int SCT_verify_v1(SCT *sct, X509 *cert, X509 *preissuer,
X509_PUBKEY *log_pubkey, X509 *issuer_cert)
{
int ret = 0;
SCT_CTX *sctx = NULL;
if (!SCT_is_complete(sct)) {
CTerr(CT_F_SCT_VERIFY_V1, CT_R_SCT_NOT_SET);
return 0;
}
if (sct->version != 0) {
CTerr(CT_F_SCT_VERIFY_V1, CT_R_SCT_UNSUPPORTED_VERSION);
return 0;
}
sctx = SCT_CTX_new();
if (sctx == NULL)
goto done;
if (!SCT_CTX_set1_pubkey(sctx, log_pubkey))
goto done;
if (!SCT_CTX_set1_cert(sctx, cert, preissuer))
goto done;
if (sct->entry_type == CT_LOG_ENTRY_TYPE_PRECERT &&
!SCT_CTX_set1_issuer(sctx, issuer_cert))
goto done;
ret = SCT_verify(sctx, sct);
done:
SCT_CTX_free(sctx);
return ret;
}
/*
* Decodes the base64 string |in| into |out|.
* A new string will be malloc'd and assigned to |out|. This will be owned by
* the caller. Do not provide a pre-allocated string in |out|.
*/
static int ct_base64_decode(const char *in, unsigned char **out)
{
size_t inlen = strlen(in);
int outlen;
unsigned char *outbuf = NULL;
if (inlen == 0) {
*out = NULL;
return 0;
}
outlen = (inlen / 4) * 3;
outbuf = OPENSSL_malloc(outlen);
if (outbuf == NULL) {
CTerr(CT_F_CT_BASE64_DECODE, ERR_R_MALLOC_FAILURE);
goto err;
}
outlen = EVP_DecodeBlock(outbuf, (unsigned char *)in, inlen);
if (outlen < 0) {
CTerr(CT_F_CT_BASE64_DECODE, CT_R_BASE64_DECODE_ERROR);
goto err;
}
*out = outbuf;
return outlen;
err:
OPENSSL_free(outbuf);
return -1;
}
/*
* This methods returns: 1 on Success,
* 0 on decoding failure,
* -1 on internal (malloc) failure, or invalid parameter if any.
*/
int CTLOG_new_from_base64(CTLOG **ct_log, const char *pkey_base64, const char *name)
{
unsigned char *pkey_der = NULL;
int pkey_der_len = ct_base64_decode(pkey_base64, &pkey_der);
const unsigned char *p;
EVP_PKEY *pkey = NULL;
if (ct_log == NULL) {
CTerr(CT_F_CTLOG_NEW_FROM_BASE64, ERR_R_PASSED_INVALID_ARGUMENT);
return 0;
}
if (pkey_der_len <= 0) {
CTerr(CT_F_CTLOG_NEW_FROM_BASE64, CT_R_LOG_CONF_INVALID_KEY);
return 0;
}
p = pkey_der;
pkey = d2i_PUBKEY(NULL, &p, pkey_der_len);
OPENSSL_free(pkey_der);
if (pkey == NULL) {
CTerr(CT_F_CTLOG_NEW_FROM_BASE64, CT_R_LOG_CONF_INVALID_KEY);
return 0;
}
*ct_log = CTLOG_new(pkey, name);
if (*ct_log == NULL) {
EVP_PKEY_free(pkey);
return -1;
}
return 1;
}
int i2o_SCT(const SCT *sct, unsigned char **out)
{
size_t len;
unsigned char *p = NULL, *pstart = NULL;
if (!SCT_is_complete(sct)) {
CTerr(CT_F_I2O_SCT, CT_R_SCT_NOT_SET);
goto err;
}
/*
* Fixed-length header: struct { (1 byte) Version sct_version; (32 bytes)
* log_id id; (8 bytes) uint64 timestamp; (2 bytes + ?) CtExtensions
* extensions; (1 byte) Hash algorithm (1 byte) Signature algorithm (2
* bytes + ?) Signature
*/
if (sct->version == SCT_VERSION_V1)
len = 43 + sct->ext_len + 4 + sct->sig_len;
else
len = sct->sct_len;
if (out == NULL)
return len;
if (*out != NULL) {
p = *out;
*out += len;
} else {
pstart = p = OPENSSL_malloc(len);
if (p == NULL) {
CTerr(CT_F_I2O_SCT, ERR_R_MALLOC_FAILURE);
goto err;
}
*out = p;
}
if (sct->version == SCT_VERSION_V1) {
*p++ = sct->version;
memcpy(p, sct->log_id, CT_V1_HASHLEN);
p += CT_V1_HASHLEN;
l2n8(sct->timestamp, p);
s2n(sct->ext_len, p);
if (sct->ext_len > 0) {
memcpy(p, sct->ext, sct->ext_len);
p += sct->ext_len;
}
if (i2o_SCT_signature(sct, &p) <= 0)
goto err;
} else {
memcpy(p, sct->sct, len);
}
return len;
err:
OPENSSL_free(pstart);
return -1;
}
int i2o_SCT_signature(const SCT *sct, unsigned char **out)
{
size_t len;
unsigned char *p = NULL, *pstart = NULL;
if (!SCT_signature_is_complete(sct)) {
CTerr(CT_F_I2O_SCT_SIGNATURE, CT_R_SCT_INVALID_SIGNATURE);
goto err;
}
if (sct->version != SCT_VERSION_V1) {
CTerr(CT_F_I2O_SCT_SIGNATURE, CT_R_UNSUPPORTED_VERSION);
goto err;
}
/*
* (1 byte) Hash algorithm
* (1 byte) Signature algorithm
* (2 bytes + ?) Signature
*/
len = 4 + sct->sig_len;
if (out != NULL) {
if (*out != NULL) {
p = *out;
*out += len;
} else {
pstart = p = OPENSSL_malloc(len);
if (p == NULL) {
CTerr(CT_F_I2O_SCT_SIGNATURE, ERR_R_MALLOC_FAILURE);
goto err;
}
*out = p;
}
*p++ = sct->hash_alg;
*p++ = sct->sig_alg;
s2n(sct->sig_len, p);
memcpy(p, sct->sig, sct->sig_len);
}
return len;
err:
OPENSSL_free(pstart);
return -1;
}
int o2i_SCT_signature(SCT *sct, const unsigned char **in, size_t len)
{
size_t siglen;
size_t len_remaining = len;
const unsigned char *p;
if (sct->version != SCT_VERSION_V1) {
CTerr(CT_F_O2I_SCT_SIGNATURE, CT_R_UNSUPPORTED_VERSION);
return -1;
}
/*
* digitally-signed struct header: (1 byte) Hash algorithm (1 byte)
* Signature algorithm (2 bytes + ?) Signature
*
* This explicitly rejects empty signatures: they're invalid for
* all supported algorithms.
*/
if (len <= 4) {
CTerr(CT_F_O2I_SCT_SIGNATURE, CT_R_SCT_INVALID_SIGNATURE);
return -1;
}
p = *in;
/* Get hash and signature algorithm */
sct->hash_alg = *p++;
sct->sig_alg = *p++;
if (SCT_get_signature_nid(sct) == NID_undef) {
CTerr(CT_F_O2I_SCT_SIGNATURE, CT_R_SCT_INVALID_SIGNATURE);
return -1;
}
/* Retrieve signature and check it is consistent with the buffer length */
n2s(p, siglen);
len_remaining -= (p - *in);
if (siglen > len_remaining) {
CTerr(CT_F_O2I_SCT_SIGNATURE, CT_R_SCT_INVALID_SIGNATURE);
return -1;
}
if (SCT_set1_signature(sct, p, siglen) != 1)
return -1;
len_remaining -= siglen;
*in = p + siglen;
return len - len_remaining;
}
SCT_CTX *SCT_CTX_new(void)
{
SCT_CTX *sctx = OPENSSL_zalloc(sizeof(*sctx));
if (sctx == NULL)
CTerr(CT_F_SCT_CTX_NEW, ERR_R_MALLOC_FAILURE);
return sctx;
}
int SCT_set_version(SCT *sct, sct_version_t version)
{
if (version != SCT_V1) {
CTerr(CT_F_SCT_SET_VERSION, CT_R_UNSUPPORTED_VERSION);
return 0;
}
sct->version = version;
return 1;
}
int SCT_set_log_entry_type(SCT *sct, log_entry_type_t entry_type)
{
if (entry_type != X509_ENTRY && entry_type != PRECERT_ENTRY) {
CTerr(CT_F_SCT_SET_LOG_ENTRY_TYPE, CT_R_UNSUPPORTED_ENTRY_TYPE);
return 0;
}
sct->entry_type = entry_type;
return 1;
}
int SCT_set_version(SCT *sct, sct_version_t version)
{
if (version != SCT_VERSION_V1) {
CTerr(CT_F_SCT_SET_VERSION, CT_R_UNSUPPORTED_VERSION);
return 0;
}
sct->version = version;
sct->validation_status = SCT_VALIDATION_STATUS_NOT_SET;
return 1;
}
CT_POLICY_EVAL_CTX *CT_POLICY_EVAL_CTX_new(void)
{
CT_POLICY_EVAL_CTX *ctx = OPENSSL_zalloc(sizeof(CT_POLICY_EVAL_CTX));
if (ctx == NULL) {
CTerr(CT_F_CT_POLICY_EVAL_CTX_NEW, ERR_R_MALLOC_FAILURE);
return NULL;
}
return ctx;
}
SCT *SCT_new(void)
{
SCT *sct = OPENSSL_zalloc(sizeof(SCT));
if (sct == NULL) {
CTerr(CT_F_SCT_NEW, ERR_R_MALLOC_FAILURE);
return NULL;
}
sct->entry_type = UNSET_ENTRY;
sct->version = UNSET_VERSION;
return sct;
}
int SCT_verify(const SCT_CTX *sctx, const SCT *sct)
{
EVP_MD_CTX *ctx = NULL;
int ret = 0;
if (!SCT_is_complete(sct) || sctx->pkey == NULL ||
sct->entry_type == CT_LOG_ENTRY_TYPE_NOT_SET ||
(sct->entry_type == CT_LOG_ENTRY_TYPE_PRECERT && sctx->ihash == NULL)) {
CTerr(CT_F_SCT_VERIFY, CT_R_SCT_NOT_SET);
return 0;
}
if (sct->version != SCT_VERSION_V1) {
CTerr(CT_F_SCT_VERIFY, CT_R_SCT_UNSUPPORTED_VERSION);
return 0;
}
if (sct->log_id_len != sctx->pkeyhashlen ||
memcmp(sct->log_id, sctx->pkeyhash, sctx->pkeyhashlen) != 0) {
CTerr(CT_F_SCT_VERIFY, CT_R_SCT_LOG_ID_MISMATCH);
return 0;
}
ctx = EVP_MD_CTX_new();
if (ctx == NULL)
goto end;
if (!EVP_DigestVerifyInit(ctx, NULL, EVP_sha256(), NULL, sctx->pkey))
goto end;
if (!sct_ctx_update(ctx, sctx, sct))
goto end;
/* Verify signature */
ret = EVP_DigestVerifyFinal(ctx, sct->sig, sct->sig_len);
/* If ret < 0 some other error: fall through without setting error */
if (ret == 0)
CTerr(CT_F_SCT_VERIFY, CT_R_SCT_INVALID_SIGNATURE);
end:
EVP_MD_CTX_free(ctx);
return ret;
}
int SCT_set0_log_id(SCT *sct, unsigned char *log_id, size_t log_id_len)
{
/* Currently only SHA-256 allowed so length must be SCT_V1_HASHLEN */
if (log_id_len != SCT_V1_HASHLEN) {
CTerr(CT_F_SCT_SET0_LOG_ID, 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;
return 1;
}
SCT *SCT_new(void)
{
SCT *sct = OPENSSL_zalloc(sizeof(*sct));
if (sct == NULL) {
CTerr(CT_F_SCT_NEW, ERR_R_MALLOC_FAILURE);
return NULL;
}
sct->entry_type = CT_LOG_ENTRY_TYPE_NOT_SET;
sct->version = SCT_VERSION_NOT_SET;
return sct;
}
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) {
CTerr(CT_F_SCT_SET0_LOG_ID, 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) {
CTerr(CT_F_SCT_SET1_LOG_ID, 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) {
CTerr(CT_F_SCT_SET1_LOG_ID, ERR_R_MALLOC_FAILURE);
return 0;
}
sct->log_id_len = log_id_len;
}
return 1;
}
/*
* Decodes the base64 string |in| into |out|.
* A new string will be malloc'd and assigned to |out|. This will be owned by
* the caller. Do not provide a pre-allocated string in |out|.
*/
static int ct_base64_decode(const char *in, unsigned char **out)
{
size_t inlen = strlen(in);
int outlen, i;
unsigned char *outbuf = NULL;
if (inlen == 0) {
*out = NULL;
return 0;
}
outlen = (inlen / 4) * 3;
outbuf = OPENSSL_malloc(outlen);
if (outbuf == NULL) {
CTerr(CT_F_CT_BASE64_DECODE, ERR_R_MALLOC_FAILURE);
goto err;
}
outlen = EVP_DecodeBlock(outbuf, (unsigned char *)in, inlen);
if (outlen < 0) {
CTerr(CT_F_CT_BASE64_DECODE, CT_R_BASE64_DECODE_ERROR);
goto err;
}
/* Subtract padding bytes from |outlen|. Any more than 2 is malformed. */
i = 0;
while (in[--inlen] == '=') {
--outlen;
if (++i > 2)
goto err;
}
*out = outbuf;
return outlen;
err:
OPENSSL_free(outbuf);
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;
default:
CTerr(CT_F_SCT_SET_LOG_ENTRY_TYPE, CT_R_UNSUPPORTED_ENTRY_TYPE);
return 0;
}
}
int SCT_set1_log_id(SCT *sct, const unsigned char *log_id, size_t log_id_len)
{
/* Currently only SHA-256 allowed so length must be SCT_V1_HASHLEN */
if (log_id_len != SCT_V1_HASHLEN) {
CTerr(CT_F_SCT_SET1_LOG_ID, CT_R_INVALID_LOG_ID_LENGTH);
return 0;
}
OPENSSL_free(sct->log_id);
if (log_id == NULL || log_id_len == 0) {
sct->log_id = NULL;
} else {
sct->log_id = OPENSSL_memdup(log_id, log_id_len);
if (sct->log_id == NULL) {
CTerr(CT_F_SCT_SET1_LOG_ID, ERR_R_MALLOC_FAILURE);
return 0;
}
}
sct->log_id_len = log_id_len;
return 1;
}
int SCT_set1_signature(SCT *sct, const unsigned char *sig, size_t sig_len)
{
OPENSSL_free(sct->sig);
if (sig == NULL || sig_len == 0) {
sct->sig = NULL;
} else {
sct->sig = OPENSSL_memdup(sig, sig_len);
if (sct->sig == NULL) {
CTerr(CT_F_SCT_SET1_SIGNATURE, ERR_R_MALLOC_FAILURE);
return 0;
}
}
sct->sig_len = sig_len;
return 1;
}
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;
if (ext != NULL && ext_len > 0) {
sct->ext = OPENSSL_memdup(ext, ext_len);
if (sct->ext == NULL) {
CTerr(CT_F_SCT_SET1_EXTENSIONS, ERR_R_MALLOC_FAILURE);
return 0;
}
sct->ext_len = ext_len;
}
return 1;
}
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;
return 1;
case NID_ecdsa_with_SHA256:
sct->hash_alg = TLSEXT_hash_sha256;
sct->sig_alg = TLSEXT_signature_ecdsa;
return 1;
default:
CTerr(CT_F_SCT_SET_SIGNATURE_NID, CT_R_UNRECOGNIZED_SIGNATURE_NID);
return 0;
}
}
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) {
CTerr(CT_F_SCT_SET1_SIGNATURE, ERR_R_MALLOC_FAILURE);
return 0;
}
sct->sig_len = sig_len;
}
return 1;
}
SCT *SCT_new_from_base64(unsigned char version, const char *logid_base64,
ct_log_entry_type_t entry_type, uint64_t timestamp,
const char *extensions_base64,
const char *signature_base64)
{
SCT *sct = SCT_new();
unsigned char *dec = NULL;
int declen;
if (sct == NULL) {
CTerr(CT_F_SCT_NEW_FROM_BASE64, ERR_R_MALLOC_FAILURE);
return NULL;
}
/*
* RFC6962 section 4.1 says we "MUST NOT expect this to be 0", but we
* can only construct SCT versions that have been defined.
*/
if (!SCT_set_version(sct, version)) {
CTerr(CT_F_SCT_NEW_FROM_BASE64, CT_R_SCT_UNSUPPORTED_VERSION);
goto err;
}
declen = ct_base64_decode(logid_base64, &dec);
if (declen < 0) {
CTerr(CT_F_SCT_NEW_FROM_BASE64, X509_R_BASE64_DECODE_ERROR);
goto err;
}
if (!SCT_set0_log_id(sct, dec, declen))
goto err;
dec = NULL;
declen = ct_base64_decode(extensions_base64, &dec);
if (declen < 0) {
CTerr(CT_F_SCT_NEW_FROM_BASE64, X509_R_BASE64_DECODE_ERROR);
goto err;
}
SCT_set0_extensions(sct, dec, declen);
dec = NULL;
declen = ct_base64_decode(signature_base64, &dec);
if (declen < 0) {
CTerr(CT_F_SCT_NEW_FROM_BASE64, X509_R_BASE64_DECODE_ERROR);
goto err;
}
if (o2i_SCT_signature(sct, (const unsigned char **)&dec, declen) <= 0)
goto err;
OPENSSL_free(dec);
dec = NULL;
SCT_set_timestamp(sct, timestamp);
if (!SCT_set_log_entry_type(sct, entry_type))
goto err;
return sct;
err:
OPENSSL_free(dec);
SCT_free(sct);
return NULL;
}
SCT *o2i_SCT(SCT **psct, const unsigned char **in, size_t len)
{
SCT *sct = NULL;
const unsigned char *p;
if (len == 0 || len > MAX_SCT_SIZE) {
CTerr(CT_F_O2I_SCT, CT_R_SCT_INVALID);
goto err;
}
if ((sct = SCT_new()) == NULL)
goto err;
p = *in;
sct->version = *p;
if (sct->version == SCT_VERSION_V1) {
int sig_len;
size_t len2;
/*-
* Fixed-length header:
* struct {
* Version sct_version; (1 byte)
* log_id id; (32 bytes)
* uint64 timestamp; (8 bytes)
* CtExtensions extensions; (2 bytes + ?)
* }
*/
if (len < 43) {
CTerr(CT_F_O2I_SCT, CT_R_SCT_INVALID);
goto err;
}
len -= 43;
p++;
sct->log_id = BUF_memdup(p, CT_V1_HASHLEN);
if (sct->log_id == NULL)
goto err;
sct->log_id_len = CT_V1_HASHLEN;
p += CT_V1_HASHLEN;
n2l8(p, sct->timestamp);
n2s(p, len2);
if (len < len2) {
CTerr(CT_F_O2I_SCT, CT_R_SCT_INVALID);
goto err;
}
if (len2 > 0) {
sct->ext = BUF_memdup(p, len2);
if (sct->ext == NULL)
goto err;
}
sct->ext_len = len2;
p += len2;
len -= len2;
sig_len = o2i_SCT_signature(sct, &p, len);
if (sig_len <= 0) {
CTerr(CT_F_O2I_SCT, CT_R_SCT_INVALID);
goto err;
}
len -= sig_len;
*in = p + len;
} else {
/* If not V1 just cache encoding */
sct->sct = BUF_memdup(p, len);
if (sct->sct == NULL)
goto err;
sct->sct_len = len;
*in = p + len;
}
if (psct != NULL) {
SCT_free(*psct);
*psct = sct;
}
return sct;
err:
SCT_free(sct);
return NULL;
}
