mbed os with nrf51 internal bandgap enabled to read battery level

Dependents:   BLE_file_test BLE_Blink ExternalEncoder

Revision:
0:f269e3021894
diff -r 000000000000 -r f269e3021894 features/mbedtls/src/pkparse.c
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/features/mbedtls/src/pkparse.c	Sun Oct 23 15:10:02 2016 +0000
@@ -0,0 +1,1293 @@
+/*
+ *  Public Key layer for parsing key files and structures
+ *
+ *  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_PARSE_C)
+
+#include "mbedtls/pk.h"
+#include "mbedtls/asn1.h"
+#include "mbedtls/oid.h"
+
+#include <string.h>
+
+#if defined(MBEDTLS_RSA_C)
+#include "mbedtls/rsa.h"
+#endif
+#if defined(MBEDTLS_ECP_C)
+#include "mbedtls/ecp.h"
+#endif
+#if defined(MBEDTLS_ECDSA_C)
+#include "mbedtls/ecdsa.h"
+#endif
+#if defined(MBEDTLS_PEM_PARSE_C)
+#include "mbedtls/pem.h"
+#endif
+#if defined(MBEDTLS_PKCS5_C)
+#include "mbedtls/pkcs5.h"
+#endif
+#if defined(MBEDTLS_PKCS12_C)
+#include "mbedtls/pkcs12.h"
+#endif
+
+#if defined(MBEDTLS_PLATFORM_C)
+#include "mbedtls/platform.h"
+#else
+#include <stdlib.h>
+#define mbedtls_calloc    calloc
+#define mbedtls_free       free
+#endif
+
+#if defined(MBEDTLS_FS_IO)
+/* Implementation that should never be optimized out by the compiler */
+static void mbedtls_zeroize( void *v, size_t n ) {
+    volatile unsigned char *p = v; while( n-- ) *p++ = 0;
+}
+
+/*
+ * Load all data from a file into a given buffer.
+ *
+ * The file is expected to contain either PEM or DER encoded data.
+ * A terminating null byte is always appended. It is included in the announced
+ * length only if the data looks like it is PEM encoded.
+ */
+int mbedtls_pk_load_file( const char *path, unsigned char **buf, size_t *n )
+{
+    FILE *f;
+    long size;
+
+    if( ( f = fopen( path, "rb" ) ) == NULL )
+        return( MBEDTLS_ERR_PK_FILE_IO_ERROR );
+
+    fseek( f, 0, SEEK_END );
+    if( ( size = ftell( f ) ) == -1 )
+    {
+        fclose( f );
+        return( MBEDTLS_ERR_PK_FILE_IO_ERROR );
+    }
+    fseek( f, 0, SEEK_SET );
+
+    *n = (size_t) size;
+
+    if( *n + 1 == 0 ||
+        ( *buf = mbedtls_calloc( 1, *n + 1 ) ) == NULL )
+    {
+        fclose( f );
+        return( MBEDTLS_ERR_PK_ALLOC_FAILED );
+    }
+
+    if( fread( *buf, 1, *n, f ) != *n )
+    {
+        fclose( f );
+        mbedtls_free( *buf );
+        return( MBEDTLS_ERR_PK_FILE_IO_ERROR );
+    }
+
+    fclose( f );
+
+    (*buf)[*n] = '\0';
+
+    if( strstr( (const char *) *buf, "-----BEGIN " ) != NULL )
+        ++*n;
+
+    return( 0 );
+}
+
+/*
+ * Load and parse a private key
+ */
+int mbedtls_pk_parse_keyfile( mbedtls_pk_context *ctx,
+                      const char *path, const char *pwd )
+{
+    int ret;
+    size_t n;
+    unsigned char *buf;
+
+    if( ( ret = mbedtls_pk_load_file( path, &buf, &n ) ) != 0 )
+        return( ret );
+
+    if( pwd == NULL )
+        ret = mbedtls_pk_parse_key( ctx, buf, n, NULL, 0 );
+    else
+        ret = mbedtls_pk_parse_key( ctx, buf, n,
+                (const unsigned char *) pwd, strlen( pwd ) );
+
+    mbedtls_zeroize( buf, n );
+    mbedtls_free( buf );
+
+    return( ret );
+}
+
+/*
+ * Load and parse a public key
+ */
+int mbedtls_pk_parse_public_keyfile( mbedtls_pk_context *ctx, const char *path )
+{
+    int ret;
+    size_t n;
+    unsigned char *buf;
+
+    if( ( ret = mbedtls_pk_load_file( path, &buf, &n ) ) != 0 )
+        return( ret );
+
+    ret = mbedtls_pk_parse_public_key( ctx, buf, n );
+
+    mbedtls_zeroize( buf, n );
+    mbedtls_free( buf );
+
+    return( ret );
+}
+#endif /* MBEDTLS_FS_IO */
+
+#if defined(MBEDTLS_ECP_C)
+/* Minimally parse an ECParameters buffer to and mbedtls_asn1_buf
+ *
+ * ECParameters ::= CHOICE {
+ *   namedCurve         OBJECT IDENTIFIER
+ *   specifiedCurve     SpecifiedECDomain -- = SEQUENCE { ... }
+ *   -- implicitCurve   NULL
+ * }
+ */
+static int pk_get_ecparams( unsigned char **p, const unsigned char *end,
+                            mbedtls_asn1_buf *params )
+{
+    int ret;
+
+    /* Tag may be either OID or SEQUENCE */
+    params->tag = **p;
+    if( params->tag != MBEDTLS_ASN1_OID
+#if defined(MBEDTLS_PK_PARSE_EC_EXTENDED)
+            && params->tag != ( MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE )
+#endif
+            )
+    {
+        return( MBEDTLS_ERR_PK_KEY_INVALID_FORMAT +
+                MBEDTLS_ERR_ASN1_UNEXPECTED_TAG );
+    }
+
+    if( ( ret = mbedtls_asn1_get_tag( p, end, &params->len, params->tag ) ) != 0 )
+    {
+        return( MBEDTLS_ERR_PK_KEY_INVALID_FORMAT + ret );
+    }
+
+    params->p = *p;
+    *p += params->len;
+
+    if( *p != end )
+        return( MBEDTLS_ERR_PK_KEY_INVALID_FORMAT +
+                MBEDTLS_ERR_ASN1_LENGTH_MISMATCH );
+
+    return( 0 );
+}
+
+#if defined(MBEDTLS_PK_PARSE_EC_EXTENDED)
+/*
+ * Parse a SpecifiedECDomain (SEC 1 C.2) and (mostly) fill the group with it.
+ * WARNING: the resulting group should only be used with
+ * pk_group_id_from_specified(), since its base point may not be set correctly
+ * if it was encoded compressed.
+ *
+ *  SpecifiedECDomain ::= SEQUENCE {
+ *      version SpecifiedECDomainVersion(ecdpVer1 | ecdpVer2 | ecdpVer3, ...),
+ *      fieldID FieldID {{FieldTypes}},
+ *      curve Curve,
+ *      base ECPoint,
+ *      order INTEGER,
+ *      cofactor INTEGER OPTIONAL,
+ *      hash HashAlgorithm OPTIONAL,
+ *      ...
+ *  }
+ *
+ * We only support prime-field as field type, and ignore hash and cofactor.
+ */
+static int pk_group_from_specified( const mbedtls_asn1_buf *params, mbedtls_ecp_group *grp )
+{
+    int ret;
+    unsigned char *p = params->p;
+    const unsigned char * const end = params->p + params->len;
+    const unsigned char *end_field, *end_curve;
+    size_t len;
+    int ver;
+
+    /* SpecifiedECDomainVersion ::= INTEGER { 1, 2, 3 } */
+    if( ( ret = mbedtls_asn1_get_int( &p, end, &ver ) ) != 0 )
+        return( MBEDTLS_ERR_PK_KEY_INVALID_FORMAT + ret );
+
+    if( ver < 1 || ver > 3 )
+        return( MBEDTLS_ERR_PK_KEY_INVALID_FORMAT );
+
+    /*
+     * FieldID { FIELD-ID:IOSet } ::= SEQUENCE { -- Finite field
+     *       fieldType FIELD-ID.&id({IOSet}),
+     *       parameters FIELD-ID.&Type({IOSet}{@fieldType})
+     * }
+     */
+    if( ( ret = mbedtls_asn1_get_tag( &p, end, &len,
+            MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ) ) != 0 )
+        return( ret );
+
+    end_field = p + len;
+
+    /*
+     * FIELD-ID ::= TYPE-IDENTIFIER
+     * FieldTypes FIELD-ID ::= {
+     *       { Prime-p IDENTIFIED BY prime-field } |
+     *       { Characteristic-two IDENTIFIED BY characteristic-two-field }
+     * }
+     * prime-field OBJECT IDENTIFIER ::= { id-fieldType 1 }
+     */
+    if( ( ret = mbedtls_asn1_get_tag( &p, end_field, &len, MBEDTLS_ASN1_OID ) ) != 0 )
+        return( ret );
+
+    if( len != MBEDTLS_OID_SIZE( MBEDTLS_OID_ANSI_X9_62_PRIME_FIELD ) ||
+        memcmp( p, MBEDTLS_OID_ANSI_X9_62_PRIME_FIELD, len ) != 0 )
+    {
+        return( MBEDTLS_ERR_PK_FEATURE_UNAVAILABLE );
+    }
+
+    p += len;
+
+    /* Prime-p ::= INTEGER -- Field of size p. */
+    if( ( ret = mbedtls_asn1_get_mpi( &p, end_field, &grp->P ) ) != 0 )
+        return( MBEDTLS_ERR_PK_KEY_INVALID_FORMAT + ret );
+
+    grp->pbits = mbedtls_mpi_bitlen( &grp->P );
+
+    if( p != end_field )
+        return( MBEDTLS_ERR_PK_KEY_INVALID_FORMAT +
+                MBEDTLS_ERR_ASN1_LENGTH_MISMATCH );
+
+    /*
+     * Curve ::= SEQUENCE {
+     *       a FieldElement,
+     *       b FieldElement,
+     *       seed BIT STRING OPTIONAL
+     *       -- Shall be present if used in SpecifiedECDomain
+     *       -- with version equal to ecdpVer2 or ecdpVer3
+     * }
+     */
+    if( ( ret = mbedtls_asn1_get_tag( &p, end, &len,
+            MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ) ) != 0 )
+        return( ret );
+
+    end_curve = p + len;
+
+    /*
+     * FieldElement ::= OCTET STRING
+     * containing an integer in the case of a prime field
+     */
+    if( ( ret = mbedtls_asn1_get_tag( &p, end_curve, &len, MBEDTLS_ASN1_OCTET_STRING ) ) != 0 ||
+        ( ret = mbedtls_mpi_read_binary( &grp->A, p, len ) ) != 0 )
+    {
+        return( MBEDTLS_ERR_PK_KEY_INVALID_FORMAT + ret );
+    }
+
+    p += len;
+
+    if( ( ret = mbedtls_asn1_get_tag( &p, end_curve, &len, MBEDTLS_ASN1_OCTET_STRING ) ) != 0 ||
+        ( ret = mbedtls_mpi_read_binary( &grp->B, p, len ) ) != 0 )
+    {
+        return( MBEDTLS_ERR_PK_KEY_INVALID_FORMAT + ret );
+    }
+
+    p += len;
+
+    /* Ignore seed BIT STRING OPTIONAL */
+    if( ( ret = mbedtls_asn1_get_tag( &p, end_curve, &len, MBEDTLS_ASN1_BIT_STRING ) ) == 0 )
+        p += len;
+
+    if( p != end_curve )
+        return( MBEDTLS_ERR_PK_KEY_INVALID_FORMAT +
+                MBEDTLS_ERR_ASN1_LENGTH_MISMATCH );
+
+    /*
+     * ECPoint ::= OCTET STRING
+     */
+    if( ( ret = mbedtls_asn1_get_tag( &p, end, &len, MBEDTLS_ASN1_OCTET_STRING ) ) != 0 )
+        return( MBEDTLS_ERR_PK_KEY_INVALID_FORMAT + ret );
+
+    if( ( ret = mbedtls_ecp_point_read_binary( grp, &grp->G,
+                                      ( const unsigned char *) p, len ) ) != 0 )
+    {
+        /*
+         * If we can't read the point because it's compressed, cheat by
+         * reading only the X coordinate and the parity bit of Y.
+         */
+        if( ret != MBEDTLS_ERR_ECP_FEATURE_UNAVAILABLE ||
+            ( p[0] != 0x02 && p[0] != 0x03 ) ||
+            len != mbedtls_mpi_size( &grp->P ) + 1 ||
+            mbedtls_mpi_read_binary( &grp->G.X, p + 1, len - 1 ) != 0 ||
+            mbedtls_mpi_lset( &grp->G.Y, p[0] - 2 ) != 0 ||
+            mbedtls_mpi_lset( &grp->G.Z, 1 ) != 0 )
+        {
+            return( MBEDTLS_ERR_PK_KEY_INVALID_FORMAT );
+        }
+    }
+
+    p += len;
+
+    /*
+     * order INTEGER
+     */
+    if( ( ret = mbedtls_asn1_get_mpi( &p, end, &grp->N ) ) != 0 )
+        return( MBEDTLS_ERR_PK_KEY_INVALID_FORMAT + ret );
+
+    grp->nbits = mbedtls_mpi_bitlen( &grp->N );
+
+    /*
+     * Allow optional elements by purposefully not enforcing p == end here.
+     */
+
+    return( 0 );
+}
+
+/*
+ * Find the group id associated with an (almost filled) group as generated by
+ * pk_group_from_specified(), or return an error if unknown.
+ */
+static int pk_group_id_from_group( const mbedtls_ecp_group *grp, mbedtls_ecp_group_id *grp_id )
+{
+    int ret = 0;
+    mbedtls_ecp_group ref;
+    const mbedtls_ecp_group_id *id;
+
+    mbedtls_ecp_group_init( &ref );
+
+    for( id = mbedtls_ecp_grp_id_list(); *id != MBEDTLS_ECP_DP_NONE; id++ )
+    {
+        /* Load the group associated to that id */
+        mbedtls_ecp_group_free( &ref );
+        MBEDTLS_MPI_CHK( mbedtls_ecp_group_load( &ref, *id ) );
+
+        /* Compare to the group we were given, starting with easy tests */
+        if( grp->pbits == ref.pbits && grp->nbits == ref.nbits &&
+            mbedtls_mpi_cmp_mpi( &grp->P, &ref.P ) == 0 &&
+            mbedtls_mpi_cmp_mpi( &grp->A, &ref.A ) == 0 &&
+            mbedtls_mpi_cmp_mpi( &grp->B, &ref.B ) == 0 &&
+            mbedtls_mpi_cmp_mpi( &grp->N, &ref.N ) == 0 &&
+            mbedtls_mpi_cmp_mpi( &grp->G.X, &ref.G.X ) == 0 &&
+            mbedtls_mpi_cmp_mpi( &grp->G.Z, &ref.G.Z ) == 0 &&
+            /* For Y we may only know the parity bit, so compare only that */
+            mbedtls_mpi_get_bit( &grp->G.Y, 0 ) == mbedtls_mpi_get_bit( &ref.G.Y, 0 ) )
+        {
+            break;
+        }
+
+    }
+
+cleanup:
+    mbedtls_ecp_group_free( &ref );
+
+    *grp_id = *id;
+
+    if( ret == 0 && *id == MBEDTLS_ECP_DP_NONE )
+        ret = MBEDTLS_ERR_ECP_FEATURE_UNAVAILABLE;
+
+    return( ret );
+}
+
+/*
+ * Parse a SpecifiedECDomain (SEC 1 C.2) and find the associated group ID
+ */
+static int pk_group_id_from_specified( const mbedtls_asn1_buf *params,
+                                       mbedtls_ecp_group_id *grp_id )
+{
+    int ret;
+    mbedtls_ecp_group grp;
+
+    mbedtls_ecp_group_init( &grp );
+
+    if( ( ret = pk_group_from_specified( params, &grp ) ) != 0 )
+        goto cleanup;
+
+    ret = pk_group_id_from_group( &grp, grp_id );
+
+cleanup:
+    mbedtls_ecp_group_free( &grp );
+
+    return( ret );
+}
+#endif /* MBEDTLS_PK_PARSE_EC_EXTENDED */
+
+/*
+ * Use EC parameters to initialise an EC group
+ *
+ * ECParameters ::= CHOICE {
+ *   namedCurve         OBJECT IDENTIFIER
+ *   specifiedCurve     SpecifiedECDomain -- = SEQUENCE { ... }
+ *   -- implicitCurve   NULL
+ */
+static int pk_use_ecparams( const mbedtls_asn1_buf *params, mbedtls_ecp_group *grp )
+{
+    int ret;
+    mbedtls_ecp_group_id grp_id;
+
+    if( params->tag == MBEDTLS_ASN1_OID )
+    {
+        if( mbedtls_oid_get_ec_grp( params, &grp_id ) != 0 )
+            return( MBEDTLS_ERR_PK_UNKNOWN_NAMED_CURVE );
+    }
+    else
+    {
+#if defined(MBEDTLS_PK_PARSE_EC_EXTENDED)
+        if( ( ret = pk_group_id_from_specified( params, &grp_id ) ) != 0 )
+            return( ret );
+#else
+        return( MBEDTLS_ERR_PK_KEY_INVALID_FORMAT );
+#endif
+    }
+
+    /*
+     * grp may already be initilialized; if so, make sure IDs match
+     */
+    if( grp->id != MBEDTLS_ECP_DP_NONE && grp->id != grp_id )
+        return( MBEDTLS_ERR_PK_KEY_INVALID_FORMAT );
+
+    if( ( ret = mbedtls_ecp_group_load( grp, grp_id ) ) != 0 )
+        return( ret );
+
+    return( 0 );
+}
+
+/*
+ * EC public key is an EC point
+ *
+ * The caller is responsible for clearing the structure upon failure if
+ * desired. Take care to pass along the possible ECP_FEATURE_UNAVAILABLE
+ * return code of mbedtls_ecp_point_read_binary() and leave p in a usable state.
+ */
+static int pk_get_ecpubkey( unsigned char **p, const unsigned char *end,
+                            mbedtls_ecp_keypair *key )
+{
+    int ret;
+
+    if( ( ret = mbedtls_ecp_point_read_binary( &key->grp, &key->Q,
+                    (const unsigned char *) *p, end - *p ) ) == 0 )
+    {
+        ret = mbedtls_ecp_check_pubkey( &key->grp, &key->Q );
+    }
+
+    /*
+     * We know mbedtls_ecp_point_read_binary consumed all bytes or failed
+     */
+    *p = (unsigned char *) end;
+
+    return( ret );
+}
+#endif /* MBEDTLS_ECP_C */
+
+#if defined(MBEDTLS_RSA_C)
+/*
+ *  RSAPublicKey ::= SEQUENCE {
+ *      modulus           INTEGER,  -- n
+ *      publicExponent    INTEGER   -- e
+ *  }
+ */
+static int pk_get_rsapubkey( unsigned char **p,
+                             const unsigned char *end,
+                             mbedtls_rsa_context *rsa )
+{
+    int ret;
+    size_t len;
+
+    if( ( ret = mbedtls_asn1_get_tag( p, end, &len,
+            MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ) ) != 0 )
+        return( MBEDTLS_ERR_PK_INVALID_PUBKEY + ret );
+
+    if( *p + len != end )
+        return( MBEDTLS_ERR_PK_INVALID_PUBKEY +
+                MBEDTLS_ERR_ASN1_LENGTH_MISMATCH );
+
+    if( ( ret = mbedtls_asn1_get_mpi( p, end, &rsa->N ) ) != 0 ||
+        ( ret = mbedtls_asn1_get_mpi( p, end, &rsa->E ) ) != 0 )
+        return( MBEDTLS_ERR_PK_INVALID_PUBKEY + ret );
+
+    if( *p != end )
+        return( MBEDTLS_ERR_PK_INVALID_PUBKEY +
+                MBEDTLS_ERR_ASN1_LENGTH_MISMATCH );
+
+    if( ( ret = mbedtls_rsa_check_pubkey( rsa ) ) != 0 )
+        return( MBEDTLS_ERR_PK_INVALID_PUBKEY );
+
+    rsa->len = mbedtls_mpi_size( &rsa->N );
+
+    return( 0 );
+}
+#endif /* MBEDTLS_RSA_C */
+
+/* Get a PK algorithm identifier
+ *
+ *  AlgorithmIdentifier  ::=  SEQUENCE  {
+ *       algorithm               OBJECT IDENTIFIER,
+ *       parameters              ANY DEFINED BY algorithm OPTIONAL  }
+ */
+static int pk_get_pk_alg( unsigned char **p,
+                          const unsigned char *end,
+                          mbedtls_pk_type_t *pk_alg, mbedtls_asn1_buf *params )
+{
+    int ret;
+    mbedtls_asn1_buf alg_oid;
+
+    memset( params, 0, sizeof(mbedtls_asn1_buf) );
+
+    if( ( ret = mbedtls_asn1_get_alg( p, end, &alg_oid, params ) ) != 0 )
+        return( MBEDTLS_ERR_PK_INVALID_ALG + ret );
+
+    if( mbedtls_oid_get_pk_alg( &alg_oid, pk_alg ) != 0 )
+        return( MBEDTLS_ERR_PK_UNKNOWN_PK_ALG );
+
+    /*
+     * No parameters with RSA (only for EC)
+     */
+    if( *pk_alg == MBEDTLS_PK_RSA &&
+            ( ( params->tag != MBEDTLS_ASN1_NULL && params->tag != 0 ) ||
+                params->len != 0 ) )
+    {
+        return( MBEDTLS_ERR_PK_INVALID_ALG );
+    }
+
+    return( 0 );
+}
+
+/*
+ *  SubjectPublicKeyInfo  ::=  SEQUENCE  {
+ *       algorithm            AlgorithmIdentifier,
+ *       subjectPublicKey     BIT STRING }
+ */
+int mbedtls_pk_parse_subpubkey( unsigned char **p, const unsigned char *end,
+                        mbedtls_pk_context *pk )
+{
+    int ret;
+    size_t len;
+    mbedtls_asn1_buf alg_params;
+    mbedtls_pk_type_t pk_alg = MBEDTLS_PK_NONE;
+    const mbedtls_pk_info_t *pk_info;
+
+    if( ( ret = mbedtls_asn1_get_tag( p, end, &len,
+                    MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ) ) != 0 )
+    {
+        return( MBEDTLS_ERR_PK_KEY_INVALID_FORMAT + ret );
+    }
+
+    end = *p + len;
+
+    if( ( ret = pk_get_pk_alg( p, end, &pk_alg, &alg_params ) ) != 0 )
+        return( ret );
+
+    if( ( ret = mbedtls_asn1_get_bitstring_null( p, end, &len ) ) != 0 )
+        return( MBEDTLS_ERR_PK_INVALID_PUBKEY + ret );
+
+    if( *p + len != end )
+        return( MBEDTLS_ERR_PK_INVALID_PUBKEY +
+                MBEDTLS_ERR_ASN1_LENGTH_MISMATCH );
+
+    if( ( pk_info = mbedtls_pk_info_from_type( pk_alg ) ) == NULL )
+        return( MBEDTLS_ERR_PK_UNKNOWN_PK_ALG );
+
+    if( ( ret = mbedtls_pk_setup( pk, pk_info ) ) != 0 )
+        return( ret );
+
+#if defined(MBEDTLS_RSA_C)
+    if( pk_alg == MBEDTLS_PK_RSA )
+    {
+        ret = pk_get_rsapubkey( p, end, mbedtls_pk_rsa( *pk ) );
+    } else
+#endif /* MBEDTLS_RSA_C */
+#if defined(MBEDTLS_ECP_C)
+    if( pk_alg == MBEDTLS_PK_ECKEY_DH || pk_alg == MBEDTLS_PK_ECKEY )
+    {
+        ret = pk_use_ecparams( &alg_params, &mbedtls_pk_ec( *pk )->grp );
+        if( ret == 0 )
+            ret = pk_get_ecpubkey( p, end, mbedtls_pk_ec( *pk ) );
+    } else
+#endif /* MBEDTLS_ECP_C */
+        ret = MBEDTLS_ERR_PK_UNKNOWN_PK_ALG;
+
+    if( ret == 0 && *p != end )
+        ret = MBEDTLS_ERR_PK_INVALID_PUBKEY
+              MBEDTLS_ERR_ASN1_LENGTH_MISMATCH;
+
+    if( ret != 0 )
+        mbedtls_pk_free( pk );
+
+    return( ret );
+}
+
+#if defined(MBEDTLS_RSA_C)
+/*
+ * Parse a PKCS#1 encoded private RSA key
+ */
+static int pk_parse_key_pkcs1_der( mbedtls_rsa_context *rsa,
+                                   const unsigned char *key,
+                                   size_t keylen )
+{
+    int ret;
+    size_t len;
+    unsigned char *p, *end;
+
+    p = (unsigned char *) key;
+    end = p + keylen;
+
+    /*
+     * This function parses the RSAPrivateKey (PKCS#1)
+     *
+     *  RSAPrivateKey ::= SEQUENCE {
+     *      version           Version,
+     *      modulus           INTEGER,  -- n
+     *      publicExponent    INTEGER,  -- e
+     *      privateExponent   INTEGER,  -- d
+     *      prime1            INTEGER,  -- p
+     *      prime2            INTEGER,  -- q
+     *      exponent1         INTEGER,  -- d mod (p-1)
+     *      exponent2         INTEGER,  -- d mod (q-1)
+     *      coefficient       INTEGER,  -- (inverse of q) mod p
+     *      otherPrimeInfos   OtherPrimeInfos OPTIONAL
+     *  }
+     */
+    if( ( ret = mbedtls_asn1_get_tag( &p, end, &len,
+            MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ) ) != 0 )
+    {
+        return( MBEDTLS_ERR_PK_KEY_INVALID_FORMAT + ret );
+    }
+
+    end = p + len;
+
+    if( ( ret = mbedtls_asn1_get_int( &p, end, &rsa->ver ) ) != 0 )
+    {
+        return( MBEDTLS_ERR_PK_KEY_INVALID_FORMAT + ret );
+    }
+
+    if( rsa->ver != 0 )
+    {
+        return( MBEDTLS_ERR_PK_KEY_INVALID_VERSION );
+    }
+
+    if( ( ret = mbedtls_asn1_get_mpi( &p, end, &rsa->N  ) ) != 0 ||
+        ( ret = mbedtls_asn1_get_mpi( &p, end, &rsa->E  ) ) != 0 ||
+        ( ret = mbedtls_asn1_get_mpi( &p, end, &rsa->D  ) ) != 0 ||
+        ( ret = mbedtls_asn1_get_mpi( &p, end, &rsa->P  ) ) != 0 ||
+        ( ret = mbedtls_asn1_get_mpi( &p, end, &rsa->Q  ) ) != 0 ||
+        ( ret = mbedtls_asn1_get_mpi( &p, end, &rsa->DP ) ) != 0 ||
+        ( ret = mbedtls_asn1_get_mpi( &p, end, &rsa->DQ ) ) != 0 ||
+        ( ret = mbedtls_asn1_get_mpi( &p, end, &rsa->QP ) ) != 0 )
+    {
+        mbedtls_rsa_free( rsa );
+        return( MBEDTLS_ERR_PK_KEY_INVALID_FORMAT + ret );
+    }
+
+    rsa->len = mbedtls_mpi_size( &rsa->N );
+
+    if( p != end )
+    {
+        mbedtls_rsa_free( rsa );
+        return( MBEDTLS_ERR_PK_KEY_INVALID_FORMAT +
+                MBEDTLS_ERR_ASN1_LENGTH_MISMATCH );
+    }
+
+    if( ( ret = mbedtls_rsa_check_privkey( rsa ) ) != 0 )
+    {
+        mbedtls_rsa_free( rsa );
+        return( ret );
+    }
+
+    return( 0 );
+}
+#endif /* MBEDTLS_RSA_C */
+
+#if defined(MBEDTLS_ECP_C)
+/*
+ * Parse a SEC1 encoded private EC key
+ */
+static int pk_parse_key_sec1_der( mbedtls_ecp_keypair *eck,
+                                  const unsigned char *key,
+                                  size_t keylen )
+{
+    int ret;
+    int version, pubkey_done;
+    size_t len;
+    mbedtls_asn1_buf params;
+    unsigned char *p = (unsigned char *) key;
+    unsigned char *end = p + keylen;
+    unsigned char *end2;
+
+    /*
+     * RFC 5915, or SEC1 Appendix C.4
+     *
+     * ECPrivateKey ::= SEQUENCE {
+     *      version        INTEGER { ecPrivkeyVer1(1) } (ecPrivkeyVer1),
+     *      privateKey     OCTET STRING,
+     *      parameters [0] ECParameters {{ NamedCurve }} OPTIONAL,
+     *      publicKey  [1] BIT STRING OPTIONAL
+     *    }
+     */
+    if( ( ret = mbedtls_asn1_get_tag( &p, end, &len,
+            MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ) ) != 0 )
+    {
+        return( MBEDTLS_ERR_PK_KEY_INVALID_FORMAT + ret );
+    }
+
+    end = p + len;
+
+    if( ( ret = mbedtls_asn1_get_int( &p, end, &version ) ) != 0 )
+        return( MBEDTLS_ERR_PK_KEY_INVALID_FORMAT + ret );
+
+    if( version != 1 )
+        return( MBEDTLS_ERR_PK_KEY_INVALID_VERSION );
+
+    if( ( ret = mbedtls_asn1_get_tag( &p, end, &len, MBEDTLS_ASN1_OCTET_STRING ) ) != 0 )
+        return( MBEDTLS_ERR_PK_KEY_INVALID_FORMAT + ret );
+
+    if( ( ret = mbedtls_mpi_read_binary( &eck->d, p, len ) ) != 0 )
+    {
+        mbedtls_ecp_keypair_free( eck );
+        return( MBEDTLS_ERR_PK_KEY_INVALID_FORMAT + ret );
+    }
+
+    p += len;
+
+    pubkey_done = 0;
+    if( p != end )
+    {
+        /*
+         * Is 'parameters' present?
+         */
+        if( ( ret = mbedtls_asn1_get_tag( &p, end, &len,
+                        MBEDTLS_ASN1_CONTEXT_SPECIFIC | MBEDTLS_ASN1_CONSTRUCTED | 0 ) ) == 0 )
+        {
+            if( ( ret = pk_get_ecparams( &p, p + len, &params) ) != 0 ||
+                ( ret = pk_use_ecparams( &params, &eck->grp )  ) != 0 )
+            {
+                mbedtls_ecp_keypair_free( eck );
+                return( ret );
+            }
+        }
+        else if( ret != MBEDTLS_ERR_ASN1_UNEXPECTED_TAG )
+        {
+            mbedtls_ecp_keypair_free( eck );
+            return( MBEDTLS_ERR_PK_KEY_INVALID_FORMAT + ret );
+        }
+
+        /*
+         * Is 'publickey' present? If not, or if we can't read it (eg because it
+         * is compressed), create it from the private key.
+         */
+        if( ( ret = mbedtls_asn1_get_tag( &p, end, &len,
+                        MBEDTLS_ASN1_CONTEXT_SPECIFIC | MBEDTLS_ASN1_CONSTRUCTED | 1 ) ) == 0 )
+        {
+            end2 = p + len;
+
+            if( ( ret = mbedtls_asn1_get_bitstring_null( &p, end2, &len ) ) != 0 )
+                return( MBEDTLS_ERR_PK_KEY_INVALID_FORMAT + ret );
+
+            if( p + len != end2 )
+                return( MBEDTLS_ERR_PK_KEY_INVALID_FORMAT +
+                        MBEDTLS_ERR_ASN1_LENGTH_MISMATCH );
+
+            if( ( ret = pk_get_ecpubkey( &p, end2, eck ) ) == 0 )
+                pubkey_done = 1;
+            else
+            {
+                /*
+                 * The only acceptable failure mode of pk_get_ecpubkey() above
+                 * is if the point format is not recognized.
+                 */
+                if( ret != MBEDTLS_ERR_ECP_FEATURE_UNAVAILABLE )
+                    return( MBEDTLS_ERR_PK_KEY_INVALID_FORMAT );
+            }
+        }
+        else if( ret != MBEDTLS_ERR_ASN1_UNEXPECTED_TAG )
+        {
+            mbedtls_ecp_keypair_free( eck );
+            return( MBEDTLS_ERR_PK_KEY_INVALID_FORMAT + ret );
+        }
+    }
+
+    if( ! pubkey_done &&
+        ( ret = mbedtls_ecp_mul( &eck->grp, &eck->Q, &eck->d, &eck->grp.G,
+                                                      NULL, NULL ) ) != 0 )
+    {
+        mbedtls_ecp_keypair_free( eck );
+        return( MBEDTLS_ERR_PK_KEY_INVALID_FORMAT + ret );
+    }
+
+    if( ( ret = mbedtls_ecp_check_privkey( &eck->grp, &eck->d ) ) != 0 )
+    {
+        mbedtls_ecp_keypair_free( eck );
+        return( ret );
+    }
+
+    return( 0 );
+}
+#endif /* MBEDTLS_ECP_C */
+
+/*
+ * Parse an unencrypted PKCS#8 encoded private key
+ */
+static int pk_parse_key_pkcs8_unencrypted_der(
+                                    mbedtls_pk_context *pk,
+                                    const unsigned char* key,
+                                    size_t keylen )
+{
+    int ret, version;
+    size_t len;
+    mbedtls_asn1_buf params;
+    unsigned char *p = (unsigned char *) key;
+    unsigned char *end = p + keylen;
+    mbedtls_pk_type_t pk_alg = MBEDTLS_PK_NONE;
+    const mbedtls_pk_info_t *pk_info;
+
+    /*
+     * This function parses the PrivatKeyInfo object (PKCS#8 v1.2 = RFC 5208)
+     *
+     *    PrivateKeyInfo ::= SEQUENCE {
+     *      version                   Version,
+     *      privateKeyAlgorithm       PrivateKeyAlgorithmIdentifier,
+     *      privateKey                PrivateKey,
+     *      attributes           [0]  IMPLICIT Attributes OPTIONAL }
+     *
+     *    Version ::= INTEGER
+     *    PrivateKeyAlgorithmIdentifier ::= AlgorithmIdentifier
+     *    PrivateKey ::= OCTET STRING
+     *
+     *  The PrivateKey OCTET STRING is a SEC1 ECPrivateKey
+     */
+
+    if( ( ret = mbedtls_asn1_get_tag( &p, end, &len,
+            MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ) ) != 0 )
+    {
+        return( MBEDTLS_ERR_PK_KEY_INVALID_FORMAT + ret );
+    }
+
+    end = p + len;
+
+    if( ( ret = mbedtls_asn1_get_int( &p, end, &version ) ) != 0 )
+        return( MBEDTLS_ERR_PK_KEY_INVALID_FORMAT + ret );
+
+    if( version != 0 )
+        return( MBEDTLS_ERR_PK_KEY_INVALID_VERSION + ret );
+
+    if( ( ret = pk_get_pk_alg( &p, end, &pk_alg, &params ) ) != 0 )
+        return( MBEDTLS_ERR_PK_KEY_INVALID_FORMAT + ret );
+
+    if( ( ret = mbedtls_asn1_get_tag( &p, end, &len, MBEDTLS_ASN1_OCTET_STRING ) ) != 0 )
+        return( MBEDTLS_ERR_PK_KEY_INVALID_FORMAT + ret );
+
+    if( len < 1 )
+        return( MBEDTLS_ERR_PK_KEY_INVALID_FORMAT +
+                MBEDTLS_ERR_ASN1_OUT_OF_DATA );
+
+    if( ( pk_info = mbedtls_pk_info_from_type( pk_alg ) ) == NULL )
+        return( MBEDTLS_ERR_PK_UNKNOWN_PK_ALG );
+
+    if( ( ret = mbedtls_pk_setup( pk, pk_info ) ) != 0 )
+        return( ret );
+
+#if defined(MBEDTLS_RSA_C)
+    if( pk_alg == MBEDTLS_PK_RSA )
+    {
+        if( ( ret = pk_parse_key_pkcs1_der( mbedtls_pk_rsa( *pk ), p, len ) ) != 0 )
+        {
+            mbedtls_pk_free( pk );
+            return( ret );
+        }
+    } else
+#endif /* MBEDTLS_RSA_C */
+#if defined(MBEDTLS_ECP_C)
+    if( pk_alg == MBEDTLS_PK_ECKEY || pk_alg == MBEDTLS_PK_ECKEY_DH )
+    {
+        if( ( ret = pk_use_ecparams( &params, &mbedtls_pk_ec( *pk )->grp ) ) != 0 ||
+            ( ret = pk_parse_key_sec1_der( mbedtls_pk_ec( *pk ), p, len )  ) != 0 )
+        {
+            mbedtls_pk_free( pk );
+            return( ret );
+        }
+    } else
+#endif /* MBEDTLS_ECP_C */
+        return( MBEDTLS_ERR_PK_UNKNOWN_PK_ALG );
+
+    return( 0 );
+}
+
+/*
+ * Parse an encrypted PKCS#8 encoded private key
+ */
+#if defined(MBEDTLS_PKCS12_C) || defined(MBEDTLS_PKCS5_C)
+static int pk_parse_key_pkcs8_encrypted_der(
+                                    mbedtls_pk_context *pk,
+                                    const unsigned char *key, size_t keylen,
+                                    const unsigned char *pwd, size_t pwdlen )
+{
+    int ret, decrypted = 0;
+    size_t len;
+    unsigned char buf[2048];
+    unsigned char *p, *end;
+    mbedtls_asn1_buf pbe_alg_oid, pbe_params;
+#if defined(MBEDTLS_PKCS12_C)
+    mbedtls_cipher_type_t cipher_alg;
+    mbedtls_md_type_t md_alg;
+#endif
+
+    memset( buf, 0, sizeof( buf ) );
+
+    p = (unsigned char *) key;
+    end = p + keylen;
+
+    if( pwdlen == 0 )
+        return( MBEDTLS_ERR_PK_PASSWORD_REQUIRED );
+
+    /*
+     * This function parses the EncryptedPrivatKeyInfo object (PKCS#8)
+     *
+     *  EncryptedPrivateKeyInfo ::= SEQUENCE {
+     *    encryptionAlgorithm  EncryptionAlgorithmIdentifier,
+     *    encryptedData        EncryptedData
+     *  }
+     *
+     *  EncryptionAlgorithmIdentifier ::= AlgorithmIdentifier
+     *
+     *  EncryptedData ::= OCTET STRING
+     *
+     *  The EncryptedData OCTET STRING is a PKCS#8 PrivateKeyInfo
+     */
+    if( ( ret = mbedtls_asn1_get_tag( &p, end, &len,
+            MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ) ) != 0 )
+    {
+        return( MBEDTLS_ERR_PK_KEY_INVALID_FORMAT + ret );
+    }
+
+    end = p + len;
+
+    if( ( ret = mbedtls_asn1_get_alg( &p, end, &pbe_alg_oid, &pbe_params ) ) != 0 )
+        return( MBEDTLS_ERR_PK_KEY_INVALID_FORMAT + ret );
+
+    if( ( ret = mbedtls_asn1_get_tag( &p, end, &len, MBEDTLS_ASN1_OCTET_STRING ) ) != 0 )
+        return( MBEDTLS_ERR_PK_KEY_INVALID_FORMAT + ret );
+
+    if( len > sizeof( buf ) )
+        return( MBEDTLS_ERR_PK_BAD_INPUT_DATA );
+
+    /*
+     * Decrypt EncryptedData with appropriate PDE
+     */
+#if defined(MBEDTLS_PKCS12_C)
+    if( mbedtls_oid_get_pkcs12_pbe_alg( &pbe_alg_oid, &md_alg, &cipher_alg ) == 0 )
+    {
+        if( ( ret = mbedtls_pkcs12_pbe( &pbe_params, MBEDTLS_PKCS12_PBE_DECRYPT,
+                                cipher_alg, md_alg,
+                                pwd, pwdlen, p, len, buf ) ) != 0 )
+        {
+            if( ret == MBEDTLS_ERR_PKCS12_PASSWORD_MISMATCH )
+                return( MBEDTLS_ERR_PK_PASSWORD_MISMATCH );
+
+            return( ret );
+        }
+
+        decrypted = 1;
+    }
+    else if( MBEDTLS_OID_CMP( MBEDTLS_OID_PKCS12_PBE_SHA1_RC4_128, &pbe_alg_oid ) == 0 )
+    {
+        if( ( ret = mbedtls_pkcs12_pbe_sha1_rc4_128( &pbe_params,
+                                             MBEDTLS_PKCS12_PBE_DECRYPT,
+                                             pwd, pwdlen,
+                                             p, len, buf ) ) != 0 )
+        {
+            return( ret );
+        }
+
+        // Best guess for password mismatch when using RC4. If first tag is
+        // not MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE
+        //
+        if( *buf != ( MBEDTLS_ASN1_CONSTRUCTED | MBEDTLS_ASN1_SEQUENCE ) )
+            return( MBEDTLS_ERR_PK_PASSWORD_MISMATCH );
+
+        decrypted = 1;
+    }
+    else
+#endif /* MBEDTLS_PKCS12_C */
+#if defined(MBEDTLS_PKCS5_C)
+    if( MBEDTLS_OID_CMP( MBEDTLS_OID_PKCS5_PBES2, &pbe_alg_oid ) == 0 )
+    {
+        if( ( ret = mbedtls_pkcs5_pbes2( &pbe_params, MBEDTLS_PKCS5_DECRYPT, pwd, pwdlen,
+                                  p, len, buf ) ) != 0 )
+        {
+            if( ret == MBEDTLS_ERR_PKCS5_PASSWORD_MISMATCH )
+                return( MBEDTLS_ERR_PK_PASSWORD_MISMATCH );
+
+            return( ret );
+        }
+
+        decrypted = 1;
+    }
+    else
+#endif /* MBEDTLS_PKCS5_C */
+    {
+        ((void) pwd);
+    }
+
+    if( decrypted == 0 )
+        return( MBEDTLS_ERR_PK_FEATURE_UNAVAILABLE );
+
+    return( pk_parse_key_pkcs8_unencrypted_der( pk, buf, len ) );
+}
+#endif /* MBEDTLS_PKCS12_C || MBEDTLS_PKCS5_C */
+
+/*
+ * Parse a private key
+ */
+int mbedtls_pk_parse_key( mbedtls_pk_context *pk,
+                  const unsigned char *key, size_t keylen,
+                  const unsigned char *pwd, size_t pwdlen )
+{
+    int ret;
+    const mbedtls_pk_info_t *pk_info;
+
+#if defined(MBEDTLS_PEM_PARSE_C)
+    size_t len;
+    mbedtls_pem_context pem;
+
+    mbedtls_pem_init( &pem );
+
+#if defined(MBEDTLS_RSA_C)
+    /* Avoid calling mbedtls_pem_read_buffer() on non-null-terminated string */
+    if( keylen == 0 || key[keylen - 1] != '\0' )
+        ret = MBEDTLS_ERR_PEM_NO_HEADER_FOOTER_PRESENT;
+    else
+        ret = mbedtls_pem_read_buffer( &pem,
+                               "-----BEGIN RSA PRIVATE KEY-----",
+                               "-----END RSA PRIVATE KEY-----",
+                               key, pwd, pwdlen, &len );
+
+    if( ret == 0 )
+    {
+        if( ( pk_info = mbedtls_pk_info_from_type( MBEDTLS_PK_RSA ) ) == NULL )
+            return( MBEDTLS_ERR_PK_UNKNOWN_PK_ALG );
+
+        if( ( ret = mbedtls_pk_setup( pk, pk_info                    ) ) != 0 ||
+            ( ret = pk_parse_key_pkcs1_der( mbedtls_pk_rsa( *pk ),
+                                            pem.buf, pem.buflen ) ) != 0 )
+        {
+            mbedtls_pk_free( pk );
+        }
+
+        mbedtls_pem_free( &pem );
+        return( ret );
+    }
+    else if( ret == MBEDTLS_ERR_PEM_PASSWORD_MISMATCH )
+        return( MBEDTLS_ERR_PK_PASSWORD_MISMATCH );
+    else if( ret == MBEDTLS_ERR_PEM_PASSWORD_REQUIRED )
+        return( MBEDTLS_ERR_PK_PASSWORD_REQUIRED );
+    else if( ret != MBEDTLS_ERR_PEM_NO_HEADER_FOOTER_PRESENT )
+        return( ret );
+#endif /* MBEDTLS_RSA_C */
+
+#if defined(MBEDTLS_ECP_C)
+    /* Avoid calling mbedtls_pem_read_buffer() on non-null-terminated string */
+    if( keylen == 0 || key[keylen - 1] != '\0' )
+        ret = MBEDTLS_ERR_PEM_NO_HEADER_FOOTER_PRESENT;
+    else
+        ret = mbedtls_pem_read_buffer( &pem,
+                               "-----BEGIN EC PRIVATE KEY-----",
+                               "-----END EC PRIVATE KEY-----",
+                               key, pwd, pwdlen, &len );
+    if( ret == 0 )
+    {
+        if( ( pk_info = mbedtls_pk_info_from_type( MBEDTLS_PK_ECKEY ) ) == NULL )
+            return( MBEDTLS_ERR_PK_UNKNOWN_PK_ALG );
+
+        if( ( ret = mbedtls_pk_setup( pk, pk_info                   ) ) != 0 ||
+            ( ret = pk_parse_key_sec1_der( mbedtls_pk_ec( *pk ),
+                                           pem.buf, pem.buflen ) ) != 0 )
+        {
+            mbedtls_pk_free( pk );
+        }
+
+        mbedtls_pem_free( &pem );
+        return( ret );
+    }
+    else if( ret == MBEDTLS_ERR_PEM_PASSWORD_MISMATCH )
+        return( MBEDTLS_ERR_PK_PASSWORD_MISMATCH );
+    else if( ret == MBEDTLS_ERR_PEM_PASSWORD_REQUIRED )
+        return( MBEDTLS_ERR_PK_PASSWORD_REQUIRED );
+    else if( ret != MBEDTLS_ERR_PEM_NO_HEADER_FOOTER_PRESENT )
+        return( ret );
+#endif /* MBEDTLS_ECP_C */
+
+    /* Avoid calling mbedtls_pem_read_buffer() on non-null-terminated string */
+    if( keylen == 0 || key[keylen - 1] != '\0' )
+        ret = MBEDTLS_ERR_PEM_NO_HEADER_FOOTER_PRESENT;
+    else
+        ret = mbedtls_pem_read_buffer( &pem,
+                               "-----BEGIN PRIVATE KEY-----",
+                               "-----END PRIVATE KEY-----",
+                               key, NULL, 0, &len );
+    if( ret == 0 )
+    {
+        if( ( ret = pk_parse_key_pkcs8_unencrypted_der( pk,
+                                                pem.buf, pem.buflen ) ) != 0 )
+        {
+            mbedtls_pk_free( pk );
+        }
+
+        mbedtls_pem_free( &pem );
+        return( ret );
+    }
+    else if( ret != MBEDTLS_ERR_PEM_NO_HEADER_FOOTER_PRESENT )
+        return( ret );
+
+#if defined(MBEDTLS_PKCS12_C) || defined(MBEDTLS_PKCS5_C)
+    /* Avoid calling mbedtls_pem_read_buffer() on non-null-terminated string */
+    if( keylen == 0 || key[keylen - 1] != '\0' )
+        ret = MBEDTLS_ERR_PEM_NO_HEADER_FOOTER_PRESENT;
+    else
+        ret = mbedtls_pem_read_buffer( &pem,
+                               "-----BEGIN ENCRYPTED PRIVATE KEY-----",
+                               "-----END ENCRYPTED PRIVATE KEY-----",
+                               key, NULL, 0, &len );
+    if( ret == 0 )
+    {
+        if( ( ret = pk_parse_key_pkcs8_encrypted_der( pk,
+                                                      pem.buf, pem.buflen,
+                                                      pwd, pwdlen ) ) != 0 )
+        {
+            mbedtls_pk_free( pk );
+        }
+
+        mbedtls_pem_free( &pem );
+        return( ret );
+    }
+    else if( ret != MBEDTLS_ERR_PEM_NO_HEADER_FOOTER_PRESENT )
+        return( ret );
+#endif /* MBEDTLS_PKCS12_C || MBEDTLS_PKCS5_C */
+#else
+    ((void) ret);
+    ((void) pwd);
+    ((void) pwdlen);
+#endif /* MBEDTLS_PEM_PARSE_C */
+
+    /*
+    * At this point we only know it's not a PEM formatted key. Could be any
+    * of the known DER encoded private key formats
+    *
+    * We try the different DER format parsers to see if one passes without
+    * error
+    */
+#if defined(MBEDTLS_PKCS12_C) || defined(MBEDTLS_PKCS5_C)
+    if( ( ret = pk_parse_key_pkcs8_encrypted_der( pk, key, keylen,
+                                                  pwd, pwdlen ) ) == 0 )
+    {
+        return( 0 );
+    }
+
+    mbedtls_pk_free( pk );
+
+    if( ret == MBEDTLS_ERR_PK_PASSWORD_MISMATCH )
+    {
+        return( ret );
+    }
+#endif /* MBEDTLS_PKCS12_C || MBEDTLS_PKCS5_C */
+
+    if( ( ret = pk_parse_key_pkcs8_unencrypted_der( pk, key, keylen ) ) == 0 )
+        return( 0 );
+
+    mbedtls_pk_free( pk );
+
+#if defined(MBEDTLS_RSA_C)
+    if( ( pk_info = mbedtls_pk_info_from_type( MBEDTLS_PK_RSA ) ) == NULL )
+        return( MBEDTLS_ERR_PK_UNKNOWN_PK_ALG );
+
+    if( ( ret = mbedtls_pk_setup( pk, pk_info                           ) ) != 0 ||
+        ( ret = pk_parse_key_pkcs1_der( mbedtls_pk_rsa( *pk ), key, keylen ) ) == 0 )
+    {
+        return( 0 );
+    }
+
+    mbedtls_pk_free( pk );
+#endif /* MBEDTLS_RSA_C */
+
+#if defined(MBEDTLS_ECP_C)
+    if( ( pk_info = mbedtls_pk_info_from_type( MBEDTLS_PK_ECKEY ) ) == NULL )
+        return( MBEDTLS_ERR_PK_UNKNOWN_PK_ALG );
+
+    if( ( ret = mbedtls_pk_setup( pk, pk_info                         ) ) != 0 ||
+        ( ret = pk_parse_key_sec1_der( mbedtls_pk_ec( *pk ), key, keylen ) ) == 0 )
+    {
+        return( 0 );
+    }
+
+    mbedtls_pk_free( pk );
+#endif /* MBEDTLS_ECP_C */
+
+    return( MBEDTLS_ERR_PK_KEY_INVALID_FORMAT );
+}
+
+/*
+ * Parse a public key
+ */
+int mbedtls_pk_parse_public_key( mbedtls_pk_context *ctx,
+                         const unsigned char *key, size_t keylen )
+{
+    int ret;
+    unsigned char *p;
+#if defined(MBEDTLS_PEM_PARSE_C)
+    size_t len;
+    mbedtls_pem_context pem;
+
+    mbedtls_pem_init( &pem );
+
+    /* Avoid calling mbedtls_pem_read_buffer() on non-null-terminated string */
+    if( keylen == 0 || key[keylen - 1] != '\0' )
+        ret = MBEDTLS_ERR_PEM_NO_HEADER_FOOTER_PRESENT;
+    else
+        ret = mbedtls_pem_read_buffer( &pem,
+                "-----BEGIN PUBLIC KEY-----",
+                "-----END PUBLIC KEY-----",
+                key, NULL, 0, &len );
+
+    if( ret == 0 )
+    {
+        /*
+         * Was PEM encoded
+         */
+        key = pem.buf;
+        keylen = pem.buflen;
+    }
+    else if( ret != MBEDTLS_ERR_PEM_NO_HEADER_FOOTER_PRESENT )
+    {
+        mbedtls_pem_free( &pem );
+        return( ret );
+    }
+#endif /* MBEDTLS_PEM_PARSE_C */
+    p = (unsigned char *) key;
+
+    ret = mbedtls_pk_parse_subpubkey( &p, p + keylen, ctx );
+
+#if defined(MBEDTLS_PEM_PARSE_C)
+    mbedtls_pem_free( &pem );
+#endif
+
+    return( ret );
+}
+
+#endif /* MBEDTLS_PK_PARSE_C */