/**
* \file rsa.h
*
* \brief The RSA public-key cryptosystem
*
* Copyright (C) 2006-2010, Brainspark B.V.
*
* This file is part of PolarSSL (http://www.polarssl.org)
* Lead Maintainer: Paul Bakker <polarssl_maintainer at polarssl.org>
*
* All rights reserved.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#ifndef POLARSSL_RSA_H
#define POLARSSL_RSA_H
#include "bignum.h"
/*
* RSA Error codes
*/
#define POLARSSL_ERR_RSA_BAD_INPUT_DATA -0x4080 /**< Bad input parameters to function. */
#define POLARSSL_ERR_RSA_INVALID_PADDING -0x4100 /**< Input data contains invalid padding and is rejected. */
#define POLARSSL_ERR_RSA_KEY_GEN_FAILED -0x4180 /**< Something failed during generation of a key. */
#define POLARSSL_ERR_RSA_KEY_CHECK_FAILED -0x4200 /**< Key failed to pass the libraries validity check. */
#define POLARSSL_ERR_RSA_PUBLIC_FAILED -0x4280 /**< The public key operation failed. */
#define POLARSSL_ERR_RSA_PRIVATE_FAILED -0x4300 /**< The private key operation failed. */
#define POLARSSL_ERR_RSA_VERIFY_FAILED -0x4380 /**< The PKCS#1 verification failed. */
#define POLARSSL_ERR_RSA_OUTPUT_TOO_LARGE -0x4400 /**< The output buffer for decryption is not large enough. */
#define POLARSSL_ERR_RSA_RNG_FAILED -0x4480 /**< The random generator failed to generate non-zeros. */
/*
* PKCS#1 constants
*/
#define SIG_RSA_RAW 0
#define SIG_RSA_MD2 2
#define SIG_RSA_MD4 3
#define SIG_RSA_MD5 4
#define SIG_RSA_SHA1 5
#define SIG_RSA_SHA224 14
#define SIG_RSA_SHA256 11
#define SIG_RSA_SHA384 12
#define SIG_RSA_SHA512 13
#define RSA_PUBLIC 0
#define RSA_PRIVATE 1
#define RSA_PKCS_V15 0
#define RSA_PKCS_V21 1
#define RSA_SIGN 1
#define RSA_CRYPT 2
#define ASN1_STR_CONSTRUCTED_SEQUENCE "\x30"
#define ASN1_STR_NULL "\x05"
#define ASN1_STR_OID "\x06"
#define ASN1_STR_OCTET_STRING "\x04"
#define OID_DIGEST_ALG_MDX "\x2A\x86\x48\x86\xF7\x0D\x02\x00"
#define OID_HASH_ALG_SHA1 "\x2b\x0e\x03\x02\x1a"
#define OID_HASH_ALG_SHA2X "\x60\x86\x48\x01\x65\x03\x04\x02\x00"
#define OID_ISO_MEMBER_BODIES "\x2a"
#define OID_ISO_IDENTIFIED_ORG "\x2b"
/*
* ISO Member bodies OID parts
*/
#define OID_COUNTRY_US "\x86\x48"
#define OID_RSA_DATA_SECURITY "\x86\xf7\x0d"
/*
* ISO Identified organization OID parts
*/
#define OID_OIW_SECSIG_SHA1 "\x0e\x03\x02\x1a"
/*
* DigestInfo ::= SEQUENCE {
* digestAlgorithm DigestAlgorithmIdentifier,
* digest Digest }
*
* DigestAlgorithmIdentifier ::= AlgorithmIdentifier
*
* Digest ::= OCTET STRING
*/
#define ASN1_HASH_MDX \
( \
ASN1_STR_CONSTRUCTED_SEQUENCE "\x20" \
ASN1_STR_CONSTRUCTED_SEQUENCE "\x0C" \
ASN1_STR_OID "\x08" \
OID_DIGEST_ALG_MDX \
ASN1_STR_NULL "\x00" \
ASN1_STR_OCTET_STRING "\x10" \
)
#define ASN1_HASH_SHA1 \
ASN1_STR_CONSTRUCTED_SEQUENCE "\x21" \
ASN1_STR_CONSTRUCTED_SEQUENCE "\x09" \
ASN1_STR_OID "\x05" \
OID_HASH_ALG_SHA1 \
ASN1_STR_NULL "\x00" \
ASN1_STR_OCTET_STRING "\x14"
#define ASN1_HASH_SHA2X \
ASN1_STR_CONSTRUCTED_SEQUENCE "\x11" \
ASN1_STR_CONSTRUCTED_SEQUENCE "\x0d" \
ASN1_STR_OID "\x09" \
OID_HASH_ALG_SHA2X \
ASN1_STR_NULL "\x00" \
ASN1_STR_OCTET_STRING "\x00"
/**
* \brief RSA context structure
*/
typedef struct
{
int ver; /*!< always 0 */
size_t len; /*!< size(N) in chars */
mpi N; /*!< public modulus */
mpi E; /*!< public exponent */
mpi D; /*!< private exponent */
mpi P; /*!< 1st prime factor */
mpi Q; /*!< 2nd prime factor */
mpi DP; /*!< D % (P - 1) */
mpi DQ; /*!< D % (Q - 1) */
mpi QP; /*!< 1 / (Q % P) */
mpi RN; /*!< cached R^2 mod N */
mpi RP; /*!< cached R^2 mod P */
mpi RQ; /*!< cached R^2 mod Q */
int padding; /*!< RSA_PKCS_V15 for 1.5 padding and
RSA_PKCS_v21 for OAEP/PSS */
int hash_id; /*!< Hash identifier of md_type_t as
specified in the md.h header file
for the EME-OAEP and EMSA-PSS
encoding */
}
rsa_context;
#ifdef __cplusplus
extern "C" {
#endif
/**
* \brief Initialize an RSA context
*
* \param ctx RSA context to be initialized
* \param padding RSA_PKCS_V15 or RSA_PKCS_V21
* \param hash_id RSA_PKCS_V21 hash identifier
*
* \note The hash_id parameter is actually ignored
* when using RSA_PKCS_V15 padding.
*/
void rsa_init( rsa_context *ctx,
int padding,
int hash_id);
/**
* \brief Generate an RSA keypair
*
* \param ctx RSA context that will hold the key
* \param f_rng RNG function
* \param p_rng RNG parameter
* \param nbits size of the public key in bits
* \param exponent public exponent (e.g., 65537)
*
* \note rsa_init() must be called beforehand to setup
* the RSA context.
*
* \return 0 if successful, or an POLARSSL_ERR_RSA_XXX error code
*/
int rsa_gen_key( rsa_context *ctx,
int (*f_rng)(void *, unsigned char *, size_t),
void *p_rng,
unsigned int nbits, int exponent );
/**
* \brief Check a public RSA key
*
* \param ctx RSA context to be checked
*
* \return 0 if successful, or an POLARSSL_ERR_RSA_XXX error code
*/
int rsa_check_pubkey( const rsa_context *ctx );
/**
* \brief Check a private RSA key
*
* \param ctx RSA context to be checked
*
* \return 0 if successful, or an POLARSSL_ERR_RSA_XXX error code
*/
int rsa_check_privkey( const rsa_context *ctx );
/**
* \brief Do an RSA public key operation
*
* \param ctx RSA context
* \param input input buffer
* \param output output buffer
*
* \return 0 if successful, or an POLARSSL_ERR_RSA_XXX error code
*
* \note This function does NOT take care of message
* padding. Also, be sure to set input[0] = 0 or assure that
* input is smaller than N.
*
* \note The input and output buffers must be large
* enough (eg. 128 bytes if RSA-1024 is used).
*/
int rsa_public( rsa_context *ctx,
const unsigned char *input,
unsigned char *output );
/**
* \brief Do an RSA private key operation
*
* \param ctx RSA context
* \param input input buffer
* \param output output buffer
*
* \return 0 if successful, or an POLARSSL_ERR_RSA_XXX error code
*
* \note The input and output buffers must be large
* enough (eg. 128 bytes if RSA-1024 is used).
*/
int rsa_private( rsa_context *ctx,
const unsigned char *input,
unsigned char *output );
/**
* \brief Add the message padding, then do an RSA operation
*
* \param ctx RSA context
* \param f_rng RNG function (Needed for padding and PKCS#1 v2.1 encoding)
* \param p_rng RNG parameter
* \param mode RSA_PUBLIC or RSA_PRIVATE
* \param ilen contains the plaintext length
* \param input buffer holding the data to be encrypted
* \param output buffer that will hold the ciphertext
*
* \return 0 if successful, or an POLARSSL_ERR_RSA_XXX error code
*
* \note The output buffer must be as large as the size
* of ctx->N (eg. 128 bytes if RSA-1024 is used).
*/
int rsa_pkcs1_encrypt( 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 Do an RSA operation, then remove the message padding
*
* \param ctx RSA context
* \param mode RSA_PUBLIC or RSA_PRIVATE
* \param olen will contain the plaintext length
* \param input buffer holding the encrypted data
* \param output buffer that will hold the plaintext
* \param output_max_len maximum length of the output buffer
*
* \return 0 if successful, or an POLARSSL_ERR_RSA_XXX error code
*
* \note The output buffer must be as large as the size
* of ctx->N (eg. 128 bytes if RSA-1024 is used) otherwise
* an error is thrown.
*/
int rsa_pkcs1_decrypt( rsa_context *ctx,
int mode, size_t *olen,
const unsigned char *input,
unsigned char *output,
size_t output_max_len );
/**
* \brief Do a private RSA to sign a message digest
*
* \param ctx RSA context
* \param f_rng RNG function (Needed for PKCS#1 v2.1 encoding)
* \param p_rng RNG parameter
* \param mode RSA_PUBLIC or RSA_PRIVATE
* \param hash_id SIG_RSA_RAW, SIG_RSA_MD{2,4,5} or SIG_RSA_SHA{1,224,256,384,512}
* \param hashlen message digest length (for SIG_RSA_RAW only)
* \param hash buffer holding the message digest
* \param sig buffer that will hold the ciphertext
*
* \return 0 if the signing operation was successful,
* or an POLARSSL_ERR_RSA_XXX error code
*
* \note The "sig" buffer must be as large as the size
* of ctx->N (eg. 128 bytes if RSA-1024 is used).
*
* \note In case of PKCS#1 v2.1 encoding keep in mind that
* the hash_id in the RSA context is the one used for the
* encoding. hash_id in the function call is the type of hash
* that is encoded. According to RFC 3447 it is advised to
* keep both hashes the same.
*/
int rsa_pkcs1_sign( rsa_context *ctx,
int (*f_rng)(void *, unsigned char *, size_t),
void *p_rng,
int mode,
int hash_id,
unsigned int hashlen,
const unsigned char *hash,
unsigned char *sig );
/**
* \brief Do a public RSA and check the message digest
*
* \param ctx points to an RSA public key
* \param mode RSA_PUBLIC or RSA_PRIVATE
* \param hash_id SIG_RSA_RAW, SIG_RSA_MD{2,4,5} or SIG_RSA_SHA{1,224,256,384,512}
* \param hashlen message digest length (for SIG_RSA_RAW only)
* \param hash buffer holding the message digest
* \param sig buffer holding the ciphertext
*
* \return 0 if the verify operation was successful,
* or an POLARSSL_ERR_RSA_XXX error code
*
* \note The "sig" buffer must be as large as the size
* of ctx->N (eg. 128 bytes if RSA-1024 is used).
*
* \note In case of PKCS#1 v2.1 encoding keep in mind that
* the hash_id in the RSA context is the one used for the
* verification. hash_id in the function call is the type of hash
* that is verified. According to RFC 3447 it is advised to
* keep both hashes the same.
*/
int rsa_pkcs1_verify( rsa_context *ctx,
int mode,
int hash_id,
unsigned int hashlen,
const unsigned char *hash,
unsigned char *sig );
/**
* \brief Free the components of an RSA key
*
* \param ctx RSA Context to free
*/
void rsa_free( rsa_context *ctx );
/**
* \brief Checkup routine
*
* \return 0 if successful, or 1 if the test failed
*/
int rsa_self_test( int verbose );
#ifdef __cplusplus
}
#endif
#endif /* rsa.h */