1 /*
2  * Copyright 1995-2024 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  * We need to use some deprecated APIs
12  */
13 #include "internal/deprecated.h"
14 
15 #include <stdio.h>
16 #include <openssl/buffer.h>
17 #include <openssl/objects.h>
18 #include <openssl/evp.h>
19 #include <openssl/x509.h>
20 #include <openssl/pkcs12.h>
21 #include <openssl/pem.h>
22 #include <openssl/engine.h>
23 #include <openssl/dh.h>
24 #include <openssl/decoder.h>
25 #include <openssl/ui.h>
26 #include "internal/cryptlib.h"
27 #include "internal/passphrase.h"
28 #include "crypto/asn1.h"
29 #include "crypto/x509.h"
30 #include "crypto/evp.h"
31 #include "pem_local.h"
32 
33 int ossl_pem_check_suffix(const char *pem_str, const char *suffix);
34 
pem_read_bio_key_decoder(BIO * bp,EVP_PKEY ** x,pem_password_cb * cb,void * u,OSSL_LIB_CTX * libctx,const char * propq,int selection)35 static EVP_PKEY *pem_read_bio_key_decoder(BIO *bp, EVP_PKEY **x,
36                                           pem_password_cb *cb, void *u,
37                                           OSSL_LIB_CTX *libctx,
38                                           const char *propq,
39                                           int selection)
40 {
41     EVP_PKEY *pkey = NULL;
42     OSSL_DECODER_CTX *dctx = NULL;
43     int pos, newpos;
44 
45     if ((pos = BIO_tell(bp)) < 0)
46         /* We can depend on BIO_tell() thanks to the BIO_f_readbuffer() */
47         return NULL;
48 
49     dctx = OSSL_DECODER_CTX_new_for_pkey(&pkey, "PEM", NULL, NULL,
50                                          selection, libctx, propq);
51 
52     if (dctx == NULL)
53         return NULL;
54 
55     if (cb == NULL)
56         cb = PEM_def_callback;
57 
58     if (!OSSL_DECODER_CTX_set_pem_password_cb(dctx, cb, u))
59         goto err;
60 
61     ERR_set_mark();
62     while (!OSSL_DECODER_from_bio(dctx, bp) || pkey == NULL)
63         if (BIO_eof(bp) != 0 || (newpos = BIO_tell(bp)) < 0 || newpos <= pos) {
64             ERR_clear_last_mark();
65             goto err;
66         } else {
67             if (ERR_GET_REASON(ERR_peek_error()) == ERR_R_UNSUPPORTED) {
68                 /* unsupported PEM data, try again */
69                 ERR_pop_to_mark();
70                 ERR_set_mark();
71             } else {
72                 /* other error, bail out */
73                 ERR_clear_last_mark();
74                 goto err;
75             }
76             pos = newpos;
77         }
78     ERR_pop_to_mark();
79 
80     /* if we were asked for private key, the public key is optional */
81     if ((selection & OSSL_KEYMGMT_SELECT_PRIVATE_KEY) != 0)
82         selection = selection & ~OSSL_KEYMGMT_SELECT_PUBLIC_KEY;
83 
84     if (!evp_keymgmt_util_has(pkey, selection)) {
85         EVP_PKEY_free(pkey);
86         pkey = NULL;
87         ERR_raise(ERR_LIB_PEM, PEM_R_UNSUPPORTED_KEY_COMPONENTS);
88         goto err;
89     }
90 
91     if (x != NULL) {
92         EVP_PKEY_free(*x);
93         *x = pkey;
94     }
95 
96  err:
97     OSSL_DECODER_CTX_free(dctx);
98     return pkey;
99 }
100 
pem_read_bio_key_legacy(BIO * bp,EVP_PKEY ** x,pem_password_cb * cb,void * u,OSSL_LIB_CTX * libctx,const char * propq,int selection)101 static EVP_PKEY *pem_read_bio_key_legacy(BIO *bp, EVP_PKEY **x,
102                                          pem_password_cb *cb, void *u,
103                                          OSSL_LIB_CTX *libctx,
104                                          const char *propq,
105                                          int selection)
106 {
107     char *nm = NULL;
108     const unsigned char *p = NULL;
109     unsigned char *data = NULL;
110     long len;
111     int slen;
112     EVP_PKEY *ret = NULL;
113 
114     ERR_set_mark();  /* not interested in PEM read errors */
115     if ((selection & OSSL_KEYMGMT_SELECT_PRIVATE_KEY) != 0) {
116         if (!PEM_bytes_read_bio_secmem(&data, &len, &nm,
117                                        PEM_STRING_EVP_PKEY,
118                                        bp, cb, u)) {
119             ERR_pop_to_mark();
120             return NULL;
121          }
122     } else {
123         const char *pem_string = PEM_STRING_PARAMETERS;
124 
125         if ((selection & OSSL_KEYMGMT_SELECT_PUBLIC_KEY) != 0)
126             pem_string = PEM_STRING_PUBLIC;
127         if (!PEM_bytes_read_bio(&data, &len, &nm,
128                                 pem_string,
129                                 bp, cb, u)) {
130             ERR_pop_to_mark();
131             return NULL;
132         }
133     }
134     ERR_clear_last_mark();
135     p = data;
136 
137     if (strcmp(nm, PEM_STRING_PKCS8INF) == 0) {
138         PKCS8_PRIV_KEY_INFO *p8inf;
139 
140         if ((p8inf = d2i_PKCS8_PRIV_KEY_INFO(NULL, &p, len)) == NULL)
141             goto p8err;
142         ret = evp_pkcs82pkey_legacy(p8inf, libctx, propq);
143         if (x != NULL) {
144             EVP_PKEY_free(*x);
145             *x = ret;
146         }
147         PKCS8_PRIV_KEY_INFO_free(p8inf);
148     } else if (strcmp(nm, PEM_STRING_PKCS8) == 0) {
149         PKCS8_PRIV_KEY_INFO *p8inf;
150         X509_SIG *p8;
151         int klen;
152         char psbuf[PEM_BUFSIZE];
153 
154         if ((p8 = d2i_X509_SIG(NULL, &p, len)) == NULL)
155             goto p8err;
156         if (cb != NULL)
157             klen = cb(psbuf, PEM_BUFSIZE, 0, u);
158         else
159             klen = PEM_def_callback(psbuf, PEM_BUFSIZE, 0, u);
160         if (klen < 0) {
161             ERR_raise(ERR_LIB_PEM, PEM_R_BAD_PASSWORD_READ);
162             X509_SIG_free(p8);
163             goto err;
164         }
165         p8inf = PKCS8_decrypt(p8, psbuf, klen);
166         X509_SIG_free(p8);
167         OPENSSL_cleanse(psbuf, klen);
168         if (p8inf == NULL)
169             goto p8err;
170         ret = evp_pkcs82pkey_legacy(p8inf, libctx, propq);
171         if (x != NULL) {
172             EVP_PKEY_free(*x);
173             *x = ret;
174         }
175         PKCS8_PRIV_KEY_INFO_free(p8inf);
176     } else if ((slen = ossl_pem_check_suffix(nm, "PRIVATE KEY")) > 0) {
177         const EVP_PKEY_ASN1_METHOD *ameth;
178         ameth = EVP_PKEY_asn1_find_str(NULL, nm, slen);
179         if (ameth == NULL || ameth->old_priv_decode == NULL)
180             goto p8err;
181         ret = ossl_d2i_PrivateKey_legacy(ameth->pkey_id, x, &p, len, libctx,
182                                          propq);
183     } else if ((selection & OSSL_KEYMGMT_SELECT_PRIVATE_KEY) == 0
184                && (selection & OSSL_KEYMGMT_SELECT_PUBLIC_KEY) != 0) {
185         /* Trying legacy PUBKEY decoding only if we do not want private key. */
186         ret = ossl_d2i_PUBKEY_legacy(x, &p, len);
187     } else if ((selection & EVP_PKEY_KEYPAIR) == 0
188                && (slen = ossl_pem_check_suffix(nm, "PARAMETERS")) > 0) {
189         /* Trying legacy params decoding only if we do not want a key. */
190         ret = EVP_PKEY_new();
191         if (ret == NULL)
192             goto err;
193         if (!EVP_PKEY_set_type_str(ret, nm, slen)
194             || !ret->ameth->param_decode
195             || !ret->ameth->param_decode(ret, &p, len)) {
196             EVP_PKEY_free(ret);
197             ret = NULL;
198             goto err;
199         }
200         if (x) {
201             EVP_PKEY_free(*x);
202             *x = ret;
203         }
204     }
205 
206  p8err:
207     if (ret == NULL && ERR_peek_last_error() == 0)
208         /* ensure some error is reported but do not hide the real one */
209         ERR_raise(ERR_LIB_PEM, ERR_R_ASN1_LIB);
210  err:
211     OPENSSL_secure_free(nm);
212     OPENSSL_secure_clear_free(data, len);
213     return ret;
214 }
215 
pem_read_bio_key(BIO * bp,EVP_PKEY ** x,pem_password_cb * cb,void * u,OSSL_LIB_CTX * libctx,const char * propq,int selection)216 static EVP_PKEY *pem_read_bio_key(BIO *bp, EVP_PKEY **x,
217                                   pem_password_cb *cb, void *u,
218                                   OSSL_LIB_CTX *libctx,
219                                   const char *propq,
220                                   int selection)
221 {
222     EVP_PKEY *ret = NULL;
223     BIO *new_bio = NULL;
224     int pos;
225     struct ossl_passphrase_data_st pwdata = { 0 };
226 
227     if ((pos = BIO_tell(bp)) < 0) {
228         new_bio = BIO_new(BIO_f_readbuffer());
229         if (new_bio == NULL)
230             return NULL;
231         bp = BIO_push(new_bio, bp);
232         pos = BIO_tell(bp);
233     }
234 
235     if (cb == NULL)
236         cb = PEM_def_callback;
237 
238     if (!ossl_pw_set_pem_password_cb(&pwdata, cb, u)
239         || !ossl_pw_enable_passphrase_caching(&pwdata))
240         goto err;
241 
242     ERR_set_mark();
243     ret = pem_read_bio_key_decoder(bp, x, ossl_pw_pem_password, &pwdata,
244                                    libctx, propq, selection);
245     if (ret == NULL
246         && (BIO_seek(bp, pos) < 0
247             || (ret = pem_read_bio_key_legacy(bp, x,
248                                               ossl_pw_pem_password, &pwdata,
249                                               libctx, propq,
250                                               selection)) == NULL))
251         ERR_clear_last_mark();
252     else
253         ERR_pop_to_mark();
254 
255  err:
256     ossl_pw_clear_passphrase_data(&pwdata);
257     if (new_bio != NULL) {
258         BIO_pop(new_bio);
259         BIO_free(new_bio);
260     }
261     return ret;
262 }
263 
PEM_read_bio_PUBKEY_ex(BIO * bp,EVP_PKEY ** x,pem_password_cb * cb,void * u,OSSL_LIB_CTX * libctx,const char * propq)264 EVP_PKEY *PEM_read_bio_PUBKEY_ex(BIO *bp, EVP_PKEY **x,
265                                  pem_password_cb *cb, void *u,
266                                  OSSL_LIB_CTX *libctx, const char *propq)
267 {
268     return pem_read_bio_key(bp, x, cb, u, libctx, propq,
269                             EVP_PKEY_PUBLIC_KEY);
270 }
271 
PEM_read_bio_PUBKEY(BIO * bp,EVP_PKEY ** x,pem_password_cb * cb,void * u)272 EVP_PKEY *PEM_read_bio_PUBKEY(BIO *bp, EVP_PKEY **x, pem_password_cb *cb,
273                               void *u)
274 {
275     return PEM_read_bio_PUBKEY_ex(bp, x, cb, u, NULL, NULL);
276 }
277 
278 #ifndef OPENSSL_NO_STDIO
PEM_read_PUBKEY_ex(FILE * fp,EVP_PKEY ** x,pem_password_cb * cb,void * u,OSSL_LIB_CTX * libctx,const char * propq)279 EVP_PKEY *PEM_read_PUBKEY_ex(FILE *fp, EVP_PKEY **x,
280                              pem_password_cb *cb, void *u,
281                              OSSL_LIB_CTX *libctx, const char *propq)
282 {
283     BIO *b;
284     EVP_PKEY *ret;
285 
286     if ((b = BIO_new(BIO_s_file())) == NULL) {
287         ERR_raise(ERR_LIB_PEM, ERR_R_BUF_LIB);
288         return 0;
289     }
290     BIO_set_fp(b, fp, BIO_NOCLOSE);
291     ret = PEM_read_bio_PUBKEY_ex(b, x, cb, u, libctx, propq);
292     BIO_free(b);
293     return ret;
294 }
295 
PEM_read_PUBKEY(FILE * fp,EVP_PKEY ** x,pem_password_cb * cb,void * u)296 EVP_PKEY *PEM_read_PUBKEY(FILE *fp, EVP_PKEY **x, pem_password_cb *cb, void *u)
297 {
298     return PEM_read_PUBKEY_ex(fp, x, cb, u, NULL, NULL);
299 }
300 #endif
301 
PEM_read_bio_PrivateKey_ex(BIO * bp,EVP_PKEY ** x,pem_password_cb * cb,void * u,OSSL_LIB_CTX * libctx,const char * propq)302 EVP_PKEY *PEM_read_bio_PrivateKey_ex(BIO *bp, EVP_PKEY **x,
303                                      pem_password_cb *cb, void *u,
304                                      OSSL_LIB_CTX *libctx, const char *propq)
305 {
306     return pem_read_bio_key(bp, x, cb, u, libctx, propq,
307                             /* we also want the public key, if available */
308                             EVP_PKEY_KEYPAIR);
309 }
310 
PEM_read_bio_PrivateKey(BIO * bp,EVP_PKEY ** x,pem_password_cb * cb,void * u)311 EVP_PKEY *PEM_read_bio_PrivateKey(BIO *bp, EVP_PKEY **x, pem_password_cb *cb,
312                                   void *u)
313 {
314     return PEM_read_bio_PrivateKey_ex(bp, x, cb, u, NULL, NULL);
315 }
316 
PEM_write_cb_ex_fnsig(PrivateKey,EVP_PKEY,BIO,write_bio)317 PEM_write_cb_ex_fnsig(PrivateKey, EVP_PKEY, BIO, write_bio)
318 {
319     IMPLEMENT_PEM_provided_write_body_vars(pkey, PrivateKey, propq);
320 
321     IMPLEMENT_PEM_provided_write_body_pass();
322     IMPLEMENT_PEM_provided_write_body_main(pkey, bio);
323 
324  legacy:
325     if (x != NULL && (x->ameth == NULL || x->ameth->priv_encode != NULL))
326         return PEM_write_bio_PKCS8PrivateKey(out, x, enc,
327                                              (const char *)kstr, klen, cb, u);
328     return PEM_write_bio_PrivateKey_traditional(out, x, enc, kstr, klen, cb, u);
329 }
330 
PEM_write_cb_fnsig(PrivateKey,EVP_PKEY,BIO,write_bio)331 PEM_write_cb_fnsig(PrivateKey, EVP_PKEY, BIO, write_bio)
332 {
333     return PEM_write_bio_PrivateKey_ex(out, x, enc, kstr, klen, cb, u,
334                                        NULL, NULL);
335 }
336 
337 /*
338  * Note: there is no way to tell a provided pkey encoder to use "traditional"
339  * encoding.  Therefore, if the pkey is provided, we try to take a copy
340  */
PEM_write_bio_PrivateKey_traditional(BIO * bp,const EVP_PKEY * x,const EVP_CIPHER * enc,const unsigned char * kstr,int klen,pem_password_cb * cb,void * u)341 int PEM_write_bio_PrivateKey_traditional(BIO *bp, const EVP_PKEY *x,
342                                          const EVP_CIPHER *enc,
343                                          const unsigned char *kstr, int klen,
344                                          pem_password_cb *cb, void *u)
345 {
346     char pem_str[80];
347     EVP_PKEY *copy = NULL;
348     int ret;
349 
350     if (x == NULL)
351         return 0;
352 
353     if (evp_pkey_is_assigned(x)
354         && evp_pkey_is_provided(x)
355         && evp_pkey_copy_downgraded(&copy, x))
356         x = copy;
357 
358     if (x->ameth == NULL || x->ameth->old_priv_encode == NULL) {
359         ERR_raise(ERR_LIB_PEM, PEM_R_UNSUPPORTED_PUBLIC_KEY_TYPE);
360         EVP_PKEY_free(copy);
361         return 0;
362     }
363     BIO_snprintf(pem_str, 80, "%s PRIVATE KEY", x->ameth->pem_str);
364     ret = PEM_ASN1_write_bio((i2d_of_void *)i2d_PrivateKey,
365                              pem_str, bp, x, enc, kstr, klen, cb, u);
366 
367     EVP_PKEY_free(copy);
368     return ret;
369 }
370 
no_password_cb(char * buf,int num,int rwflag,void * userdata)371 static int no_password_cb(char *buf, int num, int rwflag, void *userdata)
372 {
373     return -1;
374 }
375 
PEM_read_bio_Parameters_ex(BIO * bp,EVP_PKEY ** x,OSSL_LIB_CTX * libctx,const char * propq)376 EVP_PKEY *PEM_read_bio_Parameters_ex(BIO *bp, EVP_PKEY **x,
377                                      OSSL_LIB_CTX *libctx, const char *propq)
378 {
379     /*
380      * PEM_read_bio_Parameters(_ex) should never ask for a password. Any attempt
381      * to get a password just fails.
382      */
383     return pem_read_bio_key(bp, x, no_password_cb, NULL, libctx, propq,
384                             EVP_PKEY_KEY_PARAMETERS);
385 }
386 
PEM_read_bio_Parameters(BIO * bp,EVP_PKEY ** x)387 EVP_PKEY *PEM_read_bio_Parameters(BIO *bp, EVP_PKEY **x)
388 {
389     return PEM_read_bio_Parameters_ex(bp, x, NULL, NULL);
390 }
391 
PEM_write_fnsig(Parameters,EVP_PKEY,BIO,write_bio)392 PEM_write_fnsig(Parameters, EVP_PKEY, BIO, write_bio)
393 {
394     char pem_str[80];
395     IMPLEMENT_PEM_provided_write_body_vars(pkey, Parameters, NULL);
396 
397     IMPLEMENT_PEM_provided_write_body_main(pkey, bio);
398 
399  legacy:
400     if (!x->ameth || !x->ameth->param_encode)
401         return 0;
402 
403     BIO_snprintf(pem_str, 80, "%s PARAMETERS", x->ameth->pem_str);
404     return PEM_ASN1_write_bio((i2d_of_void *)x->ameth->param_encode,
405                               pem_str, out, x, NULL, NULL, 0, 0, NULL);
406 }
407 
408 #ifndef OPENSSL_NO_STDIO
PEM_read_PrivateKey_ex(FILE * fp,EVP_PKEY ** x,pem_password_cb * cb,void * u,OSSL_LIB_CTX * libctx,const char * propq)409 EVP_PKEY *PEM_read_PrivateKey_ex(FILE *fp, EVP_PKEY **x, pem_password_cb *cb,
410                                  void *u, OSSL_LIB_CTX *libctx,
411                                  const char *propq)
412 {
413     BIO *b;
414     EVP_PKEY *ret;
415 
416     if ((b = BIO_new(BIO_s_file())) == NULL) {
417         ERR_raise(ERR_LIB_PEM, ERR_R_BUF_LIB);
418         return 0;
419     }
420     BIO_set_fp(b, fp, BIO_NOCLOSE);
421     ret = PEM_read_bio_PrivateKey_ex(b, x, cb, u, libctx, propq);
422     BIO_free(b);
423     return ret;
424 }
425 
PEM_read_PrivateKey(FILE * fp,EVP_PKEY ** x,pem_password_cb * cb,void * u)426 EVP_PKEY *PEM_read_PrivateKey(FILE *fp, EVP_PKEY **x, pem_password_cb *cb,
427                               void *u)
428 {
429     return PEM_read_PrivateKey_ex(fp, x, cb, u, NULL, NULL);
430 }
431 
PEM_write_cb_ex_fnsig(PrivateKey,EVP_PKEY,FILE,write)432 PEM_write_cb_ex_fnsig(PrivateKey, EVP_PKEY, FILE, write)
433 {
434     BIO *b;
435     int ret;
436 
437     if ((b = BIO_new_fp(out, BIO_NOCLOSE)) == NULL) {
438         ERR_raise(ERR_LIB_PEM, ERR_R_BUF_LIB);
439         return 0;
440     }
441     ret = PEM_write_bio_PrivateKey_ex(b, x, enc, kstr, klen, cb, u,
442                                       libctx, propq);
443     BIO_free(b);
444     return ret;
445 }
446 
PEM_write_cb_fnsig(PrivateKey,EVP_PKEY,FILE,write)447 PEM_write_cb_fnsig(PrivateKey, EVP_PKEY, FILE, write)
448 {
449     return PEM_write_PrivateKey_ex(out, x, enc, kstr, klen, cb, u, NULL, NULL);
450 }
451 #endif
452