#include "crypt_backend.h"
#include "fd.h"
#include "base64.h"
+#include "portable_io.h"
//#define GCRYPT_DEBUG 1
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)
+/** Private PEM keys (legacy format) start with this header. */
+#define PRIVATE_PEM_KEY_HEADER "-----BEGIN RSA PRIVATE KEY-----"
+/** Private OPENSSH keys (RFC4716) start with this header. */
+#define PRIVATE_OPENSSH_KEY_HEADER "-----BEGIN OPENSSH PRIVATE KEY-----"
+/** Private PEM keys (legacy format) end with this footer. */
+#define PRIVATE_PEM_KEY_FOOTER "-----END RSA PRIVATE KEY-----"
+/** Private OPENSSH keys (RFC4716) end with this footer. */
+#define PRIVATE_OPENSSH_KEY_FOOTER "-----END OPENSSH PRIVATE KEY-----"
+/** Legacy PEM keys (openssh-7.7 and earlier, paraslash.0.6.2 and earlier) */
+#define PKT_PEM (0)
+/** OPENSSH keys (since openssh-7.8, paraslash.0.6.3) */
+#define PKT_OPENSSH (1)
+
+static int decode_private_key(const char *key_file, unsigned char **result,
+ size_t *blob_size)
{
- int ret, ret2, i, j;
+ int ret, ret2, i, j, key_type;
void *map;
- size_t map_size, key_size, blob_size;
+ size_t map_size, key_size;
unsigned char *blob = NULL;
char *begin, *footer, *key;
if (ret < 0)
goto out;
ret = -E_KEY_MARKER;
- if (strncmp(map, header_str, strlen(header_str)))
+ if (strncmp(map, PRIVATE_PEM_KEY_HEADER,
+ strlen(PRIVATE_PEM_KEY_HEADER)) == 0) {
+ key_type = PKT_PEM;
+ begin = map + strlen(PRIVATE_PEM_KEY_HEADER);
+ footer = strstr(map, PRIVATE_PEM_KEY_FOOTER);
+ PARA_INFO_LOG("detected legacy PEM key %s\n", key_file);
+ } else if (strncmp(map, PRIVATE_OPENSSH_KEY_HEADER,
+ strlen(PRIVATE_OPENSSH_KEY_HEADER)) == 0) {
+ key_type = PKT_OPENSSH;
+ begin = map + strlen(PRIVATE_OPENSSH_KEY_HEADER);
+ footer = strstr(map, PRIVATE_OPENSSH_KEY_FOOTER);
+ PARA_INFO_LOG("detected openssh key %s\n", key_file);
+ } else
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))
key[j++] = begin[i];
}
key[j] = '\0';
- ret = base64_decode(key, j, (char **)&blob, &blob_size);
+ ret = base64_decode(key, j, (char **)&blob, blob_size);
free(key);
if (ret < 0)
- goto free_unmap;
- ret = blob_size;
- goto unmap;
-free_unmap:
- free(blob);
- blob = NULL;
+ goto unmap;
+ ret = key_type;
unmap:
ret2 = para_munmap(map, map_size);
if (ret >= 0 && ret2 < 0)
/*
* 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;
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;
- *result = NULL;
- 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;
+ goto release_p;
+ return bits;
+release_p:
+ gcry_mpi_release(p->p);
+release_u:
+ gcry_mpi_release(p->u);
+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 get_private_key(const char *key_file, struct asymmetric_key **result)
+{
+ struct rsa_params params;
+ unsigned char *blob, *end;
+ unsigned bits;
+ int ret, key_type;
+ gcry_error_t gret;
+ size_t erroff, blob_size;
+ gcry_sexp_t sexp;
+ struct asymmetric_key *key;
+
+ *result = NULL;
+ ret = decode_private_key(key_file, &blob, &blob_size);
+ if (ret < 0)
+ return ret;
+ key_type = ret;
+ end = 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_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;
+ 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(p, q) > 0) {
- gcry_mpi_swap(p, q);
- gcry_mpi_invm(u, p, q);
+ 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,
- n, e, d, p, q, u);
+ gret = gcry_sexp_build(&sexp, &erroff, RSA_PRIVKEY_SEXP, params.n,
+ params.e, params.d, params.p, params.q, params.u);
if (gret) {
PARA_ERROR_LOG("offset %zu: %s\n", erroff,
gcry_strerror(gcry_err_code(gret)));
ret = -E_SEXP_BUILD;
- goto release_u;
+ goto free_params;
}
key = para_malloc(sizeof(*key));
key->sexp = sexp;
*result = key;
- ret = n_size * 8;
+ ret = bits;
PARA_INFO_LOG("succesfully read %d bit private key\n", ret);
-release_u:
- gcry_mpi_release(u);
-release_q:
- gcry_mpi_release(q);
-release_p:
- gcry_mpi_release(p);
-release_d:
- gcry_mpi_release(d);
-release_e:
- gcry_mpi_release(e);
-release_n:
- gcry_mpi_release(n);
+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);
+
free_blob:
free(blob);
return ret;
unsigned char *blob, *p, *end;
int ret;
gcry_error_t gret;
- size_t nr_scanned, erroff, decoded_size;
+ size_t erroff, decoded_size;
gcry_mpi_t e, n;
gcry_sexp_t sexp;
struct asymmetric_key *key;
+ unsigned bits;
- ret = decode_ssh_key(key_file, &blob, &decoded_size);
+ ret = decode_public_key(key_file, &blob, &decoded_size);
if (ret < 0)
return ret;
p = blob + ret;
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);
- 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);
gret = gcry_sexp_build(&sexp, &erroff, RSA_PUBKEY_SEXP, n, e);
if (gret) {
PARA_ERROR_LOG("offset %zu: %s\n", erroff,
ret = -E_SEXP_BUILD;
goto release_n;
}
- ret = ROUND_DOWN(nr_scanned, 32);
- PARA_INFO_LOG("successfully read %d bit ssh public key\n", ret * 8);
+ PARA_INFO_LOG("successfully read %u bit ssh public key\n", bits);
key = para_malloc(sizeof(*key));
key->num_bytes = ret;
key->sexp = sexp;
*result = key;
+ ret = bits;
release_n:
gcry_mpi_release(n);
release_e:
projects / paraslash.git / blobdiff