demos/encrypt/rsa_encrypt.c - third_party/openssl - Git at Google

 /*-
  * Copyright 2021 The OpenSSL Project Authors. All Rights Reserved.
  *
  * Licensed under the Apache License 2.0 (the "License").  You may not use
  * this file except in compliance with the License.  You can obtain a copy
  * in the file LICENSE in the source distribution or at
  * https://www.openssl.org/source/license.html
  */

 /*
  * An example that uses EVP_PKEY_encrypt and EVP_PKEY_decrypt methods
  * to encrypt and decrypt data using an RSA keypair.
  * RSA encryption produces different encrypted output each time it is run,
  * hence this is not a known answer test.
  */

 #include <stdio.h>
 #include <stdlib.h>
 #include <openssl/err.h>
 #include <openssl/evp.h>
 #include <openssl/decoder.h>
 #include <openssl/core_names.h>
 #include "rsa_encrypt.h"

 /* Input data to encrypt */
 static const unsigned char msg[] =
     "To be, or not to be, that is the question,\n"
     "Whether tis nobler in the minde to suffer\n"
     "The slings and arrowes of outragious fortune,\n"
     "Or to take Armes again in a sea of troubles";

 /*
  * For do_encrypt(), load an RSA public key from pub_key_der[].
  * For do_decrypt(), load an RSA private key from priv_key_der[].
  */
 static EVP_PKEY *get_key(OSSL_LIB_CTX *libctx, const char *propq, int public)
 {
     OSSL_DECODER_CTX *dctx = NULL;
     EVP_PKEY *pkey = NULL;
     int selection;
     const unsigned char *data;
     size_t data_len;

     if (public) {
         selection = EVP_PKEY_PUBLIC_KEY;
         data = pub_key_der;
         data_len = sizeof(pub_key_der);
     } else {
         selection = EVP_PKEY_KEYPAIR;
         data = priv_key_der;
         data_len = sizeof(priv_key_der);
     }
     dctx = OSSL_DECODER_CTX_new_for_pkey(&pkey, "DER", NULL, "RSA",
                                          selection, libctx, propq);
     (void)OSSL_DECODER_from_data(dctx, &data, &data_len);
     OSSL_DECODER_CTX_free(dctx);
     return pkey;
 }

 /* Set optional parameters for RSA OAEP Padding */
 static void set_optional_params(OSSL_PARAM *p, const char *propq)
 {
     static unsigned char label[] = "label";

     /* "pkcs1" is used by default if the padding mode is not set */
     *p++ = OSSL_PARAM_construct_utf8_string(OSSL_ASYM_CIPHER_PARAM_PAD_MODE,
                                             OSSL_PKEY_RSA_PAD_MODE_OAEP, 0);
     /* No oaep_label is used if this is not set */
     *p++ = OSSL_PARAM_construct_octet_string(OSSL_ASYM_CIPHER_PARAM_OAEP_LABEL,
                                              label, sizeof(label));
     /* "SHA1" is used if this is not set */
     *p++ = OSSL_PARAM_construct_utf8_string(OSSL_ASYM_CIPHER_PARAM_OAEP_DIGEST,
                                             "SHA256", 0);
     /*
      * If a non default property query needs to be specified when fetching the
      * OAEP digest then it needs to be specified here.
      */
     if (propq != NULL)
         *p++ = OSSL_PARAM_construct_utf8_string(OSSL_ASYM_CIPHER_PARAM_OAEP_DIGEST_PROPS,
                                                 (char *)propq, 0);

     /*
      * OSSL_ASYM_CIPHER_PARAM_MGF1_DIGEST and
      * OSSL_ASYM_CIPHER_PARAM_MGF1_DIGEST_PROPS can also be optionally added
      * here if the MGF1 digest differs from the OAEP digest.
      */

     *p = OSSL_PARAM_construct_end();
 }

 /*
  * The length of the input data that can be encrypted is limited by the
  * RSA key length minus some additional bytes that depends on the padding mode.
  *
  */
 static int do_encrypt(OSSL_LIB_CTX *libctx,
                       const unsigned char *in, size_t in_len,
                       unsigned char **out, size_t *out_len)
 {
     int ret = 0, public = 1;
     size_t buf_len = 0;
     unsigned char *buf = NULL;
     const char *propq = NULL;
     EVP_PKEY_CTX *ctx = NULL;
     EVP_PKEY *pub_key = NULL;
     OSSL_PARAM params[5];

     /* Get public key */
     pub_key = get_key(libctx, propq, public);
     if (pub_key == NULL) {
         fprintf(stderr, "Get public key failed.\n");
         goto cleanup;
     }
     ctx = EVP_PKEY_CTX_new_from_pkey(libctx, pub_key, propq);
     if (ctx == NULL) {
         fprintf(stderr, "EVP_PKEY_CTX_new_from_pkey() failed.\n");
         goto cleanup;
     }
     set_optional_params(params, propq);
     /* If no optional parameters are required then NULL can be passed */
     if (EVP_PKEY_encrypt_init_ex(ctx, params) <= 0) {
         fprintf(stderr, "EVP_PKEY_encrypt_init_ex() failed.\n");
         goto cleanup;
     }
     /* Calculate the size required to hold the encrypted data */
     if (EVP_PKEY_encrypt(ctx, NULL, &buf_len, in, in_len) <= 0) {
         fprintf(stderr, "EVP_PKEY_encrypt() failed.\n");
         goto cleanup;
     }
     buf = OPENSSL_zalloc(buf_len);
     if (buf  == NULL) {
         fprintf(stderr, "Malloc failed.\n");
         goto cleanup;
     }
     if (EVP_PKEY_encrypt(ctx, buf, &buf_len, in, in_len) <= 0) {
         fprintf(stderr, "EVP_PKEY_encrypt() failed.\n");
         goto cleanup;
     }
     *out_len = buf_len;
     *out = buf;
     fprintf(stdout, "Encrypted:\n");
     BIO_dump_indent_fp(stdout, buf, buf_len, 2);
     fprintf(stdout, "\n");
     ret = 1;

 cleanup:
     if (!ret)
         OPENSSL_free(buf);
     EVP_PKEY_free(pub_key);
     EVP_PKEY_CTX_free(ctx);
     return ret;
 }

 static int do_decrypt(OSSL_LIB_CTX *libctx, const char *in, size_t in_len,
                       unsigned char **out, size_t *out_len)
 {
     int ret = 0, public = 0;
     size_t buf_len = 0;
     unsigned char *buf = NULL;
     const char *propq = NULL;
     EVP_PKEY_CTX *ctx = NULL;
     EVP_PKEY *priv_key = NULL;
     OSSL_PARAM params[5];

     /* Get private key */
     priv_key = get_key(libctx, propq, public);
     if (priv_key == NULL) {
         fprintf(stderr, "Get private key failed.\n");
         goto cleanup;
     }
     ctx = EVP_PKEY_CTX_new_from_pkey(libctx, priv_key, propq);
     if (ctx == NULL) {
         fprintf(stderr, "EVP_PKEY_CTX_new_from_pkey() failed.\n");
         goto cleanup;
     }

     /* The parameters used for encryption must also be used for decryption */
     set_optional_params(params, propq);
     /* If no optional parameters are required then NULL can be passed */
     if (EVP_PKEY_decrypt_init_ex(ctx, params) <= 0) {
         fprintf(stderr, "EVP_PKEY_decrypt_init_ex() failed.\n");
         goto cleanup;
     }
     /* Calculate the size required to hold the decrypted data */
     if (EVP_PKEY_decrypt(ctx, NULL, &buf_len, in, in_len) <= 0) {
         fprintf(stderr, "EVP_PKEY_decrypt() failed.\n");
         goto cleanup;
     }
     buf = OPENSSL_zalloc(buf_len);
     if (buf == NULL) {
         fprintf(stderr, "Malloc failed.\n");
         goto cleanup;
     }
     if (EVP_PKEY_decrypt(ctx, buf, &buf_len, in, in_len) <= 0) {
         fprintf(stderr, "EVP_PKEY_decrypt() failed.\n");
         goto cleanup;
     }
     *out_len = buf_len;
     *out = buf;
     fprintf(stdout, "Decrypted:\n");
     BIO_dump_indent_fp(stdout, buf, buf_len, 2);
     fprintf(stdout, "\n");
     ret = 1;

 cleanup:
     if (!ret)
         OPENSSL_free(buf);
     EVP_PKEY_free(priv_key);
     EVP_PKEY_CTX_free(ctx);
     return ret;
 }

 int main(void)
 {
     int ret = EXIT_FAILURE;
     size_t msg_len = sizeof(msg) - 1;
     size_t encrypted_len = 0, decrypted_len = 0;
     unsigned char *encrypted = NULL, *decrypted = NULL;
     OSSL_LIB_CTX *libctx = NULL;

     if (!do_encrypt(libctx, msg, msg_len, &encrypted, &encrypted_len)) {
         fprintf(stderr, "encryption failed.\n");
         goto cleanup;
     }
     if (!do_decrypt(libctx, encrypted, encrypted_len,
                     &decrypted, &decrypted_len)) {
         fprintf(stderr, "decryption failed.\n");
         goto cleanup;
     }
     if (CRYPTO_memcmp(msg, decrypted, decrypted_len) != 0) {
         fprintf(stderr, "Decrypted data does not match expected value\n");
         goto cleanup;
     }
     ret = EXIT_SUCCESS;

 cleanup:
     OPENSSL_free(decrypted);
     OPENSSL_free(encrypted);
     OSSL_LIB_CTX_free(libctx);
     if (ret != EXIT_SUCCESS)
         ERR_print_errors_fp(stderr);
     return ret;
 }
	/*-
	* Copyright 2021 The OpenSSL Project Authors. All Rights Reserved.
	*
	* Licensed under the Apache License 2.0 (the "License"). You may not use
	* this file except in compliance with the License. You can obtain a copy
	* in the file LICENSE in the source distribution or at
	* https://www.openssl.org/source/license.html
	*/

	/*
	* An example that uses EVP_PKEY_encrypt and EVP_PKEY_decrypt methods
	* to encrypt and decrypt data using an RSA keypair.
	* RSA encryption produces different encrypted output each time it is run,
	* hence this is not a known answer test.
	*/

	#include <stdio.h>
	#include <stdlib.h>
	#include <openssl/err.h>
	#include <openssl/evp.h>
	#include <openssl/decoder.h>
	#include <openssl/core_names.h>
	#include "rsa_encrypt.h"

	/* Input data to encrypt */
	static const unsigned char msg[] =
	"To be, or not to be, that is the question,\n"
	"Whether tis nobler in the minde to suffer\n"
	"The slings and arrowes of outragious fortune,\n"
	"Or to take Armes again in a sea of troubles";

	/*
	* For do_encrypt(), load an RSA public key from pub_key_der[].
	* For do_decrypt(), load an RSA private key from priv_key_der[].
	*/
	static EVP_PKEY get_key(OSSL_LIB_CTX libctx, const char *propq, int public)
	{
	OSSL_DECODER_CTX *dctx = NULL;
	EVP_PKEY *pkey = NULL;
	int selection;
	const unsigned char *data;
	size_t data_len;

	if (public) {
	selection = EVP_PKEY_PUBLIC_KEY;
	data = pub_key_der;
	data_len = sizeof(pub_key_der);
	} else {
	selection = EVP_PKEY_KEYPAIR;
	data = priv_key_der;
	data_len = sizeof(priv_key_der);
	}
	dctx = OSSL_DECODER_CTX_new_for_pkey(&pkey, "DER", NULL, "RSA",
	selection, libctx, propq);
	(void)OSSL_DECODER_from_data(dctx, &data, &data_len);
	OSSL_DECODER_CTX_free(dctx);
	return pkey;
	}

	/* Set optional parameters for RSA OAEP Padding */
	static void set_optional_params(OSSL_PARAM p, const char propq)
	{
	static unsigned char label[] = "label";

	/* "pkcs1" is used by default if the padding mode is not set */
	*p++ = OSSL_PARAM_construct_utf8_string(OSSL_ASYM_CIPHER_PARAM_PAD_MODE,
	OSSL_PKEY_RSA_PAD_MODE_OAEP, 0);
	/* No oaep_label is used if this is not set */
	*p++ = OSSL_PARAM_construct_octet_string(OSSL_ASYM_CIPHER_PARAM_OAEP_LABEL,
	label, sizeof(label));
	/* "SHA1" is used if this is not set */
	*p++ = OSSL_PARAM_construct_utf8_string(OSSL_ASYM_CIPHER_PARAM_OAEP_DIGEST,
	"SHA256", 0);
	/*
	* If a non default property query needs to be specified when fetching the
	* OAEP digest then it needs to be specified here.
	*/
	if (propq != NULL)
	*p++ = OSSL_PARAM_construct_utf8_string(OSSL_ASYM_CIPHER_PARAM_OAEP_DIGEST_PROPS,
	(char *)propq, 0);

	/*
	* OSSL_ASYM_CIPHER_PARAM_MGF1_DIGEST and
	* OSSL_ASYM_CIPHER_PARAM_MGF1_DIGEST_PROPS can also be optionally added
	* here if the MGF1 digest differs from the OAEP digest.
	*/

	*p = OSSL_PARAM_construct_end();
	}

	/*
	* The length of the input data that can be encrypted is limited by the
	* RSA key length minus some additional bytes that depends on the padding mode.
	*
	*/
	static int do_encrypt(OSSL_LIB_CTX *libctx,
	const unsigned char *in, size_t in_len,
	unsigned char *out, size_t out_len)
	{
	int ret = 0, public = 1;
	size_t buf_len = 0;
	unsigned char *buf = NULL;
	const char *propq = NULL;
	EVP_PKEY_CTX *ctx = NULL;
	EVP_PKEY *pub_key = NULL;
	OSSL_PARAM params[5];

	/* Get public key */
	pub_key = get_key(libctx, propq, public);
	if (pub_key == NULL) {
	fprintf(stderr, "Get public key failed.\n");
	goto cleanup;
	}
	ctx = EVP_PKEY_CTX_new_from_pkey(libctx, pub_key, propq);
	if (ctx == NULL) {
	fprintf(stderr, "EVP_PKEY_CTX_new_from_pkey() failed.\n");
	goto cleanup;
	}
	set_optional_params(params, propq);
	/* If no optional parameters are required then NULL can be passed */
	if (EVP_PKEY_encrypt_init_ex(ctx, params) <= 0) {
	fprintf(stderr, "EVP_PKEY_encrypt_init_ex() failed.\n");
	goto cleanup;
	}
	/* Calculate the size required to hold the encrypted data */
	if (EVP_PKEY_encrypt(ctx, NULL, &buf_len, in, in_len) <= 0) {
	fprintf(stderr, "EVP_PKEY_encrypt() failed.\n");
	goto cleanup;
	}
	buf = OPENSSL_zalloc(buf_len);
	if (buf == NULL) {
	fprintf(stderr, "Malloc failed.\n");
	goto cleanup;
	}
	if (EVP_PKEY_encrypt(ctx, buf, &buf_len, in, in_len) <= 0) {
	fprintf(stderr, "EVP_PKEY_encrypt() failed.\n");
	goto cleanup;
	}
	*out_len = buf_len;
	*out = buf;
	fprintf(stdout, "Encrypted:\n");
	BIO_dump_indent_fp(stdout, buf, buf_len, 2);
	fprintf(stdout, "\n");
	ret = 1;

	cleanup:
	if (!ret)
	OPENSSL_free(buf);
	EVP_PKEY_free(pub_key);
	EVP_PKEY_CTX_free(ctx);
	return ret;
	}

	static int do_decrypt(OSSL_LIB_CTX libctx, const char in, size_t in_len,
	unsigned char *out, size_t out_len)
	{
	int ret = 0, public = 0;
	size_t buf_len = 0;
	unsigned char *buf = NULL;
	const char *propq = NULL;
	EVP_PKEY_CTX *ctx = NULL;
	EVP_PKEY *priv_key = NULL;
	OSSL_PARAM params[5];

	/* Get private key */
	priv_key = get_key(libctx, propq, public);
	if (priv_key == NULL) {
	fprintf(stderr, "Get private key failed.\n");
	goto cleanup;
	}
	ctx = EVP_PKEY_CTX_new_from_pkey(libctx, priv_key, propq);
	if (ctx == NULL) {
	fprintf(stderr, "EVP_PKEY_CTX_new_from_pkey() failed.\n");
	goto cleanup;
	}

	/* The parameters used for encryption must also be used for decryption */
	set_optional_params(params, propq);
	/* If no optional parameters are required then NULL can be passed */
	if (EVP_PKEY_decrypt_init_ex(ctx, params) <= 0) {
	fprintf(stderr, "EVP_PKEY_decrypt_init_ex() failed.\n");
	goto cleanup;
	}
	/* Calculate the size required to hold the decrypted data */
	if (EVP_PKEY_decrypt(ctx, NULL, &buf_len, in, in_len) <= 0) {
	fprintf(stderr, "EVP_PKEY_decrypt() failed.\n");
	goto cleanup;
	}
	buf = OPENSSL_zalloc(buf_len);
	if (buf == NULL) {
	fprintf(stderr, "Malloc failed.\n");
	goto cleanup;
	}
	if (EVP_PKEY_decrypt(ctx, buf, &buf_len, in, in_len) <= 0) {
	fprintf(stderr, "EVP_PKEY_decrypt() failed.\n");
	goto cleanup;
	}
	*out_len = buf_len;
	*out = buf;
	fprintf(stdout, "Decrypted:\n");
	BIO_dump_indent_fp(stdout, buf, buf_len, 2);
	fprintf(stdout, "\n");
	ret = 1;

	cleanup:
	if (!ret)
	OPENSSL_free(buf);
	EVP_PKEY_free(priv_key);
	EVP_PKEY_CTX_free(ctx);
	return ret;
	}

	int main(void)
	{
	int ret = EXIT_FAILURE;
	size_t msg_len = sizeof(msg) - 1;
	size_t encrypted_len = 0, decrypted_len = 0;
	unsigned char encrypted = NULL, decrypted = NULL;
	OSSL_LIB_CTX *libctx = NULL;

	if (!do_encrypt(libctx, msg, msg_len, &encrypted, &encrypted_len)) {
	fprintf(stderr, "encryption failed.\n");
	goto cleanup;
	}
	if (!do_decrypt(libctx, encrypted, encrypted_len,
	&decrypted, &decrypted_len)) {
	fprintf(stderr, "decryption failed.\n");
	goto cleanup;
	}
	if (CRYPTO_memcmp(msg, decrypted, decrypted_len) != 0) {
	fprintf(stderr, "Decrypted data does not match expected value\n");
	goto cleanup;
	}
	ret = EXIT_SUCCESS;

	cleanup:
	OPENSSL_free(decrypted);
	OPENSSL_free(encrypted);
	OSSL_LIB_CTX_free(libctx);
	if (ret != EXIT_SUCCESS)
	ERR_print_errors_fp(stderr);
	return ret;
	}