1 /** 2 * \file pkcs7.h 3 * 4 * \brief PKCS #7 generic defines and structures 5 * https://tools.ietf.org/html/rfc2315 6 */ 7 /* 8 * Copyright The Mbed TLS Contributors 9 * SPDX-License-Identifier: Apache-2.0 10 * 11 * Licensed under the Apache License, Version 2.0 (the "License"); you may 12 * not use this file except in compliance with the License. 13 * You may obtain a copy of the License at 14 * 15 * http://www.apache.org/licenses/LICENSE-2.0 16 * 17 * Unless required by applicable law or agreed to in writing, software 18 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT 19 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 20 * See the License for the specific language governing permissions and 21 * limitations under the License. 22 */ 23 24 /** 25 * Note: For the time being, this implementation of the PKCS #7 cryptographic 26 * message syntax is a partial implementation of RFC 2315. 27 * Differences include: 28 * - The RFC specifies 6 different content types. The only type currently 29 * supported in Mbed TLS is the signed-data content type. 30 * - The only supported PKCS #7 Signed Data syntax version is version 1 31 * - The RFC specifies support for BER. This implementation is limited to 32 * DER only. 33 * - The RFC specifies that multiple digest algorithms can be specified 34 * in the Signed Data type. Only one digest algorithm is supported in Mbed TLS. 35 * - The RFC specifies the Signed Data type can contain multiple X.509 or PKCS #6 extended 36 * certificates. In Mbed TLS, this list can only contain 0 or 1 certificates 37 * and they must be in X.509 format. 38 * - The RFC specifies the Signed Data type can contain 39 * certificate-revocation lists (CRLs). This implementation has no support 40 * for CRLs so it is assumed to be an empty list. 41 * - The RFC allows for SignerInfo structure to optionally contain 42 * unauthenticatedAttributes and authenticatedAttributes. In Mbed TLS it is 43 * assumed these fields are empty. 44 * - The RFC allows for the signed Data type to contain contentInfo. This 45 * implementation assumes the type is DATA and the content is empty. 46 */ 47 48 #ifndef MBEDTLS_PKCS7_H 49 #define MBEDTLS_PKCS7_H 50 51 #include "mbedtls/private_access.h" 52 53 #include "mbedtls/build_info.h" 54 55 #include "mbedtls/asn1.h" 56 #include "mbedtls/x509.h" 57 #include "mbedtls/x509_crt.h" 58 59 /** 60 * \name PKCS #7 Module Error codes 61 * \{ 62 */ 63 #define MBEDTLS_ERR_PKCS7_INVALID_FORMAT -0x5300 /**< The format is invalid, e.g. different type expected. */ 64 #define MBEDTLS_ERR_PKCS7_FEATURE_UNAVAILABLE -0x5380 /**< Unavailable feature, e.g. anything other than signed data. */ 65 #define MBEDTLS_ERR_PKCS7_INVALID_VERSION -0x5400 /**< The PKCS #7 version element is invalid or cannot be parsed. */ 66 #define MBEDTLS_ERR_PKCS7_INVALID_CONTENT_INFO -0x5480 /**< The PKCS #7 content info is invalid or cannot be parsed. */ 67 #define MBEDTLS_ERR_PKCS7_INVALID_ALG -0x5500 /**< The algorithm tag or value is invalid or cannot be parsed. */ 68 #define MBEDTLS_ERR_PKCS7_INVALID_CERT -0x5580 /**< The certificate tag or value is invalid or cannot be parsed. */ 69 #define MBEDTLS_ERR_PKCS7_INVALID_SIGNATURE -0x5600 /**< Error parsing the signature */ 70 #define MBEDTLS_ERR_PKCS7_INVALID_SIGNER_INFO -0x5680 /**< Error parsing the signer's info */ 71 #define MBEDTLS_ERR_PKCS7_BAD_INPUT_DATA -0x5700 /**< Input invalid. */ 72 #define MBEDTLS_ERR_PKCS7_ALLOC_FAILED -0x5780 /**< Allocation of memory failed. */ 73 #define MBEDTLS_ERR_PKCS7_VERIFY_FAIL -0x5800 /**< Verification Failed */ 74 #define MBEDTLS_ERR_PKCS7_CERT_DATE_INVALID -0x5880 /**< The PKCS #7 date issued/expired dates are invalid */ 75 /* \} name */ 76 77 /** 78 * \name PKCS #7 Supported Version 79 * \{ 80 */ 81 #define MBEDTLS_PKCS7_SUPPORTED_VERSION 0x01 82 /* \} name */ 83 84 #ifdef __cplusplus 85 extern "C" { 86 #endif 87 88 /** 89 * Type-length-value structure that allows for ASN.1 using DER. 90 */ 91 typedef mbedtls_asn1_buf mbedtls_pkcs7_buf; 92 93 /** 94 * Container for ASN.1 named information objects. 95 * It allows for Relative Distinguished Names (e.g. cn=localhost,ou=code,etc.). 96 */ 97 typedef mbedtls_asn1_named_data mbedtls_pkcs7_name; 98 99 /** 100 * Container for a sequence of ASN.1 items 101 */ 102 typedef mbedtls_asn1_sequence mbedtls_pkcs7_sequence; 103 104 /** 105 * PKCS #7 types 106 */ 107 typedef enum { 108 MBEDTLS_PKCS7_NONE=0, 109 MBEDTLS_PKCS7_DATA, 110 MBEDTLS_PKCS7_SIGNED_DATA, 111 MBEDTLS_PKCS7_ENVELOPED_DATA, 112 MBEDTLS_PKCS7_SIGNED_AND_ENVELOPED_DATA, 113 MBEDTLS_PKCS7_DIGESTED_DATA, 114 MBEDTLS_PKCS7_ENCRYPTED_DATA, 115 } 116 mbedtls_pkcs7_type; 117 118 /** 119 * Structure holding PKCS #7 signer info 120 */ 121 typedef struct mbedtls_pkcs7_signer_info { 122 int MBEDTLS_PRIVATE(version); 123 mbedtls_x509_buf MBEDTLS_PRIVATE(serial); 124 mbedtls_x509_name MBEDTLS_PRIVATE(issuer); 125 mbedtls_x509_buf MBEDTLS_PRIVATE(issuer_raw); 126 mbedtls_x509_buf MBEDTLS_PRIVATE(alg_identifier); 127 mbedtls_x509_buf MBEDTLS_PRIVATE(sig_alg_identifier); 128 mbedtls_x509_buf MBEDTLS_PRIVATE(sig); 129 struct mbedtls_pkcs7_signer_info *MBEDTLS_PRIVATE(next); 130 } 131 mbedtls_pkcs7_signer_info; 132 133 /** 134 * Structure holding the signed data section 135 */ 136 typedef struct mbedtls_pkcs7_signed_data { 137 int MBEDTLS_PRIVATE(version); 138 mbedtls_pkcs7_buf MBEDTLS_PRIVATE(digest_alg_identifiers); 139 int MBEDTLS_PRIVATE(no_of_certs); 140 mbedtls_x509_crt MBEDTLS_PRIVATE(certs); 141 int MBEDTLS_PRIVATE(no_of_crls); 142 mbedtls_x509_crl MBEDTLS_PRIVATE(crl); 143 int MBEDTLS_PRIVATE(no_of_signers); 144 mbedtls_pkcs7_signer_info MBEDTLS_PRIVATE(signers); 145 } 146 mbedtls_pkcs7_signed_data; 147 148 /** 149 * Structure holding PKCS #7 structure, only signed data for now 150 */ 151 typedef struct mbedtls_pkcs7 { 152 mbedtls_pkcs7_buf MBEDTLS_PRIVATE(raw); 153 mbedtls_pkcs7_signed_data MBEDTLS_PRIVATE(signed_data); 154 } 155 mbedtls_pkcs7; 156 157 /** 158 * \brief Initialize mbedtls_pkcs7 structure. 159 * 160 * \param pkcs7 mbedtls_pkcs7 structure. 161 */ 162 void mbedtls_pkcs7_init(mbedtls_pkcs7 *pkcs7); 163 164 /** 165 * \brief Parse a single DER formatted PKCS #7 detached signature. 166 * 167 * \param pkcs7 The mbedtls_pkcs7 structure to be filled by the parser. 168 * \param buf The buffer holding only the DER encoded PKCS #7 content. 169 * \param buflen The size in bytes of \p buf. The size must be exactly the 170 * length of the DER encoded PKCS #7 content. 171 * 172 * \note This function makes an internal copy of the PKCS #7 buffer 173 * \p buf. In particular, \p buf may be destroyed or reused 174 * after this call returns. 175 * \note Signatures with internal data are not supported. 176 * 177 * \return The \c mbedtls_pkcs7_type of \p buf, if successful. 178 * \return A negative error code on failure. 179 */ 180 int mbedtls_pkcs7_parse_der(mbedtls_pkcs7 *pkcs7, const unsigned char *buf, 181 const size_t buflen); 182 183 /** 184 * \brief Verification of PKCS #7 signature against a caller-supplied 185 * certificate. 186 * 187 * For each signer in the PKCS structure, this function computes 188 * a signature over the supplied data, using the supplied 189 * certificate and the same digest algorithm as specified by the 190 * signer. It then compares this signature against the 191 * signer's signature; verification succeeds if any comparison 192 * matches. 193 * 194 * This function does not use the certificates held within the 195 * PKCS #7 structure itself, and does not check that the 196 * certificate is signed by a trusted certification authority. 197 * 198 * \param pkcs7 mbedtls_pkcs7 structure containing signature. 199 * \param cert Certificate containing key to verify signature. 200 * \param data Plain data on which signature has to be verified. 201 * \param datalen Length of the data. 202 * 203 * \note This function internally calculates the hash on the supplied 204 * plain data for signature verification. 205 * 206 * \return 0 if the signature verifies, or a negative error code on failure. 207 */ 208 int mbedtls_pkcs7_signed_data_verify(mbedtls_pkcs7 *pkcs7, 209 const mbedtls_x509_crt *cert, 210 const unsigned char *data, 211 size_t datalen); 212 213 /** 214 * \brief Verification of PKCS #7 signature against a caller-supplied 215 * certificate. 216 * 217 * For each signer in the PKCS structure, this function 218 * validates a signature over the supplied hash, using the 219 * supplied certificate and the same digest algorithm as 220 * specified by the signer. Verification succeeds if any 221 * signature is good. 222 * 223 * This function does not use the certificates held within the 224 * PKCS #7 structure itself, and does not check that the 225 * certificate is signed by a trusted certification authority. 226 * 227 * \param pkcs7 PKCS #7 structure containing signature. 228 * \param cert Certificate containing key to verify signature. 229 * \param hash Hash of the plain data on which signature has to be verified. 230 * \param hashlen Length of the hash. 231 * 232 * \note This function is different from mbedtls_pkcs7_signed_data_verify() 233 * in that it is directly passed the hash of the data. 234 * 235 * \return 0 if the signature verifies, or a negative error code on failure. 236 */ 237 int mbedtls_pkcs7_signed_hash_verify(mbedtls_pkcs7 *pkcs7, 238 const mbedtls_x509_crt *cert, 239 const unsigned char *hash, size_t hashlen); 240 241 /** 242 * \brief Unallocate all PKCS #7 data and zeroize the memory. 243 * It doesn't free \p pkcs7 itself. This should be done by the caller. 244 * 245 * \param pkcs7 mbedtls_pkcs7 structure to free. 246 */ 247 void mbedtls_pkcs7_free(mbedtls_pkcs7 *pkcs7); 248 249 #ifdef __cplusplus 250 } 251 #endif 252 253 #endif /* pkcs7.h */ 254