From: Dr. Stephen Henson Date: Thu, 29 Sep 2016 18:24:26 +0000 (+0100) Subject: SRP code tidy. X-Git-Tag: OpenSSL_1_1_0c~102 X-Git-Url: https://git.librecmc.org/?a=commitdiff_plain;h=3f39423aac144bf10f04f8d7b069e72bac9fff98;p=oweals%2Fopenssl.git SRP code tidy. Tidy up srp_Calc_k and SRP_Calc_u by making them a special case of srp_Calc_xy which performs SHA1(PAD(x) | PAD(y)). This addresses an OCAP Audit issue. Reviewed-by: Rich Salz (cherry picked from commit 8f332ac962b377a52016927e6db7a15367cb839c) --- diff --git a/crypto/srp/srp_lib.c b/crypto/srp/srp_lib.c index ddd86b7517..e79352cb2e 100644 --- a/crypto/srp/srp_lib.c +++ b/crypto/srp/srp_lib.c @@ -14,92 +14,40 @@ # include # include "internal/bn_srp.h" -static BIGNUM *srp_Calc_k(const BIGNUM *N, const BIGNUM *g) -{ - /* k = SHA1(N | PAD(g)) -- tls-srp draft 8 */ +/* calculate = SHA1(PAD(x) || PAD(y)) */ +static BIGNUM *srp_Calc_xy(const BIGNUM *x, const BIGNUM *y, const BIGNUM *N) +{ unsigned char digest[SHA_DIGEST_LENGTH]; unsigned char *tmp = NULL; - EVP_MD_CTX *ctxt = NULL; - int longg; - int longN = BN_num_bytes(N); + int numN = BN_num_bytes(N); BIGNUM *res = NULL; - - if (BN_ucmp(g, N) >= 0) + if (x != N && BN_ucmp(x, N) >= 0) return NULL; - - ctxt = EVP_MD_CTX_new(); - if (ctxt == NULL) + if (y != N && BN_ucmp(y, N) >= 0) return NULL; - if ((tmp = OPENSSL_malloc(longN)) == NULL) - goto err; - BN_bn2bin(N, tmp); - - if (!EVP_DigestInit_ex(ctxt, EVP_sha1(), NULL) - || !EVP_DigestUpdate(ctxt, tmp, longN)) + if ((tmp = OPENSSL_malloc(numN * 2)) == NULL) goto err; - - memset(tmp, 0, longN); - longg = BN_bn2bin(g, tmp); - /* use the zeros behind to pad on left */ - if (!EVP_DigestUpdate(ctxt, tmp + longg, longN - longg) - || !EVP_DigestUpdate(ctxt, tmp, longg)) - goto err; - - if (!EVP_DigestFinal_ex(ctxt, digest, NULL)) + if (BN_bn2binpad(x, tmp, numN) < 0 + || BN_bn2binpad(y, tmp + numN, numN) < 0 + || !EVP_Digest(tmp, numN * 2, digest, NULL, EVP_sha1(), NULL)) goto err; res = BN_bin2bn(digest, sizeof(digest), NULL); err: OPENSSL_free(tmp); - EVP_MD_CTX_free(ctxt); return res; } +static BIGNUM *srp_Calc_k(const BIGNUM *N, const BIGNUM *g) +{ + /* k = SHA1(N | PAD(g)) -- tls-srp draft 8 */ + return srp_Calc_xy(N, g, N); +} + BIGNUM *SRP_Calc_u(const BIGNUM *A, const BIGNUM *B, const BIGNUM *N) { /* k = SHA1(PAD(A) || PAD(B) ) -- tls-srp draft 8 */ - - BIGNUM *u = NULL; - unsigned char cu[SHA_DIGEST_LENGTH]; - unsigned char *cAB = NULL; - EVP_MD_CTX *ctxt = NULL; - int longN; - if ((A == NULL) || (B == NULL) || (N == NULL)) - return NULL; - - if (BN_ucmp(A, N) >= 0 || BN_ucmp(B, N) >= 0) - return NULL; - - longN = BN_num_bytes(N); - - ctxt = EVP_MD_CTX_new(); - if (ctxt == NULL) - return NULL; - if ((cAB = OPENSSL_malloc(2 * longN)) == NULL) - goto err; - - memset(cAB, 0, longN); - - if (!EVP_DigestInit_ex(ctxt, EVP_sha1(), NULL) - || !EVP_DigestUpdate(ctxt, cAB + BN_bn2bin(A, cAB + longN), longN) - || !EVP_DigestUpdate(ctxt, cAB + BN_bn2bin(B, cAB + longN), longN)) - goto err; - - if (!EVP_DigestFinal_ex(ctxt, cu, NULL)) - goto err; - - if ((u = BN_bin2bn(cu, sizeof(cu), NULL)) == NULL) - goto err; - if (BN_is_zero(u)) { - BN_free(u); - u = NULL; - } - - err: - OPENSSL_free(cAB); - EVP_MD_CTX_free(ctxt); - - return u; + return srp_Calc_xy(A, B, N); } BIGNUM *SRP_Calc_server_key(const BIGNUM *A, const BIGNUM *v, const BIGNUM *u,