yuezonghe | 824eb0c | 2024-06-27 02:32:26 -0700 | [diff] [blame^] | 1 | /* |
| 2 | * Copyright 2015-2016 The OpenSSL Project Authors. All Rights Reserved. |
| 3 | * |
| 4 | * Licensed under the OpenSSL license (the "License"). You may not use |
| 5 | * this file except in compliance with the License. You can obtain a copy |
| 6 | * in the file LICENSE in the source distribution or at |
| 7 | * https://www.openssl.org/source/license.html |
| 8 | */ |
| 9 | |
| 10 | #include <stddef.h> |
| 11 | #include <openssl/ct.h> |
| 12 | #include <openssl/evp.h> |
| 13 | #include <openssl/x509.h> |
| 14 | #include <openssl/x509v3.h> |
| 15 | #include <openssl/safestack.h> |
| 16 | |
| 17 | /* |
| 18 | * From RFC6962: opaque SerializedSCT<1..2^16-1>; struct { SerializedSCT |
| 19 | * sct_list <1..2^16-1>; } SignedCertificateTimestampList; |
| 20 | */ |
| 21 | # define MAX_SCT_SIZE 65535 |
| 22 | # define MAX_SCT_LIST_SIZE MAX_SCT_SIZE |
| 23 | |
| 24 | /* |
| 25 | * Macros to read and write integers in network-byte order. |
| 26 | */ |
| 27 | |
| 28 | #define n2s(c,s) ((s=(((unsigned int)((c)[0]))<< 8)| \ |
| 29 | (((unsigned int)((c)[1])) )),c+=2) |
| 30 | |
| 31 | #define s2n(s,c) ((c[0]=(unsigned char)(((s)>> 8)&0xff), \ |
| 32 | c[1]=(unsigned char)(((s) )&0xff)),c+=2) |
| 33 | |
| 34 | #define l2n3(l,c) ((c[0]=(unsigned char)(((l)>>16)&0xff), \ |
| 35 | c[1]=(unsigned char)(((l)>> 8)&0xff), \ |
| 36 | c[2]=(unsigned char)(((l) )&0xff)),c+=3) |
| 37 | |
| 38 | #define n2l8(c,l) (l =((uint64_t)(*((c)++)))<<56, \ |
| 39 | l|=((uint64_t)(*((c)++)))<<48, \ |
| 40 | l|=((uint64_t)(*((c)++)))<<40, \ |
| 41 | l|=((uint64_t)(*((c)++)))<<32, \ |
| 42 | l|=((uint64_t)(*((c)++)))<<24, \ |
| 43 | l|=((uint64_t)(*((c)++)))<<16, \ |
| 44 | l|=((uint64_t)(*((c)++)))<< 8, \ |
| 45 | l|=((uint64_t)(*((c)++)))) |
| 46 | |
| 47 | #define l2n8(l,c) (*((c)++)=(unsigned char)(((l)>>56)&0xff), \ |
| 48 | *((c)++)=(unsigned char)(((l)>>48)&0xff), \ |
| 49 | *((c)++)=(unsigned char)(((l)>>40)&0xff), \ |
| 50 | *((c)++)=(unsigned char)(((l)>>32)&0xff), \ |
| 51 | *((c)++)=(unsigned char)(((l)>>24)&0xff), \ |
| 52 | *((c)++)=(unsigned char)(((l)>>16)&0xff), \ |
| 53 | *((c)++)=(unsigned char)(((l)>> 8)&0xff), \ |
| 54 | *((c)++)=(unsigned char)(((l) )&0xff)) |
| 55 | |
| 56 | /* Signed Certificate Timestamp */ |
| 57 | struct sct_st { |
| 58 | sct_version_t version; |
| 59 | /* If version is not SCT_VERSION_V1, this contains the encoded SCT */ |
| 60 | unsigned char *sct; |
| 61 | size_t sct_len; |
| 62 | /* If version is SCT_VERSION_V1, fields below contain components of the SCT */ |
| 63 | unsigned char *log_id; |
| 64 | size_t log_id_len; |
| 65 | /* |
| 66 | * Note, we cannot distinguish between an unset timestamp, and one |
| 67 | * that is set to 0. However since CT didn't exist in 1970, no real |
| 68 | * SCT should ever be set as such. |
| 69 | */ |
| 70 | uint64_t timestamp; |
| 71 | unsigned char *ext; |
| 72 | size_t ext_len; |
| 73 | unsigned char hash_alg; |
| 74 | unsigned char sig_alg; |
| 75 | unsigned char *sig; |
| 76 | size_t sig_len; |
| 77 | /* Log entry type */ |
| 78 | ct_log_entry_type_t entry_type; |
| 79 | /* Where this SCT was found, e.g. certificate, OCSP response, etc. */ |
| 80 | sct_source_t source; |
| 81 | /* The result of the last attempt to validate this SCT. */ |
| 82 | sct_validation_status_t validation_status; |
| 83 | }; |
| 84 | |
| 85 | /* Miscellaneous data that is useful when verifying an SCT */ |
| 86 | struct sct_ctx_st { |
| 87 | /* Public key */ |
| 88 | EVP_PKEY *pkey; |
| 89 | /* Hash of public key */ |
| 90 | unsigned char *pkeyhash; |
| 91 | size_t pkeyhashlen; |
| 92 | /* For pre-certificate: issuer public key hash */ |
| 93 | unsigned char *ihash; |
| 94 | size_t ihashlen; |
| 95 | /* certificate encoding */ |
| 96 | unsigned char *certder; |
| 97 | size_t certderlen; |
| 98 | /* pre-certificate encoding */ |
| 99 | unsigned char *preder; |
| 100 | size_t prederlen; |
| 101 | /* milliseconds since epoch (to check that the SCT isn't from the future) */ |
| 102 | uint64_t epoch_time_in_ms; |
| 103 | }; |
| 104 | |
| 105 | /* Context when evaluating whether a Certificate Transparency policy is met */ |
| 106 | struct ct_policy_eval_ctx_st { |
| 107 | X509 *cert; |
| 108 | X509 *issuer; |
| 109 | CTLOG_STORE *log_store; |
| 110 | /* milliseconds since epoch (to check that SCTs aren't from the future) */ |
| 111 | uint64_t epoch_time_in_ms; |
| 112 | }; |
| 113 | |
| 114 | /* |
| 115 | * Creates a new context for verifying an SCT. |
| 116 | */ |
| 117 | SCT_CTX *SCT_CTX_new(void); |
| 118 | /* |
| 119 | * Deletes an SCT verification context. |
| 120 | */ |
| 121 | void SCT_CTX_free(SCT_CTX *sctx); |
| 122 | |
| 123 | /* |
| 124 | * Sets the certificate that the SCT was created for. |
| 125 | * If *cert does not have a poison extension, presigner must be NULL. |
| 126 | * If *cert does not have a poison extension, it may have a single SCT |
| 127 | * (NID_ct_precert_scts) extension. |
| 128 | * If either *cert or *presigner have an AKID (NID_authority_key_identifier) |
| 129 | * extension, both must have one. |
| 130 | * Returns 1 on success, 0 on failure. |
| 131 | */ |
| 132 | __owur int SCT_CTX_set1_cert(SCT_CTX *sctx, X509 *cert, X509 *presigner); |
| 133 | |
| 134 | /* |
| 135 | * Sets the issuer of the certificate that the SCT was created for. |
| 136 | * This is just a convenience method to save extracting the public key and |
| 137 | * calling SCT_CTX_set1_issuer_pubkey(). |
| 138 | * Issuer must not be NULL. |
| 139 | * Returns 1 on success, 0 on failure. |
| 140 | */ |
| 141 | __owur int SCT_CTX_set1_issuer(SCT_CTX *sctx, const X509 *issuer); |
| 142 | |
| 143 | /* |
| 144 | * Sets the public key of the issuer of the certificate that the SCT was created |
| 145 | * for. |
| 146 | * The public key must not be NULL. |
| 147 | * Returns 1 on success, 0 on failure. |
| 148 | */ |
| 149 | __owur int SCT_CTX_set1_issuer_pubkey(SCT_CTX *sctx, X509_PUBKEY *pubkey); |
| 150 | |
| 151 | /* |
| 152 | * Sets the public key of the CT log that the SCT is from. |
| 153 | * Returns 1 on success, 0 on failure. |
| 154 | */ |
| 155 | __owur int SCT_CTX_set1_pubkey(SCT_CTX *sctx, X509_PUBKEY *pubkey); |
| 156 | |
| 157 | /* |
| 158 | * Sets the time to evaluate the SCT against, in milliseconds since the Unix |
| 159 | * epoch. If the SCT's timestamp is after this time, it will be interpreted as |
| 160 | * having been issued in the future. RFC6962 states that "TLS clients MUST |
| 161 | * reject SCTs whose timestamp is in the future", so an SCT will not validate |
| 162 | * in this case. |
| 163 | */ |
| 164 | void SCT_CTX_set_time(SCT_CTX *sctx, uint64_t time_in_ms); |
| 165 | |
| 166 | /* |
| 167 | * Verifies an SCT with the given context. |
| 168 | * Returns 1 if the SCT verifies successfully; any other value indicates |
| 169 | * failure. See EVP_DigestVerifyFinal() for the meaning of those values. |
| 170 | */ |
| 171 | __owur int SCT_CTX_verify(const SCT_CTX *sctx, const SCT *sct); |
| 172 | |
| 173 | /* |
| 174 | * Does this SCT have the minimum fields populated to be usable? |
| 175 | * Returns 1 if so, 0 otherwise. |
| 176 | */ |
| 177 | __owur int SCT_is_complete(const SCT *sct); |
| 178 | |
| 179 | /* |
| 180 | * Does this SCT have the signature-related fields populated? |
| 181 | * Returns 1 if so, 0 otherwise. |
| 182 | * This checks that the signature and hash algorithms are set to supported |
| 183 | * values and that the signature field is set. |
| 184 | */ |
| 185 | __owur int SCT_signature_is_complete(const SCT *sct); |
| 186 | |
| 187 | /* |
| 188 | * TODO(RJPercival): Create an SCT_signature struct and make i2o_SCT_signature |
| 189 | * and o2i_SCT_signature conform to the i2d/d2i conventions. |
| 190 | */ |
| 191 | |
| 192 | /* |
| 193 | * Serialize (to TLS format) an |sct| signature and write it to |out|. |
| 194 | * If |out| is null, no signature will be output but the length will be returned. |
| 195 | * If |out| points to a null pointer, a string will be allocated to hold the |
| 196 | * TLS-format signature. It is the responsibility of the caller to free it. |
| 197 | * If |out| points to an allocated string, the signature will be written to it. |
| 198 | * The length of the signature in TLS format will be returned. |
| 199 | */ |
| 200 | __owur int i2o_SCT_signature(const SCT *sct, unsigned char **out); |
| 201 | |
| 202 | /* |
| 203 | * Parses an SCT signature in TLS format and populates the |sct| with it. |
| 204 | * |in| should be a pointer to a string containing the TLS-format signature. |
| 205 | * |in| will be advanced to the end of the signature if parsing succeeds. |
| 206 | * |len| should be the length of the signature in |in|. |
| 207 | * Returns the number of bytes parsed, or a negative integer if an error occurs. |
| 208 | * If an error occurs, the SCT's signature NID may be updated whilst the |
| 209 | * signature field itself remains unset. |
| 210 | */ |
| 211 | __owur int o2i_SCT_signature(SCT *sct, const unsigned char **in, size_t len); |
| 212 | |
| 213 | /* |
| 214 | * Handlers for Certificate Transparency X509v3/OCSP extensions |
| 215 | */ |
| 216 | extern const X509V3_EXT_METHOD v3_ct_scts[3]; |