Add more error checks to signature_from_string().
git-svn-id: svn+ssh://svn.berlios.de/svnroot/repos/libssh/trunk@538 7dcaeef0-15fb-0310-b436-a5af3365683c
Этот коммит содержится в:
Andreas Schneider
родитель
3df5a0dabe
Коммит
4308bb559c
288
libssh/keys.c
288
libssh/keys.c
@ -849,141 +849,207 @@ static STRING *signature_to_string(SIGNATURE *sign) {
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}
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/* TODO : split this function in two so it becomes smaller */
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SIGNATURE *signature_from_string(SSH_SESSION *session, STRING *signature,PUBLIC_KEY *pubkey,int needed_type){
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SIGNATURE *signature_from_string(SSH_SESSION *session, STRING *signature,
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PUBLIC_KEY *pubkey, int needed_type) {
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SIGNATURE *sign = NULL;
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BUFFER *tmpbuf = NULL;
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STRING *rs = NULL;
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STRING *type_s = NULL;
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STRING *e = NULL;
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char *type = NULL;
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int len;
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int rsalen;
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#ifdef HAVE_LIBGCRYPT
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gcry_sexp_t sig;
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gcry_sexp_t sig;
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#elif defined HAVE_LIBCRYPTO
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DSA_SIG *sig;
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STRING *r,*s;
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DSA_SIG *sig = NULL;
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STRING *r = NULL;
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STRING *s = NULL;
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#endif
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SIGNATURE *sign;
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BUFFER *tmpbuf;
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STRING *rs;
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STRING *type_s,*e;
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int len,rsalen;
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char *type;
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sign = malloc(sizeof(SIGNATURE));
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if (sign == NULL) {
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ssh_set_error(session, SSH_FATAL, "No space left");
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return NULL;
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}
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sign = malloc(sizeof(SIGNATURE));
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if (sign == NULL) {
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ssh_set_error(session, SSH_FATAL, "Not enough space");
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return NULL;
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}
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tmpbuf = buffer_new();
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if (tmpbuf == NULL) {
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ssh_set_error(session, SSH_FATAL, "No space left");
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signature_free(sign);
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return NULL;
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}
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tmpbuf = buffer_new();
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if (tmpbuf == NULL) {
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ssh_set_error(session, SSH_FATAL, "Not enough space");
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signature_free(sign);
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return NULL;
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}
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buffer_add_data(tmpbuf,signature->string,string_len(signature));
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type_s=buffer_get_ssh_string(tmpbuf);
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if(!type_s){
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ssh_set_error(session,SSH_FATAL,"Invalid signature packet");
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if (buffer_add_data(tmpbuf, signature->string, string_len(signature)) < 0) {
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signature_free(sign);
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buffer_free(tmpbuf);
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return NULL;
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}
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type_s = buffer_get_ssh_string(tmpbuf);
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if (type_s == NULL) {
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ssh_set_error(session, SSH_FATAL, "Invalid signature packet");
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signature_free(sign);
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buffer_free(tmpbuf);
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return NULL;
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}
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type = string_to_char(type_s);
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free(type_s);
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if (type == NULL) {
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signature_free(sign);
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buffer_free(tmpbuf);
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return NULL;
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}
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switch(needed_type) {
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case TYPE_DSS:
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if (strcmp(type, "ssh-dss") != 0) {
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ssh_set_error(session, SSH_FATAL, "Invalid signature type: %s", type);
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signature_free(sign);
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buffer_free(tmpbuf);
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SAFE_FREE(type);
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return NULL;
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}
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type=string_to_char(type_s);
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free(type_s);
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switch(needed_type){
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case TYPE_DSS:
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if(strcmp(type,"ssh-dss")){
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ssh_set_error(session,SSH_FATAL,"Invalid signature type : %s",type);
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signature_free(sign);
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buffer_free(tmpbuf);
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free(type);
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return NULL;
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}
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break;
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case TYPE_RSA:
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if(strcmp(type,"ssh-rsa")){
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ssh_set_error(session,SSH_FATAL,"Invalid signature type : %s",type);
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signature_free(sign);
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buffer_free(tmpbuf);
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free(type);
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return NULL;
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}
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break;
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default:
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ssh_set_error(session,SSH_FATAL,"Invalid signature type : %s",type);
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free(type);
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signature_free(sign);
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buffer_free(tmpbuf);
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return NULL;
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}
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free(type);
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switch(needed_type){
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case TYPE_DSS:
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rs=buffer_get_ssh_string(tmpbuf);
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buffer_free(tmpbuf);
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if(!rs || string_len(rs)!=40){ /* 40 is the dual signature blob len. */
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if(rs)
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free(rs);
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signature_free(sign);
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return NULL;
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}
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/* we make use of strings (because we have all-made functions to convert them to bignums (ou pas ;)*/
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}
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break;
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case TYPE_RSA:
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if (strcmp(type, "ssh-rsa")) {
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ssh_set_error(session, SSH_FATAL, "Invalid signature type: %s", type);
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signature_free(sign);
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buffer_free(tmpbuf);
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SAFE_FREE(type);
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return NULL;
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}
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break;
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default:
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ssh_set_error(session, SSH_FATAL, "Invalid signature type: %s", type);
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signature_free(sign);
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buffer_free(tmpbuf);
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SAFE_FREE(type);
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return NULL;
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}
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SAFE_FREE(type);
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switch(needed_type) {
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case TYPE_DSS:
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rs = buffer_get_ssh_string(tmpbuf);
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buffer_free(tmpbuf);
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/* 40 is the dual signature blob len. */
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if (rs == NULL || string_len(rs) != 40) {
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string_free(rs);
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signature_free(sign);
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return NULL;
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}
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/* we make use of strings (because we have all-made functions to convert
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* them to bignums (ou pas ;) */
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#ifdef HAVE_LIBGCRYPT
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gcry_sexp_build(&sig,NULL,"(sig-val(dsa(r %b)(s %b)))",20,rs->string,20,rs->string+20);
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if (gcry_sexp_build(&sig, NULL, "(sig-val(dsa(r %b)(s %b)))",
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20 ,rs->string, 20, rs->string + 20)) {
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string_free(rs);
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signature_free(sign);
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return NULL;
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}
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#elif defined HAVE_LIBCRYPTO
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r=string_new(20);
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s=string_new(20);
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string_fill(r,rs->string,20);
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string_fill(s,rs->string+20,20);
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sig=DSA_SIG_new();
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sig->r=make_string_bn(r); /* is that really portable ? Openssh's hack isn't better */
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sig->s=make_string_bn(s);
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free(r);
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free(s);
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r = string_new(20);
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s = string_new(20);
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if (r == NULL || s == NULL) {
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string_free(r);
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string_free(s);
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string_free(rs);
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signature_free(sign);
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return NULL;
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}
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string_fill(r, rs->string, 20);
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string_fill(s, rs->string + 20, 20);
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sig = DSA_SIG_new();
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if (sig == NULL) {
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string_free(r);
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string_free(s);
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string_free(rs);
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signature_free(sign);
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return NULL;
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}
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sig->r = make_string_bn(r); /* is that really portable ? Openssh's hack isn't better */
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sig->s = make_string_bn(s);
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string_free(r);
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string_free(s);
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if (sig->r == NULL || sig->s == NULL) {
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string_free(rs);
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DSA_SIG_free(sig);
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signature_free(sign);
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return NULL;
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}
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#endif
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#ifdef DEBUG_CRYPTO
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ssh_print_hexa("r",rs->string,20);
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ssh_print_hexa("s",rs->string+20,20);
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ssh_print_hexa("r", rs->string, 20);
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ssh_print_hexa("s", rs->string + 20, 20);
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#endif
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free(rs);
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sign->type=TYPE_DSS;
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sign->dsa_sign=sig;
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return sign;
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case TYPE_RSA:
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e=buffer_get_ssh_string(tmpbuf);
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buffer_free(tmpbuf);
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if(e == NULL) {
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signature_free(sign);
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return NULL;
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}
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len=string_len(e);
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string_free(rs);
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sign->type = TYPE_DSS;
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sign->dsa_sign = sig;
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return sign;
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case TYPE_RSA:
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e = buffer_get_ssh_string(tmpbuf);
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buffer_free(tmpbuf);
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if (e == NULL) {
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signature_free(sign);
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return NULL;
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}
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len = string_len(e);
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#ifdef HAVE_LIBGCRYPT
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rsalen=(gcry_pk_get_nbits(pubkey->rsa_pub)+7)/8;
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rsalen = (gcry_pk_get_nbits(pubkey->rsa_pub) + 7) / 8;
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#elif defined HAVE_LIBCRYPTO
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rsalen=RSA_size(pubkey->rsa_pub);
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rsalen = RSA_size(pubkey->rsa_pub);
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#endif
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if(len>rsalen){
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free(e);
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signature_free(sign);
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ssh_set_error(session,SSH_FATAL,"signature too big ! %d instead of %d",len,rsalen);
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return NULL;
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}
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if(len<rsalen)
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ssh_log(session,SSH_LOG_RARE,"RSA signature len %d < %d",len,rsalen);
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sign->type=TYPE_RSA;
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if (len > rsalen) {
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string_free(e);
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signature_free(sign);
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ssh_set_error(session, SSH_FATAL, "Signature too big! %d instead of %d",
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len, rsalen);
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return NULL;
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}
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if (len < rsalen) {
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ssh_log(session, SSH_LOG_RARE, "RSA signature len %d < %d",
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len, rsalen);
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}
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sign->type = TYPE_RSA;
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#ifdef HAVE_LIBGCRYPT
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gcry_sexp_build(&sig,NULL,"(sig-val(rsa(s %b)))",string_len(e),e->string);
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sign->rsa_sign=sig;
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if (gcry_sexp_build(&sig, NULL, "(sig-val(rsa(s %b)))",
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string_len(e), e->string)) {
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signature_free(sign);
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string_free(e);
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return NULL;
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}
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sign->rsa_sign = sig;
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#elif defined HAVE_LIBCRYPTO
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sign->rsa_sign=e;
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sign->rsa_sign = e;
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#endif
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#ifdef DEBUG_CRYPTO
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ssh_log(session, SSH_LOG_FUNCTIONS, "len e: %d", len);
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ssh_print_hexa("rsa signature", e->string, len);
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ssh_log(session, SSH_LOG_FUNCTIONS, "len e: %d", len);
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ssh_print_hexa("RSA signature", e->string, len);
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#endif
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#ifdef HAVE_LIBGCRYPT
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free(e);
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string_free(e);
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#endif
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return sign;
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default:
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return NULL;
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}
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return sign;
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default:
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return NULL;
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}
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return NULL;
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}
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void signature_free(SIGNATURE *sign) {
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