version 1.17, 2020/10/18 11:32:02 |
version 1.18, 2023/07/19 14:03:45 |
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#include <string.h> |
#include <string.h> |
#include <unistd.h> |
#include <unistd.h> |
#include <errno.h> |
#include <errno.h> |
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#include <limits.h> |
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#include <openssl/ecdsa.h> |
#include <openssl/ecdsa.h> |
#include <openssl/rsa.h> |
#include <openssl/rsa.h> |
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/* borrows code from sftp-server and ssh-agent */ |
/* borrows code from sftp-server and ssh-agent */ |
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static int fd = -1; |
/* |
static pid_t pid = -1; |
* Maintain a list of ssh-pkcs11-helper subprocesses. These may be looked up |
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* by provider path or their unique EC/RSA METHOD pointers. |
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*/ |
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struct helper { |
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char *path; |
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pid_t pid; |
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int fd; |
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RSA_METHOD *rsa_meth; |
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EC_KEY_METHOD *ec_meth; |
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int (*rsa_finish)(RSA *rsa); |
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void (*ec_finish)(EC_KEY *key); |
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size_t nrsa, nec; /* number of active keys of each type */ |
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}; |
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static struct helper **helpers; |
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static size_t nhelpers; |
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static struct helper * |
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helper_by_provider(const char *path) |
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{ |
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size_t i; |
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for (i = 0; i < nhelpers; i++) { |
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if (helpers[i] == NULL || helpers[i]->path == NULL || |
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helpers[i]->fd == -1) |
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continue; |
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if (strcmp(helpers[i]->path, path) == 0) |
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return helpers[i]; |
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} |
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return NULL; |
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} |
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static struct helper * |
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helper_by_rsa(const RSA *rsa) |
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{ |
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size_t i; |
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const RSA_METHOD *meth; |
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if ((meth = RSA_get_method(rsa)) == NULL) |
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return NULL; |
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for (i = 0; i < nhelpers; i++) { |
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if (helpers[i] != NULL && helpers[i]->rsa_meth == meth) |
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return helpers[i]; |
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} |
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return NULL; |
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} |
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static struct helper * |
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helper_by_ec(const EC_KEY *ec) |
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{ |
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size_t i; |
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const EC_KEY_METHOD *meth; |
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if ((meth = EC_KEY_get_method(ec)) == NULL) |
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return NULL; |
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for (i = 0; i < nhelpers; i++) { |
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if (helpers[i] != NULL && helpers[i]->ec_meth == meth) |
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return helpers[i]; |
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} |
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return NULL; |
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} |
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static void |
static void |
send_msg(struct sshbuf *m) |
helper_free(struct helper *helper) |
{ |
{ |
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size_t i; |
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int found = 0; |
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if (helper == NULL) |
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return; |
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if (helper->path == NULL || helper->ec_meth == NULL || |
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helper->rsa_meth == NULL) |
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fatal_f("inconsistent helper"); |
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debug3_f("free helper for provider %s", helper->path); |
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for (i = 0; i < nhelpers; i++) { |
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if (helpers[i] == helper) { |
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if (found) |
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fatal_f("helper recorded more than once"); |
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found = 1; |
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} |
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else if (found) |
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helpers[i - 1] = helpers[i]; |
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} |
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if (found) { |
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helpers = xrecallocarray(helpers, nhelpers, |
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nhelpers - 1, sizeof(*helpers)); |
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nhelpers--; |
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} |
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free(helper->path); |
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EC_KEY_METHOD_free(helper->ec_meth); |
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RSA_meth_free(helper->rsa_meth); |
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free(helper); |
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} |
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static void |
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helper_terminate(struct helper *helper) |
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{ |
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if (helper == NULL) { |
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return; |
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} else if (helper->fd == -1) { |
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debug3_f("already terminated"); |
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} else { |
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debug3_f("terminating helper for %s; " |
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"remaining %zu RSA %zu ECDSA", |
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helper->path, helper->nrsa, helper->nec); |
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close(helper->fd); |
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/* XXX waitpid() */ |
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helper->fd = -1; |
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helper->pid = -1; |
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} |
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/* |
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* Don't delete the helper entry until there are no remaining keys |
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* that reference it. Otherwise, any signing operation would call |
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* a free'd METHOD pointer and that would be bad. |
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*/ |
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if (helper->nrsa == 0 && helper->nec == 0) |
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helper_free(helper); |
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} |
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static void |
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send_msg(int fd, struct sshbuf *m) |
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{ |
u_char buf[4]; |
u_char buf[4]; |
size_t mlen = sshbuf_len(m); |
size_t mlen = sshbuf_len(m); |
int r; |
int r; |
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if (fd == -1) |
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return; |
POKE_U32(buf, mlen); |
POKE_U32(buf, mlen); |
if (atomicio(vwrite, fd, buf, 4) != 4 || |
if (atomicio(vwrite, fd, buf, 4) != 4 || |
atomicio(vwrite, fd, sshbuf_mutable_ptr(m), |
atomicio(vwrite, fd, sshbuf_mutable_ptr(m), |
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} |
} |
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static int |
static int |
recv_msg(struct sshbuf *m) |
recv_msg(int fd, struct sshbuf *m) |
{ |
{ |
u_int l, len; |
u_int l, len; |
u_char c, buf[1024]; |
u_char c, buf[1024]; |
int r; |
int r; |
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sshbuf_reset(m); |
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if (fd == -1) |
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return 0; /* XXX */ |
if ((len = atomicio(read, fd, buf, 4)) != 4) { |
if ((len = atomicio(read, fd, buf, 4)) != 4) { |
error("read from helper failed: %u", len); |
error("read from helper failed: %u", len); |
return (0); /* XXX */ |
return (0); /* XXX */ |
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if (len > 256 * 1024) |
if (len > 256 * 1024) |
fatal("response too long: %u", len); |
fatal("response too long: %u", len); |
/* read len bytes into m */ |
/* read len bytes into m */ |
sshbuf_reset(m); |
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while (len > 0) { |
while (len > 0) { |
l = len; |
l = len; |
if (l > sizeof(buf)) |
if (l > sizeof(buf)) |
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int |
int |
pkcs11_init(int interactive) |
pkcs11_init(int interactive) |
{ |
{ |
return (0); |
return 0; |
} |
} |
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void |
void |
pkcs11_terminate(void) |
pkcs11_terminate(void) |
{ |
{ |
if (fd >= 0) |
size_t i; |
close(fd); |
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debug3_f("terminating %zu helpers", nhelpers); |
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for (i = 0; i < nhelpers; i++) |
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helper_terminate(helpers[i]); |
} |
} |
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static int |
static int |
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u_char *blob = NULL, *signature = NULL; |
u_char *blob = NULL, *signature = NULL; |
size_t blen, slen = 0; |
size_t blen, slen = 0; |
int r, ret = -1; |
int r, ret = -1; |
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struct helper *helper; |
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if ((helper = helper_by_rsa(rsa)) == NULL || helper->fd == -1) |
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fatal_f("no helper for PKCS11 key"); |
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debug3_f("signing with PKCS11 provider %s", helper->path); |
if (padding != RSA_PKCS1_PADDING) |
if (padding != RSA_PKCS1_PADDING) |
goto fail; |
goto fail; |
key = sshkey_new(KEY_UNSPEC); |
key = sshkey_new(KEY_UNSPEC); |
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(r = sshbuf_put_string(msg, from, flen)) != 0 || |
(r = sshbuf_put_string(msg, from, flen)) != 0 || |
(r = sshbuf_put_u32(msg, 0)) != 0) |
(r = sshbuf_put_u32(msg, 0)) != 0) |
fatal_fr(r, "compose"); |
fatal_fr(r, "compose"); |
send_msg(msg); |
send_msg(helper->fd, msg); |
sshbuf_reset(msg); |
sshbuf_reset(msg); |
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if (recv_msg(msg) == SSH2_AGENT_SIGN_RESPONSE) { |
if (recv_msg(helper->fd, msg) == SSH2_AGENT_SIGN_RESPONSE) { |
if ((r = sshbuf_get_string(msg, &signature, &slen)) != 0) |
if ((r = sshbuf_get_string(msg, &signature, &slen)) != 0) |
fatal_fr(r, "parse"); |
fatal_fr(r, "parse"); |
if (slen <= (size_t)RSA_size(rsa)) { |
if (slen <= (size_t)RSA_size(rsa)) { |
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return (ret); |
return (ret); |
} |
} |
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static int |
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rsa_finish(RSA *rsa) |
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{ |
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struct helper *helper; |
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if ((helper = helper_by_rsa(rsa)) == NULL) |
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fatal_f("no helper for PKCS11 key"); |
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debug3_f("free PKCS11 RSA key for provider %s", helper->path); |
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if (helper->rsa_finish != NULL) |
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helper->rsa_finish(rsa); |
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if (helper->nrsa == 0) |
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fatal_f("RSA refcount error"); |
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helper->nrsa--; |
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debug3_f("provider %s remaining keys: %zu RSA %zu ECDSA", |
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helper->path, helper->nrsa, helper->nec); |
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if (helper->nrsa == 0 && helper->nec == 0) |
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helper_terminate(helper); |
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return 1; |
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} |
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static ECDSA_SIG * |
static ECDSA_SIG * |
ecdsa_do_sign(const unsigned char *dgst, int dgst_len, const BIGNUM *inv, |
ecdsa_do_sign(const unsigned char *dgst, int dgst_len, const BIGNUM *inv, |
const BIGNUM *rp, EC_KEY *ec) |
const BIGNUM *rp, EC_KEY *ec) |
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u_char *blob = NULL, *signature = NULL; |
u_char *blob = NULL, *signature = NULL; |
size_t blen, slen = 0; |
size_t blen, slen = 0; |
int r, nid; |
int r, nid; |
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struct helper *helper; |
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if ((helper = helper_by_ec(ec)) == NULL || helper->fd == -1) |
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fatal_f("no helper for PKCS11 key"); |
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debug3_f("signing with PKCS11 provider %s", helper->path); |
nid = sshkey_ecdsa_key_to_nid(ec); |
nid = sshkey_ecdsa_key_to_nid(ec); |
if (nid < 0) { |
if (nid < 0) { |
error_f("couldn't get curve nid"); |
error_f("couldn't get curve nid"); |
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(r = sshbuf_put_string(msg, dgst, dgst_len)) != 0 || |
(r = sshbuf_put_string(msg, dgst, dgst_len)) != 0 || |
(r = sshbuf_put_u32(msg, 0)) != 0) |
(r = sshbuf_put_u32(msg, 0)) != 0) |
fatal_fr(r, "compose"); |
fatal_fr(r, "compose"); |
send_msg(msg); |
send_msg(helper->fd, msg); |
sshbuf_reset(msg); |
sshbuf_reset(msg); |
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if (recv_msg(msg) == SSH2_AGENT_SIGN_RESPONSE) { |
if (recv_msg(helper->fd, msg) == SSH2_AGENT_SIGN_RESPONSE) { |
if ((r = sshbuf_get_string(msg, &signature, &slen)) != 0) |
if ((r = sshbuf_get_string(msg, &signature, &slen)) != 0) |
fatal_fr(r, "parse"); |
fatal_fr(r, "parse"); |
cp = signature; |
cp = signature; |
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return (ret); |
return (ret); |
} |
} |
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static RSA_METHOD *helper_rsa; |
static void |
static EC_KEY_METHOD *helper_ecdsa; |
ecdsa_do_finish(EC_KEY *ec) |
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{ |
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struct helper *helper; |
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if ((helper = helper_by_ec(ec)) == NULL) |
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fatal_f("no helper for PKCS11 key"); |
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debug3_f("free PKCS11 ECDSA key for provider %s", helper->path); |
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if (helper->ec_finish != NULL) |
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helper->ec_finish(ec); |
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if (helper->nec == 0) |
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fatal_f("ECDSA refcount error"); |
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helper->nec--; |
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debug3_f("provider %s remaining keys: %zu RSA %zu ECDSA", |
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helper->path, helper->nrsa, helper->nec); |
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if (helper->nrsa == 0 && helper->nec == 0) |
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helper_terminate(helper); |
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} |
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/* redirect private key crypto operations to the ssh-pkcs11-helper */ |
/* redirect private key crypto operations to the ssh-pkcs11-helper */ |
static void |
static void |
wrap_key(struct sshkey *k) |
wrap_key(struct helper *helper, struct sshkey *k) |
{ |
{ |
if (k->type == KEY_RSA) |
debug3_f("wrap %s for provider %s", sshkey_type(k), helper->path); |
RSA_set_method(k->rsa, helper_rsa); |
if (k->type == KEY_RSA) { |
else if (k->type == KEY_ECDSA) |
RSA_set_method(k->rsa, helper->rsa_meth); |
EC_KEY_set_method(k->ecdsa, helper_ecdsa); |
if (helper->nrsa++ >= INT_MAX) |
else |
fatal_f("RSA refcount error"); |
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} else if (k->type == KEY_ECDSA) { |
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EC_KEY_set_method(k->ecdsa, helper->ec_meth); |
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if (helper->nec++ >= INT_MAX) |
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fatal_f("EC refcount error"); |
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} else |
fatal_f("unknown key type"); |
fatal_f("unknown key type"); |
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k->flags |= SSHKEY_FLAG_EXT; |
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debug3_f("provider %s remaining keys: %zu RSA %zu ECDSA", |
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helper->path, helper->nrsa, helper->nec); |
} |
} |
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static int |
static int |
pkcs11_start_helper_methods(void) |
pkcs11_start_helper_methods(struct helper *helper) |
{ |
{ |
if (helper_ecdsa != NULL) |
int (*ec_init)(EC_KEY *key); |
return (0); |
int (*ec_copy)(EC_KEY *dest, const EC_KEY *src); |
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int (*ec_set_group)(EC_KEY *key, const EC_GROUP *grp); |
int (*orig_sign)(int, const unsigned char *, int, unsigned char *, |
int (*ec_set_private)(EC_KEY *key, const BIGNUM *priv_key); |
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int (*ec_set_public)(EC_KEY *key, const EC_POINT *pub_key); |
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int (*ec_sign)(int, const unsigned char *, int, unsigned char *, |
unsigned int *, const BIGNUM *, const BIGNUM *, EC_KEY *) = NULL; |
unsigned int *, const BIGNUM *, const BIGNUM *, EC_KEY *) = NULL; |
if (helper_ecdsa != NULL) |
RSA_METHOD *rsa_meth; |
return (0); |
EC_KEY_METHOD *ec_meth; |
helper_ecdsa = EC_KEY_METHOD_new(EC_KEY_OpenSSL()); |
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if (helper_ecdsa == NULL) |
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return (-1); |
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EC_KEY_METHOD_get_sign(helper_ecdsa, &orig_sign, NULL, NULL); |
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EC_KEY_METHOD_set_sign(helper_ecdsa, orig_sign, NULL, ecdsa_do_sign); |
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if ((helper_rsa = RSA_meth_dup(RSA_get_default_method())) == NULL) |
if ((ec_meth = EC_KEY_METHOD_new(EC_KEY_OpenSSL())) == NULL) |
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return -1; |
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EC_KEY_METHOD_get_sign(ec_meth, &ec_sign, NULL, NULL); |
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EC_KEY_METHOD_set_sign(ec_meth, ec_sign, NULL, ecdsa_do_sign); |
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EC_KEY_METHOD_get_init(ec_meth, &ec_init, &helper->ec_finish, |
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&ec_copy, &ec_set_group, &ec_set_private, &ec_set_public); |
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EC_KEY_METHOD_set_init(ec_meth, ec_init, ecdsa_do_finish, |
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ec_copy, ec_set_group, ec_set_private, ec_set_public); |
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if ((rsa_meth = RSA_meth_dup(RSA_get_default_method())) == NULL) |
fatal_f("RSA_meth_dup failed"); |
fatal_f("RSA_meth_dup failed"); |
if (!RSA_meth_set1_name(helper_rsa, "ssh-pkcs11-helper") || |
helper->rsa_finish = RSA_meth_get_finish(rsa_meth); |
!RSA_meth_set_priv_enc(helper_rsa, rsa_encrypt)) |
if (!RSA_meth_set1_name(rsa_meth, "ssh-pkcs11-helper") || |
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!RSA_meth_set_priv_enc(rsa_meth, rsa_encrypt) || |
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!RSA_meth_set_finish(rsa_meth, rsa_finish)) |
fatal_f("failed to prepare method"); |
fatal_f("failed to prepare method"); |
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return (0); |
helper->ec_meth = ec_meth; |
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helper->rsa_meth = rsa_meth; |
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return 0; |
} |
} |
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static int |
static struct helper * |
pkcs11_start_helper(void) |
pkcs11_start_helper(const char *path) |
{ |
{ |
int pair[2]; |
int pair[2]; |
char *helper, *verbosity = NULL; |
char *prog, *verbosity = NULL; |
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struct helper *helper; |
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pid_t pid; |
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if (log_level_get() >= SYSLOG_LEVEL_DEBUG1) |
if (nhelpers >= INT_MAX) |
verbosity = "-vvv"; |
fatal_f("too many helpers"); |
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debug3_f("start helper for %s", path); |
if (pkcs11_start_helper_methods() == -1) { |
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error("pkcs11_start_helper_methods failed"); |
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return (-1); |
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} |
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if (socketpair(AF_UNIX, SOCK_STREAM, 0, pair) == -1) { |
if (socketpair(AF_UNIX, SOCK_STREAM, 0, pair) == -1) { |
error("socketpair: %s", strerror(errno)); |
error_f("socketpair: %s", strerror(errno)); |
return (-1); |
return NULL; |
} |
} |
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helper = xcalloc(1, sizeof(*helper)); |
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if (pkcs11_start_helper_methods(helper) == -1) { |
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error_f("pkcs11_start_helper_methods failed"); |
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goto fail; |
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} |
if ((pid = fork()) == -1) { |
if ((pid = fork()) == -1) { |
error("fork: %s", strerror(errno)); |
error_f("fork: %s", strerror(errno)); |
return (-1); |
fail: |
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close(pair[0]); |
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close(pair[1]); |
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RSA_meth_free(helper->rsa_meth); |
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EC_KEY_METHOD_free(helper->ec_meth); |
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free(helper); |
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return NULL; |
} else if (pid == 0) { |
} else if (pid == 0) { |
if ((dup2(pair[1], STDIN_FILENO) == -1) || |
if ((dup2(pair[1], STDIN_FILENO) == -1) || |
(dup2(pair[1], STDOUT_FILENO) == -1)) { |
(dup2(pair[1], STDOUT_FILENO) == -1)) { |
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} |
} |
close(pair[0]); |
close(pair[0]); |
close(pair[1]); |
close(pair[1]); |
helper = getenv("SSH_PKCS11_HELPER"); |
prog = getenv("SSH_PKCS11_HELPER"); |
if (helper == NULL || strlen(helper) == 0) |
if (prog == NULL || strlen(prog) == 0) |
helper = _PATH_SSH_PKCS11_HELPER; |
prog = _PATH_SSH_PKCS11_HELPER; |
debug_f("starting %s %s", helper, |
if (log_level_get() >= SYSLOG_LEVEL_DEBUG1) |
|
verbosity = "-vvv"; |
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debug_f("starting %s %s", prog, |
verbosity == NULL ? "" : verbosity); |
verbosity == NULL ? "" : verbosity); |
execlp(helper, helper, verbosity, (char *)NULL); |
execlp(prog, prog, verbosity, (char *)NULL); |
fprintf(stderr, "exec: %s: %s\n", helper, strerror(errno)); |
fprintf(stderr, "exec: %s: %s\n", prog, strerror(errno)); |
_exit(1); |
_exit(1); |
} |
} |
close(pair[1]); |
close(pair[1]); |
fd = pair[0]; |
helper->fd = pair[0]; |
return (0); |
helper->path = xstrdup(path); |
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helper->pid = pid; |
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debug3_f("helper %zu for \"%s\" on fd %d pid %ld", nhelpers, |
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helper->path, helper->fd, (long)helper->pid); |
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helpers = xrecallocarray(helpers, nhelpers, |
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nhelpers + 1, sizeof(*helpers)); |
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helpers[nhelpers++] = helper; |
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return helper; |
} |
} |
|
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int |
int |
|
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size_t blen; |
size_t blen; |
u_int nkeys, i; |
u_int nkeys, i; |
struct sshbuf *msg; |
struct sshbuf *msg; |
|
struct helper *helper; |
|
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if (fd < 0 && pkcs11_start_helper() < 0) |
if ((helper = helper_by_provider(name)) == NULL && |
return (-1); |
(helper = pkcs11_start_helper(name)) == NULL) |
|
return -1; |
|
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if ((msg = sshbuf_new()) == NULL) |
if ((msg = sshbuf_new()) == NULL) |
fatal_f("sshbuf_new failed"); |
fatal_f("sshbuf_new failed"); |
|
|
(r = sshbuf_put_cstring(msg, name)) != 0 || |
(r = sshbuf_put_cstring(msg, name)) != 0 || |
(r = sshbuf_put_cstring(msg, pin)) != 0) |
(r = sshbuf_put_cstring(msg, pin)) != 0) |
fatal_fr(r, "compose"); |
fatal_fr(r, "compose"); |
send_msg(msg); |
send_msg(helper->fd, msg); |
sshbuf_reset(msg); |
sshbuf_reset(msg); |
|
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type = recv_msg(msg); |
type = recv_msg(helper->fd, msg); |
if (type == SSH2_AGENT_IDENTITIES_ANSWER) { |
if (type == SSH2_AGENT_IDENTITIES_ANSWER) { |
if ((r = sshbuf_get_u32(msg, &nkeys)) != 0) |
if ((r = sshbuf_get_u32(msg, &nkeys)) != 0) |
fatal_fr(r, "parse nkeys"); |
fatal_fr(r, "parse nkeys"); |
|
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fatal_fr(r, "parse key"); |
fatal_fr(r, "parse key"); |
if ((r = sshkey_from_blob(blob, blen, &k)) != 0) |
if ((r = sshkey_from_blob(blob, blen, &k)) != 0) |
fatal_fr(r, "decode key"); |
fatal_fr(r, "decode key"); |
wrap_key(k); |
wrap_key(helper, k); |
(*keysp)[i] = k; |
(*keysp)[i] = k; |
if (labelsp) |
if (labelsp) |
(*labelsp)[i] = label; |
(*labelsp)[i] = label; |
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int |
int |
pkcs11_del_provider(char *name) |
pkcs11_del_provider(char *name) |
{ |
{ |
int r, ret = -1; |
struct helper *helper; |
struct sshbuf *msg; |
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|
|
if ((msg = sshbuf_new()) == NULL) |
/* |
fatal_f("sshbuf_new failed"); |
* ssh-agent deletes keys before calling this, so the helper entry |
if ((r = sshbuf_put_u8(msg, SSH_AGENTC_REMOVE_SMARTCARD_KEY)) != 0 || |
* should be gone before we get here. |
(r = sshbuf_put_cstring(msg, name)) != 0 || |
*/ |
(r = sshbuf_put_cstring(msg, "")) != 0) |
debug3_f("delete %s", name); |
fatal_fr(r, "compose"); |
if ((helper = helper_by_provider(name)) != NULL) |
send_msg(msg); |
helper_terminate(helper); |
sshbuf_reset(msg); |
return 0; |
|
|
if (recv_msg(msg) == SSH_AGENT_SUCCESS) |
|
ret = 0; |
|
sshbuf_free(msg); |
|
return (ret); |
|
} |
} |