diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/pki_crypto.c | 80 |
1 files changed, 56 insertions, 24 deletions
diff --git a/src/pki_crypto.c b/src/pki_crypto.c index 1080a809..85471f94 100644 --- a/src/pki_crypto.c +++ b/src/pki_crypto.c @@ -1188,6 +1188,61 @@ ssh_string pki_signature_to_blob(const ssh_signature sig) return sig_blob; } +static ssh_signature pki_signature_from_rsa_blob(const ssh_key pubkey, + const ssh_string sig_blob, + ssh_signature sig) +{ + uint32_t pad_len = 0; + char *blob_orig; + char *blob_padded_data; + ssh_string sig_blob_padded; + + size_t len = ssh_string_len(sig_blob); + size_t rsalen= RSA_size(pubkey->rsa); + + if (len > rsalen) { + ssh_pki_log("Signature is too big: %lu > %lu", + (unsigned long)len, (unsigned long)rsalen); + goto errout; + } + +#ifdef DEBUG_CRYPTO + ssh_pki_log("RSA signature len: %lu", (unsigned long)len); + ssh_print_hexa("RSA signature", ssh_string_data(sig_blob), len); +#endif + + if (len == rsalen) { + sig->rsa_sig = ssh_string_copy(sig_blob); + } else { + /* pad the blob to the expected rsalen size */ + ssh_pki_log("RSA signature len %lu < %lu", + (unsigned long)len, (unsigned long)rsalen); + + pad_len = rsalen - len; + + sig_blob_padded = ssh_string_new(rsalen); + if (sig_blob_padded == NULL) { + goto errout; + } + + blob_padded_data = (char *) ssh_string_data(sig_blob_padded); + blob_orig = (char *) ssh_string_data(sig_blob); + + /* front-pad the buffer with zeroes */ + BURN_BUFFER(blob_padded_data, pad_len); + /* fill the rest with the actual signature blob */ + memcpy(blob_padded_data + pad_len, blob_orig, len); + + sig->rsa_sig = sig_blob_padded; + } + + return sig; + +errout: + ssh_signature_free(sig); + return NULL; +} + ssh_signature pki_signature_from_blob(const ssh_key pubkey, const ssh_string sig_blob, enum ssh_keytypes_e type) @@ -1196,7 +1251,6 @@ ssh_signature pki_signature_from_blob(const ssh_key pubkey, ssh_string r; ssh_string s; size_t len; - size_t rsalen; sig = ssh_signature_new(); if (sig == NULL) { @@ -1260,29 +1314,7 @@ ssh_signature pki_signature_from_blob(const ssh_key pubkey, break; case SSH_KEYTYPE_RSA: case SSH_KEYTYPE_RSA1: - rsalen = RSA_size(pubkey->rsa); - - if (len > rsalen) { - ssh_pki_log("Signature is to big size: %lu", - (unsigned long)len); - ssh_signature_free(sig); - return NULL; - } - - if (len < rsalen) { - ssh_pki_log("RSA signature len %lu < %lu", - (unsigned long)len, (unsigned long)rsalen); - } - -#ifdef DEBUG_CRYPTO - ssh_pki_log("RSA signature len: %lu", (unsigned long)len); - ssh_print_hexa("RSA signature", ssh_string_data(sig_blob), len); -#endif - sig->rsa_sig = ssh_string_copy(sig_blob); - if (sig->rsa_sig == NULL) { - ssh_signature_free(sig); - return NULL; - } + sig = pki_signature_from_rsa_blob(pubkey, sig_blob, sig); break; case SSH_KEYTYPE_ECDSA: #ifdef HAVE_OPENSSL_ECC |