ssh_public_key publickey_from_string(ssh_session session, ssh_string pubkey_s) {
ssh_buffer tmpbuf = NULL;
ssh_string type_s = NULL;
char *type_c = NULL;
int type;
tmpbuf = ssh_buffer_new();
if (tmpbuf == NULL) {
return NULL;
}
if (buffer_add_data(tmpbuf, ssh_string_data(pubkey_s), ssh_string_len(pubkey_s)) < 0) {
goto error;
}
type_s = buffer_get_ssh_string(tmpbuf);
if (type_s == NULL) {
ssh_set_error(session,SSH_FATAL,"Invalid public key format");
goto error;
}
type_c = ssh_string_to_char(type_s);
ssh_string_free(type_s);
if (type_c == NULL) {
goto error;
}
type = ssh_type_from_name(type_c);
SAFE_FREE(type_c);
switch (type) {
case SSH_KEYTYPE_DSS:
return publickey_make_dss(session, tmpbuf);
case SSH_KEYTYPE_RSA:
case SSH_KEYTYPE_RSA1:
return publickey_make_rsa(session, tmpbuf, type);
}
ssh_set_error(session, SSH_FATAL, "Unknown public key protocol %s",
ssh_type_to_char(type));
error:
ssh_buffer_free(tmpbuf);
return NULL;
}
PUBLIC_KEY *publickey_from_string(SSH_SESSION *session, STRING *pubkey_s) {
BUFFER *tmpbuf = NULL;
STRING *type_s = NULL;
char *type_c = NULL;
int type;
tmpbuf = buffer_new();
if (tmpbuf == NULL) {
return NULL;
}
if (buffer_add_data(tmpbuf, pubkey_s->string, string_len(pubkey_s)) < 0) {
goto error;
}
type_s = buffer_get_ssh_string(tmpbuf);
if (type_s == NULL) {
ssh_set_error(session,SSH_FATAL,"Invalid public key format");
goto error;
}
type_c = string_to_char(type_s);
string_free(type_s);
if (type_c == NULL) {
goto error;
}
type = ssh_type_from_name(type_c);
SAFE_FREE(type_c);
switch (type) {
case TYPE_DSS:
return publickey_make_dss(session, tmpbuf);
case TYPE_RSA:
case TYPE_RSA1:
return publickey_make_rsa(session, tmpbuf, type);
}
ssh_set_error(session, SSH_FATAL, "Unknown public key protocol %s",
ssh_type_to_char(type));
error:
buffer_free(tmpbuf);
return NULL;
}
/* TODO : split this function in two so it becomes smaller */
SIGNATURE *signature_from_string(ssh_session session, ssh_string signature,
ssh_public_key pubkey, int needed_type) {
SIGNATURE *sign = NULL;
ssh_buffer tmpbuf = NULL;
ssh_string rs = NULL;
ssh_string type_s = NULL;
ssh_string e = NULL;
char *type_c = NULL;
int type;
int len;
int rsalen;
#ifdef HAVE_LIBGCRYPT
gcry_sexp_t sig;
#elif defined HAVE_LIBCRYPTO
DSA_SIG *sig = NULL;
ssh_string r = NULL;
ssh_string s = NULL;
#endif
sign = malloc(sizeof(SIGNATURE));
if (sign == NULL) {
ssh_set_error(session, SSH_FATAL, "Not enough space");
return NULL;
}
ZERO_STRUCTP(sign);
tmpbuf = ssh_buffer_new();
if (tmpbuf == NULL) {
ssh_set_error(session, SSH_FATAL, "Not enough space");
signature_free(sign);
return NULL;
}
if (buffer_add_data(tmpbuf, ssh_string_data(signature), ssh_string_len(signature)) < 0) {
signature_free(sign);
ssh_buffer_free(tmpbuf);
return NULL;
}
type_s = buffer_get_ssh_string(tmpbuf);
if (type_s == NULL) {
ssh_set_error(session, SSH_FATAL, "Invalid signature packet");
signature_free(sign);
ssh_buffer_free(tmpbuf);
return NULL;
}
type_c = ssh_string_to_char(type_s);
ssh_string_free(type_s);
if (type_c == NULL) {
signature_free(sign);
ssh_buffer_free(tmpbuf);
return NULL;
}
type = ssh_type_from_name(type_c);
SAFE_FREE(type_c);
if (needed_type != type) {
ssh_set_error(session, SSH_FATAL, "Invalid signature type: %s",
ssh_type_to_char(type));
signature_free(sign);
ssh_buffer_free(tmpbuf);
return NULL;
}
switch(needed_type) {
case SSH_KEYTYPE_DSS:
rs = buffer_get_ssh_string(tmpbuf);
ssh_buffer_free(tmpbuf);
/* 40 is the dual signature blob len. */
if (rs == NULL || ssh_string_len(rs) != 40) {
ssh_string_free(rs);
signature_free(sign);
return NULL;
}
/* we make use of strings (because we have all-made functions to convert
* them to bignums (ou pas ;) */
#ifdef HAVE_LIBGCRYPT
if (gcry_sexp_build(&sig, NULL, "(sig-val(dsa(r %b)(s %b)))",
20 ,ssh_string_data(rs), 20,(unsigned char *)ssh_string_data(rs) + 20)) {
ssh_string_free(rs);
signature_free(sign);
return NULL;
}
#elif defined HAVE_LIBCRYPTO
r = ssh_string_new(20);
s = ssh_string_new(20);
if (r == NULL || s == NULL) {
ssh_string_free(r);
ssh_string_free(s);
ssh_string_free(rs);
signature_free(sign);
return NULL;
}
ssh_string_fill(r, ssh_string_data(rs), 20);
ssh_string_fill(s, (char *)ssh_string_data(rs) + 20, 20);
sig = DSA_SIG_new();
if (sig == NULL) {
ssh_string_free(r);
ssh_string_free(s);
ssh_string_free(rs);
signature_free(sign);
return NULL;
}
sig->r = make_string_bn(r); /* is that really portable ? Openssh's hack isn't better */
sig->s = make_string_bn(s);
ssh_string_free(r);
ssh_string_free(s);
if (sig->r == NULL || sig->s == NULL) {
ssh_string_free(rs);
DSA_SIG_free(sig);
signature_free(sign);
return NULL;
}
#endif
#ifdef DEBUG_CRYPTO
ssh_print_hexa("r", ssh_string_data(rs), 20);
ssh_print_hexa("s", (const unsigned char *)ssh_string_data(rs) + 20, 20);
#endif
ssh_string_free(rs);
sign->type = SSH_KEYTYPE_DSS;
sign->dsa_sign = sig;
return sign;
case SSH_KEYTYPE_RSA:
e = buffer_get_ssh_string(tmpbuf);
ssh_buffer_free(tmpbuf);
if (e == NULL) {
signature_free(sign);
return NULL;
}
len = ssh_string_len(e);
#ifdef HAVE_LIBGCRYPT
rsalen = (gcry_pk_get_nbits(pubkey->rsa_pub) + 7) / 8;
#elif defined HAVE_LIBCRYPTO
rsalen = RSA_size(pubkey->rsa_pub);
#endif
if (len > rsalen) {
ssh_string_free(e);
signature_free(sign);
ssh_set_error(session, SSH_FATAL, "Signature too big! %d instead of %d",
len, rsalen);
return NULL;
}
if (len < rsalen) {
ssh_log(session, SSH_LOG_RARE, "RSA signature len %d < %d",
len, rsalen);
}
sign->type = SSH_KEYTYPE_RSA;
#ifdef HAVE_LIBGCRYPT
if (gcry_sexp_build(&sig, NULL, "(sig-val(rsa(s %b)))",
ssh_string_len(e), ssh_string_data(e))) {
signature_free(sign);
ssh_string_free(e);
return NULL;
}
sign->rsa_sign = sig;
#elif defined HAVE_LIBCRYPTO
sign->rsa_sign = e;
#endif
#ifdef DEBUG_CRYPTO
ssh_log(session, SSH_LOG_FUNCTIONS, "len e: %d", len);
ssh_print_hexa("RSA signature", ssh_string_data(e), len);
#endif
#ifdef HAVE_LIBGCRYPT
ssh_string_free(e);
#endif
return sign;
default:
return NULL;
}
return NULL;
}
