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      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 };
    220