Parsing of PKCS#8 encrypted private key files added and PKCS#12 basis
PKCS#8 encrypted key file support has been added to x509parse_key() with
support for some PCKS#12 PBE functions (pbeWithSHAAnd128BitRC4,
pbeWithSHAAnd3-KeyTripleDES-CBC and pbeWithSHAAnd2-KeyTripleDES-CBC)
diff --git a/library/x509parse.c b/library/x509parse.c
index 1906df6..ce75d59 100644
--- a/library/x509parse.c
+++ b/library/x509parse.c
@@ -61,6 +61,7 @@
#include "polarssl/sha4.h"
#endif
#include "polarssl/dhm.h"
+#include "polarssl/pkcs12.h"
#include <string.h>
#include <stdlib.h>
@@ -78,6 +79,11 @@
#endif
#endif
+/* Compare a given OID string with an OID x509_buf * */
+#define OID_CMP(oid_str, oid_buf) \
+ ( ( OID_SIZE(oid_str) == (oid_buf)->len ) && \
+ memcmp( (oid_str), (oid_buf)->p, (oid_buf)->len) == 0)
+
/*
* Version ::= INTEGER { v1(0), v2(1), v3(2) }
*/
@@ -2190,6 +2196,116 @@
}
/*
+ * Parse an unencrypted PKCS#8 encoded private RSA key
+ */
+static int x509parse_key_pkcs8_encrypted_der(
+ rsa_context *rsa,
+ const unsigned char *key,
+ size_t keylen,
+ const unsigned char *pwd,
+ size_t pwdlen )
+{
+ int ret;
+ size_t len;
+ unsigned char *p, *end, *end2;
+ x509_buf pbe_alg_oid, pbe_params;
+ unsigned char buf[2048];
+
+ memset(buf, 0, 2048);
+
+ p = (unsigned char *) key;
+ end = p + keylen;
+
+ /*
+ * This function parses the EncryptedPrivatKeyInfo object (PKCS#8)
+ *
+ * EncryptedPrivateKeyInfo ::= SEQUENCE {
+ * encryptionAlgorithm EncryptionAlgorithmIdentifier,
+ * encryptedData EncryptedData
+ * }
+ *
+ * EncryptionAlgorithmIdentifier ::= AlgorithmIdentifier
+ *
+ * EncryptedData ::= OCTET STRING
+ *
+ * The EncryptedData OCTET STRING is a PKCS#8 PrivateKeyInfo
+ */
+ if( ( ret = asn1_get_tag( &p, end, &len,
+ ASN1_CONSTRUCTED | ASN1_SEQUENCE ) ) != 0 )
+ {
+ return( POLARSSL_ERR_X509_KEY_INVALID_FORMAT + ret );
+ }
+
+ end = p + len;
+
+ if( ( ret = asn1_get_tag( &p, end, &len,
+ ASN1_CONSTRUCTED | ASN1_SEQUENCE ) ) != 0 )
+ {
+ return( POLARSSL_ERR_X509_KEY_INVALID_FORMAT + ret );
+ }
+
+ end2 = p + len;
+
+ if( ( ret = asn1_get_tag( &p, end, &pbe_alg_oid.len, ASN1_OID ) ) != 0 )
+ return( POLARSSL_ERR_X509_KEY_INVALID_FORMAT + ret );
+
+ pbe_alg_oid.p = p;
+ p += pbe_alg_oid.len;
+
+ /*
+ * Store the algorithm parameters
+ */
+ pbe_params.p = p;
+ pbe_params.len = end2 - p;
+ p += pbe_params.len;
+
+ if( ( ret = asn1_get_tag( &p, end, &len, ASN1_OCTET_STRING ) ) != 0 )
+ return( POLARSSL_ERR_X509_KEY_INVALID_FORMAT + ret );
+
+ // buf has been sized to 2048 bytes
+ if( len > 2048 )
+ return( POLARSSL_ERR_X509_INVALID_INPUT );
+
+ /*
+ * Decrypt EncryptedData with appropriate PDE
+ */
+ if( OID_CMP( OID_PKCS12_PBE_SHA1_DES3_EDE_CBC, &pbe_alg_oid ) )
+ {
+ if( ( ret = pkcs12_pbe_sha1_des3_ede_cbc( &pbe_params,
+ PKCS12_PBE_DECRYPT,
+ pwd, pwdlen,
+ p, len, buf ) ) != 0 )
+ {
+ return( ret );
+ }
+ }
+ else if( OID_CMP( OID_PKCS12_PBE_SHA1_DES2_EDE_CBC, &pbe_alg_oid ) )
+ {
+ if( ( ret = pkcs12_pbe_sha1_des2_ede_cbc( &pbe_params,
+ PKCS12_PBE_DECRYPT,
+ pwd, pwdlen,
+ p, len, buf ) ) != 0 )
+ {
+ return( ret );
+ }
+ }
+ else if( OID_CMP( OID_PKCS12_PBE_SHA1_RC4_128, &pbe_alg_oid ) )
+ {
+ if( ( ret = pkcs12_pbe_sha1_rc4_128( &pbe_params,
+ PKCS12_PBE_DECRYPT,
+ pwd, pwdlen,
+ p, len, buf ) ) != 0 )
+ {
+ return( ret );
+ }
+ }
+ else
+ return( POLARSSL_ERR_X509_FEATURE_UNAVAILABLE );
+
+ return x509parse_key_pkcs8_unencrypted_der( rsa, buf, len );
+}
+
+/*
* Parse a private RSA key
*/
int x509parse_key( rsa_context *rsa, const unsigned char *key, size_t keylen,
@@ -2243,7 +2359,27 @@
return( ret );
}
- pem_free( &pem );
+ ret = pem_read_buffer( &pem,
+ "-----BEGIN ENCRYPTED PRIVATE KEY-----",
+ "-----END ENCRYPTED PRIVATE KEY-----",
+ key, NULL, 0, &len );
+ if( ret == 0 )
+ {
+ if( ( ret = x509parse_key_pkcs8_encrypted_der( rsa,
+ pem.buf, pem.buflen,
+ pwd, pwdlen ) ) != 0 )
+ {
+ rsa_free( rsa );
+ }
+
+ pem_free( &pem );
+ return( ret );
+ }
+ else if( ret != POLARSSL_ERR_PEM_NO_HEADER_FOOTER_PRESENT )
+ {
+ pem_free( &pem );
+ return( ret );
+ }
#else
((void) pwd);
((void) pwdlen);
@@ -2255,18 +2391,22 @@
// We try the different DER format parsers to see if one passes without
// error
//
- if( ( ret = x509parse_key_pkcs8_unencrypted_der( rsa, key, keylen ) ) != 0 )
+ if( ( ret = x509parse_key_pkcs8_encrypted_der( rsa, key, keylen,
+ pwd, pwdlen ) ) == 0 )
{
- rsa_free( rsa );
-
- if( ( ret = x509parse_key_pkcs1_der( rsa, key, keylen ) ) != 0 )
- {
- rsa_free( rsa );
- return( POLARSSL_ERR_X509_KEY_INVALID_FORMAT );
- }
+ return( 0 );
}
- return( 0 );
+ rsa_free( rsa );
+ if( ( ret = x509parse_key_pkcs8_unencrypted_der( rsa, key, keylen ) ) == 0 )
+ return( 0 );
+
+ rsa_free( rsa );
+ if( ( ret = x509parse_key_pkcs1_der( rsa, key, keylen ) ) == 0 )
+ return( 0 );
+
+ rsa_free( rsa );
+ return( POLARSSL_ERR_X509_KEY_INVALID_FORMAT );
}
/*
@@ -2726,11 +2866,6 @@
return( (int) ( size - n ) );
}
-/* Compare a given OID string with an OID x509_buf * */
-#define OID_CMP(oid_str, oid_buf) \
- ( ( OID_SIZE(oid_str) == (oid_buf)->len ) && \
- memcmp( (oid_str), (oid_buf)->p, (oid_buf)->len) == 0)
-
/*
* Return an informational string describing the given OID
*/