2 * Copyright (C) 2011 Andre Noll <maan@systemlinux.org>
4 * Licensed under the GPL v2. For licencing details see COPYING.
7 /** \file gcrypt.c Libgrcypt-based encryption/decryption routines. */
17 #include "crypt_backend.h"
20 //#define GCRYPT_DEBUG 1
22 static bool libgcrypt_has_oaep
;
23 static const char *rsa_decrypt_sexp
;
26 static void dump_buffer(const char *msg
, unsigned char *buf
, int len
)
30 fprintf(stderr
, "%s (%u bytes): ", msg
, len
);
31 for (i
= 0; i
< len
; i
++)
32 fprintf(stderr
, "%02x ", buf
[i
]);
33 fprintf(stderr
, "\n");
36 /** Empty. Define GCRYPT_DEBUG to dump buffers. */
37 #define dump_buffer(a, b, c)
40 void hash_function(const char *data
, unsigned long len
, unsigned char *hash
)
46 gret
= gcry_md_open(&handle
, GCRY_MD_SHA1
, 0);
48 gcry_md_write(handle
, data
, (size_t)len
);
49 gcry_md_final(handle
);
50 md
= gcry_md_read(handle
, GCRY_MD_SHA1
);
52 memcpy(hash
, md
, HASH_SIZE
);
53 gcry_md_close(handle
);
56 void get_random_bytes_or_die(unsigned char *buf
, int num
)
58 gcry_randomize(buf
, (size_t)num
, GCRY_STRONG_RANDOM
);
62 * This is called at the beginning of every program that uses libgcrypt. We
63 * don't have to initialize any random seed here, but we must initialize the
64 * gcrypt library. This task is performed by gcry_check_version() which can
65 * also check that the gcrypt library version is at least the minimal required
66 * version. This function also tells us whether we have to use our own OAEP
69 void init_random_seed_or_die(void)
71 const char *ver
, *req_ver
;
73 ver
= gcry_check_version(NULL
);
75 if (!gcry_check_version(req_ver
)) {
76 PARA_EMERG_LOG("fatal: need at least libgcrypt-%s, have: %s\n",
81 if (gcry_check_version(req_ver
)) {
82 libgcrypt_has_oaep
= true;
83 rsa_decrypt_sexp
= "(enc-val(flags oaep)(rsa(a %m)))";
85 libgcrypt_has_oaep
= false;
86 rsa_decrypt_sexp
= "(enc-val(rsa(a %m)))";
90 /** S-expression for the public part of an RSA key. */
91 #define RSA_PUBKEY_SEXP "(public-key (rsa (n %m) (e %m)))"
92 /** S-expression for a private RSA key. */
93 #define RSA_PRIVKEY_SEXP "(private-key (rsa (n %m) (e %m) (d %m) (p %m) (q %m) (u %m)))"
95 /* rfc 3447, appendix B.2 */
96 static void mgf1(unsigned char *seed
, size_t seed_len
, unsigned result_len
,
97 unsigned char *result
)
103 unsigned char octet_string
[4], *rp
= result
, *end
= rp
+ result_len
;
105 assert(result_len
/ HASH_SIZE
< 1ULL << 31);
106 gret
= gcry_md_open(&handle
, GCRY_MD_SHA1
, 0);
108 for (n
= 0; rp
< end
; n
++) {
109 gcry_md_write(handle
, seed
, seed_len
);
110 octet_string
[0] = (unsigned char)((n
>> 24) & 255);
111 octet_string
[1] = (unsigned char)((n
>> 16) & 255);
112 octet_string
[2] = (unsigned char)((n
>> 8)) & 255;
113 octet_string
[3] = (unsigned char)(n
& 255);
114 gcry_md_write(handle
, octet_string
, 4);
115 gcry_md_final(handle
);
116 md
= gcry_md_read(handle
, GCRY_MD_SHA1
);
117 memcpy(rp
, md
, PARA_MIN(HASH_SIZE
, (int)(end
- rp
)));
119 gcry_md_reset(handle
);
121 gcry_md_close(handle
);
124 /** The sha1 hash of an empty file. */
125 static const unsigned char empty_hash
[HASH_SIZE
] =
126 "\xda" "\x39" "\xa3" "\xee" "\x5e"
127 "\x6b" "\x4b" "\x0d" "\x32" "\x55"
128 "\xbf" "\xef" "\x95" "\x60" "\x18"
129 "\x90" "\xaf" "\xd8" "\x07" "\x09";
131 /* rfc3447, section 7.1.1 */
132 static void pad_oaep(unsigned char *in
, size_t in_len
, unsigned char *out
,
135 size_t ps_len
= out_len
- in_len
- 2 * HASH_SIZE
- 2;
136 size_t n
, mask_len
= out_len
- HASH_SIZE
- 1;
137 unsigned char *seed
= out
+ 1, *db
= seed
+ HASH_SIZE
,
138 *ps
= db
+ HASH_SIZE
, *one
= ps
+ ps_len
;
139 unsigned char *db_mask
, seed_mask
[HASH_SIZE
];
141 assert(in_len
<= out_len
- 2 - 2 * HASH_SIZE
);
142 assert(out_len
> 2 * HASH_SIZE
+ 2);
143 PARA_DEBUG_LOG("padding %zu byte input -> %zu byte output\n",
145 dump_buffer("unpadded buffer", in
, in_len
);
148 get_random_bytes_or_die(seed
, HASH_SIZE
);
149 memcpy(db
, empty_hash
, HASH_SIZE
);
150 memset(ps
, 0, ps_len
);
152 memcpy(one
+ 1, in
, in_len
);
153 db_mask
= para_malloc(mask_len
);
154 mgf1(seed
, HASH_SIZE
, mask_len
, db_mask
);
155 for (n
= 0; n
< mask_len
; n
++)
157 mgf1(db
, mask_len
, HASH_SIZE
, seed_mask
);
158 for (n
= 0; n
< HASH_SIZE
; n
++)
159 seed
[n
] ^= seed_mask
[n
];
161 dump_buffer("padded buffer", out
, out_len
);
164 /* rfc 3447, section 7.1.2 */
165 static int unpad_oaep(unsigned char *in
, size_t in_len
, unsigned char *out
,
168 unsigned char *masked_seed
= in
+ 1;
169 unsigned char *db
= in
+ 1 + HASH_SIZE
;
170 unsigned char seed
[HASH_SIZE
], seed_mask
[HASH_SIZE
];
171 unsigned char *db_mask
, *p
;
172 size_t n
, mask_len
= in_len
- HASH_SIZE
- 1;
174 mgf1(db
, mask_len
, HASH_SIZE
, seed_mask
);
175 for (n
= 0; n
< HASH_SIZE
; n
++)
176 seed
[n
] = masked_seed
[n
] ^ seed_mask
[n
];
177 db_mask
= para_malloc(mask_len
);
178 mgf1(seed
, HASH_SIZE
, mask_len
, db_mask
);
179 for (n
= 0; n
< mask_len
; n
++)
182 if (memcmp(db
, empty_hash
, HASH_SIZE
))
184 for (p
= db
+ HASH_SIZE
; p
< in
+ in_len
- 1; p
++)
187 if (p
>= in
+ in_len
- 1)
190 *out_len
= in
+ in_len
- p
;
191 memcpy(out
, p
, *out_len
);
195 struct asymmetric_key
{
200 static const char *gcrypt_strerror(gcry_error_t gret
)
202 return gcry_strerror(gcry_err_code(gret
));
205 static int decode_key(const char *key_file
, const char *header_str
,
206 const char *footer_str
, unsigned char **result
)
210 size_t map_size
, key_size
, blob_size
;
211 unsigned char *blob
= NULL
;
212 char *begin
, *footer
, *key
;
214 ret
= mmap_full_file(key_file
, O_RDONLY
, &map
, &map_size
, NULL
);
218 if (strncmp(map
, header_str
, strlen(header_str
)))
220 footer
= strstr(map
, footer_str
);
224 begin
= map
+ strlen(header_str
);
225 /* skip whitespace at the beginning */
226 for (; begin
< footer
; begin
++) {
227 if (para_isspace(*begin
))
235 key_size
= footer
- begin
;
236 key
= para_malloc(key_size
+ 1);
237 for (i
= 0, j
= 0; begin
+ i
< footer
; i
++) {
238 if (para_isspace(begin
[i
]))
243 //PARA_CRIT_LOG("key: %s\n", key);
244 blob_size
= key_size
* 2;
245 blob
= para_malloc(blob_size
);
246 ret
= base64_decode(key
, blob
, blob_size
);
255 ret2
= para_munmap(map
, map_size
);
256 if (ret
>= 0 && ret2
< 0)
266 /** ASN Types and their code. */
268 /** The next object is an integer. */
269 ASN1_TYPE_INTEGER
= 0x2,
270 /** Bit string object. */
271 ASN1_TYPE_BIT_STRING
= 0x03,
272 /** Keys start with one big type sequence. */
273 ASN1_TYPE_SEQUENCE
= 0x30,
276 /* bit 6 has value 0 */
277 static inline bool is_primitive(unsigned char c
)
279 return ((c
& (1<<6)) == 0);
282 static inline bool is_primitive_integer(unsigned char c
)
284 if (!is_primitive(c
))
286 return ((c
& 0x1f) == ASN1_TYPE_INTEGER
);
289 /* Bit 8 is zero (and bits 7-1 give the length) */
290 static inline bool is_short_form(unsigned char c
)
292 return (c
& 0x80) == 0;
295 static inline int get_short_form_length(unsigned char c
)
300 static inline int get_long_form_num_length_bytes(unsigned char c
)
305 static int find_pubkey_bignum_offset(const unsigned char *data
, int len
)
307 const unsigned char *p
= data
, *end
= data
+ len
;
309 /* the whole thing istarts with one sequence */
310 if (*p
!= ASN1_TYPE_SEQUENCE
)
311 return -E_ASN1_PARSE
;
314 return -E_ASN1_PARSE
;
315 if (is_short_form(*p
))
318 p
+= 1 + get_long_form_num_length_bytes(*p
);
320 return -E_ASN1_PARSE
;
321 /* another sequence containing the object id, skip it */
322 if (*p
!= ASN1_TYPE_SEQUENCE
)
323 return -E_ASN1_PARSE
;
326 return -E_ASN1_PARSE
;
327 if (!is_short_form(*p
))
328 return -E_ASN1_PARSE
;
329 p
+= 1 + get_short_form_length(*p
);
331 return -E_ASN1_PARSE
;
332 /* all numbers are wrapped in a bit string object that follows */
333 if (*p
!= ASN1_TYPE_BIT_STRING
)
334 return -E_ASN1_PARSE
;
337 return -E_ASN1_PARSE
;
338 if (is_short_form(*p
))
341 p
+= 1 + get_long_form_num_length_bytes(*p
);
342 p
++; /* skip number of unused bits in the bit string */
344 return -E_ASN1_PARSE
;
346 /* next, we have a sequence of two integers (n and e) */
347 if (*p
!= ASN1_TYPE_SEQUENCE
)
348 return -E_ASN1_PARSE
;
351 return -E_ASN1_PARSE
;
352 if (is_short_form(*p
))
355 p
+= 1 + get_long_form_num_length_bytes(*p
);
357 return -E_ASN1_PARSE
;
358 if (*p
!= ASN1_TYPE_INTEGER
)
359 return -E_ASN1_PARSE
;
364 * Returns: Number of bytes scanned. This may differ from the value returned via
365 * bn_bytes because the latter does not include the ASN.1 prefix and a leading
366 * zero is not considered as an additional byte for bn_bytes.
368 static int read_bignum(unsigned char *start
, unsigned char *end
, gcry_mpi_t
*bn
,
373 unsigned char *cp
= start
;
375 if (!is_primitive_integer(*cp
))
376 return -E_BAD_PRIVATE_KEY
;
378 if (is_short_form(*cp
)) {
379 bn_size
= get_short_form_length(*cp
);
382 int num_bytes
= get_long_form_num_length_bytes(*cp
);
383 if (cp
+ num_bytes
> end
)
384 return -E_BAD_PRIVATE_KEY
;
385 if (num_bytes
> 4) /* nobody has such a large modulus */
386 return -E_BAD_PRIVATE_KEY
;
389 for (i
= 0; i
< num_bytes
; i
++, cp
++)
390 bn_size
= (bn_size
<< 8) + *cp
;
392 PARA_DEBUG_LOG("bn_size %d (0x%x)\n", bn_size
, bn_size
);
393 gret
= gcry_mpi_scan(bn
, GCRYMPI_FMT_STD
, cp
, bn_size
, NULL
);
395 PARA_ERROR_LOG("%s while scanning n\n",
396 gcry_strerror(gcry_err_code(gret
)));
400 * Don't take the first leading zero into account for the size of the
410 // unsigned char *buf;
411 // gcry_mpi_aprint(GCRYMPI_FMT_HEX, &buf, NULL, *bn);
412 // PARA_CRIT_LOG("bn: %s\n", buf);
416 static int find_privkey_bignum_offset(const unsigned char *data
, int len
)
418 const unsigned char *p
= data
, *end
= data
+ len
;
420 /* like the public key, the whole thing is contained in a sequence */
421 if (*p
!= ASN1_TYPE_SEQUENCE
)
422 return -E_ASN1_PARSE
;
425 return -E_ASN1_PARSE
;
426 if (is_short_form(*p
))
429 p
+= 1 + get_long_form_num_length_bytes(*p
);
431 return -E_ASN1_PARSE
;
433 /* Skip next integer */
434 if (*p
!= ASN1_TYPE_INTEGER
)
435 return -E_ASN1_PARSE
;
438 return -E_ASN1_PARSE
;
439 if (is_short_form(*p
))
440 p
+= 1 + get_short_form_length(*p
);
442 p
+= 1 + get_long_form_num_length_bytes(*p
);
444 return -E_ASN1_PARSE
;
448 /** Private keys start with this header. */
449 #define PRIVATE_KEY_HEADER "-----BEGIN RSA PRIVATE KEY-----"
450 /** Private keys end with this footer. */
451 #define PRIVATE_KEY_FOOTER "-----END RSA PRIVATE KEY-----"
453 static int get_private_key(const char *key_file
, struct asymmetric_key
**result
)
455 gcry_mpi_t n
= NULL
, e
= NULL
, d
= NULL
, p
= NULL
, q
= NULL
,
457 unsigned char *blob
, *cp
, *end
;
458 int blob_size
, ret
, n_size
;
462 struct asymmetric_key
*key
;
464 ret
= decode_key(key_file
, PRIVATE_KEY_HEADER
, PRIVATE_KEY_FOOTER
,
469 end
= blob
+ blob_size
;
470 ret
= find_privkey_bignum_offset(blob
, blob_size
);
473 PARA_INFO_LOG("reading RSA params at offset %d\n", ret
);
476 ret
= read_bignum(cp
, end
, &n
, &n_size
);
481 ret
= read_bignum(cp
, end
, &e
, NULL
);
486 ret
= read_bignum(cp
, end
, &d
, NULL
);
491 ret
= read_bignum(cp
, end
, &p
, NULL
);
496 ret
= read_bignum(cp
, end
, &q
, NULL
);
500 ret
= read_bignum(cp
, end
, &u
, NULL
);
505 * OpenSSL uses slightly different parameters than gcrypt. To use these
506 * parameters we need to swap the values of p and q and recompute u.
508 if (gcry_mpi_cmp(p
, q
) > 0) {
510 gcry_mpi_invm(u
, p
, q
);
512 gret
= gcry_sexp_build(&sexp
, &erroff
, RSA_PRIVKEY_SEXP
,
516 PARA_ERROR_LOG("offset %zu: %s\n", erroff
,
517 gcry_strerror(gcry_err_code(gret
)));
521 key
= para_malloc(sizeof(*key
));
525 PARA_INFO_LOG("succesfully read %d bit private key\n", ret
);
543 /** Public keys start with this header. */
544 #define PUBLIC_KEY_HEADER "-----BEGIN PUBLIC KEY-----"
545 /** Public keys end with this footer. */
546 #define PUBLIC_KEY_FOOTER "-----END PUBLIC KEY-----"
548 static int get_asn_public_key(const char *key_file
, struct asymmetric_key
**result
)
550 gcry_mpi_t n
= NULL
, e
= NULL
;
551 unsigned char *blob
, *cp
, *end
;
552 int blob_size
, ret
, n_size
;
556 struct asymmetric_key
*key
;
558 ret
= decode_key(key_file
, PUBLIC_KEY_HEADER
, PUBLIC_KEY_FOOTER
,
563 end
= blob
+ blob_size
;
564 ret
= find_pubkey_bignum_offset(blob
, blob_size
);
567 PARA_DEBUG_LOG("decoding public RSA params at offset %d\n", ret
);
570 ret
= read_bignum(cp
, end
, &n
, &n_size
);
575 ret
= read_bignum(cp
, end
, &e
, NULL
);
580 gret
= gcry_sexp_build(&sexp
, &erroff
, RSA_PUBKEY_SEXP
, n
, e
);
582 PARA_ERROR_LOG("offset %zu: %s\n", erroff
,
583 gcry_strerror(gcry_err_code(gret
)));
587 key
= para_malloc(sizeof(*key
));
591 PARA_INFO_LOG("successfully read %u bit asn public key\n", n_size
* 8);
602 static int get_ssh_public_key(unsigned char *data
, int size
, gcry_sexp_t
*result
)
606 unsigned char *blob
= NULL
, *p
, *end
;
607 size_t nr_scanned
, erroff
, decoded_size
;
608 gcry_mpi_t e
= NULL
, n
= NULL
;
610 PARA_DEBUG_LOG("decoding %d byte public rsa-ssh key\n", size
);
611 if (size
> INT_MAX
/ 4)
612 return -ERRNO_TO_PARA_ERROR(EOVERFLOW
);
613 blob
= para_malloc(2 * size
);
614 ret
= uudecode((char *)data
, blob
, 2 * size
);
618 end
= blob
+ decoded_size
;
619 dump_buffer("decoded key", blob
, decoded_size
);
620 ret
= check_ssh_key_header(blob
, decoded_size
);
627 PARA_DEBUG_LOG("scanning modulus and public exponent\n");
628 gret
= gcry_mpi_scan(&e
, GCRYMPI_FMT_SSH
, p
, end
- p
, &nr_scanned
);
631 PARA_CRIT_LOG("%s\n", gcry_strerror(gcry_err_code(gret
)));
634 PARA_DEBUG_LOG("scanned e (%zu bytes)\n", nr_scanned
);
635 // gcry_mpi_aprint(GCRYMPI_FMT_HEX, &buf, NULL, rsa_e);
636 // PARA_CRIT_LOG("e: %s\n", buf);
640 gret
= gcry_mpi_scan(&n
, GCRYMPI_FMT_SSH
, p
, end
- p
, &nr_scanned
);
643 PARA_ERROR_LOG("%s\n", gcry_strerror(gcry_err_code(gret
)));
646 PARA_DEBUG_LOG("scanned n (%zu bytes)\n", nr_scanned
);
647 // gcry_mpi_aprint(GCRYMPI_FMT_HEX, &buf, NULL, rsa_n);
648 // PARA_CRIT_LOG("n: %s\n", buf);
649 gret
= gcry_sexp_build(result
, &erroff
, RSA_PUBKEY_SEXP
, n
, e
);
651 PARA_ERROR_LOG("offset %zu: %s\n", erroff
,
652 gcry_strerror(gcry_err_code(gret
)));
656 ret
= nr_scanned
/ 32 * 32;
657 PARA_INFO_LOG("successfully read %u bit ssh public key\n", ret
* 8);
667 int get_asymmetric_key(const char *key_file
, int private,
668 struct asymmetric_key
**result
)
673 unsigned char *start
, *end
;
675 struct asymmetric_key
*key
;
678 return get_private_key(key_file
, result
);
679 ret
= mmap_full_file(key_file
, O_RDONLY
, &map
, &map_size
, NULL
);
682 ret
= is_ssh_rsa_key(map
, map_size
);
684 ret
= para_munmap(map
, map_size
);
687 return get_asn_public_key(key_file
, result
);
690 end
= map
+ map_size
;
694 ret
= get_ssh_public_key(start
, end
- start
, &sexp
);
697 key
= para_malloc(sizeof(*key
));
698 key
->num_bytes
= ret
;
701 ret
= key
->num_bytes
;
703 ret2
= para_munmap(map
, map_size
);
704 if (ret
>= 0 && ret2
< 0)
709 void free_asymmetric_key(struct asymmetric_key
*key
)
713 gcry_sexp_release(key
->sexp
);
717 static int decode_rsa(gcry_sexp_t sexp
, int key_size
, unsigned char *outbuf
,
722 unsigned char oaep_buf
[512];
725 if (libgcrypt_has_oaep
) {
726 const char *p
= gcry_sexp_nth_data(sexp
, 1, nbytes
);
729 PARA_ERROR_LOG("could not get data from list\n");
732 memcpy(outbuf
, p
, *nbytes
);
735 out_mpi
= gcry_sexp_nth_mpi(sexp
, 0, GCRYMPI_FMT_USG
);
738 gret
= gcry_mpi_print(GCRYMPI_FMT_USG
, oaep_buf
, sizeof(oaep_buf
),
741 PARA_ERROR_LOG("mpi_print: %s\n", gcrypt_strerror(gret
));
743 goto out_mpi_release
;
746 * An oaep-encoded buffer always starts with at least one zero byte.
747 * However, leading zeroes in an mpi are omitted in the output of
748 * gcry_mpi_print() when using the GCRYMPI_FMT_USG format. The
749 * alternative, GCRYMPI_FMT_STD, does not work either because here the
750 * leading zero(es) might also be omitted, depending on the value of
753 * To circumvent this, we shift the oaep buffer to the right. But first
754 * we check that the buffer actually started with a zero byte, i.e. that
755 * nbytes < key_size. Otherwise a decoding error occurred.
757 ret
= -E_SEXP_DECRYPT
;
758 if (*nbytes
>= key_size
)
759 goto out_mpi_release
;
760 memmove(oaep_buf
+ key_size
- *nbytes
, oaep_buf
, *nbytes
);
761 memset(oaep_buf
, 0, key_size
- *nbytes
);
763 PARA_DEBUG_LOG("decrypted buffer before unpad (%d bytes):\n",
765 dump_buffer("non-unpadded decrypted buffer", oaep_buf
, key_size
);;
766 unpad_oaep(oaep_buf
, key_size
, outbuf
, nbytes
);
767 PARA_DEBUG_LOG("decrypted buffer after unpad (%zu bytes):\n",
769 dump_buffer("unpadded decrypted buffer", outbuf
, *nbytes
);;
772 gcry_mpi_release(out_mpi
);
776 int priv_decrypt(const char *key_file
, unsigned char *outbuf
,
777 unsigned char *inbuf
, int inlen
)
781 struct asymmetric_key
*priv
;
782 gcry_mpi_t in_mpi
= NULL
;
783 gcry_sexp_t in
, out
, priv_key
;
786 PARA_INFO_LOG("decrypting %d byte input\n", inlen
);
787 /* key_file -> asymmetric key priv */
788 ret
= get_private_key(key_file
, &priv
);
793 /* asymmetric key priv -> sexp priv_key */
795 priv_key
= gcry_sexp_find_token(priv
->sexp
, "private-key", 0);
799 /* inbuf -> in_mpi */
800 gret
= gcry_mpi_scan(&in_mpi
, GCRYMPI_FMT_USG
, inbuf
,
803 PARA_ERROR_LOG("%s\n", gcrypt_strerror(gret
));
807 /* in_mpi -> in sexp */
808 gret
= gcry_sexp_build(&in
, NULL
, rsa_decrypt_sexp
, in_mpi
);
810 PARA_ERROR_LOG("%s\n", gcrypt_strerror(gret
));
815 /* rsa decryption: in sexp -> out sexp */
816 gret
= gcry_pk_decrypt(&out
, in
, priv_key
);
818 PARA_ERROR_LOG("decrypt: %s\n", gcrypt_strerror(gret
));
819 ret
= -E_SEXP_DECRYPT
;
822 ret
= decode_rsa(out
, key_size
, outbuf
, &nbytes
);
825 PARA_INFO_LOG("successfully decrypted %zu byte message\n", nbytes
);
828 gcry_sexp_release(out
);
830 gcry_sexp_release(in
);
832 gcry_mpi_release(in_mpi
);
834 gcry_sexp_release(priv_key
);
836 free_asymmetric_key(priv
);
840 int pub_encrypt(struct asymmetric_key
*pub
, unsigned char *inbuf
,
841 unsigned len
, unsigned char *outbuf
)
844 gcry_sexp_t pub_key
, in
, out
, out_a
;
845 gcry_mpi_t out_mpi
= NULL
;
849 PARA_INFO_LOG("encrypting %u byte input with %d-byte key\n", len
, pub
->num_bytes
);
852 pub_key
= gcry_sexp_find_token(pub
->sexp
, "public-key", 0);
855 if (libgcrypt_has_oaep
) {
856 gret
= gcry_sexp_build(&in
, NULL
,
857 "(data(flags oaep)(value %b))", len
, inbuf
);
859 unsigned char padded_input
[256];
860 const size_t pad_size
= 256;
861 /* inbuf -> padded inbuf */
862 pad_oaep(inbuf
, len
, padded_input
, pad_size
);
863 /* padded inbuf -> in sexp */
864 gret
= gcry_sexp_build(&in
, NULL
,
865 "(data(flags raw)(value %b))", pad_size
, padded_input
);
868 PARA_ERROR_LOG("%s\n", gcrypt_strerror(gret
));
872 /* rsa sexp encryption: in -> out */
873 gret
= gcry_pk_encrypt(&out
, in
, pub_key
);
875 PARA_ERROR_LOG("%s\n", gcrypt_strerror(gret
));
876 ret
= -E_SEXP_ENCRYPT
;
879 /* extract a, an MPI with the result of the RSA operation */
881 out_a
= gcry_sexp_find_token(out
, "a", 0);
884 /* convert sexp out_a -> out_mpi */
885 out_mpi
= gcry_sexp_nth_mpi(out_a
, 1, GCRYMPI_FMT_USG
);
890 gret
= gcry_mpi_print(GCRYMPI_FMT_USG
, outbuf
, 512 /* FIXME */, &nbytes
, out_mpi
);
892 PARA_ERROR_LOG("%s\n", gcrypt_strerror(gret
));
893 ret
= -E_SEXP_ENCRYPT
;
894 goto out_mpi_release
;
896 PARA_INFO_LOG("encrypted buffer is %zu bytes\n", nbytes
);
897 dump_buffer("enc buf", outbuf
, nbytes
);
901 gcry_mpi_release(out_mpi
);
903 gcry_sexp_release(out_a
);
905 gcry_sexp_release(out
);
907 gcry_sexp_release(in
);
909 gcry_sexp_release(pub_key
);
913 struct stream_cipher
{
914 gcry_cipher_hd_t handle
;
917 struct stream_cipher
*sc_new(const unsigned char *data
, int len
)
921 struct stream_cipher
*sc
= para_malloc(sizeof(*sc
));
922 gret
= gcry_cipher_open(&sc
->handle
, GCRY_CIPHER_ARCFOUR
,
923 GCRY_CIPHER_MODE_STREAM
, 0);
925 PARA_ERROR_LOG("%s\n", gcrypt_strerror(gret
));
929 gret
= gcry_cipher_setkey(sc
->handle
, data
, (size_t)len
);
934 void sc_free(struct stream_cipher
*sc
)
938 gcry_cipher_close(sc
->handle
);
942 int sc_send_bin_buffer(struct stream_cipher_context
*scc
, char *buf
,
947 unsigned char *tmp
= para_malloc(size
);
950 gret
= gcry_cipher_encrypt(scc
->send
->handle
, tmp
, size
,
951 (unsigned char *)buf
, size
);
953 ret
= write_all(scc
->fd
, (char *)tmp
, &size
);
958 int sc_recv_bin_buffer(struct stream_cipher_context
*scc
, char *buf
,
962 ssize_t ret
= recv(scc
->fd
, buf
, size
, 0);
965 ret
= -ERRNO_TO_PARA_ERROR(errno
);
968 /* perform in-place encryption */
969 gret
= gcry_cipher_encrypt(scc
->recv
->handle
, (unsigned char *)buf
, ret
,