+/* This handy macro borrowed from crypto/x509v3/v3_purp.c */
+#define ku_reject(x, usage) \
+ (((x)->ex_flags & EXFLAG_KUSAGE) && !((x)->ex_kusage & (usage)))
+
+int check_srvr_ecc_cert_and_alg(X509 *x, SSL_CIPHER *cs)
+ {
+ unsigned long alg = cs->algorithms;
+ EVP_PKEY *pkey = NULL;
+ int keysize = 0;
+ int signature_nid = 0;
+
+ if (SSL_C_IS_EXPORT(cs))
+ {
+ /* ECDH key length in export ciphers must be <= 163 bits */
+ pkey = X509_get_pubkey(x);
+ if (pkey == NULL) return 0;
+ keysize = EVP_PKEY_bits(pkey);
+ EVP_PKEY_free(pkey);
+ if (keysize > 163) return 0;
+ }
+
+ /* This call populates the ex_flags field correctly */
+ X509_check_purpose(x, -1, 0);
+ if ((x->sig_alg) && (x->sig_alg->algorithm))
+ signature_nid = OBJ_obj2nid(x->sig_alg->algorithm);
+ if (alg & SSL_kECDH)
+ {
+ /* key usage, if present, must allow key agreement */
+ if (ku_reject(x, X509v3_KU_KEY_AGREEMENT))
+ {
+ return 0;
+ }
+ if (alg & SSL_aECDSA)
+ {
+ /* signature alg must be ECDSA */
+ if (signature_nid != NID_ecdsa_with_SHA1)
+ {
+ return 0;
+ }
+ }
+ if (alg & SSL_aRSA)
+ {
+ /* signature alg must be RSA */
+ if ((signature_nid != NID_md5WithRSAEncryption) &&
+ (signature_nid != NID_md4WithRSAEncryption) &&
+ (signature_nid != NID_md2WithRSAEncryption))
+ {
+ return 0;
+ }
+ }
+ }
+ else if (alg & SSL_aECDSA)
+ {
+ /* key usage, if present, must allow signing */
+ if (ku_reject(x, X509v3_KU_DIGITAL_SIGNATURE))
+ {
+ return 0;
+ }
+ }
+
+ return 1; /* all checks are ok */
+ }
+