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1 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
2  * All rights reserved.
3  *
4  * This package is an SSL implementation written
5  * by Eric Young (eay@cryptsoft.com).
6  * The implementation was written so as to conform with Netscapes SSL.
7  *
8  * This library is free for commercial and non-commercial use as long as
9  * the following conditions are aheared to.  The following conditions
10  * apply to all code found in this distribution, be it the RC4, RSA,
11  * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
12  * included with this distribution is covered by the same copyright terms
13  * except that the holder is Tim Hudson (tjh@cryptsoft.com).
14  *
15  * Copyright remains Eric Young's, and as such any Copyright notices in
16  * the code are not to be removed.
17  * If this package is used in a product, Eric Young should be given attribution
18  * as the author of the parts of the library used.
19  * This can be in the form of a textual message at program startup or
20  * in documentation (online or textual) provided with the package.
21  *
22  * Redistribution and use in source and binary forms, with or without
23  * modification, are permitted provided that the following conditions
24  * are met:
25  * 1. Redistributions of source code must retain the copyright
26  *    notice, this list of conditions and the following disclaimer.
27  * 2. Redistributions in binary form must reproduce the above copyright
28  *    notice, this list of conditions and the following disclaimer in the
29  *    documentation and/or other materials provided with the distribution.
30  * 3. All advertising materials mentioning features or use of this software
31  *    must display the following acknowledgement:
32  *    "This product includes cryptographic software written by
33  *     Eric Young (eay@cryptsoft.com)"
34  *    The word 'cryptographic' can be left out if the rouines from the library
35  *    being used are not cryptographic related :-).
36  * 4. If you include any Windows specific code (or a derivative thereof) from
37  *    the apps directory (application code) you must include an acknowledgement:
38  *    "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
39  *
40  * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
41  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
42  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
43  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
44  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
45  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
46  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
47  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
48  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
49  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
50  * SUCH DAMAGE.
51  *
52  * The licence and distribution terms for any publically available version or
53  * derivative of this code cannot be changed.  i.e. this code cannot simply be
54  * copied and put under another distribution licence
55  * [including the GNU Public Licence.] */
56 
57 #ifndef OPENSSL_HEADER_RSA_H
58 #define OPENSSL_HEADER_RSA_H
59 
60 #include <openssl/base.h>
61 
62 #include <openssl/engine.h>
63 #include <openssl/ex_data.h>
64 #include <openssl/thread.h>
65 
66 #if defined(__cplusplus)
67 extern "C" {
68 #endif
69 
70 
71 // rsa.h contains functions for handling encryption and signature using RSA.
72 
73 
74 // Allocation and destruction.
75 //
76 // An |RSA| object represents a public or private RSA key. A given object may be
77 // used concurrently on multiple threads by non-mutating functions, provided no
78 // other thread is concurrently calling a mutating function. Unless otherwise
79 // documented, functions which take a |const| pointer are non-mutating and
80 // functions which take a non-|const| pointer are mutating.
81 
82 // RSA_new_public_key returns a new |RSA| object containing a public key with
83 // the specified parameters, or NULL on error or invalid input.
84 OPENSSL_EXPORT RSA *RSA_new_public_key(const BIGNUM *n, const BIGNUM *e);
85 
86 // RSA_new_private_key returns a new |RSA| object containing a private key with
87 // the specified parameters, or NULL on error or invalid input. All parameters
88 // are mandatory and may not be NULL.
89 //
90 // This function creates standard RSA private keys with CRT parameters.
91 OPENSSL_EXPORT RSA *RSA_new_private_key(const BIGNUM *n, const BIGNUM *e,
92                                         const BIGNUM *d, const BIGNUM *p,
93                                         const BIGNUM *q, const BIGNUM *dmp1,
94                                         const BIGNUM *dmq1, const BIGNUM *iqmp);
95 
96 // RSA_new returns a new, empty |RSA| object or NULL on error. Prefer using
97 // |RSA_new_public_key| or |RSA_new_private_key| to import an RSA key.
98 OPENSSL_EXPORT RSA *RSA_new(void);
99 
100 // RSA_new_method acts the same as |RSA_new| but takes an explicit |ENGINE|.
101 OPENSSL_EXPORT RSA *RSA_new_method(const ENGINE *engine);
102 
103 // RSA_free decrements the reference count of |rsa| and frees it if the
104 // reference count drops to zero.
105 OPENSSL_EXPORT void RSA_free(RSA *rsa);
106 
107 // RSA_up_ref increments the reference count of |rsa| and returns one. It does
108 // not mutate |rsa| for thread-safety purposes and may be used concurrently.
109 OPENSSL_EXPORT int RSA_up_ref(RSA *rsa);
110 
111 
112 // Properties.
113 
114 // RSA_bits returns the size of |rsa|, in bits.
115 OPENSSL_EXPORT unsigned RSA_bits(const RSA *rsa);
116 
117 // RSA_get0_n returns |rsa|'s public modulus.
118 OPENSSL_EXPORT const BIGNUM *RSA_get0_n(const RSA *rsa);
119 
120 // RSA_get0_e returns |rsa|'s public exponent.
121 OPENSSL_EXPORT const BIGNUM *RSA_get0_e(const RSA *rsa);
122 
123 // RSA_get0_d returns |rsa|'s private exponent. If |rsa| is a public key, this
124 // value will be NULL.
125 OPENSSL_EXPORT const BIGNUM *RSA_get0_d(const RSA *rsa);
126 
127 // RSA_get0_p returns |rsa|'s first private prime factor. If |rsa| is a public
128 // key or lacks its prime factors, this value will be NULL.
129 OPENSSL_EXPORT const BIGNUM *RSA_get0_p(const RSA *rsa);
130 
131 // RSA_get0_q returns |rsa|'s second private prime factor. If |rsa| is a public
132 // key or lacks its prime factors, this value will be NULL.
133 OPENSSL_EXPORT const BIGNUM *RSA_get0_q(const RSA *rsa);
134 
135 // RSA_get0_dmp1 returns d (mod p-1) for |rsa|. If |rsa| is a public key or
136 // lacks CRT parameters, this value will be NULL.
137 OPENSSL_EXPORT const BIGNUM *RSA_get0_dmp1(const RSA *rsa);
138 
139 // RSA_get0_dmq1 returns d (mod q-1) for |rsa|. If |rsa| is a public key or
140 // lacks CRT parameters, this value will be NULL.
141 OPENSSL_EXPORT const BIGNUM *RSA_get0_dmq1(const RSA *rsa);
142 
143 // RSA_get0_iqmp returns q^-1 (mod p). If |rsa| is a public key or lacks CRT
144 // parameters, this value will be NULL.
145 OPENSSL_EXPORT const BIGNUM *RSA_get0_iqmp(const RSA *rsa);
146 
147 // RSA_get0_key sets |*out_n|, |*out_e|, and |*out_d|, if non-NULL, to |rsa|'s
148 // modulus, public exponent, and private exponent, respectively. If |rsa| is a
149 // public key, the private exponent will be set to NULL.
150 OPENSSL_EXPORT void RSA_get0_key(const RSA *rsa, const BIGNUM **out_n,
151                                  const BIGNUM **out_e, const BIGNUM **out_d);
152 
153 // RSA_get0_factors sets |*out_p| and |*out_q|, if non-NULL, to |rsa|'s prime
154 // factors. If |rsa| is a public key, they will be set to NULL.
155 OPENSSL_EXPORT void RSA_get0_factors(const RSA *rsa, const BIGNUM **out_p,
156                                      const BIGNUM **out_q);
157 
158 // RSA_get0_crt_params sets |*out_dmp1|, |*out_dmq1|, and |*out_iqmp|, if
159 // non-NULL, to |rsa|'s CRT parameters. These are d (mod p-1), d (mod q-1) and
160 // q^-1 (mod p), respectively. If |rsa| is a public key, each parameter will be
161 // set to NULL.
162 OPENSSL_EXPORT void RSA_get0_crt_params(const RSA *rsa, const BIGNUM **out_dmp1,
163                                         const BIGNUM **out_dmq1,
164                                         const BIGNUM **out_iqmp);
165 
166 
167 // Setting individual properties.
168 //
169 // These functions allow setting individual properties of an |RSA| object. This
170 // is typically used with |RSA_new| to construct an RSA key field by field.
171 // Prefer instead to use |RSA_new_public_key| and |RSA_new_private_key|. These
172 // functions defer some initialization to the first use of an |RSA| object. This
173 // means invalid inputs may be caught late.
174 //
175 // TODO(crbug.com/boringssl/316): This deferred initialization also causes
176 // performance problems in multi-threaded applications. The preferred APIs
177 // currently have the same issues, but they will initialize eagerly in the
178 // future.
179 
180 // RSA_set0_key sets |rsa|'s modulus, public exponent, and private exponent to
181 // |n|, |e|, and |d| respectively, if non-NULL. On success, it takes ownership
182 // of each argument and returns one. Otherwise, it returns zero.
183 //
184 // |d| may be NULL, but |n| and |e| must either be non-NULL or already
185 // configured on |rsa|.
186 //
187 // It is an error to call this function after |rsa| has been used for a
188 // cryptographic operation. Construct a new |RSA| object instead.
189 OPENSSL_EXPORT int RSA_set0_key(RSA *rsa, BIGNUM *n, BIGNUM *e, BIGNUM *d);
190 
191 // RSA_set0_factors sets |rsa|'s prime factors to |p| and |q|, if non-NULL, and
192 // takes ownership of them. On success, it takes ownership of each argument and
193 // returns one. Otherwise, it returns zero.
194 //
195 // Each argument must either be non-NULL or already configured on |rsa|.
196 //
197 // It is an error to call this function after |rsa| has been used for a
198 // cryptographic operation. Construct a new |RSA| object instead.
199 OPENSSL_EXPORT int RSA_set0_factors(RSA *rsa, BIGNUM *p, BIGNUM *q);
200 
201 // RSA_set0_crt_params sets |rsa|'s CRT parameters to |dmp1|, |dmq1|, and
202 // |iqmp|, if non-NULL, and takes ownership of them. On success, it takes
203 // ownership of its parameters and returns one. Otherwise, it returns zero.
204 //
205 // Each argument must either be non-NULL or already configured on |rsa|.
206 //
207 // It is an error to call this function after |rsa| has been used for a
208 // cryptographic operation. Construct a new |RSA| object instead.
209 OPENSSL_EXPORT int RSA_set0_crt_params(RSA *rsa, BIGNUM *dmp1, BIGNUM *dmq1,
210                                        BIGNUM *iqmp);
211 
212 
213 // Key generation.
214 
215 // RSA_generate_key_ex generates a new RSA key where the modulus has size
216 // |bits| and the public exponent is |e|. If unsure, |RSA_F4| is a good value
217 // for |e|. If |cb| is not NULL then it is called during the key generation
218 // process. In addition to the calls documented for |BN_generate_prime_ex|, it
219 // is called with event=2 when the n'th prime is rejected as unsuitable and
220 // with event=3 when a suitable value for |p| is found.
221 //
222 // It returns one on success or zero on error.
223 OPENSSL_EXPORT int RSA_generate_key_ex(RSA *rsa, int bits, const BIGNUM *e,
224                                        BN_GENCB *cb);
225 
226 // RSA_generate_key_fips behaves like |RSA_generate_key_ex| but performs
227 // additional checks for FIPS compliance. The public exponent is always 65537
228 // and |bits| must be either 2048 or 3072.
229 OPENSSL_EXPORT int RSA_generate_key_fips(RSA *rsa, int bits, BN_GENCB *cb);
230 
231 
232 // Encryption / Decryption
233 //
234 // These functions are considered non-mutating for thread-safety purposes and
235 // may be used concurrently.
236 
237 // RSA_PKCS1_PADDING denotes PKCS#1 v1.5 padding. When used with encryption,
238 // this is RSAES-PKCS1-v1_5. When used with signing, this is RSASSA-PKCS1-v1_5.
239 #define RSA_PKCS1_PADDING 1
240 
241 // RSA_NO_PADDING denotes a raw RSA operation.
242 #define RSA_NO_PADDING 3
243 
244 // RSA_PKCS1_OAEP_PADDING denotes the RSAES-OAEP encryption scheme.
245 #define RSA_PKCS1_OAEP_PADDING 4
246 
247 // RSA_PKCS1_PSS_PADDING denotes the RSASSA-PSS signature scheme. This value may
248 // not be passed into |RSA_sign_raw|, only |EVP_PKEY_CTX_set_rsa_padding|. See
249 // also |RSA_sign_pss_mgf1| and |RSA_verify_pss_mgf1|.
250 #define RSA_PKCS1_PSS_PADDING 6
251 
252 // RSA_encrypt encrypts |in_len| bytes from |in| to the public key from |rsa|
253 // and writes, at most, |max_out| bytes of encrypted data to |out|. The
254 // |max_out| argument must be, at least, |RSA_size| in order to ensure success.
255 //
256 // It returns 1 on success or zero on error.
257 //
258 // The |padding| argument must be one of the |RSA_*_PADDING| values. If in
259 // doubt, use |RSA_PKCS1_OAEP_PADDING| for new protocols but
260 // |RSA_PKCS1_PADDING| is most common.
261 OPENSSL_EXPORT int RSA_encrypt(RSA *rsa, size_t *out_len, uint8_t *out,
262                                size_t max_out, const uint8_t *in, size_t in_len,
263                                int padding);
264 
265 // RSA_decrypt decrypts |in_len| bytes from |in| with the private key from
266 // |rsa| and writes, at most, |max_out| bytes of plaintext to |out|. The
267 // |max_out| argument must be, at least, |RSA_size| in order to ensure success.
268 //
269 // It returns 1 on success or zero on error.
270 //
271 // The |padding| argument must be one of the |RSA_*_PADDING| values. If in
272 // doubt, use |RSA_PKCS1_OAEP_PADDING| for new protocols.
273 //
274 // Passing |RSA_PKCS1_PADDING| into this function is deprecated and insecure. If
275 // implementing a protocol using RSAES-PKCS1-V1_5, use |RSA_NO_PADDING| and then
276 // check padding in constant-time combined with a swap to a random session key
277 // or other mitigation. See "Chosen Ciphertext Attacks Against Protocols Based
278 // on the RSA Encryption Standard PKCS #1", Daniel Bleichenbacher, Advances in
279 // Cryptology (Crypto '98).
280 OPENSSL_EXPORT int RSA_decrypt(RSA *rsa, size_t *out_len, uint8_t *out,
281                                size_t max_out, const uint8_t *in, size_t in_len,
282                                int padding);
283 
284 // RSA_public_encrypt encrypts |flen| bytes from |from| to the public key in
285 // |rsa| and writes the encrypted data to |to|. The |to| buffer must have at
286 // least |RSA_size| bytes of space. It returns the number of bytes written, or
287 // -1 on error. The |padding| argument must be one of the |RSA_*_PADDING|
288 // values. If in doubt, use |RSA_PKCS1_OAEP_PADDING| for new protocols but
289 // |RSA_PKCS1_PADDING| is most common.
290 //
291 // WARNING: this function is dangerous because it breaks the usual return value
292 // convention. Use |RSA_encrypt| instead.
293 OPENSSL_EXPORT int RSA_public_encrypt(size_t flen, const uint8_t *from,
294                                       uint8_t *to, RSA *rsa, int padding);
295 
296 // RSA_private_decrypt decrypts |flen| bytes from |from| with the public key in
297 // |rsa| and writes the plaintext to |to|. The |to| buffer must have at least
298 // |RSA_size| bytes of space. It returns the number of bytes written, or -1 on
299 // error. The |padding| argument must be one of the |RSA_*_PADDING| values. If
300 // in doubt, use |RSA_PKCS1_OAEP_PADDING| for new protocols. Passing
301 // |RSA_PKCS1_PADDING| into this function is deprecated and insecure. See
302 // |RSA_decrypt|.
303 //
304 // WARNING: this function is dangerous because it breaks the usual return value
305 // convention. Use |RSA_decrypt| instead.
306 OPENSSL_EXPORT int RSA_private_decrypt(size_t flen, const uint8_t *from,
307                                        uint8_t *to, RSA *rsa, int padding);
308 
309 
310 // Signing / Verification
311 //
312 // These functions are considered non-mutating for thread-safety purposes and
313 // may be used concurrently.
314 
315 // RSA_sign signs |digest_len| bytes of digest from |digest| with |rsa| using
316 // RSASSA-PKCS1-v1_5. It writes, at most, |RSA_size(rsa)| bytes to |out|. On
317 // successful return, the actual number of bytes written is written to
318 // |*out_len|.
319 //
320 // The |hash_nid| argument identifies the hash function used to calculate
321 // |digest| and is embedded in the resulting signature. For example, it might be
322 // |NID_sha256|.
323 //
324 // It returns 1 on success and zero on error.
325 //
326 // WARNING: |digest| must be the result of hashing the data to be signed with
327 // |hash_nid|. Passing unhashed inputs will not result in a secure signature
328 // scheme.
329 OPENSSL_EXPORT int RSA_sign(int hash_nid, const uint8_t *digest,
330                             size_t digest_len, uint8_t *out, unsigned *out_len,
331                             RSA *rsa);
332 
333 // RSA_sign_pss_mgf1 signs |digest_len| bytes from |digest| with the public key
334 // from |rsa| using RSASSA-PSS with MGF1 as the mask generation function. It
335 // writes, at most, |max_out| bytes of signature data to |out|. The |max_out|
336 // argument must be, at least, |RSA_size| in order to ensure success. It returns
337 // 1 on success or zero on error.
338 //
339 // The |md| and |mgf1_md| arguments identify the hash used to calculate |digest|
340 // and the MGF1 hash, respectively. If |mgf1_md| is NULL, |md| is
341 // used.
342 //
343 // |salt_len| specifies the expected salt length in bytes. If |salt_len| is -1,
344 // then the salt length is the same as the hash length. If -2, then the salt
345 // length is maximal given the size of |rsa|. If unsure, use -1.
346 //
347 // WARNING: |digest| must be the result of hashing the data to be signed with
348 // |md|. Passing unhashed inputs will not result in a secure signature scheme.
349 OPENSSL_EXPORT int RSA_sign_pss_mgf1(RSA *rsa, size_t *out_len, uint8_t *out,
350                                      size_t max_out, const uint8_t *digest,
351                                      size_t digest_len, const EVP_MD *md,
352                                      const EVP_MD *mgf1_md, int salt_len);
353 
354 // RSA_sign_raw performs the private key portion of computing a signature with
355 // |rsa|. It writes, at most, |max_out| bytes of signature data to |out|. The
356 // |max_out| argument must be, at least, |RSA_size| in order to ensure the
357 // output fits. It returns 1 on success or zero on error.
358 //
359 // If |padding| is |RSA_PKCS1_PADDING|, this function wraps |in| with the
360 // padding portion of RSASSA-PKCS1-v1_5 and then performs the raw private key
361 // operation. The caller is responsible for hashing the input and wrapping it in
362 // a DigestInfo structure.
363 //
364 // If |padding| is |RSA_NO_PADDING|, this function only performs the raw private
365 // key operation, interpreting |in| as a integer modulo n. The caller is
366 // responsible for hashing the input and encoding it for the signature scheme
367 // being implemented.
368 //
369 // WARNING: This function is a building block for a signature scheme, not a
370 // complete one. |in| must be the result of hashing and encoding the data as
371 // needed for the scheme being implemented. Passing in arbitrary inputs will not
372 // result in a secure signature scheme.
373 OPENSSL_EXPORT int RSA_sign_raw(RSA *rsa, size_t *out_len, uint8_t *out,
374                                 size_t max_out, const uint8_t *in,
375                                 size_t in_len, int padding);
376 
377 // RSA_verify verifies that |sig_len| bytes from |sig| are a valid,
378 // RSASSA-PKCS1-v1_5 signature of |digest_len| bytes at |digest| by |rsa|.
379 //
380 // The |hash_nid| argument identifies the hash function used to calculate
381 // |digest| and is embedded in the resulting signature in order to prevent hash
382 // confusion attacks. For example, it might be |NID_sha256|.
383 //
384 // It returns one if the signature is valid and zero otherwise.
385 //
386 // WARNING: this differs from the original, OpenSSL function which additionally
387 // returned -1 on error.
388 //
389 // WARNING: |digest| must be the result of hashing the data to be verified with
390 // |hash_nid|. Passing unhashed input will not result in a secure signature
391 // scheme.
392 OPENSSL_EXPORT int RSA_verify(int hash_nid, const uint8_t *digest,
393                               size_t digest_len, const uint8_t *sig,
394                               size_t sig_len, RSA *rsa);
395 
396 // RSA_verify_pss_mgf1 verifies that |sig_len| bytes from |sig| are a valid,
397 // RSASSA-PSS signature of |digest_len| bytes at |digest| by |rsa|. It returns
398 // one if the signature is valid and zero otherwise. MGF1 is used as the mask
399 // generation function.
400 //
401 // The |md| and |mgf1_md| arguments identify the hash used to calculate |digest|
402 // and the MGF1 hash, respectively. If |mgf1_md| is NULL, |md| is
403 // used. |salt_len| specifies the expected salt length in bytes.
404 //
405 // If |salt_len| is -1, then the salt length is the same as the hash length. If
406 // -2, then the salt length is recovered and all values accepted. If unsure, use
407 // -1.
408 //
409 // WARNING: |digest| must be the result of hashing the data to be verified with
410 // |md|. Passing unhashed input will not result in a secure signature scheme.
411 OPENSSL_EXPORT int RSA_verify_pss_mgf1(RSA *rsa, const uint8_t *digest,
412                                        size_t digest_len, const EVP_MD *md,
413                                        const EVP_MD *mgf1_md, int salt_len,
414                                        const uint8_t *sig, size_t sig_len);
415 
416 // RSA_verify_raw performs the public key portion of verifying |in_len| bytes of
417 // signature from |in| using the public key from |rsa|. On success, it returns
418 // one and writes, at most, |max_out| bytes of output to |out|. The |max_out|
419 // argument must be, at least, |RSA_size| in order to ensure the output fits. On
420 // failure or invalid input, it returns zero.
421 //
422 // If |padding| is |RSA_PKCS1_PADDING|, this function checks the padding portion
423 // of RSASSA-PKCS1-v1_5 and outputs the remainder of the encoded digest. The
424 // caller is responsible for checking the output is a DigestInfo-wrapped digest
425 // of the message.
426 //
427 // If |padding| is |RSA_NO_PADDING|, this function only performs the raw public
428 // key operation. The caller is responsible for checking the output is a valid
429 // result for the signature scheme being implemented.
430 //
431 // WARNING: This function is a building block for a signature scheme, not a
432 // complete one. Checking for arbitrary strings in |out| will not result in a
433 // secure signature scheme.
434 OPENSSL_EXPORT int RSA_verify_raw(RSA *rsa, size_t *out_len, uint8_t *out,
435                                   size_t max_out, const uint8_t *in,
436                                   size_t in_len, int padding);
437 
438 // RSA_private_encrypt performs the private key portion of computing a signature
439 // with |rsa|. It takes |flen| bytes from |from| as input and writes the result
440 // to |to|. The |to| buffer must have at least |RSA_size| bytes of space. It
441 // returns the number of bytes written, or -1 on error.
442 //
443 // For the interpretation of |padding| and the input, see |RSA_sign_raw|.
444 //
445 // WARNING: This function is a building block for a signature scheme, not a
446 // complete one. See |RSA_sign_raw| for details.
447 //
448 // WARNING: This function is dangerous because it breaks the usual return value
449 // convention. Use |RSA_sign_raw| instead.
450 OPENSSL_EXPORT int RSA_private_encrypt(size_t flen, const uint8_t *from,
451                                        uint8_t *to, RSA *rsa, int padding);
452 
453 // RSA_public_decrypt performs the public key portion of verifying |flen| bytes
454 // of signature from |from| using the public key from |rsa|. It writes the
455 // result to |to|, which must have at least |RSA_size| bytes of space. It
456 // returns the number of bytes written, or -1 on error.
457 //
458 // For the interpretation of |padding| and the result, see |RSA_verify_raw|.
459 //
460 // WARNING: This function is a building block for a signature scheme, not a
461 // complete one. See |RSA_verify_raw| for details.
462 //
463 // WARNING: This function is dangerous because it breaks the usual return value
464 // convention. Use |RSA_verify_raw| instead.
465 OPENSSL_EXPORT int RSA_public_decrypt(size_t flen, const uint8_t *from,
466                                       uint8_t *to, RSA *rsa, int padding);
467 
468 
469 // Utility functions.
470 
471 // RSA_size returns the number of bytes in the modulus, which is also the size
472 // of a signature or encrypted value using |rsa|.
473 OPENSSL_EXPORT unsigned RSA_size(const RSA *rsa);
474 
475 // RSA_is_opaque returns one if |rsa| is opaque and doesn't expose its key
476 // material. Otherwise it returns zero.
477 OPENSSL_EXPORT int RSA_is_opaque(const RSA *rsa);
478 
479 // RSAPublicKey_dup allocates a fresh |RSA| and copies the public key from
480 // |rsa| into it. It returns the fresh |RSA| object, or NULL on error.
481 OPENSSL_EXPORT RSA *RSAPublicKey_dup(const RSA *rsa);
482 
483 // RSAPrivateKey_dup allocates a fresh |RSA| and copies the private key from
484 // |rsa| into it. It returns the fresh |RSA| object, or NULL on error.
485 OPENSSL_EXPORT RSA *RSAPrivateKey_dup(const RSA *rsa);
486 
487 // RSA_check_key performs basic validity tests on |rsa|. It returns one if
488 // they pass and zero otherwise. Opaque keys and public keys always pass. If it
489 // returns zero then a more detailed error is available on the error queue.
490 OPENSSL_EXPORT int RSA_check_key(const RSA *rsa);
491 
492 // RSA_check_fips performs public key validity tests on |key|. It returns one if
493 // they pass and zero otherwise. Opaque keys always fail. This function does not
494 // mutate |rsa| for thread-safety purposes and may be used concurrently.
495 OPENSSL_EXPORT int RSA_check_fips(RSA *key);
496 
497 // RSA_verify_PKCS1_PSS_mgf1 verifies that |EM| is a correct PSS padding of
498 // |mHash|, where |mHash| is a digest produced by |Hash|. |EM| must point to
499 // exactly |RSA_size(rsa)| bytes of data. The |mgf1Hash| argument specifies the
500 // hash function for generating the mask. If NULL, |Hash| is used. The |sLen|
501 // argument specifies the expected salt length in bytes. If |sLen| is -1 then
502 // the salt length is the same as the hash length. If -2, then the salt length
503 // is recovered and all values accepted.
504 //
505 // If unsure, use -1.
506 //
507 // It returns one on success or zero on error.
508 //
509 // This function implements only the low-level padding logic. Use
510 // |RSA_verify_pss_mgf1| instead.
511 OPENSSL_EXPORT int RSA_verify_PKCS1_PSS_mgf1(const RSA *rsa,
512                                              const uint8_t *mHash,
513                                              const EVP_MD *Hash,
514                                              const EVP_MD *mgf1Hash,
515                                              const uint8_t *EM, int sLen);
516 
517 // RSA_padding_add_PKCS1_PSS_mgf1 writes a PSS padding of |mHash| to |EM|,
518 // where |mHash| is a digest produced by |Hash|. |RSA_size(rsa)| bytes of
519 // output will be written to |EM|. The |mgf1Hash| argument specifies the hash
520 // function for generating the mask. If NULL, |Hash| is used. The |sLen|
521 // argument specifies the expected salt length in bytes. If |sLen| is -1 then
522 // the salt length is the same as the hash length. If -2, then the salt length
523 // is maximal given the space in |EM|.
524 //
525 // It returns one on success or zero on error.
526 //
527 // This function implements only the low-level padding logic. Use
528 // |RSA_sign_pss_mgf1| instead.
529 OPENSSL_EXPORT int RSA_padding_add_PKCS1_PSS_mgf1(const RSA *rsa, uint8_t *EM,
530                                                   const uint8_t *mHash,
531                                                   const EVP_MD *Hash,
532                                                   const EVP_MD *mgf1Hash,
533                                                   int sLen);
534 
535 // RSA_padding_add_PKCS1_OAEP_mgf1 writes an OAEP padding of |from| to |to|
536 // with the given parameters and hash functions. If |md| is NULL then SHA-1 is
537 // used. If |mgf1md| is NULL then the value of |md| is used (which means SHA-1
538 // if that, in turn, is NULL).
539 //
540 // It returns one on success or zero on error.
541 OPENSSL_EXPORT int RSA_padding_add_PKCS1_OAEP_mgf1(
542     uint8_t *to, size_t to_len, const uint8_t *from, size_t from_len,
543     const uint8_t *param, size_t param_len, const EVP_MD *md,
544     const EVP_MD *mgf1md);
545 
546 // RSA_add_pkcs1_prefix builds a version of |digest| prefixed with the
547 // DigestInfo header for the given hash function and sets |out_msg| to point to
548 // it. On successful return, if |*is_alloced| is one, the caller must release
549 // |*out_msg| with |OPENSSL_free|.
550 OPENSSL_EXPORT int RSA_add_pkcs1_prefix(uint8_t **out_msg, size_t *out_msg_len,
551                                         int *is_alloced, int hash_nid,
552                                         const uint8_t *digest,
553                                         size_t digest_len);
554 
555 
556 // ASN.1 functions.
557 
558 // RSA_parse_public_key parses a DER-encoded RSAPublicKey structure (RFC 8017)
559 // from |cbs| and advances |cbs|. It returns a newly-allocated |RSA| or NULL on
560 // error.
561 OPENSSL_EXPORT RSA *RSA_parse_public_key(CBS *cbs);
562 
563 // RSA_public_key_from_bytes parses |in| as a DER-encoded RSAPublicKey structure
564 // (RFC 8017). It returns a newly-allocated |RSA| or NULL on error.
565 OPENSSL_EXPORT RSA *RSA_public_key_from_bytes(const uint8_t *in, size_t in_len);
566 
567 // RSA_marshal_public_key marshals |rsa| as a DER-encoded RSAPublicKey structure
568 // (RFC 8017) and appends the result to |cbb|. It returns one on success and
569 // zero on failure.
570 OPENSSL_EXPORT int RSA_marshal_public_key(CBB *cbb, const RSA *rsa);
571 
572 // RSA_public_key_to_bytes marshals |rsa| as a DER-encoded RSAPublicKey
573 // structure (RFC 8017) and, on success, sets |*out_bytes| to a newly allocated
574 // buffer containing the result and returns one. Otherwise, it returns zero. The
575 // result should be freed with |OPENSSL_free|.
576 OPENSSL_EXPORT int RSA_public_key_to_bytes(uint8_t **out_bytes, size_t *out_len,
577                                            const RSA *rsa);
578 
579 // RSA_parse_private_key parses a DER-encoded RSAPrivateKey structure (RFC 8017)
580 // from |cbs| and advances |cbs|. It returns a newly-allocated |RSA| or NULL on
581 // error.
582 OPENSSL_EXPORT RSA *RSA_parse_private_key(CBS *cbs);
583 
584 // RSA_private_key_from_bytes parses |in| as a DER-encoded RSAPrivateKey
585 // structure (RFC 8017). It returns a newly-allocated |RSA| or NULL on error.
586 OPENSSL_EXPORT RSA *RSA_private_key_from_bytes(const uint8_t *in,
587                                                size_t in_len);
588 
589 // RSA_marshal_private_key marshals |rsa| as a DER-encoded RSAPrivateKey
590 // structure (RFC 8017) and appends the result to |cbb|. It returns one on
591 // success and zero on failure.
592 OPENSSL_EXPORT int RSA_marshal_private_key(CBB *cbb, const RSA *rsa);
593 
594 // RSA_private_key_to_bytes marshals |rsa| as a DER-encoded RSAPrivateKey
595 // structure (RFC 8017) and, on success, sets |*out_bytes| to a newly allocated
596 // buffer containing the result and returns one. Otherwise, it returns zero. The
597 // result should be freed with |OPENSSL_free|.
598 OPENSSL_EXPORT int RSA_private_key_to_bytes(uint8_t **out_bytes,
599                                             size_t *out_len, const RSA *rsa);
600 
601 
602 // Obscure RSA variants.
603 //
604 // These functions allow creating RSA keys with obscure combinations of
605 // parameters.
606 
607 // RSA_new_private_key_no_crt behaves like |RSA_new_private_key| but constructs
608 // an RSA key without CRT coefficients.
609 //
610 // Keys created by this function will be less performant and cannot be
611 // serialized.
612 OPENSSL_EXPORT RSA *RSA_new_private_key_no_crt(const BIGNUM *n, const BIGNUM *e,
613                                                const BIGNUM *d);
614 
615 // RSA_new_private_key_no_e behaves like |RSA_new_private_key| but constructs an
616 // RSA key without CRT parameters or public exponent.
617 //
618 // Keys created by this function will be less performant, cannot be serialized,
619 // and lack hardening measures that protect against side channels and fault
620 // attacks.
621 OPENSSL_EXPORT RSA *RSA_new_private_key_no_e(const BIGNUM *n, const BIGNUM *d);
622 
623 // RSA_new_public_key_large_e behaves like |RSA_new_public_key| but allows any
624 // |e| up to |n|.
625 //
626 // BoringSSL typically bounds public exponents as a denial-of-service
627 // mitigation. Keys created by this function may perform worse than those
628 // created by |RSA_new_public_key|.
629 OPENSSL_EXPORT RSA *RSA_new_public_key_large_e(const BIGNUM *n,
630                                                const BIGNUM *e);
631 
632 // RSA_new_private_key_large_e behaves like |RSA_new_private_key| but allows any
633 // |e| up to |n|.
634 //
635 // BoringSSL typically bounds public exponents as a denial-of-service
636 // mitigation. Keys created by this function may perform worse than those
637 // created by |RSA_new_private_key|.
638 OPENSSL_EXPORT RSA *RSA_new_private_key_large_e(
639     const BIGNUM *n, const BIGNUM *e, const BIGNUM *d, const BIGNUM *p,
640     const BIGNUM *q, const BIGNUM *dmp1, const BIGNUM *dmq1,
641     const BIGNUM *iqmp);
642 
643 
644 // ex_data functions.
645 //
646 // See |ex_data.h| for details.
647 
648 OPENSSL_EXPORT int RSA_get_ex_new_index(long argl, void *argp,
649                                         CRYPTO_EX_unused *unused,
650                                         CRYPTO_EX_dup *dup_unused,
651                                         CRYPTO_EX_free *free_func);
652 OPENSSL_EXPORT int RSA_set_ex_data(RSA *rsa, int idx, void *arg);
653 OPENSSL_EXPORT void *RSA_get_ex_data(const RSA *rsa, int idx);
654 
655 
656 // Flags.
657 
658 // RSA_FLAG_OPAQUE specifies that this RSA_METHOD does not expose its key
659 // material. This may be set if, for instance, it is wrapping some other crypto
660 // API, like a platform key store.
661 #define RSA_FLAG_OPAQUE 1
662 
663 // RSA_FLAG_NO_BLINDING disables blinding of private operations, which is a
664 // dangerous thing to do. It is deprecated and should not be used. It will
665 // be ignored whenever possible.
666 //
667 // This flag must be used if a key without the public exponent |e| is used for
668 // private key operations; avoid using such keys whenever possible.
669 #define RSA_FLAG_NO_BLINDING 8
670 
671 // RSA_FLAG_EXT_PKEY is deprecated and ignored.
672 #define RSA_FLAG_EXT_PKEY 0x20
673 
674 // RSA_FLAG_NO_PUBLIC_EXPONENT indicates that private keys without a public
675 // exponent are allowed. This is an internal constant. Use
676 // |RSA_new_private_key_no_e| to construct such keys.
677 #define RSA_FLAG_NO_PUBLIC_EXPONENT 0x40
678 
679 // RSA_FLAG_LARGE_PUBLIC_EXPONENT indicates that keys with a large public
680 // exponent are allowed. This is an internal constant. Use
681 // |RSA_new_public_key_large_e| and |RSA_new_private_key_large_e| to construct
682 // such keys.
683 #define RSA_FLAG_LARGE_PUBLIC_EXPONENT 0x80
684 
685 
686 // RSA public exponent values.
687 
688 #define RSA_3 0x3
689 #define RSA_F4 0x10001
690 
691 
692 // Deprecated functions.
693 
694 #define RSA_METHOD_FLAG_NO_CHECK RSA_FLAG_OPAQUE
695 
696 // RSA_flags returns the flags for |rsa|. These are a bitwise OR of |RSA_FLAG_*|
697 // constants.
698 OPENSSL_EXPORT int RSA_flags(const RSA *rsa);
699 
700 // RSA_test_flags returns the subset of flags in |flags| which are set in |rsa|.
701 OPENSSL_EXPORT int RSA_test_flags(const RSA *rsa, int flags);
702 
703 // RSA_blinding_on returns one.
704 OPENSSL_EXPORT int RSA_blinding_on(RSA *rsa, BN_CTX *ctx);
705 
706 // RSA_generate_key behaves like |RSA_generate_key_ex|, which is what you
707 // should use instead. It returns NULL on error, or a newly-allocated |RSA| on
708 // success. This function is provided for compatibility only. The |callback|
709 // and |cb_arg| parameters must be NULL.
710 OPENSSL_EXPORT RSA *RSA_generate_key(int bits, uint64_t e, void *callback,
711                                      void *cb_arg);
712 
713 // d2i_RSAPublicKey parses a DER-encoded RSAPublicKey structure (RFC 8017) from
714 // |len| bytes at |*inp|, as described in |d2i_SAMPLE|.
715 //
716 // Use |RSA_parse_public_key| instead.
717 OPENSSL_EXPORT RSA *d2i_RSAPublicKey(RSA **out, const uint8_t **inp, long len);
718 
719 // i2d_RSAPublicKey marshals |in| to a DER-encoded RSAPublicKey structure (RFC
720 // 8017), as described in |i2d_SAMPLE|.
721 //
722 // Use |RSA_marshal_public_key| instead.
723 OPENSSL_EXPORT int i2d_RSAPublicKey(const RSA *in, uint8_t **outp);
724 
725 // d2i_RSAPrivateKey parses a DER-encoded RSAPrivateKey structure (RFC 8017)
726 // from |len| bytes at |*inp|, as described in |d2i_SAMPLE|.
727 //
728 // Use |RSA_parse_private_key| instead.
729 OPENSSL_EXPORT RSA *d2i_RSAPrivateKey(RSA **out, const uint8_t **inp, long len);
730 
731 // i2d_RSAPrivateKey marshals |in| to a DER-encoded RSAPrivateKey structure (RFC
732 // 8017), as described in |i2d_SAMPLE|.
733 //
734 // Use |RSA_marshal_private_key| instead.
735 OPENSSL_EXPORT int i2d_RSAPrivateKey(const RSA *in, uint8_t **outp);
736 
737 // RSA_padding_add_PKCS1_PSS acts like |RSA_padding_add_PKCS1_PSS_mgf1| but the
738 // |mgf1Hash| parameter of the latter is implicitly set to |Hash|.
739 //
740 // This function implements only the low-level padding logic. Use
741 // |RSA_sign_pss_mgf1| instead.
742 OPENSSL_EXPORT int RSA_padding_add_PKCS1_PSS(const RSA *rsa, uint8_t *EM,
743                                              const uint8_t *mHash,
744                                              const EVP_MD *Hash, int sLen);
745 
746 // RSA_verify_PKCS1_PSS acts like |RSA_verify_PKCS1_PSS_mgf1| but the
747 // |mgf1Hash| parameter of the latter is implicitly set to |Hash|.
748 //
749 // This function implements only the low-level padding logic. Use
750 // |RSA_verify_pss_mgf1| instead.
751 OPENSSL_EXPORT int RSA_verify_PKCS1_PSS(const RSA *rsa, const uint8_t *mHash,
752                                         const EVP_MD *Hash, const uint8_t *EM,
753                                         int sLen);
754 
755 // RSA_padding_add_PKCS1_OAEP acts like |RSA_padding_add_PKCS1_OAEP_mgf1| but
756 // the |md| and |mgf1md| parameters of the latter are implicitly set to NULL,
757 // which means SHA-1.
758 OPENSSL_EXPORT int RSA_padding_add_PKCS1_OAEP(uint8_t *to, size_t to_len,
759                                               const uint8_t *from,
760                                               size_t from_len,
761                                               const uint8_t *param,
762                                               size_t param_len);
763 
764 // RSA_print prints a textual representation of |rsa| to |bio|. It returns one
765 // on success or zero otherwise.
766 OPENSSL_EXPORT int RSA_print(BIO *bio, const RSA *rsa, int indent);
767 
768 // RSA_get0_pss_params returns NULL. In OpenSSL, this function retries RSA-PSS
769 // parameters associated with |RSA| objects, but BoringSSL does not support
770 // the id-RSASSA-PSS key encoding.
771 OPENSSL_EXPORT const RSA_PSS_PARAMS *RSA_get0_pss_params(const RSA *rsa);
772 
773 // RSA_new_method_no_e returns a newly-allocated |RSA| object backed by
774 // |engine|, with a public modulus of |n| and no known public exponent.
775 //
776 // Do not use this function. It exists only to support Conscrypt, whose use
777 // should be replaced with a more sound mechanism. See
778 // https://crbug.com/boringssl/602.
779 OPENSSL_EXPORT RSA *RSA_new_method_no_e(const ENGINE *engine, const BIGNUM *n);
780 
781 
782 struct rsa_meth_st {
783   struct openssl_method_common_st common;
784 
785   void *app_data;
786 
787   int (*init)(RSA *rsa);
788   int (*finish)(RSA *rsa);
789 
790   // size returns the size of the RSA modulus in bytes.
791   size_t (*size)(const RSA *rsa);
792 
793   int (*sign)(int type, const uint8_t *m, unsigned int m_length,
794               uint8_t *sigret, unsigned int *siglen, const RSA *rsa);
795 
796   // These functions mirror the |RSA_*| functions of the same name.
797   int (*sign_raw)(RSA *rsa, size_t *out_len, uint8_t *out, size_t max_out,
798                   const uint8_t *in, size_t in_len, int padding);
799   int (*decrypt)(RSA *rsa, size_t *out_len, uint8_t *out, size_t max_out,
800                  const uint8_t *in, size_t in_len, int padding);
801 
802   // private_transform takes a big-endian integer from |in|, calculates the
803   // d'th power of it, modulo the RSA modulus and writes the result as a
804   // big-endian integer to |out|. Both |in| and |out| are |len| bytes long and
805   // |len| is always equal to |RSA_size(rsa)|. If the result of the transform
806   // can be represented in fewer than |len| bytes, then |out| must be zero
807   // padded on the left.
808   //
809   // It returns one on success and zero otherwise.
810   //
811   // RSA decrypt and sign operations will call this, thus an ENGINE might wish
812   // to override it in order to avoid having to implement the padding
813   // functionality demanded by those, higher level, operations.
814   int (*private_transform)(RSA *rsa, uint8_t *out, const uint8_t *in,
815                            size_t len);
816 
817   int flags;
818 };
819 
820 
821 #if defined(__cplusplus)
822 }  // extern C
823 
824 extern "C++" {
825 
826 BSSL_NAMESPACE_BEGIN
827 
828 BORINGSSL_MAKE_DELETER(RSA, RSA_free)
829 BORINGSSL_MAKE_UP_REF(RSA, RSA_up_ref)
830 
831 BSSL_NAMESPACE_END
832 
833 }  // extern C++
834 
835 #endif
836 
837 #define RSA_R_BAD_ENCODING 100
838 #define RSA_R_BAD_E_VALUE 101
839 #define RSA_R_BAD_FIXED_HEADER_DECRYPT 102
840 #define RSA_R_BAD_PAD_BYTE_COUNT 103
841 #define RSA_R_BAD_RSA_PARAMETERS 104
842 #define RSA_R_BAD_SIGNATURE 105
843 #define RSA_R_BAD_VERSION 106
844 #define RSA_R_BLOCK_TYPE_IS_NOT_01 107
845 #define RSA_R_BN_NOT_INITIALIZED 108
846 #define RSA_R_CANNOT_RECOVER_MULTI_PRIME_KEY 109
847 #define RSA_R_CRT_PARAMS_ALREADY_GIVEN 110
848 #define RSA_R_CRT_VALUES_INCORRECT 111
849 #define RSA_R_DATA_LEN_NOT_EQUAL_TO_MOD_LEN 112
850 #define RSA_R_DATA_TOO_LARGE 113
851 #define RSA_R_DATA_TOO_LARGE_FOR_KEY_SIZE 114
852 #define RSA_R_DATA_TOO_LARGE_FOR_MODULUS 115
853 #define RSA_R_DATA_TOO_SMALL 116
854 #define RSA_R_DATA_TOO_SMALL_FOR_KEY_SIZE 117
855 #define RSA_R_DIGEST_TOO_BIG_FOR_RSA_KEY 118
856 #define RSA_R_D_E_NOT_CONGRUENT_TO_1 119
857 #define RSA_R_EMPTY_PUBLIC_KEY 120
858 #define RSA_R_ENCODE_ERROR 121
859 #define RSA_R_FIRST_OCTET_INVALID 122
860 #define RSA_R_INCONSISTENT_SET_OF_CRT_VALUES 123
861 #define RSA_R_INTERNAL_ERROR 124
862 #define RSA_R_INVALID_MESSAGE_LENGTH 125
863 #define RSA_R_KEY_SIZE_TOO_SMALL 126
864 #define RSA_R_LAST_OCTET_INVALID 127
865 #define RSA_R_MODULUS_TOO_LARGE 128
866 #define RSA_R_MUST_HAVE_AT_LEAST_TWO_PRIMES 129
867 #define RSA_R_NO_PUBLIC_EXPONENT 130
868 #define RSA_R_NULL_BEFORE_BLOCK_MISSING 131
869 #define RSA_R_N_NOT_EQUAL_P_Q 132
870 #define RSA_R_OAEP_DECODING_ERROR 133
871 #define RSA_R_ONLY_ONE_OF_P_Q_GIVEN 134
872 #define RSA_R_OUTPUT_BUFFER_TOO_SMALL 135
873 #define RSA_R_PADDING_CHECK_FAILED 136
874 #define RSA_R_PKCS_DECODING_ERROR 137
875 #define RSA_R_SLEN_CHECK_FAILED 138
876 #define RSA_R_SLEN_RECOVERY_FAILED 139
877 #define RSA_R_TOO_LONG 140
878 #define RSA_R_TOO_MANY_ITERATIONS 141
879 #define RSA_R_UNKNOWN_ALGORITHM_TYPE 142
880 #define RSA_R_UNKNOWN_PADDING_TYPE 143
881 #define RSA_R_VALUE_MISSING 144
882 #define RSA_R_WRONG_SIGNATURE_LENGTH 145
883 #define RSA_R_PUBLIC_KEY_VALIDATION_FAILED 146
884 #define RSA_R_D_OUT_OF_RANGE 147
885 #define RSA_R_BLOCK_TYPE_IS_NOT_02 148
886 
887 #endif  // OPENSSL_HEADER_RSA_H
888