Commit 4a56d9a2 authored by Serguei E. Leontiev's avatar Serguei E. Leontiev Committed by Dr. Stephen Henson
Browse files

Replace manual ASN1 decoder with ASN1_get_object 

Replace manual ASN.1 decoder with ASN1_get object. This
will decode the tag and length properly and check against
it does not exceed the supplied buffer length.

PR#3335
parent 89e67474

ssl/s3_srvr.c

+7 −16
Original line number Diff line number Diff line
@@ -2979,6 +2979,8 @@ int ssl3_get_client_key_exchange(SSL *s) 
			unsigned char premaster_secret[32], *start;

			size_t outlen=32, inlen;

			unsigned long alg_a;

			int Ttag, Tclass;

			long Tlen;



			/* Get our certificate private key*/

			alg_a = s->s3->tmp.new_cipher->algorithm_auth;
@@ -3000,26 +3002,15 @@ int ssl3_get_client_key_exchange(SSL *s) 
					ERR_clear_error();

				}

			/* Decrypt session key */

			if ((*p!=( V_ASN1_SEQUENCE| V_ASN1_CONSTRUCTED))) 

				{

				SSLerr(SSL_F_SSL3_GET_CLIENT_KEY_EXCHANGE,SSL_R_DECRYPTION_FAILED);

				goto gerr;

				}

			if (p[1] == 0x81)

				{

				start = p+3;

				inlen = p[2];

				}

			else if (p[1] < 0x80)

				{

				start = p+2;

				inlen = p[1];

				}

			else

			if (ASN1_get_object((const unsigned char **)&p, &Tlen, &Ttag, &Tclass, n) != V_ASN1_CONSTRUCTED || 

				Ttag != V_ASN1_SEQUENCE ||

			 	Tclass != V_ASN1_UNIVERSAL) 

				{

				SSLerr(SSL_F_SSL3_GET_CLIENT_KEY_EXCHANGE,SSL_R_DECRYPTION_FAILED);

				goto gerr;

				}

			start = p;

			inlen = Tlen;

			if (EVP_PKEY_decrypt(pkey_ctx,premaster_secret,&outlen,start,inlen) <=0) 



				{