]> git.ipfire.org Git - thirdparty/hostap.git/blobdiff - src/eap_common/eap_pwd_common.c
EAP-pwd: Replace direct OpenSSL HMAC use with wrapper
[thirdparty/hostap.git] / src / eap_common / eap_pwd_common.c
index c32f9fb93012150bb8d0e2a73b1b0a89d6fc7884..7d6e6b8898a1694b93555a2567f6ef7387c1cfd8 100644 (file)
@@ -8,70 +8,76 @@
 
 #include "includes.h"
 #include "common.h"
+#include "crypto/sha256.h"
+#include "crypto/crypto.h"
 #include "eap_defs.h"
 #include "eap_pwd_common.h"
 
 /* The random function H(x) = HMAC-SHA256(0^32, x) */
-void H_Init(HMAC_CTX *ctx)
+struct crypto_hash * eap_pwd_h_init(void)
 {
-       u8 allzero[SHA256_DIGEST_LENGTH];
-
-       os_memset(allzero, 0, SHA256_DIGEST_LENGTH);
-       HMAC_Init(ctx, allzero, SHA256_DIGEST_LENGTH, EVP_sha256());
+       u8 allzero[SHA256_MAC_LEN];
+       os_memset(allzero, 0, SHA256_MAC_LEN);
+       return crypto_hash_init(CRYPTO_HASH_ALG_HMAC_SHA256, allzero,
+                               SHA256_MAC_LEN);
 }
 
 
-void H_Update(HMAC_CTX *ctx, const u8 *data, int len)
+void eap_pwd_h_update(struct crypto_hash *hash, const u8 *data, size_t len)
 {
-       HMAC_Update(ctx, data, len);
+       crypto_hash_update(hash, data, len);
 }
 
 
-void H_Final(HMAC_CTX *ctx, u8 *digest)
+void eap_pwd_h_final(struct crypto_hash *hash, u8 *digest)
 {
-       unsigned int mdlen = SHA256_DIGEST_LENGTH;
-
-       HMAC_Final(ctx, digest, &mdlen);
-       HMAC_CTX_cleanup(ctx);
+       size_t len = SHA256_MAC_LEN;
+       crypto_hash_finish(hash, digest, &len);
 }
 
 
 /* a counter-based KDF based on NIST SP800-108 */
-void eap_pwd_kdf(u8 *key, int keylen, u8 *label, int labellen,
-                u8 *result, int resultbitlen)
+static int eap_pwd_kdf(const u8 *key, size_t keylen, const u8 *label,
+                      size_t labellen, u8 *result, size_t resultbitlen)
 {
-       HMAC_CTX hctx;
-       unsigned char digest[SHA256_DIGEST_LENGTH];
+       struct crypto_hash *hash;
+       u8 digest[SHA256_MAC_LEN];
        u16 i, ctr, L;
-       int resultbytelen, len = 0;
-       unsigned int mdlen = SHA256_DIGEST_LENGTH;
-       unsigned char mask = 0xff;
+       size_t resultbytelen, len = 0, mdlen;
 
-       resultbytelen = (resultbitlen + 7)/8;
+       resultbytelen = (resultbitlen + 7) / 8;
        ctr = 0;
        L = htons(resultbitlen);
        while (len < resultbytelen) {
-               ctr++; i = htons(ctr);
-               HMAC_Init(&hctx, key, keylen, EVP_sha256());
+               ctr++;
+               i = htons(ctr);
+               hash = crypto_hash_init(CRYPTO_HASH_ALG_HMAC_SHA256,
+                                       key, keylen);
+               if (hash == NULL)
+                       return -1;
                if (ctr > 1)
-                       HMAC_Update(&hctx, digest, mdlen);
-               HMAC_Update(&hctx, (u8 *) &i, sizeof(u16));
-               HMAC_Update(&hctx, label, labellen);
-               HMAC_Update(&hctx, (u8 *) &L, sizeof(u16));
-               HMAC_Final(&hctx, digest, &mdlen);
-               if ((len + (int) mdlen) > resultbytelen)
+                       crypto_hash_update(hash, digest, SHA256_MAC_LEN);
+               crypto_hash_update(hash, (u8 *) &i, sizeof(u16));
+               crypto_hash_update(hash, label, labellen);
+               crypto_hash_update(hash, (u8 *) &L, sizeof(u16));
+               mdlen = SHA256_MAC_LEN;
+               if (crypto_hash_finish(hash, digest, &mdlen) < 0)
+                       return -1;
+               if ((len + mdlen) > resultbytelen)
                        os_memcpy(result + len, digest, resultbytelen - len);
                else
                        os_memcpy(result + len, digest, mdlen);
                len += mdlen;
-               HMAC_CTX_cleanup(&hctx);
        }
 
        /* since we're expanding to a bit length, mask off the excess */
        if (resultbitlen % 8) {
+               u8 mask = 0xff;
                mask <<= (8 - (resultbitlen % 8));
                result[resultbytelen - 1] &= mask;
        }
+
+       return 0;
 }
 
 
@@ -85,9 +91,10 @@ int compute_password_element(EAP_PWD_group *grp, u16 num,
                             u8 *id_peer, int id_peer_len, u8 *token)
 {
        BIGNUM *x_candidate = NULL, *rnd = NULL, *cofactor = NULL;
-       HMAC_CTX ctx;
-       unsigned char pwe_digest[SHA256_DIGEST_LENGTH], *prfbuf = NULL, ctr;
-       int nid, is_odd, primebitlen, primebytelen, ret = 0;
+       struct crypto_hash *hash;
+       unsigned char pwe_digest[SHA256_MAC_LEN], *prfbuf = NULL, ctr;
+       int nid, is_odd, ret = 0;
+       size_t primebytelen, primebitlen;
 
        switch (num) { /* from IANA registry for IKE D-H groups */
         case 19:
@@ -167,20 +174,23 @@ int compute_password_element(EAP_PWD_group *grp, u16 num,
                 *    pwd-seed = H(token | peer-id | server-id | password |
                 *                 counter)
                 */
-               H_Init(&ctx);
-               H_Update(&ctx, token, sizeof(u32));
-               H_Update(&ctx, id_peer, id_peer_len);
-               H_Update(&ctx, id_server, id_server_len);
-               H_Update(&ctx, password, password_len);
-               H_Update(&ctx, &ctr, sizeof(ctr));
-               H_Final(&ctx, pwe_digest);
-
-               BN_bin2bn(pwe_digest, SHA256_DIGEST_LENGTH, rnd);
-
-               eap_pwd_kdf(pwe_digest, SHA256_DIGEST_LENGTH,
-                           (unsigned char *) "EAP-pwd Hunting And Pecking",
-                           os_strlen("EAP-pwd Hunting And Pecking"),
-                           prfbuf, primebitlen);
+               hash = eap_pwd_h_init();
+               if (hash == NULL)
+                       goto fail;
+               eap_pwd_h_update(hash, token, sizeof(u32));
+               eap_pwd_h_update(hash, id_peer, id_peer_len);
+               eap_pwd_h_update(hash, id_server, id_server_len);
+               eap_pwd_h_update(hash, password, password_len);
+               eap_pwd_h_update(hash, &ctr, sizeof(ctr));
+               eap_pwd_h_final(hash, pwe_digest);
+
+               BN_bin2bn(pwe_digest, SHA256_MAC_LEN, rnd);
+
+               if (eap_pwd_kdf(pwe_digest, SHA256_MAC_LEN,
+                               (u8 *) "EAP-pwd Hunting And Pecking",
+                               os_strlen("EAP-pwd Hunting And Pecking"),
+                               prfbuf, primebitlen) < 0)
+                       goto fail;
 
                BN_bin2bn(prfbuf, primebytelen, x_candidate);
 
@@ -276,9 +286,9 @@ int compute_keys(EAP_PWD_group *grp, BN_CTX *bnctx, BIGNUM *k,
                 u8 *confirm_peer, u8 *confirm_server,
                 u32 *ciphersuite, u8 *msk, u8 *emsk)
 {
-       HMAC_CTX ctx;
-       u8 mk[SHA256_DIGEST_LENGTH], *cruft;
-       u8 session_id[SHA256_DIGEST_LENGTH + 1];
+       struct crypto_hash *hash;
+       u8 mk[SHA256_MAC_LEN], *cruft;
+       u8 session_id[SHA256_MAC_LEN + 1];
        u8 msk_emsk[EAP_MSK_LEN + EAP_EMSK_LEN];
        int offset;
 
@@ -290,37 +300,46 @@ int compute_keys(EAP_PWD_group *grp, BN_CTX *bnctx, BIGNUM *k,
         *      scal_s)
         */
        session_id[0] = EAP_TYPE_PWD;
-       H_Init(&ctx);
-       H_Update(&ctx, (u8 *)ciphersuite, sizeof(u32));
+       hash = eap_pwd_h_init();
+       if (hash == NULL) {
+               os_free(cruft);
+               return -1;
+       }
+       eap_pwd_h_update(hash, (u8 *) ciphersuite, sizeof(u32));
        offset = BN_num_bytes(grp->order) - BN_num_bytes(peer_scalar);
        os_memset(cruft, 0, BN_num_bytes(grp->prime));
        BN_bn2bin(peer_scalar, cruft + offset);
-       H_Update(&ctx, cruft, BN_num_bytes(grp->order));
+       eap_pwd_h_update(hash, cruft, BN_num_bytes(grp->order));
        offset = BN_num_bytes(grp->order) - BN_num_bytes(server_scalar);
        os_memset(cruft, 0, BN_num_bytes(grp->prime));
        BN_bn2bin(server_scalar, cruft + offset);
-       H_Update(&ctx, cruft, BN_num_bytes(grp->order));
-       H_Final(&ctx, &session_id[1]);
+       eap_pwd_h_update(hash, cruft, BN_num_bytes(grp->order));
+       eap_pwd_h_final(hash, &session_id[1]);
 
        /* then compute MK = H(k | confirm-peer | confirm-server) */
-       H_Init(&ctx);
+       hash = eap_pwd_h_init();
+       if (hash == NULL) {
+               os_free(cruft);
+               return -1;
+       }
        offset = BN_num_bytes(grp->prime) - BN_num_bytes(k);
        os_memset(cruft, 0, BN_num_bytes(grp->prime));
        BN_bn2bin(k, cruft + offset);
-       H_Update(&ctx, cruft, BN_num_bytes(grp->prime));
-       H_Update(&ctx, confirm_peer, SHA256_DIGEST_LENGTH);
-       H_Update(&ctx, confirm_server, SHA256_DIGEST_LENGTH);
-       H_Final(&ctx, mk);
+       eap_pwd_h_update(hash, cruft, BN_num_bytes(grp->prime));
+       os_free(cruft);
+       eap_pwd_h_update(hash, confirm_peer, SHA256_MAC_LEN);
+       eap_pwd_h_update(hash, confirm_server, SHA256_MAC_LEN);
+       eap_pwd_h_final(hash, mk);
 
        /* stretch the mk with the session-id to get MSK | EMSK */
-       eap_pwd_kdf(mk, SHA256_DIGEST_LENGTH,
-                   session_id, SHA256_DIGEST_LENGTH+1,
-                   msk_emsk, (EAP_MSK_LEN + EAP_EMSK_LEN) * 8);
+       if (eap_pwd_kdf(mk, SHA256_MAC_LEN,
+                       session_id, SHA256_MAC_LEN + 1,
+                       msk_emsk, (EAP_MSK_LEN + EAP_EMSK_LEN) * 8) < 0) {
+               return -1;
+       }
 
        os_memcpy(msk, msk_emsk, EAP_MSK_LEN);
        os_memcpy(emsk, msk_emsk + EAP_MSK_LEN, EAP_EMSK_LEN);
 
-       os_free(cruft);
-
        return 1;
 }