diff options
Diffstat (limited to 'crypto/rsa/rsa_sign.c')
| -rw-r--r-- | crypto/rsa/rsa_sign.c | 21 |
1 files changed, 20 insertions, 1 deletions
diff --git a/crypto/rsa/rsa_sign.c b/crypto/rsa/rsa_sign.c index 743dfd76501e..de6ceeb0beb9 100644 --- a/crypto/rsa/rsa_sign.c +++ b/crypto/rsa/rsa_sign.c @@ -155,6 +155,25 @@ int RSA_sign(int type, const unsigned char *m, unsigned int m_len, return(ret); } +/* + * Check DigestInfo structure does not contain extraneous data by reencoding + * using DER and checking encoding against original. + */ +static int rsa_check_digestinfo(X509_SIG *sig, const unsigned char *dinfo, int dinfolen) + { + unsigned char *der = NULL; + int derlen; + int ret = 0; + derlen = i2d_X509_SIG(sig, &der); + if (derlen <= 0) + return 0; + if (derlen == dinfolen && !memcmp(dinfo, der, derlen)) + ret = 1; + OPENSSL_cleanse(der, derlen); + OPENSSL_free(der); + return ret; + } + int RSA_verify(int dtype, const unsigned char *m, unsigned int m_len, unsigned char *sigbuf, unsigned int siglen, RSA *rsa) { @@ -215,7 +234,7 @@ int RSA_verify(int dtype, const unsigned char *m, unsigned int m_len, if (sig == NULL) goto err; /* Excess data can be used to create forgeries */ - if(p != s+i) + if(p != s+i || !rsa_check_digestinfo(sig, s, i)) { RSAerr(RSA_F_RSA_VERIFY,RSA_R_BAD_SIGNATURE); goto err; |