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authorAndreas Schneider <asn@cryptomilk.org>2011-08-22 16:27:38 +0200
committerAndreas Schneider <asn@cryptomilk.org>2011-08-22 18:39:56 +0200
commit5cc98ed7205ba68b88d24c85753fb8e60296d2f7 (patch)
tree697947be534369522b744f2d0b0418fac24779fe
parentbcc0a6d0e0b2945e58af4d1d03a17a084ffc3372 (diff)
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pki: Add ssh_pki_signature_verify_blob().
-rw-r--r--include/libssh/pki.h2
-rw-r--r--include/libssh/pki_priv.h5
-rw-r--r--src/pki.c59
-rw-r--r--src/pki_crypto.c47
-rw-r--r--src/pki_gcrypt.c66
5 files changed, 179 insertions, 0 deletions
diff --git a/include/libssh/pki.h b/include/libssh/pki.h
index 2904192..3e908a6 100644
--- a/include/libssh/pki.h
+++ b/include/libssh/pki.h
@@ -68,6 +68,8 @@ int ssh_pki_export_signature_blob(const ssh_signature sign,
int ssh_pki_import_signature_blob(const ssh_string sig_blob,
const ssh_key pubkey,
ssh_signature *psig);
+int ssh_pki_signature_verify_blob(ssh_session session,
+ ssh_string sig_blob);
/* SSH Public Key Functions */
ssh_string ssh_pki_export_pubkey_blob(const ssh_key key);
diff --git a/include/libssh/pki_priv.h b/include/libssh/pki_priv.h
index e86a96c..3e1ef5d 100644
--- a/include/libssh/pki_priv.h
+++ b/include/libssh/pki_priv.h
@@ -55,6 +55,11 @@ ssh_string pki_signature_to_blob(const ssh_signature sign);
ssh_signature pki_signature_from_blob(const ssh_key pubkey,
const ssh_string sig_blob,
enum ssh_keytypes_e type);
+int pki_signature_verify(ssh_session session,
+ const ssh_signature sig,
+ const ssh_key key,
+ const unsigned char *hash,
+ size_t len);
/* SSH Signing Functions */
struct signature_struct *pki_do_sign(const ssh_key privatekey,
diff --git a/src/pki.c b/src/pki.c
index f209fe4..84ee97a 100644
--- a/src/pki.c
+++ b/src/pki.c
@@ -979,6 +979,65 @@ int ssh_pki_import_signature_blob(const ssh_string sig_blob,
return SSH_OK;
}
+int ssh_pki_signature_verify_blob(ssh_session session,
+ ssh_string sig_blob)
+{
+ unsigned char hash[SHA_DIGEST_LEN + 1] = {0};
+ ssh_signature sig;
+ ssh_key key;
+ int rc;
+
+ rc = ssh_pki_import_pubkey_blob(session->next_crypto->server_pubkey, &key);
+ if (rc < 0) {
+ return SSH_ERROR;
+ }
+
+ if (session->wanted_methods[SSH_HOSTKEYS]) {
+ if(!ssh_match_group(session->wanted_methods[SSH_HOSTKEYS],
+ key->type_c)) {
+ ssh_set_error(session,
+ SSH_FATAL,
+ "Public key from server (%s) doesn't match user "
+ "preference (%s)",
+ key->type_c,
+ session->wanted_methods[SSH_HOSTKEYS]);
+ ssh_key_free(key);
+ return -1;
+ }
+ }
+
+ rc = ssh_pki_import_signature_blob(sig_blob, key, &sig);
+ if (rc < 0) {
+ ssh_key_free(key);
+ return SSH_ERROR;
+ }
+
+ ssh_log(session,
+ SSH_LOG_FUNCTIONS,
+ "Going to verify a %s type signature",
+ key->type_c);
+
+
+ sha1(session->next_crypto->session_id,
+ session->next_crypto->digest_len,
+ hash + 1);
+
+#ifdef DEBUG_CRYPTO
+ ssh_print_hexa("Hash to be verified with dsa", hash + 1, SHA_DIGEST_LEN);
+#endif
+
+ rc = pki_signature_verify(session,
+ sig,
+ key,
+ hash,
+ SHA_DIGEST_LEN);
+ session->next_crypto->server_pubkey_type = key->type_c;
+ ssh_signature_free(sig);
+ ssh_key_free(key);
+
+ return rc;
+}
+
/*
* This function signs the session id (known as H) as a string then
* the content of sigbuf */
diff --git a/src/pki_crypto.c b/src/pki_crypto.c
index d4f48d3..386ac99 100644
--- a/src/pki_crypto.c
+++ b/src/pki_crypto.c
@@ -673,6 +673,53 @@ ssh_signature pki_signature_from_blob(const ssh_key pubkey,
return sig;
}
+int pki_signature_verify(ssh_session session,
+ const ssh_signature sig,
+ const ssh_key key,
+ const unsigned char *hash,
+ size_t len)
+{
+ int rc;
+
+ switch(key->type) {
+ case SSH_KEYTYPE_DSS:
+ rc = DSA_do_verify(hash + 1,
+ len,
+ sig->dsa_sig,
+ key->dsa);
+ if (rc < 0) {
+ ssh_set_error(session,
+ SSH_FATAL,
+ "DSA error: %s",
+ ERR_error_string(ERR_get_error(), NULL));
+ return SSH_ERROR;
+ }
+ break;
+ case SSH_KEYTYPE_RSA:
+ case SSH_KEYTYPE_RSA1:
+ rc = RSA_verify(NID_sha1,
+ hash + 1,
+ len,
+ string_data(sig->rsa_sig),
+ ssh_string_len(sig->rsa_sig),
+ key->rsa);
+ if (rc < 0) {
+ ssh_set_error(session,
+ SSH_FATAL,
+ "RSA error: %s",
+ ERR_error_string(ERR_get_error(), NULL));
+ return SSH_ERROR;
+ }
+ break;
+ case SSH_KEYTYPE_ECDSA:
+ case SSH_KEYTYPE_UNKNOWN:
+ ssh_set_error(session, SSH_FATAL, "Unknown public key type");
+ return SSH_ERROR;
+ }
+
+ return SSH_OK;
+}
+
struct signature_struct *pki_do_sign(ssh_key privatekey,
const unsigned char *hash) {
struct signature_struct *sign;
diff --git a/src/pki_gcrypt.c b/src/pki_gcrypt.c
index 3f7a4d9..116e5b0 100644
--- a/src/pki_gcrypt.c
+++ b/src/pki_gcrypt.c
@@ -1313,6 +1313,72 @@ ssh_signature pki_signature_from_blob(const ssh_key pubkey,
return sig;
}
+int pki_signature_verify(ssh_session session,
+ const ssh_signature sig,
+ const ssh_key key,
+ const unsigned char *hash,
+ size_t len)
+{
+ gcry_sexp_t sexp;
+ gcry_error_t err;
+
+ switch(key->type) {
+ case SSH_KEYTYPE_DSS:
+ err = gcry_sexp_build(&sexp, NULL, "%b", len, hash + 1);
+ if (err) {
+ ssh_set_error(session,
+ SSH_FATAL,
+ "DSA error: %s", gcry_strerror(err));
+ return SSH_ERROR;
+ }
+ err = gcry_pk_verify(sig->dsa_sig, sexp, key->dsa);
+ gcry_sexp_release(sexp);
+ if (err) {
+ ssh_set_error(session, SSH_FATAL, "Invalid DSA signature");
+ if (gcry_err_code(err) != GPG_ERR_BAD_SIGNATURE) {
+ ssh_set_error(session,
+ SSH_FATAL,
+ "DSA verify error: %s",
+ gcry_strerror(err));
+ }
+ return SSH_ERROR;
+ }
+ break;
+ case SSH_KEYTYPE_RSA:
+ case SSH_KEYTYPE_RSA1:
+ err = gcry_sexp_build(&sexp,
+ NULL,
+ "(data(flags pkcs1)(hash sha1 %b))",
+ len, hash + 1);
+ if (err) {
+ ssh_set_error(session,
+ SSH_FATAL,
+ "RSA error: %s",
+ gcry_strerror(err));
+ return SSH_ERROR;
+ }
+ err = gcry_pk_verify(sig->rsa_sig, sexp, key->rsa);
+ gcry_sexp_release(sexp);
+ if (err) {
+ ssh_set_error(session, SSH_FATAL, "Invalid RSA signature");
+ if (gcry_err_code(err) != GPG_ERR_BAD_SIGNATURE) {
+ ssh_set_error(session,
+ SSH_FATAL,
+ "RSA verify error: %s",
+ gcry_strerror(err));
+ }
+ return SSH_ERROR;
+ }
+ break;
+ case SSH_KEYTYPE_ECDSA:
+ case SSH_KEYTYPE_UNKNOWN:
+ ssh_set_error(session, SSH_FATAL, "Unknown public key type");
+ return SSH_ERROR;
+ }
+
+ return SSH_OK;
+}
+
struct signature_struct *pki_do_sign(ssh_key privatekey,
const unsigned char *hash) {
struct signature_struct *sign;