providers/implementations/encode_decode/decode_pem2der.c

   1 /*
   2  * Copyright 2020-2022 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 /*
  11  * RSA low level APIs are deprecated for public use, but still ok for
  12  * internal use.
  13  */
  14 #include "internal/deprecated.h"
  15
  16 #include <string.h>
  17
  18 #include <openssl/core_dispatch.h>
  19 #include <openssl/core_names.h>
  20 #include <openssl/core_object.h>
  21 #include <openssl/crypto.h>
  22 #include <openssl/err.h>
  23 #include <openssl/params.h>
  24 #include <openssl/pem.h>
  25 #include <openssl/proverr.h>
  26 #include "internal/nelem.h"
  27 #include "prov/bio.h"
  28 #include "prov/implementations.h"
  29 #include "endecoder_local.h"
  30
  31 static int read_pem(PROV_CTX *provctx, OSSL_CORE_BIO *cin,
  32                     char **pem_name, char **pem_header,
  33                     unsigned char **data, long *len)
  34 {
  35     BIO *in = ossl_bio_new_from_core_bio(provctx, cin);
  36     int ok;
  37
  38     if (in == NULL)
  39         return 0;
  40     ok = (PEM_read_bio(in, pem_name, pem_header, data, len) > 0);
  41
  42     BIO_free(in);
  43     return ok;
  44 }
  45
  46 static OSSL_FUNC_decoder_newctx_fn pem2der_newctx;
  47 static OSSL_FUNC_decoder_freectx_fn pem2der_freectx;
  48 static OSSL_FUNC_decoder_decode_fn pem2der_decode;
  49
  50 /*
  51  * Context used for PEM to DER decoding.
  52  */
  53 struct pem2der_ctx_st {
  54     PROV_CTX *provctx;
  55 };
  56
  57 static void *pem2der_newctx(void *provctx)
  58 {
  59     struct pem2der_ctx_st *ctx = OPENSSL_zalloc(sizeof(*ctx));
  60
  61     if (ctx != NULL)
  62         ctx->provctx = provctx;
  63     return ctx;
  64 }
  65
  66 static void pem2der_freectx(void *vctx)
  67 {
  68     struct pem2der_ctx_st *ctx = vctx;
  69
  70     OPENSSL_free(ctx);
  71 }
  72
  73 /* pem_password_cb compatible function */
  74 struct pem2der_pass_data_st {
  75     OSSL_PASSPHRASE_CALLBACK *cb;
  76     void *cbarg;
  77 };
  78
  79 static int pem2der_pass_helper(char *buf, int num, int w, void *data)
  80 {
  81     struct pem2der_pass_data_st *pass_data = data;
  82     size_t plen;
  83
  84     if (pass_data == NULL
  85         || pass_data->cb == NULL
  86         || !pass_data->cb(buf, num, &plen, NULL, pass_data->cbarg))
  87         return -1;
  88     return (int)plen;
  89 }
  90
  91 /*
  92  * The selection parameter in pem2der_decode() is not used by this function
  93  * because it's not relevant just to decode PEM to DER.
  94  */
  95 static int pem2der_decode(void *vctx, OSSL_CORE_BIO *cin, int selection,
  96                           OSSL_CALLBACK *data_cb, void *data_cbarg,
  97                           OSSL_PASSPHRASE_CALLBACK *pw_cb, void *pw_cbarg)
  98 {
  99     /*
 100      * PEM names we recognise.  Other PEM names should be recognised by
 101      * other decoder implementations.
 102      */
 103     static struct pem_name_map_st {
 104         const char *pem_name;
 105         int object_type;
 106         const char *data_type;
 107         const char *data_structure;
 108     } pem_name_map[] = {
 109         /* PKCS#8 and SubjectPublicKeyInfo */
 110         { PEM_STRING_PKCS8, OSSL_OBJECT_PKEY, NULL, "EncryptedPrivateKeyInfo" },
 111         { PEM_STRING_PKCS8INF, OSSL_OBJECT_PKEY, NULL, "PrivateKeyInfo" },
 112         { PEM_STRING_PUBLIC, OSSL_OBJECT_PKEY, NULL, "SubjectPublicKeyInfo" },
 113
 114         /* Our set of type specific PEM types */
 115         { PEM_STRING_DHPARAMS, OSSL_OBJECT_PKEY, "DH", "type-specific" },
 116         { PEM_STRING_DHXPARAMS, OSSL_OBJECT_PKEY, "X9.42 DH", "type-specific" },
 117         { PEM_STRING_DSA, OSSL_OBJECT_PKEY, "DSA", "type-specific" },
 118         { PEM_STRING_DSA_PUBLIC, OSSL_OBJECT_PKEY, "DSA", "type-specific" },
 119         { PEM_STRING_DSAPARAMS, OSSL_OBJECT_PKEY, "DSA", "type-specific" },
 120         { PEM_STRING_ECPRIVATEKEY, OSSL_OBJECT_PKEY, "EC", "type-specific" },
 121         { PEM_STRING_ECPARAMETERS, OSSL_OBJECT_PKEY, "EC", "type-specific" },
 122         { PEM_STRING_RSA, OSSL_OBJECT_PKEY, "RSA", "type-specific" },
 123         { PEM_STRING_RSA_PUBLIC, OSSL_OBJECT_PKEY, "RSA", "type-specific" },
 124
 125         /*
 126          * A few others that there is at least have an object type for, even
 127          * though there is no provider interface to handle such objects, yet.
 128          * However, this is beneficial for the OSSL_STORE result handler.
 129          */
 130         { PEM_STRING_X509, OSSL_OBJECT_CERT, NULL, "Certificate" },
 131         { PEM_STRING_X509_TRUSTED, OSSL_OBJECT_CERT, NULL, "Certificate" },
 132         { PEM_STRING_X509_OLD, OSSL_OBJECT_CERT, NULL, "Certificate" },
 133         { PEM_STRING_X509_CRL, OSSL_OBJECT_CRL, NULL, "CertificateList" }
 134     };
 135     struct pem2der_ctx_st *ctx = vctx;
 136     char *pem_name = NULL, *pem_header = NULL;
 137     size_t i;
 138     unsigned char *der = NULL;
 139     long der_len = 0;
 140     int ok = 0;
 141     int objtype = OSSL_OBJECT_UNKNOWN;
 142
 143     ok = read_pem(ctx->provctx, cin, &pem_name, &pem_header,
 144                   &der, &der_len) > 0;
 145     /* We return "empty handed".  This is not an error. */
 146     if (!ok)
 147         return 1;
 148
 149     /*
 150      * 10 is the number of characters in "Proc-Type:", which
 151      * PEM_get_EVP_CIPHER_INFO() requires to be present.
 152      * If the PEM header has less characters than that, it's
 153      * not worth spending cycles on it.
 154      */
 155     if (strlen(pem_header) > 10) {
 156         EVP_CIPHER_INFO cipher;
 157         struct pem2der_pass_data_st pass_data;
 158
 159         ok = 0;                  /* Assume that we fail */
 160         pass_data.cb = pw_cb;
 161         pass_data.cbarg = pw_cbarg;
 162         if (!PEM_get_EVP_CIPHER_INFO(pem_header, &cipher)
 163             || !PEM_do_header(&cipher, der, &der_len,
 164                               pem2der_pass_helper, &pass_data))
 165             goto end;
 166     }
 167
 168     /*
 169      * Indicated that we successfully decoded something, or not at all.
 170      * Ending up "empty handed" is not an error.
 171      */
 172     ok = 1;
 173
 174     /* Have a look to see if we recognise anything */
 175     for (i = 0; i < OSSL_NELEM(pem_name_map); i++)
 176         if (strcmp(pem_name, pem_name_map[i].pem_name) == 0)
 177             break;
 178
 179     if (i < OSSL_NELEM(pem_name_map)) {
 180         OSSL_PARAM params[5], *p = params;
 181         /* We expect these to be read only so casting away the const is ok */
 182         char *data_type = (char *)pem_name_map[i].data_type;
 183         char *data_structure = (char *)pem_name_map[i].data_structure;
 184
 185         objtype = pem_name_map[i].object_type;
 186         if (data_type != NULL)
 187             *p++ =
 188                 OSSL_PARAM_construct_utf8_string(OSSL_OBJECT_PARAM_DATA_TYPE,
 189                                                  data_type, 0);
 190
 191         /* We expect this to be read only so casting away the const is ok */
 192         if (data_structure != NULL)
 193             *p++ =
 194                 OSSL_PARAM_construct_utf8_string(OSSL_OBJECT_PARAM_DATA_STRUCTURE,
 195                                                  data_structure, 0);
 196         *p++ =
 197             OSSL_PARAM_construct_octet_string(OSSL_OBJECT_PARAM_DATA,
 198                                               der, der_len);
 199         *p++ =
 200             OSSL_PARAM_construct_int(OSSL_OBJECT_PARAM_TYPE, &objtype);
 201
 202         *p = OSSL_PARAM_construct_end();
 203
 204         ok = data_cb(params, data_cbarg);
 205     }
 206
 207  end:
 208     OPENSSL_free(pem_name);
 209     OPENSSL_free(pem_header);
 210     OPENSSL_free(der);
 211     return ok;
 212 }
 213
 214 const OSSL_DISPATCH ossl_pem_to_der_decoder_functions[] = {
 215     { OSSL_FUNC_DECODER_NEWCTX, (void (*)(void))pem2der_newctx },
 216     { OSSL_FUNC_DECODER_FREECTX, (void (*)(void))pem2der_freectx },
 217     { OSSL_FUNC_DECODER_DECODE, (void (*)(void))pem2der_decode },
 218     { 0, NULL }
 219 };