1=pod 2 3=head1 NAME 4 5SCT_new, SCT_new_from_base64, SCT_free, SCT_LIST_free, 6SCT_get_version, SCT_set_version, 7SCT_get_log_entry_type, SCT_set_log_entry_type, 8SCT_get0_log_id, SCT_set0_log_id, SCT_set1_log_id, 9SCT_get_timestamp, SCT_set_timestamp, 10SCT_get_signature_nid, SCT_set_signature_nid, 11SCT_get0_signature, SCT_set0_signature, SCT_set1_signature, 12SCT_get0_extensions, SCT_set0_extensions, SCT_set1_extensions, 13SCT_get_source, SCT_set_source 14- A Certificate Transparency Signed Certificate Timestamp 15 16=head1 SYNOPSIS 17 18 #include <openssl/ct.h> 19 20 typedef enum { 21 CT_LOG_ENTRY_TYPE_NOT_SET = -1, 22 CT_LOG_ENTRY_TYPE_X509 = 0, 23 CT_LOG_ENTRY_TYPE_PRECERT = 1 24 } ct_log_entry_type_t; 25 26 typedef enum { 27 SCT_VERSION_NOT_SET = -1, 28 SCT_VERSION_V1 = 0 29 } sct_version_t; 30 31 typedef enum { 32 SCT_SOURCE_UNKNOWN, 33 SCT_SOURCE_TLS_EXTENSION, 34 SCT_SOURCE_X509V3_EXTENSION, 35 SCT_SOURCE_OCSP_STAPLED_RESPONSE 36 } sct_source_t; 37 38 SCT *SCT_new(void); 39 SCT *SCT_new_from_base64(unsigned char version, 40 const char *logid_base64, 41 ct_log_entry_type_t entry_type, 42 uint64_t timestamp, 43 const char *extensions_base64, 44 const char *signature_base64); 45 46 void SCT_free(SCT *sct); 47 void SCT_LIST_free(STACK_OF(SCT) *a); 48 49 sct_version_t SCT_get_version(const SCT *sct); 50 int SCT_set_version(SCT *sct, sct_version_t version); 51 52 ct_log_entry_type_t SCT_get_log_entry_type(const SCT *sct); 53 int SCT_set_log_entry_type(SCT *sct, ct_log_entry_type_t entry_type); 54 55 size_t SCT_get0_log_id(const SCT *sct, unsigned char **log_id); 56 int SCT_set0_log_id(SCT *sct, unsigned char *log_id, size_t log_id_len); 57 int SCT_set1_log_id(SCT *sct, const unsigned char *log_id, size_t log_id_len); 58 59 uint64_t SCT_get_timestamp(const SCT *sct); 60 void SCT_set_timestamp(SCT *sct, uint64_t timestamp); 61 62 int SCT_get_signature_nid(const SCT *sct); 63 int SCT_set_signature_nid(SCT *sct, int nid); 64 65 size_t SCT_get0_signature(const SCT *sct, unsigned char **sig); 66 void SCT_set0_signature(SCT *sct, unsigned char *sig, size_t sig_len); 67 int SCT_set1_signature(SCT *sct, const unsigned char *sig, size_t sig_len); 68 69 size_t SCT_get0_extensions(const SCT *sct, unsigned char **ext); 70 void SCT_set0_extensions(SCT *sct, unsigned char *ext, size_t ext_len); 71 int SCT_set1_extensions(SCT *sct, const unsigned char *ext, size_t ext_len); 72 73 sct_source_t SCT_get_source(const SCT *sct); 74 int SCT_set_source(SCT *sct, sct_source_t source); 75 76=head1 DESCRIPTION 77 78Signed Certificate Timestamps (SCTs) are defined by RFC 6962, Section 3.2. 79They constitute a promise by a Certificate Transparency (CT) log to publicly 80record a certificate. By cryptographically verifying that a log did indeed issue 81an SCT, some confidence can be gained that the certificate is publicly known. 82 83An internal representation of an SCT can be created in one of two ways. 84The first option is to create a blank SCT, using SCT_new(), and then populate 85it using: 86 87=over 2 88 89=item * 90 91SCT_set_version() to set the SCT version. 92 93Only SCT_VERSION_V1 is currently supported. 94 95=item * 96 97SCT_set_log_entry_type() to set the type of certificate the SCT was issued for: 98 99B<CT_LOG_ENTRY_TYPE_X509> for a normal certificate. 100B<CT_LOG_ENTRY_TYPE_PRECERT> for a pre-certificate. 101 102=item * 103 104SCT_set0_log_id() or SCT_set1_log_id() to set the LogID of the CT log that the SCT came from. 105 106The former takes ownership, whereas the latter makes a copy. 107See RFC 6962, Section 3.2 for the definition of LogID. 108 109=item * 110 111SCT_set_timestamp() to set the time the SCT was issued (time in milliseconds 112since the Unix Epoch). 113 114=item * 115 116SCT_set_signature_nid() to set the NID of the signature. 117 118=item * 119 120SCT_set0_signature() or SCT_set1_signature() to set the raw signature value. 121 122The former takes ownership, whereas the latter makes a copy. 123 124=item * 125 126SCT_set0_extensions() or B<SCT_set1_extensions> to provide SCT extensions. 127 128The former takes ownership, whereas the latter makes a copy. 129 130=back 131 132Alternatively, the SCT can be pre-populated from the following data using 133SCT_new_from_base64(): 134 135=over 2 136 137=item * 138 139The SCT version (only SCT_VERSION_V1 is currently supported). 140 141=item * 142 143The LogID (see RFC 6962, Section 3.2), base64 encoded. 144 145=item * 146 147The type of certificate the SCT was issued for: 148B<CT_LOG_ENTRY_TYPE_X509> for a normal certificate. 149B<CT_LOG_ENTRY_TYPE_PRECERT> for a pre-certificate. 150 151=item * 152 153The time that the SCT was issued (time in milliseconds since the Unix Epoch). 154 155=item * 156 157The SCT extensions, base64 encoded. 158 159=item * 160 161The SCT signature, base64 encoded. 162 163=back 164 165SCT_set_source() can be used to record where the SCT was found 166(TLS extension, X.509 certificate extension or OCSP response). This is not 167required for verifying the SCT. 168 169SCT_free() frees the specified SCT. 170If the argument is NULL, nothing is done. 171 172SCT_LIST_free() frees the specified stack of SCTs. 173If the argument is NULL, nothing is done. 174 175=head1 NOTES 176 177Some of the setters return int, instead of void. These will all return 1 on 178success, 0 on failure. They will not make changes on failure. 179 180All of the setters will reset the validation status of the SCT to 181SCT_VALIDATION_STATUS_NOT_SET (see L<SCT_validate(3)>). 182 183SCT_set_source() will call SCT_set_log_entry_type() if the type of 184certificate the SCT was issued for can be inferred from where the SCT was found. 185For example, an SCT found in an X.509 extension must have been issued for a pre- 186certificate. 187 188SCT_set_source() will not refuse unknown values. 189 190=head1 RETURN VALUES 191 192SCT_set_version() returns 1 if the specified version is supported, 0 otherwise. 193 194SCT_set_log_entry_type() returns 1 if the specified log entry type is supported, 0 otherwise. 195 196SCT_set0_log_id() and B<SCT_set1_log_id> return 1 if the specified LogID is a 197valid SHA-256 hash, 0 otherwise. Additionally, B<SCT_set1_log_id> returns 0 if 198malloc fails. 199 200B<SCT_set_signature_nid> returns 1 if the specified NID is supported, 0 otherwise. 201 202B<SCT_set1_extensions> and B<SCT_set1_signature> return 1 if the supplied buffer 203is copied successfully, 0 otherwise (i.e. if malloc fails). 204 205B<SCT_set_source> returns 1 on success, 0 otherwise. 206 207=head1 SEE ALSO 208 209L<ct(7)>, 210L<SCT_validate(3)>, 211L<OBJ_nid2obj(3)> 212 213=head1 HISTORY 214 215These functions were added in OpenSSL 1.1.0. 216 217=head1 COPYRIGHT 218 219Copyright 2016-2024 The OpenSSL Project Authors. All Rights Reserved. 220 221Licensed under the Apache License 2.0 (the "License"). You may not use 222this file except in compliance with the License. You can obtain a copy 223in the file LICENSE in the source distribution or at 224L<https://www.openssl.org/source/license.html>. 225 226=cut 227
