openssl/crypto/ct/ct_b64.c

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2023-05-09 22:08:48 +00:00
/*
* Copyright 2016 The OpenSSL Project Authors. All Rights Reserved.
*
* Licensed under the OpenSSL license (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
*/
#include <limits.h>
#include <string.h>
#include <openssl/ct.h>
#include <openssl/err.h>
#include <openssl/evp.h>
#include "ct_local.h"
/*
* 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;
}
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;
const unsigned char* p = 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;
}
p = dec;
if (o2i_SCT_signature(sct, &p, 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;
}
/*
* Allocate, build and returns a new |ct_log| from input |pkey_base64|
* It returns 1 on success,
* 0 on decoding failure, or invalid parameter if any
* -1 on internal (malloc) failure
*/
int CTLOG_new_from_base64(CTLOG **ct_log, const char *pkey_base64, const char *name)
{
unsigned char *pkey_der = NULL;
int pkey_der_len;
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;
}
pkey_der_len = ct_base64_decode(pkey_base64, &pkey_der);
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 0;
}
return 1;
}