/src/openssl30/crypto/ct/ct_sct.c

Source
/*
 * Copyright 2016-2021 The OpenSSL Project Authors. All Rights Reserved.
 *
 * Licensed under the Apache License 2.0 (the "License").  You may not use
 * this file except in compliance with the License.  You can obtain a copy
 * in the file LICENSE in the source distribution or at
 * https://www.openssl.org/source/license.html
 */

#ifdef OPENSSL_NO_CT
#error "CT disabled"
#endif

#include <openssl/ct.h>
#include <openssl/err.h>
#include <openssl/evp.h>
#include <openssl/tls1.h>
#include <openssl/x509.h>

#include "ct_local.h"

SCT *SCT_new(void)
{
    SCT *sct = OPENSSL_zalloc(sizeof(*sct));

    if (sct == NULL) {
        ERR_raise(ERR_LIB_CT, ERR_R_MALLOC_FAILURE);
        return NULL;
    }

    sct->entry_type = CT_LOG_ENTRY_TYPE_NOT_SET;
    sct->version = SCT_VERSION_NOT_SET;
    return sct;
}

void SCT_free(SCT *sct)
{
    if (sct == NULL)
        return;

    OPENSSL_free(sct->log_id);
    OPENSSL_free(sct->ext);
    OPENSSL_free(sct->sig);
    OPENSSL_free(sct->sct);
    OPENSSL_free(sct);
}

void SCT_LIST_free(STACK_OF(SCT) *a)
{
    sk_SCT_pop_free(a, SCT_free);
}

int SCT_set_version(SCT *sct, sct_version_t version)
{
    if (version != SCT_VERSION_V1) {
        ERR_raise(ERR_LIB_CT, CT_R_UNSUPPORTED_VERSION);
        return 0;
    }
    sct->version = version;
    sct->validation_status = SCT_VALIDATION_STATUS_NOT_SET;
    return 1;
}

int SCT_set_log_entry_type(SCT *sct, ct_log_entry_type_t entry_type)
{
    sct->validation_status = SCT_VALIDATION_STATUS_NOT_SET;

    switch (entry_type) {
    case CT_LOG_ENTRY_TYPE_X509:
    case CT_LOG_ENTRY_TYPE_PRECERT:
        sct->entry_type = entry_type;
        return 1;
    case CT_LOG_ENTRY_TYPE_NOT_SET:
        break;
    }
    ERR_raise(ERR_LIB_CT, CT_R_UNSUPPORTED_ENTRY_TYPE);
    return 0;
}

int SCT_set0_log_id(SCT *sct, unsigned char *log_id, size_t log_id_len)
{
    if (sct->version == SCT_VERSION_V1 && log_id_len != CT_V1_HASHLEN) {
        ERR_raise(ERR_LIB_CT, CT_R_INVALID_LOG_ID_LENGTH);
        return 0;
    }

    OPENSSL_free(sct->log_id);
    sct->log_id = log_id;
    sct->log_id_len = log_id_len;
    sct->validation_status = SCT_VALIDATION_STATUS_NOT_SET;
    return 1;
}

int SCT_set1_log_id(SCT *sct, const unsigned char *log_id, size_t log_id_len)
{
    if (sct->version == SCT_VERSION_V1 && log_id_len != CT_V1_HASHLEN) {
        ERR_raise(ERR_LIB_CT, CT_R_INVALID_LOG_ID_LENGTH);
        return 0;
    }

    OPENSSL_free(sct->log_id);
    sct->log_id = NULL;
    sct->log_id_len = 0;
    sct->validation_status = SCT_VALIDATION_STATUS_NOT_SET;

    if (log_id != NULL && log_id_len > 0) {
        sct->log_id = OPENSSL_memdup(log_id, log_id_len);
        if (sct->log_id == NULL) {
            ERR_raise(ERR_LIB_CT, ERR_R_MALLOC_FAILURE);
            return 0;
        }
        sct->log_id_len = log_id_len;
    }
    return 1;
}

void SCT_set_timestamp(SCT *sct, uint64_t timestamp)
{
    sct->timestamp = timestamp;
    sct->validation_status = SCT_VALIDATION_STATUS_NOT_SET;
}

int SCT_set_signature_nid(SCT *sct, int nid)
{
    switch (nid) {
    case NID_sha256WithRSAEncryption:
        sct->hash_alg = TLSEXT_hash_sha256;
        sct->sig_alg = TLSEXT_signature_rsa;
        sct->validation_status = SCT_VALIDATION_STATUS_NOT_SET;
        return 1;
    case NID_ecdsa_with_SHA256:
        sct->hash_alg = TLSEXT_hash_sha256;
        sct->sig_alg = TLSEXT_signature_ecdsa;
        sct->validation_status = SCT_VALIDATION_STATUS_NOT_SET;
        return 1;
    default:
        ERR_raise(ERR_LIB_CT, CT_R_UNRECOGNIZED_SIGNATURE_NID);
        return 0;
    }
}

void SCT_set0_extensions(SCT *sct, unsigned char *ext, size_t ext_len)
{
    OPENSSL_free(sct->ext);
    sct->ext = ext;
    sct->ext_len = ext_len;
    sct->validation_status = SCT_VALIDATION_STATUS_NOT_SET;
}

int SCT_set1_extensions(SCT *sct, const unsigned char *ext, size_t ext_len)
{
    OPENSSL_free(sct->ext);
    sct->ext = NULL;
    sct->ext_len = 0;
    sct->validation_status = SCT_VALIDATION_STATUS_NOT_SET;

    if (ext != NULL && ext_len > 0) {
        sct->ext = OPENSSL_memdup(ext, ext_len);
        if (sct->ext == NULL) {
            ERR_raise(ERR_LIB_CT, ERR_R_MALLOC_FAILURE);
            return 0;
        }
        sct->ext_len = ext_len;
    }
    return 1;
}

void SCT_set0_signature(SCT *sct, unsigned char *sig, size_t sig_len)
{
    OPENSSL_free(sct->sig);
    sct->sig = sig;
    sct->sig_len = sig_len;
    sct->validation_status = SCT_VALIDATION_STATUS_NOT_SET;
}

int SCT_set1_signature(SCT *sct, const unsigned char *sig, size_t sig_len)
{
    OPENSSL_free(sct->sig);
    sct->sig = NULL;
    sct->sig_len = 0;
    sct->validation_status = SCT_VALIDATION_STATUS_NOT_SET;

    if (sig != NULL && sig_len > 0) {
        sct->sig = OPENSSL_memdup(sig, sig_len);
        if (sct->sig == NULL) {
            ERR_raise(ERR_LIB_CT, ERR_R_MALLOC_FAILURE);
            return 0;
        }
        sct->sig_len = sig_len;
    }
    return 1;
}

sct_version_t SCT_get_version(const SCT *sct)
{
    return sct->version;
}

ct_log_entry_type_t SCT_get_log_entry_type(const SCT *sct)
{
    return sct->entry_type;
}

size_t SCT_get0_log_id(const SCT *sct, unsigned char **log_id)
{
    *log_id = sct->log_id;
    return sct->log_id_len;
}

uint64_t SCT_get_timestamp(const SCT *sct)
{
    return sct->timestamp;
}

int SCT_get_signature_nid(const SCT *sct)
{
    if (sct->version == SCT_VERSION_V1) {
        if (sct->hash_alg == TLSEXT_hash_sha256) {
            switch (sct->sig_alg) {
            case TLSEXT_signature_ecdsa:
                return NID_ecdsa_with_SHA256;
            case TLSEXT_signature_rsa:
                return NID_sha256WithRSAEncryption;
            default:
                return NID_undef;
            }
        }
    }
    return NID_undef;
}

size_t SCT_get0_extensions(const SCT *sct, unsigned char **ext)
{
    *ext = sct->ext;
    return sct->ext_len;
}

size_t SCT_get0_signature(const SCT *sct, unsigned char **sig)
{
    *sig = sct->sig;
    return sct->sig_len;
}

int SCT_is_complete(const SCT *sct)
{
    switch (sct->version) {
    case SCT_VERSION_NOT_SET:
        return 0;
    case SCT_VERSION_V1:
        return sct->log_id != NULL && SCT_signature_is_complete(sct);
    default:
        return sct->sct != NULL; /* Just need cached encoding */
    }
}

int SCT_signature_is_complete(const SCT *sct)
{
    return SCT_get_signature_nid(sct) != NID_undef && sct->sig != NULL && sct->sig_len > 0;
}

sct_source_t SCT_get_source(const SCT *sct)
{
    return sct->source;
}

int SCT_set_source(SCT *sct, sct_source_t source)
{
    sct->source = source;
    sct->validation_status = SCT_VALIDATION_STATUS_NOT_SET;
    switch (source) {
    case SCT_SOURCE_TLS_EXTENSION:
    case SCT_SOURCE_OCSP_STAPLED_RESPONSE:
        return SCT_set_log_entry_type(sct, CT_LOG_ENTRY_TYPE_X509);
    case SCT_SOURCE_X509V3_EXTENSION:
        return SCT_set_log_entry_type(sct, CT_LOG_ENTRY_TYPE_PRECERT);
    case SCT_SOURCE_UNKNOWN:
        break;
    }
    /* if we aren't sure, leave the log entry type alone */
    return 1;
}

sct_validation_status_t SCT_get_validation_status(const SCT *sct)
{
    return sct->validation_status;
}

int SCT_validate(SCT *sct, const CT_POLICY_EVAL_CTX *ctx)
{
    int is_sct_valid = -1;
    SCT_CTX *sctx = NULL;
    X509_PUBKEY *pub = NULL, *log_pkey = NULL;
    const CTLOG *log;

    /*
     * With an unrecognized SCT version we don't know what such an SCT means,
     * let alone validate one.  So we return validation failure (0).
     */
    if (sct->version != SCT_VERSION_V1) {
        sct->validation_status = SCT_VALIDATION_STATUS_UNKNOWN_VERSION;
        return 0;
    }

    log = CTLOG_STORE_get0_log_by_id(ctx->log_store,
        sct->log_id, sct->log_id_len);

    /* Similarly, an SCT from an unknown log also cannot be validated. */
    if (log == NULL) {
        sct->validation_status = SCT_VALIDATION_STATUS_UNKNOWN_LOG;
        return 0;
    }

    sctx = SCT_CTX_new(ctx->libctx, ctx->propq);
    if (sctx == NULL)
        goto err;

    if (X509_PUBKEY_set(&log_pkey, CTLOG_get0_public_key(log)) != 1)
        goto err;
    if (SCT_CTX_set1_pubkey(sctx, log_pkey) != 1)
        goto err;

    if (SCT_get_log_entry_type(sct) == CT_LOG_ENTRY_TYPE_PRECERT) {
        EVP_PKEY *issuer_pkey;

        if (ctx->issuer == NULL) {
            sct->validation_status = SCT_VALIDATION_STATUS_UNVERIFIED;
            goto end;
        }

        issuer_pkey = X509_get0_pubkey(ctx->issuer);

        if (X509_PUBKEY_set(&pub, issuer_pkey) != 1)
            goto err;
        if (SCT_CTX_set1_issuer_pubkey(sctx, pub) != 1)
            goto err;
    }

    SCT_CTX_set_time(sctx, ctx->epoch_time_in_ms);

    /*
     * XXX: Potential for optimization.  This repeats some idempotent heavy
     * lifting on the certificate for each candidate SCT, and appears to not
     * use any information in the SCT itself, only the certificate is
     * processed.  So it may make more sense to do this just once, perhaps
     * associated with the shared (by all SCTs) policy eval ctx.
     *
     * XXX: Failure here is global (SCT independent) and represents either an
     * issue with the certificate (e.g. duplicate extensions) or an out of
     * memory condition.  When the certificate is incompatible with CT, we just
     * mark the SCTs invalid, rather than report a failure to determine the
     * validation status.  That way, callbacks that want to do "soft" SCT
     * processing will not abort handshakes with false positive internal
     * errors.  Since the function does not distinguish between certificate
     * issues (peer's fault) and internal problems (out fault) the safe thing
     * to do is to report a validation failure and let the callback or
     * application decide what to do.
     */
    if (SCT_CTX_set1_cert(sctx, ctx->cert, NULL) != 1)
        sct->validation_status = SCT_VALIDATION_STATUS_UNVERIFIED;
    else
        sct->validation_status = SCT_CTX_verify(sctx, sct) == 1 ? SCT_VALIDATION_STATUS_VALID : SCT_VALIDATION_STATUS_INVALID;

end:
    is_sct_valid = sct->validation_status == SCT_VALIDATION_STATUS_VALID;
err:
    X509_PUBKEY_free(pub);
    X509_PUBKEY_free(log_pkey);
    SCT_CTX_free(sctx);

    return is_sct_valid;
}

int SCT_LIST_validate(const STACK_OF(SCT) *scts, CT_POLICY_EVAL_CTX *ctx)
{
    int are_scts_valid = 1;
    int sct_count = scts != NULL ? sk_SCT_num(scts) : 0;
    int i;

    for (i = 0; i < sct_count; ++i) {
        int is_sct_valid = -1;
        SCT *sct = sk_SCT_value(scts, i);

        if (sct == NULL)
            continue;

        is_sct_valid = SCT_validate(sct, ctx);
        if (is_sct_valid < 0)
            return is_sct_valid;
        are_scts_valid &= is_sct_valid;
    }

    return are_scts_valid;
}

Coverage Report

Created: 2025-12-31 06:58

Line	Count	Source
1		/*
2		* Copyright 2016-2021 The OpenSSL Project Authors. All Rights Reserved.
3		*
4		* Licensed under the Apache License 2.0 (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		#ifdef OPENSSL_NO_CT
11		#error "CT disabled"
12		#endif
13
14		#include <openssl/ct.h>
15		#include <openssl/err.h>
16		#include <openssl/evp.h>
17		#include <openssl/tls1.h>
18		#include <openssl/x509.h>
19
20		#include "ct_local.h"
21
22		SCT *SCT_new(void)
23	959k	{
24	959k	SCT sct = OPENSSL_zalloc(sizeof(sct));
25
26	959k	if (sct == NULL) {
27	0	ERR_raise(ERR_LIB_CT, ERR_R_MALLOC_FAILURE);
28	0	return NULL;
29	0	}
30
31	959k	sct->entry_type = CT_LOG_ENTRY_TYPE_NOT_SET;
32	959k	sct->version = SCT_VERSION_NOT_SET;
33	959k	return sct;
34	959k	}
35
36		void SCT_free(SCT *sct)
37	959k	{
38	959k	if (sct == NULL)
39	0	return;
40
41	959k	OPENSSL_free(sct->log_id);
42	959k	OPENSSL_free(sct->ext);
43	959k	OPENSSL_free(sct->sig);
44	959k	OPENSSL_free(sct->sct);
45	959k	OPENSSL_free(sct);
46	959k	}
47
48		void SCT_LIST_free(STACK_OF(SCT) *a)
49	290k	{
50	290k	sk_SCT_pop_free(a, SCT_free);
51	290k	}
52
53		int SCT_set_version(SCT *sct, sct_version_t version)
54	0	{
55	0	if (version != SCT_VERSION_V1) {
56	0	ERR_raise(ERR_LIB_CT, CT_R_UNSUPPORTED_VERSION);
57	0	return 0;
58	0	}
59	0	sct->version = version;
60	0	sct->validation_status = SCT_VALIDATION_STATUS_NOT_SET;
61	0	return 1;
62	0	}
63
64		int SCT_set_log_entry_type(SCT *sct, ct_log_entry_type_t entry_type)
65	106k	{
66	106k	sct->validation_status = SCT_VALIDATION_STATUS_NOT_SET;
67
68	106k	switch (entry_type) {
69	68.7k	case CT_LOG_ENTRY_TYPE_X509:
70	106k	case CT_LOG_ENTRY_TYPE_PRECERT:
71	106k	sct->entry_type = entry_type;
72	106k	return 1;
73	0	case CT_LOG_ENTRY_TYPE_NOT_SET:
74	0	break;
75	106k	}
76	106k	ERR_raise(ERR_LIB_CT, CT_R_UNSUPPORTED_ENTRY_TYPE);
77	0	return 0;
78	106k	}
79
80		int SCT_set0_log_id(SCT sct, unsigned char log_id, size_t log_id_len)
81	0	{
82	0	if (sct->version == SCT_VERSION_V1 && log_id_len != CT_V1_HASHLEN) {
83	0	ERR_raise(ERR_LIB_CT, CT_R_INVALID_LOG_ID_LENGTH);
84	0	return 0;
85	0	}
86
87	0	OPENSSL_free(sct->log_id);
88	0	sct->log_id = log_id;
89	0	sct->log_id_len = log_id_len;
90	0	sct->validation_status = SCT_VALIDATION_STATUS_NOT_SET;
91	0	return 1;
92	0	}
93
94		int SCT_set1_log_id(SCT sct, const unsigned char log_id, size_t log_id_len)
95	0	{
96	0	if (sct->version == SCT_VERSION_V1 && log_id_len != CT_V1_HASHLEN) {
97	0	ERR_raise(ERR_LIB_CT, CT_R_INVALID_LOG_ID_LENGTH);
98	0	return 0;
99	0	}
100
101	0	OPENSSL_free(sct->log_id);
102	0	sct->log_id = NULL;
103	0	sct->log_id_len = 0;
104	0	sct->validation_status = SCT_VALIDATION_STATUS_NOT_SET;
105
106	0	if (log_id != NULL && log_id_len > 0) {
107	0	sct->log_id = OPENSSL_memdup(log_id, log_id_len);
108	0	if (sct->log_id == NULL) {
109	0	ERR_raise(ERR_LIB_CT, ERR_R_MALLOC_FAILURE);
110	0	return 0;
111	0	}
112	0	sct->log_id_len = log_id_len;
113	0	}
114	0	return 1;
115	0	}
116
117		void SCT_set_timestamp(SCT *sct, uint64_t timestamp)
118	0	{
119	0	sct->timestamp = timestamp;
120	0	sct->validation_status = SCT_VALIDATION_STATUS_NOT_SET;
121	0	}
122
123		int SCT_set_signature_nid(SCT *sct, int nid)
124	0	{
125	0	switch (nid) {
126	0	case NID_sha256WithRSAEncryption:
127	0	sct->hash_alg = TLSEXT_hash_sha256;
128	0	sct->sig_alg = TLSEXT_signature_rsa;
129	0	sct->validation_status = SCT_VALIDATION_STATUS_NOT_SET;
130	0	return 1;
131	0	case NID_ecdsa_with_SHA256:
132	0	sct->hash_alg = TLSEXT_hash_sha256;
133	0	sct->sig_alg = TLSEXT_signature_ecdsa;
134	0	sct->validation_status = SCT_VALIDATION_STATUS_NOT_SET;
135	0	return 1;
136	0	default:
137	0	ERR_raise(ERR_LIB_CT, CT_R_UNRECOGNIZED_SIGNATURE_NID);
138	0	return 0;
139	0	}
140	0	}
141
142		void SCT_set0_extensions(SCT sct, unsigned char ext, size_t ext_len)
143	0	{
144	0	OPENSSL_free(sct->ext);
145	0	sct->ext = ext;
146	0	sct->ext_len = ext_len;
147	0	sct->validation_status = SCT_VALIDATION_STATUS_NOT_SET;
148	0	}
149
150		int SCT_set1_extensions(SCT sct, const unsigned char ext, size_t ext_len)
151	0	{
152	0	OPENSSL_free(sct->ext);
153	0	sct->ext = NULL;
154	0	sct->ext_len = 0;
155	0	sct->validation_status = SCT_VALIDATION_STATUS_NOT_SET;
156
157	0	if (ext != NULL && ext_len > 0) {
158	0	sct->ext = OPENSSL_memdup(ext, ext_len);
159	0	if (sct->ext == NULL) {
160	0	ERR_raise(ERR_LIB_CT, ERR_R_MALLOC_FAILURE);
161	0	return 0;
162	0	}
163	0	sct->ext_len = ext_len;
164	0	}
165	0	return 1;
166	0	}
167
168		void SCT_set0_signature(SCT sct, unsigned char sig, size_t sig_len)
169	0	{
170	0	OPENSSL_free(sct->sig);
171	0	sct->sig = sig;
172	0	sct->sig_len = sig_len;
173	0	sct->validation_status = SCT_VALIDATION_STATUS_NOT_SET;
174	0	}
175
176		int SCT_set1_signature(SCT sct, const unsigned char sig, size_t sig_len)
177	96.6k	{
178	96.6k	OPENSSL_free(sct->sig);
179	96.6k	sct->sig = NULL;
180	96.6k	sct->sig_len = 0;
181	96.6k	sct->validation_status = SCT_VALIDATION_STATUS_NOT_SET;
182
183	96.6k	if (sig != NULL && sig_len > 0) {
184	40.7k	sct->sig = OPENSSL_memdup(sig, sig_len);
185	40.7k	if (sct->sig == NULL) {
186	0	ERR_raise(ERR_LIB_CT, ERR_R_MALLOC_FAILURE);
187	0	return 0;
188	0	}
189	40.7k	sct->sig_len = sig_len;
190	40.7k	}
191	96.6k	return 1;
192	96.6k	}
193
194		sct_version_t SCT_get_version(const SCT *sct)
195	0	{
196	0	return sct->version;
197	0	}
198
199		ct_log_entry_type_t SCT_get_log_entry_type(const SCT *sct)
200	0	{
201	0	return sct->entry_type;
202	0	}
203
204		size_t SCT_get0_log_id(const SCT sct, unsigned char *log_id)
205	0	{
206	0	*log_id = sct->log_id;
207	0	return sct->log_id_len;
208	0	}
209
210		uint64_t SCT_get_timestamp(const SCT *sct)
211	0	{
212	0	return sct->timestamp;
213	0	}
214
215		int SCT_get_signature_nid(const SCT *sct)
216	252k	{
217	252k	if (sct->version == SCT_VERSION_V1) {
218	252k	if (sct->hash_alg == TLSEXT_hash_sha256) {
219	243k	switch (sct->sig_alg) {
220	48.7k	case TLSEXT_signature_ecdsa:
221	48.7k	return NID_ecdsa_with_SHA256;
222	192k	case TLSEXT_signature_rsa:
223	192k	return NID_sha256WithRSAEncryption;
224	1.69k	default:
225	1.69k	return NID_undef;
226	243k	}
227	243k	}
228	252k	}
229	8.72k	return NID_undef;
230	252k	}
231
232		size_t SCT_get0_extensions(const SCT sct, unsigned char *ext)
233	0	{
234	0	*ext = sct->ext;
235	0	return sct->ext_len;
236	0	}
237
238		size_t SCT_get0_signature(const SCT sct, unsigned char *sig)
239	0	{
240	0	*sig = sct->sig;
241	0	return sct->sig_len;
242	0	}
243
244		int SCT_is_complete(const SCT *sct)
245	859k	{
246	859k	switch (sct->version) {
247	0	case SCT_VERSION_NOT_SET:
248	0	return 0;
249	28.9k	case SCT_VERSION_V1:
250	28.9k	return sct->log_id != NULL && SCT_signature_is_complete(sct);
251	830k	default:
252	830k	return sct->sct != NULL; /* Just need cached encoding */
253	859k	}
254	859k	}
255
256		int SCT_signature_is_complete(const SCT *sct)
257	41.9k	{
258	41.9k	return SCT_get_signature_nid(sct) != NID_undef && sct->sig != NULL && sct->sig_len > 0;
259	41.9k	}
260
261		sct_source_t SCT_get_source(const SCT *sct)
262	0	{
263	0	return sct->source;
264	0	}
265
266		int SCT_set_source(SCT *sct, sct_source_t source)
267	106k	{
268	106k	sct->source = source;
269	106k	sct->validation_status = SCT_VALIDATION_STATUS_NOT_SET;
270	106k	switch (source) {
271	0	case SCT_SOURCE_TLS_EXTENSION:
272	68.7k	case SCT_SOURCE_OCSP_STAPLED_RESPONSE:
273	68.7k	return SCT_set_log_entry_type(sct, CT_LOG_ENTRY_TYPE_X509);
274	37.2k	case SCT_SOURCE_X509V3_EXTENSION:
275	37.2k	return SCT_set_log_entry_type(sct, CT_LOG_ENTRY_TYPE_PRECERT);
276	0	case SCT_SOURCE_UNKNOWN:
277	0	break;
278	106k	}
279		/* if we aren't sure, leave the log entry type alone */
280	0	return 1;
281	106k	}
282
283		sct_validation_status_t SCT_get_validation_status(const SCT *sct)
284	0	{
285	0	return sct->validation_status;
286	0	}
287
288		int SCT_validate(SCT sct, const CT_POLICY_EVAL_CTX ctx)
289	0	{
290	0	int is_sct_valid = -1;
291	0	SCT_CTX *sctx = NULL;
292	0	X509_PUBKEY pub = NULL, log_pkey = NULL;
293	0	const CTLOG *log;
294
295		/*
296		* With an unrecognized SCT version we don't know what such an SCT means,
297		* let alone validate one. So we return validation failure (0).
298		*/
299	0	if (sct->version != SCT_VERSION_V1) {
300	0	sct->validation_status = SCT_VALIDATION_STATUS_UNKNOWN_VERSION;
301	0	return 0;
302	0	}
303
304	0	log = CTLOG_STORE_get0_log_by_id(ctx->log_store,
305	0	sct->log_id, sct->log_id_len);
306
307		/* Similarly, an SCT from an unknown log also cannot be validated. */
308	0	if (log == NULL) {
309	0	sct->validation_status = SCT_VALIDATION_STATUS_UNKNOWN_LOG;
310	0	return 0;
311	0	}
312
313	0	sctx = SCT_CTX_new(ctx->libctx, ctx->propq);
314	0	if (sctx == NULL)
315	0	goto err;
316
317	0	if (X509_PUBKEY_set(&log_pkey, CTLOG_get0_public_key(log)) != 1)
318	0	goto err;
319	0	if (SCT_CTX_set1_pubkey(sctx, log_pkey) != 1)
320	0	goto err;
321
322	0	if (SCT_get_log_entry_type(sct) == CT_LOG_ENTRY_TYPE_PRECERT) {
323	0	EVP_PKEY *issuer_pkey;
324
325	0	if (ctx->issuer == NULL) {
326	0	sct->validation_status = SCT_VALIDATION_STATUS_UNVERIFIED;
327	0	goto end;
328	0	}
329
330	0	issuer_pkey = X509_get0_pubkey(ctx->issuer);
331
332	0	if (X509_PUBKEY_set(&pub, issuer_pkey) != 1)
333	0	goto err;
334	0	if (SCT_CTX_set1_issuer_pubkey(sctx, pub) != 1)
335	0	goto err;
336	0	}
337
338	0	SCT_CTX_set_time(sctx, ctx->epoch_time_in_ms);
339
340		/*
341		* XXX: Potential for optimization. This repeats some idempotent heavy
342		* lifting on the certificate for each candidate SCT, and appears to not
343		* use any information in the SCT itself, only the certificate is
344		* processed. So it may make more sense to do this just once, perhaps
345		* associated with the shared (by all SCTs) policy eval ctx.
346		*
347		* XXX: Failure here is global (SCT independent) and represents either an
348		* issue with the certificate (e.g. duplicate extensions) or an out of
349		* memory condition. When the certificate is incompatible with CT, we just
350		* mark the SCTs invalid, rather than report a failure to determine the
351		* validation status. That way, callbacks that want to do "soft" SCT
352		* processing will not abort handshakes with false positive internal
353		* errors. Since the function does not distinguish between certificate
354		* issues (peer's fault) and internal problems (out fault) the safe thing
355		* to do is to report a validation failure and let the callback or
356		* application decide what to do.
357		*/
358	0	if (SCT_CTX_set1_cert(sctx, ctx->cert, NULL) != 1)
359	0	sct->validation_status = SCT_VALIDATION_STATUS_UNVERIFIED;
360	0	else
361	0	sct->validation_status = SCT_CTX_verify(sctx, sct) == 1 ? SCT_VALIDATION_STATUS_VALID : SCT_VALIDATION_STATUS_INVALID;
362
363	0	end:
364	0	is_sct_valid = sct->validation_status == SCT_VALIDATION_STATUS_VALID;
365	0	err:
366	0	X509_PUBKEY_free(pub);
367	0	X509_PUBKEY_free(log_pkey);
368	0	SCT_CTX_free(sctx);
369
370	0	return is_sct_valid;
371	0	}
372
373		int SCT_LIST_validate(const STACK_OF(SCT) scts, CT_POLICY_EVAL_CTX ctx)
374	0	{
375	0	int are_scts_valid = 1;
376	0	int sct_count = scts != NULL ? sk_SCT_num(scts) : 0;
377	0	int i;
378
379	0	for (i = 0; i < sct_count; ++i) {
380	0	int is_sct_valid = -1;
381	0	SCT *sct = sk_SCT_value(scts, i);
382
383	0	if (sct == NULL)
384	0	continue;
385
386	0	is_sct_valid = SCT_validate(sct, ctx);
387	0	if (is_sct_valid < 0)
388	0	return is_sct_valid;
389	0	are_scts_valid &= is_sct_valid;
390	0	}
391
392	0	return are_scts_valid;
393	0	}