-/*
- * 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. */
#include "crypt.h"
#include "crypt_backend.h"
#include "fd.h"
+#include "base64.h"
//#define GCRYPT_DEBUG 1
-static bool libgcrypt_has_oaep;
-static const char *rsa_decrypt_sexp;
-
#ifdef GCRYPT_DEBUG
static void dump_buffer(const char *msg, unsigned char *buf, int len)
{
gcry_md_close(handle);
}
+void hash2_function(const char *data, unsigned long len, unsigned char *hash)
+{
+ gcry_error_t gret;
+ gcry_md_hd_t handle;
+ unsigned char *md;
+
+ gret = gcry_md_open(&handle, GCRY_MD_SHA256, 0);
+ assert(gret == 0);
+ gcry_md_write(handle, data, (size_t)len);
+ gcry_md_final(handle);
+ md = gcry_md_read(handle, GCRY_MD_SHA256);
+ assert(md);
+ memcpy(hash, md, HASH2_SIZE);
+ gcry_md_close(handle);
+}
+
void get_random_bytes_or_die(unsigned char *buf, int num)
{
gcry_randomize(buf, (size_t)num, GCRY_STRONG_RANDOM);
}
/*
- * 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 function also tells us whether we have to use our own OAEP
- * padding code.
+ * 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)
+void crypt_init(void)
{
- const char *ver, *req_ver;
+ const char *req_ver = "1.5.0";
+ int seed;
- ver = gcry_check_version(NULL);
- req_ver = "1.4.0";
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);
}
- req_ver = "1.5.0";
- if (gcry_check_version(req_ver)) {
- libgcrypt_has_oaep = true;
- rsa_decrypt_sexp = "(enc-val(flags oaep)(rsa(a %m)))";
- } else {
- libgcrypt_has_oaep = false;
- rsa_decrypt_sexp = "(enc-val(rsa(a %m)))";
- }
-}
-/** S-expression for the public part of an RSA key. */
-#define RSA_PUBKEY_SEXP "(public-key (rsa (n %m) (e %m)))"
-/** S-expression for a private RSA key. */
-#define RSA_PRIVKEY_SEXP "(private-key (rsa (n %m) (e %m) (d %m) (p %m) (q %m) (u %m)))"
+ /*
+ * Allocate a pool of secure memory. This also drops privileges where
+ * needed.
+ */
+ gcry_control(GCRYCTL_INIT_SECMEM, 65536, 0);
-/* rfc 3447, appendix B.2 */
-static void mgf1(unsigned char *seed, size_t seed_len, unsigned result_len,
- unsigned char *result)
-{
- gcry_error_t gret;
- gcry_md_hd_t handle;
- size_t n;
- unsigned char *md;
- unsigned char octet_string[4], *rp = result, *end = rp + result_len;
+ /* Tell Libgcrypt that initialization has completed. */
+ gcry_control(GCRYCTL_INITIALIZATION_FINISHED, 0);
- assert(result_len / HASH_SIZE < 1ULL << 31);
- gret = gcry_md_open(&handle, GCRY_MD_SHA1, 0);
- assert(gret == 0);
- for (n = 0; rp < end; n++) {
- gcry_md_write(handle, seed, seed_len);
- octet_string[0] = (unsigned char)((n >> 24) & 255);
- octet_string[1] = (unsigned char)((n >> 16) & 255);
- octet_string[2] = (unsigned char)((n >> 8)) & 255;
- octet_string[3] = (unsigned char)(n & 255);
- gcry_md_write(handle, octet_string, 4);
- gcry_md_final(handle);
- md = gcry_md_read(handle, GCRY_MD_SHA1);
- memcpy(rp, md, PARA_MIN(HASH_SIZE, (int)(end - rp)));
- rp += HASH_SIZE;
- gcry_md_reset(handle);
- }
- gcry_md_close(handle);
+ get_random_bytes_or_die((unsigned char *)&seed, sizeof(seed));
+ srandom(seed);
}
-/** The sha1 hash of an empty file. */
-static const unsigned char empty_hash[HASH_SIZE] =
- "\xda" "\x39" "\xa3" "\xee" "\x5e"
- "\x6b" "\x4b" "\x0d" "\x32" "\x55"
- "\xbf" "\xef" "\x95" "\x60" "\x18"
- "\x90" "\xaf" "\xd8" "\x07" "\x09";
-
-/* rfc3447, section 7.1.1 */
-static void pad_oaep(unsigned char *in, size_t in_len, unsigned char *out,
- size_t out_len)
+void crypt_shutdown(void)
{
- size_t ps_len = out_len - in_len - 2 * HASH_SIZE - 2;
- size_t n, mask_len = out_len - HASH_SIZE - 1;
- unsigned char *seed = out + 1, *db = seed + HASH_SIZE,
- *ps = db + HASH_SIZE, *one = ps + ps_len;
- unsigned char *db_mask, seed_mask[HASH_SIZE];
-
- assert(in_len <= out_len - 2 - 2 * HASH_SIZE);
- assert(out_len > 2 * HASH_SIZE + 2);
- PARA_DEBUG_LOG("padding %zu byte input -> %zu byte output\n",
- in_len, out_len);
- dump_buffer("unpadded buffer", in, in_len);
-
- out[0] = '\0';
- get_random_bytes_or_die(seed, HASH_SIZE);
- memcpy(db, empty_hash, HASH_SIZE);
- memset(ps, 0, ps_len);
- *one = 0x01;
- memcpy(one + 1, in, in_len);
- db_mask = para_malloc(mask_len);
- mgf1(seed, HASH_SIZE, mask_len, db_mask);
- for (n = 0; n < mask_len; n++)
- db[n] ^= db_mask[n];
- mgf1(db, mask_len, HASH_SIZE, seed_mask);
- for (n = 0; n < HASH_SIZE; n++)
- seed[n] ^= seed_mask[n];
- free(db_mask);
- dump_buffer("padded buffer", out, out_len);
+ /*
+ * WK does not see a way to apply a patch for the sake of Valgrind, so
+ * as of 2018 libgrypt has no deinitialization routine to free the
+ * resources on exit.
+ */
}
-/* rfc 3447, section 7.1.2 */
-static int unpad_oaep(unsigned char *in, size_t in_len, unsigned char *out,
- size_t *out_len)
-{
- unsigned char *masked_seed = in + 1;
- unsigned char *db = in + 1 + HASH_SIZE;
- unsigned char seed[HASH_SIZE], seed_mask[HASH_SIZE];
- unsigned char *db_mask, *p;
- size_t n, mask_len = in_len - HASH_SIZE - 1;
-
- mgf1(db, mask_len, HASH_SIZE, seed_mask);
- for (n = 0; n < HASH_SIZE; n++)
- seed[n] = masked_seed[n] ^ seed_mask[n];
- db_mask = para_malloc(mask_len);
- mgf1(seed, HASH_SIZE, mask_len, db_mask);
- for (n = 0; n < mask_len; n++)
- db[n] ^= db_mask[n];
- free(db_mask);
- if (memcmp(db, empty_hash, HASH_SIZE))
- return -E_OEAP;
- for (p = db + HASH_SIZE; p < in + in_len - 1; p++)
- if (*p != '\0')
- break;
- if (p >= in + in_len - 1)
- return -E_OEAP;
- p++;
- *out_len = in + in_len - p;
- memcpy(out, p, *out_len);
- return 1;
-}
+/** S-expression for the public part of an RSA key. */
+#define RSA_PUBKEY_SEXP "(public-key (rsa (n %m) (e %m)))"
+/** S-expression for a private RSA key. */
+#define RSA_PRIVKEY_SEXP "(private-key (rsa (n %m) (e %m) (d %m) (p %m) (q %m) (u %m)))"
+/** S-expression for decryption. */
+#define RSA_DECRYPT_SEXP "(enc-val(flags oaep)(rsa(a %m)))"
struct asymmetric_key {
gcry_sexp_t sexp;
return gcry_strerror(gcry_err_code(gret));
}
-static int decode_key(const char *key_file, const char *header_str,
- const char *footer_str, unsigned char **result)
-{
- int ret, ret2, i, j;
- void *map;
- size_t map_size, key_size, blob_size;
- unsigned char *blob = NULL;
- char *begin, *footer, *key;
-
- ret = mmap_full_file(key_file, O_RDONLY, &map, &map_size, NULL);
- if (ret < 0)
- goto out;
- ret = -E_KEY_MARKER;
- if (strncmp(map, header_str, strlen(header_str)))
- goto unmap;
- footer = strstr(map, footer_str);
- ret = -E_KEY_MARKER;
- if (!footer)
- goto unmap;
- begin = map + strlen(header_str);
- /* skip whitespace at the beginning */
- for (; begin < footer; begin++) {
- if (para_isspace(*begin))
- continue;
- break;
- }
- ret = -E_KEY_MARKER;
- if (begin >= footer)
- goto unmap;
-
- key_size = footer - begin;
- key = para_malloc(key_size + 1);
- for (i = 0, j = 0; begin + i < footer; i++) {
- if (para_isspace(begin[i]))
- continue;
- key[j++] = begin[i];
- }
- key[j] = '\0';
- blob_size = key_size * 2;
- blob = para_malloc(blob_size);
- ret = base64_decode(key, blob, blob_size);
- free(key);
- if (ret < 0)
- goto free_unmap;
- goto unmap;
-free_unmap:
- free(blob);
- blob = NULL;
-unmap:
- ret2 = para_munmap(map, map_size);
- if (ret >= 0 && ret2 < 0)
- ret = ret2;
- if (ret < 0) {
- free(blob);
- blob = NULL;
- }
-out:
- *result = blob;
- return ret;
-}
-
/** ASN Types and their code. */
enum asn1_types {
/** The next object is an integer. */
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
- * zero is not considered as an additional byte for bn_bytes.
+ * bitsp because the latter does not include the ASN.1 prefix and a leading
+ * zero is not considered as an additional byte for the number of bits.
*/
-static int read_bignum(unsigned char *start, unsigned char *end, gcry_mpi_t *bn,
- int *bn_bytes)
+static int read_pem_bignum(unsigned char *start, unsigned char *end, gcry_mpi_t *bn,
+ unsigned *bitsp)
{
int i, bn_size;
gcry_error_t gret;
for (i = 0; i < num_bytes; i++, cp++)
bn_size = (bn_size << 8) + *cp;
}
- PARA_DEBUG_LOG("bn_size %d (0x%x)\n", bn_size, bn_size);
+ PARA_DEBUG_LOG("bn_size %d (0x%x)\n", bn_size, (unsigned)bn_size);
gret = gcry_mpi_scan(bn, GCRYMPI_FMT_STD, cp, bn_size, NULL);
if (gret) {
- PARA_ERROR_LOG("%s while scanning n\n",
+ PARA_ERROR_LOG("gcry_mpi_scan: %s\n",
gcry_strerror(gcry_err_code(gret)));
return-E_MPI_SCAN;
}
cp++;
bn_size--;
}
- if (bn_bytes)
- *bn_bytes = bn_size;
+ if (bitsp)
+ *bitsp = bn_size * 8;
cp += bn_size;
// unsigned char *buf;
// gcry_mpi_aprint(GCRYMPI_FMT_HEX, &buf, NULL, *bn);
return cp - start;
}
-static int find_privkey_bignum_offset(const unsigned char *data, int len)
+struct rsa_params {
+ gcry_mpi_t n, e, d, p, q, u;
+};
+
+static int read_pem_rsa_params(unsigned char *start, unsigned char *end,
+ struct rsa_params *p)
+{
+ unsigned char *cp = start;
+ unsigned bits;
+ int ret;
+
+ ret = read_pem_bignum(cp, end, &p->n, &bits);
+ if (ret < 0)
+ return ret;
+ cp += ret;
+ ret = read_pem_bignum(cp, end, &p->e, NULL);
+ if (ret < 0)
+ goto release_n;
+ cp += ret;
+ ret = read_pem_bignum(cp, end, &p->d, NULL);
+ if (ret < 0)
+ goto release_e;
+ cp += ret;
+ ret = read_pem_bignum(cp, end, &p->p, NULL);
+ if (ret < 0)
+ goto release_d;
+ cp += ret;
+ ret = read_pem_bignum(cp, end, &p->q, NULL);
+ if (ret < 0)
+ goto release_p;
+ cp += ret;
+ ret = read_pem_bignum(cp, end, &p->u, NULL);
+ if (ret < 0)
+ goto release_q;
+ return bits;
+release_q:
+ gcry_mpi_release(p->q);
+release_p:
+ gcry_mpi_release(p->p);
+release_d:
+ gcry_mpi_release(p->d);
+release_e:
+ gcry_mpi_release(p->e);
+release_n:
+ gcry_mpi_release(p->n);
+ return ret;
+}
+
+static int find_pem_bignum_offset(const unsigned char *data, int len)
{
const unsigned char *p = data, *end = data + len;
return p - data;
}
-/** Private keys start with this header. */
-#define PRIVATE_KEY_HEADER "-----BEGIN RSA PRIVATE KEY-----"
-/** Private keys end with this footer. */
-#define PRIVATE_KEY_FOOTER "-----END RSA PRIVATE KEY-----"
-
-static int get_private_key(const char *key_file, struct asymmetric_key **result)
+static int read_openssh_bignum(unsigned char *start, unsigned char *end,
+ gcry_mpi_t *bn, unsigned *bitsp)
{
- gcry_mpi_t n = NULL, e = NULL, d = NULL, p = NULL, q = NULL,
- u = NULL;
- unsigned char *blob, *cp, *end;
- int blob_size, ret, n_size;
gcry_error_t gret;
- size_t erroff;
- gcry_sexp_t sexp;
- struct asymmetric_key *key;
+ size_t nscanned;
+ unsigned bits;
- ret = decode_key(key_file, PRIVATE_KEY_HEADER, PRIVATE_KEY_FOOTER,
- &blob);
- if (ret < 0)
- return ret;
- blob_size = ret;
- end = blob + blob_size;
- ret = find_privkey_bignum_offset(blob, blob_size);
- if (ret < 0)
- goto free_blob;
- PARA_INFO_LOG("reading RSA params at offset %d\n", ret);
- cp = blob + ret;
+ gret = gcry_mpi_scan(bn, GCRYMPI_FMT_SSH, start, end - start, &nscanned);
+ if (gret) {
+ PARA_ERROR_LOG("gcry_mpi_scan: %s\n",
+ gcry_strerror(gcry_err_code(gret)));
+ return -E_MPI_SCAN;
+ }
+ bits = (nscanned - 4 - (start[4] == '\0')) * 8;
+ if (bitsp)
+ *bitsp = bits;
+ PARA_DEBUG_LOG("scanned %u-bit bignum\n", bits);
+ return nscanned;
+}
+
+static int read_openssh_rsa_params(unsigned char *start, unsigned char *end,
+ struct rsa_params *p)
+{
+ unsigned char *cp = start;
+ unsigned bits;
+ int ret;
- ret = read_bignum(cp, end, &n, &n_size);
+ ret = read_openssh_bignum(cp, end, &p->n, &bits);
if (ret < 0)
- goto free_blob;
+ return ret;
cp += ret;
-
- ret = read_bignum(cp, end, &e, NULL);
+ ret = read_openssh_bignum(cp, end, &p->e, NULL);
if (ret < 0)
goto release_n;
cp += ret;
-
- ret = read_bignum(cp, end, &d, NULL);
+ ret = read_openssh_bignum(cp, end, &p->d, NULL);
if (ret < 0)
goto release_e;
cp += ret;
-
- ret = read_bignum(cp, end, &p, NULL);
+ ret = read_openssh_bignum(cp, end, &p->u, NULL);
if (ret < 0)
goto release_d;
cp += ret;
-
- ret = read_bignum(cp, end, &q, NULL);
+ ret = read_openssh_bignum(cp, end, &p->p, NULL);
if (ret < 0)
- goto release_p;
+ goto release_u;
cp += ret;
- ret = read_bignum(cp, end, &u, NULL);
+ ret = read_openssh_bignum(cp, end, &p->q, NULL);
if (ret < 0)
- goto release_q;
- /*
- * OpenSSL uses slightly different parameters than gcrypt. To use these
- * parameters we need to swap the values of p and q and recompute u.
- */
- if (gcry_mpi_cmp(p, q) > 0) {
- gcry_mpi_swap(p, q);
- gcry_mpi_invm(u, p, q);
- }
- gret = gcry_sexp_build(&sexp, &erroff, RSA_PRIVKEY_SEXP,
- n, e, d, p, q, u);
-
- if (gret) {
- PARA_ERROR_LOG("offset %zu: %s\n", erroff,
- gcry_strerror(gcry_err_code(gret)));
- ret = -E_SEXP_BUILD;
- goto release_u;
- }
- key = para_malloc(sizeof(*key));
- key->sexp = sexp;
- *result = key;
- ret = n_size * 8;
- PARA_INFO_LOG("succesfully read %d bit private key\n", ret);
-release_u:
- gcry_mpi_release(u);
-release_q:
- gcry_mpi_release(q);
+ goto release_p;
+ return bits;
release_p:
- gcry_mpi_release(p);
+ gcry_mpi_release(p->p);
+release_u:
+ gcry_mpi_release(p->u);
release_d:
- gcry_mpi_release(d);
+ gcry_mpi_release(p->d);
release_e:
- gcry_mpi_release(e);
+ gcry_mpi_release(p->e);
release_n:
- gcry_mpi_release(n);
-free_blob:
- free(blob);
+ gcry_mpi_release(p->n);
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)
+static int get_private_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;
+ struct rsa_params params;
+ unsigned char *blob, *end;
+ unsigned bits;
+ int ret, key_type;
gcry_error_t gret;
- size_t erroff;
+ size_t erroff, blob_size;
gcry_sexp_t sexp;
struct asymmetric_key *key;
- ret = decode_key(key_file, PUBLIC_KEY_HEADER, PUBLIC_KEY_FOOTER,
- &blob);
+ *result = NULL;
+ ret = decode_private_key(key_file, &blob, &blob_size);
if (ret < 0)
return ret;
- blob_size = ret;
+ key_type = ret;
end = blob + blob_size;
- ret = find_pubkey_bignum_offset(blob, blob_size);
+ if (key_type == PKT_PEM)
+ ret = find_pem_bignum_offset(blob, blob_size);
+ else
+ ret = find_openssh_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);
+ PARA_INFO_LOG("reading RSA params at offset %d\n", ret);
+ if (key_type == PKT_PEM)
+ ret = read_pem_rsa_params(blob + ret, end, ¶ms);
+ else
+ ret = read_openssh_rsa_params(blob + ret, end, ¶ms);
if (ret < 0)
goto free_blob;
- cp += ret;
-
- ret = read_bignum(cp, end, &e, NULL);
- if (ret < 0)
- goto release_n;
+ bits = ret;
+ /*
+ * OpenSSL uses slightly different parameters than gcrypt. To use these
+ * parameters we need to swap the values of p and q and recompute u.
+ */
+ if (gcry_mpi_cmp(params.p, params.q) > 0) {
+ gcry_mpi_swap(params.p, params.q);
+ gcry_mpi_invm(params.u, params.p, params.q);
+ }
+ gret = gcry_sexp_build(&sexp, &erroff, RSA_PRIVKEY_SEXP, params.n,
+ params.e, params.d, params.p, params.q, params.u);
- 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;
+ goto free_params;
}
- key = para_malloc(sizeof(*key));
+ key = alloc(sizeof(*key));
key->sexp = sexp;
- key->num_bytes = n_size;
*result = key;
- ret = n_size;
- PARA_INFO_LOG("successfully read %u bit asn public key\n", n_size * 8);
+ ret = bits;
+ PARA_INFO_LOG("succesfully read %d bit private key\n", ret);
+free_params:
+ gcry_mpi_release(params.n);
+ gcry_mpi_release(params.e);
+ gcry_mpi_release(params.d);
+ gcry_mpi_release(params.u);
+ gcry_mpi_release(params.p);
+ gcry_mpi_release(params.q);
-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 apc_get_pubkey(const char *key_file, struct asymmetric_key **result)
{
+ unsigned char *blob, *p, *end;
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);
- if (size > INT_MAX / 4)
- return -ERRNO_TO_PARA_ERROR(EOVERFLOW);
- blob = para_malloc(2 * size);
- ret = uudecode((char *)data, blob, 2 * size);
- if (ret < 0)
- goto free_blob;
- decoded_size = ret;
- end = blob + decoded_size;
- dump_buffer("decoded key", blob, decoded_size);
- ret = check_ssh_key_header(blob, decoded_size);
+ size_t erroff, decoded_size;
+ gcry_mpi_t e, n;
+ gcry_sexp_t sexp;
+ struct asymmetric_key *key;
+ unsigned bits;
+
+ ret = decode_public_key(key_file, &blob, &decoded_size);
if (ret < 0)
- goto free_blob;
+ return ret;
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) {
- ret = -E_MPI_SCAN;
- PARA_CRIT_LOG("%s\n", gcry_strerror(gcry_err_code(gret)));
+ ret = read_openssh_bignum(p, end, &e, NULL);
+ if (ret < 0)
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;
- gret = gcry_mpi_scan(&n, GCRYMPI_FMT_SSH, p, end - p, &nr_scanned);
- if (gret) {
- ret = -E_MPI_SCAN;
- PARA_ERROR_LOG("%s\n", gcry_strerror(gcry_err_code(gret)));
+ p += ret;
+ ret = read_openssh_bignum(p, end, &n, &bits);
+ if (ret < 0)
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 = -E_SEXP_BUILD;
goto release_n;
}
- ret = nr_scanned / 32 * 32;
- PARA_INFO_LOG("successfully read %u bit ssh public key\n", ret * 8);
+ PARA_INFO_LOG("successfully read %u bit ssh public key\n", bits);
+ key = alloc(sizeof(*key));
+ key->num_bytes = ret;
+ key->sexp = sexp;
+ *result = key;
+ ret = bits;
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 apc_free_pubkey(struct asymmetric_key *key)
{
if (!key)
return;
free(key);
}
-static int decode_rsa(gcry_sexp_t sexp, int key_size, unsigned char *outbuf,
- size_t *nbytes)
+static int decode_rsa(gcry_sexp_t sexp, unsigned char *outbuf, size_t *nbytes)
{
- int ret;
- gcry_error_t gret;
- unsigned char oaep_buf[512];
- gcry_mpi_t out_mpi;
-
- if (libgcrypt_has_oaep) {
- 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;
- }
- memcpy(outbuf, p, *nbytes);
- return 1;
- }
- out_mpi = gcry_sexp_nth_mpi(sexp, 0, GCRYMPI_FMT_USG);
- if (!out_mpi)
- return -E_SEXP_FIND;
- gret = gcry_mpi_print(GCRYMPI_FMT_USG, oaep_buf, sizeof(oaep_buf),
- nbytes, out_mpi);
- if (gret) {
- PARA_ERROR_LOG("mpi_print: %s\n", gcrypt_strerror(gret));
- ret = -E_MPI_PRINT;
- goto out_mpi_release;
- }
- /*
- * An oaep-encoded buffer always starts with at least one zero byte.
- * However, leading zeroes in an mpi are omitted in the output of
- * gcry_mpi_print() when using the GCRYMPI_FMT_USG format. The
- * alternative, GCRYMPI_FMT_STD, does not work either because here the
- * leading zero(es) might also be omitted, depending on the value of
- * the second byte.
- *
- * To circumvent this, we shift the oaep buffer to the right. But first
- * we check that the buffer actually started with a zero byte, i.e. that
- * nbytes < key_size. Otherwise a decoding error occurred.
- */
- ret = -E_SEXP_DECRYPT;
- if (*nbytes >= key_size)
- goto out_mpi_release;
- memmove(oaep_buf + key_size - *nbytes, oaep_buf, *nbytes);
- memset(oaep_buf, 0, key_size - *nbytes);
+ const char *p = gcry_sexp_nth_data(sexp, 1, nbytes);
- PARA_DEBUG_LOG("decrypted buffer before unpad (%d bytes):\n",
- key_size);
- dump_buffer("non-unpadded decrypted buffer", oaep_buf, key_size);
- ret = unpad_oaep(oaep_buf, key_size, outbuf, nbytes);
- if (ret < 0)
- goto out_mpi_release;
- PARA_DEBUG_LOG("decrypted buffer after unpad (%zu bytes):\n",
- *nbytes);
- dump_buffer("unpadded decrypted buffer", outbuf, *nbytes);
- ret = 1;
-out_mpi_release:
- gcry_mpi_release(out_mpi);
- return ret;
+ if (!p)
+ return -E_RSA_DECODE;
+ memcpy(outbuf, p, *nbytes);
+ return 1;
}
-int priv_decrypt(const char *key_file, unsigned char *outbuf,
+int apc_priv_decrypt(const char *key_file, unsigned char *outbuf,
unsigned char *inbuf, int inlen)
{
gcry_error_t gret;
- int ret, key_size;
+ int ret;
struct asymmetric_key *priv;
gcry_mpi_t in_mpi = NULL;
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);
ret = get_private_key(key_file, &priv);
if (ret < 0)
return ret;
- key_size = ret / 8;
/* asymmetric key priv -> sexp priv_key */
ret = -E_SEXP_FIND;
goto key_release;
}
/* in_mpi -> in sexp */
- gret = gcry_sexp_build(&in, NULL, rsa_decrypt_sexp, in_mpi);
+ gret = gcry_sexp_build(&in, NULL, RSA_DECRYPT_SEXP, in_mpi);
if (gret) {
PARA_ERROR_LOG("%s\n", gcrypt_strerror(gret));
ret = -E_SEXP_BUILD;
ret = -E_SEXP_DECRYPT;
goto in_release;
}
- ret = decode_rsa(out, key_size, outbuf, &nbytes);
+ ret = decode_rsa(out, outbuf, &nbytes);
if (ret < 0)
goto out_release;
PARA_INFO_LOG("successfully decrypted %zu byte message\n", nbytes);
key_release:
gcry_sexp_release(priv_key);
free_key:
- free_asymmetric_key(priv);
+ gcry_sexp_release(priv->sexp);
+ free(priv);
return ret;
}
-int pub_encrypt(struct asymmetric_key *pub, unsigned char *inbuf,
+int apc_pub_encrypt(struct asymmetric_key *pub, unsigned char *inbuf,
unsigned len, unsigned char *outbuf)
{
gcry_error_t gret;
pub_key = gcry_sexp_find_token(pub->sexp, "public-key", 0);
if (!pub_key)
return -E_SEXP_FIND;
- if (libgcrypt_has_oaep) {
- gret = gcry_sexp_build(&in, NULL,
- "(data(flags oaep)(value %b))", len, inbuf);
- } else {
- unsigned char padded_input[256];
- const size_t pad_size = 256;
- /* inbuf -> padded inbuf */
- pad_oaep(inbuf, len, padded_input, pad_size);
- /* padded inbuf -> in sexp */
- gret = gcry_sexp_build(&in, NULL,
- "(data(flags raw)(value %b))", pad_size, padded_input);
- }
+ gret = gcry_sexp_build(&in, NULL, "(data(flags oaep)(value %b))", len, inbuf);
if (gret) {
PARA_ERROR_LOG("%s\n", gcrypt_strerror(gret));
ret = -E_SEXP_BUILD;
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);
+ struct stream_cipher *sc = alloc(sizeof(*sc));
+
+ 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;
}