2 * Copyright (C) 2011-2013 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. */
16 #include "crypt_backend.h"
19 //#define GCRYPT_DEBUG 1
21 static bool libgcrypt_has_oaep;
22 static const char *rsa_decrypt_sexp;
25 static void dump_buffer(const char *msg, unsigned char *buf, int len)
29 fprintf(stderr, "%s (%u bytes): ", msg, len);
30 for (i = 0; i < len; i++)
31 fprintf(stderr, "%02x ", buf[i]);
32 fprintf(stderr, "\n");
35 /** Empty. Define GCRYPT_DEBUG to dump buffers. */
36 #define dump_buffer(a, b, c)
39 void hash_function(const char *data, unsigned long len, unsigned char *hash)
45 gret = gcry_md_open(&handle, GCRY_MD_SHA1, 0);
47 gcry_md_write(handle, data, (size_t)len);
48 gcry_md_final(handle);
49 md = gcry_md_read(handle, GCRY_MD_SHA1);
51 memcpy(hash, md, HASH_SIZE);
52 gcry_md_close(handle);
55 void get_random_bytes_or_die(unsigned char *buf, int num)
57 gcry_randomize(buf, (size_t)num, GCRY_STRONG_RANDOM);
61 * This is called at the beginning of every program that uses libgcrypt. We
62 * don't have to initialize any random seed here, but we must initialize the
63 * gcrypt library. This task is performed by gcry_check_version() which can
64 * also check that the gcrypt library version is at least the minimal required
65 * version. This function also tells us whether we have to use our own OAEP
68 void init_random_seed_or_die(void)
70 const char *ver, *req_ver;
72 ver = gcry_check_version(NULL);
74 if (!gcry_check_version(req_ver)) {
75 PARA_EMERG_LOG("fatal: need at least libgcrypt-%s, have: %s\n",
80 if (gcry_check_version(req_ver)) {
81 libgcrypt_has_oaep = true;
82 rsa_decrypt_sexp = "(enc-val(flags oaep)(rsa(a %m)))";
84 libgcrypt_has_oaep = false;
85 rsa_decrypt_sexp = "(enc-val(rsa(a %m)))";
89 /** S-expression for the public part of an RSA key. */
90 #define RSA_PUBKEY_SEXP "(public-key (rsa (n %m) (e %m)))"
91 /** S-expression for a private RSA key. */
92 #define RSA_PRIVKEY_SEXP "(private-key (rsa (n %m) (e %m) (d %m) (p %m) (q %m) (u %m)))"
94 /* rfc 3447, appendix B.2 */
95 static void mgf1(unsigned char *seed, size_t seed_len, unsigned result_len,
96 unsigned char *result)
102 unsigned char octet_string[4], *rp = result, *end = rp + result_len;
104 assert(result_len / HASH_SIZE < 1ULL << 31);
105 gret = gcry_md_open(&handle, GCRY_MD_SHA1, 0);
107 for (n = 0; rp < end; n++) {
108 gcry_md_write(handle, seed, seed_len);
109 octet_string[0] = (unsigned char)((n >> 24) & 255);
110 octet_string[1] = (unsigned char)((n >> 16) & 255);
111 octet_string[2] = (unsigned char)((n >> 8)) & 255;
112 octet_string[3] = (unsigned char)(n & 255);
113 gcry_md_write(handle, octet_string, 4);
114 gcry_md_final(handle);
115 md = gcry_md_read(handle, GCRY_MD_SHA1);
116 memcpy(rp, md, PARA_MIN(HASH_SIZE, (int)(end - rp)));
118 gcry_md_reset(handle);
120 gcry_md_close(handle);
123 /** The sha1 hash of an empty file. */
124 static const unsigned char empty_hash[HASH_SIZE] =
125 "\xda" "\x39" "\xa3" "\xee" "\x5e"
126 "\x6b" "\x4b" "\x0d" "\x32" "\x55"
127 "\xbf" "\xef" "\x95" "\x60" "\x18"
128 "\x90" "\xaf" "\xd8" "\x07" "\x09";
130 /* rfc3447, section 7.1.1 */
131 static void pad_oaep(unsigned char *in, size_t in_len, unsigned char *out,
134 size_t ps_len = out_len - in_len - 2 * HASH_SIZE - 2;
135 size_t n, mask_len = out_len - HASH_SIZE - 1;
136 unsigned char *seed = out + 1, *db = seed + HASH_SIZE,
137 *ps = db + HASH_SIZE, *one = ps + ps_len;
138 unsigned char *db_mask, seed_mask[HASH_SIZE];
140 assert(in_len <= out_len - 2 - 2 * HASH_SIZE);
141 assert(out_len > 2 * HASH_SIZE + 2);
142 PARA_DEBUG_LOG("padding %zu byte input -> %zu byte output\n",
144 dump_buffer("unpadded buffer", in, in_len);
147 get_random_bytes_or_die(seed, HASH_SIZE);
148 memcpy(db, empty_hash, HASH_SIZE);
149 memset(ps, 0, ps_len);
151 memcpy(one + 1, in, in_len);
152 db_mask = para_malloc(mask_len);
153 mgf1(seed, HASH_SIZE, mask_len, db_mask);
154 for (n = 0; n < mask_len; n++)
156 mgf1(db, mask_len, HASH_SIZE, seed_mask);
157 for (n = 0; n < HASH_SIZE; n++)
158 seed[n] ^= seed_mask[n];
160 dump_buffer("padded buffer", out, out_len);
163 /* rfc 3447, section 7.1.2 */
164 static int unpad_oaep(unsigned char *in, size_t in_len, unsigned char *out,
167 unsigned char *masked_seed = in + 1;
168 unsigned char *db = in + 1 + HASH_SIZE;
169 unsigned char seed[HASH_SIZE], seed_mask[HASH_SIZE];
170 unsigned char *db_mask, *p;
171 size_t n, mask_len = in_len - HASH_SIZE - 1;
173 mgf1(db, mask_len, HASH_SIZE, seed_mask);
174 for (n = 0; n < HASH_SIZE; n++)
175 seed[n] = masked_seed[n] ^ seed_mask[n];
176 db_mask = para_malloc(mask_len);
177 mgf1(seed, HASH_SIZE, mask_len, db_mask);
178 for (n = 0; n < mask_len; n++)
181 if (memcmp(db, empty_hash, HASH_SIZE))
183 for (p = db + HASH_SIZE; p < in + in_len - 1; p++)
186 if (p >= in + in_len - 1)
189 *out_len = in + in_len - p;
190 memcpy(out, p, *out_len);
194 struct asymmetric_key {
199 static const char *gcrypt_strerror(gcry_error_t gret)
201 return gcry_strerror(gcry_err_code(gret));
204 static int decode_key(const char *key_file, const char *header_str,
205 const char *footer_str, unsigned char **result)
209 size_t map_size, key_size, blob_size;
210 unsigned char *blob = NULL;
211 char *begin, *footer, *key;
213 ret = mmap_full_file(key_file, O_RDONLY, &map, &map_size, NULL);
217 if (strncmp(map, header_str, strlen(header_str)))
219 footer = strstr(map, footer_str);
223 begin = map + strlen(header_str);
224 /* skip whitespace at the beginning */
225 for (; begin < footer; begin++) {
226 if (para_isspace(*begin))
234 key_size = footer - begin;
235 key = para_malloc(key_size + 1);
236 for (i = 0, j = 0; begin + i < footer; i++) {
237 if (para_isspace(begin[i]))
242 //PARA_CRIT_LOG("key: %s\n", key);
243 blob_size = key_size * 2;
244 blob = para_malloc(blob_size);
245 ret = base64_decode(key, blob, blob_size);
254 ret2 = para_munmap(map, map_size);
255 if (ret >= 0 && ret2 < 0)
265 /** ASN Types and their code. */
267 /** The next object is an integer. */
268 ASN1_TYPE_INTEGER = 0x2,
269 /** Bit string object. */
270 ASN1_TYPE_BIT_STRING = 0x03,
271 /** Keys start with one big type sequence. */
272 ASN1_TYPE_SEQUENCE = 0x30,
275 /* bit 6 has value 0 */
276 static inline bool is_primitive(unsigned char c)
278 return ((c & (1<<6)) == 0);
281 static inline bool is_primitive_integer(unsigned char c)
283 if (!is_primitive(c))
285 return ((c & 0x1f) == ASN1_TYPE_INTEGER);
288 /* Bit 8 is zero (and bits 7-1 give the length) */
289 static inline bool is_short_form(unsigned char c)
291 return (c & 0x80) == 0;
294 static inline int get_short_form_length(unsigned char c)
299 static inline int get_long_form_num_length_bytes(unsigned char c)
304 static int find_pubkey_bignum_offset(const unsigned char *data, int len)
306 const unsigned char *p = data, *end = data + len;
308 /* the whole thing istarts with one sequence */
309 if (*p != ASN1_TYPE_SEQUENCE)
310 return -E_ASN1_PARSE;
313 return -E_ASN1_PARSE;
314 if (is_short_form(*p))
317 p += 1 + get_long_form_num_length_bytes(*p);
319 return -E_ASN1_PARSE;
320 /* another sequence containing the object id, skip it */
321 if (*p != ASN1_TYPE_SEQUENCE)
322 return -E_ASN1_PARSE;
325 return -E_ASN1_PARSE;
326 if (!is_short_form(*p))
327 return -E_ASN1_PARSE;
328 p += 1 + get_short_form_length(*p);
330 return -E_ASN1_PARSE;
331 /* all numbers are wrapped in a bit string object that follows */
332 if (*p != ASN1_TYPE_BIT_STRING)
333 return -E_ASN1_PARSE;
336 return -E_ASN1_PARSE;
337 if (is_short_form(*p))
340 p += 1 + get_long_form_num_length_bytes(*p);
341 p++; /* skip number of unused bits in the bit string */
343 return -E_ASN1_PARSE;
345 /* next, we have a sequence of two integers (n and e) */
346 if (*p != ASN1_TYPE_SEQUENCE)
347 return -E_ASN1_PARSE;
350 return -E_ASN1_PARSE;
351 if (is_short_form(*p))
354 p += 1 + get_long_form_num_length_bytes(*p);
356 return -E_ASN1_PARSE;
357 if (*p != ASN1_TYPE_INTEGER)
358 return -E_ASN1_PARSE;
363 * Returns: Number of bytes scanned. This may differ from the value returned via
364 * bn_bytes because the latter does not include the ASN.1 prefix and a leading
365 * zero is not considered as an additional byte for bn_bytes.
367 static int read_bignum(unsigned char *start, unsigned char *end, gcry_mpi_t *bn,
372 unsigned char *cp = start;
374 if (!is_primitive_integer(*cp))
375 return -E_BAD_PRIVATE_KEY;
377 if (is_short_form(*cp)) {
378 bn_size = get_short_form_length(*cp);
381 int num_bytes = get_long_form_num_length_bytes(*cp);
382 if (cp + num_bytes > end)
383 return -E_BAD_PRIVATE_KEY;
384 if (num_bytes > 4) /* nobody has such a large modulus */
385 return -E_BAD_PRIVATE_KEY;
388 for (i = 0; i < num_bytes; i++, cp++)
389 bn_size = (bn_size << 8) + *cp;
391 PARA_DEBUG_LOG("bn_size %d (0x%x)\n", bn_size, bn_size);
392 gret = gcry_mpi_scan(bn, GCRYMPI_FMT_STD, cp, bn_size, NULL);
394 PARA_ERROR_LOG("%s while scanning n\n",
395 gcry_strerror(gcry_err_code(gret)));
399 * Don't take the first leading zero into account for the size of the
409 // unsigned char *buf;
410 // gcry_mpi_aprint(GCRYMPI_FMT_HEX, &buf, NULL, *bn);
411 // PARA_CRIT_LOG("bn: %s\n", buf);
415 static int find_privkey_bignum_offset(const unsigned char *data, int len)
417 const unsigned char *p = data, *end = data + len;
419 /* like the public key, the whole thing is contained in a sequence */
420 if (*p != ASN1_TYPE_SEQUENCE)
421 return -E_ASN1_PARSE;
424 return -E_ASN1_PARSE;
425 if (is_short_form(*p))
428 p += 1 + get_long_form_num_length_bytes(*p);
430 return -E_ASN1_PARSE;
432 /* Skip next integer */
433 if (*p != ASN1_TYPE_INTEGER)
434 return -E_ASN1_PARSE;
437 return -E_ASN1_PARSE;
438 if (is_short_form(*p))
439 p += 1 + get_short_form_length(*p);
441 p += 1 + get_long_form_num_length_bytes(*p);
443 return -E_ASN1_PARSE;
447 /** Private keys start with this header. */
448 #define PRIVATE_KEY_HEADER "-----BEGIN RSA PRIVATE KEY-----"
449 /** Private keys end with this footer. */
450 #define PRIVATE_KEY_FOOTER "-----END RSA PRIVATE KEY-----"
452 static int get_private_key(const char *key_file, struct asymmetric_key **result)
454 gcry_mpi_t n = NULL, e = NULL, d = NULL, p = NULL, q = NULL,
456 unsigned char *blob, *cp, *end;
457 int blob_size, ret, n_size;
461 struct asymmetric_key *key;
463 ret = decode_key(key_file, PRIVATE_KEY_HEADER, PRIVATE_KEY_FOOTER,
468 end = blob + blob_size;
469 ret = find_privkey_bignum_offset(blob, blob_size);
472 PARA_INFO_LOG("reading RSA params at offset %d\n", ret);
475 ret = read_bignum(cp, end, &n, &n_size);
480 ret = read_bignum(cp, end, &e, NULL);
485 ret = read_bignum(cp, end, &d, NULL);
490 ret = read_bignum(cp, end, &p, NULL);
495 ret = read_bignum(cp, end, &q, NULL);
499 ret = read_bignum(cp, end, &u, NULL);
503 * OpenSSL uses slightly different parameters than gcrypt. To use these
504 * parameters we need to swap the values of p and q and recompute u.
506 if (gcry_mpi_cmp(p, q) > 0) {
508 gcry_mpi_invm(u, p, q);
510 gret = gcry_sexp_build(&sexp, &erroff, RSA_PRIVKEY_SEXP,
514 PARA_ERROR_LOG("offset %zu: %s\n", erroff,
515 gcry_strerror(gcry_err_code(gret)));
519 key = para_malloc(sizeof(*key));
523 PARA_INFO_LOG("succesfully read %d bit private key\n", ret);
541 /** Public keys start with this header. */
542 #define PUBLIC_KEY_HEADER "-----BEGIN PUBLIC KEY-----"
543 /** Public keys end with this footer. */
544 #define PUBLIC_KEY_FOOTER "-----END PUBLIC KEY-----"
546 static int get_asn_public_key(const char *key_file, struct asymmetric_key **result)
548 gcry_mpi_t n = NULL, e = NULL;
549 unsigned char *blob, *cp, *end;
550 int blob_size, ret, n_size;
554 struct asymmetric_key *key;
556 ret = decode_key(key_file, PUBLIC_KEY_HEADER, PUBLIC_KEY_FOOTER,
561 end = blob + blob_size;
562 ret = find_pubkey_bignum_offset(blob, blob_size);
565 PARA_DEBUG_LOG("decoding public RSA params at offset %d\n", ret);
568 ret = read_bignum(cp, end, &n, &n_size);
573 ret = read_bignum(cp, end, &e, NULL);
577 gret = gcry_sexp_build(&sexp, &erroff, RSA_PUBKEY_SEXP, n, e);
579 PARA_ERROR_LOG("offset %zu: %s\n", erroff,
580 gcry_strerror(gcry_err_code(gret)));
584 key = para_malloc(sizeof(*key));
588 PARA_INFO_LOG("successfully read %u bit asn public key\n", n_size * 8);
599 static int get_ssh_public_key(unsigned char *data, int size, gcry_sexp_t *result)
603 unsigned char *blob = NULL, *p, *end;
604 size_t nr_scanned, erroff, decoded_size;
605 gcry_mpi_t e = NULL, n = NULL;
607 PARA_DEBUG_LOG("decoding %d byte public rsa-ssh key\n", size);
608 if (size > INT_MAX / 4)
609 return -ERRNO_TO_PARA_ERROR(EOVERFLOW);
610 blob = para_malloc(2 * size);
611 ret = uudecode((char *)data, blob, 2 * size);
615 end = blob + decoded_size;
616 dump_buffer("decoded key", blob, decoded_size);
617 ret = check_ssh_key_header(blob, decoded_size);
624 PARA_DEBUG_LOG("scanning modulus and public exponent\n");
625 gret = gcry_mpi_scan(&e, GCRYMPI_FMT_SSH, p, end - p, &nr_scanned);
628 PARA_CRIT_LOG("%s\n", gcry_strerror(gcry_err_code(gret)));
631 PARA_DEBUG_LOG("scanned e (%zu bytes)\n", nr_scanned);
632 // gcry_mpi_aprint(GCRYMPI_FMT_HEX, &buf, NULL, rsa_e);
633 // PARA_CRIT_LOG("e: %s\n", buf);
637 gret = gcry_mpi_scan(&n, GCRYMPI_FMT_SSH, p, end - p, &nr_scanned);
640 PARA_ERROR_LOG("%s\n", gcry_strerror(gcry_err_code(gret)));
643 PARA_DEBUG_LOG("scanned n (%zu bytes)\n", nr_scanned);
644 // gcry_mpi_aprint(GCRYMPI_FMT_HEX, &buf, NULL, rsa_n);
645 // PARA_CRIT_LOG("n: %s\n", buf);
646 gret = gcry_sexp_build(result, &erroff, RSA_PUBKEY_SEXP, n, e);
648 PARA_ERROR_LOG("offset %zu: %s\n", erroff,
649 gcry_strerror(gcry_err_code(gret)));
653 ret = nr_scanned / 32 * 32;
654 PARA_INFO_LOG("successfully read %u bit ssh public key\n", ret * 8);
664 int get_asymmetric_key(const char *key_file, int private,
665 struct asymmetric_key **result)
670 unsigned char *start, *end;
672 struct asymmetric_key *key;
675 return get_private_key(key_file, result);
676 ret = mmap_full_file(key_file, O_RDONLY, &map, &map_size, NULL);
679 ret = is_ssh_rsa_key(map, map_size);
681 ret = para_munmap(map, map_size);
684 return get_asn_public_key(key_file, result);
687 end = map + map_size;
691 ret = get_ssh_public_key(start, end - start, &sexp);
694 key = para_malloc(sizeof(*key));
695 key->num_bytes = ret;
699 ret2 = para_munmap(map, map_size);
700 if (ret >= 0 && ret2 < 0)
705 void free_asymmetric_key(struct asymmetric_key *key)
709 gcry_sexp_release(key->sexp);
713 static int decode_rsa(gcry_sexp_t sexp, int key_size, unsigned char *outbuf,
718 unsigned char oaep_buf[512];
721 if (libgcrypt_has_oaep) {
722 const char *p = gcry_sexp_nth_data(sexp, 1, nbytes);
725 PARA_ERROR_LOG("could not get data from list\n");
728 memcpy(outbuf, p, *nbytes);
731 out_mpi = gcry_sexp_nth_mpi(sexp, 0, GCRYMPI_FMT_USG);
734 gret = gcry_mpi_print(GCRYMPI_FMT_USG, oaep_buf, sizeof(oaep_buf),
737 PARA_ERROR_LOG("mpi_print: %s\n", gcrypt_strerror(gret));
739 goto out_mpi_release;
742 * An oaep-encoded buffer always starts with at least one zero byte.
743 * However, leading zeroes in an mpi are omitted in the output of
744 * gcry_mpi_print() when using the GCRYMPI_FMT_USG format. The
745 * alternative, GCRYMPI_FMT_STD, does not work either because here the
746 * leading zero(es) might also be omitted, depending on the value of
749 * To circumvent this, we shift the oaep buffer to the right. But first
750 * we check that the buffer actually started with a zero byte, i.e. that
751 * nbytes < key_size. Otherwise a decoding error occurred.
753 ret = -E_SEXP_DECRYPT;
754 if (*nbytes >= key_size)
755 goto out_mpi_release;
756 memmove(oaep_buf + key_size - *nbytes, oaep_buf, *nbytes);
757 memset(oaep_buf, 0, key_size - *nbytes);
759 PARA_DEBUG_LOG("decrypted buffer before unpad (%d bytes):\n",
761 dump_buffer("non-unpadded decrypted buffer", oaep_buf, key_size);
762 ret = unpad_oaep(oaep_buf, key_size, outbuf, nbytes);
764 goto out_mpi_release;
765 PARA_DEBUG_LOG("decrypted buffer after unpad (%zu bytes):\n",
767 dump_buffer("unpadded decrypted buffer", outbuf, *nbytes);
770 gcry_mpi_release(out_mpi);
774 int priv_decrypt(const char *key_file, unsigned char *outbuf,
775 unsigned char *inbuf, int inlen)
779 struct asymmetric_key *priv;
780 gcry_mpi_t in_mpi = NULL;
781 gcry_sexp_t in, out, priv_key;
784 PARA_INFO_LOG("decrypting %d byte input\n", inlen);
785 /* key_file -> asymmetric key priv */
786 ret = get_private_key(key_file, &priv);
791 /* asymmetric key priv -> sexp priv_key */
793 priv_key = gcry_sexp_find_token(priv->sexp, "private-key", 0);
797 /* inbuf -> in_mpi */
798 gret = gcry_mpi_scan(&in_mpi, GCRYMPI_FMT_USG, inbuf,
801 PARA_ERROR_LOG("%s\n", gcrypt_strerror(gret));
805 /* in_mpi -> in sexp */
806 gret = gcry_sexp_build(&in, NULL, rsa_decrypt_sexp, in_mpi);
808 PARA_ERROR_LOG("%s\n", gcrypt_strerror(gret));
813 /* rsa decryption: in sexp -> out sexp */
814 gret = gcry_pk_decrypt(&out, in, priv_key);
816 PARA_ERROR_LOG("decrypt: %s\n", gcrypt_strerror(gret));
817 ret = -E_SEXP_DECRYPT;
820 ret = decode_rsa(out, key_size, outbuf, &nbytes);
823 PARA_INFO_LOG("successfully decrypted %zu byte message\n", nbytes);
826 gcry_sexp_release(out);
828 gcry_sexp_release(in);
830 gcry_mpi_release(in_mpi);
832 gcry_sexp_release(priv_key);
834 free_asymmetric_key(priv);
838 int pub_encrypt(struct asymmetric_key *pub, unsigned char *inbuf,
839 unsigned len, unsigned char *outbuf)
842 gcry_sexp_t pub_key, in, out, out_a;
843 gcry_mpi_t out_mpi = NULL;
847 PARA_INFO_LOG("encrypting %u byte input with %d-byte key\n", len, pub->num_bytes);
850 pub_key = gcry_sexp_find_token(pub->sexp, "public-key", 0);
853 if (libgcrypt_has_oaep) {
854 gret = gcry_sexp_build(&in, NULL,
855 "(data(flags oaep)(value %b))", len, inbuf);
857 unsigned char padded_input[256];
858 const size_t pad_size = 256;
859 /* inbuf -> padded inbuf */
860 pad_oaep(inbuf, len, padded_input, pad_size);
861 /* padded inbuf -> in sexp */
862 gret = gcry_sexp_build(&in, NULL,
863 "(data(flags raw)(value %b))", pad_size, padded_input);
866 PARA_ERROR_LOG("%s\n", gcrypt_strerror(gret));
870 /* rsa sexp encryption: in -> out */
871 gret = gcry_pk_encrypt(&out, in, pub_key);
873 PARA_ERROR_LOG("%s\n", gcrypt_strerror(gret));
874 ret = -E_SEXP_ENCRYPT;
877 /* extract a, an MPI with the result of the RSA operation */
879 out_a = gcry_sexp_find_token(out, "a", 0);
882 /* convert sexp out_a -> out_mpi */
883 out_mpi = gcry_sexp_nth_mpi(out_a, 1, GCRYMPI_FMT_USG);
888 gret = gcry_mpi_print(GCRYMPI_FMT_USG, outbuf, 512 /* FIXME */, &nbytes, out_mpi);
890 PARA_ERROR_LOG("%s\n", gcrypt_strerror(gret));
891 ret = -E_SEXP_ENCRYPT;
892 goto out_mpi_release;
894 PARA_INFO_LOG("encrypted buffer is %zu bytes\n", nbytes);
895 dump_buffer("enc buf", outbuf, nbytes);
899 gcry_mpi_release(out_mpi);
901 gcry_sexp_release(out_a);
903 gcry_sexp_release(out);
905 gcry_sexp_release(in);
907 gcry_sexp_release(pub_key);
911 struct stream_cipher {
912 gcry_cipher_hd_t handle;
915 struct stream_cipher *sc_new(const unsigned char *data, int len)
919 struct stream_cipher *sc = para_malloc(sizeof(*sc));
920 gret = gcry_cipher_open(&sc->handle, GCRY_CIPHER_ARCFOUR,
921 GCRY_CIPHER_MODE_STREAM, 0);
923 PARA_ERROR_LOG("%s\n", gcrypt_strerror(gret));
927 gret = gcry_cipher_setkey(sc->handle, data, (size_t)len);
932 void sc_free(struct stream_cipher *sc)
936 gcry_cipher_close(sc->handle);
940 int sc_send_bin_buffer(struct stream_cipher_context *scc, char *buf,
945 unsigned char *tmp = para_malloc(size);
948 gret = gcry_cipher_encrypt(scc->send->handle, tmp, size,
949 (unsigned char *)buf, size);
951 ret = xwrite(scc->fd, (char *)tmp, size);
956 int sc_recv_bin_buffer(struct stream_cipher_context *scc, char *buf,
960 ssize_t ret = recv(scc->fd, buf, size, 0);
963 ret = -ERRNO_TO_PARA_ERROR(errno);
966 /* perform in-place encryption */
967 gret = gcry_cipher_encrypt(scc->recv->handle, (unsigned char *)buf, ret,
973 void sc_crypt(struct stream_cipher *sc, struct iovec *src, struct iovec *dst)
975 gcry_cipher_hd_t handle = sc->handle;
978 /* perform in-place encryption */
980 gret = gcry_cipher_encrypt(handle, src->iov_base, src->iov_len,