-/*
- * Copyright (C) 2011 Andre Noll <maan@tuebingen.mpg.de>
- *
- * Licensed under the GPL v2. For licencing details see COPYING.
- */
+/* Copyright (C) 2011 Andre Noll <maan@tuebingen.mpg.de>, see file COPYING. */
/** \file gcrypt.c Libgrcypt-based encryption/decryption routines. */
}
/*
- * This is called at the beginning of every program that uses libgcrypt. We
- * don't have to initialize any random seed here, but we must initialize the
- * gcrypt library. This task is performed by gcry_check_version() which can
- * also check that the gcrypt library version is at least the minimal required
- * version.
+ * This is called at the beginning of every program that uses libgcrypt. The
+ * call to gcry_check_version() initializes the gcrypt library and checks that
+ * we have at least the minimal required version.
*/
void init_random_seed_or_die(void)
{
- const char *ver, *req_ver;
+ const char *req_ver = "1.5.0";
+ int seed;
- ver = gcry_check_version(NULL);
- req_ver = "1.5.0";
if (!gcry_check_version(req_ver)) {
PARA_EMERG_LOG("fatal: need at least libgcrypt-%s, have: %s\n",
- req_ver, ver);
+ req_ver, gcry_check_version(NULL));
exit(EXIT_FAILURE);
}
+ get_random_bytes_or_die((unsigned char *)&seed, sizeof(seed));
+ srandom(seed);
}
/** S-expression for the public part of an RSA key. */
return c & 0x7f;
}
-static int find_pubkey_bignum_offset(const unsigned char *data, int len)
-{
- const unsigned char *p = data, *end = data + len;
-
- /* the whole thing starts with one sequence */
- if (*p != ASN1_TYPE_SEQUENCE)
- return -E_ASN1_PARSE;
- p++;
- if (p >= end)
- return -E_ASN1_PARSE;
- if (is_short_form(*p))
- p++;
- else
- p += 1 + get_long_form_num_length_bytes(*p);
- if (p >= end)
- return -E_ASN1_PARSE;
- /* another sequence containing the object id, skip it */
- if (*p != ASN1_TYPE_SEQUENCE)
- return -E_ASN1_PARSE;
- p++;
- if (p >= end)
- return -E_ASN1_PARSE;
- if (!is_short_form(*p))
- return -E_ASN1_PARSE;
- p += 1 + get_short_form_length(*p);
- if (p >= end)
- return -E_ASN1_PARSE;
- /* all numbers are wrapped in a bit string object that follows */
- if (*p != ASN1_TYPE_BIT_STRING)
- return -E_ASN1_PARSE;
- p++;
- if (p >= end)
- return -E_ASN1_PARSE;
- if (is_short_form(*p))
- p++;
- else
- p += 1 + get_long_form_num_length_bytes(*p);
- p++; /* skip number of unused bits in the bit string */
- if (p >= end)
- return -E_ASN1_PARSE;
-
- /* next, we have a sequence of two integers (n and e) */
- if (*p != ASN1_TYPE_SEQUENCE)
- return -E_ASN1_PARSE;
- p++;
- if (p >= end)
- return -E_ASN1_PARSE;
- if (is_short_form(*p))
- p++;
- else
- p += 1 + get_long_form_num_length_bytes(*p);
- if (p >= end)
- return -E_ASN1_PARSE;
- if (*p != ASN1_TYPE_INTEGER)
- return -E_ASN1_PARSE;
- return p - data;
-}
-
/*
* Returns: Number of bytes scanned. This may differ from the value returned via
* bn_bytes because the latter does not include the ASN.1 prefix and a leading
gcry_sexp_t sexp;
struct asymmetric_key *key;
+ *result = NULL;
ret = decode_key(key_file, PRIVATE_KEY_HEADER, PRIVATE_KEY_FOOTER,
&blob);
if (ret < 0)
return ret;
}
-/** Public keys start with this header. */
-#define PUBLIC_KEY_HEADER "-----BEGIN PUBLIC KEY-----"
-/** Public keys end with this footer. */
-#define PUBLIC_KEY_FOOTER "-----END PUBLIC KEY-----"
-
-static int get_asn_public_key(const char *key_file, struct asymmetric_key **result)
+int get_public_key(const char *key_file, struct asymmetric_key **result)
{
- gcry_mpi_t n = NULL, e = NULL;
- unsigned char *blob, *cp, *end;
- int blob_size, ret, n_size;
+ unsigned char *blob, *p, *end;
+ int ret;
gcry_error_t gret;
- size_t erroff;
+ size_t nr_scanned, erroff, decoded_size;
+ gcry_mpi_t e, n;
gcry_sexp_t sexp;
struct asymmetric_key *key;
- ret = decode_key(key_file, PUBLIC_KEY_HEADER, PUBLIC_KEY_FOOTER,
- &blob);
+ ret = decode_ssh_key(key_file, &blob, &decoded_size);
if (ret < 0)
return ret;
- blob_size = ret;
- end = blob + blob_size;
- ret = find_pubkey_bignum_offset(blob, blob_size);
- if (ret < 0)
- goto free_blob;
- PARA_DEBUG_LOG("decoding public RSA params at offset %d\n", ret);
- cp = blob + ret;
-
- ret = read_bignum(cp, end, &n, &n_size);
- if (ret < 0)
- goto free_blob;
- cp += ret;
-
- ret = read_bignum(cp, end, &e, NULL);
- if (ret < 0)
- goto release_n;
-
- gret = gcry_sexp_build(&sexp, &erroff, RSA_PUBKEY_SEXP, n, e);
- if (gret) {
- PARA_ERROR_LOG("offset %zu: %s\n", erroff,
- gcry_strerror(gcry_err_code(gret)));
- ret = -E_SEXP_BUILD;
- goto release_e;
- }
- key = para_malloc(sizeof(*key));
- key->sexp = sexp;
- key->num_bytes = n_size;
- *result = key;
- ret = n_size;
- PARA_INFO_LOG("successfully read %d bit asn public key\n", n_size * 8);
-
-release_e:
- gcry_mpi_release(e);
-release_n:
- gcry_mpi_release(n);
-free_blob:
- free(blob);
- return ret;
-}
-
-static int get_ssh_public_key(unsigned char *data, int size, gcry_sexp_t *result)
-{
- int ret;
- gcry_error_t gret;
- unsigned char *blob = NULL, *p, *end;
- size_t nr_scanned, erroff, decoded_size;
- gcry_mpi_t e = NULL, n = NULL;
-
- PARA_DEBUG_LOG("decoding %d byte public rsa-ssh key\n", size);
- ret = uudecode((char *)data, size, (char **)&blob, &decoded_size);
- if (ret < 0)
- goto free_blob;
- end = blob + decoded_size;
- dump_buffer("decoded key", blob, decoded_size);
- ret = check_ssh_key_header(blob, decoded_size);
- if (ret < 0)
- goto free_blob;
p = blob + ret;
- ret = -E_SSH_PARSE;
- if (p >= end)
- goto free_blob;
+ end = blob + decoded_size;
PARA_DEBUG_LOG("scanning modulus and public exponent\n");
gret = gcry_mpi_scan(&e, GCRYMPI_FMT_SSH, p, end - p, &nr_scanned);
if (gret) {
goto free_blob;
}
PARA_DEBUG_LOG("scanned e (%zu bytes)\n", nr_scanned);
-// gcry_mpi_aprint(GCRYMPI_FMT_HEX, &buf, NULL, rsa_e);
-// PARA_CRIT_LOG("e: %s\n", buf);
p += nr_scanned;
if (p >= end)
goto release_e;
goto release_e;
}
PARA_DEBUG_LOG("scanned n (%zu bytes)\n", nr_scanned);
-// gcry_mpi_aprint(GCRYMPI_FMT_HEX, &buf, NULL, rsa_n);
-// PARA_CRIT_LOG("n: %s\n", buf);
- gret = gcry_sexp_build(result, &erroff, RSA_PUBKEY_SEXP, n, e);
+ gret = gcry_sexp_build(&sexp, &erroff, RSA_PUBKEY_SEXP, n, e);
if (gret) {
PARA_ERROR_LOG("offset %zu: %s\n", erroff,
gcry_strerror(gcry_err_code(gret)));
}
ret = nr_scanned / 32 * 32;
PARA_INFO_LOG("successfully read %d bit ssh public key\n", ret * 8);
+ key = para_malloc(sizeof(*key));
+ key->num_bytes = ret;
+ key->sexp = sexp;
+ *result = key;
release_n:
gcry_mpi_release(n);
release_e:
return ret;
}
-int get_asymmetric_key(const char *key_file, int private,
- struct asymmetric_key **result)
-{
- int ret, ret2;
- void *map;
- size_t map_size;
- unsigned char *start, *end;
- gcry_sexp_t sexp;
- struct asymmetric_key *key;
-
- if (private)
- return get_private_key(key_file, result);
- ret = mmap_full_file(key_file, O_RDONLY, &map, &map_size, NULL);
- if (ret < 0)
- return ret;
- ret = is_ssh_rsa_key(map, map_size);
- if (!ret) {
- ret = para_munmap(map, map_size);
- if (ret < 0)
- return ret;
- return get_asn_public_key(key_file, result);
- }
- start = map + ret;
- end = map + map_size;
- ret = -E_SSH_PARSE;
- if (start >= end)
- goto unmap;
- ret = get_ssh_public_key(start, end - start, &sexp);
- if (ret < 0)
- goto unmap;
- key = para_malloc(sizeof(*key));
- key->num_bytes = ret;
- key->sexp = sexp;
- *result = key;
-unmap:
- ret2 = para_munmap(map, map_size);
- if (ret >= 0 && ret2 < 0)
- ret = ret2;
- return ret;
-}
-
-void free_asymmetric_key(struct asymmetric_key *key)
+void free_public_key(struct asymmetric_key *key)
{
if (!key)
return;
{
const char *p = gcry_sexp_nth_data(sexp, 1, nbytes);
- if (!p) {
- PARA_ERROR_LOG("could not get data from list\n");
- return -E_OEAP;
- }
+ if (!p)
+ return -E_RSA_DECODE;
memcpy(outbuf, p, *nbytes);
return 1;
}
gcry_sexp_t in, out, priv_key;
size_t nbytes;
- ret = check_key_file(key_file, true);
+ ret = check_private_key_file(key_file);
if (ret < 0)
return ret;
PARA_INFO_LOG("decrypting %d byte input\n", inlen);
key_release:
gcry_sexp_release(priv_key);
free_key:
- free_asymmetric_key(priv);
+ gcry_sexp_release(priv->sexp);
+ free(priv);
return ret;
}
gcry_cipher_hd_t handle;
};
-struct stream_cipher *sc_new(const unsigned char *data, int len,
- bool use_aes)
+struct stream_cipher *sc_new(const unsigned char *data, int len)
{
gcry_error_t gret;
struct stream_cipher *sc = para_malloc(sizeof(*sc));
- if (use_aes) {
- assert(len >= 2 * AES_CRT128_BLOCK_SIZE);
- gret = gcry_cipher_open(&sc->handle, GCRY_CIPHER_AES128,
- GCRY_CIPHER_MODE_CTR, 0);
- assert(gret == 0);
- gret = gcry_cipher_setkey(sc->handle, data,
- AES_CRT128_BLOCK_SIZE);
- assert(gret == 0);
- gret = gcry_cipher_setctr(sc->handle,
- data + AES_CRT128_BLOCK_SIZE, AES_CRT128_BLOCK_SIZE);
- assert(gret == 0);
- return sc;
- }
- gret = gcry_cipher_open(&sc->handle, GCRY_CIPHER_ARCFOUR,
- GCRY_CIPHER_MODE_STREAM, 0);
- if (gret) {
- PARA_ERROR_LOG("%s\n", gcrypt_strerror(gret));
- free(sc);
- return NULL;
- }
- gret = gcry_cipher_setkey(sc->handle, data, (size_t)len);
+ assert(len >= 2 * AES_CRT128_BLOCK_SIZE);
+ gret = gcry_cipher_open(&sc->handle, GCRY_CIPHER_AES128,
+ GCRY_CIPHER_MODE_CTR, 0);
+ assert(gret == 0);
+ gret = gcry_cipher_setkey(sc->handle, data,
+ AES_CRT128_BLOCK_SIZE);
+ assert(gret == 0);
+ gret = gcry_cipher_setctr(sc->handle,
+ data + AES_CRT128_BLOCK_SIZE, AES_CRT128_BLOCK_SIZE);
assert(gret == 0);
return sc;
}
projects / paraslash.git / blobdiff