blob: cffbe3b5086c0d133636415194dcae70ab924613 [file] [log] [blame]
/**
* \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
#include "mbedtls/private_access.h"
#include "mbedtls/build_info.h"
#include "mbedtls/bignum.h"
#include "mbedtls/md.h"
#if defined(MBEDTLS_THREADING_C)
#include "mbedtls/threading.h"
#endif
/*
* RSA Error codes
*/
#define MBEDTLS_ERR_RSA_BAD_INPUT_DATA -0x4080 /**< Bad input parameters to function. */
#define MBEDTLS_ERR_RSA_INVALID_PADDING -0x4100 /**< Input data contains invalid padding and is rejected. */
#define MBEDTLS_ERR_RSA_KEY_GEN_FAILED -0x4180 /**< Something failed during generation of a key. */
#define MBEDTLS_ERR_RSA_KEY_CHECK_FAILED -0x4200 /**< Key failed to pass the validity check of the library. */
#define MBEDTLS_ERR_RSA_PUBLIC_FAILED -0x4280 /**< The public key operation failed. */
#define MBEDTLS_ERR_RSA_PRIVATE_FAILED -0x4300 /**< The private key operation failed. */
#define MBEDTLS_ERR_RSA_VERIFY_FAILED -0x4380 /**< The PKCS#1 verification failed. */
#define MBEDTLS_ERR_RSA_OUTPUT_TOO_LARGE -0x4400 /**< The output buffer for decryption is not large enough. */
#define MBEDTLS_ERR_RSA_RNG_FAILED -0x4480 /**< The random generator failed to generate non-zeros. */
/*
* RSA constants
*/
#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 implemenations in the PK layers.
*/
#ifdef __cplusplus
extern "C" {
#endif
#if !defined(MBEDTLS_RSA_ALT)
// Regular implementation
//
/**
* \brief The RSA context structure.
*/
typedef struct mbedtls_rsa_context
{
int MBEDTLS_PRIVATE(ver); /*!< Reserved for internal purposes.
* Do not set this field in application
* code. Its meaning might change without
* notice. */
size_t MBEDTLS_PRIVATE(len); /*!< The size of \p N in Bytes. */
mbedtls_mpi MBEDTLS_PRIVATE(N); /*!< The public modulus. */
mbedtls_mpi MBEDTLS_PRIVATE(E); /*!< The public exponent. */
mbedtls_mpi MBEDTLS_PRIVATE(D); /*!< The private exponent. */
mbedtls_mpi MBEDTLS_PRIVATE(P); /*!< The first prime factor. */
mbedtls_mpi MBEDTLS_PRIVATE(Q); /*!< The second prime factor. */
mbedtls_mpi MBEDTLS_PRIVATE(DP); /*!< <code>D % (P - 1)</code>. */
mbedtls_mpi MBEDTLS_PRIVATE(DQ); /*!< <code>D % (Q - 1)</code>. */
mbedtls_mpi MBEDTLS_PRIVATE(QP); /*!< <code>1 / (Q % P)</code>. */
mbedtls_mpi MBEDTLS_PRIVATE(RN); /*!< cached <code>R^2 mod N</code>. */
mbedtls_mpi MBEDTLS_PRIVATE(RP); /*!< cached <code>R^2 mod P</code>. */
mbedtls_mpi MBEDTLS_PRIVATE(RQ); /*!< cached <code>R^2 mod Q</code>. */
mbedtls_mpi MBEDTLS_PRIVATE(Vi); /*!< The cached blinding value. */
mbedtls_mpi MBEDTLS_PRIVATE(Vf); /*!< The cached un-blinding value. */
int MBEDTLS_PRIVATE(padding); /*!< Selects padding mode:
#MBEDTLS_RSA_PKCS_V15 for 1.5 padding and
#MBEDTLS_RSA_PKCS_V21 for OAEP or PSS. */
int MBEDTLS_PRIVATE(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 MBEDTLS_PRIVATE(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 This function initializes the padding and the hash
* identifier to respectively #MBEDTLS_RSA_PKCS_V15 and
* #MBEDTLS_MD_NONE. See mbedtls_rsa_set_padding() for more
* information about those parameters.
*
* \param ctx The RSA context to initialize. This must not be \c NULL.
*/
void mbedtls_rsa_init( mbedtls_rsa_context *ctx );
/**
* \brief This function sets padding for an already initialized 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 mbedtls_rsa_rsaes_xxx or \c mbedtls_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 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 hash identifier for PSS or OAEP, if \p padding is
* #MBEDTLS_RSA_PKCS_V21. #MBEDTLS_MD_NONE is accepted by this
* function but may be not suitable for some operations.
* Ignored if \p padding is #MBEDTLS_RSA_PKCS_V15.
*
* \return \c 0 on success.
* \return #MBEDTLS_ERR_RSA_INVALID_PADDING failure:
* \p padding or \p hash_id is invalid.
*/
int mbedtls_rsa_set_padding( mbedtls_rsa_context *ctx, int padding,
mbedtls_md_type_t 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 \p N and \p 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 \p P, \p Q from \p N, \p D, \p E.</li>
* <li>Derive \p N, \p D from \p P, \p Q, \p 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 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 is mandatory and 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 an 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 \p 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 exponentation
* 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 mandatory.
* \param p_rng The RNG context to pass to \p f_rng. This may be \c NULL
* 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.
*
* \param ctx The initialized RSA context to use.
* \param f_rng The RNG to use. It is used for padding generation
* and it is mandatory.
* \param p_rng The RNG context to be passed to \p f_rng. May be
* \c NULL if \p f_rng doesn't need a context argument.
* \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,
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).
*
* \param ctx The initialized RSA context to use.
* \param f_rng The RNG function to use. It is mandatory and used for
* padding generation.
* \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 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,
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.
*
* \param ctx The initnialized RSA context to use.
* \param f_rng The RNG function to use. This is needed for padding
* generation and is mandatory.
* \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 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,
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.
*
* \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.
*
* \param ctx The initialized RSA context to use.
* \param f_rng The RNG function. This is used for blinding and is
* mandatory; see mbedtls_rsa_private() for more.
* \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 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,
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.
*
* \param ctx The initialized RSA context to use.
* \param f_rng The RNG function. This is used for blinding and is
* mandatory; see mbedtls_rsa_private() for more.
* \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 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,
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.
*
* \param ctx The initialized RSA context to use.
* \param f_rng The RNG function. This is used for blinding and is
* mandatory.
* \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 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,
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.
*
* \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.
*
* \param ctx The initialized RSA context to use.
* \param f_rng The RNG function to use. This is mandatory and
* 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 or raw data in Bytes.
* If \p md_alg is not #MBEDTLS_MD_NONE, this must match the
* output length of the corresponding hash algorithm.
* \param hash The buffer holding the message digest or raw data.
* This must be a readable buffer of at least \p hashlen Bytes.
* \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,
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).
*
* \param ctx The initialized RSA context to use.
* \param f_rng The RNG function. This is used for blinding and is
* mandatory; see mbedtls_rsa_private() for more.
* \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 or raw data in Bytes.
* If \p md_alg is not #MBEDTLS_MD_NONE, this must match the
* output length of the corresponding hash algorithm.
* \param hash The buffer holding the message digest or raw data.
* This must be a readable buffer of at least \p hashlen Bytes.
* \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,
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 by calling
* mbedtls_rsa_set_padding() 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 is mandatory and 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 or raw data in Bytes.
* If \p md_alg is not #MBEDTLS_MD_NONE, this must match the
* output length of the corresponding hash algorithm.
* \param hash The buffer holding the message digest or raw data.
* This must be a readable buffer of at least \p hashlen Bytes.
* \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 by calling
* mbedtls_rsa_set_padding() 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.
*
* \param ctx The initialized RSA context to use.
* \param f_rng The RNG function. It is mandatory and 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 or raw data in Bytes.
* If \p md_alg is not #MBEDTLS_MD_NONE, this must match the
* output length of the corresponding hash algorithm.
* \param hash The buffer holding the message digest or raw data.
* This must be a readable buffer of at least \p hashlen Bytes.
* \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,
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.
*
* \note For PKCS#1 v2.1 encoding, see comments on
* mbedtls_rsa_rsassa_pss_verify() about \p md_alg and
* \p hash_id.
*
* \param ctx The initialized RSA public key context to use.
* \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 or raw data in Bytes.
* If \p md_alg is not #MBEDTLS_MD_NONE, this must match the
* output length of the corresponding hash algorithm.
* \param hash The buffer holding the message digest or raw data.
* This must be a readable buffer of at least \p hashlen Bytes.
* \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,
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).
*
* \param ctx The initialized RSA public key context to use.
* \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 or raw data in Bytes.
* If \p md_alg is not #MBEDTLS_MD_NONE, this must match the
* output length of the corresponding hash algorithm.
* \param hash The buffer holding the message digest or raw data.
* This must be a readable buffer of at least \p hashlen Bytes.
* \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,
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 by calling
* mbedtls_rsa_set_padding() 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 by
* mbedtls_rsa_set_padding() is #MBEDTLS_MD_NONE, the \p md_alg
* parameter is used.
*
* \param ctx The initialized RSA public key context to use.
* \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 or raw data in Bytes.
* If \p md_alg is not #MBEDTLS_MD_NONE, this must match the
* output length of the corresponding hash algorithm.
* \param hash The buffer holding the message digest or raw data.
* This must be a readable buffer of at least \p hashlen Bytes.
* \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,
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 by mbedtls_rsa_set_padding() is
* ignored.
*
* \param ctx The initialized RSA public key context to use.
* \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 or raw data in Bytes.
* If \p md_alg is not #MBEDTLS_MD_NONE, this must match the
* output length of the corresponding hash algorithm.
* \param hash The buffer holding the message digest or raw data.
* This must be a readable buffer of at least \p hashlen Bytes.
* \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,
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 */