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 OR GPL-2.0-or-later 10 */ 11 12 /** 13 * Note: For the time being, this implementation of the PKCS #7 cryptographic 14 * message syntax is a partial implementation of RFC 2315. 15 * Differences include: 16 * - The RFC specifies 6 different content types. The only type currently 17 * supported in Mbed TLS is the signed-data content type. 18 * - The only supported PKCS #7 Signed Data syntax version is version 1 19 * - The RFC specifies support for BER. This implementation is limited to 20 * DER only. 21 * - The RFC specifies that multiple digest algorithms can be specified 22 * in the Signed Data type. Only one digest algorithm is supported in Mbed TLS. 23 * - The RFC specifies the Signed Data type can contain multiple X.509 or PKCS #6 extended 24 * certificates. In Mbed TLS, this list can only contain 0 or 1 certificates 25 * and they must be in X.509 format. 26 * - The RFC specifies the Signed Data type can contain 27 * certificate-revocation lists (CRLs). This implementation has no support 28 * for CRLs so it is assumed to be an empty list. 29 * - The RFC allows for SignerInfo structure to optionally contain 30 * unauthenticatedAttributes and authenticatedAttributes. In Mbed TLS it is 31 * assumed these fields are empty. 32 * - The RFC allows for the signed Data type to contain contentInfo. This 33 * implementation assumes the type is DATA and the content is empty. 34 */ 35 36 #ifndef MBEDTLS_PKCS7_H 37 #define MBEDTLS_PKCS7_H 38 39 #include "mbedtls/private_access.h" 40 41 #include "mbedtls/build_info.h" 42 43 #include "mbedtls/asn1.h" 44 #include "mbedtls/x509_crt.h" 45 46 /** 47 * \name PKCS #7 Module Error codes 48 * \{ 49 */ 50 #define MBEDTLS_ERR_PKCS7_INVALID_FORMAT -0x5300 /**< The format is invalid, e.g. different type expected. */ 51 #define MBEDTLS_ERR_PKCS7_FEATURE_UNAVAILABLE -0x5380 /**< Unavailable feature, e.g. anything other than signed data. */ 52 #define MBEDTLS_ERR_PKCS7_INVALID_VERSION -0x5400 /**< The PKCS #7 version element is invalid or cannot be parsed. */ 53 #define MBEDTLS_ERR_PKCS7_INVALID_CONTENT_INFO -0x5480 /**< The PKCS #7 content info is invalid or cannot be parsed. */ 54 #define MBEDTLS_ERR_PKCS7_INVALID_ALG -0x5500 /**< The algorithm tag or value is invalid or cannot be parsed. */ 55 #define MBEDTLS_ERR_PKCS7_INVALID_CERT -0x5580 /**< The certificate tag or value is invalid or cannot be parsed. */ 56 #define MBEDTLS_ERR_PKCS7_INVALID_SIGNATURE -0x5600 /**< Error parsing the signature */ 57 #define MBEDTLS_ERR_PKCS7_INVALID_SIGNER_INFO -0x5680 /**< Error parsing the signer's info */ 58 #define MBEDTLS_ERR_PKCS7_BAD_INPUT_DATA -0x5700 /**< Input invalid. */ 59 #define MBEDTLS_ERR_PKCS7_ALLOC_FAILED -0x5780 /**< Allocation of memory failed. */ 60 #define MBEDTLS_ERR_PKCS7_VERIFY_FAIL -0x5800 /**< Verification Failed */ 61 #define MBEDTLS_ERR_PKCS7_CERT_DATE_INVALID -0x5880 /**< The PKCS #7 date issued/expired dates are invalid */ 62 /* \} name */ 63 64 /** 65 * \name PKCS #7 Supported Version 66 * \{ 67 */ 68 #define MBEDTLS_PKCS7_SUPPORTED_VERSION 0x01 69 /* \} name */ 70 71 #ifdef __cplusplus 72 extern "C" { 73 #endif 74 75 /** 76 * Type-length-value structure that allows for ASN.1 using DER. 77 */ 78 typedef mbedtls_asn1_buf mbedtls_pkcs7_buf; 79 80 /** 81 * Container for ASN.1 named information objects. 82 * It allows for Relative Distinguished Names (e.g. cn=localhost,ou=code,etc.). 83 */ 84 typedef mbedtls_asn1_named_data mbedtls_pkcs7_name; 85 86 /** 87 * Container for a sequence of ASN.1 items 88 */ 89 typedef mbedtls_asn1_sequence mbedtls_pkcs7_sequence; 90 91 /** 92 * PKCS #7 types 93 */ 94 typedef enum { 95 MBEDTLS_PKCS7_NONE=0, 96 MBEDTLS_PKCS7_DATA, 97 MBEDTLS_PKCS7_SIGNED_DATA, 98 MBEDTLS_PKCS7_ENVELOPED_DATA, 99 MBEDTLS_PKCS7_SIGNED_AND_ENVELOPED_DATA, 100 MBEDTLS_PKCS7_DIGESTED_DATA, 101 MBEDTLS_PKCS7_ENCRYPTED_DATA, 102 } 103 mbedtls_pkcs7_type; 104 105 /** 106 * Structure holding PKCS #7 signer info 107 */ 108 typedef struct mbedtls_pkcs7_signer_info { 109 int MBEDTLS_PRIVATE(version); 110 mbedtls_x509_buf MBEDTLS_PRIVATE(serial); 111 mbedtls_x509_name MBEDTLS_PRIVATE(issuer); 112 mbedtls_x509_buf MBEDTLS_PRIVATE(issuer_raw); 113 mbedtls_x509_buf MBEDTLS_PRIVATE(alg_identifier); 114 mbedtls_x509_buf MBEDTLS_PRIVATE(sig_alg_identifier); 115 mbedtls_x509_buf MBEDTLS_PRIVATE(sig); 116 struct mbedtls_pkcs7_signer_info *MBEDTLS_PRIVATE(next); 117 } 118 mbedtls_pkcs7_signer_info; 119 120 /** 121 * Structure holding the signed data section 122 */ 123 typedef struct mbedtls_pkcs7_signed_data { 124 int MBEDTLS_PRIVATE(version); 125 mbedtls_pkcs7_buf MBEDTLS_PRIVATE(digest_alg_identifiers); 126 int MBEDTLS_PRIVATE(no_of_certs); 127 mbedtls_x509_crt MBEDTLS_PRIVATE(certs); 128 int MBEDTLS_PRIVATE(no_of_crls); 129 mbedtls_x509_crl MBEDTLS_PRIVATE(crl); 130 int MBEDTLS_PRIVATE(no_of_signers); 131 mbedtls_pkcs7_signer_info MBEDTLS_PRIVATE(signers); 132 } 133 mbedtls_pkcs7_signed_data; 134 135 /** 136 * Structure holding PKCS #7 structure, only signed data for now 137 */ 138 typedef struct mbedtls_pkcs7 { 139 mbedtls_pkcs7_buf MBEDTLS_PRIVATE(raw); 140 mbedtls_pkcs7_signed_data MBEDTLS_PRIVATE(signed_data); 141 } 142 mbedtls_pkcs7; 143 144 /** 145 * \brief Initialize mbedtls_pkcs7 structure. 146 * 147 * \param pkcs7 mbedtls_pkcs7 structure. 148 */ 149 void mbedtls_pkcs7_init(mbedtls_pkcs7 *pkcs7); 150 151 /** 152 * \brief Parse a single DER formatted PKCS #7 detached signature. 153 * 154 * \param pkcs7 The mbedtls_pkcs7 structure to be filled by the parser. 155 * \param buf The buffer holding only the DER encoded PKCS #7 content. 156 * \param buflen The size in bytes of \p buf. The size must be exactly the 157 * length of the DER encoded PKCS #7 content. 158 * 159 * \note This function makes an internal copy of the PKCS #7 buffer 160 * \p buf. In particular, \p buf may be destroyed or reused 161 * after this call returns. 162 * \note Signatures with internal data are not supported. 163 * 164 * \return The \c mbedtls_pkcs7_type of \p buf, if successful. 165 * \return A negative error code on failure. 166 */ 167 int mbedtls_pkcs7_parse_der(mbedtls_pkcs7 *pkcs7, const unsigned char *buf, 168 const size_t buflen); 169 170 /** 171 * \brief Verification of PKCS #7 signature against a caller-supplied 172 * certificate. 173 * 174 * For each signer in the PKCS structure, this function computes 175 * a signature over the supplied data, using the supplied 176 * certificate and the same digest algorithm as specified by the 177 * signer. It then compares this signature against the 178 * signer's signature; verification succeeds if any comparison 179 * matches. 180 * 181 * This function does not use the certificates held within the 182 * PKCS #7 structure itself, and does not check that the 183 * certificate is signed by a trusted certification authority. 184 * 185 * \param pkcs7 mbedtls_pkcs7 structure containing signature. 186 * \param cert Certificate containing key to verify signature. 187 * \param data Plain data on which signature has to be verified. 188 * \param datalen Length of the data. 189 * 190 * \note This function internally calculates the hash on the supplied 191 * plain data for signature verification. 192 * 193 * \return 0 if the signature verifies, or a negative error code on failure. 194 */ 195 int mbedtls_pkcs7_signed_data_verify(mbedtls_pkcs7 *pkcs7, 196 const mbedtls_x509_crt *cert, 197 const unsigned char *data, 198 size_t datalen); 199 200 /** 201 * \brief Verification of PKCS #7 signature against a caller-supplied 202 * certificate. 203 * 204 * For each signer in the PKCS structure, this function 205 * validates a signature over the supplied hash, using the 206 * supplied certificate and the same digest algorithm as 207 * specified by the signer. Verification succeeds if any 208 * signature is good. 209 * 210 * This function does not use the certificates held within the 211 * PKCS #7 structure itself, and does not check that the 212 * certificate is signed by a trusted certification authority. 213 * 214 * \param pkcs7 PKCS #7 structure containing signature. 215 * \param cert Certificate containing key to verify signature. 216 * \param hash Hash of the plain data on which signature has to be verified. 217 * \param hashlen Length of the hash. 218 * 219 * \note This function is different from mbedtls_pkcs7_signed_data_verify() 220 * in that it is directly passed the hash of the data. 221 * 222 * \return 0 if the signature verifies, or a negative error code on failure. 223 */ 224 int mbedtls_pkcs7_signed_hash_verify(mbedtls_pkcs7 *pkcs7, 225 const mbedtls_x509_crt *cert, 226 const unsigned char *hash, size_t hashlen); 227 228 /** 229 * \brief Unallocate all PKCS #7 data and zeroize the memory. 230 * It doesn't free \p pkcs7 itself. This should be done by the caller. 231 * 232 * \param pkcs7 mbedtls_pkcs7 structure to free. 233 */ 234 void mbedtls_pkcs7_free(mbedtls_pkcs7 *pkcs7); 235 236 #ifdef __cplusplus 237 } 238 #endif 239 240 #endif /* pkcs7.h */ 241
