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			624 lines
		
	
	
		
			20 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			624 lines
		
	
	
		
			20 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /*
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|  *  Public Key layer for writing key files and structures
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|  *
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|  *  Copyright The Mbed TLS Contributors
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|  *  SPDX-License-Identifier: Apache-2.0
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|  *
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|  *  Licensed under the Apache License, Version 2.0 (the "License"); you may
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|  *  not use this file except in compliance with the License.
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|  *  You may obtain a copy of the License at
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|  *
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|  *  http://www.apache.org/licenses/LICENSE-2.0
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|  *
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|  *  Unless required by applicable law or agreed to in writing, software
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|  *  distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
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|  *  WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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|  *  See the License for the specific language governing permissions and
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|  *  limitations under the License.
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|  */
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| 
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| #include "common.h"
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| 
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| #if defined(MBEDTLS_PK_WRITE_C)
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| 
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| #include "mbedtls/pk.h"
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| #include "mbedtls/asn1write.h"
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| #include "mbedtls/oid.h"
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| #include "mbedtls/platform_util.h"
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| #include "mbedtls/error.h"
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| 
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| #include <string.h>
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| 
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| #if defined(MBEDTLS_RSA_C)
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| #include "mbedtls/rsa.h"
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| #endif
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| #if defined(MBEDTLS_ECP_C)
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| #include "mbedtls/bignum.h"
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| #include "mbedtls/ecp.h"
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| #include "mbedtls/platform_util.h"
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| #endif
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| #if defined(MBEDTLS_ECDSA_C)
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| #include "mbedtls/ecdsa.h"
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| #endif
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| #if defined(MBEDTLS_PEM_WRITE_C)
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| #include "mbedtls/pem.h"
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| #endif
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| 
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| #if defined(MBEDTLS_USE_PSA_CRYPTO)
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| #include "psa/crypto.h"
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| #include "mbedtls/psa_util.h"
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| #endif
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| #include "mbedtls/platform.h"
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| 
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| /* Parameter validation macros based on platform_util.h */
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| #define PK_VALIDATE_RET(cond)    \
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|     MBEDTLS_INTERNAL_VALIDATE_RET(cond, MBEDTLS_ERR_PK_BAD_INPUT_DATA)
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| #define PK_VALIDATE(cond)        \
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|     MBEDTLS_INTERNAL_VALIDATE(cond)
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| 
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| #if defined(MBEDTLS_RSA_C)
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| /*
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|  *  RSAPublicKey ::= SEQUENCE {
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|  *      modulus           INTEGER,  -- n
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|  *      publicExponent    INTEGER   -- e
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|  *  }
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|  */
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| static int pk_write_rsa_pubkey(unsigned char **p, unsigned char *start,
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|                                mbedtls_rsa_context *rsa)
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| {
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|     int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
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|     size_t len = 0;
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|     mbedtls_mpi T;
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| 
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|     mbedtls_mpi_init(&T);
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| 
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|     /* Export E */
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|     if ((ret = mbedtls_rsa_export(rsa, NULL, NULL, NULL, NULL, &T)) != 0 ||
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|         (ret = mbedtls_asn1_write_mpi(p, start, &T)) < 0) {
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|         goto end_of_export;
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|     }
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|     len += ret;
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| 
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|     /* Export N */
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|     if ((ret = mbedtls_rsa_export(rsa, &T, NULL, NULL, NULL, NULL)) != 0 ||
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|         (ret = mbedtls_asn1_write_mpi(p, start, &T)) < 0) {
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|         goto end_of_export;
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|     }
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|     len += ret;
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| 
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| end_of_export:
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| 
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|     mbedtls_mpi_free(&T);
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|     if (ret < 0) {
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|         return ret;
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|     }
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| 
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|     MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_len(p, start, len));
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|     MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_tag(p, start, MBEDTLS_ASN1_CONSTRUCTED |
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|                                                      MBEDTLS_ASN1_SEQUENCE));
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| 
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|     return (int) len;
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| }
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| #endif /* MBEDTLS_RSA_C */
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| 
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| #if defined(MBEDTLS_ECP_C)
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| /*
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|  * EC public key is an EC point
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|  */
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| static int pk_write_ec_pubkey(unsigned char **p, unsigned char *start,
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|                               mbedtls_ecp_keypair *ec)
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| {
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|     int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
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|     size_t len = 0;
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|     unsigned char buf[MBEDTLS_ECP_MAX_PT_LEN];
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| 
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|     if ((ret = mbedtls_ecp_point_write_binary(&ec->grp, &ec->Q,
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|                                               MBEDTLS_ECP_PF_UNCOMPRESSED,
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|                                               &len, buf, sizeof(buf))) != 0) {
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|         return ret;
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|     }
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| 
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|     if (*p < start || (size_t) (*p - start) < len) {
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|         return MBEDTLS_ERR_ASN1_BUF_TOO_SMALL;
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|     }
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| 
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|     *p -= len;
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|     memcpy(*p, buf, len);
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| 
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|     return (int) len;
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| }
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| 
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| /*
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|  * ECParameters ::= CHOICE {
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|  *   namedCurve         OBJECT IDENTIFIER
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|  * }
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|  */
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| static int pk_write_ec_param(unsigned char **p, unsigned char *start,
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|                              mbedtls_ecp_keypair *ec)
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| {
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|     int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
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|     size_t len = 0;
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|     const char *oid;
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|     size_t oid_len;
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| 
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|     if ((ret = mbedtls_oid_get_oid_by_ec_grp(ec->grp.id, &oid, &oid_len)) != 0) {
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|         return ret;
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|     }
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| 
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|     MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_oid(p, start, oid, oid_len));
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| 
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|     return (int) len;
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| }
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| 
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| /*
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|  * privateKey  OCTET STRING -- always of length ceil(log2(n)/8)
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|  */
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| static int pk_write_ec_private(unsigned char **p, unsigned char *start,
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|                                mbedtls_ecp_keypair *ec)
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| {
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|     int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
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|     size_t byte_length = (ec->grp.pbits + 7) / 8;
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|     unsigned char tmp[MBEDTLS_ECP_MAX_BYTES];
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| 
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|     ret = mbedtls_ecp_write_key(ec, tmp, byte_length);
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|     if (ret != 0) {
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|         goto exit;
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|     }
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|     ret = mbedtls_asn1_write_octet_string(p, start, tmp, byte_length);
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| 
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| exit:
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|     mbedtls_platform_zeroize(tmp, byte_length);
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|     return ret;
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| }
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| #endif /* MBEDTLS_ECP_C */
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| 
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| int mbedtls_pk_write_pubkey(unsigned char **p, unsigned char *start,
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|                             const mbedtls_pk_context *key)
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| {
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|     int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
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|     size_t len = 0;
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| 
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|     PK_VALIDATE_RET(p != NULL);
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|     PK_VALIDATE_RET(*p != NULL);
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|     PK_VALIDATE_RET(start != NULL);
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|     PK_VALIDATE_RET(key != NULL);
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| 
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| #if defined(MBEDTLS_RSA_C)
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|     if (mbedtls_pk_get_type(key) == MBEDTLS_PK_RSA) {
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|         MBEDTLS_ASN1_CHK_ADD(len, pk_write_rsa_pubkey(p, start, mbedtls_pk_rsa(*key)));
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|     } else
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| #endif
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| #if defined(MBEDTLS_ECP_C)
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|     if (mbedtls_pk_get_type(key) == MBEDTLS_PK_ECKEY) {
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|         MBEDTLS_ASN1_CHK_ADD(len, pk_write_ec_pubkey(p, start, mbedtls_pk_ec(*key)));
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|     } else
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| #endif
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| #if defined(MBEDTLS_USE_PSA_CRYPTO)
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|     if (mbedtls_pk_get_type(key) == MBEDTLS_PK_OPAQUE) {
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|         size_t buffer_size;
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|         psa_key_id_t *key_id = (psa_key_id_t *) key->pk_ctx;
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| 
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|         if (*p < start) {
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|             return MBEDTLS_ERR_PK_BAD_INPUT_DATA;
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|         }
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| 
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|         buffer_size = (size_t) (*p - start);
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|         if (psa_export_public_key(*key_id, start, buffer_size, &len)
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|             != PSA_SUCCESS) {
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|             return MBEDTLS_ERR_PK_BAD_INPUT_DATA;
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|         } else {
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|             *p -= len;
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|             memmove(*p, start, len);
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|         }
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|     } else
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| #endif /* MBEDTLS_USE_PSA_CRYPTO */
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|     return MBEDTLS_ERR_PK_FEATURE_UNAVAILABLE;
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| 
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|     return (int) len;
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| }
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| 
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| int mbedtls_pk_write_pubkey_der(mbedtls_pk_context *key, unsigned char *buf, size_t size)
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| {
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|     int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
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|     unsigned char *c;
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|     size_t len = 0, par_len = 0, oid_len;
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|     mbedtls_pk_type_t pk_type;
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|     const char *oid;
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| 
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|     PK_VALIDATE_RET(key != NULL);
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|     if (size == 0) {
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|         return MBEDTLS_ERR_ASN1_BUF_TOO_SMALL;
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|     }
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|     PK_VALIDATE_RET(buf != NULL);
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| 
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|     c = buf + size;
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| 
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|     MBEDTLS_ASN1_CHK_ADD(len, mbedtls_pk_write_pubkey(&c, buf, key));
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| 
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|     if (c - buf < 1) {
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|         return MBEDTLS_ERR_ASN1_BUF_TOO_SMALL;
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|     }
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| 
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|     /*
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|      *  SubjectPublicKeyInfo  ::=  SEQUENCE  {
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|      *       algorithm            AlgorithmIdentifier,
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|      *       subjectPublicKey     BIT STRING }
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|      */
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|     *--c = 0;
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|     len += 1;
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| 
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|     MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_len(&c, buf, len));
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|     MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_tag(&c, buf, MBEDTLS_ASN1_BIT_STRING));
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| 
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|     pk_type = mbedtls_pk_get_type(key);
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| #if defined(MBEDTLS_ECP_C)
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|     if (pk_type == MBEDTLS_PK_ECKEY) {
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|         MBEDTLS_ASN1_CHK_ADD(par_len, pk_write_ec_param(&c, buf, mbedtls_pk_ec(*key)));
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|     }
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| #endif
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| #if defined(MBEDTLS_USE_PSA_CRYPTO)
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|     if (pk_type == MBEDTLS_PK_OPAQUE) {
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|         psa_key_attributes_t attributes = PSA_KEY_ATTRIBUTES_INIT;
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|         psa_key_type_t key_type;
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|         psa_key_id_t key_id;
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|         psa_ecc_family_t curve;
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|         size_t bits;
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| 
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|         key_id = *((psa_key_id_t *) key->pk_ctx);
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|         if (PSA_SUCCESS != psa_get_key_attributes(key_id, &attributes)) {
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|             return MBEDTLS_ERR_PK_HW_ACCEL_FAILED;
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|         }
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|         key_type = psa_get_key_type(&attributes);
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|         bits = psa_get_key_bits(&attributes);
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|         psa_reset_key_attributes(&attributes);
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| 
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|         curve = PSA_KEY_TYPE_ECC_GET_FAMILY(key_type);
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|         if (curve == 0) {
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|             return MBEDTLS_ERR_PK_FEATURE_UNAVAILABLE;
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|         }
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| 
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|         ret = mbedtls_psa_get_ecc_oid_from_id(curve, bits, &oid, &oid_len);
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|         if (ret != 0) {
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|             return MBEDTLS_ERR_PK_FEATURE_UNAVAILABLE;
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|         }
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| 
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|         /* Write EC algorithm parameters; that's akin
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|          * to pk_write_ec_param() above. */
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|         MBEDTLS_ASN1_CHK_ADD(par_len, mbedtls_asn1_write_oid(&c, buf,
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|                                                              oid, oid_len));
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| 
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|         /* The rest of the function works as for legacy EC contexts. */
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|         pk_type = MBEDTLS_PK_ECKEY;
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|     }
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| #endif /* MBEDTLS_USE_PSA_CRYPTO */
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| 
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|     if ((ret = mbedtls_oid_get_oid_by_pk_alg(pk_type, &oid,
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|                                              &oid_len)) != 0) {
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|         return ret;
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|     }
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| 
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|     MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_algorithm_identifier(&c, buf, oid, oid_len,
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|                                                                       par_len));
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| 
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|     MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_len(&c, buf, len));
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|     MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_tag(&c, buf, MBEDTLS_ASN1_CONSTRUCTED |
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|                                                      MBEDTLS_ASN1_SEQUENCE));
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| 
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|     return (int) len;
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| }
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| 
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| int mbedtls_pk_write_key_der(mbedtls_pk_context *key, unsigned char *buf, size_t size)
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| {
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|     int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
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|     unsigned char *c;
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|     size_t len = 0;
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| 
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|     PK_VALIDATE_RET(key != NULL);
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|     if (size == 0) {
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|         return MBEDTLS_ERR_ASN1_BUF_TOO_SMALL;
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|     }
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|     PK_VALIDATE_RET(buf != NULL);
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| 
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|     c = buf + size;
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| 
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| #if defined(MBEDTLS_RSA_C)
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|     if (mbedtls_pk_get_type(key) == MBEDTLS_PK_RSA) {
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|         mbedtls_mpi T; /* Temporary holding the exported parameters */
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|         mbedtls_rsa_context *rsa = mbedtls_pk_rsa(*key);
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| 
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|         /*
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|          * Export the parameters one after another to avoid simultaneous copies.
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|          */
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| 
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|         mbedtls_mpi_init(&T);
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| 
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|         /* Export QP */
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|         if ((ret = mbedtls_rsa_export_crt(rsa, NULL, NULL, &T)) != 0 ||
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|             (ret = mbedtls_asn1_write_mpi(&c, buf, &T)) < 0) {
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|             goto end_of_export;
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|         }
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|         len += ret;
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| 
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|         /* Export DQ */
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|         if ((ret = mbedtls_rsa_export_crt(rsa, NULL, &T, NULL)) != 0 ||
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|             (ret = mbedtls_asn1_write_mpi(&c, buf, &T)) < 0) {
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|             goto end_of_export;
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|         }
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|         len += ret;
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| 
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|         /* Export DP */
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|         if ((ret = mbedtls_rsa_export_crt(rsa, &T, NULL, NULL)) != 0 ||
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|             (ret = mbedtls_asn1_write_mpi(&c, buf, &T)) < 0) {
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|             goto end_of_export;
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|         }
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|         len += ret;
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| 
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|         /* Export Q */
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|         if ((ret = mbedtls_rsa_export(rsa, NULL, NULL,
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|                                       &T, NULL, NULL)) != 0 ||
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|             (ret = mbedtls_asn1_write_mpi(&c, buf, &T)) < 0) {
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|             goto end_of_export;
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|         }
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|         len += ret;
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| 
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|         /* Export P */
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|         if ((ret = mbedtls_rsa_export(rsa, NULL, &T,
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|                                       NULL, NULL, NULL)) != 0 ||
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|             (ret = mbedtls_asn1_write_mpi(&c, buf, &T)) < 0) {
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|             goto end_of_export;
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|         }
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|         len += ret;
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| 
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|         /* Export D */
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|         if ((ret = mbedtls_rsa_export(rsa, NULL, NULL,
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|                                       NULL, &T, NULL)) != 0 ||
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|             (ret = mbedtls_asn1_write_mpi(&c, buf, &T)) < 0) {
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|             goto end_of_export;
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|         }
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|         len += ret;
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| 
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|         /* Export E */
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|         if ((ret = mbedtls_rsa_export(rsa, NULL, NULL,
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|                                       NULL, NULL, &T)) != 0 ||
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|             (ret = mbedtls_asn1_write_mpi(&c, buf, &T)) < 0) {
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|             goto end_of_export;
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|         }
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|         len += ret;
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| 
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|         /* Export N */
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|         if ((ret = mbedtls_rsa_export(rsa, &T, NULL,
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|                                       NULL, NULL, NULL)) != 0 ||
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|             (ret = mbedtls_asn1_write_mpi(&c, buf, &T)) < 0) {
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|             goto end_of_export;
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|         }
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|         len += ret;
 | |
| 
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| end_of_export:
 | |
| 
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|         mbedtls_mpi_free(&T);
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|         if (ret < 0) {
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|             return ret;
 | |
|         }
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| 
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|         MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_int(&c, buf, 0));
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|         MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_len(&c, buf, len));
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|         MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_tag(&c,
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|                                                          buf, MBEDTLS_ASN1_CONSTRUCTED |
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|                                                          MBEDTLS_ASN1_SEQUENCE));
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|     } else
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| #endif /* MBEDTLS_RSA_C */
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| #if defined(MBEDTLS_ECP_C)
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|     if (mbedtls_pk_get_type(key) == MBEDTLS_PK_ECKEY) {
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|         mbedtls_ecp_keypair *ec = mbedtls_pk_ec(*key);
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|         size_t pub_len = 0, par_len = 0;
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| 
 | |
|         /*
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|          * RFC 5915, or SEC1 Appendix C.4
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|          *
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|          * ECPrivateKey ::= SEQUENCE {
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|          *      version        INTEGER { ecPrivkeyVer1(1) } (ecPrivkeyVer1),
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|          *      privateKey     OCTET STRING,
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|          *      parameters [0] ECParameters {{ NamedCurve }} OPTIONAL,
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|          *      publicKey  [1] BIT STRING OPTIONAL
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|          *    }
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|          */
 | |
| 
 | |
|         /* publicKey */
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|         MBEDTLS_ASN1_CHK_ADD(pub_len, pk_write_ec_pubkey(&c, buf, ec));
 | |
| 
 | |
|         if (c - buf < 1) {
 | |
|             return MBEDTLS_ERR_ASN1_BUF_TOO_SMALL;
 | |
|         }
 | |
|         *--c = 0;
 | |
|         pub_len += 1;
 | |
| 
 | |
|         MBEDTLS_ASN1_CHK_ADD(pub_len, mbedtls_asn1_write_len(&c, buf, pub_len));
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|         MBEDTLS_ASN1_CHK_ADD(pub_len, mbedtls_asn1_write_tag(&c, buf, MBEDTLS_ASN1_BIT_STRING));
 | |
| 
 | |
|         MBEDTLS_ASN1_CHK_ADD(pub_len, mbedtls_asn1_write_len(&c, buf, pub_len));
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|         MBEDTLS_ASN1_CHK_ADD(pub_len, mbedtls_asn1_write_tag(&c, buf,
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|                                                              MBEDTLS_ASN1_CONTEXT_SPECIFIC |
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|                                                              MBEDTLS_ASN1_CONSTRUCTED | 1));
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|         len += pub_len;
 | |
| 
 | |
|         /* parameters */
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|         MBEDTLS_ASN1_CHK_ADD(par_len, pk_write_ec_param(&c, buf, ec));
 | |
| 
 | |
|         MBEDTLS_ASN1_CHK_ADD(par_len, mbedtls_asn1_write_len(&c, buf, par_len));
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|         MBEDTLS_ASN1_CHK_ADD(par_len, mbedtls_asn1_write_tag(&c, buf,
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|                                                              MBEDTLS_ASN1_CONTEXT_SPECIFIC |
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|                                                              MBEDTLS_ASN1_CONSTRUCTED | 0));
 | |
|         len += par_len;
 | |
| 
 | |
|         /* privateKey */
 | |
|         MBEDTLS_ASN1_CHK_ADD(len, pk_write_ec_private(&c, buf, ec));
 | |
| 
 | |
|         /* version */
 | |
|         MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_int(&c, buf, 1));
 | |
| 
 | |
|         MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_len(&c, buf, len));
 | |
|         MBEDTLS_ASN1_CHK_ADD(len, mbedtls_asn1_write_tag(&c, buf, MBEDTLS_ASN1_CONSTRUCTED |
 | |
|                                                          MBEDTLS_ASN1_SEQUENCE));
 | |
|     } else
 | |
| #endif /* MBEDTLS_ECP_C */
 | |
|     return MBEDTLS_ERR_PK_FEATURE_UNAVAILABLE;
 | |
| 
 | |
|     return (int) len;
 | |
| }
 | |
| 
 | |
| #if defined(MBEDTLS_PEM_WRITE_C)
 | |
| 
 | |
| #define PEM_BEGIN_PUBLIC_KEY    "-----BEGIN PUBLIC KEY-----\n"
 | |
| #define PEM_END_PUBLIC_KEY      "-----END PUBLIC KEY-----\n"
 | |
| 
 | |
| #define PEM_BEGIN_PRIVATE_KEY_RSA   "-----BEGIN RSA PRIVATE KEY-----\n"
 | |
| #define PEM_END_PRIVATE_KEY_RSA     "-----END RSA PRIVATE KEY-----\n"
 | |
| #define PEM_BEGIN_PRIVATE_KEY_EC    "-----BEGIN EC PRIVATE KEY-----\n"
 | |
| #define PEM_END_PRIVATE_KEY_EC      "-----END EC PRIVATE KEY-----\n"
 | |
| 
 | |
| /*
 | |
|  * Max sizes of key per types. Shown as tag + len (+ content).
 | |
|  */
 | |
| 
 | |
| #if defined(MBEDTLS_RSA_C)
 | |
| /*
 | |
|  * RSA public keys:
 | |
|  *  SubjectPublicKeyInfo  ::=  SEQUENCE  {          1 + 3
 | |
|  *       algorithm            AlgorithmIdentifier,  1 + 1 (sequence)
 | |
|  *                                                + 1 + 1 + 9 (rsa oid)
 | |
|  *                                                + 1 + 1 (params null)
 | |
|  *       subjectPublicKey     BIT STRING }          1 + 3 + (1 + below)
 | |
|  *  RSAPublicKey ::= SEQUENCE {                     1 + 3
 | |
|  *      modulus           INTEGER,  -- n            1 + 3 + MPI_MAX + 1
 | |
|  *      publicExponent    INTEGER   -- e            1 + 3 + MPI_MAX + 1
 | |
|  *  }
 | |
|  */
 | |
| #define RSA_PUB_DER_MAX_BYTES   (38 + 2 * MBEDTLS_MPI_MAX_SIZE)
 | |
| 
 | |
| /*
 | |
|  * RSA private keys:
 | |
|  *  RSAPrivateKey ::= SEQUENCE {                    1 + 3
 | |
|  *      version           Version,                  1 + 1 + 1
 | |
|  *      modulus           INTEGER,                  1 + 3 + MPI_MAX + 1
 | |
|  *      publicExponent    INTEGER,                  1 + 3 + MPI_MAX + 1
 | |
|  *      privateExponent   INTEGER,                  1 + 3 + MPI_MAX + 1
 | |
|  *      prime1            INTEGER,                  1 + 3 + MPI_MAX / 2 + 1
 | |
|  *      prime2            INTEGER,                  1 + 3 + MPI_MAX / 2 + 1
 | |
|  *      exponent1         INTEGER,                  1 + 3 + MPI_MAX / 2 + 1
 | |
|  *      exponent2         INTEGER,                  1 + 3 + MPI_MAX / 2 + 1
 | |
|  *      coefficient       INTEGER,                  1 + 3 + MPI_MAX / 2 + 1
 | |
|  *      otherPrimeInfos   OtherPrimeInfos OPTIONAL  0 (not supported)
 | |
|  *  }
 | |
|  */
 | |
| #define MPI_MAX_SIZE_2          (MBEDTLS_MPI_MAX_SIZE / 2 + \
 | |
|                                  MBEDTLS_MPI_MAX_SIZE % 2)
 | |
| #define RSA_PRV_DER_MAX_BYTES   (47 + 3 * MBEDTLS_MPI_MAX_SIZE \
 | |
|                                  + 5 * MPI_MAX_SIZE_2)
 | |
| 
 | |
| #else /* MBEDTLS_RSA_C */
 | |
| 
 | |
| #define RSA_PUB_DER_MAX_BYTES   0
 | |
| #define RSA_PRV_DER_MAX_BYTES   0
 | |
| 
 | |
| #endif /* MBEDTLS_RSA_C */
 | |
| 
 | |
| #if defined(MBEDTLS_ECP_C)
 | |
| /*
 | |
|  * EC public keys:
 | |
|  *  SubjectPublicKeyInfo  ::=  SEQUENCE  {      1 + 2
 | |
|  *    algorithm         AlgorithmIdentifier,    1 + 1 (sequence)
 | |
|  *                                            + 1 + 1 + 7 (ec oid)
 | |
|  *                                            + 1 + 1 + 9 (namedCurve oid)
 | |
|  *    subjectPublicKey  BIT STRING              1 + 2 + 1               [1]
 | |
|  *                                            + 1 (point format)        [1]
 | |
|  *                                            + 2 * ECP_MAX (coords)    [1]
 | |
|  *  }
 | |
|  */
 | |
| #define ECP_PUB_DER_MAX_BYTES   (30 + 2 * MBEDTLS_ECP_MAX_BYTES)
 | |
| 
 | |
| /*
 | |
|  * EC private keys:
 | |
|  * ECPrivateKey ::= SEQUENCE {                  1 + 2
 | |
|  *      version        INTEGER ,                1 + 1 + 1
 | |
|  *      privateKey     OCTET STRING,            1 + 1 + ECP_MAX
 | |
|  *      parameters [0] ECParameters OPTIONAL,   1 + 1 + (1 + 1 + 9)
 | |
|  *      publicKey  [1] BIT STRING OPTIONAL      1 + 2 + [1] above
 | |
|  *    }
 | |
|  */
 | |
| #define ECP_PRV_DER_MAX_BYTES   (29 + 3 * MBEDTLS_ECP_MAX_BYTES)
 | |
| 
 | |
| #else /* MBEDTLS_ECP_C */
 | |
| 
 | |
| #define ECP_PUB_DER_MAX_BYTES   0
 | |
| #define ECP_PRV_DER_MAX_BYTES   0
 | |
| 
 | |
| #endif /* MBEDTLS_ECP_C */
 | |
| 
 | |
| #define PUB_DER_MAX_BYTES   (RSA_PUB_DER_MAX_BYTES > ECP_PUB_DER_MAX_BYTES ? \
 | |
|                              RSA_PUB_DER_MAX_BYTES : ECP_PUB_DER_MAX_BYTES)
 | |
| #define PRV_DER_MAX_BYTES   (RSA_PRV_DER_MAX_BYTES > ECP_PRV_DER_MAX_BYTES ? \
 | |
|                              RSA_PRV_DER_MAX_BYTES : ECP_PRV_DER_MAX_BYTES)
 | |
| 
 | |
| int mbedtls_pk_write_pubkey_pem(mbedtls_pk_context *key, unsigned char *buf, size_t size)
 | |
| {
 | |
|     int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
 | |
|     unsigned char output_buf[PUB_DER_MAX_BYTES];
 | |
|     size_t olen = 0;
 | |
| 
 | |
|     PK_VALIDATE_RET(key != NULL);
 | |
|     PK_VALIDATE_RET(buf != NULL || size == 0);
 | |
| 
 | |
|     if ((ret = mbedtls_pk_write_pubkey_der(key, output_buf,
 | |
|                                            sizeof(output_buf))) < 0) {
 | |
|         return ret;
 | |
|     }
 | |
| 
 | |
|     if ((ret = mbedtls_pem_write_buffer(PEM_BEGIN_PUBLIC_KEY, PEM_END_PUBLIC_KEY,
 | |
|                                         output_buf + sizeof(output_buf) - ret,
 | |
|                                         ret, buf, size, &olen)) != 0) {
 | |
|         return ret;
 | |
|     }
 | |
| 
 | |
|     return 0;
 | |
| }
 | |
| 
 | |
| int mbedtls_pk_write_key_pem(mbedtls_pk_context *key, unsigned char *buf, size_t size)
 | |
| {
 | |
|     int ret = MBEDTLS_ERR_ERROR_CORRUPTION_DETECTED;
 | |
|     unsigned char output_buf[PRV_DER_MAX_BYTES];
 | |
|     const char *begin, *end;
 | |
|     size_t olen = 0;
 | |
| 
 | |
|     PK_VALIDATE_RET(key != NULL);
 | |
|     PK_VALIDATE_RET(buf != NULL || size == 0);
 | |
| 
 | |
|     if ((ret = mbedtls_pk_write_key_der(key, output_buf, sizeof(output_buf))) < 0) {
 | |
|         return ret;
 | |
|     }
 | |
| 
 | |
| #if defined(MBEDTLS_RSA_C)
 | |
|     if (mbedtls_pk_get_type(key) == MBEDTLS_PK_RSA) {
 | |
|         begin = PEM_BEGIN_PRIVATE_KEY_RSA;
 | |
|         end = PEM_END_PRIVATE_KEY_RSA;
 | |
|     } else
 | |
| #endif
 | |
| #if defined(MBEDTLS_ECP_C)
 | |
|     if (mbedtls_pk_get_type(key) == MBEDTLS_PK_ECKEY) {
 | |
|         begin = PEM_BEGIN_PRIVATE_KEY_EC;
 | |
|         end = PEM_END_PRIVATE_KEY_EC;
 | |
|     } else
 | |
| #endif
 | |
|     return MBEDTLS_ERR_PK_FEATURE_UNAVAILABLE;
 | |
| 
 | |
|     if ((ret = mbedtls_pem_write_buffer(begin, end,
 | |
|                                         output_buf + sizeof(output_buf) - ret,
 | |
|                                         ret, buf, size, &olen)) != 0) {
 | |
|         return ret;
 | |
|     }
 | |
| 
 | |
|     return 0;
 | |
| }
 | |
| #endif /* MBEDTLS_PEM_WRITE_C */
 | |
| 
 | |
| #endif /* MBEDTLS_PK_WRITE_C */
 |