crypto/ct/ct_b64.c

   1 /*
   2  * Copyright 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 <limits.h>
  11 #include <string.h>
  12
  13 #include <openssl/ct.h>
  14 #include <openssl/err.h>
  15 #include <openssl/evp.h>
  16
  17 #include "ct_locl.h"
  18
  19 /*
  20  * Decodes the base64 string |in| into |out|.
  21  * A new string will be malloc'd and assigned to |out|. This will be owned by
  22  * the caller. Do not provide a pre-allocated string in |out|.
  23  */
  24 static int ct_base64_decode(const char *in, unsigned char **out)
  25 {
  26     size_t inlen = strlen(in);
  27     int outlen;
  28     unsigned char *outbuf = NULL;
  29
  30     if (inlen == 0) {
  31         *out = NULL;
  32         return 0;
  33     }
  34
  35     outlen = (inlen / 4) * 3;
  36     outbuf = OPENSSL_malloc(outlen);
  37     if (outbuf == NULL) {
  38         CTerr(CT_F_CT_BASE64_DECODE, ERR_R_MALLOC_FAILURE);
  39         goto err;
  40     }
  41
  42     outlen = EVP_DecodeBlock(outbuf, (unsigned char *)in, inlen);
  43     if (outlen < 0) {
  44         CTerr(CT_F_CT_BASE64_DECODE, CT_R_BASE64_DECODE_ERROR);
  45         goto err;
  46     }
  47
  48     *out = outbuf;
  49     return outlen;
  50 err:
  51     OPENSSL_free(outbuf);
  52     return -1;
  53 }
  54
  55 SCT *SCT_new_from_base64(unsigned char version, const char *logid_base64,
  56                          ct_log_entry_type_t entry_type, uint64_t timestamp,
  57                          const char *extensions_base64,
  58                          const char *signature_base64)
  59 {
  60     SCT *sct = SCT_new();
  61     unsigned char *dec = NULL;
  62     int declen;
  63
  64     if (sct == NULL) {
  65         CTerr(CT_F_SCT_NEW_FROM_BASE64, ERR_R_MALLOC_FAILURE);
  66         return NULL;
  67     }
  68
  69     /*
  70      * RFC6962 section 4.1 says we "MUST NOT expect this to be 0", but we
  71      * can only construct SCT versions that have been defined.
  72      */
  73     if (!SCT_set_version(sct, version)) {
  74         CTerr(CT_F_SCT_NEW_FROM_BASE64, CT_R_SCT_UNSUPPORTED_VERSION);
  75         goto err;
  76     }
  77
  78     declen = ct_base64_decode(logid_base64, &dec);
  79     if (declen < 0) {
  80         CTerr(CT_F_SCT_NEW_FROM_BASE64, X509_R_BASE64_DECODE_ERROR);
  81         goto err;
  82     }
  83     if (!SCT_set0_log_id(sct, dec, declen))
  84         goto err;
  85     dec = NULL;
  86
  87     declen = ct_base64_decode(extensions_base64, &dec);
  88     if (declen < 0) {
  89         CTerr(CT_F_SCT_NEW_FROM_BASE64, X509_R_BASE64_DECODE_ERROR);
  90         goto err;
  91     }
  92     SCT_set0_extensions(sct, dec, declen);
  93     dec = NULL;
  94
  95     declen = ct_base64_decode(signature_base64, &dec);
  96     if (declen < 0) {
  97         CTerr(CT_F_SCT_NEW_FROM_BASE64, X509_R_BASE64_DECODE_ERROR);
  98         goto err;
  99     }
 100     if (o2i_SCT_signature(sct, (const unsigned char **)&dec, declen) <= 0)
 101         goto err;
 102     OPENSSL_free(dec);
 103     dec = NULL;
 104
 105     SCT_set_timestamp(sct, timestamp);
 106
 107     if (!SCT_set_log_entry_type(sct, entry_type))
 108         goto err;
 109
 110     return sct;
 111
 112  err:
 113     OPENSSL_free(dec);
 114     SCT_free(sct);
 115     return NULL;
 116 }
 117
 118 CTLOG *CTLOG_new_from_base64(const char *pkey_base64, const char *name)
 119 {
 120     unsigned char *pkey_der = NULL;
 121     int pkey_der_len = ct_base64_decode(pkey_base64, &pkey_der);
 122     const unsigned char *p;
 123     EVP_PKEY *pkey = NULL;
 124     CTLOG *log = NULL;
 125
 126     if (pkey_der_len <= 0) {
 127         CTerr(CT_F_CTLOG_NEW_FROM_BASE64, CT_R_LOG_CONF_INVALID_KEY);
 128         return NULL;
 129     }
 130
 131     p = pkey_der;
 132     pkey = d2i_PUBKEY(NULL, &p, pkey_der_len);
 133     OPENSSL_free(pkey_der);
 134     if (pkey == NULL) {
 135         CTerr(CT_F_CTLOG_NEW_FROM_BASE64, CT_R_LOG_CONF_INVALID_KEY);
 136         return NULL;
 137     }
 138
 139     log = CTLOG_new(pkey, name);
 140     if (log == NULL) {
 141         EVP_PKEY_free(pkey);
 142         return NULL;
 143     }
 144
 145     return log;
 146 }