xref: /freebsd/crypto/openssl/crypto/pem/pem_pkey.c (revision f25b8c9fb4f58cf61adb47d7570abe7caa6d385d)
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 /* We need to use some deprecated APIs */
11 #define OPENSSL_SUPPRESS_DEPRECATED
12 
13 #include <stdio.h>
14 #include <openssl/buffer.h>
15 #include <openssl/objects.h>
16 #include <openssl/evp.h>
17 #include <openssl/x509.h>
18 #include <openssl/pkcs12.h>
19 #include <openssl/pem.h>
20 #include <openssl/engine.h>
21 #include <openssl/dh.h>
22 #include <openssl/decoder.h>
23 #include <openssl/ui.h>
24 #include "internal/cryptlib.h"
25 #include "internal/passphrase.h"
26 #include "crypto/asn1.h"
27 #include "crypto/x509.h"
28 #include "crypto/evp.h"
29 #include "pem_local.h"
30 
31 int ossl_pem_check_suffix(const char *pem_str, const char *suffix);
32 
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)33 static EVP_PKEY *pem_read_bio_key_decoder(BIO *bp, EVP_PKEY **x,
34     pem_password_cb *cb, void *u,
35     OSSL_LIB_CTX *libctx,
36     const char *propq,
37     int selection)
38 {
39     EVP_PKEY *pkey = NULL;
40     OSSL_DECODER_CTX *dctx = NULL;
41     int pos, newpos;
42 
43     if ((pos = BIO_tell(bp)) < 0)
44         /* We can depend on BIO_tell() thanks to the BIO_f_readbuffer() */
45         return NULL;
46 
47     dctx = OSSL_DECODER_CTX_new_for_pkey(&pkey, "PEM", NULL, NULL,
48         selection, libctx, propq);
49 
50     if (dctx == NULL)
51         return NULL;
52 
53     if (cb == NULL)
54         cb = PEM_def_callback;
55 
56     if (!OSSL_DECODER_CTX_set_pem_password_cb(dctx, cb, u))
57         goto err;
58 
59     ERR_set_mark();
60     while (!OSSL_DECODER_from_bio(dctx, bp) || pkey == NULL)
61         if (BIO_eof(bp) != 0 || (newpos = BIO_tell(bp)) < 0 || newpos <= pos) {
62             ERR_clear_last_mark();
63             goto err;
64         } else {
65             if (ERR_GET_REASON(ERR_peek_error()) == ERR_R_UNSUPPORTED) {
66                 /* unsupported PEM data, try again */
67                 ERR_pop_to_mark();
68                 ERR_set_mark();
69             } else {
70                 /* other error, bail out */
71                 ERR_clear_last_mark();
72                 goto err;
73             }
74             pos = newpos;
75         }
76     ERR_pop_to_mark();
77 
78     /* if we were asked for private key, the public key is optional */
79     if ((selection & OSSL_KEYMGMT_SELECT_PRIVATE_KEY) != 0)
80         selection = selection & ~OSSL_KEYMGMT_SELECT_PUBLIC_KEY;
81 
82     if (!evp_keymgmt_util_has(pkey, selection)) {
83         EVP_PKEY_free(pkey);
84         pkey = NULL;
85         ERR_raise(ERR_LIB_PEM, PEM_R_UNSUPPORTED_KEY_COMPONENTS);
86         goto err;
87     }
88 
89     if (x != NULL) {
90         EVP_PKEY_free(*x);
91         *x = pkey;
92     }
93 
94 err:
95     OSSL_DECODER_CTX_free(dctx);
96     return pkey;
97 }
98 
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)99 static EVP_PKEY *pem_read_bio_key_legacy(BIO *bp, EVP_PKEY **x,
100     pem_password_cb *cb, void *u,
101     OSSL_LIB_CTX *libctx,
102     const char *propq,
103     int selection)
104 {
105     char *nm = NULL;
106     const unsigned char *p = NULL;
107     unsigned char *data = NULL;
108     long len;
109     int slen;
110     EVP_PKEY *ret = NULL;
111 
112     ERR_set_mark(); /* not interested in PEM read errors */
113     if ((selection & OSSL_KEYMGMT_SELECT_PRIVATE_KEY) != 0) {
114         if (!PEM_bytes_read_bio_secmem(&data, &len, &nm,
115                 PEM_STRING_EVP_PKEY,
116                 bp, cb, u)) {
117             ERR_pop_to_mark();
118             return NULL;
119         }
120     } else {
121         const char *pem_string = PEM_STRING_PARAMETERS;
122 
123         if ((selection & OSSL_KEYMGMT_SELECT_PUBLIC_KEY) != 0)
124             pem_string = PEM_STRING_PUBLIC;
125         if (!PEM_bytes_read_bio(&data, &len, &nm,
126                 pem_string,
127                 bp, cb, u)) {
128             ERR_pop_to_mark();
129             return NULL;
130         }
131     }
132     ERR_clear_last_mark();
133     p = data;
134 
135     if (strcmp(nm, PEM_STRING_PKCS8INF) == 0) {
136         PKCS8_PRIV_KEY_INFO *p8inf;
137 
138         if ((p8inf = d2i_PKCS8_PRIV_KEY_INFO(NULL, &p, len)) == NULL)
139             goto p8err;
140         ret = evp_pkcs82pkey_legacy(p8inf, libctx, propq);
141         if (x != NULL) {
142             EVP_PKEY_free(*x);
143             *x = ret;
144         }
145         PKCS8_PRIV_KEY_INFO_free(p8inf);
146     } else if (strcmp(nm, PEM_STRING_PKCS8) == 0) {
147         PKCS8_PRIV_KEY_INFO *p8inf;
148         X509_SIG *p8;
149         int klen;
150         char psbuf[PEM_BUFSIZE];
151 
152         if ((p8 = d2i_X509_SIG(NULL, &p, len)) == NULL)
153             goto p8err;
154         if (cb != NULL)
155             klen = cb(psbuf, PEM_BUFSIZE, 0, u);
156         else
157             klen = PEM_def_callback(psbuf, PEM_BUFSIZE, 0, u);
158         if (klen < 0) {
159             ERR_raise(ERR_LIB_PEM, PEM_R_BAD_PASSWORD_READ);
160             X509_SIG_free(p8);
161             goto err;
162         }
163         p8inf = PKCS8_decrypt(p8, psbuf, klen);
164         X509_SIG_free(p8);
165         OPENSSL_cleanse(psbuf, klen);
166         if (p8inf == NULL)
167             goto p8err;
168         ret = evp_pkcs82pkey_legacy(p8inf, libctx, propq);
169         if (x != NULL) {
170             EVP_PKEY_free(*x);
171             *x = ret;
172         }
173         PKCS8_PRIV_KEY_INFO_free(p8inf);
174     } else if ((slen = ossl_pem_check_suffix(nm, "PRIVATE KEY")) > 0) {
175         const EVP_PKEY_ASN1_METHOD *ameth;
176         ameth = EVP_PKEY_asn1_find_str(NULL, nm, slen);
177         if (ameth == NULL || ameth->old_priv_decode == NULL)
178             goto p8err;
179         ret = ossl_d2i_PrivateKey_legacy(ameth->pkey_id, x, &p, len, libctx,
180             propq);
181     } else if ((selection & OSSL_KEYMGMT_SELECT_PRIVATE_KEY) == 0
182         && (selection & OSSL_KEYMGMT_SELECT_PUBLIC_KEY) != 0) {
183         /* Trying legacy PUBKEY decoding only if we do not want private key. */
184         ret = ossl_d2i_PUBKEY_legacy(x, &p, len);
185     } else if ((selection & EVP_PKEY_KEYPAIR) == 0
186         && (slen = ossl_pem_check_suffix(nm, "PARAMETERS")) > 0) {
187         /* Trying legacy params decoding only if we do not want a key. */
188         ret = EVP_PKEY_new();
189         if (ret == NULL)
190             goto err;
191         if (!EVP_PKEY_set_type_str(ret, nm, slen)
192             || !ret->ameth->param_decode
193             || !ret->ameth->param_decode(ret, &p, len)) {
194             EVP_PKEY_free(ret);
195             ret = NULL;
196             goto err;
197         }
198         if (x) {
199             EVP_PKEY_free(*x);
200             *x = ret;
201         }
202     }
203 
204 p8err:
205     if (ret == NULL && ERR_peek_last_error() == 0)
206         /* ensure some error is reported but do not hide the real one */
207         ERR_raise(ERR_LIB_PEM, ERR_R_ASN1_LIB);
208 err:
209     OPENSSL_secure_free(nm);
210     OPENSSL_secure_clear_free(data, len);
211     return ret;
212 }
213 
pem_read_bio_key(BIO * bp,EVP_PKEY ** x,pem_password_cb * cb,void * u,OSSL_LIB_CTX * libctx,const char * propq,int selection)214 static EVP_PKEY *pem_read_bio_key(BIO *bp, EVP_PKEY **x,
215     pem_password_cb *cb, void *u,
216     OSSL_LIB_CTX *libctx,
217     const char *propq,
218     int selection)
219 {
220     EVP_PKEY *ret = NULL;
221     BIO *new_bio = NULL;
222     int pos;
223     struct ossl_passphrase_data_st pwdata = { 0 };
224 
225     if ((pos = BIO_tell(bp)) < 0) {
226         new_bio = BIO_new(BIO_f_readbuffer());
227         if (new_bio == NULL)
228             return NULL;
229         bp = BIO_push(new_bio, bp);
230         pos = BIO_tell(bp);
231     }
232 
233     if (cb == NULL)
234         cb = PEM_def_callback;
235 
236     if (!ossl_pw_set_pem_password_cb(&pwdata, cb, u)
237         || !ossl_pw_enable_passphrase_caching(&pwdata))
238         goto err;
239 
240     ERR_set_mark();
241     ret = pem_read_bio_key_decoder(bp, x, ossl_pw_pem_password, &pwdata,
242         libctx, propq, selection);
243     if (ret == NULL
244         && (BIO_seek(bp, pos) < 0
245             || (ret = pem_read_bio_key_legacy(bp, x,
246                     ossl_pw_pem_password, &pwdata,
247                     libctx, propq,
248                     selection))
249                 == NULL))
250         ERR_clear_last_mark();
251     else
252         ERR_pop_to_mark();
253 
254 err:
255     ossl_pw_clear_passphrase_data(&pwdata);
256     if (new_bio != NULL) {
257         BIO_pop(new_bio);
258         BIO_free(new_bio);
259     }
260     return ret;
261 }
262 
PEM_read_bio_PUBKEY_ex(BIO * bp,EVP_PKEY ** x,pem_password_cb * cb,void * u,OSSL_LIB_CTX * libctx,const char * propq)263 EVP_PKEY *PEM_read_bio_PUBKEY_ex(BIO *bp, EVP_PKEY **x,
264     pem_password_cb *cb, void *u,
265     OSSL_LIB_CTX *libctx, const char *propq)
266 {
267     return pem_read_bio_key(bp, x, cb, u, libctx, propq,
268         EVP_PKEY_PUBLIC_KEY);
269 }
270 
PEM_read_bio_PUBKEY(BIO * bp,EVP_PKEY ** x,pem_password_cb * cb,void * u)271 EVP_PKEY *PEM_read_bio_PUBKEY(BIO *bp, EVP_PKEY **x, pem_password_cb *cb,
272     void *u)
273 {
274     return PEM_read_bio_PUBKEY_ex(bp, x, cb, u, NULL, NULL);
275 }
276 
277 #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)278 EVP_PKEY *PEM_read_PUBKEY_ex(FILE *fp, EVP_PKEY **x,
279     pem_password_cb *cb, void *u,
280     OSSL_LIB_CTX *libctx, const char *propq)
281 {
282     BIO *b;
283     EVP_PKEY *ret;
284 
285     if ((b = BIO_new(BIO_s_file())) == NULL) {
286         ERR_raise(ERR_LIB_PEM, ERR_R_BUF_LIB);
287         return 0;
288     }
289     BIO_set_fp(b, fp, BIO_NOCLOSE);
290     ret = PEM_read_bio_PUBKEY_ex(b, x, cb, u, libctx, propq);
291     BIO_free(b);
292     return ret;
293 }
294 
PEM_read_PUBKEY(FILE * fp,EVP_PKEY ** x,pem_password_cb * cb,void * u)295 EVP_PKEY *PEM_read_PUBKEY(FILE *fp, EVP_PKEY **x, pem_password_cb *cb, void *u)
296 {
297     return PEM_read_PUBKEY_ex(fp, x, cb, u, NULL, NULL);
298 }
299 #endif
300 
PEM_read_bio_PrivateKey_ex(BIO * bp,EVP_PKEY ** x,pem_password_cb * cb,void * u,OSSL_LIB_CTX * libctx,const char * propq)301 EVP_PKEY *PEM_read_bio_PrivateKey_ex(BIO *bp, EVP_PKEY **x,
302     pem_password_cb *cb, void *u,
303     OSSL_LIB_CTX *libctx, const char *propq)
304 {
305     return pem_read_bio_key(bp, x, cb, u, libctx, propq,
306         /* we also want the public key, if available */
307         EVP_PKEY_KEYPAIR);
308 }
309 
PEM_read_bio_PrivateKey(BIO * bp,EVP_PKEY ** x,pem_password_cb * cb,void * u)310 EVP_PKEY *PEM_read_bio_PrivateKey(BIO *bp, EVP_PKEY **x, pem_password_cb *cb,
311     void *u)
312 {
313     return PEM_read_bio_PrivateKey_ex(bp, x, cb, u, NULL, NULL);
314 }
315 
PEM_write_cb_ex_fnsig(PrivateKey,EVP_PKEY,BIO,write_bio)316 PEM_write_cb_ex_fnsig(PrivateKey, EVP_PKEY, BIO, write_bio)
317 {
318     IMPLEMENT_PEM_provided_write_body_vars(pkey, PrivateKey, propq);
319 
320     IMPLEMENT_PEM_provided_write_body_pass();
321     IMPLEMENT_PEM_provided_write_body_main(pkey, bio);
322 
323 legacy:
324     if (x != NULL && (x->ameth == NULL || x->ameth->priv_encode != NULL))
325         return PEM_write_bio_PKCS8PrivateKey(out, x, enc,
326             (const char *)kstr, klen, cb, u);
327     return PEM_write_bio_PrivateKey_traditional(out, x, enc, kstr, klen, cb, u);
328 }
329 
PEM_write_cb_fnsig(PrivateKey,EVP_PKEY,BIO,write_bio)330 PEM_write_cb_fnsig(PrivateKey, EVP_PKEY, BIO, write_bio)
331 {
332     return PEM_write_bio_PrivateKey_ex(out, x, enc, kstr, klen, cb, u,
333         NULL, NULL);
334 }
335 
336 /*
337  * Note: there is no way to tell a provided pkey encoder to use "traditional"
338  * encoding.  Therefore, if the pkey is provided, we try to take a copy
339  */
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)340 int PEM_write_bio_PrivateKey_traditional(BIO *bp, const EVP_PKEY *x,
341     const EVP_CIPHER *enc,
342     const unsigned char *kstr, int klen,
343     pem_password_cb *cb, void *u)
344 {
345     char pem_str[80];
346     EVP_PKEY *copy = NULL;
347     int ret;
348 
349     if (x == NULL)
350         return 0;
351 
352     if (evp_pkey_is_assigned(x)
353         && evp_pkey_is_provided(x)
354         && evp_pkey_copy_downgraded(&copy, x))
355         x = copy;
356 
357     if (x->ameth == NULL || x->ameth->old_priv_encode == NULL) {
358         ERR_raise(ERR_LIB_PEM, PEM_R_UNSUPPORTED_PUBLIC_KEY_TYPE);
359         EVP_PKEY_free(copy);
360         return 0;
361     }
362     BIO_snprintf(pem_str, 80, "%s PRIVATE KEY", x->ameth->pem_str);
363     ret = PEM_ASN1_write_bio((i2d_of_void *)i2d_PrivateKey,
364         pem_str, bp, x, enc, kstr, klen, cb, u);
365 
366     EVP_PKEY_free(copy);
367     return ret;
368 }
369 
no_password_cb(char * buf,int num,int rwflag,void * userdata)370 static int no_password_cb(char *buf, int num, int rwflag, void *userdata)
371 {
372     return -1;
373 }
374 
PEM_read_bio_Parameters_ex(BIO * bp,EVP_PKEY ** x,OSSL_LIB_CTX * libctx,const char * propq)375 EVP_PKEY *PEM_read_bio_Parameters_ex(BIO *bp, EVP_PKEY **x,
376     OSSL_LIB_CTX *libctx, const char *propq)
377 {
378     /*
379      * PEM_read_bio_Parameters(_ex) should never ask for a password. Any attempt
380      * to get a password just fails.
381      */
382     return pem_read_bio_key(bp, x, no_password_cb, NULL, libctx, propq,
383         EVP_PKEY_KEY_PARAMETERS);
384 }
385 
PEM_read_bio_Parameters(BIO * bp,EVP_PKEY ** x)386 EVP_PKEY *PEM_read_bio_Parameters(BIO *bp, EVP_PKEY **x)
387 {
388     return PEM_read_bio_Parameters_ex(bp, x, NULL, NULL);
389 }
390 
PEM_write_fnsig(Parameters,EVP_PKEY,BIO,write_bio)391 PEM_write_fnsig(Parameters, EVP_PKEY, BIO, write_bio)
392 {
393     char pem_str[80];
394     IMPLEMENT_PEM_provided_write_body_vars(pkey, Parameters, NULL);
395 
396     IMPLEMENT_PEM_provided_write_body_main(pkey, bio);
397 
398 legacy:
399     if (!x->ameth || !x->ameth->param_encode)
400         return 0;
401 
402     BIO_snprintf(pem_str, 80, "%s PARAMETERS", x->ameth->pem_str);
403     return PEM_ASN1_write_bio((i2d_of_void *)x->ameth->param_encode,
404         pem_str, out, x, NULL, NULL, 0, 0, NULL);
405 }
406 
407 #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)408 EVP_PKEY *PEM_read_PrivateKey_ex(FILE *fp, EVP_PKEY **x, pem_password_cb *cb,
409     void *u, OSSL_LIB_CTX *libctx,
410     const char *propq)
411 {
412     BIO *b;
413     EVP_PKEY *ret;
414 
415     if ((b = BIO_new(BIO_s_file())) == NULL) {
416         ERR_raise(ERR_LIB_PEM, ERR_R_BUF_LIB);
417         return 0;
418     }
419     BIO_set_fp(b, fp, BIO_NOCLOSE);
420     ret = PEM_read_bio_PrivateKey_ex(b, x, cb, u, libctx, propq);
421     BIO_free(b);
422     return ret;
423 }
424 
PEM_read_PrivateKey(FILE * fp,EVP_PKEY ** x,pem_password_cb * cb,void * u)425 EVP_PKEY *PEM_read_PrivateKey(FILE *fp, EVP_PKEY **x, pem_password_cb *cb,
426     void *u)
427 {
428     return PEM_read_PrivateKey_ex(fp, x, cb, u, NULL, NULL);
429 }
430 
PEM_write_cb_ex_fnsig(PrivateKey,EVP_PKEY,FILE,write)431 PEM_write_cb_ex_fnsig(PrivateKey, EVP_PKEY, FILE, write)
432 {
433     BIO *b;
434     int ret;
435 
436     if ((b = BIO_new_fp(out, BIO_NOCLOSE)) == NULL) {
437         ERR_raise(ERR_LIB_PEM, ERR_R_BUF_LIB);
438         return 0;
439     }
440     ret = PEM_write_bio_PrivateKey_ex(b, x, enc, kstr, klen, cb, u,
441         libctx, propq);
442     BIO_free(b);
443     return ret;
444 }
445 
PEM_write_cb_fnsig(PrivateKey,EVP_PKEY,FILE,write)446 PEM_write_cb_fnsig(PrivateKey, EVP_PKEY, FILE, write)
447 {
448     return PEM_write_PrivateKey_ex(out, x, enc, kstr, klen, cb, u, NULL, NULL);
449 }
450 #endif
451