Doug Anson
mbed TLS library
Dependents: HTTPClient-SSL WS_SERVER
Diff: include/polarssl/rsa.h
- Revision:
- 0:137634ff4186
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/include/polarssl/rsa.h Thu Jun 11 03:27:03 2015 +0000
@@ -0,0 +1,654 @@
+/**
+ * \file rsa.h
+ *
+ * \brief The RSA public-key cryptosystem
+ *
+ * Copyright (C) 2006-2014, ARM Limited, All Rights Reserved
+ *
+ * This file is part of mbed TLS (https://tls.mbed.org)
+ *
+ * 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
+
+#if !defined(POLARSSL_CONFIG_FILE)
+#include "config.h"
+#else
+#include POLARSSL_CONFIG_FILE
+#endif
+
+#include "bignum.h"
+#include "md.h"
+
+#if defined(POLARSSL_THREADING_C)
+#include "threading.h"
+#endif
+
+/*
+ * 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 library's 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. */
+
+/*
+ * RSA constants
+ */
+#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
+
+/*
+ * 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.
+ */
+#if defined(POLARSSL_RSA_C)
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/**
+ * \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 */
+
+ mpi Vi; /*!< cached blinding value */
+ mpi Vf; /*!< cached un-blinding value */
+
+ 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 */
+#if defined(POLARSSL_THREADING_C)
+ threading_mutex_t mutex; /*!< Thread-safety mutex */
+#endif
+}
+rsa_context;
+
+/**
+ * \brief Initialize an RSA context
+ *
+ * Note: Set padding to RSA_PKCS_V21 for the RSAES-OAEP
+ * encryption scheme and the RSASSA-PSS signature scheme.
+ *
+ * \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.
+ *
+ * \note 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.
+ *
+ * \note 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.
+ */
+void rsa_init( rsa_context *ctx,
+ int padding,
+ int hash_id);
+
+/**
+ * \brief Set padding for an already initialized RSA context
+ * See \c rsa_init() for details.
+ *
+ * \param ctx RSA context to be set
+ * \param padding RSA_PKCS_V15 or RSA_PKCS_V21
+ * \param hash_id RSA_PKCS_V21 hash identifier
+ */
+void rsa_set_padding( 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 Check a public-private RSA key pair.
+ * Check each of the contexts, and make sure they match.
+ *
+ * \param pub RSA context holding the public key
+ * \param prv RSA context holding the private key
+ *
+ * \return 0 if successful, or an POLARSSL_ERR_RSA_XXX error code
+ */
+int rsa_check_pub_priv( const rsa_context *pub, const rsa_context *prv );
+
+/**
+ * \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 f_rng RNG function (Needed for blinding)
+ * \param p_rng RNG parameter
+ * \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,
+ int (*f_rng)(void *, unsigned char *, size_t),
+ void *p_rng,
+ const unsigned char *input,
+ unsigned char *output );
+
+/**
+ * \brief Generic wrapper to perform a PKCS#1 encryption using the
+ * mode from the context. 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
+ * and RSA_PRIVATE)
+ * \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 Perform a PKCS#1 v1.5 encryption (RSAES-PKCS1-v1_5-ENCRYPT)
+ *
+ * \param ctx RSA context
+ * \param f_rng RNG function (Needed for padding and RSA_PRIVATE)
+ * \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_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 );
+
+/**
+ * \brief Perform a PKCS#1 v2.1 OAEP encryption (RSAES-OAEP-ENCRYPT)
+ *
+ * \param ctx RSA context
+ * \param f_rng RNG function (Needed for padding and PKCS#1 v2.1 encoding
+ * and RSA_PRIVATE)
+ * \param p_rng RNG parameter
+ * \param mode RSA_PUBLIC or RSA_PRIVATE
+ * \param label buffer holding the custom label to use
+ * \param label_len contains the label length
+ * \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_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 );
+
+/**
+ * \brief Generic wrapper to perform a PKCS#1 decryption using the
+ * mode from the context. Do an RSA operation, then remove
+ * the message padding
+ *
+ * \param ctx RSA context
+ * \param f_rng RNG function (Only needed for RSA_PRIVATE)
+ * \param p_rng RNG parameter
+ * \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 (*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 Perform a PKCS#1 v1.5 decryption (RSAES-PKCS1-v1_5-DECRYPT)
+ *
+ * \param ctx RSA context
+ * \param f_rng RNG function (Only needed for RSA_PRIVATE)
+ * \param p_rng RNG parameter
+ * \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_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 );
+
+/**
+ * \brief Perform a PKCS#1 v2.1 OAEP decryption (RSAES-OAEP-DECRYPT)
+ *
+ * \param ctx RSA context
+ * \param f_rng RNG function (Only needed for RSA_PRIVATE)
+ * \param p_rng RNG parameter
+ * \param mode RSA_PUBLIC or RSA_PRIVATE
+ * \param label buffer holding the custom label to use
+ * \param label_len contains the label length
+ * \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_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 );
+
+/**
+ * \brief Generic wrapper to perform a PKCS#1 signature using the
+ * mode from the context. Do a private RSA operation to sign
+ * a message digest
+ *
+ * \param ctx RSA context
+ * \param f_rng RNG function (Needed for PKCS#1 v2.1 encoding and for
+ * RSA_PRIVATE)
+ * \param p_rng RNG parameter
+ * \param mode RSA_PUBLIC or RSA_PRIVATE
+ * \param md_alg a POLARSSL_MD_* (use POLARSSL_MD_NONE for signing raw data)
+ * \param hashlen message digest length (for POLARSSL_MD_NONE 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, see comments on
+ * \note \c rsa_rsassa_pss_sign() for details on md_alg and hash_id.
+ */
+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 );
+
+/**
+ * \brief Perform a PKCS#1 v1.5 signature (RSASSA-PKCS1-v1_5-SIGN)
+ *
+ * \param ctx RSA context
+ * \param f_rng RNG function (Only needed for RSA_PRIVATE)
+ * \param p_rng RNG parameter
+ * \param mode RSA_PUBLIC or RSA_PRIVATE
+ * \param md_alg a POLARSSL_MD_* (use POLARSSL_MD_NONE for signing raw data)
+ * \param hashlen message digest length (for POLARSSL_MD_NONE 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).
+ */
+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 );
+
+/**
+ * \brief Perform a PKCS#1 v2.1 PSS signature (RSASSA-PSS-SIGN)
+ *
+ * \param ctx RSA context
+ * \param f_rng RNG function (Needed for PKCS#1 v2.1 encoding and for
+ * RSA_PRIVATE)
+ * \param p_rng RNG parameter
+ * \param mode RSA_PUBLIC or RSA_PRIVATE
+ * \param md_alg a POLARSSL_MD_* (use POLARSSL_MD_NONE for signing raw data)
+ * \param hashlen message digest length (for POLARSSL_MD_NONE 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 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.
+ */
+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 );
+
+/**
+ * \brief Generic wrapper to perform a PKCS#1 verification using the
+ * mode from the context. Do a public RSA operation and check
+ * the message digest
+ *
+ * \param ctx points to an RSA public key
+ * \param f_rng RNG function (Only needed for RSA_PRIVATE)
+ * \param p_rng RNG parameter
+ * \param mode RSA_PUBLIC or RSA_PRIVATE
+ * \param md_alg a POLARSSL_MD_* (use POLARSSL_MD_NONE for signing raw data)
+ * \param hashlen message digest length (for POLARSSL_MD_NONE 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, see comments on
+ * \c rsa_rsassa_pss_verify() about md_alg and hash_id.
+ */
+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 );
+
+/**
+ * \brief Perform a PKCS#1 v1.5 verification (RSASSA-PKCS1-v1_5-VERIFY)
+ *
+ * \param ctx points to an RSA public key
+ * \param f_rng RNG function (Only needed for RSA_PRIVATE)
+ * \param p_rng RNG parameter
+ * \param mode RSA_PUBLIC or RSA_PRIVATE
+ * \param md_alg a POLARSSL_MD_* (use POLARSSL_MD_NONE for signing raw data)
+ * \param hashlen message digest length (for POLARSSL_MD_NONE 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).
+ */
+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 );
+
+/**
+ * \brief Perform a PKCS#1 v2.1 PSS verification (RSASSA-PSS-VERIFY)
+ * (This is the "simple" version.)
+ *
+ * \param ctx points to an RSA public key
+ * \param f_rng RNG function (Only needed for RSA_PRIVATE)
+ * \param p_rng RNG parameter
+ * \param mode RSA_PUBLIC or RSA_PRIVATE
+ * \param md_alg a POLARSSL_MD_* (use POLARSSL_MD_NONE for signing raw data)
+ * \param hashlen message digest length (for POLARSSL_MD_NONE 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 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.
+ */
+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 );
+
+/**
+ * \brief Perform a PKCS#1 v2.1 PSS verification (RSASSA-PSS-VERIFY)
+ * (This is the version with "full" options.)
+ *
+ * \param ctx points to an RSA public key
+ * \param f_rng RNG function (Only needed for RSA_PRIVATE)
+ * \param p_rng RNG parameter
+ * \param mode RSA_PUBLIC or RSA_PRIVATE
+ * \param md_alg a POLARSSL_MD_* (use POLARSSL_MD_NONE for signing raw data)
+ * \param hashlen message digest length (for POLARSSL_MD_NONE only)
+ * \param hash buffer holding the message digest
+ * \param mgf1_hash_id message digest used for mask generation
+ * \param expected_salt_len Length of the salt used in padding, use
+ * RSA_SALT_LEN_ANY to accept any salt length
+ * \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 The hash_id in the RSA context is ignored.
+ */
+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 );
+
+/**
+ * \brief Copy the components of an RSA context
+ *
+ * \param dst Destination context
+ * \param src Source context
+ *
+ * \return O on success,
+ * POLARSSL_ERR_MPI_MALLOC_FAILED on memory allocation failure
+ */
+int rsa_copy( rsa_context *dst, const rsa_context *src );
+
+/**
+ * \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 /* POLARSSL_RSA_C */
+
+#endif /* rsa.h */
+