrap,
+    eckey_sign_wrap,
+#if defined(MBEDTLS_ECP_RESTARTABLE)
+    eckey_verify_rs_wrap,
+    eckey_sign_rs_wrap,
+#endif
+#else /* MBEDTLS_ECDSA_C */
+    NULL,
+    NULL,
+#endif /* MBEDTLS_ECDSA_C */
+    NULL,
+    NULL,
+    eckey_check_pair,
+    eckey_alloc_wrap,
+    eckey_free_wrap,
+#if defined(MBEDTLS_ECDSA_C) && defined(MBEDTLS_ECP_RESTARTABLE)
+    eckey_rs_alloc,
+    eckey_rs_free,
+#endif
+    eckey_debug,
+};
+
+/*
+ * EC key restricted to ECDH
+ */
+static int eckeydh_can_do( mbedtls_pk_type_t type )
+{
+    return( type == MBEDTLS_PK_ECKEY ||
+            type == MBEDTLS_PK_ECKEY_DH );
+}
+
+const mbedtls_pk_info_t mbedtls_eckeydh_info = {
+    MBEDTLS_PK_ECKEY_DH,
+    "EC_DH",
+    eckey_get_bitlen,         /* Same underlying key structure */
+    eckeydh_can_do,
+    NULL,
+    NULL,
+#if defined(MBEDTLS_ECDSA_C) && defined(MBEDTLS_ECP_RESTARTABLE)
+    NULL,
+    NULL,
+#endif
+    NULL,
+    NULL,
+    eckey_check_pair,
+    eckey_alloc_wrap,       /* Same underlying key structure */
+    eckey_free_wrap,        /* Same underlying key structure */
+#if defined(MBEDTLS_ECDSA_C) && defined(MBEDTLS_ECP_RESTARTABLE)
+    NULL,
+    NULL,
+#endif
+    eckey_debug,            /* Same underlying key structure */
+};
+#endif /* MBEDTLS_ECP_C */
+
+#if defined(MBEDTLS_ECDSA_C)
+static int ecdsa_can_do( mbedtls_pk_type_t type )
+{
+    return( type == MBEDTLS_PK_ECDSA );
+}
+
+#if defined(MBEDTLS_USE_PSA_CRYPTO)
+/*
+ * An ASN.1 encoded signature is a sequence of two ASN.1 integers. Parse one of
+ * those integers and convert it to the fixed-length encoding expected by PSA.
+ */
+static int extract_ecdsa_sig_int( unsigned char **from, const unsigned char *end,
+                                  unsigned char *to, size_t to_len )
+{
+    int ret;
+    size_t unpadded_len, padding_len;
+
+    if( ( ret = mbedtls_asn1_get_tag( from, end, &unpadded_len,
+                                      MBEDTLS_ASN1_INTEGER ) ) != 0 )
+    {
+        return( ret );
+    }
+
+    while( unpadded_len > 0 && **from == 0x00 )
+    {
+        ( *from )++;
+        unpadded_len--;
+    }
+
+    if( unpadded_len > to_len || unpadded_len == 0 )
+        return( MBEDTLS_ERR_ASN1_LENGTH_MISMATCH );
+
+    padding_len = to_len - unpadded_len;
+    memset( to, 0x00, padding_len );
+    memcpy( to + padding_len, *from, unpadded_len );
+    ( *from ) += unpadded_len;
+
+    return( 0 );
+}
+
+/*
+ * Convert a signature from an ASN.1 sequence of two integers
+ * to a raw {r,s} buffer. Note: the provided sig buffer must be at least
+ * twice as big as int_size.
+ */
+static int extract_ecdsa_sig( unsigned char **p, const unsigned char *end,
+                              unsigned char *sig, size_t int_size )
+{
+    int ret;
+    size_t tmp_size;
+
+    if( ( ret = mbedtls_asn1_get_tag( p, end, &tmp_size,
+                MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ) ) != 0 )
+        return( ret );
+
+    /* Extract r */
+    if( ( ret = extract_ecdsa_sig_int( p, end, sig, int_size ) ) != 0 )
+        return( ret );
+    /* Extract s */
+    if( ( ret = extract_ecdsa_sig_int( p, end, sig + int_size, int_size ) ) != 0 )
+        return( ret );
+
+    return( 0 );
+}
+
+static int ecdsa_verify_wrap( void *ctx, mbedtls_md_type_t md_alg,
+                       const unsigned char *hash, size_t hash_len,
+                       const unsigned char *sig, size_t sig_len )
+{
+    int ret;
+    psa_key_handle_t key_slot;
+    psa_key_policy_t policy;
+    psa_key_type_t psa_type;
+    mbedtls_pk_context key;
+    int key_len;
+    /* see ECP_PUB_DER_MAX_BYTES in pkwrite.c */
+    unsigned char buf[30 + 2 * MBEDTLS_ECP_MAX_BYTES];
+    unsigned char *p;
+    mbedtls_pk_info_t pk_info = mbedtls_eckey_info;
+    psa_algorithm_t psa_sig_md, psa_md;
+    psa_ecc_curve_t curve = mbedtls_psa_translate_ecc_group(
+                            ( (mbedtls_ecdsa_context *) ctx )->grp.id );
+    const size_t signature_part_size = ( ( (mbedtls_ecdsa_context *) ctx )->grp.nbits + 7 ) / 8;
+
+    if( curve == 0 )
+        return( MBEDTLS_ERR_PK_BAD_INPUT_DATA );
+
+    /* mbedtls_pk_write_pubkey() expects a full PK context;
+     * re-construct one to make it happy */
+    key.pk_info = &pk_info;
+    key.pk_ctx = ctx;
+    p = buf + sizeof( buf );
+    key_len = mbedtls_pk_write_pubkey( &p, buf, &key );
+    if( key_len <= 0 )
+        return( MBEDTLS_ERR_PK_BAD_INPUT_DATA );
+
+    psa_md = mbedtls_psa_translate_md( md_alg );
+    if( psa_md == 0 )
+        return( MBEDTLS_ERR_PK_BAD_INPUT_DATA );
+    psa_sig_md = PSA_ALG_ECDSA( psa_md );
+    psa_type = PSA_KEY_TYPE_ECC_PUBLIC_KEY( curve );
+
+    if( ( ret = psa_allocate_key( &key_slot ) ) != PSA_SUCCESS )
+          return( mbedtls_psa_err_translate_pk( ret ) );
+
+    policy = psa_key_policy_init();
+    psa_key_policy_set_usage( &policy, PSA_KEY_USAGE_VERIFY, psa_sig_md );
+    if( ( ret = psa_set_key_policy( key_slot, &policy ) ) != PSA_SUCCESS )
+    {
+        ret = mbedtls_psa_err_translate_pk( ret );
+        goto cleanup;
+    }
+
+    if( psa_import_key( key_slot, psa_type, buf + sizeof( buf ) - key_len, key_len )
+         != PSA_SUCCESS )
+    {
+        ret = MBEDTLS_ERR_PK_BAD_INPUT_DATA;
+        goto cleanup;
+    }
+
+    /* We don't need the exported key anymore and can
+     * reuse its buffer for signature extraction. */
+    if( 2 * signature_part_size > sizeof( buf ) )
+    {
+        ret = MBEDTLS_ERR_PK_BAD_INPUT_DATA;
+        goto cleanup;
+    }
+
+    p = (unsigned char*) sig;
+    if( ( ret = extract_ecdsa_sig( &p, sig + sig_len, buf,
+                                   signature_part_size ) ) != 0 )
+    {
+        goto cleanup;
+    }
+
+    if( psa_asymmetric_verify( key_slot, psa_sig_md,
+                               hash, hash_len,
+                               buf, 2 * signature_part_size )
+         != PSA_SUCCESS )
+    {
+         ret = MBEDTLS_ERR_ECP_VERIFY_FAILED;
+         goto cleanup;
+    }
+
+    if( p != sig + sig_len )
+    {
+        ret = MBEDTLS_ERR_PK_SIG_LEN_MISMATCH;
+        goto cleanup;
+    }
+    ret = 0;
+
+cleanup:
+    psa_destroy_key( key_slot );
+    return( ret );
+}
+#else /* MBEDTLS_USE_PSA_CRYPTO */
+static int ecdsa_verify_wrap( void *ctx, mbedtls_md_type_t md_alg,
+                       const unsigned char *hash, size_t hash_len,
+                       const unsigned char *sig, size_t sig_len )
+{
+    int ret;
+    ((void) md_alg);
+
+    ret = mbedtls_ecdsa_read_signature( (mbedtls_ecdsa_context *) ctx,
+                                hash, hash_len, sig, sig_len );
+
+    if( ret == MBEDTLS_ERR_ECP_SIG_LEN_MISMATCH )
+        return( MBEDTLS_ERR_PK_SIG_LEN_MISMATCH );
+
+    return( ret );
+}
+#endif /* MBEDTLS_USE_PSA_CRYPTO */
+
+static int ecdsa_sign_wrap( void *ctx, mbedtls_md_type_t md_alg,
+                   const unsigned char *hash, size_t hash_len,
+                   unsigned char *sig, size_t *sig_len,
+                   int (*f_rng)(void *, unsigned char *, size_t), void *p_rng )
+{
+    return( mbedtls_ecdsa_write_signature( (mbedtls_ecdsa_context *) ctx,
+                md_alg, hash, hash_len, sig, sig_len, f_rng, p_rng ) );
+}
+
+#if defined(MBEDTLS_ECP_RESTARTABLE)
+static int ecdsa_verify_rs_wrap( void *ctx, mbedtls_md_type_t md_alg,
+                       const unsigned char *hash, size_t hash_len,
+                       const unsigned char *sig, size_t sig_len,
+                       void *rs_ctx )
+{
+    int ret;
+    ((void) md_alg);
+
+    ret = mbedtls_ecdsa_read_signature_restartable(
+            (mbedtls_ecdsa_context *) ctx,
+            hash, hash_len, sig, sig_len,
+            (mbedtls_ecdsa_restart_ctx *) rs_ctx );
+
+    if( ret == MBEDTLS_ERR_ECP_SIG_LEN_MISMATCH )
+        return( MBEDTLS_ERR_PK_SIG_LEN_MISMATCH );
+
+    return( ret );
+}
+
+static int ecdsa_sign_rs_wrap( void *ctx, mbedtls_md_type_t md_alg,
+                   const unsigned char *hash, size_t hash_len,
+                   unsigned char *sig, size_t *sig_len,
+                   int (*f_rng)(void *, unsigned char *, size_t), void *p_rng,
+                   void *rs_ctx )
+{
+    return( mbedtls_ecdsa_write_signature_restartable(
+                (mbedtls_ecdsa_context *) ctx,
+                md_alg, hash, hash_len, sig, sig_len, f_rng, p_rng,
+                (mbedtls_ecdsa_restart_ctx *) rs_ctx ) );
+
+}
+#endif /* MBEDTLS_ECP_RESTARTABLE */
+
+static void *ecdsa_alloc_wrap( void )
+{
+    void *ctx = mbedtls_calloc( 1, sizeof( mbedtls_ecdsa_context ) );
+
+    if( ctx != NULL )
+        mbedtls_ecdsa_init( (mbedtls_ecdsa_context *) ctx );
+
+    return( ctx );
+}
+
+static void ecdsa_free_wrap( void *ctx )
+{
+    mbedtls_ecdsa_free( (mbedtls_ecdsa_context *) ctx );
+    mbedtls_free( ctx );
+}
+
+#if defined(MBEDTLS_ECP_RESTARTABLE)
+static void *ecdsa_rs_alloc( void )
+{
+    void *ctx = mbedtls_calloc( 1, sizeof( mbedtls_ecdsa_restart_ctx ) );
+
+    if( ctx != NULL )
+        mbedtls_ecdsa_restart_init( ctx );
+
+    return( ctx );
+}
+
+static void ecdsa_rs_free( void *ctx )
+{
+    mbedtls_ecdsa_restart_free( ctx );
+    mbedtls_free( ctx );
+}
+#endif /* MBEDTLS_ECP_RESTARTABLE */
+
+const mbedtls_pk_info_t mbedtls_ecdsa_info = {
+    MBEDTLS_PK_ECDSA,
+    "ECDSA",
+    eckey_get_bitlen,     /* Compatible key structures */
+    ecdsa_can_do,
+    ecdsa_verify_wrap,
+    ecdsa_sign_wrap,
+#if defined(MBEDTLS_ECP_RESTARTABLE)
+    ecdsa_verify_rs_wrap,
+    ecdsa_sign_rs_wrap,
+#endif
+    NULL,
+    NULL,
+    eckey_check_pair,   /* Compatible key structures */
+    ecdsa_alloc_wrap,
+    ecdsa_free_wrap,
+#if defined(MBEDTLS_ECP_RESTARTABLE)
+    ecdsa_rs_alloc,
+    ecdsa_rs_free,
+#endif
+    eckey_debug,        /* Compatible key structures */
+};
+#endif /* MBEDTLS_ECDSA_C */
+
+#if defined(MBEDTLS_PK_RSA_ALT_SUPPORT)
+/*
+ * Support for alternative RSA-private implementations
+ */
+
+static int rsa_alt_can_do( mbedtls_pk_type_t type )
+{
+    return( type == MBEDTLS_PK_RSA );
+}
+
+static size_t rsa_alt_get_bitlen( const void *ctx )
+{
+    const mbedtls_rsa_alt_context *rsa_alt = (const mbedtls_rsa_alt_context *) ctx;
+
+    return( 8 * rsa_alt->key_len_func( rsa_alt->key ) );
+}
+
+static int rsa_alt_sign_wrap( void *ctx, mbedtls_md_type_t md_alg,
+                   const unsigned char *hash, size_t hash_len,
+                   unsigned char *sig, size_t *sig_len,
+                   int (*f_rng)(void *, unsigned char *, size_t), void *p_rng )
+{
+    mbedtls_rsa_alt_context *rsa_alt = (mbedtls_rsa_alt_context *) ctx;
+
+#if SIZE_MAX > UINT_MAX
+    if( UINT_MAX < hash_len )
+        return( MBEDTLS_ERR_PK_BAD_INPUT_DATA );
+#endif /* SIZE_MAX > UINT_MAX */
+
+    *sig_len = rsa_alt->key_len_func( rsa_alt->key );
+
+    return( rsa_alt->sign_func( rsa_alt->key, f_rng, p_rng, MBEDTLS_RSA_PRIVATE,
+                md_alg, (unsigned int) hash_len, hash, sig ) );
+}
+
+static int rsa_alt_decrypt_wrap( void *ctx,
+                    const unsigned char *input, size_t ilen,
+                    unsigned char *output, size_t *olen, size_t osize,
+                    int (*f_rng)(void *, unsigned char *, size_t), void *p_rng )
+{
+    mbedtls_rsa_alt_context *rsa_alt = (mbedtls_rsa_alt_context *) ctx;
+
+    ((void) f_rng);
+    ((void) p_rng);
+
+    if( ilen != rsa_alt->key_len_func( rsa_alt->key ) )
+        return( MBEDTLS_ERR_RSA_BAD_INPUT_DATA );
+
+    return( rsa_alt->decrypt_func( rsa_alt->key,
+                MBEDTLS_RSA_PRIVATE, olen, input, output, osize ) );
+}
+
+#if defined(MBEDTLS_RSA_C)
+static int rsa_alt_check_pair( const void *pub, const void *prv )
+{
+    unsigned char sig[MBEDTLS_MPI_MAX_SIZE];
+    unsigned char hash[32];
+    size_t sig_len = 0;
+    int ret;
+
+    if( rsa_alt_get_bitlen( prv ) != rsa_get_bitlen( pub ) )
+        return( MBEDTLS_ERR_RSA_KEY_CHECK_FAILED );
+
+    memset( hash, 0x2a, sizeof( hash ) );
+
+    if( ( ret = rsa_alt_sign_wrap( (void *) prv, MBEDTLS_MD_NONE,
+                                   hash, sizeof( hash ),
+                                   sig, &sig_len, NULL, NULL ) ) != 0 )
+    {
+        return( ret );
+    }
+
+    if( rsa_verify_wrap( (void *) pub, MBEDTLS_MD_NONE,
+                         hash, sizeof( hash ), sig, sig_len ) != 0 )
+    {
+        return( MBEDTLS_ERR_RSA_KEY_CHECK_FAILED );
+    }
+
+    return( 0 );
+}
+#endif /* MBEDTLS_RSA_C */
+
+static void *rsa_alt_alloc_wrap( void )
+{
+    void *ctx = mbedtls_calloc( 1, sizeof( mbedtls_rsa_alt_context ) );
+
+    if( ctx != NULL )
+        memset( ctx, 0, sizeof( mbedtls_rsa_alt_context ) );
+
+    return( ctx );
+}
+
+static void rsa_alt_free_wrap( void *ctx )
+{
+    mbedtls_platform_zeroize( ctx, sizeof( mbedtls_rsa_alt_context ) );
+    mbedtls_free( ctx );
+}
+
+const mbedtls_pk_info_t mbedtls_rsa_alt_info = {
+    MBEDTLS_PK_RSA_ALT,
+    "RSA-alt",
+    rsa_alt_get_bitlen,
+    rsa_alt_can_do,
+    NULL,
+    rsa_alt_sign_wrap,
+#if defined(MBEDTLS_ECDSA_C) && defined(MBEDTLS_ECP_RESTARTABLE)
+    NULL,
+    NULL,
+#endif
+    rsa_alt_decrypt_wrap,
+    NULL,
+#if defined(MBEDTLS_RSA_C)
+    rsa_alt_check_pair,
+#else
+    NULL,
+#endif
+    rsa_alt_alloc_wrap,
+    rsa_alt_free_wrap,
+#if defined(MBEDTLS_ECDSA_C) && defined(MBEDTLS_ECP_RESTARTABLE)
+    NULL,
+    NULL,
+#endif
+    NULL,
+};
+
+#endif /* MBEDTLS_PK_RSA_ALT_SUPPORT */
+
+#if defined(MBEDTLS_USE_PSA_CRYPTO)
+
+static void *pk_opaque_alloc_wrap( void )
+{
+    void *ctx = mbedtls_calloc( 1, sizeof( psa_key_handle_t ) );
+
+    /* no _init() function to call, an calloc() already zeroized */
+
+    return( ctx );
+}
+
+static void pk_opaque_free_wrap( void *ctx )
+{
+    mbedtls_platform_zeroize( ctx, sizeof( psa_key_handle_t ) );
+    mbedtls_free( ctx );
+}
+
+static size_t pk_opaque_get_bitlen( const void *ctx )
+{
+    const psa_key_handle_t *key = (const psa_key_handle_t *) ctx;
+    size_t bits;
+
+    if( PSA_SUCCESS != psa_get_key_information( *key, NULL, &bits ) )
+        return( 0 );
+
+    return( bits );
+}
+
+static int pk_opaque_can_do( mbedtls_pk_type_t type )
+{
+    /* For now opaque PSA keys can only wrap ECC keypairs,
+     * as checked by setup_psa().
+     * Also, ECKEY_DH does not really make sense with the current API. */
+    return( type == MBEDTLS_PK_ECKEY ||
+            type == MBEDTLS_PK_ECDSA );
+}
+
+/*
+ * Simultaneously convert and move raw MPI from the beginning of a buffer
+ * to an ASN.1 MPI at the end of the buffer.
+ * See also mbedtls_asn1_write_mpi().
+ *
+ * p: pointer to the end of the output buffer
+ * start: start of the output buffer, and also of the mpi to write at the end
+ * n_len: length of the mpi to read from start
+ */
+static int asn1_write_mpibuf( unsigned char **p, unsigned char *start,
+                              size_t n_len )
+{
+    int ret;
+    size_t len = 0;
+
+    if( (size_t)( *p - start ) < n_len )
+        return( MBEDTLS_ERR_ASN1_BUF_TOO_SMALL );
+
+    len = n_len;
+    *p -= len;
+    memmove( *p, start, len );
+
+    /* ASN.1 DER encoding requires minimal length, so skip leading 0s.
+     * Neither r nor s should be 0, but as a failsafe measure, still detect
+     * that rather than overflowing the buffer in case of a PSA error. */
+    while( len > 0 && **p == 0x00 )
+    {
+        ++(*p);
+        --len;
+    }
+
+    /* this is only reached if the signature was invalid */
+    if( len == 0 )
+        return( MBEDTLS_ERR_PK_HW_ACCEL_FAILED );
+
+    /* if the msb is 1, ASN.1 requires that we prepend a 0.
+     * Neither r nor s can be 0, so we can assume len > 0 at all times. */
+    if( **p & 0x80 )
+    {
+        if( *p - start < 1 )
+            return( MBEDTLS_ERR_ASN1_BUF_TOO_SMALL );
+
+        *--(*p) = 0x00;
+        len += 1;
+    }
+
+    MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_len( p, start, len ) );
+    MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_tag( p, start,
+                                                MBEDTLS_ASN1_INTEGER ) );
+
+    return( (int) len );
+}
+
+/* Transcode signature from PSA format to ASN.1 sequence.
+ * See ecdsa_signature_to_asn1 in ecdsa.c, but with byte buffers instead of
+ * MPIs, and in-place.
+ *
+ * [in/out] sig: the signature pre- and post-transcoding
+ * [in/out] sig_len: signature length pre- and post-transcoding
+ * [int] buf_len: the available size the in/out buffer
+ */
+static int pk_ecdsa_sig_asn1_from_psa( unsigned char *sig, size_t *sig_len,
+                                       size_t buf_len )
+{
+    int ret;
+    size_t len = 0;
+    const size_t rs_len = *sig_len / 2;
+    unsigned char *p = sig + buf_len;
+
+    MBEDTLS_ASN1_CHK_ADD( len, asn1_write_mpibuf( &p, sig + rs_len, rs_len ) );
+    MBEDTLS_ASN1_CHK_ADD( len, asn1_write_mpibuf( &p, sig, rs_len ) );
+
+    MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_len( &p, sig, len ) );
+    MBEDTLS_ASN1_CHK_ADD( len, mbedtls_asn1_write_tag( &p, sig,
+                          MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ) );
+
+    memmove( sig, p, len );
+    *sig_len = len;
+
+    return( 0 );
+}
+
+static int pk_opaque_sign_wrap( void *ctx, mbedtls_md_type_t md_alg,
+                   const unsigned char *hash, size_t hash_len,
+                   unsigned char *sig, size_t *sig_len,
+                   int (*f_rng)(void *, unsigned char *, size_t), void *p_rng )
+{
+    const psa_key_handle_t *key = (const psa_key_handle_t *) ctx;
+    psa_algorithm_t alg = PSA_ALG_ECDSA( mbedtls_psa_translate_md( md_alg ) );
+    size_t bits, buf_len;
+    psa_status_t status;
+
+    /* PSA has its own RNG */
+    (void) f_rng;
+    (void) p_rng;
+
+    /* PSA needs an output buffer of known size, but our API doesn't provide
+     * that information. Assume that the buffer is large enough for a
+     * maximal-length signature with that key (otherwise the application is
+     * buggy anyway). */
+    status = psa_get_key_information( *key, NULL, &bits );
+    if( status != PSA_SUCCESS )
+        return( mbedtls_psa_err_translate_pk( status ) );
+
+    buf_len = MBEDTLS_ECDSA_MAX_SIG_LEN( bits );
+
+    /* make the signature */
+    status = psa_asymmetric_sign( *key, alg, hash, hash_len,
+                                        sig, buf_len, sig_len );
+    if( status != PSA_SUCCESS )
+        return( mbedtls_psa_err_translate_pk( status ) );
+
+    /* transcode it to ASN.1 sequence */
+    return( pk_ecdsa_sig_asn1_from_psa( sig, sig_len, buf_len ) );
+}
+
+const mbedtls_pk_info_t mbedtls_pk_opaque_info = {
+    MBEDTLS_PK_OPAQUE,
+    "Opaque",
+    pk_opaque_get_bitlen,
+    pk_opaque_can_do,
+    NULL, /* verify - will be done later */
+    pk_opaque_sign_wrap,
+#if defined(MBEDTLS_ECDSA_C) && defined(MBEDTLS_ECP_RESTARTABLE)
+    NULL, /* restartable verify - not relevant */
+    NULL, /* restartable sign - not relevant */
+#endif
+    NULL, /* decrypt - will be done later */
+    NULL, /* encrypt - will be done later */
+    NULL, /* check_pair - could be done later or left NULL */
+    pk_opaque_alloc_wrap,
+    pk_opaque_free_wrap,
+#if defined(MBEDTLS_ECDSA_C) && defined(MBEDTLS_ECP_RESTARTABLE)
+    NULL, /* restart alloc - not relevant */
+    NULL, /* restart free - not relevant */
+#endif
+    NULL, /* debug - could be done later, or even left NULL */
+};
+
+#endif /* MBEDTLS_USE_PSA_CRYPTO */
+
+#endif /* MBEDTLS_PK_C */