|  | /** | 
|  | * \file rsa.h | 
|  | * | 
|  | * \brief This file provides an API for the RSA public-key cryptosystem. | 
|  | * | 
|  | * The RSA public-key cryptosystem is defined in <em>Public-Key | 
|  | * Cryptography Standards (PKCS) #1 v1.5: RSA Encryption</em> | 
|  | * and <em>Public-Key Cryptography Standards (PKCS) #1 v2.1: | 
|  | * RSA Cryptography Specifications</em>. | 
|  | * | 
|  | */ | 
|  | /* | 
|  | *  Copyright The Mbed TLS Contributors | 
|  | *  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. | 
|  | */ | 
|  | #ifndef MBEDTLS_RSA_H | 
|  | #define MBEDTLS_RSA_H | 
|  |  | 
|  | #if !defined(MBEDTLS_CONFIG_FILE) | 
|  | #include "mbedtls/config.h" | 
|  | #else | 
|  | #include MBEDTLS_CONFIG_FILE | 
|  | #endif | 
|  |  | 
|  | #include "mbedtls/bignum.h" | 
|  | #include "mbedtls/md.h" | 
|  |  | 
|  | #if defined(MBEDTLS_THREADING_C) | 
|  | #include "mbedtls/threading.h" | 
|  | #endif | 
|  |  | 
|  | /* | 
|  | * RSA Error codes | 
|  | */ | 
|  | /** Bad input parameters to function. */ | 
|  | #define MBEDTLS_ERR_RSA_BAD_INPUT_DATA                    -0x4080 | 
|  | /** Input data contains invalid padding and is rejected. */ | 
|  | #define MBEDTLS_ERR_RSA_INVALID_PADDING                   -0x4100 | 
|  | /** Something failed during generation of a key. */ | 
|  | #define MBEDTLS_ERR_RSA_KEY_GEN_FAILED                    -0x4180 | 
|  | /** Key failed to pass the validity check of the library. */ | 
|  | #define MBEDTLS_ERR_RSA_KEY_CHECK_FAILED                  -0x4200 | 
|  | /** The public key operation failed. */ | 
|  | #define MBEDTLS_ERR_RSA_PUBLIC_FAILED                     -0x4280 | 
|  | /** The private key operation failed. */ | 
|  | #define MBEDTLS_ERR_RSA_PRIVATE_FAILED                    -0x4300 | 
|  | /** The PKCS#1 verification failed. */ | 
|  | #define MBEDTLS_ERR_RSA_VERIFY_FAILED                     -0x4380 | 
|  | /** The output buffer for decryption is not large enough. */ | 
|  | #define MBEDTLS_ERR_RSA_OUTPUT_TOO_LARGE                  -0x4400 | 
|  | /** The random generator failed to generate non-zeros. */ | 
|  | #define MBEDTLS_ERR_RSA_RNG_FAILED                        -0x4480 | 
|  |  | 
|  | /* MBEDTLS_ERR_RSA_UNSUPPORTED_OPERATION is deprecated and should not be used. | 
|  | */ | 
|  | /** The implementation does not offer the requested operation, for example, because of security violations or lack of functionality. */ | 
|  | #define MBEDTLS_ERR_RSA_UNSUPPORTED_OPERATION             -0x4500 | 
|  |  | 
|  | /* MBEDTLS_ERR_RSA_HW_ACCEL_FAILED is deprecated and should not be used. */ | 
|  | /** RSA hardware accelerator failed. */ | 
|  | #define MBEDTLS_ERR_RSA_HW_ACCEL_FAILED                   -0x4580 | 
|  |  | 
|  | /* | 
|  | * RSA constants | 
|  | */ | 
|  | #define MBEDTLS_RSA_PUBLIC      0 /**< Request private key operation. */ | 
|  | #define MBEDTLS_RSA_PRIVATE     1 /**< Request public key operation. */ | 
|  |  | 
|  | #define MBEDTLS_RSA_PKCS_V15    0 /**< Use PKCS#1 v1.5 encoding. */ | 
|  | #define MBEDTLS_RSA_PKCS_V21    1 /**< Use PKCS#1 v2.1 encoding. */ | 
|  |  | 
|  | #define MBEDTLS_RSA_SIGN        1 /**< Identifier for RSA signature operations. */ | 
|  | #define MBEDTLS_RSA_CRYPT       2 /**< Identifier for RSA encryption and decryption operations. */ | 
|  |  | 
|  | #define MBEDTLS_RSA_SALT_LEN_ANY    -1 | 
|  |  | 
|  | /* | 
|  | * The above constants may be used even if the RSA module is compile out, | 
|  | * eg for alternative (PKCS#11) RSA implementations in the PK layers. | 
|  | */ | 
|  |  | 
|  | #ifdef __cplusplus | 
|  | extern "C" { | 
|  | #endif | 
|  |  | 
|  | #if !defined(MBEDTLS_RSA_ALT) | 
|  | // Regular implementation | 
|  | // | 
|  |  | 
|  | /** | 
|  | * \brief   The RSA context structure. | 
|  | * | 
|  | * \note    Direct manipulation of the members of this structure | 
|  | *          is deprecated. All manipulation should instead be done through | 
|  | *          the public interface functions. | 
|  | */ | 
|  | typedef struct mbedtls_rsa_context { | 
|  | int ver;                    /*!<  Reserved for internal purposes. | 
|  | *    Do not set this field in application | 
|  | *    code. Its meaning might change without | 
|  | *    notice. */ | 
|  | size_t len;                 /*!<  The size of \p N in Bytes. */ | 
|  |  | 
|  | mbedtls_mpi N;              /*!<  The public modulus. */ | 
|  | mbedtls_mpi E;              /*!<  The public exponent. */ | 
|  |  | 
|  | mbedtls_mpi D;              /*!<  The private exponent. */ | 
|  | mbedtls_mpi P;              /*!<  The first prime factor. */ | 
|  | mbedtls_mpi Q;              /*!<  The second prime factor. */ | 
|  |  | 
|  | mbedtls_mpi DP;             /*!<  <code>D % (P - 1)</code>. */ | 
|  | mbedtls_mpi DQ;             /*!<  <code>D % (Q - 1)</code>. */ | 
|  | mbedtls_mpi QP;             /*!<  <code>1 / (Q % P)</code>. */ | 
|  |  | 
|  | mbedtls_mpi RN;             /*!<  cached <code>R^2 mod N</code>. */ | 
|  |  | 
|  | mbedtls_mpi RP;             /*!<  cached <code>R^2 mod P</code>. */ | 
|  | mbedtls_mpi RQ;             /*!<  cached <code>R^2 mod Q</code>. */ | 
|  |  | 
|  | mbedtls_mpi Vi;             /*!<  The cached blinding value. */ | 
|  | mbedtls_mpi Vf;             /*!<  The cached un-blinding value. */ | 
|  |  | 
|  | int padding;                /*!< Selects padding mode: | 
|  | #MBEDTLS_RSA_PKCS_V15 for 1.5 padding and | 
|  | #MBEDTLS_RSA_PKCS_V21 for OAEP or PSS. */ | 
|  | int hash_id;                /*!< Hash identifier of mbedtls_md_type_t type, | 
|  | as specified in md.h for use in the MGF | 
|  | mask generating function used in the | 
|  | EME-OAEP and EMSA-PSS encodings. */ | 
|  | #if defined(MBEDTLS_THREADING_C) | 
|  | /* Invariant: the mutex is initialized iff ver != 0. */ | 
|  | mbedtls_threading_mutex_t mutex;    /*!<  Thread-safety mutex. */ | 
|  | #endif | 
|  | } | 
|  | mbedtls_rsa_context; | 
|  |  | 
|  | #else  /* MBEDTLS_RSA_ALT */ | 
|  | #include "rsa_alt.h" | 
|  | #endif /* MBEDTLS_RSA_ALT */ | 
|  |  | 
|  | /** | 
|  | * \brief          This function initializes an RSA context. | 
|  | * | 
|  | * \note           Set padding to #MBEDTLS_RSA_PKCS_V21 for the RSAES-OAEP | 
|  | *                 encryption scheme and the RSASSA-PSS signature scheme. | 
|  | * | 
|  | * \note           The \p hash_id parameter is ignored when using | 
|  | *                 #MBEDTLS_RSA_PKCS_V15 padding. | 
|  | * | 
|  | * \note           The choice of padding mode is strictly enforced for private key | 
|  | *                 operations, since there might be security concerns in | 
|  | *                 mixing padding modes. For public key operations it is | 
|  | *                 a default value, which can be overridden by calling specific | 
|  | *                 \c rsa_rsaes_xxx or \c rsa_rsassa_xxx functions. | 
|  | * | 
|  | * \note           The hash selected in \p hash_id is always used for OEAP | 
|  | *                 encryption. For PSS signatures, it is always used for | 
|  | *                 making signatures, but can be overridden for verifying them. | 
|  | *                 If set to #MBEDTLS_MD_NONE, it is always overridden. | 
|  | * | 
|  | * \param ctx      The RSA context to initialize. This must not be \c NULL. | 
|  | * \param padding  The padding mode to use. This must be either | 
|  | *                 #MBEDTLS_RSA_PKCS_V15 or #MBEDTLS_RSA_PKCS_V21. | 
|  | * \param hash_id  The hash identifier of ::mbedtls_md_type_t type, if | 
|  | *                 \p padding is #MBEDTLS_RSA_PKCS_V21. It is unused | 
|  | *                 otherwise. | 
|  | */ | 
|  | void mbedtls_rsa_init(mbedtls_rsa_context *ctx, | 
|  | int padding, | 
|  | int hash_id); | 
|  |  | 
|  | /** | 
|  | * \brief          This function imports a set of core parameters into an | 
|  | *                 RSA context. | 
|  | * | 
|  | * \note           This function can be called multiple times for successive | 
|  | *                 imports, if the parameters are not simultaneously present. | 
|  | * | 
|  | *                 Any sequence of calls to this function should be followed | 
|  | *                 by a call to mbedtls_rsa_complete(), which checks and | 
|  | *                 completes the provided information to a ready-for-use | 
|  | *                 public or private RSA key. | 
|  | * | 
|  | * \note           See mbedtls_rsa_complete() for more information on which | 
|  | *                 parameters are necessary to set up a private or public | 
|  | *                 RSA key. | 
|  | * | 
|  | * \note           The imported parameters are copied and need not be preserved | 
|  | *                 for the lifetime of the RSA context being set up. | 
|  | * | 
|  | * \param ctx      The initialized RSA context to store the parameters in. | 
|  | * \param N        The RSA modulus. This may be \c NULL. | 
|  | * \param P        The first prime factor of \p N. This may be \c NULL. | 
|  | * \param Q        The second prime factor of \p N. This may be \c NULL. | 
|  | * \param D        The private exponent. This may be \c NULL. | 
|  | * \param E        The public exponent. This may be \c NULL. | 
|  | * | 
|  | * \return         \c 0 on success. | 
|  | * \return         A non-zero error code on failure. | 
|  | */ | 
|  | int mbedtls_rsa_import(mbedtls_rsa_context *ctx, | 
|  | const mbedtls_mpi *N, | 
|  | const mbedtls_mpi *P, const mbedtls_mpi *Q, | 
|  | const mbedtls_mpi *D, const mbedtls_mpi *E); | 
|  |  | 
|  | /** | 
|  | * \brief          This function imports core RSA parameters, in raw big-endian | 
|  | *                 binary format, into an RSA context. | 
|  | * | 
|  | * \note           This function can be called multiple times for successive | 
|  | *                 imports, if the parameters are not simultaneously present. | 
|  | * | 
|  | *                 Any sequence of calls to this function should be followed | 
|  | *                 by a call to mbedtls_rsa_complete(), which checks and | 
|  | *                 completes the provided information to a ready-for-use | 
|  | *                 public or private RSA key. | 
|  | * | 
|  | * \note           See mbedtls_rsa_complete() for more information on which | 
|  | *                 parameters are necessary to set up a private or public | 
|  | *                 RSA key. | 
|  | * | 
|  | * \note           The imported parameters are copied and need not be preserved | 
|  | *                 for the lifetime of the RSA context being set up. | 
|  | * | 
|  | * \param ctx      The initialized RSA context to store the parameters in. | 
|  | * \param N        The RSA modulus. This may be \c NULL. | 
|  | * \param N_len    The Byte length of \p N; it is ignored if \p N == NULL. | 
|  | * \param P        The first prime factor of \p N. This may be \c NULL. | 
|  | * \param P_len    The Byte length of \p P; it ns ignored if \p P == NULL. | 
|  | * \param Q        The second prime factor of \p N. This may be \c NULL. | 
|  | * \param Q_len    The Byte length of \p Q; it is ignored if \p Q == NULL. | 
|  | * \param D        The private exponent. This may be \c NULL. | 
|  | * \param D_len    The Byte length of \p D; it is ignored if \p D == NULL. | 
|  | * \param E        The public exponent. This may be \c NULL. | 
|  | * \param E_len    The Byte length of \p E; it is ignored if \p E == NULL. | 
|  | * | 
|  | * \return         \c 0 on success. | 
|  | * \return         A non-zero error code on failure. | 
|  | */ | 
|  | int mbedtls_rsa_import_raw(mbedtls_rsa_context *ctx, | 
|  | unsigned char const *N, size_t N_len, | 
|  | unsigned char const *P, size_t P_len, | 
|  | unsigned char const *Q, size_t Q_len, | 
|  | unsigned char const *D, size_t D_len, | 
|  | unsigned char const *E, size_t E_len); | 
|  |  | 
|  | /** | 
|  | * \brief          This function completes an RSA context from | 
|  | *                 a set of imported core parameters. | 
|  | * | 
|  | *                 To setup an RSA public key, precisely \c N and \c E | 
|  | *                 must have been imported. | 
|  | * | 
|  | *                 To setup an RSA private key, sufficient information must | 
|  | *                 be present for the other parameters to be derivable. | 
|  | * | 
|  | *                 The default implementation supports the following: | 
|  | *                 <ul><li>Derive \c P, \c Q from \c N, \c D, \c E.</li> | 
|  | *                 <li>Derive \c N, \c D from \c P, \c Q, \c E.</li></ul> | 
|  | *                 Alternative implementations need not support these. | 
|  | * | 
|  | *                 If this function runs successfully, it guarantees that | 
|  | *                 the RSA context can be used for RSA operations without | 
|  | *                 the risk of failure or crash. | 
|  | * | 
|  | * \warning        This function need not perform consistency checks | 
|  | *                 for the imported parameters. In particular, parameters that | 
|  | *                 are not needed by the implementation might be silently | 
|  | *                 discarded and left unchecked. To check the consistency | 
|  | *                 of the key material, see mbedtls_rsa_check_privkey(). | 
|  | * | 
|  | * \param ctx      The initialized RSA context holding imported parameters. | 
|  | * | 
|  | * \return         \c 0 on success. | 
|  | * \return         #MBEDTLS_ERR_RSA_BAD_INPUT_DATA if the attempted derivations | 
|  | *                 failed. | 
|  | * | 
|  | */ | 
|  | int mbedtls_rsa_complete(mbedtls_rsa_context *ctx); | 
|  |  | 
|  | /** | 
|  | * \brief          This function exports the core parameters of an RSA key. | 
|  | * | 
|  | *                 If this function runs successfully, the non-NULL buffers | 
|  | *                 pointed to by \p N, \p P, \p Q, \p D, and \p E are fully | 
|  | *                 written, with additional unused space filled leading by | 
|  | *                 zero Bytes. | 
|  | * | 
|  | *                 Possible reasons for returning | 
|  | *                 #MBEDTLS_ERR_PLATFORM_FEATURE_UNSUPPORTED:<ul> | 
|  | *                 <li>An alternative RSA implementation is in use, which | 
|  | *                 stores the key externally, and either cannot or should | 
|  | *                 not export it into RAM.</li> | 
|  | *                 <li>A SW or HW implementation might not support a certain | 
|  | *                 deduction. For example, \p P, \p Q from \p N, \p D, | 
|  | *                 and \p E if the former are not part of the | 
|  | *                 implementation.</li></ul> | 
|  | * | 
|  | *                 If the function fails due to an unsupported operation, | 
|  | *                 the RSA context stays intact and remains usable. | 
|  | * | 
|  | * \param ctx      The initialized RSA context. | 
|  | * \param N        The MPI to hold the RSA modulus. | 
|  | *                 This may be \c NULL if this field need not be exported. | 
|  | * \param P        The MPI to hold the first prime factor of \p N. | 
|  | *                 This may be \c NULL if this field need not be exported. | 
|  | * \param Q        The MPI to hold the second prime factor of \p N. | 
|  | *                 This may be \c NULL if this field need not be exported. | 
|  | * \param D        The MPI to hold the private exponent. | 
|  | *                 This may be \c NULL if this field need not be exported. | 
|  | * \param E        The MPI to hold the public exponent. | 
|  | *                 This may be \c NULL if this field need not be exported. | 
|  | * | 
|  | * \return         \c 0 on success. | 
|  | * \return         #MBEDTLS_ERR_PLATFORM_FEATURE_UNSUPPORTED if exporting the | 
|  | *                 requested parameters cannot be done due to missing | 
|  | *                 functionality or because of security policies. | 
|  | * \return         A non-zero return code on any other failure. | 
|  | * | 
|  | */ | 
|  | int mbedtls_rsa_export(const mbedtls_rsa_context *ctx, | 
|  | mbedtls_mpi *N, mbedtls_mpi *P, mbedtls_mpi *Q, | 
|  | mbedtls_mpi *D, mbedtls_mpi *E); | 
|  |  | 
|  | /** | 
|  | * \brief          This function exports core parameters of an RSA key | 
|  | *                 in raw big-endian binary format. | 
|  | * | 
|  | *                 If this function runs successfully, the non-NULL buffers | 
|  | *                 pointed to by \p N, \p P, \p Q, \p D, and \p E are fully | 
|  | *                 written, with additional unused space filled leading by | 
|  | *                 zero Bytes. | 
|  | * | 
|  | *                 Possible reasons for returning | 
|  | *                 #MBEDTLS_ERR_PLATFORM_FEATURE_UNSUPPORTED:<ul> | 
|  | *                 <li>An alternative RSA implementation is in use, which | 
|  | *                 stores the key externally, and either cannot or should | 
|  | *                 not export it into RAM.</li> | 
|  | *                 <li>A SW or HW implementation might not support a certain | 
|  | *                 deduction. For example, \p P, \p Q from \p N, \p D, | 
|  | *                 and \p E if the former are not part of the | 
|  | *                 implementation.</li></ul> | 
|  | *                 If the function fails due to an unsupported operation, | 
|  | *                 the RSA context stays intact and remains usable. | 
|  | * | 
|  | * \note           The length parameters are ignored if the corresponding | 
|  | *                 buffer pointers are NULL. | 
|  | * | 
|  | * \param ctx      The initialized RSA context. | 
|  | * \param N        The Byte array to store the RSA modulus, | 
|  | *                 or \c NULL if this field need not be exported. | 
|  | * \param N_len    The size of the buffer for the modulus. | 
|  | * \param P        The Byte array to hold the first prime factor of \p N, | 
|  | *                 or \c NULL if this field need not be exported. | 
|  | * \param P_len    The size of the buffer for the first prime factor. | 
|  | * \param Q        The Byte array to hold the second prime factor of \p N, | 
|  | *                 or \c NULL if this field need not be exported. | 
|  | * \param Q_len    The size of the buffer for the second prime factor. | 
|  | * \param D        The Byte array to hold the private exponent, | 
|  | *                 or \c NULL if this field need not be exported. | 
|  | * \param D_len    The size of the buffer for the private exponent. | 
|  | * \param E        The Byte array to hold the public exponent, | 
|  | *                 or \c NULL if this field need not be exported. | 
|  | * \param E_len    The size of the buffer for the public exponent. | 
|  | * | 
|  | * \return         \c 0 on success. | 
|  | * \return         #MBEDTLS_ERR_PLATFORM_FEATURE_UNSUPPORTED if exporting the | 
|  | *                 requested parameters cannot be done due to missing | 
|  | *                 functionality or because of security policies. | 
|  | * \return         A non-zero return code on any other failure. | 
|  | */ | 
|  | int mbedtls_rsa_export_raw(const mbedtls_rsa_context *ctx, | 
|  | unsigned char *N, size_t N_len, | 
|  | unsigned char *P, size_t P_len, | 
|  | unsigned char *Q, size_t Q_len, | 
|  | unsigned char *D, size_t D_len, | 
|  | unsigned char *E, size_t E_len); | 
|  |  | 
|  | /** | 
|  | * \brief          This function exports CRT parameters of a private RSA key. | 
|  | * | 
|  | * \note           Alternative RSA implementations not using CRT-parameters | 
|  | *                 internally can implement this function based on | 
|  | *                 mbedtls_rsa_deduce_opt(). | 
|  | * | 
|  | * \param ctx      The initialized RSA context. | 
|  | * \param DP       The MPI to hold \c D modulo `P-1`, | 
|  | *                 or \c NULL if it need not be exported. | 
|  | * \param DQ       The MPI to hold \c D modulo `Q-1`, | 
|  | *                 or \c NULL if it need not be exported. | 
|  | * \param QP       The MPI to hold modular inverse of \c Q modulo \c P, | 
|  | *                 or \c NULL if it need not be exported. | 
|  | * | 
|  | * \return         \c 0 on success. | 
|  | * \return         A non-zero error code on failure. | 
|  | * | 
|  | */ | 
|  | int mbedtls_rsa_export_crt(const mbedtls_rsa_context *ctx, | 
|  | mbedtls_mpi *DP, mbedtls_mpi *DQ, mbedtls_mpi *QP); | 
|  |  | 
|  | /** | 
|  | * \brief          This function sets padding for an already initialized RSA | 
|  | *                 context. See mbedtls_rsa_init() for details. | 
|  | * | 
|  | * \param ctx      The initialized RSA context to be configured. | 
|  | * \param padding  The padding mode to use. This must be either | 
|  | *                 #MBEDTLS_RSA_PKCS_V15 or #MBEDTLS_RSA_PKCS_V21. | 
|  | * \param hash_id  The #MBEDTLS_RSA_PKCS_V21 hash identifier. | 
|  | */ | 
|  | void mbedtls_rsa_set_padding(mbedtls_rsa_context *ctx, int padding, | 
|  | int hash_id); | 
|  |  | 
|  | /** | 
|  | * \brief          This function retrieves the length of RSA modulus in Bytes. | 
|  | * | 
|  | * \param ctx      The initialized RSA context. | 
|  | * | 
|  | * \return         The length of the RSA modulus in Bytes. | 
|  | * | 
|  | */ | 
|  | size_t mbedtls_rsa_get_len(const mbedtls_rsa_context *ctx); | 
|  |  | 
|  | /** | 
|  | * \brief          This function generates an RSA keypair. | 
|  | * | 
|  | * \note           mbedtls_rsa_init() must be called before this function, | 
|  | *                 to set up the RSA context. | 
|  | * | 
|  | * \param ctx      The initialized RSA context used to hold the key. | 
|  | * \param f_rng    The RNG function to be used for key generation. | 
|  | *                 This must not be \c NULL. | 
|  | * \param p_rng    The RNG context to be passed to \p f_rng. | 
|  | *                 This may be \c NULL if \p f_rng doesn't need a context. | 
|  | * \param nbits    The size of the public key in bits. | 
|  | * \param exponent The public exponent to use. For example, \c 65537. | 
|  | *                 This must be odd and greater than \c 1. | 
|  | * | 
|  | * \return         \c 0 on success. | 
|  | * \return         An \c MBEDTLS_ERR_RSA_XXX error code on failure. | 
|  | */ | 
|  | int mbedtls_rsa_gen_key(mbedtls_rsa_context *ctx, | 
|  | int (*f_rng)(void *, unsigned char *, size_t), | 
|  | void *p_rng, | 
|  | unsigned int nbits, int exponent); | 
|  |  | 
|  | /** | 
|  | * \brief          This function checks if a context contains at least an RSA | 
|  | *                 public key. | 
|  | * | 
|  | *                 If the function runs successfully, it is guaranteed that | 
|  | *                 enough information is present to perform an RSA public key | 
|  | *                 operation using mbedtls_rsa_public(). | 
|  | * | 
|  | * \param ctx      The initialized RSA context to check. | 
|  | * | 
|  | * \return         \c 0 on success. | 
|  | * \return         An \c MBEDTLS_ERR_RSA_XXX error code on failure. | 
|  | * | 
|  | */ | 
|  | int mbedtls_rsa_check_pubkey(const mbedtls_rsa_context *ctx); | 
|  |  | 
|  | /** | 
|  | * \brief      This function checks if a context contains an RSA private key | 
|  | *             and perform basic consistency checks. | 
|  | * | 
|  | * \note       The consistency checks performed by this function not only | 
|  | *             ensure that mbedtls_rsa_private() can be called successfully | 
|  | *             on the given context, but that the various parameters are | 
|  | *             mutually consistent with high probability, in the sense that | 
|  | *             mbedtls_rsa_public() and mbedtls_rsa_private() are inverses. | 
|  | * | 
|  | * \warning    This function should catch accidental misconfigurations | 
|  | *             like swapping of parameters, but it cannot establish full | 
|  | *             trust in neither the quality nor the consistency of the key | 
|  | *             material that was used to setup the given RSA context: | 
|  | *             <ul><li>Consistency: Imported parameters that are irrelevant | 
|  | *             for the implementation might be silently dropped. If dropped, | 
|  | *             the current function does not have access to them, | 
|  | *             and therefore cannot check them. See mbedtls_rsa_complete(). | 
|  | *             If you want to check the consistency of the entire | 
|  | *             content of a PKCS1-encoded RSA private key, for example, you | 
|  | *             should use mbedtls_rsa_validate_params() before setting | 
|  | *             up the RSA context. | 
|  | *             Additionally, if the implementation performs empirical checks, | 
|  | *             these checks substantiate but do not guarantee consistency.</li> | 
|  | *             <li>Quality: This function is not expected to perform | 
|  | *             extended quality assessments like checking that the prime | 
|  | *             factors are safe. Additionally, it is the responsibility of the | 
|  | *             user to ensure the trustworthiness of the source of his RSA | 
|  | *             parameters, which goes beyond what is effectively checkable | 
|  | *             by the library.</li></ul> | 
|  | * | 
|  | * \param ctx  The initialized RSA context to check. | 
|  | * | 
|  | * \return     \c 0 on success. | 
|  | * \return     An \c MBEDTLS_ERR_RSA_XXX error code on failure. | 
|  | */ | 
|  | int mbedtls_rsa_check_privkey(const mbedtls_rsa_context *ctx); | 
|  |  | 
|  | /** | 
|  | * \brief          This function checks a public-private RSA key pair. | 
|  | * | 
|  | *                 It checks each of the contexts, and makes sure they match. | 
|  | * | 
|  | * \param pub      The initialized RSA context holding the public key. | 
|  | * \param prv      The initialized RSA context holding the private key. | 
|  | * | 
|  | * \return         \c 0 on success. | 
|  | * \return         An \c MBEDTLS_ERR_RSA_XXX error code on failure. | 
|  | */ | 
|  | int mbedtls_rsa_check_pub_priv(const mbedtls_rsa_context *pub, | 
|  | const mbedtls_rsa_context *prv); | 
|  |  | 
|  | /** | 
|  | * \brief          This function performs an RSA public key operation. | 
|  | * | 
|  | * \param ctx      The initialized RSA context to use. | 
|  | * \param input    The input buffer. This must be a readable buffer | 
|  | *                 of length \c ctx->len Bytes. For example, \c 256 Bytes | 
|  | *                 for an 2048-bit RSA modulus. | 
|  | * \param output   The output buffer. This must be a writable buffer | 
|  | *                 of length \c ctx->len Bytes. For example, \c 256 Bytes | 
|  | *                 for an 2048-bit RSA modulus. | 
|  | * | 
|  | * \note           This function does not handle message padding. | 
|  | * | 
|  | * \note           Make sure to set \p input[0] = 0 or ensure that | 
|  | *                 input is smaller than \c N. | 
|  | * | 
|  | * \return         \c 0 on success. | 
|  | * \return         An \c MBEDTLS_ERR_RSA_XXX error code on failure. | 
|  | */ | 
|  | int mbedtls_rsa_public(mbedtls_rsa_context *ctx, | 
|  | const unsigned char *input, | 
|  | unsigned char *output); | 
|  |  | 
|  | /** | 
|  | * \brief          This function performs an RSA private key operation. | 
|  | * | 
|  | * \note           Blinding is used if and only if a PRNG is provided. | 
|  | * | 
|  | * \note           If blinding is used, both the base of exponentiation | 
|  | *                 and the exponent are blinded, providing protection | 
|  | *                 against some side-channel attacks. | 
|  | * | 
|  | * \warning        It is deprecated and a security risk to not provide | 
|  | *                 a PRNG here and thereby prevent the use of blinding. | 
|  | *                 Future versions of the library may enforce the presence | 
|  | *                 of a PRNG. | 
|  | * | 
|  | * \param ctx      The initialized RSA context to use. | 
|  | * \param f_rng    The RNG function, used for blinding. It is discouraged | 
|  | *                 and deprecated to pass \c NULL here, in which case | 
|  | *                 blinding will be omitted. | 
|  | * \param p_rng    The RNG context to pass to \p f_rng. This may be \c NULL | 
|  | *                 if \p f_rng is \c NULL or if \p f_rng doesn't need a context. | 
|  | * \param input    The input buffer. This must be a readable buffer | 
|  | *                 of length \c ctx->len Bytes. For example, \c 256 Bytes | 
|  | *                 for an 2048-bit RSA modulus. | 
|  | * \param output   The output buffer. This must be a writable buffer | 
|  | *                 of length \c ctx->len Bytes. For example, \c 256 Bytes | 
|  | *                 for an 2048-bit RSA modulus. | 
|  | * | 
|  | * \return         \c 0 on success. | 
|  | * \return         An \c MBEDTLS_ERR_RSA_XXX error code on failure. | 
|  | * | 
|  | */ | 
|  | int mbedtls_rsa_private(mbedtls_rsa_context *ctx, | 
|  | int (*f_rng)(void *, unsigned char *, size_t), | 
|  | void *p_rng, | 
|  | const unsigned char *input, | 
|  | unsigned char *output); | 
|  |  | 
|  | /** | 
|  | * \brief          This function adds the message padding, then performs an RSA | 
|  | *                 operation. | 
|  | * | 
|  | *                 It is the generic wrapper for performing a PKCS#1 encryption | 
|  | *                 operation using the \p mode from the context. | 
|  | * | 
|  | * \deprecated     It is deprecated and discouraged to call this function | 
|  | *                 in #MBEDTLS_RSA_PRIVATE mode. Future versions of the library | 
|  | *                 are likely to remove the \p mode argument and have it | 
|  | *                 implicitly set to #MBEDTLS_RSA_PUBLIC. | 
|  | * | 
|  | * \note           Alternative implementations of RSA need not support | 
|  | *                 mode being set to #MBEDTLS_RSA_PRIVATE and might instead | 
|  | *                 return #MBEDTLS_ERR_PLATFORM_FEATURE_UNSUPPORTED. | 
|  | * | 
|  | * \param ctx      The initialized RSA context to use. | 
|  | * \param f_rng    The RNG to use. It is mandatory for PKCS#1 v2.1 padding | 
|  | *                 encoding, and for PKCS#1 v1.5 padding encoding when used | 
|  | *                 with \p mode set to #MBEDTLS_RSA_PUBLIC. For PKCS#1 v1.5 | 
|  | *                 padding encoding and \p mode set to #MBEDTLS_RSA_PRIVATE, | 
|  | *                 it is used for blinding and should be provided in this | 
|  | *                 case; see mbedtls_rsa_private() for more. | 
|  | * \param p_rng    The RNG context to be passed to \p f_rng. May be | 
|  | *                 \c NULL if \p f_rng is \c NULL or if \p f_rng doesn't | 
|  | *                 need a context argument. | 
|  | * \param mode     The mode of operation. This must be either | 
|  | *                 #MBEDTLS_RSA_PUBLIC or #MBEDTLS_RSA_PRIVATE (deprecated). | 
|  | * \param ilen     The length of the plaintext in Bytes. | 
|  | * \param input    The input data to encrypt. This must be a readable | 
|  | *                 buffer of size \p ilen Bytes. It may be \c NULL if | 
|  | *                 `ilen == 0`. | 
|  | * \param output   The output buffer. This must be a writable buffer | 
|  | *                 of length \c ctx->len Bytes. For example, \c 256 Bytes | 
|  | *                 for an 2048-bit RSA modulus. | 
|  | * | 
|  | * \return         \c 0 on success. | 
|  | * \return         An \c MBEDTLS_ERR_RSA_XXX error code on failure. | 
|  | */ | 
|  | int mbedtls_rsa_pkcs1_encrypt(mbedtls_rsa_context *ctx, | 
|  | int (*f_rng)(void *, unsigned char *, size_t), | 
|  | void *p_rng, | 
|  | int mode, size_t ilen, | 
|  | const unsigned char *input, | 
|  | unsigned char *output); | 
|  |  | 
|  | /** | 
|  | * \brief          This function performs a PKCS#1 v1.5 encryption operation | 
|  | *                 (RSAES-PKCS1-v1_5-ENCRYPT). | 
|  | * | 
|  | * \deprecated     It is deprecated and discouraged to call this function | 
|  | *                 in #MBEDTLS_RSA_PRIVATE mode. Future versions of the library | 
|  | *                 are likely to remove the \p mode argument and have it | 
|  | *                 implicitly set to #MBEDTLS_RSA_PUBLIC. | 
|  | * | 
|  | * \note           Alternative implementations of RSA need not support | 
|  | *                 mode being set to #MBEDTLS_RSA_PRIVATE and might instead | 
|  | *                 return #MBEDTLS_ERR_PLATFORM_FEATURE_UNSUPPORTED. | 
|  | * | 
|  | * \param ctx      The initialized RSA context to use. | 
|  | * \param f_rng    The RNG function to use. It is needed for padding generation | 
|  | *                 if \p mode is #MBEDTLS_RSA_PUBLIC. If \p mode is | 
|  | *                 #MBEDTLS_RSA_PRIVATE (discouraged), it is used for | 
|  | *                 blinding and should be provided; see mbedtls_rsa_private(). | 
|  | * \param p_rng    The RNG context to be passed to \p f_rng. This may | 
|  | *                 be \c NULL if \p f_rng is \c NULL or if \p f_rng | 
|  | *                 doesn't need a context argument. | 
|  | * \param mode     The mode of operation. This must be either | 
|  | *                 #MBEDTLS_RSA_PUBLIC or #MBEDTLS_RSA_PRIVATE (deprecated). | 
|  | * \param ilen     The length of the plaintext in Bytes. | 
|  | * \param input    The input data to encrypt. This must be a readable | 
|  | *                 buffer of size \p ilen Bytes. It may be \c NULL if | 
|  | *                 `ilen == 0`. | 
|  | * \param output   The output buffer. This must be a writable buffer | 
|  | *                 of length \c ctx->len Bytes. For example, \c 256 Bytes | 
|  | *                 for an 2048-bit RSA modulus. | 
|  | * | 
|  | * \return         \c 0 on success. | 
|  | * \return         An \c MBEDTLS_ERR_RSA_XXX error code on failure. | 
|  | */ | 
|  | int mbedtls_rsa_rsaes_pkcs1_v15_encrypt(mbedtls_rsa_context *ctx, | 
|  | int (*f_rng)(void *, unsigned char *, size_t), | 
|  | void *p_rng, | 
|  | int mode, size_t ilen, | 
|  | const unsigned char *input, | 
|  | unsigned char *output); | 
|  |  | 
|  | /** | 
|  | * \brief            This function performs a PKCS#1 v2.1 OAEP encryption | 
|  | *                   operation (RSAES-OAEP-ENCRYPT). | 
|  | * | 
|  | * \note             The output buffer must be as large as the size | 
|  | *                   of ctx->N. For example, 128 Bytes if RSA-1024 is used. | 
|  | * | 
|  | * \deprecated       It is deprecated and discouraged to call this function | 
|  | *                   in #MBEDTLS_RSA_PRIVATE mode. Future versions of the library | 
|  | *                   are likely to remove the \p mode argument and have it | 
|  | *                   implicitly set to #MBEDTLS_RSA_PUBLIC. | 
|  | * | 
|  | * \note             Alternative implementations of RSA need not support | 
|  | *                   mode being set to #MBEDTLS_RSA_PRIVATE and might instead | 
|  | *                   return #MBEDTLS_ERR_PLATFORM_FEATURE_UNSUPPORTED. | 
|  | * | 
|  | * \param ctx        The initialized RSA context to use. | 
|  | * \param f_rng      The RNG function to use. This is needed for padding | 
|  | *                   generation and must be provided. | 
|  | * \param p_rng      The RNG context to be passed to \p f_rng. This may | 
|  | *                   be \c NULL if \p f_rng doesn't need a context argument. | 
|  | * \param mode       The mode of operation. This must be either | 
|  | *                   #MBEDTLS_RSA_PUBLIC or #MBEDTLS_RSA_PRIVATE (deprecated). | 
|  | * \param label      The buffer holding the custom label to use. | 
|  | *                   This must be a readable buffer of length \p label_len | 
|  | *                   Bytes. It may be \c NULL if \p label_len is \c 0. | 
|  | * \param label_len  The length of the label in Bytes. | 
|  | * \param ilen       The length of the plaintext buffer \p input in Bytes. | 
|  | * \param input      The input data to encrypt. This must be a readable | 
|  | *                   buffer of size \p ilen Bytes. It may be \c NULL if | 
|  | *                   `ilen == 0`. | 
|  | * \param output     The output buffer. This must be a writable buffer | 
|  | *                   of length \c ctx->len Bytes. For example, \c 256 Bytes | 
|  | *                   for an 2048-bit RSA modulus. | 
|  | * | 
|  | * \return           \c 0 on success. | 
|  | * \return           An \c MBEDTLS_ERR_RSA_XXX error code on failure. | 
|  | */ | 
|  | int mbedtls_rsa_rsaes_oaep_encrypt(mbedtls_rsa_context *ctx, | 
|  | int (*f_rng)(void *, unsigned char *, size_t), | 
|  | void *p_rng, | 
|  | int mode, | 
|  | const unsigned char *label, size_t label_len, | 
|  | size_t ilen, | 
|  | const unsigned char *input, | 
|  | unsigned char *output); | 
|  |  | 
|  | /** | 
|  | * \brief          This function performs an RSA operation, then removes the | 
|  | *                 message padding. | 
|  | * | 
|  | *                 It is the generic wrapper for performing a PKCS#1 decryption | 
|  | *                 operation using the \p mode from the context. | 
|  | * | 
|  | * \note           The output buffer length \c output_max_len should be | 
|  | *                 as large as the size \p ctx->len of \p ctx->N (for example, | 
|  | *                 128 Bytes if RSA-1024 is used) to be able to hold an | 
|  | *                 arbitrary decrypted message. If it is not large enough to | 
|  | *                 hold the decryption of the particular ciphertext provided, | 
|  | *                 the function returns \c MBEDTLS_ERR_RSA_OUTPUT_TOO_LARGE. | 
|  | * | 
|  | * \deprecated     It is deprecated and discouraged to call this function | 
|  | *                 in #MBEDTLS_RSA_PUBLIC mode. Future versions of the library | 
|  | *                 are likely to remove the \p mode argument and have it | 
|  | *                 implicitly set to #MBEDTLS_RSA_PRIVATE. | 
|  | * | 
|  | * \note           Alternative implementations of RSA need not support | 
|  | *                 mode being set to #MBEDTLS_RSA_PUBLIC and might instead | 
|  | *                 return #MBEDTLS_ERR_PLATFORM_FEATURE_UNSUPPORTED. | 
|  | * | 
|  | * \param ctx      The initialized RSA context to use. | 
|  | * \param f_rng    The RNG function. If \p mode is #MBEDTLS_RSA_PRIVATE, | 
|  | *                 this is used for blinding and should be provided; see | 
|  | *                 mbedtls_rsa_private() for more. If \p mode is | 
|  | *                 #MBEDTLS_RSA_PUBLIC, it is ignored. | 
|  | * \param p_rng    The RNG context to be passed to \p f_rng. This may be | 
|  | *                 \c NULL if \p f_rng is \c NULL or doesn't need a context. | 
|  | * \param mode     The mode of operation. This must be either | 
|  | *                 #MBEDTLS_RSA_PRIVATE or #MBEDTLS_RSA_PUBLIC (deprecated). | 
|  | * \param olen     The address at which to store the length of | 
|  | *                 the plaintext. This must not be \c NULL. | 
|  | * \param input    The ciphertext buffer. This must be a readable buffer | 
|  | *                 of length \c ctx->len Bytes. For example, \c 256 Bytes | 
|  | *                 for an 2048-bit RSA modulus. | 
|  | * \param output   The buffer used to hold the plaintext. This must | 
|  | *                 be a writable buffer of length \p output_max_len Bytes. | 
|  | * \param output_max_len The length in Bytes of the output buffer \p output. | 
|  | * | 
|  | * \return         \c 0 on success. | 
|  | * \return         An \c MBEDTLS_ERR_RSA_XXX error code on failure. | 
|  | */ | 
|  | int mbedtls_rsa_pkcs1_decrypt(mbedtls_rsa_context *ctx, | 
|  | int (*f_rng)(void *, unsigned char *, size_t), | 
|  | void *p_rng, | 
|  | int mode, size_t *olen, | 
|  | const unsigned char *input, | 
|  | unsigned char *output, | 
|  | size_t output_max_len); | 
|  |  | 
|  | /** | 
|  | * \brief          This function performs a PKCS#1 v1.5 decryption | 
|  | *                 operation (RSAES-PKCS1-v1_5-DECRYPT). | 
|  | * | 
|  | * \note           The output buffer length \c output_max_len should be | 
|  | *                 as large as the size \p ctx->len of \p ctx->N, for example, | 
|  | *                 128 Bytes if RSA-1024 is used, to be able to hold an | 
|  | *                 arbitrary decrypted message. If it is not large enough to | 
|  | *                 hold the decryption of the particular ciphertext provided, | 
|  | *                 the function returns #MBEDTLS_ERR_RSA_OUTPUT_TOO_LARGE. | 
|  | * | 
|  | * \deprecated     It is deprecated and discouraged to call this function | 
|  | *                 in #MBEDTLS_RSA_PUBLIC mode. Future versions of the library | 
|  | *                 are likely to remove the \p mode argument and have it | 
|  | *                 implicitly set to #MBEDTLS_RSA_PRIVATE. | 
|  | * | 
|  | * \note           Alternative implementations of RSA need not support | 
|  | *                 mode being set to #MBEDTLS_RSA_PUBLIC and might instead | 
|  | *                 return #MBEDTLS_ERR_PLATFORM_FEATURE_UNSUPPORTED. | 
|  | * | 
|  | * \param ctx      The initialized RSA context to use. | 
|  | * \param f_rng    The RNG function. If \p mode is #MBEDTLS_RSA_PRIVATE, | 
|  | *                 this is used for blinding and should be provided; see | 
|  | *                 mbedtls_rsa_private() for more. If \p mode is | 
|  | *                 #MBEDTLS_RSA_PUBLIC, it is ignored. | 
|  | * \param p_rng    The RNG context to be passed to \p f_rng. This may be | 
|  | *                 \c NULL if \p f_rng is \c NULL or doesn't need a context. | 
|  | * \param mode     The mode of operation. This must be either | 
|  | *                 #MBEDTLS_RSA_PRIVATE or #MBEDTLS_RSA_PUBLIC (deprecated). | 
|  | * \param olen     The address at which to store the length of | 
|  | *                 the plaintext. This must not be \c NULL. | 
|  | * \param input    The ciphertext buffer. This must be a readable buffer | 
|  | *                 of length \c ctx->len Bytes. For example, \c 256 Bytes | 
|  | *                 for an 2048-bit RSA modulus. | 
|  | * \param output   The buffer used to hold the plaintext. This must | 
|  | *                 be a writable buffer of length \p output_max_len Bytes. | 
|  | * \param output_max_len The length in Bytes of the output buffer \p output. | 
|  | * | 
|  | * \return         \c 0 on success. | 
|  | * \return         An \c MBEDTLS_ERR_RSA_XXX error code on failure. | 
|  | * | 
|  | */ | 
|  | int mbedtls_rsa_rsaes_pkcs1_v15_decrypt(mbedtls_rsa_context *ctx, | 
|  | int (*f_rng)(void *, unsigned char *, size_t), | 
|  | void *p_rng, | 
|  | int mode, size_t *olen, | 
|  | const unsigned char *input, | 
|  | unsigned char *output, | 
|  | size_t output_max_len); | 
|  |  | 
|  | /** | 
|  | * \brief            This function performs a PKCS#1 v2.1 OAEP decryption | 
|  | *                   operation (RSAES-OAEP-DECRYPT). | 
|  | * | 
|  | * \note             The output buffer length \c output_max_len should be | 
|  | *                   as large as the size \p ctx->len of \p ctx->N, for | 
|  | *                   example, 128 Bytes if RSA-1024 is used, to be able to | 
|  | *                   hold an arbitrary decrypted message. If it is not | 
|  | *                   large enough to hold the decryption of the particular | 
|  | *                   ciphertext provided, the function returns | 
|  | *                   #MBEDTLS_ERR_RSA_OUTPUT_TOO_LARGE. | 
|  | * | 
|  | * \deprecated       It is deprecated and discouraged to call this function | 
|  | *                   in #MBEDTLS_RSA_PUBLIC mode. Future versions of the library | 
|  | *                   are likely to remove the \p mode argument and have it | 
|  | *                   implicitly set to #MBEDTLS_RSA_PRIVATE. | 
|  | * | 
|  | * \note             Alternative implementations of RSA need not support | 
|  | *                   mode being set to #MBEDTLS_RSA_PUBLIC and might instead | 
|  | *                   return #MBEDTLS_ERR_PLATFORM_FEATURE_UNSUPPORTED. | 
|  | * | 
|  | * \param ctx        The initialized RSA context to use. | 
|  | * \param f_rng      The RNG function. If \p mode is #MBEDTLS_RSA_PRIVATE, | 
|  | *                   this is used for blinding and should be provided; see | 
|  | *                   mbedtls_rsa_private() for more. If \p mode is | 
|  | *                   #MBEDTLS_RSA_PUBLIC, it is ignored. | 
|  | * \param p_rng      The RNG context to be passed to \p f_rng. This may be | 
|  | *                   \c NULL if \p f_rng is \c NULL or doesn't need a context. | 
|  | * \param mode       The mode of operation. This must be either | 
|  | *                   #MBEDTLS_RSA_PRIVATE or #MBEDTLS_RSA_PUBLIC (deprecated). | 
|  | * \param label      The buffer holding the custom label to use. | 
|  | *                   This must be a readable buffer of length \p label_len | 
|  | *                   Bytes. It may be \c NULL if \p label_len is \c 0. | 
|  | * \param label_len  The length of the label in Bytes. | 
|  | * \param olen       The address at which to store the length of | 
|  | *                   the plaintext. This must not be \c NULL. | 
|  | * \param input      The ciphertext buffer. This must be a readable buffer | 
|  | *                   of length \c ctx->len Bytes. For example, \c 256 Bytes | 
|  | *                   for an 2048-bit RSA modulus. | 
|  | * \param output     The buffer used to hold the plaintext. This must | 
|  | *                   be a writable buffer of length \p output_max_len Bytes. | 
|  | * \param output_max_len The length in Bytes of the output buffer \p output. | 
|  | * | 
|  | * \return         \c 0 on success. | 
|  | * \return         An \c MBEDTLS_ERR_RSA_XXX error code on failure. | 
|  | */ | 
|  | int mbedtls_rsa_rsaes_oaep_decrypt(mbedtls_rsa_context *ctx, | 
|  | int (*f_rng)(void *, unsigned char *, size_t), | 
|  | void *p_rng, | 
|  | int mode, | 
|  | const unsigned char *label, size_t label_len, | 
|  | size_t *olen, | 
|  | const unsigned char *input, | 
|  | unsigned char *output, | 
|  | size_t output_max_len); | 
|  |  | 
|  | /** | 
|  | * \brief          This function performs a private RSA operation to sign | 
|  | *                 a message digest using PKCS#1. | 
|  | * | 
|  | *                 It is the generic wrapper for performing a PKCS#1 | 
|  | *                 signature using the \p mode from the context. | 
|  | * | 
|  | * \note           The \p sig buffer must be as large as the size | 
|  | *                 of \p ctx->N. For example, 128 Bytes if RSA-1024 is used. | 
|  | * | 
|  | * \note           For PKCS#1 v2.1 encoding, see comments on | 
|  | *                 mbedtls_rsa_rsassa_pss_sign() for details on | 
|  | *                 \p md_alg and \p hash_id. | 
|  | * | 
|  | * \deprecated     It is deprecated and discouraged to call this function | 
|  | *                 in #MBEDTLS_RSA_PUBLIC mode. Future versions of the library | 
|  | *                 are likely to remove the \p mode argument and have it | 
|  | *                 implicitly set to #MBEDTLS_RSA_PRIVATE. | 
|  | * | 
|  | * \note           Alternative implementations of RSA need not support | 
|  | *                 mode being set to #MBEDTLS_RSA_PUBLIC and might instead | 
|  | *                 return #MBEDTLS_ERR_PLATFORM_FEATURE_UNSUPPORTED. | 
|  | * | 
|  | * \param ctx      The initialized RSA context to use. | 
|  | * \param f_rng    The RNG function to use. If the padding mode is PKCS#1 v2.1, | 
|  | *                 this must be provided. If the padding mode is PKCS#1 v1.5 and | 
|  | *                 \p mode is #MBEDTLS_RSA_PRIVATE, it is used for blinding | 
|  | *                 and should be provided; see mbedtls_rsa_private() for more | 
|  | *                 more. It is ignored otherwise. | 
|  | * \param p_rng    The RNG context to be passed to \p f_rng. This may be \c NULL | 
|  | *                 if \p f_rng is \c NULL or doesn't need a context argument. | 
|  | * \param mode     The mode of operation. This must be either | 
|  | *                 #MBEDTLS_RSA_PRIVATE or #MBEDTLS_RSA_PUBLIC (deprecated). | 
|  | * \param md_alg   The message-digest algorithm used to hash the original data. | 
|  | *                 Use #MBEDTLS_MD_NONE for signing raw data. | 
|  | * \param hashlen  The length of the message digest. | 
|  | *                 Ths is only used if \p md_alg is #MBEDTLS_MD_NONE. | 
|  | * \param hash     The buffer holding the message digest or raw data. | 
|  | *                 If \p md_alg is #MBEDTLS_MD_NONE, this must be a readable | 
|  | *                 buffer of length \p hashlen Bytes. If \p md_alg is not | 
|  | *                 #MBEDTLS_MD_NONE, it must be a readable buffer of length | 
|  | *                 the size of the hash corresponding to \p md_alg. | 
|  | * \param sig      The buffer to hold the signature. This must be a writable | 
|  | *                 buffer of length \c ctx->len Bytes. For example, \c 256 Bytes | 
|  | *                 for an 2048-bit RSA modulus. A buffer length of | 
|  | *                 #MBEDTLS_MPI_MAX_SIZE is always safe. | 
|  | * | 
|  | * \return         \c 0 if the signing operation was successful. | 
|  | * \return         An \c MBEDTLS_ERR_RSA_XXX error code on failure. | 
|  | */ | 
|  | int mbedtls_rsa_pkcs1_sign(mbedtls_rsa_context *ctx, | 
|  | int (*f_rng)(void *, unsigned char *, size_t), | 
|  | void *p_rng, | 
|  | int mode, | 
|  | mbedtls_md_type_t md_alg, | 
|  | unsigned int hashlen, | 
|  | const unsigned char *hash, | 
|  | unsigned char *sig); | 
|  |  | 
|  | /** | 
|  | * \brief          This function performs a PKCS#1 v1.5 signature | 
|  | *                 operation (RSASSA-PKCS1-v1_5-SIGN). | 
|  | * | 
|  | * \deprecated     It is deprecated and discouraged to call this function | 
|  | *                 in #MBEDTLS_RSA_PUBLIC mode. Future versions of the library | 
|  | *                 are likely to remove the \p mode argument and have it | 
|  | *                 implicitly set to #MBEDTLS_RSA_PRIVATE. | 
|  | * | 
|  | * \note           Alternative implementations of RSA need not support | 
|  | *                 mode being set to #MBEDTLS_RSA_PUBLIC and might instead | 
|  | *                 return #MBEDTLS_ERR_PLATFORM_FEATURE_UNSUPPORTED. | 
|  | * | 
|  | * \param ctx      The initialized RSA context to use. | 
|  | * \param f_rng    The RNG function. If \p mode is #MBEDTLS_RSA_PRIVATE, | 
|  | *                 this is used for blinding and should be provided; see | 
|  | *                 mbedtls_rsa_private() for more. If \p mode is | 
|  | *                 #MBEDTLS_RSA_PUBLIC, it is ignored. | 
|  | * \param p_rng    The RNG context to be passed to \p f_rng. This may be \c NULL | 
|  | *                 if \p f_rng is \c NULL or doesn't need a context argument. | 
|  | * \param mode     The mode of operation. This must be either | 
|  | *                 #MBEDTLS_RSA_PRIVATE or #MBEDTLS_RSA_PUBLIC (deprecated). | 
|  | * \param md_alg   The message-digest algorithm used to hash the original data. | 
|  | *                 Use #MBEDTLS_MD_NONE for signing raw data. | 
|  | * \param hashlen  The length of the message digest. | 
|  | *                 Ths is only used if \p md_alg is #MBEDTLS_MD_NONE. | 
|  | * \param hash     The buffer holding the message digest or raw data. | 
|  | *                 If \p md_alg is #MBEDTLS_MD_NONE, this must be a readable | 
|  | *                 buffer of length \p hashlen Bytes. If \p md_alg is not | 
|  | *                 #MBEDTLS_MD_NONE, it must be a readable buffer of length | 
|  | *                 the size of the hash corresponding to \p md_alg. | 
|  | * \param sig      The buffer to hold the signature. This must be a writable | 
|  | *                 buffer of length \c ctx->len Bytes. For example, \c 256 Bytes | 
|  | *                 for an 2048-bit RSA modulus. A buffer length of | 
|  | *                 #MBEDTLS_MPI_MAX_SIZE is always safe. | 
|  | * | 
|  | * \return         \c 0 if the signing operation was successful. | 
|  | * \return         An \c MBEDTLS_ERR_RSA_XXX error code on failure. | 
|  | */ | 
|  | int mbedtls_rsa_rsassa_pkcs1_v15_sign(mbedtls_rsa_context *ctx, | 
|  | int (*f_rng)(void *, unsigned char *, size_t), | 
|  | void *p_rng, | 
|  | int mode, | 
|  | mbedtls_md_type_t md_alg, | 
|  | unsigned int hashlen, | 
|  | const unsigned char *hash, | 
|  | unsigned char *sig); | 
|  |  | 
|  | /** | 
|  | * \brief          This function performs a PKCS#1 v2.1 PSS signature | 
|  | *                 operation (RSASSA-PSS-SIGN). | 
|  | * | 
|  | * \note           The \c hash_id set in \p ctx (when calling | 
|  | *                 mbedtls_rsa_init() or by calling mbedtls_rsa_set_padding() | 
|  | *                 afterwards) selects the hash used for the | 
|  | *                 encoding operation and for the mask generation function | 
|  | *                 (MGF1). For more details on the encoding operation and the | 
|  | *                 mask generation function, consult <em>RFC-3447: Public-Key | 
|  | *                 Cryptography Standards (PKCS) #1 v2.1: RSA Cryptography | 
|  | *                 Specifications</em>. | 
|  | * | 
|  | * \note           This function enforces that the provided salt length complies | 
|  | *                 with FIPS 186-4 §5.5 (e) and RFC 8017 (PKCS#1 v2.2) §9.1.1 | 
|  | *                 step 3. The constraint is that the hash length plus the salt | 
|  | *                 length plus 2 bytes must be at most the key length. If this | 
|  | *                 constraint is not met, this function returns | 
|  | *                 #MBEDTLS_ERR_RSA_BAD_INPUT_DATA. | 
|  | * | 
|  | * \param ctx      The initialized RSA context to use. | 
|  | * \param f_rng    The RNG function. It must not be \c NULL. | 
|  | * \param p_rng    The RNG context to be passed to \p f_rng. This may be \c NULL | 
|  | *                 if \p f_rng doesn't need a context argument. | 
|  | * \param md_alg   The message-digest algorithm used to hash the original data. | 
|  | *                 Use #MBEDTLS_MD_NONE for signing raw data. | 
|  | * \param hashlen  The length of the message digest. | 
|  | *                 Ths is only used if \p md_alg is #MBEDTLS_MD_NONE. | 
|  | * \param hash     The buffer holding the message digest or raw data. | 
|  | *                 If \p md_alg is #MBEDTLS_MD_NONE, this must be a readable | 
|  | *                 buffer of length \p hashlen Bytes. If \p md_alg is not | 
|  | *                 #MBEDTLS_MD_NONE, it must be a readable buffer of length | 
|  | *                 the size of the hash corresponding to \p md_alg. | 
|  | * \param saltlen  The length of the salt that should be used. | 
|  | *                 If passed #MBEDTLS_RSA_SALT_LEN_ANY, the function will use | 
|  | *                 the largest possible salt length up to the hash length, | 
|  | *                 which is the largest permitted by some standards including | 
|  | *                 FIPS 186-4 §5.5. | 
|  | * \param sig      The buffer to hold the signature. This must be a writable | 
|  | *                 buffer of length \c ctx->len Bytes. For example, \c 256 Bytes | 
|  | *                 for an 2048-bit RSA modulus. A buffer length of | 
|  | *                 #MBEDTLS_MPI_MAX_SIZE is always safe. | 
|  | * | 
|  | * \return         \c 0 if the signing operation was successful. | 
|  | * \return         An \c MBEDTLS_ERR_RSA_XXX error code on failure. | 
|  | */ | 
|  | int mbedtls_rsa_rsassa_pss_sign_ext(mbedtls_rsa_context *ctx, | 
|  | int (*f_rng)(void *, unsigned char *, size_t), | 
|  | void *p_rng, | 
|  | mbedtls_md_type_t md_alg, | 
|  | unsigned int hashlen, | 
|  | const unsigned char *hash, | 
|  | int saltlen, | 
|  | unsigned char *sig); | 
|  |  | 
|  | /** | 
|  | * \brief          This function performs a PKCS#1 v2.1 PSS signature | 
|  | *                 operation (RSASSA-PSS-SIGN). | 
|  | * | 
|  | * \note           The \c hash_id set in \p ctx (when calling | 
|  | *                 mbedtls_rsa_init() or by calling mbedtls_rsa_set_padding() | 
|  | *                 afterwards) selects the hash used for the | 
|  | *                 encoding operation and for the mask generation function | 
|  | *                 (MGF1). For more details on the encoding operation and the | 
|  | *                 mask generation function, consult <em>RFC-3447: Public-Key | 
|  | *                 Cryptography Standards (PKCS) #1 v2.1: RSA Cryptography | 
|  | *                 Specifications</em>. | 
|  | * | 
|  | * \note           This function always uses the maximum possible salt size, | 
|  | *                 up to the length of the payload hash. This choice of salt | 
|  | *                 size complies with FIPS 186-4 §5.5 (e) and RFC 8017 (PKCS#1 | 
|  | *                 v2.2) §9.1.1 step 3. Furthermore this function enforces a | 
|  | *                 minimum salt size which is the hash size minus 2 bytes. If | 
|  | *                 this minimum size is too large given the key size (the salt | 
|  | *                 size, plus the hash size, plus 2 bytes must be no more than | 
|  | *                 the key size in bytes), this function returns | 
|  | *                 #MBEDTLS_ERR_RSA_BAD_INPUT_DATA. | 
|  | * | 
|  | * \deprecated     It is deprecated and discouraged to call this function | 
|  | *                 in #MBEDTLS_RSA_PUBLIC mode. Future versions of the library | 
|  | *                 are likely to remove the \p mode argument and have it | 
|  | *                 implicitly set to #MBEDTLS_RSA_PRIVATE. | 
|  | * | 
|  | * \note           Alternative implementations of RSA need not support | 
|  | *                 mode being set to #MBEDTLS_RSA_PUBLIC and might instead | 
|  | *                 return #MBEDTLS_ERR_PLATFORM_FEATURE_UNSUPPORTED. | 
|  | * | 
|  | * \param ctx      The initialized RSA context to use. | 
|  | * \param f_rng    The RNG function. It must not be \c NULL. | 
|  | * \param p_rng    The RNG context to be passed to \p f_rng. This may be \c NULL | 
|  | *                 if \p f_rng doesn't need a context argument. | 
|  | * \param mode     The mode of operation. This must be either | 
|  | *                 #MBEDTLS_RSA_PRIVATE or #MBEDTLS_RSA_PUBLIC (deprecated). | 
|  | * \param md_alg   The message-digest algorithm used to hash the original data. | 
|  | *                 Use #MBEDTLS_MD_NONE for signing raw data. | 
|  | * \param hashlen  The length of the message digest. | 
|  | *                 This is only used if \p md_alg is #MBEDTLS_MD_NONE. | 
|  | * \param hash     The buffer holding the message digest or raw data. | 
|  | *                 If \p md_alg is #MBEDTLS_MD_NONE, this must be a readable | 
|  | *                 buffer of length \p hashlen Bytes. If \p md_alg is not | 
|  | *                 #MBEDTLS_MD_NONE, it must be a readable buffer of length | 
|  | *                 the size of the hash corresponding to \p md_alg. | 
|  | * \param sig      The buffer to hold the signature. This must be a writable | 
|  | *                 buffer of length \c ctx->len Bytes. For example, \c 256 Bytes | 
|  | *                 for an 2048-bit RSA modulus. A buffer length of | 
|  | *                 #MBEDTLS_MPI_MAX_SIZE is always safe. | 
|  | * | 
|  | * \return         \c 0 if the signing operation was successful. | 
|  | * \return         An \c MBEDTLS_ERR_RSA_XXX error code on failure. | 
|  | */ | 
|  | int mbedtls_rsa_rsassa_pss_sign(mbedtls_rsa_context *ctx, | 
|  | int (*f_rng)(void *, unsigned char *, size_t), | 
|  | void *p_rng, | 
|  | int mode, | 
|  | mbedtls_md_type_t md_alg, | 
|  | unsigned int hashlen, | 
|  | const unsigned char *hash, | 
|  | unsigned char *sig); | 
|  |  | 
|  | /** | 
|  | * \brief          This function performs a public RSA operation and checks | 
|  | *                 the message digest. | 
|  | * | 
|  | *                 This is the generic wrapper for performing a PKCS#1 | 
|  | *                 verification using the mode from the context. | 
|  | * | 
|  | * \note           For PKCS#1 v2.1 encoding, see comments on | 
|  | *                 mbedtls_rsa_rsassa_pss_verify() about \c md_alg and | 
|  | *                 \c hash_id. | 
|  | * | 
|  | * \deprecated     It is deprecated and discouraged to call this function | 
|  | *                 in #MBEDTLS_RSA_PRIVATE mode. Future versions of the library | 
|  | *                 are likely to remove the \p mode argument and have it | 
|  | *                 set to #MBEDTLS_RSA_PUBLIC. | 
|  | * | 
|  | * \note           Alternative implementations of RSA need not support | 
|  | *                 mode being set to #MBEDTLS_RSA_PRIVATE and might instead | 
|  | *                 return #MBEDTLS_ERR_PLATFORM_FEATURE_UNSUPPORTED. | 
|  | * | 
|  | * \param ctx      The initialized RSA public key context to use. | 
|  | * \param f_rng    The RNG function to use. If \p mode is #MBEDTLS_RSA_PRIVATE, | 
|  | *                 this is used for blinding and should be provided; see | 
|  | *                 mbedtls_rsa_private() for more. Otherwise, it is ignored. | 
|  | * \param p_rng    The RNG context to be passed to \p f_rng. This may be | 
|  | *                 \c NULL if \p f_rng is \c NULL or doesn't need a context. | 
|  | * \param mode     The mode of operation. This must be either | 
|  | *                 #MBEDTLS_RSA_PUBLIC or #MBEDTLS_RSA_PRIVATE (deprecated). | 
|  | * \param md_alg   The message-digest algorithm used to hash the original data. | 
|  | *                 Use #MBEDTLS_MD_NONE for signing raw data. | 
|  | * \param hashlen  The length of the message digest. | 
|  | *                 This is only used if \p md_alg is #MBEDTLS_MD_NONE. | 
|  | * \param hash     The buffer holding the message digest or raw data. | 
|  | *                 If \p md_alg is #MBEDTLS_MD_NONE, this must be a readable | 
|  | *                 buffer of length \p hashlen Bytes. If \p md_alg is not | 
|  | *                 #MBEDTLS_MD_NONE, it must be a readable buffer of length | 
|  | *                 the size of the hash corresponding to \p md_alg. | 
|  | * \param sig      The buffer holding the signature. This must be a readable | 
|  | *                 buffer of length \c ctx->len Bytes. For example, \c 256 Bytes | 
|  | *                 for an 2048-bit RSA modulus. | 
|  | * | 
|  | * \return         \c 0 if the verify operation was successful. | 
|  | * \return         An \c MBEDTLS_ERR_RSA_XXX error code on failure. | 
|  | */ | 
|  | int mbedtls_rsa_pkcs1_verify(mbedtls_rsa_context *ctx, | 
|  | int (*f_rng)(void *, unsigned char *, size_t), | 
|  | void *p_rng, | 
|  | int mode, | 
|  | mbedtls_md_type_t md_alg, | 
|  | unsigned int hashlen, | 
|  | const unsigned char *hash, | 
|  | const unsigned char *sig); | 
|  |  | 
|  | /** | 
|  | * \brief          This function performs a PKCS#1 v1.5 verification | 
|  | *                 operation (RSASSA-PKCS1-v1_5-VERIFY). | 
|  | * | 
|  | * \deprecated     It is deprecated and discouraged to call this function | 
|  | *                 in #MBEDTLS_RSA_PRIVATE mode. Future versions of the library | 
|  | *                 are likely to remove the \p mode argument and have it | 
|  | *                 set to #MBEDTLS_RSA_PUBLIC. | 
|  | * | 
|  | * \note           Alternative implementations of RSA need not support | 
|  | *                 mode being set to #MBEDTLS_RSA_PRIVATE and might instead | 
|  | *                 return #MBEDTLS_ERR_PLATFORM_FEATURE_UNSUPPORTED. | 
|  | * | 
|  | * \param ctx      The initialized RSA public key context to use. | 
|  | * \param f_rng    The RNG function to use. If \p mode is #MBEDTLS_RSA_PRIVATE, | 
|  | *                 this is used for blinding and should be provided; see | 
|  | *                 mbedtls_rsa_private() for more. Otherwise, it is ignored. | 
|  | * \param p_rng    The RNG context to be passed to \p f_rng. This may be | 
|  | *                 \c NULL if \p f_rng is \c NULL or doesn't need a context. | 
|  | * \param mode     The mode of operation. This must be either | 
|  | *                 #MBEDTLS_RSA_PUBLIC or #MBEDTLS_RSA_PRIVATE (deprecated). | 
|  | * \param md_alg   The message-digest algorithm used to hash the original data. | 
|  | *                 Use #MBEDTLS_MD_NONE for signing raw data. | 
|  | * \param hashlen  The length of the message digest. | 
|  | *                 This is only used if \p md_alg is #MBEDTLS_MD_NONE. | 
|  | * \param hash     The buffer holding the message digest or raw data. | 
|  | *                 If \p md_alg is #MBEDTLS_MD_NONE, this must be a readable | 
|  | *                 buffer of length \p hashlen Bytes. If \p md_alg is not | 
|  | *                 #MBEDTLS_MD_NONE, it must be a readable buffer of length | 
|  | *                 the size of the hash corresponding to \p md_alg. | 
|  | * \param sig      The buffer holding the signature. This must be a readable | 
|  | *                 buffer of length \c ctx->len Bytes. For example, \c 256 Bytes | 
|  | *                 for an 2048-bit RSA modulus. | 
|  | * | 
|  | * \return         \c 0 if the verify operation was successful. | 
|  | * \return         An \c MBEDTLS_ERR_RSA_XXX error code on failure. | 
|  | */ | 
|  | int mbedtls_rsa_rsassa_pkcs1_v15_verify(mbedtls_rsa_context *ctx, | 
|  | int (*f_rng)(void *, unsigned char *, size_t), | 
|  | void *p_rng, | 
|  | int mode, | 
|  | mbedtls_md_type_t md_alg, | 
|  | unsigned int hashlen, | 
|  | const unsigned char *hash, | 
|  | const unsigned char *sig); | 
|  |  | 
|  | /** | 
|  | * \brief          This function performs a PKCS#1 v2.1 PSS verification | 
|  | *                 operation (RSASSA-PSS-VERIFY). | 
|  | * | 
|  | * \note           The \c hash_id set in \p ctx (when calling | 
|  | *                 mbedtls_rsa_init() or by calling mbedtls_rsa_set_padding() | 
|  | *                 afterwards) selects the hash used for the | 
|  | *                 encoding operation and for the mask generation function | 
|  | *                 (MGF1). For more details on the encoding operation and the | 
|  | *                 mask generation function, consult <em>RFC-3447: Public-Key | 
|  | *                 Cryptography Standards (PKCS) #1 v2.1: RSA Cryptography | 
|  | *                 Specifications</em>. If the \c hash_id set in \p ctx is | 
|  | *                 #MBEDTLS_MD_NONE, the \p md_alg parameter is used. | 
|  | * | 
|  | * \deprecated     It is deprecated and discouraged to call this function | 
|  | *                 in #MBEDTLS_RSA_PRIVATE mode. Future versions of the library | 
|  | *                 are likely to remove the \p mode argument and have it | 
|  | *                 implicitly set to #MBEDTLS_RSA_PUBLIC. | 
|  | * | 
|  | * \note           Alternative implementations of RSA need not support | 
|  | *                 mode being set to #MBEDTLS_RSA_PRIVATE and might instead | 
|  | *                 return #MBEDTLS_ERR_PLATFORM_FEATURE_UNSUPPORTED. | 
|  | * | 
|  | * \param ctx      The initialized RSA public key context to use. | 
|  | * \param f_rng    The RNG function to use. If \p mode is #MBEDTLS_RSA_PRIVATE, | 
|  | *                 this is used for blinding and should be provided; see | 
|  | *                 mbedtls_rsa_private() for more. Otherwise, it is ignored. | 
|  | * \param p_rng    The RNG context to be passed to \p f_rng. This may be | 
|  | *                 \c NULL if \p f_rng is \c NULL or doesn't need a context. | 
|  | * \param mode     The mode of operation. This must be either | 
|  | *                 #MBEDTLS_RSA_PUBLIC or #MBEDTLS_RSA_PRIVATE (deprecated). | 
|  | * \param md_alg   The message-digest algorithm used to hash the original data. | 
|  | *                 Use #MBEDTLS_MD_NONE for signing raw data. | 
|  | * \param hashlen  The length of the message digest. | 
|  | *                 This is only used if \p md_alg is #MBEDTLS_MD_NONE. | 
|  | * \param hash     The buffer holding the message digest or raw data. | 
|  | *                 If \p md_alg is #MBEDTLS_MD_NONE, this must be a readable | 
|  | *                 buffer of length \p hashlen Bytes. If \p md_alg is not | 
|  | *                 #MBEDTLS_MD_NONE, it must be a readable buffer of length | 
|  | *                 the size of the hash corresponding to \p md_alg. | 
|  | * \param sig      The buffer holding the signature. This must be a readable | 
|  | *                 buffer of length \c ctx->len Bytes. For example, \c 256 Bytes | 
|  | *                 for an 2048-bit RSA modulus. | 
|  | * | 
|  | * \return         \c 0 if the verify operation was successful. | 
|  | * \return         An \c MBEDTLS_ERR_RSA_XXX error code on failure. | 
|  | */ | 
|  | int mbedtls_rsa_rsassa_pss_verify(mbedtls_rsa_context *ctx, | 
|  | int (*f_rng)(void *, unsigned char *, size_t), | 
|  | void *p_rng, | 
|  | int mode, | 
|  | mbedtls_md_type_t md_alg, | 
|  | unsigned int hashlen, | 
|  | const unsigned char *hash, | 
|  | const unsigned char *sig); | 
|  |  | 
|  | /** | 
|  | * \brief          This function performs a PKCS#1 v2.1 PSS verification | 
|  | *                 operation (RSASSA-PSS-VERIFY). | 
|  | * | 
|  | * \note           The \p sig buffer must be as large as the size | 
|  | *                 of \p ctx->N. For example, 128 Bytes if RSA-1024 is used. | 
|  | * | 
|  | * \note           The \c hash_id set in \p ctx (when calling | 
|  | *                 mbedtls_rsa_init() or by calling mbedtls_rsa_set_padding() | 
|  | *                 afterwards) is ignored. | 
|  | * | 
|  | * \param ctx      The initialized RSA public key context to use. | 
|  | * \param f_rng    The RNG function to use. If \p mode is #MBEDTLS_RSA_PRIVATE, | 
|  | *                 this is used for blinding and should be provided; see | 
|  | *                 mbedtls_rsa_private() for more. Otherwise, it is ignored. | 
|  | * \param p_rng    The RNG context to be passed to \p f_rng. This may be | 
|  | *                 \c NULL if \p f_rng is \c NULL or doesn't need a context. | 
|  | * \param mode     The mode of operation. This must be either | 
|  | *                 #MBEDTLS_RSA_PUBLIC or #MBEDTLS_RSA_PRIVATE. | 
|  | * \param md_alg   The message-digest algorithm used to hash the original data. | 
|  | *                 Use #MBEDTLS_MD_NONE for signing raw data. | 
|  | * \param hashlen  The length of the message digest. | 
|  | *                 This is only used if \p md_alg is #MBEDTLS_MD_NONE. | 
|  | * \param hash     The buffer holding the message digest or raw data. | 
|  | *                 If \p md_alg is #MBEDTLS_MD_NONE, this must be a readable | 
|  | *                 buffer of length \p hashlen Bytes. If \p md_alg is not | 
|  | *                 #MBEDTLS_MD_NONE, it must be a readable buffer of length | 
|  | *                 the size of the hash corresponding to \p md_alg. | 
|  | * \param mgf1_hash_id      The message digest algorithm used for the | 
|  | *                          verification operation and the mask generation | 
|  | *                          function (MGF1). For more details on the encoding | 
|  | *                          operation and the mask generation function, consult | 
|  | *                          <em>RFC-3447: Public-Key Cryptography Standards | 
|  | *                          (PKCS) #1 v2.1: RSA Cryptography | 
|  | *                          Specifications</em>. | 
|  | * \param expected_salt_len The length of the salt used in padding. Use | 
|  | *                          #MBEDTLS_RSA_SALT_LEN_ANY to accept any salt length. | 
|  | * \param sig      The buffer holding the signature. This must be a readable | 
|  | *                 buffer of length \c ctx->len Bytes. For example, \c 256 Bytes | 
|  | *                 for an 2048-bit RSA modulus. | 
|  | * | 
|  | * \return         \c 0 if the verify operation was successful. | 
|  | * \return         An \c MBEDTLS_ERR_RSA_XXX error code on failure. | 
|  | */ | 
|  | int mbedtls_rsa_rsassa_pss_verify_ext(mbedtls_rsa_context *ctx, | 
|  | int (*f_rng)(void *, unsigned char *, size_t), | 
|  | void *p_rng, | 
|  | int mode, | 
|  | mbedtls_md_type_t md_alg, | 
|  | unsigned int hashlen, | 
|  | const unsigned char *hash, | 
|  | mbedtls_md_type_t mgf1_hash_id, | 
|  | int expected_salt_len, | 
|  | const unsigned char *sig); | 
|  |  | 
|  | /** | 
|  | * \brief          This function copies the components of an RSA context. | 
|  | * | 
|  | * \param dst      The destination context. This must be initialized. | 
|  | * \param src      The source context. This must be initialized. | 
|  | * | 
|  | * \return         \c 0 on success. | 
|  | * \return         #MBEDTLS_ERR_MPI_ALLOC_FAILED on memory allocation failure. | 
|  | */ | 
|  | int mbedtls_rsa_copy(mbedtls_rsa_context *dst, const mbedtls_rsa_context *src); | 
|  |  | 
|  | /** | 
|  | * \brief          This function frees the components of an RSA key. | 
|  | * | 
|  | * \param ctx      The RSA context to free. May be \c NULL, in which case | 
|  | *                 this function is a no-op. If it is not \c NULL, it must | 
|  | *                 point to an initialized RSA context. | 
|  | */ | 
|  | void mbedtls_rsa_free(mbedtls_rsa_context *ctx); | 
|  |  | 
|  | #if defined(MBEDTLS_SELF_TEST) | 
|  |  | 
|  | /** | 
|  | * \brief          The RSA checkup routine. | 
|  | * | 
|  | * \return         \c 0 on success. | 
|  | * \return         \c 1 on failure. | 
|  | */ | 
|  | int mbedtls_rsa_self_test(int verbose); | 
|  |  | 
|  | #endif /* MBEDTLS_SELF_TEST */ | 
|  |  | 
|  | #ifdef __cplusplus | 
|  | } | 
|  | #endif | 
|  |  | 
|  | #endif /* rsa.h */ |