rsa.h File Reference

The RSA public-key cryptosystem. More...

#include "config.h"
#include "bignum.h"
#include "md.h"

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Data Structures
struct	rsa_context
	RSA context structure. More...

Macros
#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.
#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	RSA_SALT_LEN_ANY   -1

Functions
void	rsa_init (rsa_context *ctx, int padding, int hash_id)
	Initialize an RSA context.
void	rsa_set_padding (rsa_context *ctx, int padding, int hash_id)
	Set padding for an already initialized RSA context See rsa_init() for details.
int	rsa_gen_key (rsa_context *ctx, int(*f_rng)(void *, unsigned char *, size_t), void *p_rng, unsigned int nbits, int exponent)
	Generate an RSA keypair.
int	rsa_check_pubkey (const rsa_context *ctx)
	Check a public RSA key.
int	rsa_check_privkey (const rsa_context *ctx)
	Check a private RSA key.
int	rsa_public (rsa_context *ctx, const unsigned char *input, unsigned char *output)
	Do an RSA public key operation.
int	rsa_private (rsa_context *ctx, int(*f_rng)(void *, unsigned char *, size_t), void *p_rng, const unsigned char *input, unsigned char *output)
	Do an RSA private key operation.
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)
	Generic wrapper to perform a PKCS#1 encryption using the mode from the context.
int	rsa_rsaes_pkcs1_v15_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)
	Perform a PKCS#1 v1.5 encryption (RSAES-PKCS1-v1_5-ENCRYPT)
int	rsa_rsaes_oaep_encrypt (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)
	Perform a PKCS#1 v2.1 OAEP encryption (RSAES-OAEP-ENCRYPT)
int	rsa_pkcs1_decrypt (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)
	Generic wrapper to perform a PKCS#1 decryption using the mode from the context.
int	rsa_rsaes_pkcs1_v15_decrypt (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)
	Perform a PKCS#1 v1.5 decryption (RSAES-PKCS1-v1_5-DECRYPT)
int	rsa_rsaes_oaep_decrypt (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)
	Perform a PKCS#1 v2.1 OAEP decryption (RSAES-OAEP-DECRYPT)
int	rsa_pkcs1_sign (rsa_context *ctx, int(*f_rng)(void *, unsigned char *, size_t), void *p_rng, int mode, md_type_t md_alg, unsigned int hashlen, const unsigned char *hash, unsigned char *sig)
	Generic wrapper to perform a PKCS#1 signature using the mode from the context.
int	rsa_rsassa_pkcs1_v15_sign (rsa_context *ctx, int(*f_rng)(void *, unsigned char *, size_t), void *p_rng, int mode, md_type_t md_alg, unsigned int hashlen, const unsigned char *hash, unsigned char *sig)
	Perform a PKCS#1 v1.5 signature (RSASSA-PKCS1-v1_5-SIGN)
int	rsa_rsassa_pss_sign (rsa_context *ctx, int(*f_rng)(void *, unsigned char *, size_t), void *p_rng, int mode, md_type_t md_alg, unsigned int hashlen, const unsigned char *hash, unsigned char *sig)
	Perform a PKCS#1 v2.1 PSS signature (RSASSA-PSS-SIGN)
int	rsa_pkcs1_verify (rsa_context *ctx, int(*f_rng)(void *, unsigned char *, size_t), void *p_rng, int mode, md_type_t md_alg, unsigned int hashlen, const unsigned char *hash, const unsigned char *sig)
	Generic wrapper to perform a PKCS#1 verification using the mode from the context.
int	rsa_rsassa_pkcs1_v15_verify (rsa_context *ctx, int(*f_rng)(void *, unsigned char *, size_t), void *p_rng, int mode, md_type_t md_alg, unsigned int hashlen, const unsigned char *hash, const unsigned char *sig)
	Perform a PKCS#1 v1.5 verification (RSASSA-PKCS1-v1_5-VERIFY)
int	rsa_rsassa_pss_verify (rsa_context *ctx, int(*f_rng)(void *, unsigned char *, size_t), void *p_rng, int mode, md_type_t md_alg, unsigned int hashlen, const unsigned char *hash, const unsigned char *sig)
	Perform a PKCS#1 v2.1 PSS verification (RSASSA-PSS-VERIFY) (This is the "simple" version.)
int	rsa_rsassa_pss_verify_ext (rsa_context *ctx, int(*f_rng)(void *, unsigned char *, size_t), void *p_rng, int mode, md_type_t md_alg, unsigned int hashlen, const unsigned char *hash, md_type_t mgf1_hash_id, int expected_salt_len, const unsigned char *sig)
	Perform a PKCS#1 v2.1 PSS verification (RSASSA-PSS-VERIFY) (This is the version with "full" options.)
int	rsa_copy (rsa_context *dst, const rsa_context *src)
	Copy the components of an RSA context.
void	rsa_free (rsa_context *ctx)
	Free the components of an RSA key.
int	rsa_self_test (int verbose)
	Checkup routine.

Detailed Description

The RSA public-key cryptosystem.

Copyright (C) 2006-2014, 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.

Definition in file rsa.h.

Macro Definition Documentation

POLARSSL_ERR_RSA_BAD_INPUT_DATA

#define POLARSSL_ERR_RSA_BAD_INPUT_DATA   -0x4080

Bad input parameters to function.

Definition at line 46 of file rsa.h.

POLARSSL_ERR_RSA_INVALID_PADDING

#define POLARSSL_ERR_RSA_INVALID_PADDING   -0x4100

Input data contains invalid padding and is rejected.

Definition at line 47 of file rsa.h.

POLARSSL_ERR_RSA_KEY_CHECK_FAILED

#define POLARSSL_ERR_RSA_KEY_CHECK_FAILED   -0x4200

Key failed to pass the libraries validity check.

Definition at line 49 of file rsa.h.

POLARSSL_ERR_RSA_KEY_GEN_FAILED

#define POLARSSL_ERR_RSA_KEY_GEN_FAILED   -0x4180

Something failed during generation of a key.

Definition at line 48 of file rsa.h.

POLARSSL_ERR_RSA_OUTPUT_TOO_LARGE

#define POLARSSL_ERR_RSA_OUTPUT_TOO_LARGE   -0x4400

The output buffer for decryption is not large enough.

Definition at line 53 of file rsa.h.

POLARSSL_ERR_RSA_PRIVATE_FAILED

#define POLARSSL_ERR_RSA_PRIVATE_FAILED   -0x4300

The private key operation failed.

Definition at line 51 of file rsa.h.

POLARSSL_ERR_RSA_PUBLIC_FAILED

#define POLARSSL_ERR_RSA_PUBLIC_FAILED   -0x4280

The public key operation failed.

Definition at line 50 of file rsa.h.

POLARSSL_ERR_RSA_RNG_FAILED

#define POLARSSL_ERR_RSA_RNG_FAILED   -0x4480

The random generator failed to generate non-zeros.

Definition at line 54 of file rsa.h.

POLARSSL_ERR_RSA_VERIFY_FAILED

#define POLARSSL_ERR_RSA_VERIFY_FAILED   -0x4380

The PKCS#1 verification failed.

Definition at line 52 of file rsa.h.

RSA_CRYPT

#define RSA_CRYPT   2

Definition at line 66 of file rsa.h.

RSA_PKCS_V15

#define RSA_PKCS_V15   0

Definition at line 62 of file rsa.h.

RSA_PKCS_V21

#define RSA_PKCS_V21   1

Definition at line 63 of file rsa.h.

RSA_PRIVATE

#define RSA_PRIVATE   1

Definition at line 60 of file rsa.h.

Referenced by RSA_private_decrypt(), and RSA_private_encrypt().

RSA_PUBLIC

#define RSA_PUBLIC   0

Definition at line 59 of file rsa.h.

Referenced by RSA_public_decrypt(), and RSA_public_encrypt().

RSA_SALT_LEN_ANY

#define RSA_SALT_LEN_ANY   -1

Definition at line 68 of file rsa.h.

RSA_SIGN

#define RSA_SIGN   1

Definition at line 65 of file rsa.h.

Function Documentation

rsa_check_privkey()

int rsa_check_privkey

(

const rsa_context *

ctx

)

Check a private RSA key.

Parameters

ctx	RSA context to be checked

Returns

0 if successful, or an POLARSSL_ERR_RSA_XXX error code

rsa_check_pubkey()

int rsa_check_pubkey

(

const rsa_context *

ctx

)

Check a public RSA key.

Parameters

ctx	RSA context to be checked

Returns

0 if successful, or an POLARSSL_ERR_RSA_XXX error code

rsa_copy()

int rsa_copy	(	rsa_context *	dst,
		const rsa_context *	src )

Copy the components of an RSA context.

Parameters

dst	Destination context
src	Source context

Returns

O on success, POLARSSL_ERR_MPI_MALLOC_FAILED on memory allocation failure

Referenced by x509_write_key_der(), x509_write_pubkey_der(), x509parse_key(), x509parse_keyfile(), x509parse_public_key(), and x509parse_public_keyfile().

rsa_free()

void rsa_free

(

rsa_context *

ctx

)

Free the components of an RSA key.

Parameters

ctx	RSA Context to free

Referenced by x509parse_key(), x509parse_keyfile(), x509parse_public_key(), and x509parse_public_keyfile().

rsa_gen_key()

int rsa_gen_key	(	rsa_context *	ctx,
		int(*	f_rng )(void *, unsigned char *, size_t),
		void *	p_rng,
		unsigned int	nbits,
		int	exponent )

Generate an RSA keypair.

Parameters

ctx	RSA context that will hold the key
f_rng	RNG function
p_rng	RNG parameter
nbits	size of the public key in bits
exponent	public exponent (e.g., 65537)

Note

rsa_init() must be called beforehand to setup the RSA context.

Returns

0 if successful, or an POLARSSL_ERR_RSA_XXX error code

rsa_init()

void rsa_init	(	rsa_context *	ctx,
		int	padding,
		int	hash_id )

Initialize an RSA context.

           Note: Set padding to RSA_PKCS_V21 for the RSAES-OAEP
           encryption scheme and the RSASSA-PSS signature scheme.

Parameters

ctx	RSA context to be initialized
padding	RSA_PKCS_V15 or RSA_PKCS_V21
hash_id	RSA_PKCS_V21 hash identifier

Note

The hash_id parameter is actually ignored when using RSA_PKCS_V15 padding.

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's merely a default value, which can be overriden by calling specific rsa_rsaes_xxx or rsa_rsassa_xxx functions.

The chosen hash is always used for OEAP encryption. For PSS signatures, it's always used for making signatures, but can be overriden (and always is, if set to POLARSSL_MD_NONE) for verifying them.

rsa_pkcs1_decrypt()

int rsa_pkcs1_decrypt	(	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 )

Generic wrapper to perform a PKCS#1 decryption using the mode from the context.

Do an RSA operation, then remove the message padding

Parameters

ctx	RSA context
f_rng	RNG function (Only needed for RSA_PRIVATE)
p_rng	RNG parameter
mode	RSA_PUBLIC or RSA_PRIVATE
olen	will contain the plaintext length
input	buffer holding the encrypted data
output	buffer that will hold the plaintext
output_max_len	maximum length of the output buffer

Returns

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.

Referenced by RSA_private_decrypt(), and RSA_public_decrypt().

rsa_pkcs1_encrypt()

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 )

Generic wrapper to perform a PKCS#1 encryption using the mode from the context.

Add the message padding, then do an RSA operation.

Parameters

ctx	RSA context
f_rng	RNG function (Needed for padding and PKCS#1 v2.1 encoding and RSA_PRIVATE)
p_rng	RNG parameter
mode	RSA_PUBLIC or RSA_PRIVATE
ilen	contains the plaintext length
input	buffer holding the data to be encrypted
output	buffer that will hold the ciphertext

Returns

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).

Referenced by RSA_private_encrypt(), and RSA_public_encrypt().

rsa_pkcs1_sign()

int rsa_pkcs1_sign	(	rsa_context *	ctx,
		int(*	f_rng )(void *, unsigned char *, size_t),
		void *	p_rng,
		int	mode,
		md_type_t	md_alg,
		unsigned int	hashlen,
		const unsigned char *	hash,
		unsigned char *	sig )

Generic wrapper to perform a PKCS#1 signature using the mode from the context.

Do a private RSA operation to sign a message digest

Parameters

ctx	RSA context
f_rng	RNG function (Needed for PKCS#1 v2.1 encoding and for RSA_PRIVATE)
p_rng	RNG parameter
mode	RSA_PUBLIC or RSA_PRIVATE
md_alg	a POLARSSL_MD_* (use POLARSSL_MD_NONE for signing raw data)
hashlen	message digest length (for POLARSSL_MD_NONE only)
hash	buffer holding the message digest
sig	buffer that will hold the ciphertext

Returns

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).

In case of PKCS#1 v2.1 encoding, see comments on

rsa_rsassa_pss_sign() for details on md_alg and hash_id.

rsa_pkcs1_verify()

int rsa_pkcs1_verify	(	rsa_context *	ctx,
		int(*	f_rng )(void *, unsigned char *, size_t),
		void *	p_rng,
		int	mode,
		md_type_t	md_alg,
		unsigned int	hashlen,
		const unsigned char *	hash,
		const unsigned char *	sig )

Generic wrapper to perform a PKCS#1 verification using the mode from the context.

Do a public RSA operation and check the message digest

Parameters

ctx	points to an RSA public key
f_rng	RNG function (Only needed for RSA_PRIVATE)
p_rng	RNG parameter
mode	RSA_PUBLIC or RSA_PRIVATE
md_alg	a POLARSSL_MD_* (use POLARSSL_MD_NONE for signing raw data)
hashlen	message digest length (for POLARSSL_MD_NONE only)
hash	buffer holding the message digest
sig	buffer holding the ciphertext

Returns

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).

In case of PKCS#1 v2.1 encoding, see comments on rsa_rsassa_pss_verify() about md_alg and hash_id.

rsa_private()

int rsa_private	(	rsa_context *	ctx,
		int(*	f_rng )(void *, unsigned char *, size_t),
		void *	p_rng,
		const unsigned char *	input,
		unsigned char *	output )

Do an RSA private key operation.

Parameters

ctx	RSA context
f_rng	RNG function (Needed for blinding)
p_rng	RNG parameter
input	input buffer
output	output buffer

Returns

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).

rsa_public()

int rsa_public	(	rsa_context *	ctx,
		const unsigned char *	input,
		unsigned char *	output )

Do an RSA public key operation.

Parameters

ctx	RSA context
input	input buffer
output	output buffer

Returns

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.

The input and output buffers must be large enough (eg. 128 bytes if RSA-1024 is used).

rsa_rsaes_oaep_decrypt()

int rsa_rsaes_oaep_decrypt	(	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 )

Perform a PKCS#1 v2.1 OAEP decryption (RSAES-OAEP-DECRYPT)

Parameters

ctx	RSA context
f_rng	RNG function (Only needed for RSA_PRIVATE)
p_rng	RNG parameter
mode	RSA_PUBLIC or RSA_PRIVATE
label	buffer holding the custom label to use
label_len	contains the label length
olen	will contain the plaintext length
input	buffer holding the encrypted data
output	buffer that will hold the plaintext
output_max_len	maximum length of the output buffer

Returns

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.

rsa_rsaes_oaep_encrypt()

int rsa_rsaes_oaep_encrypt	(	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 )

Perform a PKCS#1 v2.1 OAEP encryption (RSAES-OAEP-ENCRYPT)

Parameters

ctx	RSA context
f_rng	RNG function (Needed for padding and PKCS#1 v2.1 encoding and RSA_PRIVATE)
p_rng	RNG parameter
mode	RSA_PUBLIC or RSA_PRIVATE
label	buffer holding the custom label to use
label_len	contains the label length
ilen	contains the plaintext length
input	buffer holding the data to be encrypted
output	buffer that will hold the ciphertext

Returns

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).

rsa_rsaes_pkcs1_v15_decrypt()

int rsa_rsaes_pkcs1_v15_decrypt	(	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 )

Perform a PKCS#1 v1.5 decryption (RSAES-PKCS1-v1_5-DECRYPT)

Parameters

ctx	RSA context
f_rng	RNG function (Only needed for RSA_PRIVATE)
p_rng	RNG parameter
mode	RSA_PUBLIC or RSA_PRIVATE
olen	will contain the plaintext length
input	buffer holding the encrypted data
output	buffer that will hold the plaintext
output_max_len	maximum length of the output buffer

Returns

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.

rsa_rsaes_pkcs1_v15_encrypt()

int rsa_rsaes_pkcs1_v15_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 )

Perform a PKCS#1 v1.5 encryption (RSAES-PKCS1-v1_5-ENCRYPT)

Parameters

ctx	RSA context
f_rng	RNG function (Needed for padding and RSA_PRIVATE)
p_rng	RNG parameter
mode	RSA_PUBLIC or RSA_PRIVATE
ilen	contains the plaintext length
input	buffer holding the data to be encrypted
output	buffer that will hold the ciphertext

Returns

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).

rsa_rsassa_pkcs1_v15_sign()

int rsa_rsassa_pkcs1_v15_sign	(	rsa_context *	ctx,
		int(*	f_rng )(void *, unsigned char *, size_t),
		void *	p_rng,
		int	mode,
		md_type_t	md_alg,
		unsigned int	hashlen,
		const unsigned char *	hash,
		unsigned char *	sig )

Perform a PKCS#1 v1.5 signature (RSASSA-PKCS1-v1_5-SIGN)

Parameters

ctx	RSA context
f_rng	RNG function (Only needed for RSA_PRIVATE)
p_rng	RNG parameter
mode	RSA_PUBLIC or RSA_PRIVATE
md_alg	a POLARSSL_MD_* (use POLARSSL_MD_NONE for signing raw data)
hashlen	message digest length (for POLARSSL_MD_NONE only)
hash	buffer holding the message digest
sig	buffer that will hold the ciphertext

Returns

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).

rsa_rsassa_pkcs1_v15_verify()

int rsa_rsassa_pkcs1_v15_verify	(	rsa_context *	ctx,
		int(*	f_rng )(void *, unsigned char *, size_t),
		void *	p_rng,
		int	mode,
		md_type_t	md_alg,
		unsigned int	hashlen,
		const unsigned char *	hash,
		const unsigned char *	sig )

Perform a PKCS#1 v1.5 verification (RSASSA-PKCS1-v1_5-VERIFY)

Parameters

ctx	points to an RSA public key
f_rng	RNG function (Only needed for RSA_PRIVATE)
p_rng	RNG parameter
mode	RSA_PUBLIC or RSA_PRIVATE
md_alg	a POLARSSL_MD_* (use POLARSSL_MD_NONE for signing raw data)
hashlen	message digest length (for POLARSSL_MD_NONE only)
hash	buffer holding the message digest
sig	buffer holding the ciphertext

Returns

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).

rsa_rsassa_pss_sign()

int rsa_rsassa_pss_sign	(	rsa_context *	ctx,
		int(*	f_rng )(void *, unsigned char *, size_t),
		void *	p_rng,
		int	mode,
		md_type_t	md_alg,
		unsigned int	hashlen,
		const unsigned char *	hash,
		unsigned char *	sig )

Perform a PKCS#1 v2.1 PSS signature (RSASSA-PSS-SIGN)

Parameters

ctx	RSA context
f_rng	RNG function (Needed for PKCS#1 v2.1 encoding and for RSA_PRIVATE)
p_rng	RNG parameter
mode	RSA_PUBLIC or RSA_PRIVATE
md_alg	a POLARSSL_MD_* (use POLARSSL_MD_NONE for signing raw data)
hashlen	message digest length (for POLARSSL_MD_NONE only)
hash	buffer holding the message digest
sig	buffer that will hold the ciphertext

Returns

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).

The hash_id in the RSA context is the one used for the encoding. md_alg 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.

rsa_rsassa_pss_verify()

int rsa_rsassa_pss_verify	(	rsa_context *	ctx,
		int(*	f_rng )(void *, unsigned char *, size_t),
		void *	p_rng,
		int	mode,
		md_type_t	md_alg,
		unsigned int	hashlen,
		const unsigned char *	hash,
		const unsigned char *	sig )

Perform a PKCS#1 v2.1 PSS verification (RSASSA-PSS-VERIFY) (This is the "simple" version.)

Parameters

ctx	points to an RSA public key
f_rng	RNG function (Only needed for RSA_PRIVATE)
p_rng	RNG parameter
mode	RSA_PUBLIC or RSA_PRIVATE
md_alg	a POLARSSL_MD_* (use POLARSSL_MD_NONE for signing raw data)
hashlen	message digest length (for POLARSSL_MD_NONE only)
hash	buffer holding the message digest
sig	buffer holding the ciphertext

Returns

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).

The hash_id in the RSA context is the one used for the verification. md_alg 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. If hash_id in the RSA context is unset, the md_alg from the function call is used.

rsa_rsassa_pss_verify_ext()

int rsa_rsassa_pss_verify_ext	(	rsa_context *	ctx,
		int(*	f_rng )(void *, unsigned char *, size_t),
		void *	p_rng,
		int	mode,
		md_type_t	md_alg,
		unsigned int	hashlen,
		const unsigned char *	hash,
		md_type_t	mgf1_hash_id,
		int	expected_salt_len,
		const unsigned char *	sig )

Perform a PKCS#1 v2.1 PSS verification (RSASSA-PSS-VERIFY) (This is the version with "full" options.)

Parameters

ctx	points to an RSA public key
f_rng	RNG function (Only needed for RSA_PRIVATE)
p_rng	RNG parameter
mode	RSA_PUBLIC or RSA_PRIVATE
md_alg	a POLARSSL_MD_* (use POLARSSL_MD_NONE for signing raw data)
hashlen	message digest length (for POLARSSL_MD_NONE only)
hash	buffer holding the message digest
mgf1_hash_id	message digest used for mask generation
expected_salt_len	Length of the salt used in padding, use RSA_SALT_LEN_ANY to accept any salt length
sig	buffer holding the ciphertext

Returns

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).

The hash_id in the RSA context is ignored.

rsa_self_test()

int rsa_self_test

(

int

verbose

)

Checkup routine.

Returns

0 if successful, or 1 if the test failed

rsa_set_padding()

void rsa_set_padding	(	rsa_context *	ctx,
		int	padding,
		int	hash_id )

Set padding for an already initialized RSA context See rsa_init() for details.

Parameters

ctx	RSA context to be set
padding	RSA_PKCS_V15 or RSA_PKCS_V21
hash_id	RSA_PKCS_V21 hash identifier