From 6ea04154dc17c37083717d8a8bb86f4bc9f0dee5 Mon Sep 17 00:00:00 2001 From: "Dr. Stephen Henson" Date: Wed, 17 Feb 2016 15:05:27 +0000 Subject: [PATCH] Extract compression form in EC_KEY_oct2key(). MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit Extract compression form in EC_KEY_oct2key() instead of manually in the ASN.1 code. For custom curves do not assume the initial octet is the compression form: it isn't for X25519 et al. Reviewed-by: Rich Salz Reviewed-by: Emilia Käsper --- crypto/ec/ec_asn1.c | 21 ++------------------- crypto/ec/ec_key.c | 13 ++++++++++++- 2 files changed, 14 insertions(+), 20 deletions(-) diff --git a/crypto/ec/ec_asn1.c b/crypto/ec/ec_asn1.c index f033613993..4e02e5a7a1 100644 --- a/crypto/ec/ec_asn1.c +++ b/crypto/ec/ec_asn1.c @@ -1039,17 +1039,7 @@ EC_KEY *d2i_ECPrivateKey(EC_KEY **a, const unsigned char **in, long len) pub_oct = ASN1_STRING_data(priv_key->publicKey); pub_oct_len = ASN1_STRING_length(priv_key->publicKey); - /* - * The first byte - point conversion form - must be present. - */ - if (pub_oct_len <= 0) { - ECerr(EC_F_D2I_ECPRIVATEKEY, EC_R_BUFFER_TOO_SMALL); - goto err; - } - /* Save the point conversion form. */ - ret->conv_form = (point_conversion_form_t) (pub_oct[0] & ~0x01); - if (!EC_POINT_oct2point(ret->group, ret->pub_key, - pub_oct, (size_t)(pub_oct_len), NULL)) { + if (!EC_KEY_oct2key(ret, pub_oct, pub_oct_len, NULL)) { ECerr(EC_F_D2I_ECPRIVATEKEY, ERR_R_EC_LIB); goto err; } @@ -1201,17 +1191,10 @@ EC_KEY *o2i_ECPublicKey(EC_KEY **a, const unsigned char **in, long len) return 0; } ret = *a; - if (ret->pub_key == NULL && - (ret->pub_key = EC_POINT_new(ret->group)) == NULL) { - ECerr(EC_F_O2I_ECPUBLICKEY, ERR_R_MALLOC_FAILURE); - return 0; - } - if (!EC_POINT_oct2point(ret->group, ret->pub_key, *in, len, NULL)) { + if (!EC_KEY_oct2key(ret, *in, len, NULL)) { ECerr(EC_F_O2I_ECPUBLICKEY, ERR_R_EC_LIB); return 0; } - /* save the point conversion form */ - ret->conv_form = (point_conversion_form_t) (*in[0] & ~0x01); *in += len; return ret; } diff --git a/crypto/ec/ec_key.c b/crypto/ec/ec_key.c index e488523654..f09edbbc05 100644 --- a/crypto/ec/ec_key.c +++ b/crypto/ec/ec_key.c @@ -552,7 +552,18 @@ int EC_KEY_oct2key(EC_KEY *key, const unsigned char *buf, size_t len, key->pub_key = EC_POINT_new(key->group); if (key->pub_key == NULL) return 0; - return EC_POINT_oct2point(key->group, key->pub_key, buf, len, ctx); + if (EC_POINT_oct2point(key->group, key->pub_key, buf, len, ctx) == 0) + return 0; + /* + * Save the point conversion form. + * For non-custom curves the first octet of the buffer (excluding + * the last significant bit) contains the point conversion form. + * EC_POINT_oct2point() has already performed sanity checking of + * the buffer so we know it is valid. + */ + if ((key->group->meth->flags & EC_FLAGS_CUSTOM_CURVE) == 0) + key->conv_form = (point_conversion_form_t)(buf[0] & ~0x01); + return 1; } size_t EC_KEY_priv2oct(const EC_KEY *eckey, unsigned char *buf, size_t len) -- 2.34.1